Vestibular Disorders

Advance Praise for Vestibular Disorders: A Case-Study

Approach to Diagnosis and Treatment

This latest edition of Vestibular Disorders: A Case-Study Approach to Diagnosis and Treatment by
Drs Furman, Cass, and Whitney offers the reader an up-to-date series of case studies that explores
both common and unusual causes of dizziness and postural instability. Each author brings a unique
perspective to the book with their neurologic, otologic, and rehabilitative training and expertise. As
with the first edition, the case study format allows for easy readability and gives the authors an
opportunity to discuss all aspects of each case from history, examination, testing, diagnosis, and
therapy. Anyone who diagnoses and treats these often challenging cases will find this text enjoyable
and rewarding.
Joel A. Goebel, MD, FACS, Professor and Vice Chairman, Residency Program Director, Dizziness
and Balance Center Director, Otolaryngology–Head and Neck Surgery, Washington University
School of Medicine, St. Louis, MO

This outstanding text by authors from an internationally recognised centre of excellence provides a
practical, refreshing and engaging clinical presentation based approach to understanding and
learning, which will sit well with the medical mindset. The text provides a well-illustrated,
evidence-based, structured, yet simple and comprehensive approach for the clinician who wants to
master the rudiments of managing this fascinating, but complicated group of patients. . . . The authors
have a wealth of knowledge and experience across the range of disciplines relevant to this area of
medicine and their excellent presentation and teaching approach will undoubtedly result in this third
edition of the ‘‘Pittsburgh vestibular cases’’ maintaining its position as an essential reference in the
field.
Linda M. Luxon, MBBS, BSc, FRCP, Professor of Audiovestibular Medicine, University College
London Ear Institute, London, UK

The authors have put together a superb learning tool suitable for all clinicians that see patients with
dizziness and balance disorders. The book begins with an overview of anatomy, the history,
evaluation of audiological and vestibular function, vestibular rehabilitation and of the
pharmacologic options for the dizzy patient. The book then uses more than 60 well-illustrated
cases to emphasize a series of clear teaching points. The authors have developed an engaging and
highly practical text that allows the reader to learn about vestibular and balance disorders based on
real-life cases. This third edition of this popular book is another success that should be in the library of
all those with an interest in vestibular disorders.
Terry D. Fife, MD, FAAN, FANS, Balance Center, Barrow Neurological Institute, Associate
Professor of Clinical Neurology, University of Arizona College of Medicine, Phoenix, AZ
Vestibular Disorders

A Case-Study Approach to
Diagnosis and Treatment

Third Edition

Joseph M. Furman, MD, PhD

Department of Otolaryngology
University of Pittsburgh Medical Center
Pittsburgh, PA
Stephen P. Cass, MD, MPH
Department of Otolaryngology
University of Colorado Health Sciences Center
Denver, CO
Susan L. Whitney, PT, PhD
Department of Physical Therapy
University of Pittsburgh
Pittsburgh, PA

1
2010
1
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Library of Congress Cataloging-in-Publication Data

Furman, Joseph M., 1952–
Vestibular disorders : a case-study approach to diagnosis and treatment / Joseph M. Furman,
Stephen P. Cass, and Susan L. Whitney.
p. ; cm.
Includes bibliographical references and index.
ISBN 978-0-19-533320-6 (alk. paper)
1. Vestibular apparatus—Diseases—Case studies. I. Cass, Stephen P., 1957–
II. Whitney, Susan L. III. Title.
[DNLM: 1. Vestibular Diseases—Case Reports. 2. Dizziness—Case Reports. 3. Postural Balance—Case Reports.
WV 255 F986va 2010]
RF260.F87 2010
617.80 82—dc22
2009021873

The science of medicine is a rapidly changing field. As new research and clinical experience broaden our knowledge, changes in
treatment and drug therapy occur. The author and publisher of this work have checked with sources believed to be reliable in their
efforts to provide information that is accurate and complete, and in accordance with the standards accepted at the time of
publication. However, in light of the possibility of human error or changes in the practice of medicine, neither the author, nor the
publisher, nor any other party who has been involved in the preparation or publication of this work warrants that the information
contained herein is in every respect accurate or complete. Readers are encouraged to confirm the information contained herein
with other reliable sources, and are strongly advised to check the product information sheet provided by the pharmaceutical
company for each drug they plan to administer.

1 3 5 7 9 8 6 4 2

Printed in the United States of America

on acid-free paper
 Preface to the Third Edition

Dizziness is one of the most common complaints that patients bring to their doctors.1 As
many as 40% of adults experience clinically significant dizziness at some time in their
lives,2 and nearly one in four emergency room visits includes a complaint of dizziness.3
Even though dizziness is common, it remains a perplexing problem for most clinicians. It
can be a symptom of disease in almost any organ system, and the constellation of symptoms
presented by patients with dizziness often seems complex. Moreover, the same disorder
may present differently, depending on the patient’s personality and his or her response to
disease, lifestyle, and age.
Many patients with dizziness have an abnormality related to vestibular function or to
central nervous system processing of sensory information that is important for spatial
orientation. The pathophysiology underlying a balance disorder can be baffling because
much of vestibular physiology is grounded in physics and applied engineering, topics that
are remote to most clinicians. This mix of basic science and complex patient presentations
makes the field of vestibular disorders challenging. Nevertheless, deducing the origin of
dizziness and implementing appropriate treatment is a skill that will benefit any clinician
who encounters patients complaining of dizziness or dysequilibrium, especially primary
care physicians, otolaryngologists, neurologists, and physical therapists.
We have chosen to use a case-study approach to outline the principles and practice of the
care of patients with vestibular disorders. The use of a case-study approach is consistent
with the recent evolution of problem-based learning in the medical sciences. We have
tailored the case-study approach presented in the book so that it can be used as part of
training programs.
Our approach to vestibular disorders reflects the merging of ideas from the combined
experience of a neurologist (Dr. Furman), a neurotologic surgeon (Dr. Cass), and a physical
therapist (Dr. Whitney). We hope that this combined perspective makes this book enligh-
tening to its readers. Each case study contains relevant material regarding history, physical
examination, laboratory testing, differential diagnosis, and treatment. This material pro-
vides a springboard for discussion of either a concept in the field of vestibular disorders or
the diagnosis or treatment of a particular disease state. Practical, specific treatment options
are discussed throughout the book.
For our third edition, each of the previous cases has been updated as much as possible
based on recent advances in the field. The background material for the cases has been
updated and now includes a chapter regarding medications. We have added nine new cases
overall. All of the material in the book has been scrutinized by our new co-author
Dr. Whitney to assure that the text is understandable to physical therapists.

v
vi PREFACE TO THE THIRD EDITION

Because of the importance of understanding the underlying physiology and patho-

physiology of the conditions being discussed, Part I provides essential background
information concerning vestibular physiology, history and physical examination, vestib-
ular laboratory testing, audiology, vestibular rehabilitation, psychiatric issues, and med-
ications. Parts II through VI consist of case studies. In Part II, each of six tutorial cases
elucidates an essential principle or major issue in the field of balance disorders.
In Part III, 13 common disease cases review disorders that are frequently encountered.
Especially common disorders are discussed in several different cases, with different
specific issues addressed in each case. Part IV provides six case studies related to multiple
diagnoses to illustrate the diagnostic and treatment issues that arise when a single diagnosis
cannot account for the patient’s ailments. Part V contains 30 case studies pertaining to
unusual disorders. These cases provide the reader with an appreciation for the breadth of
the field and an awareness of the rarer cause of dizziness. Part VI includes six case studies
that address clinical controversies, including one case regarding driving and dizziness, and
one case regarding malingering.
This book is not meant as a substitute for other texts that deal specifically with the
anatomy and physiology of the vestibular system, the details of the ocular motor system, or
vestibular rehabilitation. Excellent texts are available on each of these topics. Rather, this
book spans the gap between these in-depth texts and the challenges that arise whenever a
patient presents with dizziness.

References
1. NIH Publication No. 86–76: Dizziness: Hope through Research. Prepared by the Office of
Scientific and Health Reports, NICDS, September 1986, pp 5–6.
2. National Institute on Deafness and Other Communication Disorders, NIH: A Report of the Task
Force on the National Strategic Research Plan. April 1989, p 74.
3. Koziol-McLain J et al: Orthostatic vital signs in emergency department patients. Ann Emerg
Med 20:806–810, 1991.
 Acknowledgments

We wish to acknowledge our families for their patience and support during the writing of this
book. We thank Oxford University Press for publishing the third edition of this book and
especially thank Craig Panner for his encouragement and helpful suggestions. Thank you
to Mary Lee McAndrew for her invaluable assistance in the preparation of the manuscript.

vii
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 Contents

Introduction: Guide for the Reader xiii

Parsing Table xiv

Part I: Background for Case Studies

Chapter 1. Vestibular Anatomy and Physiology 5
Chapter 2. History of the Dizzy Patient 17
Chapter 3. Physical Examination of the Dizzy Patient 22
Chapter 4. Vestibular Laboratory Testing 30
Chapter 5. Auditory System and Testing 41
Chapter 6. Vestibular Rehabilitation 46
Chapter 7. Psychiatric Aspects of Vestibular Disorders 53
Chapter 8. Medications Commonly Used to Treat Vestibular Disorders 59

Part II: Tutorial Case Studies

Case 1. Unilateral Vestibular Impairment and Vestibular
Compensation—Vestibular Neuritis 67
Case 2. Mixed Peripheral and Central Vestibular
Impairment—Cerebellopontine Angle Tumor 76
Case 3. Impaired Vestibular Compensation—Vestibular Neuritis 81
Case 4. Bilateral Vestibular Loss—Ototoxicity 86
Case 5. Anxiety and Psychiatric Dizziness—Vestibulopathy, Cause Unknown 94
Case 6. Emergency Room Management of the Dizzy
Patient—Acute Cerebellar Infarction 99

Part III: Common Disease Case Studies

Case 7. Benign Paroxysmal Positional Vertigo 107
Case 8. Migraine-Related Dizziness 117
Case 9. Meniere’s Disease—Medical Management 123
Case 10. Disequilibrium of Aging 130
Case 11. Multisensory Disequilibrium 136
Case 12. Meniere’s Disease—Nonablative Management of the Medically
Refractory Patient 140
Case 13. Labyrinthine Concussion 147

ix
x CONTENTS

Case 14. Mild Traumatic Brain Injury 152

Case 15. Decompensated Unilateral Peripheral Vestibular Loss 156
Case 16. Nonspecific Vestibulopathy 159
Case 17. Benign Recurrent Vertigo of Childhood 162
Case 18. Drug-Induced Dysequilibrium 166
Case 19. Cerebellar Degeneration 169

Part IV: Multiple Diagnosis Case Studies

Case 20. Meniere’s Disease and Migraine-Related Dizziness 177
Case 21. Head Trauma: Combined CNS, Labyrinthine, and Cervical Injury 182
Case 22. Migraine-Related Dizziness and Anxiety Disorder 186
Case 23. Benign Paroxysmal Positional Vertigo and Migraine-Related
Dizziness 191
Case 24. Meniere’s Disease and Benign Paroxysmal Positional Vertigo 195
Case 25. Benign Paroxysmal Positional Vertigo and Anxiety Disorder 199

Part V: Unusual Disease Case Studies

Case 26. Recurrent Benign Paroxysmal Positional Vertigo—Nonsurgical
Management 205
Case 27. Orthostatic Hypotension 208
Case 28. Horizontal Semicircular Canal Benign Paroxysmal Positional Vertigo 212
Case 29. Bilateral Meniere’s Disease 217
Case 30. Multiple Sclerosis 223
Case 31. Convergence Spasm 229
Case 32. Superior Semicircular Canal Dehiscence Syndrome—Tullio’s
Phenomenon 233
Case 33. Vertebrobasilar Insufficiency 239
Case 34. Chiari Malformation 244
Case 35. Orthostatic Tremor 250
Case 36. Mal de Débarquement Syndrome 254
Case 37. Wallenberg’s Syndrome—Posterior Inferior Cerebellar Artery
Syndrome 257
Case 38. Anterior Inferior Cerebellar Artery Syndrome 261
Case 39. Benign Paroxysmal Positional Vertigo-Surgical Management 266
Case 40. Drop Attacks 273
Case 41. Ramsay Hunt Syndrome 277
Case 42. Meniere’s Disease—Ablative Management of the Medically
Refractory Patient 282
Case 43. Chronic Otitis Media 289
Case 44. Decompensated Bilateral Vestibular Loss 295
Case 45. Autoimmune Inner Ear Disease 299
Case 46. Progressive Supranuclear Palsy 305
Case 47. Lithium-Induced Dizziness 309
Case 48. Congenital Inner Ear Malformations 312
Case 49. Saccadic Fixation Instability 321
Case 50. Congenital Nystagmus 326
Case 51. Otosclerotic Inner Ear Syndrome 331
Case 52. Solvent Exposure 339
 CONTENTS xi

Case 53. Wernicke’s Encephalopathy 344

Case 54. Rotational Vertebral Artery Syndrome 349
Case 55. Sleep Disorders and Vestibulopathy 353

Part VI: Clinical Controversy Case Studies

Case 56. Malingering 359
Case 57. Driving and Dizziness 363
Case 58. Cervicogenic Dizziness 368
Case 59. Acoustic Neuroma—Management 373
Case 60. Perilymphatic Fistula 379
Case 61. Vascular Cross-Compression Syndrome of the Eighth Cranial Nerve 385

Appendix of Diagnoses 390

Index 392
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 Introduction:
Guide for the Reader

The text is divided into six parts. Part I includes eight chapters that provide background
information common to many of the case studies. Topics include anatomy and physiology
of the vestibular system, history and physical examination of the dizzy patient, vestibular
laboratory testing, audiometric testing, vestibular rehabilitation, psychiatric issues, and
medications. Parts II through VI include 61 case studies. In Part II, 6 cases illustrate major
themes in the field of balance disorders; in Part III, 13 cases illustrate commonly encoun-
tered disorders; in Part IV, 6 cases illustrate how more than one disorder can be present in
the same patient; in Part V, 30 cases illustrate unusual disorders, and in Part VI, 6 cases
illustrate controversial disorders.
The material in this book can be approached in several ways. For individuals with
minimal background in the area of vestibular disorders, Part I should be read thoroughly
before beginning the case studies, which should be read in order. An alternative approach,
better suited to a more knowledgeable reader, is to read Part II, the tutorial cases, first and
refer to the material in Part I as needed. The reader can then study the common disease
cases in Parts III and IV and the unusual disease cases in Part V. More experienced
clinicians can approach the material by referring to the cases as they arise in their practice
or in their own order of interest. The cases in Part VI each address a clinical controversy in
vestibular disorders and should be of interest to all readers. To aid the reader in identifying
relevant case material, the Introduction includes a ‘‘Parsing Table,’’ which indicates which
cases discuss key historical features, that is, symptoms, and key examination features, that
is, signs. The Appendix of Diagnoses and Index are also meant to enable the reader to find
sought-after material directly. The cases are cross-referenced extensively to alert the reader
to relevant material that appears elsewhere in the text.

xiii
 Case number Case 1 Case 2 Case 3 Case 4 Case 5 Case 6 Case 7 Case 8 Case 8 Case 9 Case 9 Case 10 Case 11 Case 12 Case 13
Not during
Not During During Between During Between severe Not
Notes field Acute acute attack Acute attack attacks attack attacks episode acute
History
Vertigo Vertigo/dizziness - spontaneous XX X XX X XX X
Vertigo/dizziness - positional XX X
Vertigo/dizziness with headache X
Duration Episode duration: seconds X X X
Episode duration: minutes - hours X X X X X
Episode duration: hours - days X X
Autoimmune Severe nausea of vomiting with XX X XX
dizziness
Hearing Hearing loss in one ear X XX X X
Hearing loss in both ears
Tinnitus X XX X X
Aural (ear) fullness with dizziness XX X X
Migraine Bright lights increase symptoms XX X
Loud noises increase symptoms XX
Monthly fluctuation in dizziness X X
Vision Blurred or double vision X XX XX X
Unsteady vision during driving X X X XX XX X X X X
or quick head movements
Balance Unsteady gait XX X X X X XX X X X X
Difficulty standing X X X X
Coordination Limb coordination
Neck pain Neck pain with dizziness
Anxiety Tingling in the hands and feet XX
(paresthesias)
Palpitations or increased XX
heart rate with dizziness
Examination
Eye movement Spontaneous nystagmus XX X X XX

Gaze-Evoked nystagmus X X
Limited down gaze
Abnormal vergence eye
movements
VOR Abnormal head thrust test XX XX XX X X
Cranial nerves Facial weakness
Paroxysmal positional XX
nystagmus
Balance Positive Romberg test X XX
Positive foam Romberg test XX X X XX X X X XX
Unsteady gait XX X XX XX XX X XX X X X X

Case number Case 31 Case 32 Case 33 Case 34 Case 35 Case 36 Case 37 Case 38 Case 39 Case 40 Case 41 Case 42 Case 43
During
Notes field attack A c u te A c u te A c u te Acute
History
Vertigo Vertigo/dizziness - spontaneous X X X X XX XX
Vertigo/dizziness - positional X XX
Vertigo/dizziness with headache
Duration Episode duration: seconds X X X X X X X
Episode duration: minutes - hours X X X X X
Episode duration: hours - days X X X X X
Autoimmune Severe nausea of vomiting with X XX
dizziness

Hearing Hearing loss in one ear X X XX X

Hearing loss in both ears
Tinnitus XX
Aural (ear) fullness with dizziness X X XX X
Migraine Bright lights increase symptoms X
Loud noises increase symptoms XX
Monthly fluctuation in dizziness
Vision Blurred or double vision X X X X X XX XX X X
Unsteady vision during driving
or quick head movements X X X X X X X X X
Balance Unsteady gait X XX XX X XX X XX X
Difficulty standing XX X XX XX XX X X
Coordination Limb coordination X X
Neck pain Neck pain with dizziness X
Anxiety Tingling in the hands and feet X X
(paresthesias)

Palpitations or increased
heart rate with dizziness X
Examination
Eye movement Spontaneous nystagmus X X X X XX

Gaze-Evoked nystagmus X XX XX XX
Limited down gaze

Abnormal vergence eye XX

movements

VOR Abnormal head thrust test X XX

Cranial nerves Facial weakness X X XX
Paroxysmal positional XX
nystagmus

Balance Positive Romberg test X X X XX X XX X

Positive foam Romberg test
Unsteady gait X XX X XX XX X XX X

1) The history and examination features in this table reflect dominant symptoms and signs. Some patients may experience symptoms and signs not
marked by an "X". Also, the symptoms and signs in the illustrative cases may not exactly match the information in this table.

2) Severity is indicated by XX vs. X.

Case 14 Case 15 Case 16 Case 17 Case 17 Case 18 Case 19 Case 20 Case 21 Case 22 Case 22 Case 23 Case 24 Case 25 Case 26 Case 27 Case 28 Case 29 Case 30
Not during Not during Not during Not Acute
Not During Between During Not During Between migraine Meniere's anxiety during
acute attack attacks attack acute attack attacks episode episode episode attack

X XX X XX
X X XX XX XX XX X XX
X X X
X X X X X X X X
X X X X
X X X X X
X X

X X
X
X X X
X X X
X XX X XX
X XX X XX
X X X
X X XX X X X X XX X X X
X X X XX X X X X X XX X X XX X

X X X X X X X X X X
X X X
X X
X
XX X X X X

XX X X X

X XX X X

X X X X
X

X X

XX X X X X

XX XX XX X XX

X XX X XX
X X X X X X
X X X X XX XX XX X XX X X X XX

Case 44 Case 45 Case 46 Case 47 Case 48 Case 49 Case 50 Case 51 Case 52 Case 53 Case 54 Case 55 Case 56 Case 57 Case 58 Case 59 Case 60 Case 61
Not Not During
A c u te A c u te acute acute attack

X X X X X X
X

X X X X X
X X X X X
X X X X X X X
X X X X X X

X X X X
XX X X
X X X X X
X X X X X X X
X
X X

X X X X X X X X X X X X X X X X

XX X X XX X X X X X X X X X X X X X
X X XX X X X X X X X X X
X X X X X
X
XX

X X X

X X X

X X X

XX X X
XX X

X X
XX XX X X

XX X X X X X X X X X
X
XX XX XX X X X X X XX X XX X X
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Vestibular Disorders
This page intentionally left blank
Part I

Background for Case Studies

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1
Vestibular Anatomy and
Physiology

The vestibular labyrinth contains two types of sensors, the semicircular canals and the
otolith organs (Figure 1.1). The semicircular canals sense rotational movement; the otolith
organs sense linear motion and orientation with respect to gravity. There are three
semicircular canals, each sensitive to rotation in a particular plane. These three planes
are more or less perpendicular to one another, allowing the labyrinth to sense rotations
about any spatial axis because one or more semicircular canals are stimulated by any
particular rotation. For example, turning the head to the left and right stimulates predomi-
nantly the horizontal semicircular canals, whereas moving the head up and down stimulates
the vertical semicircular canals. Figure 1.2 depicts the orientation of the semicircular
canals in the head.
The otolith organs include the utricle and saccule. The utricle senses motion in the
horizontal plane, that is, naso-occipital (forward–backward) movement, left–right move-
ment, and combinations thereof. The saccule senses motion in the sagittal plane, such as
naso-occipital movement, up–down movement, and combinations of these movements.
The utricle and saccule also sense changes in orientation to gravity resulting from move-
ments like putting the chin on the chest (pitch) and touching the ear to the shoulder (roll) .
As can be seen in Figure 1.1, the cochlea is immediately adjacent to the vestibular
labyrinth. Both endolymph and perilymph of the vestibular labyrinth and the cochlea are
in communication with one another. The vestibular and auditory portions of the inner ear
share a common blood supply as well. Because of their nearness to one another, common
fluid spaces, and a shared blood supply, it is not surprising that disorders affecting the
vestibular labyrinth often also affect the cochlea, so that dizziness and disequilibrium are
often accompanied by hearing loss and/or tinnitus.
Each of the three semicircular canals contains an enlarged area known as the ampulla,
which is important for the transduction of rotational motion into neural activity (Figures 1.1
and 1.3). Within each ampulla is a cupula, a gelatinous membrane that completely seals the
semicircular canal. During head movement, the cupula bows like a drum head. This cupular
movement, the first step in the transduction process, activates the underlying hair cells,
which in turn are innervated by a semicircular canal nerve, which itself is a branch of the
vestibular portion of the eighth cranial nerve.
The maculae of the vestibular labyrinth are the sensory transduction regions of the
otolith organs, the utricle and saccule. The maculae are organized so that individual hair
cells sense motion in a particular direction known as its polarization vector. The arrows
shown in Figure 1.4 represent the most sensitive directions for individual hair cells on the

5
6 VESTIBULAR DISORDERS

Figure 1.1 The vestibular labyrinth contains two types of sensors, the semicircular canals and
the otolith organs. There are three semicircular canals: horizontal, superior (anterior), and
posterior (inferior). Each semicircular canal is sensitive to rotation in the plane of the canals.
The otolith organs include the utricle and saccule. The utricle senses motion both to and fro and
left and right, and also senses static pitch and roll of the head, that is, movements such as putting
the chin on the chest and touching the ear to the shoulder. The saccule senses up-and-down
motion, to-and-fro motion, and static pitch of the head. Note the proximity of the cochlea to the
vestibular labyrinth. The vestibular and auditory portions of the inner ear share a common blood
supply and inner-ear fluid metabolism.

surface of the utricular and saccular maculae. Note that for each macula there is a complete
representation of directions of motion in the horizontal plane for the utricle and in the
sagittal plane for the saccule. For example, a hair cell in the utricular macula whose
polarization vector points toward the left ear is stimulated by left-ear down-tilt or by linear
acceleration to the right.
One component of each macula is the otolithic membrane, which contains otoconia
(literally, ‘‘ear stones’’), pebble-like structures composed of crystallized calcium carbonate
(Figures 1.5 and 1.6). Otoconia are constantly being formed and reabsorbed in a process
involving the macular supporting cells and surrounding dark cells. This process of forma-
tion and absorption is probably important in the pathophysiology of benign paroxysmal
positional vertigo (see Cases 7, 23, 24, 25, 26, 28, and 34).
Hair-cell stimulation results from the bending of an array of surface ‘‘hairs,’’ or
stereocilia. Bending the array toward the tallest hair (kinocilium) causes hair-cell depolar-
ization, whereas bending the array of stereocilia away from the kinocilium causes hyper-
polarization. Depolarization of the hair cells results in an increase in the firing rate of the
Figure 1.2 The vestibular labyrinth is oriented in the temporal bone in such a way that the lateralmost
semicircular canal, which is the horizontal semicircular canal, is more or less in the head-horizontal
plane. The other two semicircular canals, oriented more or less vertically and optimally, sense the
oblique pitch-and-roll rotations of the head. The utricle lies more or less in the same plane as the
horizontal semicircular canals, which allows it to transduce translational motion forward and backward
and left and right. The saccule is oriented vertically. AC5anterior semicircular canal; HC5horizontal
semicircular canal; PC5posterior semicircular canal

Figure 1.3 Ampulla of a semicircular canal. The ampulla of each semicircular canal is an enlarged
area that is important to the transduction of rotational movement into neural activity. Within each
ampulla is a cupula, a gelatinous membrane that completely seals the semicircular canal. During head
movement, the cupula bows like a drum head; it does not flap like a swinging door. This cupular
movement, the first step in the transduction process, activates the underlying hair cells.
Source: Modified with permission from Harada Y (ed): The Vestibular Organs. Amsterdam: Kugler & Guedini, 1988,
p 64.4

7
 Striola

Figure 1.4 Maculae of the utricle and saccule. The maculae are the sensory transduction
regions of the utricle and saccule. They are organized so that individual hair cells lie in various
orientations, allowing them to optimally sense motion in a particular direction. The arrows
indicate the polarization vector, i.e., most sensitive direction for individual hair cells on the
surface of the maculae. At the center of each macula is a region called the striola, where the
orientation of the hair cells changes abruptly.
Source: With permission from Baloh RW (ed): Dizziness, Hearing Loss, and Tinnitus: The Essentials of
Neurotology. New York: Oxford University Press, 2001, p 22. 5

Figure 1.5 Otolithic macula. A component of each macula is an otolithic membrane containing
otoconia (otoconial crystals). The otoconia add mass to the otolithic membrane. The heavy otolithic
membrane deforms in response to linear motion and changes of orientation with respect to gravity.
This deformation bends the hairs of the underlying hair cells. The directional sensitivity of each hair
cell is determined by the location of the kinocilium with respect to the stereocilia.

8
 CHAPTER 1: VESTIBULAR ANATOMY AND PHYSIOLOGY 9

Figure 1.6 Scanning electron micrograph of otoconia, which are pebble-like structures
composed of crystallized calcium carbonate (CaCO3) that are constantly being formed and
reabsorbed in a process involving the macular supporting cells and surrounding dark cells.
Source: With permission from Harada Y (ed): The Vestibular Organs. Amsterdam: Kugler & Guedini,
1988, p 12. 4

eighth nerve afferents that innervate the hair cells, whereas hyperpolarization causes
decreased activity.
Each neuron in the vestibular portion of the eighth cranial nerve has a so-called resting
discharge. That is, numerous action potentials (about 90 per second) occur even with the
head at rest. This is unique for sensory organs of the body. Although these neurons require
an expenditure of energy even while the head is still, their constant high-level firing rate is
quite useful because such cells have a bidirectional response, that is, they can sense motion
in both the excitatory and inhibitory directions, continuously monitor head motion, and are
very sensitive. Vestibular neurons (Figure 1.7) increase or decrease their firing rate as a
result of depolarization or hyperpolarization, respectively, of the hair cells that they
innervate.
The information regarding head movement transduced by the peripheral vestibular
organs is relayed by the eighth cranial nerve, whose cell bodies lie in Scarpa’s ganglion,
and traverses the internal auditory canal and cerebellopontine angle before entering the
brainstem at the pontomedullary junction. The vestibular nerve synapses on cells in the
vestibular nuclei and other central nervous system structures such as the cerebellum.
Information from the vestibular nuclei both ascends and descends in the central nervous
system. Ascending pathways are important for vestibulo-ocular reflexes and for percep-
tion of vestibular sensations. Descending pathways are important for vestibulospinal
reflexes.
Also included in the vestibular nerve are the vestibular efferents, neurons that project
from the central nervous system to the labyrinth. Their function is uncertain, but they may
be involved in modulating the sensitivity of the labyrinth.
10 VESTIBULAR DISORDERS

Figure 1.7 Each neuron in the vestibular portion of the eighth cranial nerve has a so-called
resting discharge. That is, numerous action potentials (about 90 per second) occur even with the
head at rest. Although these neurons require expenditure of energy even while the head is still,
their constant high-level firing rate is useful because such cells can sense motion in both the
excitatory and inhibitory directions via depolarization or hyperpolarization that increases and
decreases eighth nerve firing rate, respectively.
Source: Adapted with permission from Kelly JP: Vestibular system. In: Kandel ER, Schwartz JH, Jessell
TM (eds). Principles of Neural Science, ed 3. Norwalk, CT: Appleton & Lange, 1991, p 506.6

The vestibular nucleus on either side of the brain is composed of at least four anatomic
subdivisions named the superior, medial, lateral, and inferior vestibular nuclei. The
vestibular nuclei receive inputs not only from the vestibular labyrinth but also from other
sensory modalities including vision, somatic sensation, and audition. As a result of these
varied sensory inputs, the name vestibular nuclei is somewhat misleading. These structures
are, in fact, sensory integration nuclei whose output influences eye movements, truncal
stability, and spatial orientation.

Vestibulo-Ocular Reflex

The vestibulo-ocular reflex (VOR) is a mechanism whereby head movement automati-

cally results in a conjugate eye movement equal and opposite to the head movement so
that the eyes stay on target. For example, a leftward head movement is associated with a
rightward eye movement of both eyes and vice versa. The VOR works for all types of
head movements, including rotation and translation. The VOR, in its simplest form, is
mediated by a three-neuron arc. For the horizontal VOR, these three neurons include the
eighth cranial nerve (neuron 1), an interneuron that arises from the vestibular nucleus and
terminates in the abducens nucleus (neuron 2), and the motoneuron to the eye muscles
(neuron 3) (Figure 1.8). Note that the excitation of the horizontal semicircular canal
excites the contralateral abducens nucleus and thus the contralateral lateral rectus. Also
stimulated, via the medial longitudinal fasciculus, which decussates (crosses), is the
ipsilateral medial rectus subnucleus of the oculomotor nucleus and thus the ipsilateral
medial rectus. Similar explanations can be applied to excitation of the anterior semicir-
cular canals, for example, caused by pitching the head down, that is, chin to the chest,
thereby causing upward deviation of both eyes; excitatory signals from the labyrinth
cross to reach the superior rectus and inferior oblique subdivisions of the contralateral
 CHAPTER 1: VESTIBULAR ANATOMY AND PHYSIOLOGY 11

Figure 1.8 Horizontal vestibulo-ocular reflex (VOR) pathways. The VOR is mediated by a three-
neuron arc that includes the eighth cranial nerve, an interneuron from the vestibular nucleus to the
abducens nucleus (VI nerve), and the motoneuron to the lateral rectus muscles. To coordinate the
movement of the two eyes, an interneuron connects the abducens nucleus to the oculomotor nucleus
(III nerve), which contains the cell bodies of the motoneurons to the medial rectus muscle. Note that
the sixth nerve nucleus contains cell bodies for the lateral rectus motoneurons as well as cell bodies for
the fibers that ascend in the medial longitudinal fasciculus to innervate the motoneurons for the medial
rectus muscle. The medial longitudinal fasciculus coordinates the action of the two eyes so that
horizontal eye movements are conjugate. Note that a lesion of the medial longitudinal fasciculus is
associated with an abnormality of adduction that manifests itself as an internuclear ophthalmoplegia.
Source: Adapted with permission from Furman JM: Nystagmus and the vestibular system. In: Podos SM, Yanoff M
(eds). Textbook of Ophthalmology. New York: Gower Medical, 1993, p 9.4.7

oculomotor nucleus. Because motor neurons to the superior rectus muscle decussate but
those to the inferior oblique muscle do not, excitation of the anterior semicircular canals
activates the ipsilateral superior rectus muscle and the contralateral inferior oblique
muscle. Similarly, excitation of the posterior semicircular canals—for example, by
pitching the head down—causes downward deviation of both eyes; excitatory signals
from the labyrinth cross to reach the contralateral rectus subnucleus and the contralateral
trochlear nucleus. This neural activity causes excitation of the ipsilateral superior oblique
muscle because of the crossed innervation of the superior oblique muscle by the trochlear
nerve. This neural activity also causes excitation of the contralateral inferior rectus
muscle because of the uncrossed innervation of the inferior rectus muscle from the
oculomotor nucleus.
One remarkable feature of the VOR is that it is produced by the coordinated action of the
two vestibular nuclear complexes, one on either side of the brainstem, which cooperate
with one another such that when one is excited, the other is inhibited. This push–pull
12 VESTIBULAR DISORDERS

behavior is a direct result of the tonic vestibular activity in the eighth cranial nerve that
allows both an increase and a decrease in neural activity during head movement. For
example, when the head is turned to the left, the activity in the left eighth cranial nerve and
left vestibular nuclei is increased, whereas the activity of the right eighth nerve and right
vestibular nuclei is decreased (Figure 1.9). This reciprocal effect greatly increases the
sensitivity of the VOR.
Operationally, the central nervous system responds to differences in activity between the
two vestibular nuclear complexes. For example, when there is no head movement, resting
neural activity within the vestibular nuclei is symmetric. However, during movement, there

Figure 1.9 Push–pull action of the horizontal vestibulo-ocular reflex. (A) With no head
movement, left and right vestibular influences are balanced. (B) With head movement to the
left, endolymph flow produces an excitatory stimulus in the left horizontal semicircular canal
and an inhibitory stimulus in the right horizontal semicircular canal. The excitatory stimulus
increases neural activity in the vestibular nerve and vestibular nuclei, and the inhibitory
stimulus decreases such activity. The brain interprets the difference in neural activity between
the vestibular nuclei as a head movement to the left and generates appropriate vestibulo-ocular
and postural responses.
 CHAPTER 1: VESTIBULAR ANATOMY AND PHYSIOLOGY 13

is asymmetric activity in the vestibular nuclei. A left–right asymmetry in the vestibular nuclei
is interpreted by the central nervous system as a head movement, even when such asymme-
tries are a result of pathology.

Vestibulospinal and Neck-Related Reflexes

Information from the vestibular labyrinth descends in the nervous system to control head
position, truncal stability, and limb position. The medial and lateral vestibulospinal tracts
(MVST and LVST) and the reticulospinal tract (RST) carry information from the
vestibular nuclei into the brainstem and spinal cord. The neck also sends neural signals
to the central nervous system regarding head position. These signals, coupled with
vestibular signals, provide information regarding head and trunk position. Signals from
the neck can cause eye movements via the cervico-ocular reflex, which is normally
almost completely inactive. Possibly, in patients with vestibular deficits, the cervico-
ocular reflex becomes more active.1,2 Another important reflex is the vestibulo-collic
reflex, whereby vestibular signals are relayed to neck muscles to stabilize the head. This
reflex may account for the neck stiffness experienced by many patients with vestibular
asymmetries.

Vestibular-Autonomic Projections

An additional projection of the vestibular system is to the autonomic nervous system,

predominantly to the sympathetic nervous system and to structures that control respiration.
Through these projections, patients with vestibular imbalance may experience nausea and
vomiting. The physiologic necessity for the vestibuloautonomic system, especially the
need for vestibular imbalance to induce nausea and vomiting, is unknown.

Effect of Unilateral Peripheral Vestibular Injury

Unilateral labyrinthine injury disrupts the reciprocal, push–pull interaction of the two
labyrinths. Following the acute loss of unilateral peripheral vestibular function, there is a
loss of resting neural activity in the vestibular nuclei ipsilateral to the lesion. Because the
brain normally detects differences in activity between the two vestibular nuclear com-
plexes, an acute loss of unilateral peripheral vestibular function is interpreted as a con-
tinuous rapid head movement (Figure 1.10). The brain responds with ‘‘corrective’’ eye
movements manifested as vestibular nystagmus.
With complete loss of unilateral vestibular function, the three semicircular canals and
the two otolith organs on one side become inactive, and the resulting eye movement and
body postures reflect the unopposed action of the contralateral labyrinth. In the case of eye
movement, there is nystagmus. The direction of the nystagmus, which is predominantly
horizontal-torsional, can be explained as follows: the remaining horizontal semicircular
canal is unopposed, thus accounting for the horizontal component; the orientation of the
two remaining vertical canals is such that their torsional (roll) influences add to each other
but their vertical (pitch) components cancel one another. The vestibulospinal manifestation
of acute unilateral peripheral vestibular loss may include head tilt. Most patients, however,
14 VESTIBULAR DISORDERS

Figure 1.10 The reciprocal push–pull interaction of the two labyrinths is disrupted after acute
peripheral labyrinthine injury. For example, following the acute loss of right unilateral
peripheral vestibular function, there is a loss of resting neural activity in the right vestibular
nerve and right vestibular nuclei. Because the brain normally detects differences in activity
between the two vestibular nuclear complexes, even when stationary, the imbalance in neural
activity is interpreted as a rapid head movement, in this case to the left.

do not have a static head tilt but do experience disequilibrium and postural instability that
includes leaning and veering of gait acutely to the side of the lesion.
The nystagmus, postural instability, and severe vegetative symptoms (e.g., nausea,
vomiting, and diaphoresis) that are associated with acute vestibular injury gradually abate
through compensatory mechanisms. This process, known as vestibular compensation,
involves changes in the vestibular nuclei that lead to partial restoration of the lost resting
neural activity within the ipsilateral vestibular nucleus, thereby reducing the asymmetry in
neural activity between the left and right vestibular nuclei (Figure 1.11A). Such changes
restore the function of the vestibulo-ocular and vestibulospinal reflexes while the person is
stationary. Vestibular compensation also improves the VOR during head movement.
(Figures 1.11B, C) The vegetative symptoms and signs resulting from stimulation of the
vestibuloautonomic projections usually resolve in concert with improvement in the
vestibulo-ocular and vestibulospinal reflexes.
Once the process of vestibular compensation has occurred, the neural activity in a single
vestibular nerve influences the neural activity within both vestibular nuclei. Although
compensation acts to rebalance brainstem vestibular activity, patients with chronic uni-
lateral peripheral vestibular loss have a reduced VOR magnitude, abnormal timing of the
VOR (see Chapter 4 regarding rotational testing), and an asymmetry of VOR during quick
head movements. Occasionally, patients may overcompensate for a peripheral vestibular
lesion and manifest a recovery nystagmus, which beats in the opposite direction from that
which occurred initially. Also, compensated patients are susceptible to decompensation,
leading to a recurrence of all or part of their acute vestibular syndrome.
The central vestibular system is profoundly influenced by the cerebellum.3 Particular
regions of the cerebellum, including the vestibulocerebellum (the flocculo-nodular lobe
and the cerebellar vermis), are particularly important for control of eye movements and
body position. Important and powerful connections between the vestibular nuclei and the
cerebellum enable the cerebellum to influence vestibular-induced eye and trunk
 (a)

(b)

(c)

Figure 1.11 When a peripheral vestibular injury is chronic, in this case on the right, the central nervous
system is able, through vestibular compensation, to partially restore the lost resting activity within the
deafferented vestibular nucleus, and thus reduce the asymmetry of neural activity between the
vestibular nuclei at rest (A) and partially restore the function of the vestibulo-ocular reflex (VOR).
(B) Movement toward the intact ear. (C) Movement toward the lesioned ear.

15
16 VESTIBULAR DISORDERS

movements. As a result, lesions of the cerebellum are frequently associated with symptoms
and signs such as gait instability and nystagmus that are indistinguishable from those seen
with peripheral vestibular lesions.
The vestibular nuclear projection to the thalamus and to the cerebral cortex allows
vestibular sensations to reach consciousness. However, these projections are not solely
vestibular because they are mixed with somatic sensation. As a result, the distinctions that
patients can make regarding other sensory systems, such as brightness, color, loudness, and
pitch, are not possible for vestibular sensation. The diffuse character of the vestibulocor-
tical projection may underlie the difficulty that patients experience when trying to describe
vestibular ailments.

References
1. Huygen PLM, Verhagen WIM, Nicolasen MGM: Cervico-ocular reflex enhancement in
labyrinthine-defective and normal subjects. Exp Brain Res 87:457–464, 1991.
2. Bronstein A, Hood J: The cervico-ocular reflex in normal subjects and patients with absent
vestibular function. Brain Res 373:399–408, 1986.
3. Ito M (ed): The Cerebellum and Neural Control. New York: Raven Press, 1984.
4. Harada Y (ed): The Vestibular Organs. Amsterdam: Kugler & Guedini, 1988.
5. Baloh RW, Honrubia V: Clinical Neurophysiology of the Vestibular System, ed 3. New York:
Oxford University Press, 2001.
6. Kelly JP: Vestibular system. In: Kandel ER, Schwartz JH, Jessell TM (eds). Principles of
Neural Science, ed 3. Norwalk, CT: Appleton & Lange, 1991, pp 584–596.
7. Furman JM: Nystagmus and the vestibular system. In: Podos SM, Yanoff M (eds). Textbook of
Ophthalmology. New York: Gower Medical, 1993, pp 9.1–9.7.
2
History of the Dizzy Patient

What is meant by the term dizziness? What is meant by the term vertigo?
Dizziness means different things to different people. Thus, sensations described by a
patient as dizziness should be further defined. Patients may use this term to mean that
they feel lightheaded, have a swimming sensation in the head, and have a sense of
disorientation or imbalance and unsteadiness. They may also mean that they have vertigo,1
an illusory sensation of motion of either the self or the surroundings. This illusory motion
can be rotational, that is, a sense of spinning or turning; translational, for example, a sense
of rising; or a static reorientation of the visual world, that is, tilting of the self or the
surroundings.
Why is interviewing a patient who suffers from dizziness often difficult, and what steps can
be taken to yield a more satisfactory history?
Patients are often unable to describe their dizziness. This difficulty is probably related to
the comparatively meager and impure neural projection from the peripheral vestibular
system to the cerebral cortex. As a result, patients do not have a vocabulary for vestibular
sensations, as they do for auditory and visual stimuli. Moreover, the vestibular information
at cerebral levels is mixed with somatic sensation, which further degrades the specificity of
vestibular complaints. Nevertheless, an attempt should be made to understand what a
patient means by dizziness. Ask the patient to describe the symptoms in his or her own
words, but be ready to assist the patient in learning a new vocabulary to describe the
symptoms by providing descriptors such as spinning, lightheadedness, giddiness, swim-
ming, and unsteadiness when walking. A little extra time spent in educating the patient
about different subjective manifestations of dizziness can help develop a mutual under-
standing of what is meant by dizziness, which will improve physician–patient commu-
nication, help the physician focus on the patient’s functional complaint, and save time and
potential frustration later.
What categories of information should be elicited in the history of a dizzy patient?
The history should include an inquiry into (1) the characteristics of the patient’s dizziness,
(2) the time course and aggravating factors regarding the dizziness, (3) associated otologic
symptoms, and (4) associated neurologic symptoms.
The first episode of dizziness is often vivid and is most typical of a particular disorder.
Over time, either normal or maladaptive compensatory mechanisms can change the
character of dizziness and obscure the diagnosis. Thus, it is often useful to begin the
history by focusing on the first episode of dizziness. Once the character of the first episode

17
18 VESTIBULAR DISORDERS

is established, review the time course of the dizziness from its inception to the present. Is
the dizziness episodic or constant? If the dizziness is episodic, note the duration, severity,
and frequency of the episodes. If it is constant, determine whether the symptoms are getting
progressively worse, slowly improving, or remaining the same.
The discovery of factors that provoke or aggravate the patient’s symptoms can provide
important clues to the diagnosis.2 Vertigo may be provoked in some people by lying down,
rolling over in bed, or pitching the head back to look up. In others, dizziness is associated
with rising quickly from a supine or seated position. Particular environmental or social
situations provoke vertigo in some individuals.
Because the hearing and vestibular apparatuses are closely linked anatomically and
functionally, an inquiry into otologic symptoms is critical. Hearing loss, tinnitus, and
aural fullness or pressure suggest involvement of the inner ear and may provide clues
regarding which ear is involved. An inquiry into the presence of neurologic symptoms
is important because of the common association of dizziness with central nervous
system disorders such as cerebellopontine angle neoplasms, multiple sclerosis,
migraine, and vertebrobasilar artery insufficiency. Visual symptoms can be caused
by both peripheral and central vestibular abnormalities and by nonvestibular central
nervous system abnormalities. Blurred vision is particularly nonspecific and can be
caused by an abnormality anywhere in the vestibular, visual, or ocular motor path-
ways. However, blurred vision that occurs only during or immediately after head
movement strongly suggests a vestibular abnormality with an impaired VOR.
Double vision strongly suggests an ocular motor abnormality but can also be seen
with vestibular system abnormalities, especially during or just after a head movement.
Loss of vision definitely points to a visual pathway abnormality or to an alteration in
level of consciousness.
Table 2–1 is a dizziness questionnaire that may be used to aid in eliciting the history.3
This questionnaire does not replace eliciting a history personally; rather, it focuses the

Table 2–1A Dizziness Questionnaire—Characteristics of Dizziness

IS YOUR DIZZINESS ASSOCIATED WITH ANY OF THE FOLLOWING SENSATIONS?

PLEASE READ THE ENTIRE LIST FIRST. THEN CIRCLE YES OR NO TO DESCRIBE YOUR
FEELINGS MOST ACCURATELY.
Yes No 1. Lightheadedness or swimming sensation in the head.
Yes No 2. Blacking out or loss of consciousness.
Yes No 3. Tendency to fall.
Yes No 4. Objects spinning or turning around you.
Yes No 5. Sensation that you are turning or spinning inside, with outside objects remaining
stationary.
Yes No 6. Loss of balance when walking in the light: Veering to the: Right? Left?
Yes No 7. Loss of balance when walking in the dark: Veering to the: Right? Left?
Yes No 8. Headache.
Yes No 9. Nausea.
Yes No 10. Vomiting.
Yes No 11. Pressure in the head.
Yes No 12. Tingling in the fingers or toes.
Yes No 13. Tingling around the mouth.
 CHAPTER 2: HISTORY OF THE DIZZY PATIENT 19

Table 2–1B Dizziness Questionnaire—Time Course and Aggravating Factors

1. When did your dizziness first occur? ___________________________________

2. How often do you become dizzy? _____________________________________
3. If dizziness occurs in attacks, how long does an attack last? _________________
Yes No 4. Do you have any warning that dizziness is about to start?
Yes No 5. Does dizziness occur at any particular time of the day or night?
Yes No 6. Are you completely free of dizziness between attacks?
Yes No 7. Does change of position make you dizzy? Which movements?
Yes No 8. Do you become dizzy when rolling over in bed?
To the right?________ To the left?_________
Yes No 9. Do you know of any possible cause for your dizziness? What? ______________
Yes No 10. Do you know of anything that will:
Yes No a. Stop your dizziness or make it better? _______________________________
_______________________________________________________________
b. Make your dizziness worse? ______________________________________
_______________________________________________________________
Yes No 11. Do you become dizzy when you bend your head forward? __________________
Backward? _______________________________________________________
Yes No 12. Do you become dizzy when you cough? ________________________________
When you sneeze? _________________________________________________
When you have a bowel movement? ___________________________________
13. Can any of the following make your dizziness worse or start an attack?
Yes No Fatigue
Yes No Exertion
Yes No Hunger
Yes No Menstrual period
Yes No Stress
Yes No Emotional upset
Yes No Alcohol
Yes No 14. Do you have any allergies? What? ______________________________________

patient’s thinking and ensures that none of the essential elements of the history are
omitted.
Which elements of the past medical history, current and previous medication use,
family history, and review of systems are important in evaluating the patient with
dizziness?
Each of the areas of the history, including the general medical history, is extremely
important because all areas provide clues to the diagnosis and pertinent comorbid
factors that can be helpful in planning further management of the patient. For example,
the review of systems may provide clues suggesting autoimmune inner ear disease,
hormonal dysfunction (reactive hypoglycemia, diabetes mellitus, thyroid dysfunction),
renal disease, neurologic disease (especially multiple sclerosis and migraine), or
chronic infection (human immunodeficiency virus [HIV], syphilis, Epstein-Barr virus).
Patients should be asked specifically about exposure to potentially ototoxic medica-
tions (e.g., aminoglycoside antibiotics, certain chemotherapeutic agents, and loop
diuretics).
Table 2–1C Dizziness Questionnaire—Associated Ear Symptoms

DO YOU HAVE ANY OF THE FOLLOWING SYMPTOMS? PLEASE CIRCLE YES OR NO

AND CIRCLE THE EAR INVOLVED, IF APPLICABLE.
Yes No 1. Dizziness. Describe dizziness ____________________________________________
Yes No 2. Difficulty in hearing? Both Ears Right Left
Yes No 3. Does your hearing change with dizziness? Yes No
If so, how? ____________________________________________________________
Yes No 4. Do you have noise in your ears? Both Ears Right Left
Describe the noise: _____________________________________________________
Yes No 5. Does noise change with dizziness? Yes No
If so, how? ___________________________________________________________
Yes No 6. Do you have fullness or stuffiness in your ears? Both Ears Right Left
Yes No 7. Do you have pain in your ears? Both Ears Right Left
Yes No 8. Do you have a discharge from your ears? Both Ears Right Left

Table 2–1D Dizziness Questionnaire—Associated Neurologic Symptoms

HAVE YOU EXPERIENCED ANY OF THE FOLLOWING SYMPTOMS? PLEASE CIRCLE

YES OR NO AND CIRCLE IF CONSTANT OR IN EPISODES.
Yes No 1. Double vision Constant In Episodes
Yes No 2. Blurred vision Constant In Episodes
Yes No 3. Blindness Constant In Episodes
Yes No 4. Numbness of the face or extremities Constant In Episodes
Yes No 5. Weakness in the arms or legs Constant In Episodes
Yes No 6. Clumsiness of the arms or legs Constant In Episodes
Yes No 7. Confusion or loss of consciousness Constant In Episodes
Yes No 8. Difficulty with speech Constant In Episodes
Yes No 9. Difficulty with swallowing Constant In Episodes
Yes No 10. Pain in the neck or shoulders Constant In Episodes

Table 2–1E Dizziness Questionnaire—Past Medical History, Family History, Social History

Yes No 1. Did you have a history of earaches or ear infections as a child?

Yes No 2. Did you ever injure your head? When?_____________________________________
Yes No 3. Were you ever unconscious? When?______________________________________
Yes No 4. Did you suffer from motion sickness before age 12? __________________________
Yes No 5. Have you suffered from motion sickness in the last 10 years? ___________________
Yes No 6. Do you now take any medications regularly? What?__________________________
Yes No 7. Have you taken medication in the past for dizziness? Which ones?
___________________________________________________________________
___________________________________________________________________
Yes No 8. Do you have a past medical history of: Diabetes? Heart disease?
High blood pressure? Kidney disease? Thyroid disease? Migraine?
Yes No 9. Do you have a family history of: Ear disease? Neurologic disease?
Migraine headache?
Yes No 10. Do you use tobacco in any form? What kind? ___________ How much? _________
Yes No 11. Does caffeine affect your dizziness? How? _________________________________
___________________________________________________________________
Yes No 12. Does alcohol affect your dizziness? How? _________________________________

20
 CHAPTER 2: HISTORY OF THE DIZZY PATIENT 21

References
1. Blakely BW, Goebel J: The meaning of the word ‘‘vertigo.’’ Otolaryngol Head Neck Surg
125:147–150, 2001.
2. Maarsingh OR, Dros J, van Weert HC, Schellevis FG, Bindels PF, van der Horst HE:
Development of a diagnostic protocol for dizziness in elderly patients in general practice: a
Delphi procedure. BMC Fam Pract 10(1):12, 2009.
3. Jacobson GP, Newman CW: Handbook of Balance Function Testing. St. Louis: Mosby Year
Book, 1993.
3
Physical Examination of the
Dizzy Patient

Components of the Physical Examination

Physical examination of the dizzy patient should include a neurologic examination, an

otologic examination, and selected aspects of the neurotologic examination, that is, a
subset of several special examination tools.
The neurologic examination (see Table 3–1) should have the usual subcomponents:
evaluation of mental status, the cranial nerves, the motor system, sensation, coordination,
Romberg’s test, and an assessment of gait including tandem walking.
The otologic examination (see Table 3–2) should include otoscopy, preferably using an
operating microscope. Hearing should be assessed at the bedside; using a finger rub and a
tuning fork (512 Hz). The two most commonly used tuning fork tests are Weber’s test and
the Rinne test.
The neurotologic examination (see Table 3–3), which provides information regarding the
vestibulo-ocular and vestibulospinal systems, includes both routine and special components.
The routine components include (1) a search for spontaneous nystagmus; (2) bedside
(vestibulo-ocular reflex [VOR]) testing; (3) positional and positioning (Dix-Hallpike) tests
to look for persistent and paroxysmal positional nystagmus, respectively; (4) postural sway
while standing on a compliant (foam) surface; and (5) several other tests used in special
circumstances.

Ocular Motor Examination

Evaluation of the ocular motor system is essential because vestibular system abnormalities,
both peripheral and central, can alter eye movements in a characteristic fashion. Moreover,
central nervous system lesions that produce ataxia or unsteadiness may also affect various
ocular motor subsystems independent of a vestibular disorder and thus provide localizing
information.
The components of the ocular motor examination include (1) an assessment of the
alignment of the two eyes, (2) range of eye movement, (3) the presence of any instabilities
such as nystagmus or involuntary saccades, and (4) an assessment of saccades, pursuit, and
vergence. Although a complete discussion of each type of eye movement is beyond the

22
 CHAPTER 3: PHYSICAL EXAMINATION OF THE DIZZY PATIENT 23

Table 3–1 Neurologic Examination

Mental status
Cranial nerves
Motor system
Sensation
Coordination
Romberg’s test
Assessment of gait including tandem walking

Table 3–2 Otologic Examination

Otoscopy
Bedside hearing assessment
Finger rub
Weber’s test
Rinne test

Table 3–3 Neurotologic Examination

ROUTINE TESTS

Search for Spontaneous Nystagmus

Eyes open in the dark; requires use of infrared/Frenzel’s goggles
Post-Head-Shaking Nystagmus
Bedside Vestibulo-Ocular Reflex (VOR) Tests
Head thrust test
VOR ophthalmoscopy
Illegible E test
Positional Testing
Dix-Hallpike Test
Stability on a Foam Padt

SPECIAL TESTS
Pneumatic otoscopy
Cervical-Ocular Testing (Head-Fixed, Body-Turned Maneuvers)
Head Roll Test for Horizontal Semicircular Canal Benign Paroxysmal Positional Vertigo
Hyperventilation
Tragal Compression and Pneumatic Otoscopy while Observing Eye Movements
Valsalva Maneuver
Pastpointing

scope of this book, elements of the ocular motor examination will be discussed in more
detail below and as they arise in other case discussions. For an in-depth discussion of eye
movement abnormalities, the reader is referred to Leigh and Zee’s excellent work entitled
The Neurology of Eye Movements.1
Misalignment of the visual axes (i.e., strabismus) may cause complaints of double
vision, blurred vision, or vertiginous sensations. To assess patient’s ocular alignment,
begin with a general inspection with both eyes open and viewing a single target, and look
24 VESTIBULAR DISORDERS

for gross misalignment of the visual axes. Ask the patient to follow a small target such as
a penlight through the full range of movements including the nine cardinal positions of
gaze. Look for any obvious misalignment of the eyes and ask the patient whether he or
she notices any visual disturbance such as double or blurred vision in any field of gaze.
Other useful techniques for assessing ocular misalignment include the cover-uncover
test, the cross-cover test, and the Maddox rod test. These techniques are explained in
detail in other texts, for example, in Leigh and Zee’s comprehensive text.1 The finding of
an ocular misalignment may indicate a restriction or weakness of an extraocular muscle.
Patients with an obvious ocular misalignment and little or no complaint of diplopia on
testing usually have had strabismus since childhood. The finding of vertical misalign-
ment suggests the presence of a skew deviation. Skew deviation has been reported most
commonly in association with brainstem or cerebellar lesions and also can be due to
injury to the otolith organs within the inner ear. Generalized limitation of range of
movement may be a sign of myasthenia gravis. Limitation of voluntary vertical gaze
may indicate abnormality of the midbrain including neurodegenerative disorders such as
progressive supranuclear palsy, mass lesions, infarction, hemorrhage, hydrocephalus, or
encephalitis.
Ocular instabilities include nystagmus and non-nystagmus movements (See Figure 3.1).
In nystagmus, there is a slow movement in at least one direction. With jerk nystagmus,
there is a clearly defined quick and slow movement. The most common type of jerk
nystagmus is horizontal gaze-evoked nystagmus, sometimes simply called ‘‘gaze nystag-
mus.’’ in which there is a right-beating nystagmus on rightward gaze and a left-beating
nystagmus on leftward gaze (see Case 34). In pendular nystagmus there is no clearly
defined quick and slow movement. Non-nystagmoid ocular instabilities include move-
ments in both directions. Square-wave jerks are saccades away from and back to the point
of fixation. Square-wave jerks are seen commonly in older individuals and in an older
person may be considered a nonspecific finding. In younger individuals, square-wave jerks
are considered abnormal and are most often seen with anxiety or with abnormalities of the
cerebellum or brainstem. Ocular flutter and opsoclonus are rapid saccadic to-and-fro
movements of the eyes without a normal intersaccadic interval. The causes of ocular flutter
and opsoclonus include structural lesions of the pons or cerebellum, viral encephalitis, a
paraneoplastic syndrome, or a toxic agent or medication.

Horizontal Ocular Instability

Slow in One or Both Directions ?

Yes No Saccadic Fixation Instability

Slow in One Direction ?
Yes No
Square wave jerks
Jerk Nystagmus Pendular Nystagmus Ocular Flutter
Opsoclonus

Gaze-evoked Nystagmus Congenital Nystagmus

Vestibular Nystagmus Acquired Pendular Nystagmus

Figure 3.1 Horizontal ocular instability flowsheet.

 CHAPTER 3: PHYSICAL EXAMINATION OF THE DIZZY PATIENT 25

Saccadic eye movements are examined by asking the patient to fixate alternately
between two stationary targets. One target (e.g., the examiner’s nose, finger, or pen) should
be placed so that the patient can fixate upon it with the eyes in the primary position. A
second target (e.g., a finger or pen) is then positioned to produce an approximate 15-degree
saccade. Saccades can be tested in both the horizontal and vertical planes. The examiner
should assess the velocity and accuracy of the saccades. Slowing of adducting saccades
suggests brainstem dysfunction, that is, as part of internuclear ophthalmoplegia. Inaccurate
saccades point to cerebellar lesions.
Pursuit eye movements are assessed by asking the patient to carefully follow with their
eyes the examiner’s slowly moving finger. The most common abnormality observed is a
failure to adequately track the finger movement, manifested as saccadic pursuit, that is,
small saccadic eye movements interspersed with slow following movements.
During vergence eye movements, the eyes move in an opposite but coordinated fashion.
Both eyes move toward the nose to view nearby objects (i.e., convergence). Divergence
occurs as the eyes rotate outward to view more distant objects. Vergence eye movements
should be elicited by asking patients to follow their thumb or a penlight as you move it
toward and away from the bridge of the nose. Vergence movements are usually slow and
smooth. Abnormal abrupt adduction of the eyes in association with pupillary constriction
may occur during vergence, called convergence spasm (see Case 31). Another abnormality
of convergence is convergence insufficiency, wherein patients have difficulty aligning
their eyes on near targets (see Case 14). Nystagmus that is present in primary gaze may
change during vergence. For example, congenital nystagmus is typically dampened by
convergence, and central vestibular nystagmus may be exaggerated or change direction
during convergence.

Bedside Assessment of Hearing

The simplest bedside test of hearing is performed by asking patients whether they can hear
a finger rub near their left and right ears. This is equivalent to about a 30 dB stimulus at
4000 Hz. More sophisticated bedside testing of hearing use tuning forks of various
frequencies. Two commonly performed tuning fork tests are the Weber and the Rinne
tests, both typically performed using a 512 Hz tuning fork. Weber’s test is performed by
placing the vibrating tuning fork on the vertex of the head (forehead) and noting whether
the sound is heard in the midline (Weber midline), which is normal, or in one ear or the
other Weber right or Weber left), which is pathological. With unilateral disease, Weber’s
test usually lateralizes away from the ear with a sensorineural hearing loss or toward the ear
with a conductive hearing loss.
The Rinne test can be performed by first placing the stem of the vibrating tuning fork on
the subject’s mastoid bone (the bony prominence behind the pinna) and then placing the
tines of the vibrating tuning fork near the external auditory canal without touching the
patient. If the sound is perceived as louder during air conduction, which is normal, the
result is called Rinne positive. If the sound is perceived as louder during bone conduction,
which is abnormal, the result is called Rinne negative.
Weber’s test and the Rinne test are generally used together to help indicate whether an
asymmetry of hearing is present and whether the hearing loss is conductive or sensori-
neural. Used in conjunction, these tests provide valuable information about the relative
hearing between the patient’s two ears and whether a hearing loss is primarily sensorineural
or conductive. An abnormal bedside assessment of hearing should prompt audiometric
testing.
26 VESTIBULAR DISORDERS

Neurotologic Examination

All patients should undergo a routine neurotologic examination (see Table 3–3). A search
for spontaneous nystagmus should include the observation of a patient’s eyes open in the
dark using infrared glasses (Figure 3.2) or with reduced visual fixation using Frenzel’s
glasses. Nystagmus that increases in intensity or is seen only with infrared or Frenzel
glasses suggests a peripheral vestibular system imbalance. Post head-shaking nystagmus
is observed using infrared glasses following about 15 seconds of brisk to-and-fro passive
horizontal head rotation.2,3 With asymmetric central vestibular function, patients may
manifest a transitory nystagmus. Unfortunately, post head-shaking nystagmus is not a
specific test for vestibular abnormalities; that is, it has a relatively high false-positive
rate.
Bedside vestibulo-ocular reflex testing can be accomplished in three ways: (1) obser-
ving eye movements following abrupt head movements, that is, the head thrust test;4 (2)
observing the fundus of one eye with an ophthalmoscope while the other eye is occluded
during head-shaking;5 and (3) assessing visual acuity during head-shaking.6
To perform the head thrust test, grasp the patient’s head, rotate it slowly 30 degrees to
the right or left, and then briskly return the head to the center. Normally, the amount of eye
movement required to refixate a visual target immediately upon cessation of an abrupt 30
degree passive horizontal head rotation is negligible. Unilateral vestibular loss results in an
asymmetry of eye movement seen following the head thrust, that is, a refixation saccade.

Figure 3.2 Infrared video goggles. The patient’s eyes are illuminated by invisible infrared light
sources behind opague goggles. Infrared goggles eliminate visual fixation while allowing the
examiner to observe vestibular nystagmus.
With permission from Micromedical Technology.
 CHAPTER 3: PHYSICAL EXAMINATION OF THE DIZZY PATIENT 27

Bilateral vestibular loss leads to a refixation saccade following head thrusts to both the
right and the left.
To best accomplish head-shaking during ophthalmoscopy, the patient should be asked
to make high-frequency head rotations of very small amplitude. Normally, the fundus
appears fixed in space. If the fundus appears to move, either an uncompensated vestibular
loss or a bilateral vestibulopathy with decreased gain of the vestibulo-ocular reflex is
suggested.
The assessment of visual acuity during head shaking, also known as the illegible E test,
can uncover an abnormal vestibulo-ocular reflex. Loss of more than two lines of acuity on a
Snellen chart usually indicates an abnormally low vestibulo-ocular reflex magnitude.
Unfortunately, this type of testing is inexact because the head movement delivered to
each patient differs. Nonetheless, this bedside maneuver can provide useful information,
especially when used to detect a change in vestibular function by serial testing of the same
patient over time.
Positional testing is performed by observing the patient’s eyes using infrared or Frenzel
glasses while the patient assumes the supine, head left, left lateral, head right, and right
lateral positions (Figure 3.3A). The significance of persistent positional nystagmus is
uncertain. However, a direction-fixed positional nystagmus (a nystagmus that beats in

Figure 3.3 Techniques for performing positional and positioning testing. (A) Head positions for
observing persistent positional nystagmus. (B) The Dix-Hallpike test for diagnosing benign
paroxysmal positional vertigo. In the sitting position, the patient’s head is turned 45 degrees to
the right or left. Next, the patient is taken rapidly from the sitting to the supine position. The
head is then gently moved to the final head-hanging position.
Source: With permission from Baloh RW: Dizziness, Hearing Loss, and Tinnitus: The Essentials of
Neurotology. Philadelphia: FA Davis, 1984, p 81. 9
28 VESTIBULAR DISORDERS

the same direction in all positions) is more likely to be related to a peripheral vestibular
abnormality. A direction-changing positional nystagmus (a nystagmus whose direction
changes when the patient changes from one ear down to the other ear down) can be caused
by either peripheral or central vestibular lesions.
Paroxysmal positioning testing, that is, the Dix-Hallpike test, is used in diagnosing
benign paroxysmal positional vertigo, which is discussed in Cases 7, 23, 24, 25, 26, 28, and
39. The Dix-Hallpike test is performed by first turning the patient’s head 45 degrees either
to the right or to the left and then rapidly bringing the patient from the seated to the supine
position (Figure 3.3B). The patient’s eye movements should be observed once they reach
the supine head-turned position, if possible using infrared or Frenzel’s glasses. The onset of
geotropic vertical and torsional nystagmus that follows a short delay and is transitory
(typically lasting less than 30 seconds) and associated with a perception of vertigo is
diagnostic of benign paroxysmal positional vertigo.
Romberg’s test may be negative in patients with a vestibular disorder. When assessing
patients with dizziness and disequilibrium, Romberg’s test should be modified to include
the use of a compliant surface such as a foam wheelchair pad7,8 (Figure 3.4). Because
movement at the ankle is greatly diminished while the patient is standing on foam, the
somatosensory system provides an erroneous estimate of postural sway. Thus, if a patient
stands on foam with the eyes closed, only the vestibular system remains to provide accurate

Figure 3.4 Clinical foam posturography. The patient stands on a dense foam pad with the arms
folded on the chest and with the eyes open, then closed.
 CHAPTER 3: PHYSICAL EXAMINATION OF THE DIZZY PATIENT 29

information regarding orientation. The patient’s sway should be monitored during standing
on foam for evidence of excessive instablility.
Several examination tools may be used in special circumstances. Pneumatic otoscopy
allows an assessment of sensitivity of the patient to abrupt fluctuations of external auditory
canal pressure. Head-fixed, body-turned maneuvers are performed to assess the cervico-
ocular reflex by keeping the head fixed with the eyes open in the dark, thereby eliminating
visual and vestibular inputs (see Case 58). Nystagmus seen during head-fixed, body-turned
maneuvers suggests an abnormal cervico-ocular reflex and is called cervical nystagmus.
This test can be performed in both the seated and recumbent positions.
Other bedside neurotologic tests include an assessment of eye movements following
hyperventilation, during tragal stimulation, and during the Valsalva maneuver. The hyper-
ventilation test is discussed in Case 5. Tragal stimulation is performed by applying gentle
pressure on the tragus while observing the eyes for nystagmus. The Valsalva maneuver
should also be performed while observing the eyes for nystagmus. Pastpointing is per-
formed by asking the patient to extend his or her arm and point to the ceiling. Then, with the
eyes closed, the patient is asked to touch the examiner’s finger. If the patient moves in such
a way that he or she would miss the examiner’s finger, the examiner moves under the
patient’s finger and the test is abnormal. Pastpointing should not be confused with
dysmetria. Pastpointing indicates a vestibular system imbalance.

References
1. Leigh RJ, Zee DS: The Neurology of Eye Movements, ed 4. New York: Oxford University
Press, 2006.
2. Kamei T, Kornhuber H: Spontaneous and head-shaking nystagmus in normals and in patients
with central lesions. Can J Otolaryngol 3:372–380, 1974.
3. Hain TC, Fetter M, Zee DS: Head-shaking nystagmus in patients with unilateral peripheral
vestibular lesions. Am J Otolaryngol 8:36–47, 1987.
4. Halmagyi G, Curthoys I: A clinical sign of canal paresis. Arch Neurol 45:737–739, 1988.
5. Zee D: Ophthalmoscopy in examination of patients with vestibular disorders. Ann Neurol
3(4):373–374, 1978.
6. Longridge NS, Mallinson AI: A discussion of the dynamic illegible ‘‘E’’ test: A new method
of screening for aminoglycoside vestibulotoxicity. Otolaryngol Head Neck Surg 92:671–677,
1984.
7. Shumway-Cook A, Horak FB: Assessing the influence of sensory interaction of balance. Phys
Ther 66:1548–1550, 1986.
8. Weber PC, Cass SP: Clinical assessment of postural stability. Am J Otol 14(6):566–569, 1993.
9. Baloh RW: Dizziness, Hearing Loss, and Tinnitus: The Essentials of Neurotology. Philadelphia:
FA Davis, 1984.
4
Vestibular Laboratory
Testing

Vestibular laboratory testing of the dizzy patient should be reserved for those for whom
such testing may be useful in establishing a diagnosis. Laboratory testing is most useful
when a thorough history has been obtained and a physical examination has been performed
to guide both the selection of appropriate tests and the interpretation of those tests.
Vestibular laboratory testing may be helpful in distinguishing between a peripheral and a
central vestibular abnormality. Also, for disorders thought to be peripheral, vestibular
laboratory testing may enable lateralization of the abnormality, which is often helpful when
designing and monitoring therapy. Vestibular laboratory testing is also useful in allowing
documentation of an abnormality suspected as the result of a bedside evaluation. This is
particularly helpful when patients are being evaluated by several physicians and may also
be useful for medical/legal situations.
In patients who are undergoing treatment either specifically for a balance disorder or for
another condition that requires potentially ototoxic medication, vestibular laboratory
testing may be useful because it allows patients to be evaluated during their course of
treatment for vestibular abnormalities. Certain tests, such as rotational testing and postur-
ography, lend themselves more to serial evaluation than does caloric testing, which is
unpleasant for the patient.
Vestibular laboratory tests can be divided into vestibulo-ocular and vestibulospinal
tests. Each type of testing relies on a measure of motor response or output resulting from
vestibular sensory input. Because of this reliance on measuring a motor output, either eye
movements, postural sway, or muscle potentials currently available as vestibular labora-
tory tests provide only an indirect measure of vestibular end-organ function.
Vestibulo-ocular testing is well established and relies on the vestibulo-ocular reflex
(VOR). To properly evaluate the VOR, it is necessary first to assess the neural motor
output, that is, the ocular motor system, independent of the vestibular system. Because eye
movement abnormalities, if undetected, could lead to the erroneous conclusion that an
abnormality is a result of a vestibular system lesion, an ocular motor screening battery is
performed to identify difficulties with the neural control of eye movements. Vestibulo-
ocular reflex tests, which include caloric, positional, and rotational testing, are described in
the remainder of this chapter.
The vestibulospinal reflexes are not as well understood as the VOR, and to date,
vestibulospinal testing consists mostly of using a moving posture platform to record
sway. The vestibulospinal system is studied by altering vision and somatic sensation so
that patients must rely on vestibular sensation to maintain balance.

30
 CHAPTER 4: VESTIBULAR LABORATORY TESTING 31

Ocular Motor Testing

Ocular motor testing is designed to uncover abnormalities in ocular motor control in both
the rapid and slow eye-movement systems. Ocular motor testing consists of (1) a search for
nystagmus with and without visual fixation, (2) a search for gaze nystagmus with both
horizontal and vertical gaze deviation, (3) an assessment of saccadic eye movements, (4) a
recording of ocular pursuit, and (5) a recording of optokinetic nystagmus.
Video-oculography and electro-oculography are the most commonly used methods for
recording eye movements. The physiologic basis for electro-oculography is the corneal-
retinal dipole potential. This is created by the metabolic activity of the retina, which causes
the eye to act as a dipole oriented more or less outward along the visual axis.
Videoculography uses computerized digital image processing and is rapidly replacing
electro-oculography.
By convention, for horizontal recordings, upward deflections of the chart recorder pen
denote rightward eye movement and downward deflections denote leftward eye move-
ment. For vertical recordings, upward deflections denote upward eye movement and
downward deflections denote downward eye movements. An example of nystagmus
recorded with electro-oculography is shown in Figure 4.1.

Positional Testing

Positional testing is performed by placing the patient in the following positions—supine,

head left while supine, left lateral, head right while supine, and right lateral—while
recording eye movements in the dark. Positional testing is designed to search for static
positional nystagmus. Static positional nystagmus is not paroxysmal since it is present as
soon as the patient assumes the provocative position and persists as long as the patient stays
in that position. Static positional nystagmus is a nonspecific, nonlocalizing sign.
Paroxysmal positional nystagmus, that is, nystagmus induced by the Dix-Hallpike man-
euver, may have the typical characteristics of benign paroxysmal positional nystagmus; that
is, it (1) appears predominantly torsional and upbeating (that is, beating toward the forehead),

Figure 4.1 Shown diagrammatically are the two components of nystagmus: slow and fast. By
convention, for horizontal eye movements, upward deflections on the eye movement record
correspond to rightward eye movements, and downward deflections on the record correspond to
leftward eye movements. Note that the velocity of the slow component is less than the velocity
of the fast component, as evidenced by the slope of the lines representing these components of
nystagmus.
32 VESTIBULAR DISORDERS

(2) has a brief latency of 5 to 10 seconds prior to its appearance, (3) lasts for 15 to 45 seconds,
(4) is typically associated with vertigo, and (5) diminishes or disappears with repeated
provocation. Because electro-oculography and commercially available vide-oculography
systems are insensitive to torsional eye movements and vertical electro-oculography is
plagued by artifacts and a high signal-to-noise ratio, typical benign paroxysmal positional
nystagmus, which is largely torsional, is difficult to record in the vestibular laboratory.
Although there are benign variants of typical benign paroxysmal positional vertigo, if a
nystagmus is recorded during the Dix-Hallpike maneuver that does not conform in every
respect to the typical pattern seen with benign paroxysmal positional nystagmus, it should be
considered the result of a central nervous system abnormality until proven otherwise.

Caloric Testing

Caloric stimulation of the labyrinth is the mainstay of vestibular laboratory testing and forms
the basis for so-called electronystagmography. The basis for caloric testing is the establish-
ment of a thermal gradient across the horizontal semicircular canal. By positioning the
patient in such a way that the horizontal semicircular canal lies in the vertical plane, for
example, 30 degrees of head flexion from the supine, a convection current is developed that is
thought to induce a change in activity in the vestibular nerve. Although research from
microgravity (outer space) experiments has indicated that the thermal stimulus, independent
of the convection current, actually generates a portion of the caloric response, the convection
current theory still accounts for the majority of the caloric response (Figure 4.2).

Figure 4.2 Caloric testing. The physiologic basis for caloric testing is the establishment of a
thermal gradient across the horizontal semicircular canal and placement of the horizontal canal
in the vertical plane such that a convection current is developed.
Source: Adapted with permission from Baloh RW, Honrubia V (eds). Clinical Neurophysiology of the
Vestibular System, ed 2. Philadelphia: FA Davis, 1999, p 159. 5
 CHAPTER 4: VESTIBULAR LABORATORY TESTING 33

The caloric stimulus to the labyrinth can be delivered into the external auditory canal
using either water or air. Nystagmus responses induced by caloric irrigation are analyzed
by measuring the velocity of the slow component of the nystagmus, whose magnitude
reflects the intensity of the vestibular response (Figure 4.3). Many studies have shown that
the peak slow component velocity attained following caloric irrigation is the best determi-
nant of the intensity of a particular response.1
To compare the responsiveness of one ear to that of the other ear, established practice is to
use Jongkees’ formula to compute a percent reduced vestibular response. Quite simply, the
peak slow component velocities are summed for each ear and then subtracted from the sum of
responses to irrigation of the opposite ear. The difference is normalized by dividing by the
sum of the four responses and then multiplying by 100 to develop a measure of reduced
vestibular response in percent. Each vestibular laboratory should establish its own normative
values. For many laboratories, a reduced vestibular response of less than 25 is considered
within normal limits. A unilateral caloric reduction almost always signifies a peripheral
vestibular lesion, which by definition includes a lesion localized to the vestibular end organ,
the vestibular nerve, or the vestibular nerve root entry zone. Typically, the side of the
reduced vestibular response is the lesion side. Rarely, however, the lesion side may have a
hyperactive rather than a hypoactive response. In such cases, the lesion side may actually be
contralateral to the side of the caloric reduction.

-Right Cool Peak SCV: 20°/sec -Left Warm Peak SCV: 19°/sec
40 40
Slow Component Velocity (DEG/SEC)

Slow Component Velocity (DEG/SEC)

30 30

20 20

10 10

0 0

–10 –10

–20 –20

–30 –30

–40 –40
-Right Warm Peak SCV: –17°/sec -Left Cool Peak SCV: –16°/sec
0 20 40 60 80 100 120 0 20 40 60 80 100 120
SECONDS SECONDS

(20+17) – (19+16)
Reduced Vestibular Response = = 3% left
(20+17+19+16)
(20+19) – (17+16)
Directional Preponderance = = 8% left beating
(20+17+19+16)

Figure 4.3 Slow-component velocity response to caloric irrigations. Note that the peak
slow-component velocity is bracketed and that the reduced vestibular response and directional
preponderance values from Jongkees’ formula are normal.
Source: Furman JM, Cass SP: Laboratory testing. I. Electronystagmography and rotational testing. In
Baloh RW, and Halmagyi M (eds). Disorders of the Vestibular System. New York: Oxford University Press,
1996, p 201. 6
34 VESTIBULAR DISORDERS

When responses in an ear to warm and cool irrigation are absent, most laboratories use
ice-water irrigation to provoke a response. Like any alerting stimulus, ice-water irrigation
may unmask a latent spontaneous nystagmus. Thus, caloric responses induced by ice-water
irrigation should be recorded with the patient both supine (head up 30 degrees) and prone
(head down 30 degrees) in order to invert the orientation of the horizontal semicircular
canal. Only if the direction of the caloric nystagmus reverses is it certain that the ear truly
has a caloric response.
In patients with bilateral vestibular loss, caloric responses are reduced or absent in both
ears. Some patients require ice-water irrigation of both ears (sequentially) to ascertain the
overall level of unresponsiveness. However, some patients may have reduced or even
absent caloric responses and preserved rotational responses. This apparent contradiction
can be explained by understanding that caloric stimulation is a nonphysiologic but useful
laboratory curiosity, whereas rotation is the natural stimulus of the labyrinth. Also, because
thermal stimulation is gradual, caloric stimulation is comparable to a very low frequency
rotational stimulus with an equivalent frequency of about 0.003 Hz.2
Thus, some patients may respond minimally to caloric testing because of its very low
equivalent frequency, yet still have robust responses during rotational testing, which uses
much higher frequencies.3 Rarely, patients may exhibit increased caloric responses. As in
the case of increased gain on rotational testing (see below), increased responses usually
signify cerebellar disease. Also available from the caloric response is a measure of so-
called directional preponderance, which expresses numerically whether the amount of
right-beating nystagmus exceeds the amount of left-beating nystagmus or vice versa.
Unlike the measure of reduced vestibular response, the directional preponderance of
caloric testing is a nonspecific and nonlocalizing sign of vestibular dysfunction.
Moreover, the measure is more variable than the reduced vestibular response. Most
laboratories use a value of 30% directional preponderance as a threshold of normality.
The great advantage of caloric testing is that it, like the vestibular evoked myogenic
potential (VEMP), provides lateralizing information that is not available from any other
vestibular laboratory test. Disadvantages of the caloric test include its variability, its
propensity for inducing nausea and occasional vomiting, and the unwillingness of most
patients to undergo repeated caloric testing even when such testing would be helpful for
management.

Rotational Testing

Rotational testing relies on natural stimulation of the labyrinth, namely, angular accelera-
tion. Rotational testing typically uses so-called earth-vertical axis rotation, in which a
subject sits on a computer-controlled turntable and is turned left and right in a prescribed
fashion (Figure 4.4). Assessment of the VOR independent of vision is accomplished by
rotating the patient with the eyes open in the dark. Rotational testing can also be used to
assess visual–vestibular interaction by rotating patients in various visual conditions.
Unlike caloric testing, rotational testing stimulates both labyrinths simultaneously; one
is inhibited while the other is excited. Many different types of rotation can be used for
rotational testing. The most common types are sinusoids, that is, sinusoidal harmonic
acceleration. With this type of stimulus, subjects are rotated first to the right and then to
the left, then right, then left, and so on in a smooth, sinusoidally varying pattern of velocity
and acceleration. Patients may also be rotated at a constant velocity followed by an abrupt
deceleration to a stop.
 CHAPTER 4: VESTIBULAR LABORATORY TESTING 35

Figure 4.4 Earth-vertical axis rotational testing is usually performed using a test chair
located inside an enclosure with a computer-controlled turntable. Testing of the vestibulo-ocular reflex
(VOR) is performed with the eyes open in darkness or occluded with opaque goggles.
Courtesy of Neurokinetics.

To analyze the nystagmus induced by rotational testing, it is necessary to identify the

slow components, because these reflect the influence of vestibular stimulation. The slow
components induced by rotational stimulation are pieced together to generate a so-called
cumulative slow-component eye position. This response measure is typically differentiated
mathematically to yield the slow-component eye velocity, which can be compared with the
turntable velocity to establish the response parameters of gain, phase, and symmetry
(directional preponderance).
The gain of the nystagmus response to sinusoidal earth-vertical axis rotation is, by
definition, the ratio of the magnitude of the response to the magnitude of the stimulus. The
estimate of gain is obtained by using a computer to fit the best sinusoid through the slow-
component eye velocity and then by dividing the magnitude of that best fit by the peak
velocity of the sinusoidal rotational stimulus.
Reduced gain indicates decreased vestibular sensitivity. Unilateral vestibular loss may
or may not reduce gain below normal. Thus, reduced gain usually indicates bilateral
vestibular loss. Rarely, gain can be abnormally large, usually as a result of a cerebellar
lesion.
The phase of the response to sinusoidal earth-vertical axis rotation is also determined
following generation of the best-fit sinusoid through the slow-component eye velocity
response. Phase represents the timing relationship between the eye velocity response and
turntable velocity. Phase is a highly sensitive but nonspecific measure of vestibular system
36 VESTIBULAR DISORDERS

function. Phase commonly changes with peripheral vestibular injury, and the changes are
often permanent. Another measure, comparable to phase, can be obtained from constant
velocity rather than sinusoidal rotations. That measure, the so-called time constant of the
VOR, is a measure of how rapidly the vestibular nystagmus decays following an abrupt
stop of the rotational chair. Like phase, the VOR time constant is a sensitive but nonspecific
measure of vestibular system abnormality.
Many patients, especially those who are symptomatic at the time of testing, display an
asymmetric response, that is, a directional preponderance (Figure 4.5). Despite a sym-
metric stimulus with equal rotations to the right and to the left, patients with a directional
preponderance display an excessive amount of either right-beating or left-beating nystag-
mus. Such an asymmetry of response can manifest simply as a shift in the average velocity
of the response, or the slow-component velocity may have a nonsinusoidal shape with a
higher velocity in one direction or the other. A rotational response asymmetry indicates an
ongoing vestibulo-ocular imbalance but does not provide localizing information.
Another type of rotational testing, visual–vestibular interaction, which is usually reserved
for detailed testing of patients suspected of having a central vestibular lesion, is performed by
asking patients to look at a small target that rotates with them or by having them view earth-
fixed full-field stripes or dots while undergoing earth-vertical axis rotation. In this way,
vision is used to either reduce or augment the vestibular response, respectively. Visual–
vestibular interaction testing is particularly useful when assessing central vestibular abnorm-
alities because appropriately combining visual and vestibular information depends upon the
normal functioning of brainstem and cerebellar structures. Typically, patients are rotated at a
single sinusoidal frequency (1) with eyes open in the dark, (2) with a fixation target, and
(3) with earth-fixed stripes. A sinusoidal optokinetic stimulus while the patient is stationary

Figure 4.5 A recording of horizontal (top trace) and vertical (middle trace) eye position during
earth-vertical axis rotation. The recording uses the standard convention of upward pen
deflection indicating a rightward or an upward movement. The record shows a horizontal
nystagmus in the horizontal recording and eye-blink artifacts in the vertical recording. The
lowest trace indicates turntable velocity, which in this case is varying sinusoidally at 0.05 Hz.
Note that in this patient, who is abnormal, there is much more right-beating nystagmus than
left-beating nystagmus.
 CHAPTER 4: VESTIBULAR LABORATORY TESTING 37

may be used as a pure visual stimulus. The responses to these visual, vestibular, and
combined visual–vestibular stimuli are recorded and analyzed in a manner similar to the
response to sinusoidal rotational acceleration in the dark, that is, to yield gain and phase.
Rotational testing has several advantages: (1) the stimulus can be controlled precisely;
(2) rotation consists of the natural stimulation of the labyrinth, that is, angular acceleration;
(3) rotation is rarely bothersome; (4) rotation can be used for serial evaluations; and (5) in
special circumstances, visual–vestibular interaction can be assessed. Testing can be per-
formed at several rotational frequencies and amplitudes, allowing flexibility in the design
of the stimulus so that patients with particular types of abnormalities, such as bilateral
vestibular loss, can be evaluated more thoroughly. In particular, higher frequencies and
amplitudes of rotation can be used to determine the degree, if any, of remaining vestibular
function in patients who have suffered bilateral vestibular loss either from ototoxic
medication or from an underlying disease state.4 The great disadvantage of rotational
testing is that it does not provide lateralizing information since both labyrinths are
stimulated simultaneously. Thus, rotational testing is best used as an adjunct to caloric
testing.

Posturography

Posturography is now performed in many vestibular laboratories using the commercially

available EquiTest device. Testing is divided into two broad types, which have been named
motor control (formerly movement coordination) testing and sensory organization testing.
Motor control testing employs repeated translations and rotations of the support surface
that are designed to assess a patient’s ability to maintain balance.
The sensory organization test is designed to manipulate vision and somatic sensation,
which constitute two of the three sensory modalities important in maintaining upright
balance. Using a technique called sway referencing, the platform and/or the visual sur-
roundings are rotated in the same way that the patient is swaying, thereby distorting these
sensory inputs. Sway referencing the platform and visual surroundings in various combi-
nations can force patients to rely primarily on their vestibular system to maintain upright
balance. Thus, the sensory organization portion of the posturography evaluation includes
six conditions, illustrated in Figure 4.6.
Figure 4.7 shows an example of the computer analysis of postural sway provided by
the EquiTest device. This patient was able to stand during the first four sensory condi-
tions as evidenced by the height of the dark bar being in the white area but was unable to
stand during the fifth and sixth conditions; the patient lost balance. This patient therefore
has a vestibular pattern on posturography suggesting an ongoing vestibulospinal abnorm-
ality. Another pattern of abnormality, shown in Figure 4.8, is called a surface-dependent
pattern and suggests a combined visual and vestibular abnormality regarding postural
control. Only when provided with reliable proprioceptive input can such an individual
stand.
An advantage of dynamic posturography is that it evaluates upright balance and thus
provides a functional evaluation that depends on vestibulospinal function. In this regard,
dynamic posturography provides information distinctly different from that provided by
caloric and rotational testing, which assess vestibulo-ocular responses. Dynamic posturo-
graphy is noninvasive and has been shown to be repeatable. Although a lack of patient
cooperation and effort will lead to abnormal responses, only with great sophistication can
particular patterns of abnormalities be spuriously produced.
38 VESTIBULAR DISORDERS

Figure 4.6 The sensory organization portion of computerized dynamic posturography includes
six paradigms: (1) eyes open, platform stable; (2) eyes closed, platform stable; (3) eyes open
with visual surroundings moving and platform stable; (4) eyes open, platform moving; (5) eyes
closed, platform moving; and (6) both visual surroundings and platform moving. The
movements of the visual surroundings, the platform, or both are designed to parallel movements
of the patient’s center of mass, the so-called sway referencing, thereby providing distorted
visual or proprioceptive input. The fifth and sixth conditions, wherein the patient’s eyes are
closed or the patient is viewing moving visual surroundings while the floor moves, require the
patient to rely on the vestibulospinal system to maintain balance.
Source: With permission from NeuroCom International Inc., Clackamas, Oregon.

Figure 4.7 Shows an example of the computer analysis of postural sway provided by the
EquiTest device. This patient was able to stand during the first four sensory conditions as
evidenced by the height of the dark bar being in the white area but unable to stand on the fifth and
sixth conditions; the patient lost balance. This patient therefore has a vestibular pattern on
posturography, suggesting an ongoing vestibulospinal abnormality.

A disadvantage of dynamic posturography is that the results are nonspecific and

nonlocalizing and may indicate vestibular disease even when not present. Also, older
adults without vestibulospinal abnormalities may fall on computerized dynamic posturo-
graphy. Computerized dynamic posturography also can be used to record changes in
postural stability.
 CHAPTER 4: VESTIBULAR LABORATORY TESTING 39

Figure 4.8 Computer analysis of postural sway provided by the EquiTest device for a patient
who was able to stand during the first three sensory conditions but unable to stand on the fourth,
fifth, and sixth conditions. This patient has a surface-dependent pattern on posturography,
suggesting a combined visual/vestibular abnormality regarding postural control. Such an
individual can stand only with reliable proprioceptive input.

Vestibular Evoked Myogenic potentials

Vestibular evoked myogenic potentials (VEMPs) refer to electrical activity recorded from
neck muscles in response to intense auditory clicks.6-11 VEMPs reflect stimulation of the
sacculus unilaterally and thus provide information about the integrity of the sacculus and
the inferior vestibular nerve. There are no other tests available that are known to assess
either the sacculus or the inferior vestibular nerve in isolation. Several studies have shown
reduced or absent VEMPs in individuals with known peripheral vestibular loss. Moreover,
VEMP magnitudes have been found to be elevated and thresholds reduced in semicircular
canal dehiscence syndrome. A limitations of VEMPs is the technical challenge of obtaining
an electromyographic recording from a pre-activated muscle that has the appropriate
amount of background activity. Another limitation of VEMPs is that they rely on normal
middle ear function when performed using air-conducted stimuli, which is most common.
VEMPs using bone conducted stimuli and ocular VEMPs are currently being developed.12

References
1. Jacobson GP, Newman CW: Handbook of Balance Function Testing. St. Louis: Mosby Year
Book, 1993.
2. Hamid M, Hughes G, Kinney S: Criteria for diagnosing bilateral vestibular dysfunction. In:
Graham MD, Kemink JL (eds). The Vestibular System: Neurophysiologic and Clinical
Research. New York: Raven Press, 1987, pp 115–118.
3. Furman JM, Kamerer DB: Rotational responses in patients with bilateral caloric reduction.
Acta Otolaryngol (Stockh) 108:355–361, 1989.
4. Baloh RW, Honrubia V, Yee RD, Hess K: Changes in the human vestibulo-ocular reflex after
loss of peripheral sensitivity. Ann Neurol 16:222–228, 1984.
5. Baloh RW, Honrubia V: Clinical Neurophysiology of the Vestibular System, ed 2.
Philadelphia: FA Davis, 1999.
6. Colebatch JG, Halmagyi GM: Vestibular evoked potentials in human neck muscles before and
after unilateral vestibular deafferentation. Neurology 42:1635–1636, 1992.
40 VESTIBULAR DISORDERS

7. Robertson DD, Ireland DJ: Vestibular evoked myogenic potentials. J Otolaryngol 24:3–8,
1995.
8. Matsuzaki M, Murofushi T, Mizuno M: Vestibular evoked myogenic potentials in patients
with acoustic neuromas. Arch Otolaryngol Head Neck Surg 124:509–512, 1998.
9. Ferber-Viart C, Dubreuil C, Duclaux R: Vestibular evoked myogenic potentials in humans: A
review. Acta Otolaryngol (Stockh) 119:6–15, 1999.
10. Heide G, Freitag S, Wollenberg I, Iro H, Schimrigk K, Dillman U: Click evoked myogenic
potentials in the differential diagnosis of acute vertigo. J Neurol Neuorsurg Psychiatry
66:787–790, 1999.
11. Murofusko T, Matsuzaki M, Wu CH: Short tone burst-evoked myogenic potentials on the
sternocleidomastoid muscle. Arch Otolaryngol Head Neck Surg 125:660–664, 1999.
12. Iwasaki S, Smulders YE, Burgess AM, McGarvie LA, Macdougall HG, Curthoys IS: Ocular
vestibular evoked myogenic potentils to bone conduct the midline forehead at Fz in healthy
subjects. Clin Neurophysiol 119(9):2135–2147, 2008.
5
Auditory System and Testing

The cochlea, the human organ of hearing, consists of a membranous structure called the
cochlear duct, which is approximately 33 mm in length and twisted into a spiral with two and
three-quarter turns (Figure 5.1). The cochlear duct is supported by a bony skeleton consisting
of a central modiolus and a surrounding otic capsule. The afferent auditory neuronal cell
bodies form the spiral ganglion, which is located inside the modiolus of the cochlea. The
spiral arrangement of the cochlear duct results in a spiral arrangement of neurons within the
spiral ganglion. The auditory nerve, which is a component of the eighth cranial nerve, carries
approximately 30,000 primary afferent neurons and about 1,000 efferent nerve fibers, whose
function is unknown. Because the vestibular and auditory apparatus share common inner ear
fluids, nerves, blood supply, and location within the temporal bone, disorders that affect the
peripheral vestibular apparatus often affect hearing. Vertigo associated with a unilateral
hearing loss suggests a peripheral vestibular abnormality on the side with the hearing loss.
Thus, it is important to assess hearing in the evaluation of the dizzy patient because hearing
loss may help to localize a vestibular system disorder to the labyrinth and also may help to
lateralize the problem to a particular ear.
Many vertigo syndromes have characteristic associated audiologic findings that can
help establish a specific diagnosis. For example, a fluctuating low-frequency sensor-
ineural hearing loss is characteristic of endolymphatic hydrops, that is, Meniere’s
disease. Acute vestibular neuritis is characterized by the absence of auditory symptoms
and normal hearing. Compression of the vestibular-cochlear nerve within the internal
auditory canal or cerebellopontine angle by a neoplasm can produce symptoms of
unsteadiness and disequilibrium as well as a sensorineural hearing loss, which typically
presents at high frequencies and is slowly progressive. Such lesions also cause dimin-
ished word recognition. Otosclerosis, which may cause dizziness, produces a character-
istic conductive hearing loss.

Laboratory Assessment of Hearing

Audiogram and Word Recognition Test

The mainstay of hearing assessment consists of two psychophysical tests: the pure-tone
audiogram and the word recognition test.1,2 The pure-tone audiogram summarizes hearing
thresholds compared to those of normal persons at standardized pure-tone frequencies that
range from 250 to 8000 Hz. These hearing thresholds are plotted in a graphic format,

41
42 VESTIBULAR DISORDERS

Figure 5.1 Two views of the anatomy of the cochlea. The left panel shows the three turns of the
cochlear duct. The cochlear nerve enters the center of the cochlea from the internal auditory
canal. The right panel shows one turn of the cochlea in greater detail. The organ of Corti
contains the hair cells involved in transduction of sound to neural activity.
Source: With permission from Silverstein H, Wolfson RJ, Rosenberg S: Diagnosis and management of
hearing loss. Clin Symp 44(3):5, 1992. 10

wherein the abscissa (horizontal axis) is frequency and the ordinate (vertical axis) is
hearing threshold in decibels (dB) referenced to the sound pressure level of normal hearing
at each test frequency (Figure 5.2). The word recognition test measures the ability of a
patient to repeat correctly words represented at 30 to 40 dB louder than the patient’s
hearing threshold. The percentage of words correctly recognized is reported for each ear
separately.
Normally, hearing thresholds are symmetric in the two ears. When one ear is found to
have significantly worse hearing than the other ear, further evaluation of the auditory
system is warranted, especially to rule out eighth nerve or cerebellopontine angle lesions.
Although there are no strict guidelines as to when to pursue further evaluation of asym-
metric hearing loss, a significant hearing difference is considered to be 10 dB or more at
two adjacent test frequencies or a 15% or greater difference in word recognition scores. It is
recommended that whenever a significant hearing asymmetry is present that cannot be
explained by other clinical circumstances, such as unilateral noise-induced hearing loss,
either brainstem auditory-evoked potential testing (see later) or brain imaging be per-
formed to rule out a structural lesion of the auditory system.3

Tympanometry and Acoustic Reflex Testing

Tympanometry and acoustic reflex testing are commonly used audiologic screening tests.4
Tympanometry assesses the compliance (acoustic resistance) of the tympanic membrane
 CHAPTER 5: AUDITORY SYSTEM AND TESTING 43

Figure 5.2 Audiogram.

and middle ear ossicles and is largely used to help diagnose middle ear infection.
Tympanometry is also used as part of the electronystagmographic perilymphatic fistula
test. This test consists of changing external auditory canal pressure while recording eye
movements. Patients with a perilymphatic fistula may develop nystagmus or eye deviation
in response to pressure changes. Acoustic reflex testing assesses the integrity of the
stapedius reflex by exposing the ear to loud sound and then assessing changes in acoustic
resistance; thus, it provides information about the afferent sensory (auditory) and efferent
motor (facial nerve) limbs of this reflex. Historically, acoustic reflex testing has been used
as part of a site-of-lesion test battery. However, more advanced audiologic tests (see
below), such as brainstem auditory-evoked potential testing and electrocochleography,
have superseded acoustic reflex testing and other previously used site-of-lesion tests for
localizing disorders of the auditory system.

Brainstem Auditory-Evoked Potential Testing

Brainstem auditory-evoked potential testing is an electrophysiologic test used to evaluate

the integrity of the auditory pathway from the cochlea through several brainstem auditory
relay centers.5 In the brainstem auditory-evoked potential testing procedure, auditory
clicks or brief tone bursts are delivered through headphones to evoke a highly synchronous
and repeatable neural response. This response is measured using surface electrodes and
standard signal averaging techniques. The evoked neural potentials that occur early, that is,
within 1 to 12 milliseconds, reflect cochlear nerve and brainstem activity and are collec-
tively called brainstem auditory-evoked potentials or the auditory brainstem response. The
brainstem auditory-evoked potential is characterized by a series of five vertex-positive
44 VESTIBULAR DISORDERS

Figure 5.3 Analysis of brainstem auditory-evoked potentials (BAEP). Latency measurements

are used more commonly than amplitude measurements. Absolute latencies, relative latencies,
and interaural latencies (not shown) can be used in the analysis and interpretation of BAEP.

waves (I to V) that are thought to correspond to relay centers within the auditory pathway:
wave I—cochlear nerve at the level of the spiral ganglion; wave II—cochlear nerve/
brainstem junction; wave III—cochlear nucleus; wave IV—superior olive complex;
wave V—lateral lemniscus; and waves VI and VII—inferior colliculus. The interpretation
of the brainstem auditory-evoked potential is based on the qualitative morphology of the
waveforms and the quantitative latency and amplitude of each wave.
Brainstem auditory-evoked potential testing can be used for site-of-lesion testing since
the latencies of waves I to V can be compared between the two ears and to normative data6,7
(Figure 5.3). These measurements can be used to determine whether abnormal wave
latencies exist and the likely anatomic site of such delays. Disruption of auditory neural
transduction may be caused by neoplasia, by compression or invasion of the eighth cranial
nerve or brainstem, or by demyelination anywhere along the central auditory pathway.
Auditory system abnormalities may be associated with concomitant vestibular abnormal-
ities caused by the close anatomic relationship between the vestibular nerve and the
auditory nerve and between the vestibular nuclei and the cochlear nuclei. Thus, brainstem
auditory-evoked potential testing, which provides information regarding the integrity of
central auditory pathways, also provides information regarding central vestibular path-
ways. Brainstem auditory-evoked potential testing can also be used for determining
auditory thresholds in patients who cannot otherwise cooperate, such as adults with altered
mental status and infants.

Electrocochleography

Electrocochleography is a modification of the brainstem auditory-evoked potential test in

which wave I is amplified to reveal both the action potential of the cochlear nerve, also
called N1, and another wave preceding the action potential is referred to as the summating
potential. Normally, the ratio of the summating potential to the action potential is less than
1:3. However, when endolymphatic hydrops is present, the summating potential increases
relative to the action potential (Figure 5.4). When the ratio of summating potential to action
potential amplitude exceeds 0.5, it is considered abnormal and indicative of endolymphatic
 CHAPTER 5: AUDITORY SYSTEM AND TESTING 45

Figure 5.4 The SP/AP ratio is calculated by measuring the amplitudes of the summating
potential (SP) and action potential (AP, labeled N1 in the figure) from baseline (0).
Source: With permission from Campbell K, Harker AL, Abbas PJ: Interpretation of electrocochleography
in Meniere’s disease and normal subjects. Ann Otol Rhinolaryngol 101: 497, 1992.11

hydrops. The association of an elevated summating potential/action potential ratio with

endolymphatic hydrops has been substantiated both experimentally and clinically.8,9 Thus,
electrocochleography can be helpful in diagnosing endolymphatic hydrops as the under-
lying cause of a balance disorder.
Electrocochleography is particularly useful in patients whose symptoms are not char-
acteristic of a particular disorder. Also, in cases in which both ears appear to be affected,
electrocochleography may be helpful in localizing underlying endolymphatic hydrops to
an actively pathological ear.

References
1. Katz J (ed): Handbook of Clinical Audiology. Baltimore: Williams & Wilkins, 1994.
2. Rintelmann WF (ed): Hearing Assessment. Perspectives in Audiology Series. Austin: Pro-Ed,
1991.
3. Selesnick SH, Jackler RK: A typical hearing loss in acoustic neuroma patients. Laryngoscope
103:437–446, 1993.
4. Sheehy JL, Hughes RL: The ABC’s of impedance audiometry. Laryngoscope 134(11):
1935–1949, 1974.
5. Moller AR: Audiotory neurophysiology. J Clin Neurophysiol 11(3):284–308, 1994.
6. Selters WA, Brackmann DE: Acoustic tumor detection with brain stem electric response
audiometry. Arch Otolaryngol 103:181–187, 1977.
7. Wilson DF, Hodgson RS, Gustafson MF, Hogue S, Mills L: The sensitivity of audiotory
brainstem response testing in small acoustic neuromas. Laryngoscope 102:961–964, 1992.
8. Ferraro JA, Arenberg K, Hassanein S: Electrocochleography and symptoms of inner ear
dysfunction. Arch Otolaryngol 111:71–74, 1985.
9. Arenberg IK, Ackley RS, Ferraro J, Muchnik C: EcoG results in perilymphatic fistula: Clinical
and experimental studies. Otolaryngol Head Neck Surg 99(5):435–443, 1988.
10. Silverstein H, Wolfson RJ, Rosenberg S: Diagnosis and management of hearing loss. Clin
Symp 44(3):5, 1992.
11. Campbell K, Harker AL, Abbas PJ: Interpretation of electrocochleography in Meniere’s
disease and normal subjects. Ann Otol Rhinol Laryngol 101:497, 1992.
6
Vestibular Rehabilitation

Physical therapy evaluation and treatment have become an important resource in the
management of the dizzy patient. In the 1940s, Cawthorne,1 Cooksey,2 and later, Dix and
Hood3 recognized that patients who actively moved their heads recovered more quickly
and completely from acute peripheral vestibular lesions than those who did not. These
early clinical observations led to numerous experimental and clinical studies that have
supported the concept that vestibular exercises promote functional balance recovery and
compensation following vestibular system injury. More recently, the writings of
Shumway-Cook and Horak4 and Herdman5 have focused the expertise of therapists on
the problem of functional recovery following vestibular system injury. A customized
exercise program improves the quality of the outcome after physical therapy interven-
tion. The formerly common practice of dispensing a generic list of head movement
exercises has evolved into a referral for a comprehensive sensory and motor evaluation
by a skilled physical therapist with specialized training in balance disorders who then
develops a treatment plan for a program of vestibular rehabilitation. There is evidence
that a customized exercise program improves function faster than a generic treatment
program.6,7 The goal of vestibular rehabilitation is to develop a specific program of
movements/exercises directed at improving a patient’s functional balance deficits,
decreasing the risk of falling, decreasing dizziness, increasing activity level, and improv-
ing functional abilities.
Who is a candidate for vestibular rehabilitation? Patients who typically respond favor-
ably to vestibular rehabilitation include those with nonfluctuating peripheral vestibular
loss, chronic uncompensated peripheral vestibulopathy, post-surgical acoustic schwan-
noma, multisensory disequilibrium, drug-induced vestibulopathy, head trauma, migraine-
related vestibulopathy, cervical dizziness, stroke (anterior inferior and posterior inferior
cerebellar arteries), panic/anxiety disorders, and the vestibular imbalance that follows a
destructive surgical procedure. Patients with episodic vertigo who have otherwise normal
balance (e.g., many patients with Meniere’s disease) are not candidates for therapy because
exercises do not influence the frequency or severity of episodes. There is some benefit of
counseling people with Meniere’s disease on how to compensate and deal with their
dizziness symptoms. Patients with benign paroxysmal positional vertigo do not typically
require vestibular rehabilitation unless their evaluation uncovers evidence for an ongoing
vestibulo-ocular or vestibulospinal imbalance. However, there is recent evidence that
persons with benign paroxysmal positional vertigo may experience balance dysfunction
for at least 1 month after resolution of their benign paroxysmal positional vertigo.8 Therapy
is indicated for these selected patients, especially those at risk for falling.

46
 CHAPTER 6: VESTIBULAR REHABILITATION 47

Despite the fact that some balance disorders are easier to treat than others and that
some disorders have poorer prognoses than others, vestibular rehabilitation has few
contraindications. The therapist should be informed of the patient’s medical problems
and diagnoses, results of vestibular testing, medications, and contraindicated exercises
such as vigorous neck exercises in patients with vertebral vascular disease. Patients
should be reassured that they must often be willing to ‘‘feel worse before they begin to
feel better.’’ Patients with post-concussion syndrome and those with migraine-related
dizziness must be carefully managed; experiencing significant increases in dizziness is
not in their best interest for optimal recovery. A very measured increase in activity will
maximize their chance of recovery. There is no age limit for a trial of vestibular
rehabilitation. 9

Theoretic Basis for Physical Therapy

Although considered primarily reflexive, vestibular responses are actually quite malleable.
The ability to alter the vestibulo-ocular reflex (VOR) forms one of the theoretic bases for
vestibular rehabilitation. Physiologic alterations of the VOR can be brought about by (1)
changing the magnitude of the VOR using an altered visual environment such as that
produced by magnifying or miniaturizing lenses;10 (2) changing the timing of the VOR
using repeated rotations;11, 12 and (3) altering vestibulo-ocular responses by imagining an
earth-fixed or a head-fixed visual target.13 This capacity for vestibulo-ocular responses to
change, depending on the demands of the situation, provides the therapist with a modifiable
substrate. In addition, there is some preliminary evidence that the saccadic eye movement
system ‘‘helps’’ to keep objects in focus if there is damage to the VOR.
As discussed in Chapter 1, following a peripheral vestibular injury, the vestibular
system is known to alter its properties to produce a more functional response. Unilateral
vestibular injury is known to be followed immediately by an acute vestibular syndrome.
However, in a matter of hours or days, depending on the patient’s age and central nervous
system status, the symptoms of acute vestibular loss abate so that the patient can perform
the activities of daily living. This process of central nervous system compensation for
unilateral peripheral injury occurs by mechanisms as yet unknown. However, certain types
of movement and exposure to visual surroundings enhance this compensation process,
especially for dynamic reflexes.14 Also, certain pharmaceutic agents (e.g., meclizine) may
slow this process.15 Neurophysiologically, the response to unilateral peripheral vestibular
injury undoubtedly includes changes in the neural activity in the vestibular nuclei. The
crossed pathways of the vestibular commissures may be important for the compensatory
process.16 After compensation, if a subsequent injury occurs to the contralateral vestibular
system, some individuals appear to have an acute vestibular injury only on the newly
affected side. Bilateral peripheral vestibular injury is a more challenging problem than
unilateral vestibular injury. Proprioceptive and visual influences assume a more important
role in stabilization of the eyes and the body following severe bilateral vestibular deficits.
The therapist can exploit this process during vestibular rehabilitation.7

Technique of Vestibular Rehabilitation

A thorough discussion of the technique of vestibular rehabilitation is beyond the scope of

this book. However, a brief overview follows. For an in-depth discussion of this topic, the
reader is referred to the excellent textbook by Herdman entitled Vestibular Rehabilitation.5
48 VESTIBULAR DISORDERS

Vestibular Rehabilitation Assessment

A thorough evaluation of each patient by the therapist on an individualized basis

precedes the development of a treatment plan for vestibular rehabilitation. This
evaluation begins by reviewing material supplied by the referring physician,
which typically includes the diagnosis/differential diagnosis and medical history
including medications, recently prescribed medications, and laboratory test
results. Even though a diagnostic evaluation by the referring physician has
already been undertaken, the therapist personally evaluates the patient’s vestibu-
lar, proprioceptive, and visual systems from his or her own perspective to uncover
any deficits that may be affecting the patient’s balance. The patient’s height,
weight, cognitive function, attentional capacity, vision, strength, posture, coordi-
nation, presence of joint pain, and range of motion can all affect balance and are
thus evaluated as well. Because some patients are able to balance without diffi-
culty if they are in an environment with little extraneous movement but have
marked problems in more dynamic environments that contain extraneous move-
ment, the patient should be evaluated in different settings if possible. The thera-
pist must obtain a history of the patient’s problem, with an emphasis on his or her
functional deficits. This may include a Dizziness Handicap Inventory 17 to assess
the patient’s perception of handicap at each visit. The Dizziness Handicap
Inventory attempts to quantify the effects of dizziness on a patient’s function,
physical status, and emotional well-being. The activities-specific balance confi-
dence scale, another self-report measure, can be used to quantify balance con-
fidence with each visit. 18
The therapist then elicits a detailed social history to determine whether the patient
is living in a safe environment. The therapist may make recommendations that attempt
to improve the level of safety in the patient’s home environment. For example, it may
be suggested that a patient use a night light in the bedroom, remove throw rugs, or
install handrails. It is also helpful to know whether any family members can assist the
patient in a home exercise program. Then the therapist performs a physical examina-
tion to assess the patient’s ability to perform functional movements with the eyes
open, eyes closed, and at various speeds. Transitional movements that are tested
include rolling, sitting, reaching, standing, and the Dix-Hallpike test (see Chapter 3
and Case 7). Then the therapist assesses head and eye movements. This assessment
parallels that of the physical examination performed by the physician. However, the
patient’s symptoms, such as dizziness and blurred vision, are especially important
during these movements. The therapist then assesses sensation and the patient’s ability
to sit, stand, and walk in different situations. Static balance measures include Romberg
testing, single leg stance, and tandem Romberg testing. Following the elicitation of a
history and the performance of a physical examination, the therapist may perform a
functional balance assessment (Table 6–1). The functional balance assessment is a tool
box that the physical therapist uses to determine function in persons with vestibular
disorders or those who are at risk of falling. All of the tools except the Physical
Performance Test, have been validated with persons with vestibular disorders. Use of
the tools permits subjective and objective comparisons of the patients’ perceived
status and assists in determining whether the patient is improving. Several findings
determined while making the rehabilitation diagnosis should suggest contacting the
physician immediately.
 CHAPTER 6: VESTIBULAR REHABILITATION 49

Table 6–1 Functional Balance Assessment

Test Type of Data Scale

19
Dynamic Gait Index Ordinal 0–24 (24 is the best score)
Timed ‘‘Up & Go’’20 Ratio 0 to as much time as
required (lower scores are best)
Clinical Test of Sensory Integration Ratio if timed 0–30 seconds (30 seconds is best)
and Balance (CTSIB)21
Berg Balance Scale22 Ordinal 0–56 (56 is the best score)
Modified Gait Abnormality Ordinal
Rating Scale23
Physical Performance Test24 Ordinal 0–36 points (36 is the best score)
Functional reach25 Length 0 inches to as long as the
person can reach (higher scores best)
Gait speed26 Velocity 0 to whatever speed is achieved
(higher scores are best)
Five times sit to stand test27,28 Time 0 to as long as is required
(shorter is best)

Vestibular Rehabilitation Interventions

Herdman5 recommends that therapists identify the specific problems and functional
limitations of each patient so that a list of vestibular rehabilitation goals can be constructed.
Once these goals are established, the therapist has numerous movements from which to
choose to develop a program for each patient. Many of these movements can be performed
by the patient at home. They are designed to potentiate compensation for peripheral
vestibular lesions and to help patients learn how to substitute other sensory inputs, such
as vision and somatosensory inputs, for vestibular sensation. Substitution of other sensory
modalities is especially important in patients with bilateral vestibular deficits.
Herdman5 states that ‘‘The goals of physical therapy intervention are to improve the patient’s
mobility, overall general physical condition and activity level, functional balance, safety for gait
and gait-related activities, and the magnitude of the patient’s symptoms.’’ Because many
patients’ symptoms worsen in the early stages of vestibular rehabilitation, vestibular suppres-
sants may be prescribed when therapy begins if necessary. Subsequently, these medications,
which may actually impair vestibular compensation, should be discontinued as soon as possible.
Table 6–2 lists balance and gait exercises often used at the University of Pittsburgh
Medical Center. Table 6–3 lists the general principles for helping patients make progress in
their rehabilitation.
Patients with bilateral vestibular reduction generally have a more serious balance problem
and a worse prognosis than those with unilateral vestibular loss. Many of the principles that
underlie the vestibular rehabilitation of patients with unilateral vestibular loss also apply to
patients with bilateral vestibular loss, but there are several special considerations: recovery is
slower; sensory substitution is the primary means of rehabilitation; exercises may be needed
chronically; visual input (proper lighting) is critical; and a cane or walker may provide a great
deal of help, especially early in the rehabilitation process.5 After assessment and development
of a treatment plan, patients are typically seen in follow-up every week for a total of six to
eight visits so that progress can be monitored and the treatment program modified as needed.
Factors that affect the outcome of vestibular rehabilitation are listed in Table 6–4. Note that
Table 6–2 Balance and Gait Exercises

1. Perform the following exercises while standing. Stand near a kitchen counter, but hold on only if
needed.
a. Walk sideways 15 ft. Repeat in both left and right directions ______ times, twice a day.
b. Walk backward 15 ft. Repeat ______ times, twice a day.
2. Perform the following exercises while standing. Stand with a wall behind you. Have a family
member stand nearby if needed. Stand on a pillow or couch cushion for ______ seconds.
a. Do this with your eyes open. Repeat ______ times, twice a day.
b. Do this with your eyes closed. Repeat ______ times, twice a day.
c. Stand on one leg with your eyes closed. Repeat ______ times, twice a day.
3. Walk down a corridor and practice moving your head left and right. Keep your head turned in
either direction for about three steps. Walk ______ ft. Repeat ______ times, twice a day. Also
repeat by moving your head up and down.
4. Set up an obstacle course. Use chairs, pillows, and furniture as obstacles. Place smaller objects on
the floor that you must step over. Change the course each time so that you do not get used to the
same routine.
You can incorporate stair climbing, sitting to standing, or picking up and carrying objects during
the obstacle course. Set a timer or clock yourself to see how quickly you can finish.
To add difficulty, have a family member give commands (e.g., ‘‘Turn left now’’) or throw a ball
toward you unexpectedly.
5. Walk around a darkened room (preferably carpeted) in your house for ______ minutes.
6. Go grocery shopping as tolerated.
7. Do your walking program at a shopping mall one or two times a week.

Source: Adapted from Herdman SJ (ed). Vestibular Rehabilitation. Philadelphia: FA Davis, 2000, p. 404.5

Table 6–3 General Principles for Progression in Vestibular Rehabilitation

Slow to fast movement

Wide to narrow base of support
Reaching inside to outside the base of support
Eyes open to eyes closed
Stable support surface to compliant support surface
Vary environmental constraints
Eye movement with no head movement to eye movement with coordinated head movement
Walking with head stable on trunk to walking with head moving on trunk

Table 6–4 Factors That Affect the Outcome of Vestibular Rehabilitation

Abnormalities of strength or range of motion

Age
Combined central and peripheral vestibular disorders
Duration and chronicity of illness
Medical comorbidities such as diabetes, kidney disease, or liver disease
Migraine
Neck dysfunction
Ongoing litigation
Peripheral neuropathy
Preexisting eye movement disorders such as strabismus or amblyopia
Preexisting or associated psychiatric disorders
Preexisting orthopedic conditions

50
 CHAPTER 6: VESTIBULAR REHABILITATION 51

the patients least likely to benefit include those with fluctuating conditions, those with pure
central nervous system disorders, those with mixed central and peripheral disorders, and those
involved in litigation.

References
1. Cawthorne TE: Vestibular injuries. Proc R Soc Med 39:270–273, 1945.
2. Cooksey FS: Rehabilitation in vestibular injuries. Proc R Soc Med 39:275, 1945.
3. Dix MR, Hood JD: Vestibular habituation: Its clinical significance and relationship to
vestibular neuronitis. Laryngoscope 80:226–232, 1970.
4. Shumway-Cook A, Horak FB: Rehabilitation strategies for patients with vestibular deficits.
In: Arenberg IK (ed). Dizziness and Balance Disorders. New York: Kugler, 1993,
pp 667–691.
5. Herdman SJ (ed): Vestibular Rehabilitation, ed 3. Philadelphia: FA Davis, 2007.
6. Shepard NT, Telian SA. Programmatic vestibular rehabilitation. Otolaryngol Head Neck Surg
112:173–182, 1995.
7. Krebs DE, Gill-Body KM, Riley PO, Parker SW. Double-blind, placebo-controlled trial of
rehabilitation for bilateral vestibular hypofunction: Preliminary report. Otolaryngol Head
Neck Surg 109(4):735–741, 1993.
8. Di Girolamo S, Paludetti G, Briglia G, Cosenza A, Santarelli R, Di Nardo W. Postural control
in benign paroxysmal positional vertigo before and after recovery. Acta Otolaryngol
118(3):289–293, 1998.
9. Cohen HS, Kimball KT: Increased independence and decreased vertigo after vestibular
rehabilitation. Otolaryngol Head Neck Surg 128(1):60–70, 2003.
10. Melvill Jones, G: Adaptive modulation of VOR parameters by vision. In: Berthoz, A, Melvill
Jones G (eds). Adaptive Mechanisms in Gaze Control: Reviews in Oculomotor Research.
Amsterdam: Elsevier, 1985, pp 21–50.
11. Schmid R, Jeannerod M: Vestibular habituation: An adaptive process? In: Berthoz A, Melvill
Jones G (eds). Adaptive Mechanisms in Gaze Control. Amsterdam: Elsevier, 1985,
pp 113–122.
12. Baloh RW, Henn V, Jager J: Habituation of the human vestibulo-ocular reflex by low
frequency harmonic acceleration. Am J Otolaryngol 3:235, 1982.
13. Melvill Jones G, Berthoz A: Mental control of the adaptive process. In: Berthoz, A, and
Melvill Jones G (eds). Adaptive Mechanisms in Gaze Control. Amsterdam: Elsevier, 1985,
pp 203–212.
14. Igarashi M: Physical exercise and acceleration of vestibular compensation. In: Lacour M et al
(eds). Vestibular Compensation. Amsterdam: Elsevier, 1989, pp 131–144.
15. Peppard SB: Effect of drug therapy on compensation from vestibular injury. Laryngoscope
96:878–898, 1986.
16. Bienhold H, Flohr H: Role of commissural connexions between vestibular nuclei in
compensation following unilateral labyrinthectomy. J Physiol 284:178, 1978.
17. Jacobson GP, Newman CW: The development of the Dizziness Handicap Inventory. Arch
Otolaryngol Head Neck Surg 116:424–427, 1990.
18. Powell LE, Myers AM: The activities-specific balance confidence (abc scale). J Gerontol Med
Sci 50(1):M28–M34, 1995.
19. Shumway-Cook A, Woollacott M: Motor Control: Theory and Practical Applications.
Baltimore: Williams & Wilkins, 1995.
20. Podsiadlo D, Richardson S: The timed ‘‘up & go’’: A test of basic functional mobility for frail
elderly persons. JAGS 39:142–148, 1991.
21. Shumway-Cook A, Horak FB: Assessing influence of sensory interaction on balance. Phys
Ther 66:1548–1550, 1986.
22. Berg KO, Wood-Dauphinee SL, Williams JI, Maki B: Measuring balance in the elderly:
Validation of an instrument. Can J Public Health 83:S7–S11, 1992.
52 VESTIBULAR DISORDERS

23. VanSwearingen JM, Paschal KA, Bonino P, Yang JF. The modified Gait Abnormality Rating
Scale for recognizing the risk of recurrent falls in community-dwelling elderly adults. Phys
Ther 76(9):994–1002, 1996.
24. Reuben DB, Siu AL: An objective measure of physical function of elderly outpatients. JAGS
38:1105–1112, 1990.
25. Duncan P, Weiner D, Chandler J, Studenski S: Functional reach: A new clinical measure of
balance. J Gerontol 45:M192–M197, 1990.
26. Cerny K: Clinical method of quantitative gait analysis. Phys Ther 63:1125–1126, 1983.
27. Nevitt MC, Cummings SR, Kidd S, Black D: Risk factors for recurrent nonsyncopal falls. A
prospective study. JAMA 261(18):2663–2668, 1989.
28. Meretta BM, Whitney SL, Marchetti GF, Sparto PJ, Muirhead RJ: The five times sit to stand
test: Responsiveness to change and concurrent validity in adults undergoing vestibular
rehabilitation. J Vestib Res 16(4–5):233–243.
7
Psychiatric Aspects of
Vestibular Disorders

It is common practice to assign a single diagnosis to a patient with dizziness. This strategy
is usually appropriate, though in some cases two or more neurotologic disorders may
present simultaneously. For dizzy patients with psychiatric disorders, it is generally
inappropriate to assign a single diagnosis, that is, to consider a patient’s dizziness as arising
from either a neurotologic disorder or a psychiatric disorder. The ‘‘either-or, but not both’’
approach usually leads to suboptimal care. Typically, neurotologic disorders and psychia-
tric disorders coexist and interact. It is common practice to regard a patient’s description of
his or her dizziness as an indication of the origin of the problem. That is, spinning of the
outside world has been thought to indicate a vestibular disorder, whereas spinning in the
head has been thought to indicate a psychiatric disorder. Unfortunately, such inferences are
not uniformly accurate. Thus, when evaluating a patient with dizziness, it is best to regard
psychiatric symptoms as a comorbidity rather than a complete explanation for all of the
patient’s symptoms.

Overlap Between Vestibular Disorders and Psychiatric Disorders

The interrelationship between vestibular disorders and psychiatric disorders is complex.

This chapter aims to provide a brief background to this topic. Figure 7.1 provides a
framework for classifying patients with a chief complaint of dizziness. The central area
indicates patients with well-defined neurotologic syndromes such as benign paroxysmal
positional vertigo, Meniere’s disease, and vestibular neuritis. The area just above it
represents patients who have a balance system disorder that cannot be assigned a specific
diagnosis. Rather, such patients have examination or laboratory abnormalities that suggest
a balance system disorder, but the etiology is uncertain. Diagnostic labels given to such
patients include vestibulopathy of unknown cause. The area above this one represents that
group of dizzy patients whose symptoms are highly suggestive of a balance disorder but
who have no objective findings to substantiate even a provisional neurotologic diagnosis.
The top area represents dizzy patients with normal vestibular function such as individuals
with orthostatic hypotension.
Patients with dizziness, with or without a vestibular abnormality, may also manifest
psychiatric disorders such as anxiety.1 Thus, superimposed on the areas that classify
vestibular disorders is the broad category of psychiatric disorders. That is, as illustrated

53
54 VESTIBULAR DISORDERS

Figure 7.1 Framework for a taxonomy of dizziness. This Venn-type diagram illustrates the
overlap between neurotologic and psychiatric etiologies for dizziness. Note that dizzy patients
can manifest a neurotologic (balance) disorder, a psychiatric disorder, or both. Moreover,
because of the difficulty in establishing a neurotologic diagnosis definitively, there are
subgroups of patients with subclinical balance disorders, nonsyndromal balance disorders, and
those with a well-defined neurotologic syndrome. A contemporaneous psychiatric disorder can
be seen with all groups.

diagrammatically in Figure 7.1, a patient may have a psychiatric disorder that coexists with
any of the four categories of dizziness. Thus, the presence of a psychiatric disorder does not
rule out a balance disorder. In fact, as noted below, some psychiatric disorders are clearly
associated with a higher likelihood of an associated vestibular disorder. So, patients with
dizziness may have a balance disorder, a psychiatric disorder, both, or neither. This scheme
helps to clarify how patients with both a vestibular disorder and a psychiatric disorder can
be categorized. However, this scheme does not provide any details regarding the type or
manner of interaction between the two types of disorders.

Interaction Between Vestibular Disorders and Psychiatric

Disorders

Figure 7.2 presents a framework for understanding the interface between psychiatric
disorders and vestibular disorders. The categories illustrated in this figure can be used to
classify dizzy patients who present with psychiatric disorders in isolation or in association
with a vestibular disorder. Category A represents individuals whose dizziness can be
explained by their psychiatric disorder alone, that is, patients with psychiatric dizziness.2
The term psychiatric dizziness should be reserved for those patients in whom the dizziness
(1) is part of a recognized psychiatric syndrome (e.g., the dizziness during a panic attack or
the abnormal gait of conversion hysteria) and (2) cannot be explained by vestibular
dysfunction. Thus, dizziness occurring during a panic attack should be labeled psychiatric
dizziness, whereas dizziness between panic attacks should not. Category B represents
individuals with a balance disorder alone, that is, without an associated psychiatric
disorder.
 CHAPTER 7: PSYCHIATRIC ASPECTS OF VESTIBULAR DISORDERS 55

Psychiatric Balance
Disorder Disorder

A B

Figure 7.2 Framework for the interface between balance disorders and psychiatric disorders.
This interface is depicted as several levels of interaction ranging from noncoexistent disorders
to a complete overlap in pathophysiology. (A) (B) Balance disorder without a psychiatric
disorder. (C) Co-occurrence of a psychiatric disorder that does not provoke dizziness and a
balance disorder with no functional overlap. (D) Co-occurrence of psychiatric dizziness and a
balance disorder with no functional overlap. (E) Psychiatric overlay. (F) Behavioral/
psychological mediation. (G) Neurological linkage.

Categories C and D represent individuals with no functional overlap between a vestib-

ular disorder and a psychiatric disorder, that is, nonfunctionally related, independently
occurring disorders.
Category E represents individuals with psychiatric overlay, in which a patient’s person-
ality or psychiatric disorder influences his or her perception of the dizziness and the way
the patient presents to and interacts with the medical profession. This category includes the
role of coping behaviors, which may influence both physiologic and psychological aspects
of the patient’s problem.
Category F represents a complex blend of mutual influences of psychiatric disorders and
vestibular disorders on one another. This category, termed psychological/behavioral
mediation, implies a causal relationship between vestibular disorders and psychiatric
disorders. That is, a vestibular disorder may cause, trigger, or exacerbate a psychiatric
abnormality (somatopsychic mechanism) or a psychiatric disorder may cause, trigger, or
exacerbate a vestibular abnormality (psychosomatic mechanism).
56 VESTIBULAR DISORDERS

Category G represents individuals in whom a vestibular disorder and a psychiatric

disorder are manifestations of a common underlying disorder. This circumstance, called
linkage, may pertain to some patients with anxiety disorders. The linkage concept is that
vestibular disorders and psychiatric disorders may be two different manifestations of a
common underlying central nervous system abnormality. Balaban and Thayer3 have
postulated that the linkage between vestibular disorders and anxiety disorders may be
based upon shared brain pathways that mediate autonomic responses. Central nervous
system structures that may be critical for this linkage include the parabrachial nucleus and
its connections with other structures. The vestibular disorder–anxiety disorder linkage also
may be based on the effects of neurotransmitters, such as the monoamines noradrenaline
and serotonin.

Somatopsychic Mechanisms

Somatopsychic mechanisms refer to psychological, psychiatric, and behavioral conse-

quences of vestibular dysfunction. One possible consequence of vestibular dysfunction is
anxiety. Anxiety has two components, somatic symptoms and cognitive symptoms.
Somatic anxiety includes heart palpitations, nausea, diaphoresis, feeling hot or cold,
shortness of breath, chest discomfort, dizziness, numbness or tingling, and feeling
detached. Cognitive anxiety includes anxious thoughts such as ‘‘What if I have a life-
threatening illness?’’ There are several different types of anxiety disorders. The Diagnostic
Manual of the American Psychiatric Association (DSM-IV)4 lists 11 different anxiety
disorders; two of these are Panic Disorder without Agoraphobia and Panic Disorder with
Agoraphobia. These disorders seem to have a particularly strong association with vestib-
ular disorders.5 The anxiety associated with vestibular dysfunction also has two compo-
nents, one related to the somatic component and the other associated with the cognitive
component.
Dizziness is often situation-specific. For example, rolling over in bed can trigger benign
paroxysmal positional vertigo. Similarly, because the balance system receives input from
three sensory systems, that is, the visual system, the somatosensory system, and the
vestibular system, situations that are characterized by inconsistencies among visual,
vestibular, and somatosensory signals can lead to dizziness even in normal individuals.
Such situations may be particularly bothersome to patients with vestibular disorders. Such
patients may show unusual sensitivity to, or need for, visual and/or somatosensory infor-
mation to maintain balance. This heightened awareness of nonvestibular sensation is called
space and motion sensitivity.6 A subgroup of these patients experience space and motion
discomfort, that is, these sensory stimuli are unpleasant. A subgroup of these individuals
may actually avoid environments with inadequate or misleading balance information such
as shopping malls or grocery stores. It is tempting to label patients who avoid such
environments as having psychogenic dizziness. In fact, such patients are likely to have
vestibular dysfunction.5 Space and motion sensitivity and space and motion discomfort
may help explain why some patients with vestibular disorders avoid certain environments.
In some patients with vestibular disorders, space and motion discomfort may interfere with
social, occupational, or academic functioning.
Other psychiatric disorders that can be induced or exacerbated by vestibular dysfunction
include depression and social withdrawal. Depressed patients pay attention to depressing
things. Thus, a depressed patient with dizziness may focus selectively on those symptoms
that remain even after partially successful treatment has been instituted. Dizziness and
imbalance also can cause social withdrawal since patients may be afraid of appearing
 CHAPTER 7: PSYCHIATRIC ASPECTS OF VESTIBULAR DISORDERS 57

drunk. Social withdrawal can also be a result of a patient adopting the sick role, that is,
behaving as one would expect someone to act if he or she were sick.
Some patients with dizziness become angry with the health care delivery system. Jacob
et al.7 suggest that dizzy patients may trigger a clinician’s dismissive behaviors, which
include a failure on the part of the physician to recognize that there is a problem, a
physician minimizing the impact of the problem, the patient’s perception that the time
spent by the physician is inadequate, and offense to the patient when the physician suggests
that the patient’s problem might be ‘‘mental.’’
Not every patient with dizziness develops a psychiatric disorder. Why? Possibly, preex-
isting anxiety, somatization, that is, the tendency to report and be preoccupied with medical
symptoms from varied organ systems, perfectionist traits, and obsessive-compulsive person-
ality disorder predispose patients to develop a psychiatric problem as a result of dizziness.7

Psychosomatic Mechanisms

Psychosomatic mechanisms refer to the alteration in vestibular function that may result
from psychiatric conditions. For example, the gain of the VOR decreases with somnolence
and increases with arousal. Therefore, increased anxiety may affect vestibular function.
Similarly, hyperventilation may affect vestibular responses.8 Psychosomatic mechanisms
also may be important in patients who have compensated for a peripheral vestibular
disorder and then have become symptomatic because of a psychiatric-induced reemer-
gence of vestibular symptoms.

Treatment Implications

What are the treatment implications for patients with combined vestibular and psychiatric
disorders? Such patients should be treated for both their vestibular and psychiatric dis-
orders. Treatment considerations include pharmacotherapy, behavioral therapy, and ves-
tibular rehabilitation.9 The presence of a vestibular disorder should not preclude the
appropriate psychiatric treatment. Similarly, the presence of a psychiatric disorder should
not preclude appropriate treatment for a patient’s balance disorder. In some patients, the
same treatment may be helpful for both disorders.

References

1. Staab JP: Chronic dizziness: The interface between psychiatry and neuro-otology. Curr Opin
Neurol 19(1):41–48, 2006.
2. Furman JM, Jacob RG: Psychiatric dizziness. Neurology 48:1161–1166, 1997.
3. Balaban CD, Thayer JF: Neurological bases for balance-anxiety links. J Anxiety Disorders
15:53–79, 2001.
4. American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders,
ed 4. Washington, DC: American Psychiatric Association, 1994.
5. Jacob RG, Furman JM, Durrant JD, Turner SM: Panic, agoraphobia, and vestibular
dysfunction. Am J Psychiatry 153:503–512, 1996.
6. Jacob RG, Woody SR, Clark DB, Lilienfeld SO, Hirsch BE, Kucera GD, Furman JM, Durrant
JD: Discomfort with space and motion: A possible marker of vestibular dysfunction assessed
by the Situational Characteristics Questionnaire. J Psycopathol Behav Assess 15:299–324,
1993.
58 VESTIBULAR DISORDERS

7. Jacob RG, Furman JM, Cass SP: Psychological sequelae of vestibule disorders. In: Luxon LM,
Martini A, Furman JM, Stephens D (eds). Textbook of Audiological Medicine. London: Martin
Dunitz Ltd. (in press).
8. Theunissen EJ, Huygen PL, Folgering HT: Vestibular hyperactivity and hyperventilation.
Clin Otolaryngol 111:161–169, 1986.
9. Jacob RG, Whitney SW, Detweiler-Shostak G, Furman JM: Vestibular rehabilitation for
patients with agoraphobia and vestibular dysfunction: A pilot study. J Anxiety Disorders
15(1–2):131–146, 2001.
8
Medications Commonly
Used to Treat Vestibular
Disorders

Medications are often required in the management of patients who present with vestibular
disorders. Medications for patients with dizziness and disequilibrium fall into two broad
categories. Some medications are disease-specific, for example, diuretics for Meniere’s
disease; other medications are used for symptomatic relief, for example, vestibular sup-
pressants and anti-nausea agents for both specific and nonspecific disorders. The choice of
medication will of course depend upon the patient’s diagnosis. Additionally, the choice
of medication will depend upon the other medications that the patient is taking because
of potential medication interactions. Also, it is important to recall that all medications have
intended effects and unwarranted (side) effects. This chapter includes a discussion of
neurotransmitters known to be important for vestibular pathways and a discussion
of vestibular suppressants, anti-nausea agents, and anti-anxiety agents. The chapter also
includes some material regarding complementary and alternative therapies. Then, disease-
specific agents will be described. Finally, mention will be made of the role of the physical
therapist in the pharmacotherapy of the patient with a vestibular disorder.
Several neurotransmitters are known to play a role in vestibular pathways, some in the
peripheral vestibular system, and some in the central vestibular system.1 Glutamate is
known to be an excitatory neurotransmitter in the peripheral vestibular system, that is, the
synapse between the vestibular hair cells and the vestibular afferents. Acetylcholine also
acts as an excitatory neurotransmitter in both the peripheral and central vestibular system
though peripherally at the efferent rather than the afferent synapse. Other neurotransmitters
important in the central vestibular system include GABA and glycine as inhibitory
neurotransmitters and dopamine as an excitatory neurotransmitter. Serotonin and norepi-
nephrine are neuromodulators. The role of histamine is uncertain. All of the nonspecific
pharmaceutical agents and some of the specific agents affect these neurotransmitters but
exactly how they do so is unknown.
Vestibular suppressants (see Table 8–1) and anti-nausea agents (see Table 8–2) generally
overlap although some medications, such as meclizine and dimenhydrinate are considered
primarily vestibular suppressants whereas other medications such as promethazine and
compazine are primarily anti-nausea agents. Vestibular suppressants are especially useful
in the acute stages of a vestibulopathy such as in the early stage of vestibular neuritis (see
Cases 1 and 3) and during attacks of Meniere’s disease (see Cases 9, 12, 20, 24, and 42) and

59
60 VESTIBULAR DISORDERS

Table 8–1 Vestibular Suppressant Medications

Drug (brand name) Pharmacologic Class Dose Adverse Reactions

Meclizine Antihistamine, 12.5–50 mg q 4–6 h orally Sedation

(AntivertTM, anticholinergic
BonnineTM)
Dimenhydrinate Antihistamine 50 mg q 4–6 h Sedation
(DramamineTM) Anticholinergic orally
Promethazine Phenothiazine 25 mg q 6–12 h Extrapyramidal
(PhenegranTM) orally or reactions,
rectally drowsiness,
restlessness
Clonazepam Benzodiazepine 0.25–0.5 mg BID Mild sedation,
(KlonipinTM) orally drug dependency
Diazepam Benzodiazepine 1–2 mg BID; 2–10 mg Sedation,
(ValiumTM) (1 dose) given respiratory
acutely orally, depression, drug
IM or IV dependency
Lorazepam Benzodiazepine 0.25–0.5 mg BID Mildly sedating,
(AtivanTM) orally drug dependency

migraine-related dizziness (Cases 8, 20, 22, and 23). Two vestibular suppressants, meclizine
and dimenhydrinate, are available over the counter although meclizine also is available by
prescription. These agents are relatively mild and are not generally useful for severe
vestibular-related symptoms of dizziness and nausea. For moderate to severe symptoms,
stronger agents such as promethazine or a benzodiazepine are usually required. For short
duration attacks of dizziness such as those associated with benign paroxysmal positional
vertigo, vestibular suppressants are not helpful because they are not preventative and do not
act quickly enough. Caveats regarding the use of vestibular suppressants include side effects
of lethargy and imbalance, and if prescribed for more than several days, impairment of
vestibular compensation. Another caveat is that some patients are prescribed transdermal
scopolamine, which has its primary use for motion sickness reduction during sea-going
cruises. Unfortunately, scopolamine can actually worsen dizziness, can cause blurred vision
and thus worsen balance, and can be difficult to stop because of withdrawal symptoms.
Medications for nausea are most helpful during acute vestibular symptoms, often in the
same circumstances in which vestibular suppressants are helpful. Note that there is a large
overlap between the medications for nausea and those for vestibular suppression, but there
are several anti-nausea agents that are narrower in their effects. Notably prochlorperazine
and trimethobenzamine fall into this category. Benadryl also can be used as an anti-nausea
agent, as can atarax. Caveats for anti-nausea agents usually include drowsiness and thus are
generally prescribed only for episodic vestibular dysfunction.
Table 8–3 lists medications used to treat anxiety associated with dizziness. As with
medication for nausea, anti-anxiety medication often overlaps with vestibular suppres-
sants. The choice of whether to prescribe any of these agents and which agents to prescribe
will depend upon which medications the patient is already taking and the patient’s
symptoms. Anti-anxiety agents are particularly helpful for patients with a history of panic
attacks or generalized anxiety. The agents can also be helpful for patients whose anxiety
limits their ability to perform routine activities or to perform balance exercises prescribed
by a therapist.
 CHAPTER 8: MEDICATIONS COMMONLY USED TO TREAT VESTIBULAR DISORDERS 61

Table 8–2 Medications Commonly Used to Reduce Dizziness and Associated Nausea

Drug Pharmacologic Dose Primary Adverse

(brand name) Class Use Reactions

Meclizine Anticholinergic 25 mg q 4–6 h Dizziness Drowsiness

(AntivertTM, Antihistamine orally
BonineTM)
Dimenhydrinate Anticholinergic 50 mg q 4–6 h Dizziness Drowsiness
(DramamineTM) Antihistamine orally
Cyclizine Anticholinergic 50 mg q 4–6 h Dizziness Drowsiness
(MarezineTM) Antihistamine orally or IM
Diazepam Benzodiazepine 1–2 mg BID Dizziness Lethargy
(ValiumTM) orally; 2–10 mg
(1 dose) given
acutely orally,
IM or IV
Clonazepam Benzodiazepine 0.25–0.5 mg Dizziness Lethargy
(KlonopinTM) BID orally
Prochlorperazine Phenothiazine 10 mg orally or Nausea Extrapyramidal
(CompazineTM) IM q 6 hours reactions,
or 25 mg rectally drowsiness,
every 12 hours anticholinergic
effects
Promethazine Phenothiazine 25 mg q 6–12 h Nausea Extrapyramidal
(PhenerganTM) orally or rectally reactions,
drowsiness,
restlessness
Trimethobenzamine Substituted 250 mg q 6–8 h Nausea Extrapyramidal
(TiganTM) ethanolamine or 200 mg reaction
rectally or IM (unusual)
Diphenhydramine Antihistamine 25–100 mg q 8 h Nausea Drowsiness
(BenadrylTM) orally
Hydroxyzine Piperazine 25–50 mg q 8 h Nausea Drowsiness
(AtaraxTM, derivative orally
VistarilTM)

Disease-specific medications are discussed in the individual case studies pertaining to

each disorder but will be reviewed briefly here. Meniere’s disease in usually treated with a
combination of hydrochlorothiazide and triamterene. The dosage is either hydrochlor-
othiazide 25 mg plus triamterene 37.5 mg each morning or twice that. Patients should be
warned that they may experience increased urination while using a diuretic. Common side
effects include leg cramps. Note that many patients with hypertension may already be
taking a diuretic either as a separate medication or a combination with another anti-
hypertensive medication; these patients’ anti-hypertensive regimen may need to be altered
in collaboration with the patient’s primary care physician. Migraine-related dizziness is
treated with a combination of medications and the drug of choice will depend on many
factors. Also, if a patient does not benefit from a particular medication or cannot tolerate a
particular medication, there are several choices of anti-migrainous agents. Vestibular
neuritis is treated with a combination of corticosteroids, vestibular suppressants, and
62 VESTIBULAR DISORDERS

Table 8–3 Medications for Anxiety Associated with Dizziness

Drug Pharmacologic Dose Adverse

(brand name) Class Reactions

Diazepam Benzodiazepine 2–5 mg daily in Lethargy

(ValiumTM) divided doses
orally
Clonazepam Benzodiazepine 0.25–0.5 mg Lethargy
(KlonipinTM) BID orally
Chlordiazepoxide Benzodiazepine 5–10 mg q Drowsiness
(LibriumTM) 6–8 h orally
Hydroxyzine Piperazine 25–50 mg q 8 h Drowsiness,
(VistarilTM, orally dry mouth
AtaraxTM)
Imipramine Tricyclic 10–100 mg Anticholinergic,
(ImavateTM, antidepressant aily orally drowsiness
JanimineTM,
PresamineTM,
SK-PramineTM,
TofranilTM)
Amitriptyline Tricyclic 10–100 mg Anticholinergic,
(AmitrilTM, antidepressant daily orally drowsiness
ElavilTM,
EndepTM)
Sertraline Selective seroto- 25–100 mg Headache,
(ZoloftTM) nin reuptake daily orally insomnia
inhibitor

anti-nausea agents. Vestibular suppressants may be required for several weeks but should
be used on an as-needed basis or discontinued whenever possible.
The role of the physical therapist in the pharmacotherapy of patients with vestibular and
balance disorders is enumerated in Table 8–4. Physical therapists often have the opportu-
nity to interact with patients frequently during their illness and may be able to assist in fact
finding and monitoring the patient’s response to both physical therapy and pharmacother-
apy. Since medication type and dosage may require adjustment over time, the patient’s
physical therapist and physician should work collaboratively. There is literature suggesting
that combining physical therapy and pharmacotherapy yields better results than either
modality alone.2

Table 8–4 Role of the Physical Therapist Regarding Medications

Fact finder
Patient advocate
Coordinate care with the prescribing physician
Adjustments of medications
Change dosage or timing
Change medication
Discontinue drug
 CHAPTER 8: MEDICATIONS COMMONLY USED TO TREAT VESTIBULAR DISORDERS 63

Some patients may wish to discuss complementary and alternative medicine regarding
their dizziness. It is important to identify which, if any, of these treatment modalities a
patient is using. Also, as some of these treatments become more ‘‘mainstream’’ based on
new literature, they should be considered treatment alternatives. Complementary and
alternative medicine is defined as an unrelated group of nonorthodox therapeutic practices,
often with explanatory systems that do not follow conventional biomedical explanations.
Complementary and alternative therapies include, but are not limited to, the following
disciplines: folk medicine, herbal medicine, homeopathy, faith healing, new age healing,
chiropractic, acupuncture, naturopathy, massage, and music therapy. The list of practices
that are considered complementary and alternative medicine changes continually as com-
plementary and alternative medicinal practices and therapies that are proven safe and
effective become accepted as mainstream health-care practices.
The National Institutes of Health currently recognizes five categories of complementary
and alternative medical practices: (1) alternative medical systems, (2) mind–body inter-
ventions, (3) biologically based treatments, (4) manipulative and body-based methods, and
(5) energy therapies. Examples include Oriental medicine, Ayurvedic medicine, medita-
tion, hypnosis, herbal therapy, orthomolecular therapy, manipulative therapy, massage
therapy, therapeutic touch, and unconventional uses of electromagnetic fields. Many types
of complementary and alternative therapies have been advocated for patients with dizzi-
ness (see Table 8–5). The usefulness of these treatments for dizziness is uncertain. This is
not surprising since once a treatment becomes recognized, it is no longer viewed as
complementary or alternative. Some complementary and alternative therapies, especially
herbal remedies, may be hazardous or may interact with conventional therapies in
unknown ways, so it is important to be aware of them.

Table 8–5 Complementary and Alternative Therapies

Complementary and Alternative Therapies Advocated for Patients With Dizziness*

Acupuncture3
Acupressure/electroacupressure bands
Nutritional therapy (vitamins, minerals, trace elements)
Herbal remedies
Ginger4
Ginko biloba
Peppermint
St. John’s wort
Vertigoheel
Oto-Vite
T-Bio
Colored lenses
Vision therapy
Aroma therapy
Magnets
Crystals
Massage therapy
Therapeutic touch

*Note that this is a partial list and that the inclusion of any of the therapies in this table does not indicate the authors’ endorsement
of the therapy.
64 VESTIBULAR DISORDERS

References
1. Hain TC, Yacovino D: Pharmacologic treatment of persons with dizziness. Neurol Clin
23(3):831–853, 2005.
2. Johnson CD: Medical management of migraine-related dizziness and vertigo. Laryngoscope
108(85 Suppl):1–28, 1988.
3. Yoo SS, The EK, Blinder RA, Jolesz FA: Modulation of cerebellar activities by acupuncture
stimulation: Evidence from fMRI study. Neuroimage 22(2):932–940, 2004.
4. Chrubasik S, Pittler MH, Roufogalis BD: Zingiberis rhizoma: A comprehensive review on the
ginger effect and efficacy profiles. Phytomedicine 12(9):684–701, 2005.
Part II

Tutorial Case Studies

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Case 1
Unilateral Vestibular
Impairment and Vestibular
Compensation—Vestibular
Neuritis

History

A 25-year-old woman who worked as a registered nurse presented with the chief complaint
of acute vertigo that began 3 days before evaluation. The patient’s vertigo was associated
with nausea and vomiting for several hours. Following this episode, the patient had
disequilibrium, gait instability, and a complaint of poor vision for 2 days. She had no
associated complaints of hearing loss or tinnitus and no fullness or stuffiness in the ears.
There were no complaints of changes in strength or sensation. The patient had experienced
a flu-like illness that had begun approximately 2 weeks before the onset of the vertigo. At
the time of evaluation, she noticed imbalance in the dark and felt disoriented, especially
after large head movements. She had no significant past medical history, and the family
history was noncontributory.
Question 1: Based on the patient’s history, what is the most likely diagnosis?
Answer 1: This patient’s history is consistent with an acute vestibular syndrome
characterized by vertigo, nausea, vomiting, blurred vision, and disequilibrium. The
absence of auditory symptoms and the prior flu-like illness suggest the possibility of
vestibular neuritis. Other, less likely conditions include endolymphatic hydrops,
migraine-related dizziness, a cerebrovascular accident, and a demyelinating disorder.
The absence of other otologic symptoms argues against endolymphatic hydrops (see
Case 9). Migraine-related dizziness (see Cases 8 and 20) or a CVA (Cases 37 and 38)
are unlikely. The absence of nonvestibular neurologic symptoms and the absence of
previous neurologic deficits make a demyelinating lesion very unlikely (see Case 30).

Physical Examination

Neurologic examination revealed a left-beating horizontal-torsional nystagmus on

leftward gaze with the upper poles of the eyes beating to the left. The patient’s nystagmus

67
68 VESTIBULAR DISORDERS

increased during gaze toward the left and decreased during gaze toward the right. The
remainder of the cranial nerve examination was normal. Strength, sensation, and coordina-
tion were normal. The patient had a negative Romberg’s test. Gait was wide-based, and the
patient could not tandem walk. The otologic examination was normal. The neurotologic
examination was abnormal. Behind infrared goggles, the patient’s nystagmus increased in
intensity; it was now observed in the primary position, and both the frequency and amplitude
of the nystagmus were higher. The head thrust test was abnormal, with refixation saccades
noted following head rotation from left to right. The patient was unable to stand on a
compliant foam surface with her eyes closed without losing her balance. Pastpointing was
present with arm deviation to the right.
Question 2: What is the pathophysiology of the patient’s symptoms and signs?
Answer 2: The patient is suffering from an acute peripheral vestibular syndrome
almost certainly caused by an acute, profound imbalance between the afferent
activity from the left and right labyrinths. Because a large difference in neural
activity normally occurs only during large head movements, the central nervous
system interprets an acute loss of vestibular activity on one side as the head rotating
briskly toward the intact ear. Patients thus experience vertigo. Vegetative
symptoms of nausea, vomiting, and diaphoresis result from activity in the pathways
from the vestibular system to the autonomic nervous system.
Question 3: What is the significance of the patient’s nystagmus being horizontal-torsional?
Answer 3: The patient’s nystagmus is caused by the imbalance in afferent activity
from the left and right labyrinths and is probably a result of imbalanced semicir-
cular canal activity rather than imbalance of otolith activity. Because of the
orientation of the three semicircular canal pairs, the afferent activity from the
intact ear, if unopposed by activity in the affected ear, combines to produce a slow
component of nystagmus whose direction has specific characteristics. Acivity
from the unopposed left horizontal semicircular canal drives the eyes horizontally
toward the right, and the combined activity of the two left vertical semicircular
canals, that is, the left superior and left posterior semicircular canals, causes a slow
torsional movement of the eyes, with the upper poles moving toward the right.
No vertical component is produced because the left superior semicircular canal
tends to drive the eyes up, while the left posterior semicircular canal tends to drive
the eyes down, thereby canceling the vertical influences. Thus, the predominantly
horizontal-torsional nystagmus suggests a net effect of three unopposed semicir-
cular canals of the patient’s left ear combining to produce a nystagmus whose
slow component has a horizontal direction toward the lesioned ear and whose
quick component (for which the nystagmus direction is named) beats horizontally
toward the intact ear.
Question 4: Why did the patient’s nystagmus increase during gaze toward the left and
decrease during gaze toward the right?
Answer 4: The alterations in the patient’s nystagmus as a function of eye position in
the orbit are typical of most types of nystagmus wherein the intensity of the
nystagmus, including its frequency and amplitude, increases when a patient looks
in the direction of the quick component. This phenomenon, whereby the magni-
tude of the nystagmus changes as a function of eye position, is known as Alexander’s
law1,2 and is illustrated in Case 1: Figure 1. The physiologic basis for Alexander’s law
may relate to an alteration in the neural integrator leading to a combined effect of a
 CASE 1: UNILATERAL VESTIBULAR IMPAIRMENT AND VESTIBULAR COMPENSATION 69

Case 1: Figure 1 Alexander’s system of grading vestibular nystagmus. Note that only the
horizontal quick components of nystagmus are illustrated for the nine standard positions of gaze
with the head motionless. The length and thickness of the arrows signify the intensity of the
nystagmus. Note that the patient described in this chapter (Case 1) had a first degree left-beating
vestibular nystagmus as a result of a right-sided peripheral vestibular loss.

vestibular nystagmus and a gaze-evoked nystagmus. For example, when a patient

with a left-beating nystagmus looks to the left, both the gaze-evoked nystagmus
and the vestibular imbalance cause rightward slow eye movement, thereby
increasing the magnitude of the nystagmus. However, on right gaze, the vestibular
imbalance and the gaze-evoked nystagmus oppose one another, thereby decreasing
the intensity of the nystagmus.
Vestibular nystagmus, which is undirectional, is sometimes graded in severity
based upon its presence in different horizontal gaze positions. Specifically,
Alexander’s system, which was originally applied to patients observed during visual
fixation, includes first-degree, second-degree, and third-degree vestibular nystagmus. In
third-degree nystagmus, the nystagmus is undirectional and can be observed regard-
less of horizontal gaze position, but the intensity of the nystagmus is maximal with
gaze in the direction of the quick component of nystagmus and is minimal, but still
observable, when horizontal gaze is directed away from the quick component. In
second-degree nystagmus, the nystagmus is observed only when the patient gazes
straight ahead or in the direction of the quick component. In first-degree nystagmus,
the nystagmus can be observed only with gaze in the direction of the quick compo-
nent. This patient had a first-degree vestibular nystagmus since left-beating nystag-
mus was observed only with leftward gaze.
Case 1: Figure 2 The influence of loss of visual fixation on vestibular nystagmus (see Case 1:
Figure 1). Note that in its mildest form, a latent vestibular nystagmus will be absent in a lighted
room but present in darkness on lateral gaze. Note that left-beating nystagmus is illustrated.
A. Third degree, B. Second degree, C. First degree, D. Nystagmus only with loss of visual
fixation.

70
 CASE 1: UNILATERAL VESTIBULAR IMPAIRMENT AND VESTIBULAR COMPENSATION 71

Question 5: Why is the patient’s nystagmus increased in magnitude when she is wearing
infrared goggles?
Answer 5: Vestibular nystagmus, whether physiologic or pathologic, can be signifi-
cantly inhibited by visual fixation when vision and visual fixation and visual tracking
mechanisms are intact. Infrared or Frenzel goggles allow the patient’s eyes to be
observed while they significantly reduce visual fixation. An increase in a patient’s
nystagmus on wearing infrared or Frenzel goggles supports the idea that the
patient’s nystagmus originates from a vestibular imbalance, usually peripheral.
Case 1: Figure 2 illustrates the influence of loss of visual fixation on the various
grades of severity of vestibular nystagmus. Note that in its mildest form, a vestibular
nystagmus may be absent with visual fixation and observed only with loss of visual
fixation with lateral gaze to the right or to the left, depending on the direction of the
nystagmus. In clinical parlance, a horizontal-torsional nystagmus that increases in
magnitude with loss of visual fixation is called a vestibular nystagmus.

Laboratory Testing

Videonystagmography: Ocular motor testing was normal. Testing confirmed the presence
of a left-beating spontaneous vestibular nystagmus on left gaze that increased with loss of
visual fixation. Caloric testing revealed absent responses in the right ear, including absent
responses to ice-water irrigation. VEMPs were absent on the right.
Audiometric testing was normal.
An MRI scan of the brain with and without contrast with attention to the IACs (internal
auditory canal) and brainstem was normal.
Question 6: How do results of laboratory testing influence the diagnostic considerations
for this case?
Answer 6: The most significant finding on vestibular laboratory testing are the
reduced vestibular response in the right ear on caloric testing and the absent right
VEMP. Although a unilateral vestibular loss was suspected from the clinical evaluation,
laboratory testing provides objective evidence of a severe loss of sensitivity in the right
vestibular system that involves both the superior and inferior branches of the vestibular
portion of the eighth cranial nerve.
The normal audiometric test suggests that the patient is suffering from a pure
vestibular syndrome such as vestibular neuritis as opposed to a more generalized
labyrinthitis, which is commonly associated with a high-frequency hearing loss, or
from endolymphatic hydrops, which is often associated with a low-tone sensori-
neural hearing loss.
The normal MRI rules out a structural lesion.

Diagnosis/Differential Diagnosis

As noted, this patient is almost certainly suffering from vestibular neuritis3–5 (Case 1:
Figure 3). Other names for this condition include vestibular neurolabyrinthitis, vestibular
labyrinthitis, vestibular neuronitis, and acute vestibulopathy of uncertain etiology. These
terms are used interchangeably. It should be realized that a peripheral vestibular lesion
could actually be affecting the hair cells, the eighth nerve afferents, or the eighth nerve root
entry zone. From the vestibular signs and symptoms alone, a distinction cannot be made
72 VESTIBULAR DISORDERS

Case 1: Figure 3 Temporal bone section showing the vestibular nerve innervating the lateral
semicircular canal. The upper panel shows a normal nerve. The lower panel shows atrophy of
the vestibular nerve thought to be the result of a viral vestibular neuritis.
Source: With permission from Schuknecht HR, Kitamura K: Vestibular neuritis. Ann Otol Rhinol Laryngol
(suppl) 78(90):1–19, 1981. 5

among these three localizations. Postmortem temporal bone histopathology suggests that
Scarpa’s ganglion is affected primarily in vestibular neuritis.6 Case 1: Figure 3 illustrates
atrophy of the vestibular nerve thought to be the result of a viral vestibular neuritis.
Pathological data suggest that vestibular neuritis has a predilection for the superior division
of the vestibular nerve.7,8 Recent data that have used VEMPs suggest that up to 40% of
patients may have involvement of the inferior vestibular nerve.9 In this case, the patient’s
abnormal VEMPs on the right as well as abnormal caloric responses on the right suggest
involvement of both the superior and inferior branches of the vestibular nerve. The
patient’s MRI supports the diagnosis of a vestibular neuritis by ruling out a structural
lesion.
The patient was given a diagnosis of vestibular neuritis.

Treatment/Management

A short (10- to 14-day) course of corticosteroids—for example, prednisone, 1 mg/kg per

day—decreases the duration of vestibular symptoms,10 may also reduce the chance of
 CASE 1: UNILATERAL VESTIBULAR IMPAIRMENT AND VESTIBULAR COMPENSATION 73

future recurrent episodes of acute vertigo,11,12 and increases the likelihood of a return
of vestibular function.11 It is common practice not to prescribe corticosteroids if more than
1 month has lapsed since symptom onset. Antiviral agents such as acyclovir may be
considered since viral reactivation is thought to be involved in the pathogenesis of the
condition; however, there are no data to conclusively support its use in this setting and a
controlled study has shown no value for antiviral agents.11 This patient was treated with a
2-week course of corticosteroids. Vestibular suppressants and antinausea agents were also
prescribed on an as-needed basis for symptomatic relief (see Case 16). The patient was
referred for a course of vestibular rehabilitation (see Chapter 6).13,14

Follow-Up

The patient was seen in follow-up 1 month after the initial presentation. At that time, she
was very much improved and experienced symptoms only during rapid head movement,
which caused transitory dizziness and lightheadedness, and during walking in dimly lit or
dark environments. The patient also noted some difficulty with driving, especially imme-
diately after rapid head movements just before changing lanes.
Physical examination at the 1-month follow-up visit revealed no nystagmus with visual
fixation. However, behind infrared glasses, a low-amplitude, left-beating horizontal-
torsional nystagmus was observed with left gaze. The head thrust test was unchanged, that
is, still abnormal with rightward head movement. The patient’s gait had a normal base, but
there was some difficulty during tandem walking. The patient was able to stand on a
compliant foam pad even with her eyes closed with minimal difficulty.
The patient was advised to continue vestibular rehabilitation.
Question 7: By what process did this patient’s symptoms and signs almost completely
resolve?
Answer 7: Despite the fact that the patient’s vestibular loss in the right ear almost
certainly persists, vestibular compensation (see Chapter 1), a process that involves
rebalancing of the activity in central vestibular structures, has occurred. Through
this mechanism, vestibulo-ocular, vestibulospinal, perceptual, and autonomic
symptoms and signs improve substantially, athough some symptoms (as noted
above in this patient) are likely to persist. Vestibular compensation occurs auto-
matically in individuals with a normal central nervous system, normal vision and
proprioception, and adequate physical activity. This patient’s recovery is typical
even for individuals who have suffered complete unilateral peripheral vestibular
loss. The process of vestibular compensation is thought to involve brainstem and
cerebellar structures, so that resting activity in the left and right vestibular nuclei
becomes more or less balanced despite unilaterally reduced or absent vestibular
nerve activity. Early intervention with vestibular rehabilitation may have facilitated
her rapid improvement.

Summary

A 25-year-old woman presented with the acute onset of a vestibular syndrome indicative of
an acute unilateral peripheral vestibular loss. The patient’s history suggested a viral/
postviral affliction of the vestibular labyrinth or nerve. Examination revealed horizontal-
torsional spontaneous vestibular nystagmus, a positive head thrust test, pastpointing, and
74 VESTIBULAR DISORDERS

an inability to stand on a compliant foam surface with the eyes closed. Laboratory testing
revealed a right reduced vestibular response on both caloric and VEMP testing. An MRI
was normal. The patient was treated with a 2-week course of corticosteroids and vestibular
rehabilitation. Vestibular suppressant agents and antinausea agents were used only on an
as-needed basis. Through the process of vestibular compensation, the patient’s symptoms
decreased dramatically. At the 1-month follow-up evaluation, nystagmus was present only
with loss of visual fixation, and she could tandem walk and stand on a compliant surface.

Teaching Points

1. An acute unilateral vestibular syndrome is characterized by vertigo, nausea,

vomiting, blurred vision, and disequilibrium. These symptoms and signs result
from an imbalance between the afferent activity from the left and right labyrinths.
The central nervous system interprets this imbalance as a brisk continuous head rotation
toward the intact ear.
2. Vegetative symptoms of nausea, vomiting, and diaphoresis are caused by activity
in the pathways from the vestibular system to the autonomic nervous system.
3. The direction of acute vestibular nystagmus is typically horizontal-torsional. This
direction of nystagmus results primarily from the unopposed horizontal semicircular
canal afferent activity from the intact side that produces a horizontal direction of
nystagmus. The afferent activity from the two intact vertical semicircular canals sum
with one another such that torsionally the upper pole of the eye drifts (torts or rolls)
toward the lesioned ear. The vertical eye movement drives of the two vertical
semicircular canals cancel one another. The three unopposed semicircular canals of
the intact ear thus combine to produce a predominantly horizontal-torsional nystagmus
whose slow component is toward the lesioned ear and whose quick component (for
which the nystagmus direction is named) beats toward the intact ear.
4. Alexander’s law, wherein the intensity of nystagmus (including its frequency and
amplitude) increases when a patient looks in the direction of the quick component,
is typical of most types of nystagmus. The physiologic basis for Alexander’s law may
be related to changes in the neural integrator leading to gaze-evoked nystagmus.
5. Visual fixation inhibits vestibular nystagmus when vision and visual fixation/visual
tracking mechanisms are intact. Infrared or Frenzel goggles allow the patient’s eyes
to be observed while visual fixation is significantly reduced. Thus, an increase in a
patient’s nystagmus when wearing infrared or Frenzel glasses supports the idea that the
patient’s nystagmus originates from a vestibular imbalance. In clinical parlance, a
horizontal-torsional nystagmus that increases in magnitude with loss of visual
fixation is called vestibular nystagmus.
6. Vestibular compensation rebalances the neural activity in central vestibular
structures. This process causes a reduction of the symptoms and signs of an acute
vestibular syndrome. Through compensation, vestibulo-ocular, vestibulospinal,
perceptual, and autonomic symptoms and signs of the acute vestibular syndrome
largely resolve. Vestibular compensation occurs automatically in individuals with a
normal central nervous system, normal vision and proprioception, and adequate
physical activity. The process of vestibular compensation is thought to involve
brainstem and cerebellar structures, so that resting activity in the left and right
vestibular nuclei becomes more or less balanced despite unilaterally reduced or
absent vestibular nerve activity. Vestibular neuritis is the diagnostic designation
given to an acute vestibular syndrome, without obvious cause, that occurs
 CASE 1: UNILATERAL VESTIBULAR IMPAIRMENT AND VESTIBULAR COMPENSATION 75

without auditory or neurologic signs or symptoms. The underlying pathogenesis is

thought to involve viral activation within the vestibular nerve. Other conditions that can
cause an acute vestibular syndrome include endolymphatic hydrops, a demyelinating
disorder, and infarction involving the labyrinth or brainstem/cerebellum.
7. Treatment of vestibular neuritis with a short (10- to 14-day) course of
corticosteroids may decrease the duration of vestibular symptoms and may
improve long-term recovery.

References
1. Leigh RJ, Zee DS: Neurology of Eye Movements, ed 4. New York: Oxford University Press,
2006.
2. Hirvonen TP, Aalto H: Three-dimentional video-oculography in patients with vestibular
neuritis. Acta Otolaryngol 25:1–4, 2009.
3. Dix MR, Hallpike CS: The pathology, symptomotology and diagnosis of certain common
disorders of the vestibular system. Proc R Soc Med 45:341–354, 1952.
4. Coats AC: Vestibular neuronitis. Acta Laryngol (suppl) 251:5–28, 1969.
5. Schuknecht HF, Kitamura K: Vestibular neuritis. Ann Otol Rhinol Laryngol (suppl)
78(90):1–19, 1981.
6. Baloh RW, Lopez I, Ishiyama A, Wackym PA, Honrubia V: Vestibular neuritis:
Clinical–pathologic correlation. Otolaryngol Head Neck Surg 114:586–592, 1996.
7. Fetter M, Dichgan J: Vestibular neuritis spares the inferior division of the vestibular nerve.
Brain 119:755–763, 1996.
8. Gacek RR, Gacek MR: Vestibular neuronitis. Am J Otol 20:553–554, 1999.
9. Welgampola MS, Colebatch JG: Characteristics and clinical applications of vestibular-evoked
myogenic potentials. Neurology 64(10):1682–1688, 2005.
10. Shupak A, Issa A, Golz A, Kaminer M, Braverman I: Prednisone treatment for vestibular
neuritis. Otology & Neurotology 29:368–374, 2008.
11. Ariyasu L, Byl FM, Sprague MS, Adour KK: The beneficial effect of methylprednisolone in
acute vestibular vertigo. Arch Otolaryngol Head Neck Surg 116:700–703, 1990.
12. Strupp M, Zingler VC, Arbusow V, Niklas D, Maag KP, Dieterich M, Bense S, Theil D, Jahn
K, Brandt T: Methylprednisolone, valacyclovir, or the combination for vestibular neuritis.
N Engl J Med 351(4):354–361, 2004.
13. Strupp M, Arbusow V, Maag KP, Gall C, Brandt T: Vestibular exercises improve central
vestibulospinal compensation after vestibular neuritis. Neurology 51(3):838–844, 1998.
14. Hillier SL, Hollohan V: Vestibular rehabilitation for unilateral peripheral vestibular
dysfunction. Otolaryngol Head Neck Surg 138(4):415–417.
Case 2
Mixed Peripheral and
Central Vestibular
Impairment—
Cerebellopontine Angle
Tumor

History

A 65-year-old retired man had a chief complaint of dizziness that had been worsen-
ing during the past 6 months. The patient’s major symptom was disequilibrium
without vertigo, which was present daily, occurred with head movement, and was
particularly bothersome when walking. He noted veering of his gait both to the right
and to the left. There also was a complaint of hearing loss and tinnitus in the left ear
that was worsening gradually. He had no significant medical history, and the family
history was noncontributory.
Question 1: Based on the patient’s history, what diagnoses should be considered?
Answer 1: The patient’s history is consistent with both vestibular and auditory
abnormalities. Moreover, disequilibrium without vertigo and the gradually worsening
course suggest the possibility of a central vestibular abnormality. Diagnostic con-
siderations that can account for the patient’s hearing loss, tinnitus, and imbalance
include a cerebellopontine angle mass or, unlikely, a peripheral otologic condition.
The differential diagnosis for the patient’s balance symptoms independent of hearing
loss and tinnitus is quite broad.

Physical Examination

Neurologic examination indicated a Bruns’ nystagmus, that is, a coarse, gaze-evoked

nystagmus during leftward horizontal gaze and a fine vestibular (horizontal-torsional)
nystagmus on rightward gaze. There was no spontaneous nystagmus with eyes open in
room light. With infrared goggles, the patient was noted to have a primary-position, right-
beating, horizontal-torsional nystagmus of small amplitude. There was no alteration of

76
 CASE 2: MIXED PERIPHERAL AND CENTRAL VESTIBULAR IMPAIRMENT 77

strength or sensation or incoordination of the limbs. The patient had an ataxic gait.
Romberg’s test was negative but he could not stand on a compliant foam pad with eyes
closed. Bedside evaluation of the patient’s hearing indicated that Weber’s test lateralized to
the right and the Rinne test was positive bilaterally, indicating a sensorineural hearing loss
on the left.

Question 2: What is the mechanism of this patient’s nystagmus?

Answer 2: Bruns’ nystagmus is a combination of a gaze-evoked nystagmus in one
direction and a vestibular nystagmus that beats in the opposite direction. The
gaze-evoked nystagmus is based on a cerebellar lesion ipsilateral to the direction
of the gaze-evoked nystagmus. The vestibular nystagmus is based on a vestibular
lesion contralateral to the direction of the vestibular nystagmus. In this patient’s
case, the gaze-evoked nystagmus is left-beating on left gaze and suggests a
left-sided cerebellar lesion. The vestibular nystagmus is right-beating on right
gaze and suggests a left-sided vestibular lesion. Thus, this patient is likely to have
a left-sided cerebellar lesion and a left-sided vestibular lesion.1,2 Right-beating
vestibular nystagmus that can be observed in the primary position with infrared
goggles can often be seen only on right lateral gaze rather than in the primary
position when the patient is examined in the light (see Case 1 for a discussion of
Alexander’s law).
Question 3: Based on the patient’s history and physical examination, what is the most likely
abnormality and what diagnostic test(s) should be performed?
Answer 3: This patient is likely to have a left cerebellopontine angle neoplasm.
Diagnostic considerations include a large acoustic neuroma or meningioma; an
aneurysm acting as a mass lesion; one of a number of uncommon posterior fossa
neoplasms, such as an epidermoid tumor, chordoma, or lipoma; or, rarely, a
metastatic tumor. The patient should undergo MRI of the brain, with special
attention to the cerebellopontine angle. Auditory and vestibular testing would
also be helpful to delineate the patient’s functional abnormalities.

Laboratory Testing

Videonystagmography: Ocular motor testing revealed overshoot saccades to the left, an

asymmetric impairment of ocular pursuit with difficulty pursuing targets moving to the
left, and normal optokinetic nystagmus. A right-beating spontaneous vestibular nystagmus
was seen in the dark. Caloric testing revealed a reduced vestibular response of moderate
degree on the left. Rotational testing revealed asymmetric responses with more right-beating
nystagmus than left-beating nystagmus.
Vestibular-evoked myogenic potentials were absent on the left.
Posturography testing indicated excessive sway on conditions 5 and 6, that is, a
vestibular pattern.
Audiometric testing revealed a moderate to severe sensorineural hearing loss on the left
with a word recognition score of 30%. Hearing was normal on the right.
An MRI scan of the brain revealed a 4-cm mass in the left cerebellopontine angle that
filled the porus of the left internal auditory canal. There was a shift of the cerebellum and
brainstem caused by mass effect of the tumor (Case 2: Figure 1).
78 VESTIBULAR DISORDERS

Case 2: Figure 1 Axial magnetic resonance imaging of the brain demonstrating a 4-cm
cerebellopontine angle neoplasm consistent with an acoustic neuroma. Note the compression
and shift of the brainstem and cerebellum and distortion of the fourth ventricle. Arrowhead =
neoplasm; curved arrow = brainstem; open arrow = fourth ventricle.

Question 4: What additional information was provided by the laboratory testing?

Answer 4: The MRI scan confirms the clinical suspicion of a cerebellopontine angle
tumor. The scan is most suggestive of an acoustic neuroma. Audiometric testing
suggests that the patient has little functional hearing remaining in the left ear.
Vestibular laboratory testing confirms the presence of both peripheral vestibular
and central nervous system abnormalities. The patient’s caloric and VEMPs reduc-
tion suggests impairment of afferent vestibular activity on the left. The abnormal
saccades and pursuit suggest impairment of cerebellar/brainstem function. The
patient’s spontaneous nystagmus and directional preponderance on rotational
testing indicate an ongoing vestibulo-ocular asymmetry. Posturography suggests
that some of the patient’s imbalance is a result of vestibular dysfunction.

Diagnosis/Differential Diagnosis

This patient’s history, physical examination, and laboratory studies indicate a cerebello-
pontine angle lesion with a mixed central and peripheral vestibular disorder.
Question 5: In what way do combined peripheral and central vestibular abnormalities
interact to cause a synergistic adverse effect on a patient’s balance?
Answer 5: As noted in Case 1, patients with a normal central nervous system can
compensate for a peripheral vestibular lesion and become nearly symptom free.
Vestibular compensation requires changes in vestibular processing in the brainstem
and cerebellum, particularly the vestibulocerebellum (see Chapter 1). This patient’s
cerebellopontine angle lesion has caused a left–right vestibular asymmetry and, as
evidenced by the patient’s neurologic signs, has impaired the function of some of
the central nervous system structures important for vestibular compensation. Thus,
despite a vestibular loss that is gradual rather than acute and partial rather than
complete, this patient has symptoms of dizziness and imbalance suggesting that
vestibular compensation has not been successful.
 CASE 2: MIXED PERIPHERAL AND CENTRAL VESTIBULAR IMPAIRMENT 79

Question 6: What are the causes of combined peripheral and central vestibular dysfunction?
Answer 6: The causes of combined peripheral and central vestibular lesions include
large cerebellopontine angle lesions,3 as in this case; anterior inferior cerebellar
artery territory infarction (see Case 38); trauma (see Cases 13 and 21); and multi-
system degenerations (see Case 19), for example, Friedreich’s ataxia. Also, some
patients with peripheral vestibular lesions have preexisting central nervous system
abnormalities that prevent normal compensation from occurring (see Case 3).

Treatment/Management

The patient was treated surgically using a translabyrinthine approach. The diagnosis of an
acoustic neuroma was confirmed on pathologic analysis. Complete tumor resection was
accomplished with preservation of all cranial nerves except the eighth nerve, which was
resected with the tumor.
Postoperatively, the patient had no complications and was referred for vestibular
rehabilitation therapy (see Chapter 6).

Follow-Up

The patient recovered uneventfully from the surgery. Three months after surgery, he
reported tiring easily and continued to have mild to moderate unsteadiness and disequili-
brium. He was reassured and encouraged to keep up with his home vestibular rehabilitation
program and to avoid vestibular suppressant medications.

Summary

A 65-year-old man presented with a gradual onset of imbalance and unilateral tinnitus and
hearing loss over 6 months. Physical examination suggested a mixed central and peripheral
vestibular lesion. MRI scanning confirmed the presence of a cerebellopontine angle tumor.
Vestibular studies documented both peripheral and central vestibular abnormalities and
abnormalities of ocular motor control. The patient demonstrated impaired compensation
for his peripheral vestibular abnormality. Treatment consisted of surgical resection of the
tumor and vestibular rehabilitation. Follow-up evaluation showed mild to moderate resi-
dual unsteadiness.

Teaching Points

1. A cerebellopontine angle lesion should be suspected in the setting of dizziness

associated with unilateral or asymmetric hearing loss or tinnitus. Diagnostic
considerations should include a large acoustic neuroma or meningioma involving the
posterior fossa. Several uncommon tumors may also affect the posterior fossa, including
epidermoid tumor, chordoma, lipoma, or (rarely) metastatic tumor. A vertebrobasilar
aneurysm acting as a mass lesion may also present with similar symptoms. The patient
should undergo MRI of the brain, with special attention to the cerebellopontine angle.
2. Large cerebellopontine angle tumors may produce a combination of peripheral
and central vestibular abnormalities. Both vestibular nerve and cerebellar function
80 VESTIBULAR DISORDERS

may be impaired. These impairments may be manifested by abnormal ocular motor

tests, spontaneous nystagmus, a reduced vestibular response on caloric testing, a
directional preponderance on rotational testing, and abnormal posturography.
3. Combined peripheral and central vestibular abnormalities interact to cause a
synergistic adverse effect on a patient’s balance. With a normal central nervous
system, patients can compensate for a peripheral vestibular lesion and become nearly
symptom free. However, if central nervous system abnormalities involve the structures
that are critical for vestibular compensation, that is, the vestibular nuclei and the
vestibulo-cerebellum, a peripheral vestibular lesion may produce persistent symptoms
resulting from impaired compensation. Combined peripheral and central vestibular
dysfunction may be caused by large cerebellopontine angle lesions, anterior inferior
cerebellar artery territory infarction, trauma, and multisystem degenerations. Also,
some patients with peripheral vestibular lesions have preexisting central nervous
system abnormalities that prevent normal vestibular compensation from occurring.
4. Bruns’ nystagmus represents a manifestation of a combined peripheral and central
vestibular abnormality. Bruns’ nystagmus is a combination of a gaze-evoked
nystagmus in one direction, presumably based on an ipsilateral cerebellar lesion, and
a vestibular nystagmus in the opposite direction. Bruns’ nystagmus is highly suggestive
of a cerebellopontine angle tumor.

References

1. Lundborg T: Diagnostic problems concerning acoustic tumors. Acta Otolaryngol (suppl)

99:1–111, 1950.
2. Nedzelski JM: Cerebellopontine angle tumors: Bilateral flocculus compression as cause of
associated oculomotor abnormalities. Laryngoscope 93:1251–1260, 1983.
3. Baguley DM, Beynon GJ, Grey PL, Hardy DG, Moffat DA: Audio-vestibular findings in
meningioma of the cerebellopontine angle: A retrospective review. J Laryngol Otol
111:1022–1026, 1997.
Case 3
Impaired Vestibular
Compensation—Vestibular
Neuritis

History

A 65-year-old retired man presented with a complaint of 6 months of dizziness and

disequilibrium especially on compliant surfaces, such as plush carpet. Since their onset,
his symptoms were characterized by nearly constant imbalance when walking or standing
and lightheadedness even when seated. Rapid head movement exacerbated the patient’s
dizziness, which was associated with blurred vision. He did not complain of recent vertigo
or any positional symptoms. Specifically, there were no complaints of dizziness when
rolling over in bed. The patient noted no recent change in hearing or any tinnitus or aural
fullness. He was essentially asymptomatic when lying still.
The patient dated his symptoms to an acute episode of vertigo associated with nausea,
vomiting, and severe disequilibrium lasting for several hours 6 months before evaluation.
He had not complained of dizziness before that episode. He was evaluated by his primary
care physician and was believed to have a peripheral vestibular ailment. The patient was
treated with meclizine, 25 mg orally, three times daily. This provided some relief but was
minimally successful in alleviating his symptoms. The patient had to decrease his activity
level to such a degree that he no longer drove an automobile or took his morning walk and
discontinued gardening. Despite these changes in his activities, he continued to experience
daily dizziness, and his physician increased the dosage of his meclizine to 25 mg, four
times daily. Other than dizziness, the patient had no significant medical history. The family
history was noncontributory.

Question 1: Based on the patient’s history, what is the most likely diagnosis? Why is the
patient experiencing dizziness?
Answer 1: This patient’s most likely diagnosis is vestibular neuritis (see Case 1). Acute
vertigo unaccompanied by hearing loss, tinnitus, and aural fullness is unlikely to be
caused by Meniere’s disease (see Case 9). Other possibilities include an ischemic
insult to the vestibular labyrinth or nerve (see Case 38) or some other nonspecific
vestibulopathy. In any case, the patient’s history is consistent with an acute peripheral
vestibular ailment 6 months before evaluation.

81
82 VESTIBULAR DISORDERS

The patient’s persistent dizziness suggests that he has not compensated for his
presumed peripheral vestibular loss. Usually compensation requires several days or
weeks. This patient’s continued symptoms suggest impaired compensation. His
continued symptoms of instability during standing and walking suggest an
ongoing vestibulospinal abnormality. The patient’s blurred vision immediately
following head movement suggests a vestibulo-ocular abnormality. Meclizine
does not appear to be a successful treatment. Possibly, this medication is actually
worsening the patient’s symptoms by suppressing needed vestibular input and
interfering with vestibular compensation.

Physical Examination

General examination revealed an elderly appearing man who made minimal spontaneous
head movements. Neurologic examination revealed a few beats of right-beating nystagmus
on right-lateral gaze that were unsustained. Otherwise, the patient’s cranial nerve exam-
ination was normal. There were no changes in strength or sensation. There was no
incoordination. The patient’s gait was slow, with a short stride length. His head was held
rigidly during walking. The patient could tandem walk only with assistance. Romberg’s
test was negative. Otologic examination was normal. A low-amplitude right-beating
nystagmus was seen in the primary position with infrared goggles.
The head thrust test was abnormal to the left. Dix-Hallpike maneuvers were negative.
The patient could not stand on a compliant foam surface with the eyes open or closed.
Pastpointing was absent.
Question 2: What additional information regarding the cause of this patient’s dizziness was
provided by the physical examination?
Answer 2: The patient’s examination suggests that he is avoiding vestibular stimulation
by severely limiting his head movement. Moreover, the patient’s nystagmus,
although minimal, suggests an ongoing vestibulo-ocular asymmetry and a vestib-
ular compensation abnormality. It is likely that the patient has not compensated for
his presumed peripheral vestibular deficit. One reason for the patient’s failure to
compensate may be inadequate vestibular stimulation because he limits his head
movement so severely.

Laboratory Testing

Videonystagmography: Ocular motor function was normal. A very low amplitude right-
beating nystagmus was seen with the eyes open in the dark while seated and during
positional testing. This nystagmus increased with rightward gaze. Caloric testing revealed
a 50% reduced vestibular response on the left.
Rotational testing revealed responses of normal amplitude and timing. However, there
was a right-directional preponderance.
Posturography indicated a surface dependence pattern wherein the patient had excessive
postural sway whenever he was standing on a sway-referenced platform regardless of the
visual condition, that is, on conditions 4, 5, and 6 (see Chapter 4). He was able to maintain
his balance only when the support surface was fixed.
VEMPs were absent on the left.
Audiometric testing showed a mild high-frequency sensorineural hearing loss that was
symmetric in both ears. Word recognition scores were 100% bilaterally.
An MRI scan of the brain was normal.
 CASE 3: IMPAIRED VESTIBULAR COMPENSATION—VESTIBULAR NEURITIS 83

Case 3: Table 1 Causes of Impaired Compensation

Fluctuating vestibular function

Aberrant vestibular function
Subclinical involvement of the contralateral labyrinth
Central nervous system abnormality
Structural
Medication-induced
Sedentary lifestyle or fear-induced restriction of head movement
Multisensory impairment
Visual dysfunction
Somatosensory dysfunction

Question 3: What additional information does laboratory testing provide?

Answer 3: Laboratory testing indicates that the patient has both a left unilateral
peripheral vestibular reduction and an ongoing vestibulo-ocular and vestibulosp-
inal asymmetry. Moreover, the patient’s posturography abnormalities suggest that
he has become dependent on a rigid surface for maintaining balance. Taken
together, the findings suggest impaired vestibular compensation for a unilateral
peripheral vestibular insult despite the passage of 6 months since the patient’s acute
vestibular syndrome.
Question 4: What are the causes of impaired vestibular compensation for peripheral
vestibular injury? Which of these causes may be underlying this patient’s persistent
symptoms?
Answer 4: Vestibular compensation depends upon consistent peripheral vestibular
activity, even if reduced or only from one labyrinth, in combination with other
sensory inputs such as that from vision and somatosensation, and normal function
of central vestibular structures.1–3 Thus, failure to compensate for a peripheral
vestibular lesion can be based on fluctuating or aberrant peripheral vestibular
activity, a central nervous system abnormality that impairs vestibular compensation,
clinical or subclinical involvement of the contralateral ear, multiple sensory deficits,
or a sedentary lifestyle (Case 3: Table 1). Impaired vestibular compensation can be a
result of both structural abnormalities of the brain4 and dysfunction caused by
certain drugs such as benzodiazepines (see Chapter 8).
This patient’s failure to compensate for a peripheral vestibular lesion is probably
the result of a combination of a sedentary lifestyle and medication with vestibular
suppressants that together caused inadequate vestibular stimulation and impaired
vestibular compensation. The absence of vertigo and the constancy of symptoms
do not suggest fluctuating or aberrant vestibular input from the involved ear,
although this cannot be ruled out entirely. Also, there is nothing to suggest
abnormalities in other sensory systems.

Diagnosis/Differential Diagnosis

This patient’s history, physical examination, and laboratory studies suggest left-sided
vestibular neuritis and impaired compensation, that is, the patient has failed to undergo
normal vestibular compensation for his peripheral vestibular ailment.
84 VESTIBULAR DISORDERS

Treatment/Management

This patient was treated by gradually discontinuing meclizine over 1 week. Additionally, the
patient was scheduled for a course of vestibular rehabilitation in the hope of potentiating
compensation for his peripheral vestibular deficit. Vestibular rehabilitation was recom-
mended with the intent of reducing the patient’s symptoms of dizziness and blurred vision.
Another intent was to improve his balance by expediting vestibular compensation and
reduce his dependence upon somatosensation, that is, eliminate his surface dependence.

Summary

A 65-year-old man presented with a history of an episode of acute vertigo, nausea, and
vomiting 6 months prior to evaluation. The patient’s symptoms evolved into constant
disequilibrium. Physical examination suggested an ongoing vestibular imbalance. This
was confirmed by laboratory testing, which indicated a reduced vestibular response and
both vestibulo-ocular and vestibulospinal abnormalities. The patient was believed to
have a peripheral vestibular ailment with poor compensation centrally. His vestibular
suppressant medication was discontinued, and he was enrolled in a course of vestibular
rehabilitation.

Teaching Points

1. Persistent dizziness that continues for weeks or months following an acute

peripheral vestibular ailment may be the result of impaired vestibular
compensation. Typical symptoms of impaired compensation include instability
during standing and walking and blurred vision associated with quick head movements.
2. Patients with impaired vestibular compensation for a peripheral vestibular injury
often avoid vestibular stimulation by severely limiting head movements. Gait is
often slow, with a short stride length, and the head is held rigidly during walking and
turning. Although limiting head movements reduces vestibular stimulation and thus the
sensation of dizziness, this strategy is maladaptive because vestibular stimulation is
necessary to stimulate the process of vestibular compensation.
3. Failure to compensate for a peripheral vestibular lesion can be the result of one or
more factors. These include fluctuating or aberrant peripheral vestibular activity; a
central nervous system abnormality; clinical or subclinical involvement of the
contralateral ear; the presence of other sensory deficits, especially involving vision
and somatosensation; or a sedentary lifestyle. Central nervous system abnormalities that
impair vestibular compensation include both structural abnormalities and dysfunction
caused by certain drugs such as benzodiazepines.
4. Vestibular laboratory test results that are consistent with impaired vestibular
compensation include the presence of a spontaneous nystagmus, directional
preponderance on rotational testing, and abnormal platform posturography
testing.
5. Treatment of patients with impaired vestibular compensation includes tapering
vestibular suppressant medications and instituting a course of vestibular
rehabilitation.
 CASE 3: IMPAIRED VESTIBULAR COMPENSATION—VESTIBULAR NEURITIS 85

References
1. Hart C, McKinley P, Peterson B: Compensation following acute unilateral total loss of
peripheral vestibular function. In: Graham M, Kemink J (eds). The Vestibular System:
Neurophysiologic and Clinical Research. New York: Raven Press, 1987, pp 187–192.
2. Lacour M, Toupet M, Denise P, Christen Y (eds): Vestibular Compensation: Facts, Theories
and Clinical Perspectives. Proceedings of the International Symposium. Paris: Elsevier, 1988.
3. Smith P, Curthoys I: Mechanisms of recovery following unilateral labyrinthectomy: A review.
Brain Res Rev 14:155–180, 1989.
4. Furman JM, Balaban CD, Pollack IF: Vestibular compensation following cerebellar
infarction. Neurology 48:916–920, 1997.
Case 4
Bilateral Vestibular
Loss—Ototoxicity

History

A 39-year-old woman who did not work outside the home presented with a complaint of
dizziness, difficulty with vision, and instability while walking, especially in dimly lit
environments or when the floor was uneven. The patient’s complaints did not fluctuate
during the previous 6 months. She was asymptomatic when sitting or lying still. Visual
complaints were most noticeable when she was moving her head rapidly or riding in a
motor vehicle, during which she experienced jumbling of the visual surroundings.
Meclizine provided no relief of the patient’s symptoms but was still being used occasionally.
There was no complaint of vertigo, hearing loss, tinnitus, or aural fullness. The patient also
had no complaints of double vision, loss of vision, weakness, loss of sensation, or
incoordination aside from difficulty walking.
Question 1: Based on this portion of the patient’s history, what are the diagnostic
considerations?
Answer 1: Constant imbalance, absence of vertigo, and absence of associated
complaints of hearing loss or tinnitus all point away from a unilateral peripheral
vestibular ailment. The patient may be suffering from a central nervous system
abnormality affecting the balance system, such as a cerebellar abnormality.
However, the fact that the patient’s ambulation is worse in dimly lit environments
suggests a vestibular component. Also, the patient’s poor vision when the head is
moving, particularly in motor vehicles, suggests an impaired VOR.

Additional History

Upon further questioning, the patient related that she had noted the onset of her symptoms
of dizziness, difficulty with vision, and instability while walking approximately 1 week
after discharge from the hospital where she had been admitted because of complicated
cholecystitis. During that hospitalization, she had been treated with intravenous gentamicin
for 2 weeks. The patient stated that, to the best of her knowledge, the gentamicin was given
at an appropriate dose, with drug levels ascertained regularly. The patient also indicated

86
 CASE 4: BILATERAL VESTIBULAR LOSS—OTOTOXICITY 87

that she had a history of Sjogren’s syndrome, which had been in remission for approximately
2 years. There was no significant family history.

Physical Examination

Neurologic examination revealed full extraocular movements without nystagmus. The

remainder of the neurologic examination was normal, except that the patient had gait
ataxia with a widened base. Romberg’s test was negative. Otoscopic examination was
normal. Decreased audibility to finger rub was noted in both ears. The patient’s visual
symptoms could be reproduced by applying a gentle vibratory motion with the index finger
to the head just lateral to the outer canthus of the eye while the opposite eye was occluded.
On neurotologic examination, there was no nystagmus behind infrared goggles. On head
thrust testing, refixation saccades were noted with head movement both to the right and to
the left. During ophthalmoscopy, the patient was asked to move her head back and forth at a
high frequency with very small excursions. The optic disc was noted to move with the
patient’s head movements rather than remain stable in space. The patient was unable to
stand on a compliant foam surface with her eyes closed without falling. Gait was wide
based and unsteady.
Question 2: Based upon the additional historical information and the physical examination,
what is the patient’s likely diagnosis?
Answer 2: This patient is probably suffering from bilateral vestibular loss as a result of
aminoglycoside ototoxicity, which causes hair cell damage (Case 4: Figure 1). The
patient is manifesting Dandy’s syndrome, that is, the combination of oscillopsia
(jumbling of the visual surround) and gait ataxia caused by the bilateral loss of
vestibular function.1 Dandy popularized vestibular nerve section as a treatment for
Meniere’s disease in 1928.2 Many of Dandy’s patients underwent bilateral vestibular
nerve sections that resulted in oscillopsia and gait ataxia, a symptom complex that
now bears his name. Abnormal head thrust test bilaterally,3 motion of the fundus
during head movement, and abnormal reduction in visual acuity with head

(a) (b)

Case 4: Figure 1 Histopathology of aminoglycoside ototoxicity. (A) Normal utricular macula.

(B) Utricular macula following aminoglycoside-induced ototoxicity. Note the flattening of
the sensory epithelium and loss of stereocilia, denoting destruction of the utricular hair cells.
Thick straight arrow5utricular macula; double arrows5sensory epithelium (hair cells) with
stereocilia extending from their upper surface (panel A); open arrowhead5otolithic membrane;
curved arrow5endolymphatic membrane surrounding the utricle.
88 VESTIBULAR DISORDERS

Case 4: Table 1 Commonly Used Ototoxic Medications

Aminoglycoside antibiotics
Streptomycin
Gentamicin
Tobramycin
Chemotherapeutic/anticancer agents
Cisplatinum
Diuretics
Furosemide
Ethacrynic acid
Erythromycin
Salicylates

movement indicate a reduced VOR. The past history of Sjogren’s syndrome is of

uncertain significance. Because Sjogren’s syndrome is an autoimmune disorder that
may be associated with vestibular loss (see Case 45), the patient may have had a
combination of autoimmune inner ear disease and ototoxicity. By some unknown
mechanism, the patient may have been more susceptible to ototoxicity because of
her Sjogren’s syndrome.

Question 3: What are the causes of bilateral vestibular loss? What laboratory tests should
be requested?
Answer 3: Bilateral vestibular loss is most commonly a result of ototoxicity
from aminoglycosides, including gentamicin, tobramycin, and streptomycin.4
Commonly used medications that are ototoxic are listed in Case 4: Table 1. Other
pharmaceutical agents, such as cisplatinum, can cause bilateral vestibular loss.
Diagnostic considerations for bilateral vestibular loss besides ototoxicity include
bilateral Meniere’s disease, otosclerosis, Paget’s disease, a history of meningitis,
multiple cranial neuropathies, congenital abnormalities, neurofibromatosis type II
(bilateral acoustic neuroma), autoimmune inner ear disease (Case 45), syphilis and
vestibular loss in association with neurodegenerative syndromes that cause deaf-
ness (e.g., Friedreich’s ataxia), and idiopathic causes.5 Thus, further laboratory
testing should include rheumatologic parameters, such as an erythrocyte sedimen-
tation rate and antinuclear antibody measurement, as well as a serum fluorescent
treponemal antibody absorption test (FTA-ABS). Audiometry should be performed
to determine whether there is a hearing loss associated with the patient’s vestibular
loss. Quantitative vestibular laboratory testing, including rotational testing, should
be requested to confirm the extent of vestibular loss.
In the case of bilateral vestibular loss in the presence of bilateral hearing loss, the
patient should have an MRI scan to rule out the unlikely occurrence of bilateral mass
lesions such as acoustic neuromas or cerebellopontine angle tumors.

Laboratory Testing

Videonystagmography: Ocular motor testing was normal. There was no static positional
nystagmus. Caloric testing revealed absent responses in both ears even to ice-water
irrigation.
 CASE 4: BILATERAL VESTIBULAR LOSS—OTOTOXICITY 89

Rotational testing revealed markedly reduced responses such that no eye movements
were generated at frequencies below 0.5 Hz and there were only a few beats of nystagmus
following deceleration from a constant velocity rotation of 90 degrees per second.
Posturography indicated excessive sway on conditions 5 and 6, that is, a vestibular
pattern. Audiometric testing indicated a bilateral asymmetric sensorineural hearing loss
(Case 4: Figure 2).
VEMPs were present in both ears (Case 4: Figure 3).
The left ear had primarily a high-frequency hearing loss. The right ear had a flat hearing
loss.

Case 4: Figure 2 Audiogram.

Case 4: Figure 3 Vestibular-evoked myogenic potentials indicating reduced, but not absent,
responses bilaterally.
90 VESTIBULAR DISORDERS

An MRI scan of the brain was normal.

The patient had a normal erythrocyte sedimentation rate and negative antinuclear
antibody and FTA-ABS measurements.
Question 4: What information does vestibular laboratory testing provide for diagnosis and
treatment?
Answer 4: The patient’s laboratory test indicates bilateral vestibular loss confirmed
by ice-water caloric testing, high intensity rotational testing, and vestibular-evoked
myogenic potentials. Note that despite the absence of response to ice-water caloric
testing, rotational testing and VEMP testing both suggest impaired but not absent
vestibular function. Posturography supports the diagnosis by indicating an inability
to control upright balance when forced to rely on vestibular information. Regarding
treatment, this patient will require therapy to potentiate nonvestibular sensory
inputs.
Question 5: What is the value of assessing hearing in the evaluation of the dizzy patient?
Answer 5: Because the vestibular and auditory periphery share common inner-ear
fluid homeostasis, blood supply, nerves, and location within the temporal bone (see
Chapter 1), disorders that affect the peripheral vestibular apparatus often affect
hearing as well. An evaluation of hearing can help to localize a vestibular system
disorder to the periphery and often can help to lateralize an abnormality. In addi-
tion, certain vertigo syndromes have characteristic types of associated hearing loss,
for example, endolymphatic hydrops, which is frequently associated with a low-
tone sensorineural hearing loss with good word recognition, whereas vestibular
neuritis is characterized by normal hearing. Compression of the eighth cranial nerve
bundles within the internal auditory canal and/or cerebellopontine angle by a
tumor can also produce symptoms of unsteadiness and disequilibrium as well as
hearing loss. In this situation, the hearing loss is usually primarily in the high
frequencies, and word recognition is relatively poor.

Diagnosis/Differential Diagnosis

This patient is manifesting bilateral vestibular loss as a result of aminoglycoside

ototoxicity.

Treatment/Management

Question 6: Prevention is the best management for ototoxicity. What factors should alert
the physician to the possible occurrence of ototoxicity?
Answer 6: The major risk factors for the occurrence of bilateral vestibulopathy when
using ototoxic drugs include impaired renal function, age greater than 65, prior use
of ototoxic drugs, high serum levels of ototoxic drugs, preexisting sensorineural
hearing loss, and a medical course greater than 14 days. Some patients may have a
genetic predisposition to aminoglycoside ototoxicity,6 but there is currently no
clinically available test for identifying these individuals. Symptoms of bilateral
vestibular loss can be progressive and also delayed from weeks to months even
after the drug has been stopped.3
 CASE 4: BILATERAL VESTIBULAR LOSS—OTOTOXICITY 91

Case 4: Table 2 Strategies for Patients with Bilateral Vestibular Loss

Sensory substitution
Altered patterns of head motion
Preprogramming of slow eye movements in anticipation of head movements
Potentiation of the cervico-ocular reflex
Saccidic substitution
Perceptual adjustments to decrease oscillopsia

Question 7: Based on the patient’s diagnosis and laboratory test findings, what are the
appropriate strategies for managing her disequilibrium?
Answer 7: This patient is suffering from bilateral vestibular loss. Treatment should
include discontinuation of all vestibular-suppressant medications. Also, the patient
should be referred for a course of vestibular rehabilitation therapy to encourage the
use of sensory input other than that from the vestibular system, such as from vision
and proprioception. A properly fitted cane can provide increased proprioceptive
input. Full-frame lenses rather than bifocals can help to provide needed visual input
during ambulation especially on stairs. The patient should also be cautioned to
remove all loose rugs from the home, install night lights, and install hand rails on
stairways and in the bathroom.
Question 8: Aside from discontinuing vestibular suppressants and encouraging the
use of alternative sensory inputs, what other modalities are available to patients with
bilateral vestibular loss to develop spatial orientation and stable vision while the
head is moving?
Answer 8: Possible strategies for patients with bilateral vestibular loss are listed in
Case 4: Table 2. The use of nonvestibular sensory inputs such as vision and proprio-
ception is the primary means of partially overcoming the effects of bilateral reduction
of vestibular function. During head movements, stabilization of vision can be
achieved, in part, by alterations of patterns of head movement such that the head
is moved more slowly. Some patients can learn to preprogram slow compensatory eye
movements in anticipation of head movements. Also, the cervico-ocular reflex can be
potentiated in such patients7,8 (see Case 58). Saccadic eye movements can be
substituted for slow eye movements. There can be a perceptual adjustment to
decrease the effect of oscillopsia.9 These behavioral adjustments may occur sponta-
neously to a greater or lesser extent in an individual patient. However, by working
with a therapist, patients with bilateral vestibular loss can be helped to achieve
optimal ocular motor and balance function while decreasing symptoms10 (see
Chapter 6).
The patient was treated with discontinuation of vestibular-suppressant medica-
tions and a course of vestibular rehabilitation therapy. The therapist provided the
patient with a cane.

Follow-Up

The patient improved somewhat, especially in regard to her symptoms of dizziness while
moving. Unfortunately, although improved, the patient still had gait instability in poorly
lighted environments, and poor balance when walking on uneven flooring, and complained
of oscillopsia during fast head movements.
92 VESTIBULAR DISORDERS

Summary

A 39-year-old woman presented with oscillopsia and ataxia that began following treatment
with an aminoglycoside antibiotic for cholecystitis. The patient had a history of Sjogren’s
syndrome that may have predisposed her to ototoxicity. Laboratory testing confirmed the
presence of bilateral vestibular reduction and did not reveal any evidence of autoimmune
disease. The patient was treated with discontinuation of vestibular-suppressant medica-
tions, a cane, and a course of vestibular rehabilitation therapy designed to train the patient
to use other sensory modalities and to adopt other behaviors to substitute for her vestibular
function. Following treatment, the patient had decreased symptoms and was functionally
improved but still impaired.

Teaching Points

1. The combination of oscillopsia and ataxia (Dandy’s syndrome) is pathognomonic

for bilateral vestibular loss.
2. Bilateral vestibular loss most commonly occurs as a result of aminoglycoside-
induced ototoxicity. Other pharmaceutical agents such as cisplatinum can also cause
bilateral vestibular loss. Bilateral vestibular loss may also be caused by bilateral
Meniere’s disease, autoimmune inner ear disease, otosyphilis, bilateral acoustic
neuromas, or may be idiopathic.
3. Laboratory testing of patients with bilateral vestibular loss is essential. Testing
should include rheumatologic parameters, such as an erythrocyte sedimentation rate and
antinuclear antibody and serum FTA-ABS measurements. Audiometry should be
performed to evaluate the pattern of any associated hearing loss. Quantitative
vestibular laboratory testing should be requested to confirm the extent of vestibular
loss. Rotational testing and VEMPs are particularly helpful in this regard. An MRI scan
should be performed if bilateral acoustic neuromas are suspected.
4. Hearing assessment is a fundamental part of the evaluation of the dizzy patient.
Because the vestibular and auditory periphery share common inner-ear fluid
homeostasis, blood supply, nerves, and location within the temporal bone, disorders
that affect the peripheral vestibular apparatus often affect hearing as well. An evaluation
of hearing can help to localize a vestibular system disorder to the periphery and can
often help to lateralize an abnormality.
5. The type of hearing loss can help to diagnose vestibulopathy. Several vertigo
syndromes have characteristic types of associated hearing loss. For example,
endolymphatic hydrops is frequently associated with a low-tone sensorineural hearing
loss with good word recognition, whereas vestibular neuritis is characterized by normal
hearing. Compression of the eighth cranial nerve bundles within the internal auditory
canal and/or cerebellopontine angle by a tumor can produce a hearing loss that is usually
worse in the high frequencies, with impaired word recognition.
6. Prevention is the best management for ototoxicity. The major risk factors for the
occurrence of bilateral vestibulopathy when using aminoglycoside antibiotics include
impaired renal function, age greater than 65, prior use of ototoxic drugs, high serum
levels of ototoxic drugs, preexisting sensorineural hearing loss, and drug exposure
longer than 14 days. Symptoms of bilateral vestibular loss can be progressive and can
be delayed for weeks to months following discontinuation of an aminoglycoside
antibiotic.
 CASE 4: BILATERAL VESTIBULAR LOSS—OTOTOXICITY 93

7. Treatment for bilateral vestibular loss should include discontinuation of all

vestibular-suppressant medications and referral for a course of vestibular
rehabilitation therapy. Patients should be taught how to use sensory input other than
that from the vestibular system, such as from vision and proprioception. A properly
fitted cane can provide increased proprioceptive input. The patient should also be
cautioned to remove all loose rugs from the home, install night lights, and install
hand rails on stairways and in the bathroom. Full-frame lenses rather than bifocals
also may benefit ambulation. If possible, the patient should not receive further ototoxic
medications.

References
1. ‘‘JC’’: Living without a balancing mechanism. N Engl J Med 246:458–460, 1952.
2. Dandy WE: Meniere’s disease: Its diagnosis and methods of treatment. Arch Surg 16:1127,
1928.
3. Halmagyi GM, Weber KP, Aw ST, Todd MJ, Curthoys IS: Impulsive testing of semicircular
canal function. Prog Bran Res 171:187–194, 2008.
4. Rybak LP, Matz GJ: Auditory and vestibular effects of toxins. Manifestations of systemic
disease. In: Cummings W (ed). Otolaryngology—Head and Neck Surgery, Vol 4. St Louis: CV
Mosby, 1986, pp 3161–3172.
5. Baloh RW, Jacobson K, Honrubia V: Idiopathic bilateral vestibulopathy. Neurology 39:
272–275, 1989.
6. Casano RA, Johnson DF, Bykhovskaya Y, Torricelli F, Bigozzi M, Fischel-Ghodsian N:
Inherited susceptibility to aminoglycoside ototoxicity: Genetic heterogeneity and clinical
implications. Am J Otol 20:151, 1999.
7. Kasai T, Zee DS: Eye–head coordination in labyrinthine-defective human beings. Brain Res
144:123–141, 1978.
8. Bronstein AM, Hood JD: The cervico-ocular reflex in normal subjects and patients with absent
vestibular function. Brain Res 373:399–408, 1986.
9. Wist ER, Brandt T, Krafczyk S: Oscillopsia and retinal slip. Brain 106:153–168, 1983.
10. Herdman SJ (ed): Vestibular Rehabilitation, ed 2. Philadelphia: FA Davis, 2000.
Case 5
Anxiety and Psychiatric
Dizziness—Vestibulopathy,
Cause Unknown

History

A 43-year-old woman who worked as an accountant presented with the chief complaint of
dizziness for the last several years. Her symptoms were described as a sense of light-
headedness and disequilibrium without true vertigo. Lightheadedness was constantly
present at a low level. The patient suffered periodic exacerbations lasting minutes to hours.
She was particularly bothered by rapid head movements and by certain environments,
such as shopping malls, grocery stores, and driving on winding roads. Additionally, she
occasionally experienced tingling of the fingers and toes associated with her dizziness. She
also related that she avoided heights. There was no positional sensitivity, hearing loss, or
tinnitus. She had a history of panic attacks in her 20s that resolved. She could not recall
whether she had been medicated for these attacks.
Question 1: Based on the history, what are the diagnostic possibilities for this patient?
Answer 1: This patient has nonspecific complaints that are difficult to localize entirely
to the vestibular system. Moreover, her history suggests a symptom complex that
has been labeled space and motion discomfort,1 which refers to symptoms elicited
by a specific stimulus pattern in some patients with vestibular dysfunction and in
some with panic disorder. Space and motion discomfort can occur in situations
characterized by inadequate or confusing visual or kinesthetic information for
normal spatial orientation. Space and motion discomfort coupled with intermittent
paresthesias strongly suggests an anxiety component to the patient’s problem.
Moreover, the patient avoids heights and had suffered from panic attacks pre-
viously. Thus, this patient may have a vestibular disorder, an anxiety disorder, or both.

Physical Examination

Neurologic examination revealed square-wave jerks, that is, small, involuntary to-and-fro
saccades on and off the point of visual regard. The patient was unaware of these eye
movements. Examinations of her motor system, sensation, and coordination were normal.

94
 CASE 5: ANXIETY AND PSYCHIATRIC DIZZINESS 95

The patient was able to tandem walk without difficulty. Romberg’s test was negative.
Otologic and neuro-otologic examinations were normal, including no difficulty standing
on a foam pad with the eyes closed.

Laboratory Testing

Videonystagmography: Ocular motor, positional, and caloric tests were normal.

Rotational testing revealed responses of normal amplitude and timing with a significant
right directional preponderance.
VEMPs were normal.
Posturography was normal.
Question 2: In what way does the additional information from the physical examination
and vestibular laboratory testing influence the diagnostic considerations?
Answer 2: The patient’s square-wave jerks are a nonspecific finding often seen in the
elderly, in whom they are of no clinical significance. In young adults, however,
square-wave jerks are considered abnormal and may indicate a brainstem or cere-
bellar abnormality (see Case 49). The combination of normal caloric responses,
normal VEMPs, normal posturography, and a directional preponderance on rota-
tional testing suggests an ongoing vestibulo-ocular asymmetry without peripheral
vestibular disease or vestibulospinal. Thus, the patient may have a central nervous
system abnormality. Taken together, the patient’s history, physical examination,
and laboratory abnormalities suggest an anxiety disorder and a central vestibular
abnormality as well.
Question 3: What is psychogenic dizziness?
Answer 3: Psychogenic dizziness is a term used by many clinicians synonymously with
psychic dizziness, psychiatric dizziness, psychophysiologic dizziness, and functional
dizziness.2,3,4 The use of the term psychogenic dizziness can be criticized for several
reasons. A large number of patients who fulfill the diagnostic criteria for a psychiatric
disorder may also have vestibular dysfunction. Indeed, there is a definite association
between anxiety disorders and vestibular disorders.5 We prefer to use the term
psychiatric dizziness for those patients in whom dizziness occurs exclusively in
combination with other symptoms as part of a recognized psychiatric symptom
cluster3 (see Chapter 7). For example, dizziness that occurs as a component of the
symptom cluster of panic attacks should be called psychiatric dizziness.
Question 4: What is the role of hyperventilation in the evaluation of patients with suspected
anxiety disorders?
Answer 4: The hyperventilation test has been described by Drachman and Hart6 and
Nedzelski and colleagues (1986).7 They described dizziness related to 3 minutes of
hyperventilation. A questionable practice is to consider dizziness psychogenic if a
patient’s sensations can be replicated by hyperventilation. Herr and associates
(1989) found that the hyperventilation test was positive in approximately 20% of
patients who had diagnoses other than that of vestibular dysfunction, thereby
indicating a lack of specificity of the hyperventilation test.8 Also, recent studies
have suggested that hyperventilation may induce nystagmus in patients with
acoustic neuroma.9 The sensitivity of the hyperventilation test is also unknown.
Thus, the results of the hyperventilation test should be interpreted with great
caution.
96 VESTIBULAR DISORDERS

Diagnosis/Differential Diagnosis

The patient’s symptoms of dizziness with rapid head movement coupled with abnormal
vestibular laboratory studies suggest a vestibular system abnormality. Her history of space
and motion discomfort, avoidance of heights, paresthesias, and a remote history of panic
attacks suggests an anxiety disorder. Thus, this patient has both a vestibular disorder of
uncertain etiology and anxiety.
Question 5: What is the cause-and-effect relationship, if any, between vestibular disorders
and anxiety disorders?
Answer 5: Three functional mechanisms that are not necessarily exclusive might
account for the association between vestibular abnormalities and anxiety disorders:
the somatopsychic, psychosomatic, and neurologic linkage mechanisms.5,10 The
somatopsychic model postulates that vestibular sensations are catastrophically
reinterpreted by the patient as signifying immediate danger. Agoraphobic avoid-
ance develops as a result of this situational specificity of vestibular symptoms, for
example, space and motion discomfort. The psychosomatic model postulates that
vestibular dysfunction occurs as a result of anxiety or hyperventilation, perhaps by
altering central vestibular processing. In favor of this mechanism are the observa-
tions that increases in vestibular responses occur with heightened arousal and
hyperventilation alters vestibular responses on the rotational test and the positional
test.11–13 The neurologic linkage model10 postulates that anxiety disorders, in
combination with vestibular and audiologic dysfunction, involve abnormal activity
in overlapping or interconnected areas in the brainstem, such as the locus coeruleus
and the parabrachial nucleus.

Treatment/Management

Question 6: What is the appropriate treatment for this patient, who has a vestibular system
abnormality and appears to have an anxiety disorder as well?
Answer 6: Treatment approaches to patients with anxiety that may be related to
vestibular dysfunction are currently under development. No controlled outcome
studies have been conducted; however, in a prospective study of sertraline in
24 patients with subjective dizziness, about 75% of these patients responded.14
The vestibular disorder and the anxiety symptoms should be treated simu-
ltaneously. The vestibular disorder should be treated in the same manner as a
nonspecific vestibulopathy independent of the presence of anxiety (see Case 16).
The treatment of anxiety includes pharmacotherapy and behavioral therapy.
Pharmacotherapy could include anti-anxiety agents (see Case 8: Table 3). Note
that benzodiazepines act as both a vestibular suppressant and an anxiolytic and
thus are an excellent first choice of treatment for such patients.
Question 7: Should this patient be referred to a psychiatrist for further evaluation?
Answer 7: Controlled studies are necessary to evaluate the role of psychiatric treat-
ment for patients with both a balance disorder and a psychiatric disorder. However,
psychiatric referral is definitely warranted for patients who are suffering from a
clinically significant anxiety disorder, such as patients with frequent panic attacks
and patients suffering from panic disorder with agoraphobia.
 CASE 5: ANXIETY AND PSYCHIATRIC DIZZINESS 97

This patient was treated with a combination of vestibular rehabilitation therapy

and clonazepam 0.25 mg by mouth, twice daily. Psychiatric consultation was
deferred.
Question 8: Should this patient be referred for a course of vestibular rehabilitation
therapy?
Answer 8: Vestibular rehabilitation therapy is a recognized treatment for patients
with vestibular disorders (see Chapter 6). Also, a recent study has suggested that
vestibular rehabilitation therapy may benefit patients with dizziness and anxiety.15

Summary

A 43-year-old woman presented with a history consistent with both a vestibular system
abnormality and an anxiety disorder. Physical examination and laboratory testing further
suggested the absence of significant neurologic disease but did suggest a vestibular
imbalance. This patient conditon should be diagnosed as ‘‘vestibulopathy of uncertain
etiology’’ with associated anxiety. The patient was treated with low-dose benzodiazepines
and vestibular rehabilitation therapy.

Teaching Points

1. Anxiety often accompanies dizziness. The cause-and-effect relationship between

anxiety and dizziness is uncertain but may be related to a somatopsychic,
psychosomatic, or common neurologic mechanism.
2. Space and motion discomfort, that is, symptoms elicited by situations
characterized by inadequate or confusing visual or kinesthetic information
necessary for normal spatial orientation, is often seen in patients who are both
anxious and dizzy.
3. The term psychogenic dizziness should be avoided.
4. The term psychiatric dizziness can be used to describe dizziness that occurs
exclusively in combination with other symptoms as part of a recognized
psychiatric symptom cluster. For example, dizziness that occurs as a component of
the symptom cluster of panic attacks should be called psychiatric. The term psychiatric
dizziness should not be used to describe patients who have anxiety solely in association
with a balance disorder.
5. The hyperventilation test has no demonstrable clinical value and results should be
interpreted with great caution.

References

1. Jacob RG, Woody SR, Clark DB, Lilienfeld SO, Hirsch BE, Kucera GD, Furman JM, Durrant
JD: Discomfort with space and motion: A possible marker of vestibular dysfunction
assessed by the Situational Characteristics Questionnaire. J Psychopathol Behav Assessment
15:299–324, 1993.
2. Jacob RG, Furman JM, Balaban CD: Psychiatric aspects of vestibular disorders. In: Baloh
RW, Halmagyi M (eds). Disorders of the Vestibular System. New York: Oxford University
Press, 1996, pp 509–528.
3. Furman JF, Jacob RG: Psychiatric dizziness. Neurology 48(5):1161–1166, 1997.
4. Moore BE, Atkinson M: Psychogenic vertigo. Arch Otolaryngol 67:347–353, 1958.
98 VESTIBULAR DISORDERS

5. Furman JF, Jacob RG: A clinical taxonomy of dizzinesss and anxiety in the otoneurological
setting. J Anxiety Disorders 15:9–26, 2001.
6. Drachman DA, Hart CW: An approach to the dizzy patient. Neurology 22:323–334, 1972.
7. Nedzelski JM, Barber HO, McIlmoyl L: Diagnoses in a dizziness unit. J Otolaryngol
15(2):101–104, 1986.
8. Herr RD, Zun L, Matthews JJ: A directed approach to the dizzy patient. Ann Emerg Med
18(6):664/101–672/109, 1989.
9. Minor LB, Haslwanter T, Straumann D, Zee DS: Hyperventilation-induced nystagmus in
patients with vestibular schwannoma. Neurology 53(9):2158–2168, 1999.
10. Balaban CD, Jacob RG: Background and history of the interface between anxiety and vertigo.
J Anxiety Disorders 15:27–51, 2001.
11. Collins WE: Arousal and vestibular habituation. In: Kornhuber HH (ed). Vestibular System
Part 2: Psychophysics, Applied Aspects and General Interpretations. Berlin: Springer-Verlag,
1974, pp 361–368.
12. Theunissen EJM, Huygen PLM, Folgering HTH: Vestibular hyperreactivity and
hyperventilation. Clin Otolaryngol 11:161–169, 1986.
13. Monday LA, Tetrault L: Hyperventilation and vertigo. Laryngoscope 109:1003–1010, 1980.
14. Staab JP, Ruckenstein MJ, Amsterdam JD: A prospective trial of sertraline for chronic
subjective dizziness. Laryngoscope 114(9):1637–1641, 2004.
15. Jacob RG, Whitney SL, Detweiler-Shostak G, Furman JM: Vestibular rehabilitation for
patients with agoraphobia and vestibular dysfunction: A pilot study. J Anxiety Disorders
115:131–146, 2001.
Case 6
Emergency Room
Management of the Dizzy
Patient—Acute Cerebellar
Infarction

History

A 60-year-old man presented to an emergency room with a history of several hours of

vertigo. The patient related that while watching a sporting event on television he had an
acute onset of vertigo, nausea, and, shortly thereafter, vomiting. The patient was unable to
walk without assistance at home and was brought to the emergency department by
ambulance. His vertigo had remained constant. He also complained of a mild headache
and blurred vision. The patient had not suffered from previous episodes of vertigo. He also
denied having any recent viral infections. His medical history was significant for hyperten-
sion, which was well controlled with a beta-blocker.
Question 1: Based upon the patient’s history, what are the diagnostic considerations?
Answer 1: The patient’s history is consistent with an acute vestibular syndrome
such as that seen with vestibular neuritis (see Cases 1, 3) or Meniere’s disease
(Case 9). However, other causes of an attack of prolonged spontaneous vertigo
must also be considered,1 including labyrinthine ischemia (Case 38), cerebellar
infarction2,3 or hemorrhage, brainstem infarction (Case 37) or hemorrhage, multi-
ple sclerosis (Case 30), venous thrombosis,4 and bacterial otomastoiditis (Case 43).
Of these, vestibular neuritis is the most common cause of an acute attack of
prolonged spontaneous vertigo. However, the patient’s mild headache and
medical history of hypertension increase the likelihood of central nervous system
ischemia.

Physical Examination

General medical examination was normal except that the patient’s blood pressure was
elevated to 140/100. Neurologic examination revealed a normal mental status and normal
pupillary responses with full extraocular movements. A left-beating horizontal-torsional
nystagmus was noted in the primary position with fixation. The intensity of nystagmus

99
100 VESTIBULAR DISORDERS

increased with leftward gaze and decreased with rightward gaze. The remainder of
the cranial nerve examination was normal including facial sensation and movement,
palatal sensation and movement, and tongue movement. Motor examination revealed
normal strength in all extremities. There was no pronator drift. Deep tendon reflexes
were normal. Babinski’s sign was absent bilaterally. Coordination testing revealed subtle
difficulty with finger-to-nose testing on the right. Sensation testing was normal to all
modalities. The patient was unable to walk without assistance. Romberg’s test was
positive; the patient fell toward the left. Otologic examination was normal. Neurotologic
examination revealed an increase in the patient’s left-beating nystagmus with loss of visual
fixation. The head thrust testing was equivocal because of the presence of spontaneous
nystagmus.
Question 2: Based upon the additional information from the physical examination, what is
the most likely diagnosis?
Answer 2: The patient has an abnormal physical examination that is consistent with
an acute vestibular syndrome. The patient has a vestibular nystagmus, as evidenced
by the character of the nystagmus. It was horizontal-torsional, continued in the
same direction with changes in gaze, and increased with loss of visual fixation. This
finding strongly supports an acute loss of vestibular function on the right, and the
most common cause is vestibular neuritis.
Question 3: Can an acute central nervous system abnormality present with nystagmus that
appears like an acute peripheral vestibular loss?
Answer 3: Yes. Acute central vestibular disorders such as brainstem or cerebellar
infarction or hemorrhage typically cause gaze-evoked nystagmus, that is, nystag-
mus that changes direction with a change in gaze direction. However, patients with
cerebellar stroke may demonstrate nystagmus that is present in only one direction
of gaze, thus appearing to have nystagmus due to an acute peripheral
vestibular loss.5
Although a peripheral etiology seems likely in this patient, the patient’s inability
to walk, subtle difficulty with coordination, and falling on Romberg’s test to the left
rather than to the right should increase the suspicion of an acute central nervous
system abnormality. Infarction or hemorrhage in the posterior fossa must seriously
be considered.
Question 4: Should brain imaging be performed urgently?
Answer 4: Yes, brain imaging should be performed urgently when symptoms and
signs are present that are not fully typical of acute peripheral vertigo or if the patient
has known risk factors for stroke.

Laboratory Testing

An MRI scan of the brain revealed an infarction involving the right cerebellar hemisphere
(Case 6 Figure 1).

Diagnosis/Differential Diagnosis

The patient was given a diagnosis of acute cerebellar infarction.

 CASE 6: EMERGENCY ROOM MANAGEMENT OF THE DIZZY PATIENT 101

Case 6: Figure 1 MRI scan of a right inferior cerebellar infarction. The inset illustrates the vascular
supply to the inferior cerebellum, which is perfused by the medial and lateral branches of the posterior
inferior cerebellar artery (PICA) and the anterior inferior cerebellar artery (AICA).
Source: With permission from Hotson JR, Baloh RW: Acute vestibular syndrome. N Engl J Med 339:680–685,
1998.5

Treatment

The patient received an urgent neurosurgical evaluation and underwent decompression

surgery.

Follow-Up

Following a 1-week hospitalization, the patient entered a rehabilitation center and

gradually regained the ability to ambulate without assistance, although he used a
cane.
Question 5: What are the common diagnoses of patients evaluated in the emergency room
for dizziness?
Answer 5: A study by Alvord and Herr6 reviewed the eventual diagnosis of 93
consecutive patients presenting to an emergency room with a primary complaint
of dizziness. The distribution of diagnoses in that review is given in Case 6: Table 1.
Most patients presenting to an emergency room with dizziness suffer from periph-
eral vestibular abnormalities, but a significant number of patients present with
central nervous system causes. In a study by Toker et al. of 9,472 cases of dizziness
seen in emergency departments in the United States, 5.6% of patients had
102 VESTIBULAR DISORDERS

Case 6: Table 1 Specific Diagnoses of Patients with Dizziness in an

Emergency Room

Classification Diagnosis N

Central Cerebellar infarct 2

Alcohol or drug toxicity 2
Brain tumor 1
Central nervous system concussion 1
Hepatic encephalitis 1
Hypertension 1
Hyponatremia 1
Multiple sclerosis 1
Pseudotumor 1
Total 11
Peripheral Acute labyrinthitis 18
Peripheral vestibular disorder 17
‘ Benign positional vertigo 7
Meniere’s disease 4
Labyrinthine concussion 4
Cervical disorder 2
Serous otitis media 1
Total 53
Other Hyperventilation 3
Psychogenesis 2
Malingering 1
Fumes intoxication 1
Cystitis 1
Migraine 1
Total 9
Unknown Total 20
Source: With permission from Alvord LSS, Herr RD: ENG in the emergency room: Subtest
results in acutely dizzy patients. J Am Acad Audiol 5:384–389, 1994.6

vestibular neuritis/labyrinthitis, 1.1% had migraine, 1% had BPPV or Meniere’s

disease, and 0.6% had a stroke or intracranial hemorrhage.7
Question 6: What types of nonvestibular dizziness must be considered when evaluating a
patient in the emergency room?
Answer 6: Case 6: Table 2 provides a detailed list of the differential diagnoses
for patients with nonvestibular dizziness who might be seen in an emergency
room.8

SUMMARY

A 60-year-old man presented to an emergency room with a history of several hours of vertigo.
Symptoms had begun abruptly and were associated with mild headache. The medical history
was significant for hypertension. Physical examination revealed a normal mental status, a left-
beating vestibular nystagmus, a subtle difficulty with finger-to-nose testing on the right, and an
 CASE 6: EMERGENCY ROOM MANAGEMENT OF THE DIZZY PATIENT 103

Case 6: Table 2 Differential Diagnosis for Nonvestibular Vertigo

1. Cardiac 4. Gastrointestinal
a.Acute myocardial infarction a. Nausea and vomiting
b. Cardiac arrhythmia b. Diarrhea
c. Cardiomyopathy c. GI bleed
d. Congestive heart failure 5. Vascular
e. Valvular heart disease a. Coarctation of aorta
f. Carotid sinus syndrome b. Thoracic dissection
2. Pulmonary/Respiratory c. Subclavian steal syndrome
a. Hypoxia d. Superior vena cava syndrome
b. Asthma e. Carotid artery stenosis
c. COPD 6. Orthostatic Hypotension
d. CHF a. Medications
3. Toxic/Metabolic/Endocrine b. Prolonged bed rest
a. Polypharmacy c. Volume depletion
b. Diabetes mellitus (hyper- or hypoglycemia) d. Anemia
c. Thyroid disease (hyper- or hypothyroidism) e. Neurogenic disorders (autonomic
d. Parathyroid disease (hyper- or. neuropathy)
hypoparathyroidism) 7. Psychiatric
e. Adrenal disease (Cushing’s or . d. Addison’s a. Anxiety
disease) b. Depression
f. Electrolyte abnormalities
g. Volume depletion
h. Azotemia/uremia
Source: Modified from Walker JS, Barnes SB: Dizziness. Emerg Med Clin North Am 16(4):845–875, 1998.8

inability to walk without assistance. An MRI scan of the brain revealed a cerebellar infarction.
The patient received an urgent neurosurgical evaluation. He gradually regained the ability to
ambulate without assistance, although he used a cane.

Teaching Points

1. A diagnosis of posterior fossa infarction or hemorrhage should be considered for

patients who present to an emergency room with acute onset of vertigo.
2. Signs of a central nervous system cause of acute vertigo may be subtle and include
an inability to ambulate without assistance.
3. Brain imaging should be performed urgently when signs and symptoms are
present that are not fully typical of acute peripheral vertigo or if the patient has
known risk factors for stroke.
4. Nonvestibular dizziness must be considered when evaluating a patient in the
emergency room.

References
1. Baloh RW: Dizziness: Neurological emergencies. Neurol Clin North Am 16(2):305–321,
1998.
2. Lee H, Sohn SI, Cho YW, Lee SR, Ahn BH, Park BR, Baloh RW: Cerebellar infarction
presenting isolated vertigo. Neurology 67:1178–1183, 2006.
104 VESTIBULAR DISORDERS

3. Savitz S, Caplan LR, Edlow J: Pitfalls in the diagnosis of cerebellar infarction. Acad Emerg
Med 14:63–68, 2007.
4. Kim HA, Sohn SI, Hyung L: Cerebral venous thrombosis mimicking acute unilateral vesti-
bulopathy. Neurol Sci 29:41–43, 2008.
5. Hotson JR, Baloh RW: Acute vestibular syndrome. N Engl J Med 339:680–685, 1998.
6. Alvord LSS, Herr RD: ENG in the emergency room: Subtest results in acutely dizzy patients. J
Am Acad Audiol 5:384–389, 1994.
7. Newman-Toker DE, Hsieh YH, Camargo CA, Pelletier AJ, Butchy GT, Edlow JA: Spectrum
of dizziness visits to US emergency departments: Cross-sectional analysis from a nationally
representative sample. Mayo Clin Proc 83(7):765–775, 2008.
8. Walker JS, Barnes SB: Dizziness. Emerg Med Clin North Am 16(4):845–875, 1998.
Part III

Common Disease Case Studies

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Case 7
Benign Paroxysmal
Positional Vertigo

History

A 45-year-old man complained of positional vertigo that had begun 6 weeks before
evaluation. Symptoms occurred when he rolled over in bed to the right and when he
reached above his head. There were no other neurologic or otologic symptoms. His history
was significant for a 1-day episode of severe vertigo, nausea, and vomiting that had
occurred 2 months before evaluation. An emergency room physician at that time diagnosed
labyrinthitis and prescribed promethazine, which the patient was still taking on an irregular
basis. The patient had several days of nausea and severe imbalance following this acute
episode; during this time, he was unable to work in his usual occupation as an attorney.
Since returning to work, the patient reported a sense of mild disequilibrium and unsteadi-
ness during quick head movements. These symptoms were gradually improving, and he
was almost entirely asymptomatic at rest but still reported positional vertigo.1,2
Question 1: Based on the patient’s history, what is the most likely diagnosis?
Answer 1: This patient’s history is consistent with an episode of vestibular neuritis
(see Cases 1 and 3) 2 months before evaluation. He seems to have largely recovered
from the vestibular neuritis but has persistent symptoms related to positional
vertigo that probably are a result of benign paroxysmal positional vertigo.

Physical Examination

General, neurologic, and otologic examinations were normal except for impaired tandem
gait. Neurotologic examination revealed no nystagmus while seated using infrared goggles
and an inability to stand on a compliant foam pad with his eyes closed. Dix-Hallpike
maneuvers using infrared goggles were positive with the right ear down. The nystagmus
was upbeating (toward the forehead) and torsional, with the upper poles of the eyes beating
toward the dependent (right) ear. The nystagmus began several seconds after positioning
and was accompanied by a strong sense of vertigo and nausea. It lasted for about 15
seconds, after which time the vertigo also stopped.

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108 VESTIBULAR DISORDERS

Question 2: How does the additional information provided by the physical examination
influence this patient’s diagnosis?
Answer 2: This patient manifests the characteristic symptoms and signs of benign
paroxysmal positional nystagmus and vertigo, including the typical nystagmus
evoked by Dix-Hallpike maneuvers. Also, the patient’s abnormal neurotologic
examination suggests a lingering vestibular imbalance, probably the result of the
vestibular neuritis suffered 2 months earlier.

Laboratory Testing

Videonystagmography: Ocular motor function was normal. There was no static positional
nystagmus. Dix-Hallpike maneuvers in the laboratory documented a predominantly upbeat-
ing nystagmus with the right ear down. (Note that two-dimensional videonystagmography,
the technique that is currently available clinically, does not measure torsional eye move-
ments.) Caloric irrigations revealed a significant (40%) right reduced vestibular response.
Rotational testing revealed a mild left directional preponderance.
Posturography indicated excessive sway on conditions 5 and 6, that is, a vestibular
pattern.
VEMPs were abnormal on the right with a reduced amplitude.
Question 3: What is the significance of the vestibular laboratory abnormalities?
Answer 3: Taken together, these findings suggest that the patient is suffering from a
partial right-sided peripheral vestibular loss, benign paroxysmal positional vertigo
affecting the right ear, and ongoing vestibulo-ocular and vestibulospinal asymmetry.
The right reduced caloric response suggests that the presumed vestibular neuritis,
which the patient suffered 2 months earlier, damaged afferent fibers in the superior
branch of the vestibular portion of the right eighth nerve or the sensory epithelia of
the right horizontal semicircular canal. The reduced VEMPs on the right suggest
involvement of the sacculus or the inferior vestibular nerve. The patient’s directional
preponderance on rotational testing suggests an ongoing VOR asymmetry, that is,
incomplete compensation for a peripheral vestibular deficit. This incomplete recov-
ery may be based on fluctuating peripheral vestibular function on the right, chronic
use of vestibular suppressants (see Case 16), or some other cause that is not obvious.
The vestibular pattern on platform posturography suggests an ongoing vestibulosp-
inal abnormality, which represents further evidence of incomplete central nervous
system compensation. The nystagmus elicited during Dix-Hallpike maneuvers con-
firms the diagnosis of benign paroxysmal positional vertigo.

Diagnosis/Differential Diagnosis

Question 4: Are there any conditions other than benign positional nystagmus and vertigo
that should be considered?
Answer 4: Unquestionably, this patient’s most likely diagnoses are resolving vestib-
ular neuritis and benign paroxysmal positional vertigo. Other entities that can
present with an acute vestibular syndrome followed by benign paroxysmal posi-
tional vertigo are labyrinthine concussion (see Cases 13 and 21) and labyrinthine
infarction (see Case 38). Rarely, posterior fossa lesions can present with the typical
signs and symptoms of benign paroxysmal positional vertigo,3,4 although with
 CASE 7: BENIGN PAROXYSMAL POSITIONAL VERTIGO 109

central causes of positional vertigo, one or more features of the clinical presentation
are often atypical, such as the direction of the nystagmus.
Question 5: What features in the clinical presentation of a patient with an acute vestibular
syndrome followed by positional vertigo would lead to a suspicion of a posterior fossa
lesion and if seen by a physical therapist would prompt a physician referral?
Answer 5: Neurologic symptoms such as numbness or weakness of the face or
extremities, or visual loss associated with the onset of vertigo, should lead to the
suspicion of a posterior fossa lesion. Additionally, if the neurologic examination
disclosed any central nervous system signs such as downbeating nystagmus or if the
patient’s Dix-Hallpike maneuvers were associated with a response atypical of
benign positional nystagmus and vertigo, further evaluation, such as MRI scanning
of the posterior fossa, would be warranted. Responses during the Dix-Hallpike
maneuver that are atypical of benign paroxysmal positional vertigo include nys-
tagmus that (1) is downbeating rather than upbeating in the head-hanging posi-
tion, (2) occurs immediately upon positioning, (3) is not associated with dizziness
or vertigo, (4) persists, that is, is not paroxysmal, (5) does not fatigue if the patient is
repeatedly positioned, or (6) neurologic signs and symptoms suggestive of brain-
stem or cerebellar dysfunction such as weakness or numbness.
This patient was given a diagnosis of benign paroxysmal positional vertigo.
Question 6: What is the pathophysiology of benign paroxysmal positional vertigo?
Answer 6: Benign paroxysmal positional vertigo is thought to result from malfunc-
tion of the posterior semicircular canal such that the canal becomes abnormally
sensitive to gravity or linear acceleration. Malfunction of the posterior semicircular
canal in benign paroxysmal positional vertigo is supported by two observations:

1. The direction of provoked nystagmus is consistent with the ocular motor

connections of the dependent posterior semicircular canal. That is, excitation
of the posterior semicircular canal leads to excitation of the superior oblique
and contralateral inferior rectus muscles. Thus, in benign paroxysmal positional
vertigo, the patient manifests a predominantly upbeating-torsional nystagmus
that becomes more upbeating when gazing away from the down ear and
more torsional when gazing toward the down ear.
2. Surgical sectioning of the afferent nerve to the posterior semicircular canal
abolishes benign paroxysmal positional vertigo.

There are two current theories to explain why the posterior semicircular canal
becomes sensitive to gravity: cupulolithiasis and canalithiasis.
Cupulolithiasis refers to the idea that detached otoconia from the utricle descend
to the most inferior portion (when upright) of the labyrinth and become adherent
to the cupula of the posterior semicircular canal.5,6 These adherent particles change
the specific gravity of the cupula so that it no longer is isodense with the surround-
ing endolymph. As a result, the posterior semicircular canal cupula becomes a
gravity-sensitive organ in certain positions. Consequently, the posterior semicircu-
lar canal falsely signals continuous rotation for particular head positions, for exam-
ple, tipping the head backward.
Canalithiasis refers to the idea that debris, possibly degenerating otoconia or
other cellular debris, becomes free-floating in the endolymph of the posterior
semicircular canal (Case 7: Figure 1).7–10 Any head movement that changes the
orientation of the posterior semicircular canal with respect to gravity may cause the
110 VESTIBULAR DISORDERS

Case 7: Figure 1 The Dix-Hallpike test of a patient with benign paroxysmal positional vertigo
affecting the right ear. In Panel A, the examiner stands at the patient’s right side and rotates the
patient’s head 45 degrees to the right to align the right posterior semicircular canal with the
sagittal plane of the body. In Panel B, the examiner moves the patient, whose eyes are open,
from the seated to the supine right-ear-down position and then extends the patient’s neck
slightly so that the chin is pointed slightly upward. The latency, duration, and direction of
nystagmus, if present, and the latency and duration of vertigo, if present, should be noted.
The arrows in the inset indicate the direction of nystagmus in patients with typical benign
paroxysmal positional vertigo. The presumed location in the labyrinth of the free-floating
debris thought to cause the disorder is also shown.
Source: With permission from Furman JM, Cass SP: Benign paroxysmal positional vertigo. N Engl J Med
341:1590–1596, 1999.10

particles in the endolymph to move within the posterior semicircular canal.

Presumably, as the particles move, the endolymph is disturbed in a manner that
stimulates the posterior semicircular canal ampulla. Once the particles settle into a
dependent position and stop moving, which presumably takes about 10 or 20
seconds, the abnormal stimulation ceases. When the patient returns to the upright
position, the particles may again move and again cause an erroneous sensation of
 CASE 7: BENIGN PAROXYSMAL POSITIONAL VERTIGO 111

Case 7: Figure 2 Free-floating endolymph particles within the posterior semicircular canal
observed during surgery. The posterior semicircular canal had been opened in preparation for a
canal-plugging procedure. White debris was observed within the endolymph compartment of
the posterior semicircular canal. These two photographs are sequential in time and show that the
particles shifted during movement of the patient’s head; compare the shape and position of
particles at the straight arrow with those at the curved arrow.
Source: With permission from Parnes LS, McClure JA: Free-floating endolymph particles: A new operative
finding during posterior semicircular canal occlusion. Laryngoscope 102:988–992, 1992. 12

motion. Note that Dix-Hallpike maneuvers may need to be performed repeatedly to

establish a diagnosis.11
Both the cupulothiasis and canalithiasis theories have merit, and it is possible that
both exist as pathologic conditions. However, the concept of cupulolithiasis cannot
explain why the nystagmus provoked by head positioning stops after 15 to 30
seconds. If debris remained attached to the cupula, one would expect nystagmus
to continue unabated for a long period of time. It is necessary to hypothesize that
another mechanism, for example, central adaptation, is involved in stopping the
nystagmus or that the debris is released from the cupula, in which case the debris
become free-floating, as hypothesized in the concept of canalithiasis. Strong support
for the canalithiasis theory includes surgical observations of free-floating particles
within the posterior semicircular canals of patients with benign paroxysmal posi-
tional vertigo (Case 7: Figure 2).12 Moreover, the latency, duration, and fatigability
of the nystagmus that characterize benign paroxysmal positional vertigo can all be
explained by the theory of canalithiasis without invoking other central mechanisms.

TREATMENT/MANAGEMENT

Question 7: What are the treatment options for benign paroxysmal positional vertigo?
What is the role of medications such as vestibular suppressants? Should this patient
continue using promethazine?
Answer 7: Benign positional nystagmus and vertigo are best treated using the
particle repositioning maneuver (Case 7: Figure 3).9,13 Previously, habituating
Case 7: Figure 3 Bedside maneuver for the treatment of a patient with benign paroxysmal positional vertigo
affecting the right ear. The presumed position of the debris within the labyrinth during the maneuver is shown in each
panel. The maneuver is a three-step procedure. First, a Dix-Hallpike test is performed with the patient’s head rotated 45
degrees toward the right ear and the neck slightly extended, with the chin pointed slightly upward. This position results
in the patient’s head hanging to the right (Panel A). Once the vertigo and nystagmus provoked by the Dix-Hallpike test
cease, the patient’s head is rotated about the rostral-caudal body axis until the left ear is down (Panel B). Then the head
and body are further rotated until the head is face down (Panel C). The vertex of the head is kept tilted down throughout
the rotation. The maneuver usually provokes brief vertigo. The patient should be kept in the final face-down position for
about 10 to 15 seconds. With the head kept turned toward the left shoulder, the patient is brought into the seated position
(Panel D). Once the patient is upright, the head is tilted so that the chin is pointed slightly downward.
Source: With permission from Furman JM, Cass SP: Benign paroxysmal positional vertigo. N Engl J Med 341:1590–1596, 1999.10

112
 CASE 7: BENIGN PAROXYSMAL POSITIONAL VERTIGO 113

Case 7: Figure 4 Brandt-Daroff exercises for benign paroxysmal positional vertigo.

Source: With permission from Herdman SJ: Assessment and management of benign paroxysmal positional
vertigo. In: Herdman, SJ. Vestibular Rehabilitation. Philadelphia: FA Davis, 1999, p 464. 15

exercises, such as those described by Brandt and Daroff14 (Case 7: Figure 4), and
other physical maneuvers, such as the liberatory maneuver,16 were most popular.
All of these treatments are designed to relocate endolymphatic debris, which is
presumed to be near or adherent to the posterior semicircular canal cupula, to the
labyrinthine vestibule, where the debris no longer affects the semicircular canals
and can be naturally reabsorbed. The particle-repositioning maneuver is a one-time
therapy, whereas the Brandt-Daroff exercises generally require 1 to 2 weeks of
twice-daily performance. During particle repositioning, mastoid vibration can be
used but is probably unnecessary.17 Post-treatment restrictions, such as staying
upright for 1 to 2 days, also may not be necessary.18,19 In the rare patient who
cannot be cured of benign paroxysmal positional vertigo with a physical maneuver
or with exercises, surgical treatment is usually successful20,21 (see Case 39).
Vestibular-suppressant medication is often helpful at the onset of benign parox-
ysmal positional nystagmus and vertigo, especially if it follows an acute vestibular
loss, as in this patient, or if a patient is so apprehensive that he or she refuses to
perform the habituating exercises if needed. However, once the acute episode of
vestibular imbalance, if present, is over, vestibular-suppressant medication should
be avoided, since central vestibular compensation for the peripheral vestibular loss
can be delayed. If the patient expects to be exposed to excessive motion, such as
prolonged car or air travel, or becomes particularly symptomatic for a brief time,
meclizine, clonazepam, diazepam, or promethazine prescribed on an as-needed
basis (see Case 16) may be beneficial.
A course of vestibular rehabilitation may be useful, even if the positional vertigo is
cured by a repositioning maneuver, especially for a patient with evidence on
114 VESTIBULAR DISORDERS

physical examination or laboratory testing of an ongoing vestibular system imbal-

ance such as a directional preponderance or abnormal posturography.
Treatment of this patient consisted of a particle-repositioning maneuver, gradual
discontinuation of the patient’s vestibular-suppressant medication, and a course of
vestibular rehabilitation. The patient had complete relief from his positional symp-
toms and gradually recovered nearly normal balance.22 His limitations were noticed
only during taxing balance tasks such as water-skiing.
Question 8: What is the natural history of benign paroxysmal positional nystagmus and
vertigo? Is this patient likely to recover from this condition?
Answer 8: Benign paroxysmal positional vertigo is usually a self-limited condition.
That is, without treatment, most patients recover spontaneously over several weeks
or months. The typical patient with benign paroxysmal positional vertigo seeks
specialty treatment about 6 weeks after the onset of the vertigo (mean, 16 months;
range, 5 days to many years).18 It has been shown that without specific interven-
tion, 75% of patients have spontaneous resolution of symptoms, with a mean
duration of about 1 month (range, 5 to 42 days) of further symptoms.23 Thus, for
most patients, the duration of benign paroxysmal positional vertigo is about 10
weeks. However, in 25% of patients, symptoms can continue for years. The natural
history of benign paroxysmal positional vertigo speaks to the value of actively
treating such patients, especially since the condition can continue for years in a
significant minority. Benign paroxysmal positional vertigo also may recur, often 6
months to 6 years following the initial presentation. The cumulative recurrence rate
following particle repositioning is about 1% per month.24 The patient should be
advised of this possibility. Repositioning maneuvers are equally effective in treating
recurrences.
Some patients with recurrences of benign paroxysmal positional vertigo may
benefit from self-treatment with particle repositioning at home.25 Only reliable and
otherwise appropriate patients should be advised and educated to perform home
particle repositioning.

Summary

A 45-year-old man presented with positional vertigo following acute vestibular neuritis
that had occurred 2 months before evaluation. The physical examination was consistent
with benign paroxysmal positional vertigo. An ongoing vestibulo-ocular and vestibulosp-
inal asymmetry was suggested by both the physical examination and laboratory test results.
Treatment consisted of a particle-repositioning maneuver, gradual discontinuation of the
patient’s vestibular-suppressant medication, and a course of vestibular rehabilitation
therapy. The patient had complete relief of his positional symptoms and gradually recov-
ered nearly normal balance.

TEACHING POINTS

1. The characteristic symptoms and signs of benign paroxysmal positional nystagmus

and vertigo include a history of positionally induced vertigo and a nystagmus
evoked by the Dix-Hallpike maneuver that is upbeating (fast component toward
the forehead) and torsional with the upper poles of the eyes beating toward the
 CASE 7: BENIGN PAROXYSMAL POSITIONAL VERTIGO 115

dependent (right) ear. The nystagmus begins several seconds after positioning and is
accompanied by definite vertigo. The nystagmus lasts for about 15 seconds, after which
time the vertigo also stops.
2. Benign paroxysmal positional vertigo is thought to result from malfunction of
the posterior semicircular canal such that the canal becomes abnormally
sensitive to gravity or linear acceleration. The most likely explanation for this
malfunction is that debris, possibly degenerating otoconia or other cellular debris,
becomes free-floating in the endolymph of the posterior semicircular canal. Any
head movement that changes the orientation of the posterior semicircular canal
with respect to gravity may cause these particles in the endolymph to move within
the posterior semicircular canal.
3. Benign paroxysmal positional vertigo can be seen as a sequela of other disorders,
such as vestibular neuritis and labyrinthine concussion. Benign paroxysmal
positional vertigo may be only one of several manifestations of an ongoing vestibular
abnormality. Patients presenting with positional vertigo should be thoroughly evaluated
for other evidence of otologic disease. Patients presenting with disequilibrium for any
reason should be evaluated for benign paroxysmal positional vertigo with appropriate
questioning and physical examination, even if they do not present with a chief
complaint of positional vertigo.
4. Atypical positional vertigo should suggest a posterior fossa lesion. Atypical features
include any neurologic symptoms or signs that cannot be ascribed to a peripheral
vestibular localization, any atypical features on the response to Dix-Hallpike
maneuvers, and failure to respond to particle-repositioning maneuvers.
5. The preferred treatment for benign paroxysmal positional vertigo is the particle-
repositioning maneuver. This is highly successful and provides complete relief in
nearly all patients. Vestibular-suppressant medications can be used early in the disorder,
but after several days it should be used sparingly, if at all.
6. Benign paroxysmal positional vertigo is usually a self-limited condition. Without
specific intervention, 75% of patients have spontaneous resolution of symptoms, with a
mean duration of about 1 month (range, 5 to 42 days) of further symptoms. Benign
paroxysmal positional vertigo also may recur, often 6 months to 6 years following the
initial presentation. The cumulative recurrence rate following particle repositioning is
1% per month. Some patients with recurrences benefit from self-treatment with particle
repositioning performed at home.

References
1. Bhattacharyya N, Baugh RF, Orvidas L, Barrs D, Bronston LJ, Cass S, Chalian AA, Desmond
AL, Earll JM, Fife TD, Fuller DC, Judge JO, Mann NR, Rosenfeld RM, Schuring LT, Steiner
RW, Whitney SL, Haidari J, American Academy of Otolaryngology-Head and Neck Surgery
Foundation: Clinical practice guideline: Benign paroxysmal positional vertigo. Otolaryngol
Head Neck Surg 139(5 Suppl 4):S47-81, 2008.
2. Fife TD, Iverson DJ, Lempert T, Furman JM, Baloh RW, Tusa RJ, Hain TC, Herdman S,
Morrow MJ, Gronseth GS: Quality Standards Subcommittee, American Academy of
Neurology 70(22):2067–2074, 2008.
3. Watson P, Barber HO, Deck J, Terbrugge K: Positional vertigo and nystagmus of central
origin. Can J Neurol Sci 8:133–137, 1981.
4. Dunniway HM, Welling DB: Intracranial tumors mimicking benign paroxysmal positional
vertigo. Otolaryngol Head Neck Surg 118:429–436, 1998.
5. Schuknecht HF: Positional vertigo: Clinical and experimental observations. Trans Am Acad
Ophthalmol Otolaryngol 166:319–332, 1962.
116 VESTIBULAR DISORDERS

6. Schuknecht HF: Cupulolithiasis. Arch Otolaryngol 90:113–126, 1969.

7. Harbert F: Benign paroxysmal positional nystagmus. Arch Ophthalmol 84:298–302, 1970.
8. Hall SF, Ruby RRF, McClure JA: The mechanics of benign paroxysmal vertigo. J Otolaryngol
8:151–158, 1979.
9. Epley JM: The canalith repositioning procedure: For treatment of benign paroxysmal posi-
tional vertigo. Otolaryngol Head Neck Surg 107:399–404, 1992.
10. Furman JM, Cass SP: Benign paroxysmal positional vertigo. N Engl J Med 341:1590–1596,
1999.
11. Pollak L: The importance of repeated clinical examination in patients with suspected benign
paroxysmal positional vertigo. Otol Neurotol [Epub ahead of print 2009].
12. Parnes LS, McClure JA: Free-floating endolymph particles: A new operative finding during
posterior semicircular canal occlusion. Laryngoscope 102:988–992, 1992.
13. Parnes LS, Price-Jones R: Particle repositioning maneuver for benign paroxysmal positional
vertigo. Ann Otol Rhinol Laryngol 102:325–331, 1993.
14. Brandt T, Daroff RB: Physical therapy for benign paroxysmal positional vertigo. Arch
Otolaryngol 106:484–485, 1980.
15. Herdman SJ: Vestibular Rehabilitation. Philadelphia: FA Davis, 1999, p 464.
16. Semont A, Greyss G, Vitte E: Curing the BPPV with a liberatory maneuver. Adv
Otorhinolaryngol 42:290–293, 1988.
17. Hain TC, Helminski JO, Reis IL, Uddin MK: Vibration does not improve results of the
canalith repositioning procedure. Arch Otolaryngol Head Neck Surg 126:617–622, 2000.
18. Massoud EAS, Ireland DJ: Post-treatment instructions in the nonsurgical management of
benign paroxysmal positional vertigo. J Otolaryngol 25:121–125, 1996.
19. Nutti D, Nati C, Passali D: Treatment of benign paroxysmal positional vertigo: No need for
postmaneuver restrictions. Otolaryngol Head Neck Surg 122:440–444, 2000.
20. Gacek RR: Transection of the posterior ampulary nerve for relief of benign paroxysmal
positional vertigo. Ann Otol Rhinol Laryngol 83:596–605, 1974.
21. Parnes LS, McClure JA: Posterior semicircular canal occlusion in the normal hearing ear.
Otolaryngol Head Neck Surg 104:52–57, 1991.
22. Celebisov N, Bayam E, Gulec F, Kose T, Akyurekli O: Balance in posterior and horizontal
canal type benign paroxysmal positional vertigo before and after canalith repositioning
maneuvers. Gait Posture 29(3):520–523, 2009.
23. Baloh R, Honrubia V, Jacobson K: Benign positional vertigo: Clinical and oculographic
features in 240 cases. Neurology 37:371–378, 1987.
24. Nunez RA, Cass SP, Furman JM: Short- and long-term outcomes of canalith repositioning for
benign paroxysmal positional vertigo. Otolaryngol Head Neck Surg 122:647–652, 2000.
25. Radke A, Neuhauser H, von Brevern M, Lempert T: A modified Epley’s procedure for self-
treatment of benign paroxysmal positional vertigo. Neurology 53:1358–1360, 1999.
Case 8
Migraine-Related Dizziness

History

A 30-year-old man who worked as a bank teller presented with the chief complaint of
dizziness for 6 weeks. The patient dated his symptoms to discontinuation of fluoxetine,
which was being used for depression. He stated that he had discontinued it ‘‘to see if he
could do without his antidepressant medication.’’ The patient characterized his symptoms
as a constant sense of lightheadedness and disequilibrium that was exacerbated by head
movements and certain visual environments such as flickering lights and checkerboard
patterns. He had no complaints of hearing loss, tinnitus, aural fullness, abnormal vision,
weakness, loss of sensation, or incoordination. The patient stated that before he had started
taking fluoxetine 2 years prior to evaluation, he had also suffered from similar dizziness
complaints, although they were less severe. These previous symptoms included episodic
exacerbations, occasionally associated with headache.
Question 1: What are the diagnostic considerations in this case, and what further history
would be helpful?
Answer 1: This patient’s dizziness and disequilibrium are nonspecific and not parti-
cularly suggestive of a peripheral vestibular disorder, given their character and time
course. Many diagnostic considerations must be considered at this point in the
evaluation. However, clues to the patient’s diagnosis include the association with
discontinuation of an antidepressant, exacerbation by certain visual environments,
and a previous history of headache. Further history should be obtained regarding
precipitating factors and details of the history of headaches and their association
with dizziness. Also, a history of motion sickness in childhood and any family history
of a migrainous disorder would be helpful.

Additional History

When asked about the association between his dizziness and headache, the patient said that
during the previous 2 years he had suffered three or four episodes of severe unilateral
throbbing headache associated with nausea, lightheadedness, and disequilibrium that were
more severe than his symptoms now but similar in character. He noted that headaches were
more frequent before his treatment with an antidepressant and that most of his headaches
were associated with dizziness and disequilibrium. The patient had had motion sickness in

117
118 VESTIBULAR DISORDERS

childhood and continues to have motion sickness susceptibility. The patient’s family
history was significant; his mother and his paternal aunt had suffered from migraine
headaches.
Question 2: How does this additional history affect this patient’s diagnosis?
Answer 2: The characteristics of the patient’s headaches meet the International
Headache Society criteria for migraine headache.1 The temporal association
between migrainous symptoms and dizziness suggests a diagnosis of migraine-
related dizziness.2-4 A vestibulopathy unrelated to headaches is possible. Much less
likely are vertebrobasilar insufficiency or a craniovertebral junction abnormality. A
thorough examination and appropriate laboratory testing should be helpful in
establishing a diagnosis.

Question 3: In what ways can migraine manifest itself as dizziness and disequilibrium?
Answer 3: Migraine-related dizziness can present as a vertiginous aura preceding a
migraine headache in much the same way as positive visual phenomena or auras
such as scintillating scotomata and fortification spectra. Dizziness, disequilibrium,
and vertigo can occur during or following the resolution of a migraine-related
headache.
Some patients with migraine-related dizziness have migraine without headache,
also known as migraine equivalent, or dizziness separate from or instead of head-
aches. Some patients, like this one, may experience disequilibrium between head-
aches, that is, more or less constantly.5 This patient’s symptoms are typical of
migraine-related dizziness, which often include dizziness and disequilibrium exa-
cerbated by certain visual environments.

Question 4: What is the physiologic basis for the nausea and malaise associated with
migraine?
Answer 4: The vestibular system has powerful influences on the autonomic nervous
system, particularly the sympathetic nervous system, and on respiration.6
Vestibular activity can alter blood pressure and heart rate and can influence the
baroreflex. Vestibular inputs that are excessive or in conflict with other sensory
inputs can produce motion sickness,7 wherein individuals have a sense of malaise
associated with nausea, diaphoresis, and sometimes vomiting.
The mechanism whereby vestibular abnormalities, excessive vestibular stimula-
tion, and sensory mismatch induce motion sickness is unknown. Moreover, the
purpose of motion sickness is unknown. It is interesting that symptoms of postural
hypotension mimic some of the symptoms of vestibular system dysfunction. Possibly,
the vestibuloautonomic pathways are responsible for this overlap in symptoms.7

Physical Examination

The patient had normal general, neurologic, otologic, and neurotologic examinations.
Question 5: What laboratory testing, if any, would be helpful in establishing this patient’s
diagnosis?
Answer 5: There is no definitive laboratory test to diagnose migraine-related dizzi-
ness, which is a diagnosis of exclusion. Nothing in the patient’s history or the
physical examination suggests a structural neurologic abnormality; thus, brain
 CASE 8: MIGRAINE-RELATED DIZZINESS 119

imaging is not indicated at this point in the evaluation. Vestibular laboratory testing
might suggest an alternative diagnosis, as well as provide information regarding the
status of the patient’s balance system.
Audiometric testing should be performed to screen for asymmetric hearing loss
that may indicate the presence of a cerebellopontine angle or brainstem neoplasm
or hearing loss suggestive of endolymphatic hydrops.

LABORATORY TESTING

Videonystagmography: Ocular motor, positional, and caloric tests were normal.

Rotational testing revealed a right directional preponderance.
Posturography was normal.
The audiometric test was normal.
Vestibular evoked myogenic potentials were normal.
Question 6: What vestibular laboratory abnormalities have been described in patients with
migraine, and how can they be explained pathophysiologically?
Answer 6: The vestibular abnormalities that have been described in patients with
migraine include abnormalities on electronystagmography, rotational testing, and
posturography.8–12 Case 8: Table 1 indicates the percentage of patients with
migraine in our experience who have abnormal vestibular laboratory testing. By
far the most common abnormality noted was a directional preponderance on
rotational testing. The abnormalities in Case 8: Table 1 suggest a peripheral vestib-
ular component in some patients, such as those with a reduced vestibular response,
and a central vestibular abnormality in others, such as those with a directional
preponderance. A smaller but not insignificant number of patients with migraine-
related dizziness show either a spontaneous or a positional nystagmus or both.
Posturography abnormalities that can be ascribed to the vestibular system in
patients with migraine or related dizziness are uncommon.
The pathophysiology of the vestibular abnormalities in migraine-related dizzi-
ness is uncertain but may relate to similarities between pain pathways and vestib-
ular pathways.2

Case 8: Table 1 Most Common Patterns of Abnormalities on Vestibular Tests Including

Electronystagmography, Rotational Testing, and Posturography in Migraine-Related
Vestibulopathy (N = 100)

Pattern Percent

Normal 27
Isolated directional preponderance on rotation 22
Directional preponderance on rotation + reduced vestibular response 12
Directional preponderance on rotation + abnormal posturography 9
Directional preponderance on rotation + reduced vestibular response + 6
Abnormal posturography
Isolated reduced vestibular response 5
Isolated abnormal posturography 4
Source: With permission from Cass SP et al: Migraine-related vestibulopathy. Ann Otol Rhinol Laryngol
106:182–189, 1997.11
120 VESTIBULAR DISORDERS

Diagnosis/Differential Diagnosis

This patient’s diagnosis was migraine-related dizziness. His condition was exacerbated by
discontinuation of fluoxetine, which was apparently acting as an antimigrainous agent.

Treatment/Management

Question 7: What are the treatment options for a patient with migraine-related dizziness
and what factors should be considered?
Answer 7: The treatment options for patients with migraine-related dizziness are
outlined in Case 8: Table 2. First, it is necessary to educate the patient regarding the
association of dizziness with the underlying migrainous condition and the impor-
tance of avoiding of dietary triggers, such as tyramine-containing foods, alcohol,
and caffeine (see Case 17: Table 1), as well as avoiding stress and fatigue. Second,
the underlying migrainous condition should be treated with prophylactic medica-
tions, even if headaches are not currently prominent. Our experience is that a third
to half of patients respond favorably to each of the medications listed in Case 8:
Table 2. If the initial medication is unsuccessful, the other classes of agents should
be tried in turn. Third, if the most prominent vestibular symptom is movement-
associated disequilibrium, vestibular rehabilitation therapy is recommended.
Fourth, if the patient reports severe space and motion discomfort (see Chapter 7),
prescribe low-dose clonazepam. Finally, in patients with migraine-related dizziness
who also have panic attacks or agoraphobia, we obtain a psychiatric consultation
and rely on both behavioral therapy and specific medical therapy using antidepres-
sants or anxiolytic medications.
This patient was started on sertraline and advised regarding dietary restriction.
His symptoms of dizziness resolved.

Case 8: Table 2 Treatment Options for Migraine-Related Dizziness

1. Avoid dietary triggers

2. Treat underlying migraine phenomenon
• Antidepressants (e.g., sertraline 25–75 mg/day or amitriptyline 25–75 mg/day)
• Beta blockers (e.g., propranolol 80–320 mg/day)
• Calcium channel blockers (e.g., verapamil 80–120 mg/day)
• Anticonvulsants (e.g., valproic acid 250–1000 mg/day)
3. Treat movement-associated disequilibrium
• Vestibular rehabilitation therapy
4. Treat space and motion discomfort
• Clonazepam (0.25–0.5 mg/day)
5. Treat associated anxiety or panic disorder
• Behavioral therapy
• Pharmacotherapy
• Tricyclic antidepressants
• Anxiolytics (e.g., benzodiazepines)
Source: Adapted with permission from Cass SP et al: Migraine-related vestibulopathy. Ann Otol Rhinol
Laryngol,106:182–189,1997.11
 CASE 8: MIGRAINE-RELATED DIZZINESS 121

Summary

A 30-year-old man presented with dizziness and disequilibrium after discontinuation of an

antidepressant. There was a history of headache, and the patient’s complaints were con-
sistent with both migraine headache and migraine-related dizziness based on established
criteria. This diagnosis was further supported by a positive family history of migraine. The
patient was treated with introduction of an antidepressant, sertraline. This significantly
reduced his daily symptoms, although he continued to have migraine headaches associated
with dizziness approximately once every 6 months.

Teaching Points

1. Migraine-related dizziness should be suspected in patients with nonspecific

dizziness or vertigo associated with headache. A history of migraine headaches or a
positive family history of migraine increases the likelihood of this disease. Patients with
migraine-associated dizziness almost invariably report exacerbation of symptoms by
viewing certain moving visual environments or significant motion sickness sensitivity.
2. Migraine can manifest as dizziness and disequilibrium. Migraine-related dizziness
can present as a vertiginous aura preceding a migraine headache in much the same way as
positive visual phenomena or auras, such as scintillating scotomata and fortification
spectra. Dizziness, disequilibrium and vertigo can occur during a migraine headache.
Some patients with migraine-related dizziness have migraine without headache, also
known as migraine equivalent, that is, dizziness separate from or instead of headaches.
Some patients, like this one, may experience disequilibrium between episodes, that is, more
or less constantly. This patient’s symptoms are typical of migraine-related dizziness, which
often include dizziness and disequilibrium exacerbated by certain visual environments.
3. Vestibular laboratory abnormalities may be found in migraine-related dizziness. A
directional preponderance on rotational testing is the most common abnormality. Less
often, a unilateral caloric weakness, positional nystagmus, or spontaneous nystagmus
may occur.
4. Treatment options for patients with migraine-related dizziness are summarized in
Case 8: Table 2. First, the patient should be informed about the association of dizziness
with the underlying migrainous condition and the importance of avoiding dietary triggers
such as tyramine-containing foods, alcohol, and caffeine. Second, the underlying
migrainous condition should be treated with prophylactic antimigrainous medications
even if headaches are not currently prominent. Third, if the most prominent vestibular
symptom is movement-associated disequilibrium or unsteadiness, vestibular
rehabilitation therapy is recommended. Fourth, if the patient reports severe space and
motion discomfort, low-dose clonazepam should be prescribed. Finally, in patients with
panic attacks or agoraphobia, a psychiatric consultation should be obtained, and both
behavioral therapy and specific medical therapy using tricyclic antidepressants or
anxiolytic medications should be considered.

References
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1–140, 2004.
2. Furman, JM, Marcus DA, Balaban CD: Migrainous vertigo: Development of a pathogenetic
model and structured diagnostic interview. Curr Opin Neurol 16(1):5–13, 2003.
122 VESTIBULAR DISORDERS

3. Neuhauser H, Leopold M, von Brevern M, Arnold G, Lempert T: The interrelations of

migraine, vertigo, and migrainous vertigo. Neurology 56:436–441, 2001.
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1984.
6. Yates BJ, Miller AD, Lucot JB: Physiological basis and pharmacology of motion sickness: An
update. Brain Res Bull 47(5):395–406. 1998.
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8. Toglia JU, Thomas D, Kuritzky A: Common migraine and vestibular function:
Electronystagmographic study and pathogenesis. Ann Otol 90:267–271, 1981.
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10. Olsson J: Neurootologic findings in basilar migraine. Laryngoscope 101:1–41, 1991.
11. Cass SP, Ankerstjerne JDP, Yetiser S, Furman J, Balaban C, Aydogan B: Migraine-related
vestibulopathy. Ann Otol Rhinol Laryngol 106:182–189, 1997.
12. Vitkovic J, Paine M, Rance G: Neuro-otological findings in patients with migraine- and
nonmigraine-related dizziness. Audiol Neurootol 13(2):113–122, 2008.
Case 9
Meniere’s Disease—Medical
Management

History

A 35-year-old female attorney was evaluated 1 week after the onset of acute vertigo. About 1
month before evaluation, the patient noticed a sense of pressure or fullness in her right ear
similar to the feeling of water trapped in the ear after swimming. There was also a quiet
ringing in her ear, but within a few days the fullness and ringing disappeared. A few weeks
later these symptoms returned, and she also noticed difficulty hearing on the telephone with
the right ear. She went to a neighborhood urgent care center, where a mild ear infection was
diagnosed and treated with an oral antibiotic and a decongestant. A few days later, she woke
up with an aching pressure-like pain in the right ear associated with both increased ringing
and decreased hearing in the ear. Suddenly, she had an episode of acute vertigo that she
described as the environment whirling; it was associated with nausea and vomiting that lasted
for 3 hours. She was taken to an emergency room and given an intramuscular injection of an
antiemetic. The following day she felt nearly normal, with no vertigo. Her hearing loss,
ringing, and fullness in the right ear had almost completely resolved. Some disequilibrium
persisted. There was no significant medical history including no history of migraine headache
and nothing of medical significance in the family, including no family history of migraine.
Question 1: Based on the patient’s history, what is the likely cause of these symptoms?
Answer 1: This patient’s history suggests unilateral Meniere’s disease (see Cases 12,
20, 24, 42, and 41). Meniere’s disease is associated with recurrent vertigo and other
aural symptoms, such as tinnitus, hearing loss, and fullness or a pressure sensation
in the ear. The triad of episodic hearing loss, tinnitus, and vertigo are diagnostic of
Meniere’s disease.1
Question 2: What is the pathophysiology of Meniere’s disease? How does Meniere’s
disease produce episodic symptoms of hearing loss, tinnitus, aural fullness, and vertigo?
Answer 2: The mechanism underlying episodic hearing loss and vertigo caused by
Meniere’s disease is not entirely understood. However, a histological marker for
Meniere’s disease is endolymphatic hydrops which is a term used to describe a
particular pathologic condition of the inner ear characterized by swelling, or distension,
of the endolymphatic compartment of the inner ear (Case 9: Figure 1).2
Meniere’s disease produces transient and fully reversible inner ear dysfunction
early in the course of the disorder. Hearing loss, tinnitus, and aural fullness are
thought to be associated with endolymphatic hydrops and typically last for hours

123
124 VESTIBULAR DISORDERS

Case 9: Figure 1 Dilated utricle and saccule in endolymphatic hydrops.

Source: Reprinted by permission of the publisher from Schuknecht HF: Pathology of the Ear. Cambridge,
MA: Harvard University Press. Copyright 1974 by the President and Fellows of Harvard College.2

to weeks, whereas acute vertigo typically lasts for at least 20 minutes, usually 2 to 4
hours, and can be followed by a day or two of mild disequilibrium. The most popular
theory to explain the vertigo associated with Meniere’s disease is that endolymphatic
hydrops leads to rupture of the membranous labyrinth and subsequent potassium
intoxication of the vestibular hair cells.2,3 Normally, thin, delicate membranes, such
as Reissner’s membrane in the cochlea or the saccular membrane in the vestibule,
separate the endolymphatic space from the perilymphatic space. A rupture of these
membranes allows mixing of the high-potassium endolymph with the low-potas-
sium perilymph. The influx of a high concentration of potassium ions into the
perilymph can alter the neural discharge rate in the vestibular nerve, thereby causing
nystagmus and vertigo. The direction of nystagmus observed during an acute attack
of Meniere’s disease is variable and complex. In the few cases where eye move-
ments have been observed from the beginning of an attack, the slow component of
the nystagmus was initially directed away from the affected labyrinth, thus suggest-
ing abnormal excitatory neural activity in the affected ear. Seconds to minutes later,
the direction of nystagmus reversed, indicating abnormally reduced neural activity
in the affected labyrinth. This biphasic nystagmus response is consistent with the
results of animal models of potassium perfusion into the perilymph. A third phase of
nystagmus that beats toward the affected side, known as recovery nystagmus, also
can occur days to weeks later. Recovery nystagmus is presumably related to a
combination of central adaptation and recovery of vestibular function in the
affected labyrinth.4,5
The resolution of vertigo is probably the result of a combination of restoration of
normal potassium levels in the perilymph, normalization of the pressure–volume
relationships within the labyrinth following membrane rupture, and central vestib-
ular adaptation. Not uncommonly, hearing loss and aural fullness seem to improve
after the vertigo spell (Lermoyez syndrome); however, for unknown reasons, aural
fullness, tinnitus, and hearing loss generally follow a different, more protracted
course than the vertigo.
 CASE 9: MENIERE’S DISEASE—MEDICAL MANAGEMENT 125

Following repeated acute episodes, the previously reversible symptoms of

Meniere’s disease can become permanent and progressive. Hearing loss increases
and ceases to return to normal. Tinnitus becomes invariably present, and other
auditory distortions such as recruitment (sharp or loud sounds are perceived as
excessively loud, even painful) and diplacusis (a given tone is heard at a different
pitch in the two ears) become permanent. A permanent reduction of vestibular
function also occurs. These symptoms and signs are thought to be caused primarily
by progressive damage and loss of hair cells within the inner ear, not to direct
involvement of the primary afferent neurons of the labyrinth.

Physical Examination

Neurologic examination was normal. Otoscopic examination was normal. On tuning-fork

testing, Weber’s test showed lateralization to the left, and the Rinne test was positive
bilaterally. Mild diplacusis was noted. Neurotologic examination revealed no spontaneous
nystagmus, a normal head thrust, and a left-beating nystagmus following head shake, normal
Dix-Hallpike maneuvers, and normal sway while standing on foam with the eyes closed.
Question 3: Are the findings on this physical examination consistent with a presumptive
diagnosis of Meniere’s disease (endolymphatic hydrops)? Can the affected side be determined
from this examination?
Answer 3: In patients with vestibular system dysfunction localized to the inner ear,
the neurologic examination should be normal, as was found in this patient. The
tuning-fork testing suggests a sensorineural hearing loss in the right ear. The
patient’s ability to stand on foam with her eyes closed indicates nearly full recovery
of postural control. The nystagmus following head shake and the positive result on
the stepping test, however, indicate a residual vestibular system asymmetry.
Endolymphatic hydrops characteristically produces reversible changes in the inner
ear. Thus, the findings on neurotologic examination depend upon when the most
recent episode of vertigo occurred, because vestibular compensation (see
Chapter 1) acts to reduce the symptoms and signs of any persistent peripheral
vestibular injury. Immediately after an abrupt decrease in vestibular function,
patients usually march on the stepping test toward the side of the affected ear.
However, days to weeks following an acute spell of vertigo, patients often march
toward the contralateral ear on the stepping test, suggesting that the combined
influence of increasing vestibular function in the diseased ear and vestibular com-
pensation is producing relative overcompensation. Thus, the physical examination
of this patient supports the preliminary diagnosis of endolymphatic hydrops affect-
ing the right ear. The diminished hearing in the right ear provides the best clue to
localization, whereas the post-head-shake nystagmus and abnormal stepping test
suggest a recent unilateral vestibular injury.
Question 4: What causes Meniere’s disease?
Answer 4: Meniere’s disease is thought to be associated with endolymphatic
hydrops, which represents a common pathologic response to a variety of insults
to the inner ear. Etiologic factors include, but are not limited to, concurrent or
preceding viral infection of the inner ear, head trauma, vascular insufficiency, syphilis,
autoimmune inner ear disease, abnormal glucose metabolism, hypothyroidism,
and inhalant and food allergies.6
126 VESTIBULAR DISORDERS

The use of the terms Meniere’s disease and endolymphatic hydrops can be confusing.
Many prefer to define Meniere’s disease as the idiopathic syndrome of endolymphatic
hydrops. When the cause of endolymphatic hydrops is considered secondary to
another disorder it is often designated more sepcifically, for example, as syphilitic
endolymphatic hydrops, autoimmune-related endolymphatic hydrops, and so on.
In addition to these etiologic factors, other factors thought to influence or
aggravate the formation of endolymphatic hydrops include excessive salt intake,
stress, and excessive caffeine ingestion.
Question 5: Which laboratory studies should be ordered for this patient and why?
Answer 5: The patient’s history and physical examination are both consistent with a
peripheral vestibular disorder. Quantitative vestibular testing and audiometric testing
should be performed to substantiate the diagnosis and to determine the affected side.

Laboratory Testing

Videonystagmography: Ocular motor and positional tests were normal. Caloric testing
demonstrated a 35% reduced vestibular response in the right ear.
VEMPs were reduced on the right.
Audiometric testing (Case 9: Figure 2) revealed a unilateral low-frequency sensor-
ineural hearing loss affecting the right ear. Hearing in the left ear was normal.
250 500 1000 2000 4000 8000

–10 –10

0 0
10 10
20 20
30 30
Hearing Level in dB

40 40
50 50
60 60

70 70
80 80
90 90
100 100

110 110

250 500 1000 2000 4000 8000

Frequency in Hz

Right Left
Word Recognition Score unmasked
Air masked
Right : 100%
Left : 100% Bone unmasked
masked

Case 9: Figure 2 Audiogram.

 CASE 9: MENIERE’S DISEASE—MEDICAL MANAGEMENT 127

Electrocochleography revealed a summating to action potential ratio of 60% in the

right ear and 20% in the left ear (see Chapter 5).
Imaging: An MRI scan of the brain was normal.
Other tests: A metabolic blood screen consisting of a complete blood count, an
erythrocyte sedimentation rate, an autoimmune panel, thyroid function tests, and the
fluorescent treponemal antibody absorption test (FTA-ABS) was normal.
Question 6: Why was an MRI scan performed?
Answer 6: Although the constellation of clinical symptoms is characteristic of
Meniere’s disease, tumors of the cerebellopontine angle, such as meningioma or
acoustic neuroma, can cause similar symptoms, including fluctuating hearing loss,
aural fullness, tinnitus, and dizziness. Thus, it is prudent to perform a central
nervous system scan in cases of asymmetric hearing loss.

Diagnosis/Differential Diagnosis

This patient was given a diagnosis of Meniere’s disease, or endolymphatic hydrops,

affecting the right ear.

Additional History

Further evaluation of the patient’s lifestyle and habits revealed a stressful work environ-
ment that included a 10- to 12-hour workday and occasional all-nighters. In addition, the
patient consumed approximately six cups of caffeinated coffee per day. Other habits that
could exacerbate endolymphatic hydrops included a high-salt diet and smoking one pack of
cigarettes per day.

Treatment/Management

Question 7: What medications have been shown to be efficacious in the treatment of

Meniere’s disease?
Answer 7: Several controlled clinical trials have demonstrated the efficacy of the
combination of a low-salt diet and a diuretic in the treatment of Meniere’s disease.7
The combination of hydrochlorothiazide and triamterene is widely accepted as the
first choice of diuretic.8 Oral vasodilators such as nicotinic acid and parenteral
treatments such as histamine injections or papaverine have not been tested in
clinical trials of endolymphatic hydrops.9 However, based on anecdotal experiences,
these medications are frequently prescribed for this condition.
Acute attacks of vertigo can be treated with antiemetic and vestibular-suppres-
sant medications. Promethazine (25 to 50 mg) or compazine (10 mg) (oral or as a
rectal suppository) are effective for mild to moderate nausea and vomiting.
Meclizine (25 mg) is helpful for mild dizziness but is not generally effective for
severe nausea or vomiting. Vestibular rehabilitation is not generally helpful in
Meniere’s disease because the vertigo usually occurs abruptly and remits sponta-
neously, and most individuals report normal balance between episodes.
The initial treatment recommendations for the patient included a prescription for
hydrochlorothiazide and triamterene once daily, alteration of the patient’s lifestyle to
128 VESTIBULAR DISORDERS

include a low-salt diet, a reduction in the use of caffeine, reduced smoking, and stress
reduction.

Follow-Up

The patient was compliant with treatment, and she became symptom-free aside from
persistent mild hearing loss and tinnitus. No major episodes of vertigo recurred.

Summary

A 35-year-old female attorney presented with fluctuating aural fullness, hearing loss, and
tinnitus followed by an episode of acute prostrating vertigo. The presumptive diagnosis of
Meniere’s disease was made on the basis of these clinical symptoms. An audiogram,
electrocochleography, vestibular laboratory testing, and MRI scanning were performed
to further evaluate and confirm the diagnosis. The patient was treated with a diuretic and a
salt-restricted diet. This resulted in a significant reduction in her symptoms.

Teaching Points

1. The typical presentation of Meniere’s disease includes fluctuating aural fullness,

tinnitus, hearing loss, and recurrent bouts of vertigo. Endolymphatic hydrops
(swelling of the endolymphatic space) is an associated histologial marker that may
reflect the underlying pathophysiologic process of Meniere’s disease.
2. Meniere’s disease can be associated with a number of metabolic, infectious, and
autoimmune disorders. Meniere’s disease is often defined as the idiopathic
endolymphatic hydrops. Secondary endolymphatic hydrops is designated more
specifically.
3. The mechanisms of hearing loss and vertigo caused by Meniere’s disease are
uncertain. Possibly, Meniere’s disease is related to endolymphatic hydrops, which
may cause rupture of intralabyrinthine membranes and mixing of endolymph and
perilymph with concomitant potassium intoxication.
4. The medical treatment of Meniere’s disease includes the combination of a diuretic,
typically of hydrochlorothiazide plus triamterene, and dietary salt restriction.

References
1. Radtke A, von Brevern M, Feldmann M, Lezius F, Ziese T, Lempert T, Neuhauser H:
Screening for Meniere’s disease in the general population—the needle in the haystack. Acta
Otolaryngol 128(3):272–276, 2008.
2. Schuknecht HF: Pathology of the Ear. Cambridge, MA: Harvard University Press, 1974.
3. Brown DH, McClure JA, Downar-Zapolski Z: The membrane rupture theory of Meniere’s
disease—is it valid? Laryngoscope 98:599–601, 1988.
4. McClure JA, Copp JC, Lycett P: Recovery nystagmus in Meniere’s disease. Laryngoscope
91:1727–1737, 1981.
5. Bance M, Mai M, Tomlinson D, Rutka J: The changing direction of nystagmus in acute
Meniere’s disease: Pathophysiological implications. Laryngoscope 101:197–201, 1991.
 CASE 9: MENIERE’S DISEASE—MEDICAL MANAGEMENT 129

6. Paparella MM: The cause (multifactorial inheritance) and pathogenesis (endolymphatic

malabsorption) of Meniere’s disease and its symptoms (mechanical and chemical). Acta
Otolaryngol (Stockh) 99:445–451, 1985.
7. Coelho DH, Lalwani AK: Medical management of Meniere’s disease. Laryngoscope
118(6):1099–1108, 2008.
8. Jackson CG, Glasscock ME, Davis WE: Medical management of Meniere’s disease. Ann Otol
90:142–147, 1981.
9. Cass SP: Role of medications in otological vertigo and balance disorders. Semin Hearing
12:257–269, 1991.
Case 10
Disequilibrium of Aging

History

An 80-year-old woman presented with a complaint of disequilibrium when walking. The

patient noted occasional lightheadedness but had no complaint of vertigo, hearing loss, or
tinnitus. She did not complain of positional sensitivity when lying supine. Her symptoms
had been present for several years but had been especially noticeable in the last 6 months.
The patient dated the onset of her problem to cataract surgery in the right eye that resulted
in a marked improvement in her vision. The patient’s family confirmed that her balance
had been gradually worsening for several years, and she had become more sedentary.1 Her
primary care physician ordered a computed tomography (CT) scan of the head, which
revealed a small (0.5 cm) meningioma in the falx cerebri without evidence of a mass effect.
A magnetic resonance imaging (MRI) scan confirmed this finding and revealed diffuse
increased signal intensity in the deep white matter. The patient was using meclizine, 25 mg
twice daily, without obvious benefit.
Question 1: Based on this patient’s history, what are the diagnostic considerations, and
what further information would be helpful in her evaluation?
Answer 1: This patient’s history suggests a nonspecific abnormality of the balance
system. With the information available, it is difficult to localize the problem to the
vestibular system. Further information regarding the patient’s medical history,
medication use, any remote history of a vestibular disorder, family history, and
habits such as smoking and alcohol consumption would all be helpful. Additionally,
a physical examination is likely to provide helpful information.

Additional History

The patient had a history of essential hypertension for the past 20 years and was being
treated with a diuretic. There was no remote history of dizziness or disequilibrium. The

130
 CASE 10: DISEQUILIBRIUM OF AGING 131

patient had smoked one pack of cigarettes per day for 40 years but had quit 15 years ago and
consumed about one ounce of ethanol daily.
The patient has no family history of balance disorder.

Physical Examination

The patient’s general examination was normal. Neurologic examination revealed no

specific abnormalities of cranial nerves aside from difficulty pursuing a slowly moving
target. Examination of the motor and sensory systems was normal. Coordination was
normal. However, the patient had a slightly widened base to her gait. Otologic examination
was normal. Neurotologic examination was normal, except that she was quite unsteady on a
compliant foam surface with the eyes open or eyes closed, but she did not fall.

Question 2: Based on the history and physical examination, what is this patient’s likely
diagnosis? What laboratory tests might assist in making the diagnosis?
Answer 2: This patient has no obvious cause for disequilibrium, although several
factors might be contributing, including age, probable atherosclerotic disease
considering the risk factors of hypertension and tobacco use, recent cataract
surgery that changed her vision, and a diminished level of activity.
Further information from laboratory tests may be helpful. Vestibular labora-
tory testing would provide information regarding the presence of a vestibular
system abnormality. An MRI scan has already been performed. The patient was
found to have evidence of small-vessel disease. Her small falcine meningioma
is probably asymptomatic. If not already assessed by the patient’s primary care
physician, her metabolic, hematologic, and thyroid status should
be determined.

Laboratory Testing

Videonystagmography: Ocular motor testing revealed difficulty performing smooth

pursuit. There was a direction-changing positional nystagmus of 4 degrees per second,
which was considered borderline abnormal for an 80-year-old patient. Caloric irrigations
revealed absent responses to bithermal stimulation and symmetrically reduced responses to
ice water irrigations.
Rotational testing revealed responses of normal magnitude and symmetry with an
increased phase lead. Trapezoidal rotations revealed a somewhat shortened time constant.
Posturography testing indicated excessive sway in a nonspecific pattern. Also, the patient
had an inability to adapt to repeated platform rotations.
VEMPs were mildly reduced bilaterally.
Audiometric testing revealed a mild sensorineural hearing loss, worse at higher fre-
quencies, which was seen bilaterally.
MRI scanning of the brain revealed diffuse nonspecific deep white matter disease on T2
FLAIR imaging (Case 10: Figure 1).
Vestibular laboratory test results suggest a nonspecific central vestibular, possibly
cerebellar, abnormality because of the abnormally small caloric responses and VEMPs
and abnormal timing of rotational responses. The MRI findings also are nonspecific. These
findings may be an effect of age.
132 VESTIBULAR DISORDERS

Case 10: Figure 1 Magnetic resonance image of white matter lesions in a patient with
disequilibrium of aging.
Source: With permission from Baloh RW, Yue Q, Socotch TM, Jacobson KM: White matter lesions and
disequilibrium in older people. I. Case-control comparisons. Arch Neurol 52(10):970–974, 1995. 4

Diagnosis/Differential Diagnosis

Question 3: Based on the information available, what is this patient’s likely diagnosis?
Answer 3: The patient’s disequilibrium cannot be ascribed to a single causative
factor. Such older patients with deep white matter disease have been given a
diagnosis of ‘‘disequilibrium of aging,’’ ‘‘presbyastasis,’’ and ‘‘disequilibrium of the
elderly.’’2,3,4,5
Presumably, such patients have disequilibrium caused primarily by abnormal
sensory processing by the central nervous system and abnormal control mechan-
isms for balance. Their problem is worsened by abnormal sensory signals, an aged
musculoskeletal system with a concomitant decreased range of motion, and dimin-
ished strength.
Question 4: What is the influence of age on vestibular function?
Answer 4: Although balance function is known to be adversely affected by aging,
manifested by an increase in the incidence of falls in the elderly,6 the cause of this
decline is not known. Many structures in the peripheral vestibular system are known to
be affected by increased age. Specifically, vestibular hair cell degeneration,7 saccular
otoconia degeneration,8 changes in vestibular hair cell synaptic membranes,9 a decline
in the number of vestibular ganglion cells,10 and a decline in the number of vestibular
fibers11 are all associated with increased age. Aging also influences central vestibular
function. There are modest changes in vestibulo-ocular function;12,13,14,15 a reduc-
tion in the ability to combine visual and vestibular signals, that is, impaired visual–
vestibular interaction; and a preserved ability to modify (adapt) vestibular reflexes in
response to altered visual input. 13 Postural sway also increases with advanced age,
 CASE 10: DISEQUILIBRIUM OF AGING 133

Case 10: Table 1 Possible Strategies for Fall Prevention for Persons with Disequilibrium of Aging

Perform balance exercises27,30

Focus on one task at a time while walking18,25
Make home modifications and reinforce safe home behaviors (e.g., ramps, rails, grab bars, etc.)20,29,30
Identify and treat postural hypotension17
Increase gait speed26
Investigate and remedy low bone density findings
Modify clothing to reduce trip hazards
Review medications,17 especially benzodiazepines and psychotropic medications
Improve strength17,30
Perform Tai Chi28,31
Use an assistive device19
Use hip pads21
Visual aids (e.g., glasses, enhanced light, taking glaucoma medication)22,23,24

particularly under circumstances that require vestibular sensation such as standing

on a compliant surface with a distorted visual surround.16
This patient was given a diagnosis of disequilibrium of aging.

Treatment/Management

This patient was enrolled in a vestibular rehabilitation therapy program that emphasized
gait training. Vestibular-suppressant medications were discontinued as they may cause
decreased vestibular sensitivity and a concomitant reduction in stability. The patient’s
disequilibrium improved slightly. Case 10: Table 1 provides ideas for intervention for
persons presenting with a diagnosis of disequilibrium of aging.

Summary

An 80-year-old woman presented with gradually worsening balance during walking without
specific complaints of vertigo. The patient had a medical history of hypertension. Physical
examination did not suggest a specific localization for her disequilibrium. Laboratory
studies suggested cerebrovascular disease and nonspecific vestibular system impairment.
A diagnosis of disequilibrium of aging was given. Treatment consisted of discontinuation
of vestibular-suppressant medications and vestibular rehabilitation therapy.

Teaching Points

1. Aging affects the vestibular system. In the vestibular periphery, otoconia, hair cells,
and ganglion cells and nerve fibers degenerate with increasing age. Centrally, there is a
decline in vestibular processing that includes a reduction in the ability to combine visual
and vestibular signals and a decline in the ability to modify (adapt) vestibular reflexes.
2. Disequilibrium of aging, also known as presbyastasis, is a term used to describe the
condition of elderly patients who present with imbalance and disequilibrium that
cannot be ascribed to a particular disease state or to a single causative factor. White
matter lesions on MRI scans have been associated with this condition. Presumably, such
134 VESTIBULAR DISORDERS

patients have disequilibrium based on abnormal sensory input, abnormal sensory

processing by the central nervous system, abnormal control mechanisms for balance,
and an aged musculoskeletal system with a concomitant decreased range of motion and
diminished strength.
3. Vestibular rehabilitation therapy may benefit patients with disequilibrium of
aging.
4. Patients with disequilibrium of aging should be counseled regarding prevention of
falls, including use of a cane if necessary, and the use of appropriate home safety
devices such as rails in the bathroom.

References
1. Gazzola JM, Gananca FF, Aratani MC, Perracini MR, Gananca MM: Circumstances and
consequence of falls in elderly people with vestibular disorders. Braz J Otorhinolaryngol
72(3):388–392, 2006.
2. Jenkins HA, Furman JM, Gulya AJ, Honrubia V, Linthicum FH, Mirka A: Disequilibrium of
aging. Otolaryngol Head Neck Surg 100:272–282, 1989.
3. Belal A, Glorig A: Disequilibrium of ageing (presbyastasis). J Laryngol Otol 100:1037–1041,
1986.
4. Baloh RW, Yue Q, Socotch TM, Jacobson KM: White matter lesions and disequilibrium in
older people. I. Case-control comparisons. Arch Neurol 52(10):970–974, 1995.
5. Whitman GT, Tang T, Lin A, Baloh RW: A prospective study of cerebral white matter
abnormalities in older people with gait dysfunction. Neurology 57(6):990–994, 2001.
6. Tinetti ME, Speechley M, Ginter SG: Risk factors for falls among elderly persons living in the
community. N Engl J Med 319:1701–1707, 1988.
7. Rosenhall U, Rubin W: Degenerative changes in the human vestibular sensory epithelia. Acta
Otolaryngol 79:67–80, 1975.
8. Ross MD, Peacor D, Johnsson LG, Allard LF: Observations on normal and degenerating
human otoconia. Ann Otol 85:310–326, 1976.
9. Engstrom H, Ades HW, Engstrom B, Gilchrest D, Bourne G: Structural changes in the
vestibular epithelia in elderly monkeys and humans. Adv Otorhinolaryngol 22:93–110, 1977.
10. Richter, E: Quantitative study of human Scarpa’s ganglion and vestibular sensory epithelia.
Acta Otolaryngol 90:199–208, 1980.
11. Bergstrom B: Morphology of the vestibular nerve. II. The number of myelinated vestibular
nerve fibers in man at various ages. Acta Otolaryngol 76:173–179, 1973.
12. Baloh RW, Jacobson KM, Socotch TM: The effect of aging on visual-vestibuloocular
responses. Exp Brain Res 95:509–516, 1993.
13. Paige GD: Senescence of human visual–vestibular interactions. J Vestib Res 2:133–151, 1992.
14. Peterka R, Black F, Schoenhoff M: Age-related changes in human vestibulo-ocular reflexes:
Sinusoidal rotation and caloric tests. J Vestib Res 1:49–59, 1990.
15. Furman JF, Redfern MS: Effect of aging on the otolith-ocular reflex. J Vestib Res 11:91–103,
2001.
16. Peterka R, Black F: Age-related changes in human posture control: Sensory organization tests.
J Vestib Res 1:73–85, 1990.
17. Guideline for the prevention of falls in older persons. American Geriatrics Society, British
Geriatrics Society, and American Academy of Orthopaedic Surgeons Panel on Falls
Prevention. J Am Geriatr Soc 49(5):664–672, 2001.
18. Chen HC, Schultz AB, Giordani B, Alexander NB, Guire KE: Stepping over obstacles:
Dividing attention impairs performance of old more than young adults. J Gerontol A Biol Sci
Med Sci 51(3):M116–22, 1996.
19. Jeka JJ: Light touch contact as a balance aid. Phys Ther 77(5):476–487, 1997.
20. Johnson M, Cusick A, Chang S: Home-screen: A short scale to measure fall risk in the home.
Public Health Nurs 18(3):169–177, 2001.
 CASE 10: DISEQUILIBRIUM OF AGING 135

21. Kannus P, Parkkari J, Niemi S, Pasanen M, Palvanen M, Jarvinen M, Vuori I: Prevention of

hip fracture in elderly people with use of a hip protector. N Engl J Med 343(21):1506–1513,
2000.
22. Lord SR, Dayhew J: Visual risk factors for falls in older people. J Am Geriatr Soc 49(5):508–
515, 2001.
23. Lord SR and Menz HB: Visual contributions to postural stability in older adults. Gerontology
46(6): 306–310, 2000.
24. Lord SR, and Webster IW: Visual field dependence in elderly fallers and non-fallers. Int J
Aging Hum Dev 31(4):267–277, 1990.
25. Lundin-Olsson L, Nyberg L, Gustafson Y: ‘‘Stops walking when talking’’ as a predictor of
falls in elderly people. Lancet 349(9052):617, 1997.
26. Montero-Odasso M, Schapira M, Soriano ER, Varela M, Kaplan R, Camera LA, Mayorga
LM: Gait velocity as a single predictor of adverse events in healthy seniors aged 75 years and
older. J Gerontol A Biol Sci Med Sci 60(10):1304–1309, 2005.
27. Province MA, Hadley EC, Hornbrook MC, Lipsitz LA, Miller JP, Mulrow CD, Ory MG,
Sattin RW, Tinetti ME, Wolf SL: The effects of exercise on falls in elderly patients. A
preplanned meta-analysis of the FICSIT Trials. Frailty and Injuries: Cooperative Studies of
Intervention Techniques. JAMA 273(17):1341–1347, 1995.
28. Richerson S, K Rosendale: Does Tai Chi improve plantar sensory ability? A pilot study.
Diabetes Technol Ther 9(3):276–286, 2007.
29. Sattin RW, Rodriguez JG, DeVito CA, Wingo PA: Home environmental hazards and the risk
of fall injury events among community-dwelling older persons. Study to Assess Falls among
the Elderly (SAFE) Group. J Am Geriatr Soc 46(6):669–676, 1998.
30. Tinetti ME: Clinical practice. Preventing falls in elderly persons. N Engl J Med 348(1):42–49,
2003.
31. Wolf SL, Barnhart HX, Kutner NG, McNeely E, Coogler C, Xu T: Reducing frailty and falls in
older persons: An investigation of Tai Chi and computerized balance training. Atlanta FICSIT
Group. Frailty and Injuries: Cooperative Studies of Intervention Techniques. J Am Geriatr Soc
44(5):489–497, 1996.
Case 11
Multisensory Disequilibrium

History

A 55-year-old man who owned a clothing store presented with the chief complaint of
disequilibrium. The patient dated the onset of his problem to a vertiginous episode
experienced 6 months before evaluation. Since that time, he had noted difficulty with
ambulation, especially in dimly lit environments, and great difficulty while trying to
shower. He had no complaint of vertigo since recovery from the single vertiginous episode
6 months before evaluation and no complaints of hearing loss or tinnitus. The patient did
not report positional sensitivity.
The patient’s history was significant for insulin-dependent diabetes mellitus for 10
years. There was no family history of a balance problem.
Question 1: Based on the history provided, what are the diagnostic considerations, and
what further historical information would be helpful in reaching a diagnosis?
Answer 1: This patient’s history is consistent with a balance system abnormality. A
diagnostic consideration is residual dysfunction from his vertiginous episode 6
months previously. The patient’s lack of vertigo and difficulty with ambulation
suggest that he may not have compensated for a peripheral vestibular loss (see
Case 1). Also, his diabetes mellitus may have caused visual loss, proprioceptive loss,
or both. Thus, along with vestibular dysfunction, the patient may be suffering from
a combination of sensory deficits. He should be asked about diabetic retinopathy,
any symptoms suggestive of a peripheral neuropathy, and more details of the
vertiginous episode 6 months before presentation.

Additional History

The patient’s vertiginous episode 6 months previously was associated with the acute onset
of vertigo, nausea, and vomiting. He had severe gait ataxia and was bedridden for nearly a
day. The patient did not require hospitalization or intravenous hydration despite his insulin-
dependent diabetes mellitus, but he was nauseated and had a poor appetite for 3 days, after
which he noticed disequilibrium when walking. His gait instability improved somewhat;
by 2 weeks after the acute vertiginous episode, his symptoms had stabilized but were still
present. He was evaluated by his primary care physician, was told that he had ‘‘labyrinthitis,’’
and was given meclizine. The meclizine provided symptomatic relief of dizziness for the

136
 CASE 11: MULTISENSORY DISEQUILIBRIUM 137

first month after the vertiginous episode. Because the medication caused him to feel
lethargic, he self-discontinued its use, with no worsening of his dizziness or imbalance.
The patient had required laser treatments in both eyes in the past for diabetic retinopathy
but had not required such treatment in the last year. He also reported numbness and tingling in
both feet that was more or less constant but was especially noticeable when he was cold. The
patient also occasionally had a sense of burning in the feet that was annoying when he was
trying to fall asleep. He was using gabapentin, 100 mg three times daily, for this complaint.

Physical Examination

The patient had a normal general examination without postural hypotension. Funduscopic
examination revealed evidence of diabetic nonproliferative retinopathy. On neurologic exam-
ination, extraocular movements were full, without nystagmus. On neurotologic examination,
no nystagmus was seen with infrared goggles. Motor system examination and coordination
were normal. Decreased vibratory sensation below the knee bilaterally was noted. The patient
made several errors during assessment of joint position in both feet. Ankle jerks were absent.
His gait was wide-based, and he was very cautious when walking. He did not veer to the right
or to the left. Romberg’s test was negative. Otologic examination was normal.
However, the patient could not stand on a compliant foam surface with his eyes open or
closed.

Laboratory Testing

Videonystagmography revealed no spontaneous or positional nystagmus. Caloric testing

revealed absent responses during alternate bithermal testing on the left, with reduced
responses of 6 degrees per second peak velocity for both warm and cold irrigation on the
right. Ice-water irrigation of the left ear revealed that responses were present but markedly
reduced. Ice-water irrigation of the right ear was not performed because the bithermal
responses were considered normal.
Rotational testing revealed symmetric responses of reduced magnitude with an increased
phase lead at low frequency (0.02 and 0.05 Hz) and a short time constant of 9 seconds.
Posturography indicated excessive sway on conditions 4, 5, and 6, that is, a surface
dependence pattern (see Chapter 4).
Vestibular-evoked myogenic potentials were reduced bilaterally.
Audiometric testing showed a bilateral sensorineural hearing loss of mild to moderate
degree that was worse at the high frequencies. Word recognition was well preserved bilaterally.
MRI scanning of the brain showed nonspecific periventricular white matter changes.
Question 2: How does the information from the physical examination alter the diagnostic
considerations in this case?
Answer 2: The physical examination suggests that the patient has diabetic retino-
pathy and a peripheral neuropathy, probably the result of diabetes. On examina-
tion, the patient had no evidence of an ongoing vestibular asymmetry, with no
spontaneous nystagmus and no veering of gait. Thus, although impaired sensation
other than vestibular function predisposes to impaired compensation, the patient’s
physical examination does not suggest poor compensation. Rather, he may be
suffering from the combined effects of loss of several sensory modalities that are
important for balance.
138 VESTIBULAR DISORDERS

Diagnosis/Differential Diagnosis

Question 3: Based on the history, physical examination, and laboratory tests, what is this
patient’s likely diagnosis?
Answer 3: This patient is likely to be suffering from multisensory disequilibrium1
caused by diabetes mellitus. He has a history consistent with an acute vestibular
syndrome, possibly from diabetic vascular disease, with involvement of either the
vestibular labyrinth or the vestibular nerve. Laboratory testing confirms a bilateral
reduction that is worse on the left. The history of tingling and burning paresthesias,
decreased sensation in the feet, and absent ankle jerks supports the conclusion that
a peripheral neuropathy exists.
Question 4: What is multisensory disequilibrium? In what clinical settings is it often seen?
Answer 4: Multisensory disequilibrium is a condition wherein a patient is suffering
from dysfunction in all three of the sensory systems most important for balance,
that is, vestibular, visual, and somatic and proprioceptive sensation. Such patients
typically complain of unstable gait worsened by environments that further impair or
distort their sensory input, such as dimly lit environments, slanted surfaces, soft or
compliant surfaces, heights, or moving surfaces such as walkways or escalators.2
Like patients with vestibular system abnormalities, those with multisensory dis-
equilibrium may find it helpful to lightly touch a wall or furniture while standing or
walking indoors or lightly touch a companion while walking outdoors. Such
patients also may benefit from carrying a straight cane, which can provide supple-
mental proprioceptive information regarding spatial orientation through the upper
extremities.
Multisensory disequilibrium is most commonly seen in patients with diabetes
mellitus because the disease can cause vestibulopathy, retinopathy, and peripheral
neuropathy. In addition to diabetes, multisensory disequilibrium can be seen with
any combination of disorders that impair all three sensory modalities that are
important for balance.
This patient was given a diagnosis of multisensory disequilibrium due to diabetes
mellitus.

Treatment/Management

Question 5: What is the treatment of patients with multisensory disequilibrium?

Answer 5: The treatment of patients with multisensory disequilibrium is aimed at
increasing the amount of sensory input available and training such patients how to
best use their remaining sensory inputs to control balance. Vestibular-suppressant
medications should be discontinued. Refractive errors should be corrected. If
patients have cataracts, they should be evaluated by an ophthalmologist for possible
surgery. Bifocals and trifocals should be avoided. A cane or rolling walker should be
prescribed for patients with multisensory disequilibrium to add to their somatosensory
input. Medication use should be scrutinized for the presence of any agents known
to impair central nervous system function, and these medications also should be
discontinued if possible (see Chapter 8).
Ergonomic factors should be optimized, including proper footwear, night lights
in the home, removal of throw rugs, installation of handrails and grab bars, and a
 CASE 11: MULTISENSORY DISEQUILIBRIUM 139

rubber bath mat. Also, these patients should be referred for vestibular rehabilitation
therapy, including gait training (see Chapter 6).
This patient was advised not to use meclizine or any other vestibular-suppressant
medication. A cane was prescribed for him, and he was referred for a course of
vestibular rehabilitation therapy. With these measures, his disequilibrium improved
somewhat.

Summary

A 55-year-old man with a history of diabetes mellitus presented with a complaint of

disequilibrium that had persisted for 6 months after a vertiginous episode. Physical
examination suggested evidence of diabetic retinopathy and peripheral neuropathy.
Laboratory testing confirmed the presence of a bilateral peripheral vestibular loss coupled
with a vestibular asymmetry. The patient was given the diagnosis of multisensory dis-
equilibrium. Treatment consisted of discontinuation of vestibular-suppressant medication,
the use of a cane, enrollment in a course of vestibular rehabilitation therapy, and counseling
regarding the benefit of using proper footwear, night lights in the home, removal of throw
rugs, installation of handrails and grab bars, and a rubber bath mat.

Teaching Points

1. The three sensory systems most important for balance are vestibular, visual, and
somatic-proprioceptive sensation.
2. Multisensory disequilibrium is a combined dysfunction of vestibular, visual, and
somatic-proprioceptive sensation. Patients with multisensory disequilibrium
typically complain of unstable gait worsened by environments that further impair or
distort their sensory input, such as dimly lit environments, slanted surfaces, soft or
compliant surfaces, or moving surfaces such as walkways or escalators.
3. Diabetes mellitus is a common cause of multisensory disequilibrium because the
disease can cause vestibulopathy, retinopathy, and/or peripheral neuropathy. In
addition to diabetes, multisensory disequilibrium can be seen with any combination of
disorders that impair all three sensory modalities important for balance, such as a
combination of peripheral vestibulopathy, impaired vision from cataracts, and
peripheral neuropathy.
4. Supplemental proprioceptive information regarding spatial orientation via the
upper extremities may benefit patients with multisensory disequilibrium. Patients
often find it helpful to lightly touch a wall or furniture while standing or walking indoors
or to touch a companion while walking outdoors. Such patients also may benefit from
carrying a walking stick.
5. The treatment of multisensory disequilibrium is aimed at increasing the amount of
sensory input available and training patients how to best use their remaining
sensory inputs to control balance.

Reference
1. Drachman DA, Hart CW: An approach to the dizzy patient. Neurology 22:323–334, 1972.
2. Brandt T, Daroff R: The multisensory physiological and pathological vertigo syndromes. Ann
Neurol 7:195–203, 1980.
Case12
Meniere’s Disease—
Nonablative Management of
the Medically Refractory
Patient

History

A 60-year-old female real estate agent presented with a 1-year history of fluctuating right-
sided hearing loss associated with ear pressure, tinnitus, and episodic vertigo. Symptoms
began with a sudden change in hearing and fullness in the right ear. She was treated initially
for possible eustachian tube dysfunction but several months later an episode of severe acute
vertigo occurred prompting reevaluation. Her primary care physician now suspected
Meniere’s disease and started her on a salt-restricted diet and diuretic. After 6 months of
ongoing symptoms, referral for specialty care was made. Currently she reports that the
hearing in her ear right fluctuates but never returns to normal. She reports no symptoms in
her left ear. Episodes of vertigo are variable, sometimes very severe and incapacitating,
lasting hours, but most often vertigo is less severe. Severe episodes occur once per month;
milder episodes occur several times each week. The patient indicated that despite her age,
she was very active, enjoying tennis, skiing, and biking at her vacation home. The patient
further advised that she had a stressful occupation and a detail-oriented, compulsive
temperament. She suffered from occasional ‘‘stress’’ headaches and her medical history
was significant for hypertension, elevated cholesterol, and environmental allergies. During
the elicitation of the history, the patient provided Internet search results and a typed list of
questions.

Physical Examination

The neurologic examination was normal, except that the patient had increased sway on
Romberg’s test. Gait was normal. Otologic examination was normal except that audibility
of finger rub on the right was reduced. Pressure changes induced in the external auditory
canal by pneumatic otoscopy produced no dizziness or nystagmus. Neurotologic examina-
tion revealed no spontaneous nystagmus. The patient had a normal head thrust test, normal
Dix-Hallpike tests, and normal stability on foam with the eyes open and closed.

140
 CASE 12: MENIERE’S DISEASE 141

Laboratory Testing

Videonystagmography: Ocular motor function including saccades, pursuit, and optokinetic

nystagmus was normal. A low-amplitude left-beating spontaneous vestibular nystagmus
was noted. There was no positional nystagmus. Caloric irrigation revealed a mild (<50%)
right reduced vestibular response.
Rotational testing revealed normal gain and phase with a mild left directional preponderance.
Posturography was abnormal in a nonspecific pattern.
Audiometric testing showed normal hearing in the left ear and a moderate low-frequency
sensorineural hearing loss in the right ear. Word recognition scores were 88 percent on the right
and 100 percent on the left.
An MRI scan of the brain with and without gadolinium enhancement was normal.
VEMPs were normal in both ears.

Diagnosis/Differential Diagnosis

Question 1: What is this patient’s most likely diagnosis?

Answer 1: This patient is likely to have Meniere’s disease (see Cases 9, 20, 24, 29,
and 42) despite being aged 60.1 The symptoms of recurrent vertigo, hearing loss,
tinnitus, and aural fullness are characteristic of Meniere’s disease. However,
Meniere’s disease is a clinical diagnosis. No test is absolutely diagnostic for this
disease, and the presence of endolymphatic hydrops can be proved with certainty
only by postmortem histologic examination of the temporal bones. It is important
that the term Meniere’s disease not be used to describe all forms of dizziness but be
restricted to patients who manifest the full symptom complex described above.
However, some patients manifest only part of the syndrome with vertigo similar to
that seen with Meniere’s disease but without hearing loss, tinnitus, and aural fullness.
These patients can be described as possibly having Meniere’s disease. In these
individuals, the true diagnosis often becomes evident over time.
This patient was given the diagnosis of Meniere’s disease.

Treatment/Managment

Question 2: What are the options for treating this patient?

Answer 2: It is essential that treatable causes of endolymphatic hydrops, such as
immunologic, allergic, metabolic and endocrine disorders, infectious diseases, and
central nervous system abnormalities be considered and ruled out. A number of
factors such as stress, smoking, excessive salt intake, and the use of alcohol and
caffeine are known to be capable of exacerbating Meniere’s disease, and the patient
should be encouraged to adjust her lifestyle accordingly. The use of a diuretic and
dietary salt restriction is the most common initial treatment of Meniere’s disease.2
Other medications that have been used include vasodilators, vestibular suppressants,
and calcium channel blockers. It is estimated that about 20% of individuals with
Meniere’s disease will eventually fail medical therapy.3 Individuals such as this patient,
who have failed medical therapy, are faced with using symptomatic relief for each
episode or considering nonablative or ablative surgical intervention. Because the patient
is early in the course of her disease, that is, less than 1 year, has only mild hearing and
142 VESTIBULAR DISORDERS

vestibular loss, and has an active lifestyle, discussion should center on further medical
management and nonablative treatments.
The patient was continued on a low salt diet and diuretic. Sublingual lorazepam was
prescribed for symptomatic relief of vertigo and promethazine suppositories were
prescribed for nausea and vomiting associated with severe episodes of vertigo. A trial of
a verapamil and an allergy evaluation were ordered.
The patient returned in 2 months with a vertigo diary indicating no improvement in
the frequency or severity of vertigo. The patient wanted information regarding addi-
tional treatment options.
Question 3: What treatment options are available to manage vertigo caused by Meniere’s
disease that is refractory to medical therapy?
Answer 3: The treatment options for managing vertigo caused by medically refractory
Meniere’s disease include nonablative measures such as pulsed micro-pressure, trans-
tympanic steroids, and endolymphatic sac surgery, and ablative measures such as
chemical or surgical labyrinthectomy and vestibular nerve section. It is essential that
the patient understand that none of these procedures benefit the hearing loss, tinnitus,
or aural fullness associated with Meniere’s disease.
Question 4: What is pulsed micro-pressure treatment?
Answer 4: One common observation in patients with Meniere’s disease is how
changes in ambient atmospheric pressure can improve symptoms or worsen symp-
toms. This observation was tested by Densert in 1982 who documented consistent
improvement in Meniere’s symptoms following over-pressure treatments via a
hyperbaric chamber.4 The mechanism of this effect is unknown but may involve
changes in the labyrinthine vascular network5 or a reduction of endolymph fluid
volume by the intermittent pressure that produces a ‘‘pumping effect’’ at the level
of the endolymphatic valve of Bast.6 Based on these observations a portable low
pressure delivery device called the Meniett (Medtronic Xomed Inc, Jacksonville Fl,
USA) was developed and approved for sale as a class II medical device in 1999. The
Meniett delivers low amplitude (mean 12 cm water) 0.6 sec duration pressure
pulses at 6 Hz into the external auditory canal (Case 12: Figure 1). To use the
Meniett, a pressure equalization tube is first placed in the patient’s tympanic
membrane. An occlusive, soft-tipped probe is then held to the ear for the duration

Case 12: Figure 1 Meniett Device. An occlusive, soft tipped probe held to the external ear canal
delivers low pressure pulses. A pressure equalization tube is present in the tympanic membrane
to allow pressure pulses to reach the inner ear.
 CASE 12: MENIERE’S DISEASE 143

of the preprogrammed pressure cycles (about 5 minutes). The device is used three
to five times a day. Typically, patients are asked to use the device for 6 weeks and
then are reassessed for a favorable treatment response. If the intensity and fre-
quency of vertigo is decreasing, the treatment should be continued until vertigo
control is achieved. Some patients with good responses prefer to use the device
indefinitely while others prefer to discontinue use after a 6-month vertigo-free
interval.
Question 5: Is there evidence that using pulsed micropressure is an effective treatment for
Meniere’s disease?
Answer 5: Several controlled clinical trials have demonstrated greater relief of
vertigo with the Meniett than in controls.7,8,9,10 Both positive short-term and
long-term effects have been observed with Meniett use. Patients with greater
vestibular weakness on caloric tests and greater baseline vertigo severity tended
to respond more to the Meniett. Alternatively, hearing improvement has not been
consistently demonstrated with Meniett use. These results suggest the Meniett
device is a reasonable nonablative therapeutic alternative.
Question 6: What is intratympanic steroid perfusion?
Answer 6: The beneficial effects of systemic corticosteroids for treatment of
immune-related inner ear disorders has spurred interest in determining whether
corticosteroids may also be beneficial in controlling inner ear dysfunction asso-
ciated with Meniere’s disease. In order to reduce the side effects of systemic
corticosteroid use, more targeted application of steroids to the inner ear via intra-
tympanic steroid perfusion has been gaining popularity. Intratympanic steroid
perfusion consists of an injection of a corticosteroid agent into the middle ear space.
Once in the middle ear, the steroid diffuses through the round window membrane
into the inner ear. Intratympanic administration results in increased drug delivery
into the inner ear relative to systemic injection.11 Studies of the pharmacokinetics of
single intratympanic injections of dexamethasone indicate the drug enters the
inner ear within minutes, reaches maximal concentration within 1 hour, and is
absent within 24 hours. Distribution of the drug generally parallels locations of
inner ear glucocorticoid receptors.12
Question 7: What effect do corticosteroids have on the inner ear?
Answer 7: The cochlear mechanisms involved in steroid-responsive hearing loss are
not fully understood. Glucocorticoids may influence hearing recovery through
glucocorticoid receptor-mediated anti-inflammatory and immunosuppressive
functions, and via mineralocorticoid receptor regulation of sodium, potassium,
and other electrolyte homeostasis.13
Question 8: Is there evidence that steroid perfusions are an effective treatment for
Meniere’s disease?
Answer 8: The evidence for a beneficial effect of intratympanic steroid use for
Meniere’s disease is scant and decidedly mixed. Most publications on the use of
intratympanic steroids in Meniere’s disease are uncontrolled case series reports
lacking comparison to untreated patients. Moreover, there is wide variability in
the severity of disease and treatment protocols. There are only two small prospec-
tive, controlled, randomized trials published. In a study by Silverstein,14 no bene-
ficial effect on hearing loss, tinnitus, or aural fullness was seen in a group of patients
with advanced Meneire’s disease. In a study by Garduno-Anaya,15 vertigo control 2
144 VESTIBULAR DISORDERS

years later was significantly better after dexamethasone injections than after pla-
cebo injections. No differences in hearing were found between active and control
groups of patients. Despite inconclusive evidence of efficacy, intratympanic steroid
perfusion may be considered since minimal side effects have been reported and
steroid treatment may reduce the likelihood of further ablative therapy.16
Question 9: What is endolymphatic sac surgery and how does it relieve symptoms of
Meniere’s disease?
Answer 9: Endolymphatic sac surgery presumably reduces vertigo by affecting the
underlying pathologic process of endolymphatic hydrops, that is, by reducing
endolymphatic pressure.17 The endolymphatic sac is illustrated in Case 12: Figure
2. Endolymphatic sac surgery is a safe and uncomplicated procedure. It is usually
performed as outpatient surgery and requires only 3 to 5 days of post-surgical con-
valescence. The success rate for complete control of vertigo following endolymphatic
sac surgery ranges between 50 to 70%.18,19 Many surgeons recognize that this low
success rate approximates what would be expected from a placebo procedure, and thus
do not routinely recommend sac surgery.20 Interestingly, despite the modest rate of

Case 12: Figure 2 Three-dimensional computer-aided reconstruction of the vestibular aqueduct

and endolymphatic sac anatomically positioned within a microdissected left human temporal
bone. VA = vestibular aqueduct; EAVA = external aperture of the vestibular aqueduct; FC =
facial canal; EACA = external aperture of the cochlear aqueduct; IACA = internal aperture of
the cochlear aqueduct; IAP = internal auditory canal; JF = jugular foramen; PSCC = posterior
semicircular canal; SS = sigmoid sinus; SSCC = superior semicircular canal.
With permission from Wackym, PA, et al: Re-evaluation of the role of the human endolymphatic sac in
Meniere’s disease. Otolaryngol Head Neck Surg 102:732–744, 1990. 21
 CASE 12: MENIERE’S DISEASE 145

complete vertigo control following endolymphatic sac surgery, patients often choose to
undergo sac surgery because of the prospect of improving their vertigo without under-
going a more involved surgical procedure.
The patient valued preserving her residual vestibular function and hearing and
elected to undergo a series of four once-a-week intratympanic injections of decadron.

Follow-Up

Six weeks following treatment, hearing was unchanged. Several mild episodes of vertigo
occurred with no major spells. The patient was also counseled to implement lifestyle
changes to reduce stress and to implement dietary changes to better control her hypertension
and elevated cholesterol.

Summary

A 60-year-old real estate professional presented with persistent episodic vertigo despite
standard medical management of Meneire’s disease. She had an active lifestyle, with mild
hearing loss and normal balance in between episodes of acute vertigo, and she wanted
additional treatment that preserved her hearing and vestibular function. She considered
several nonvestibular ablative treatments, deciding on intratympanic steroid injections.
Short-term follow-up has been favorable. She is also implementing dietary and lifestyle
changes.

Teaching Points

1. Meniere’s disease is a clinical diagnosis based on characteristic symptoms of

recurrent vertigo, hearing loss, tinnitus, and aural fullness. It is important that the
term Meniere’s disease not be used to describe all forms of dizziness.
2. About 20% of patients with Meniere’s disease will continue to experience episodic
vertigo despite nonsurgical interventions. In these patients, additional treatment
options can be divided into those that preserve vestibular function and those that
ablate vestibular function. Nonablative measures include pulsed micro-pressure
therapy, transtympanic steroids, and endolymphatic sac surgery. Ablative measures
include chemical or surgical labyrinthectomy and vestibular nerve section.
3. Patients frequently prefer nonablative interventions early in the course of
Meniere’s disease when only mild hearing loss is present and baseline vestibular
function is normal or only mildly reduced.

References
1. Shojaku H, Watanabe Y, Fujisaka M, Tsubota M, Kobayashi K, Yasumura S, Mizukoshi K:
Epidemiologic characteristics of definite Ménière’s disease in Japan. A long-term survey of
Toyama and Niigata prefectures. ORL J Otorhinolaryngol Relat Spec 67(5):305–309, 2005.
Epub 2005 Dec. 15.
2. Coelho DH, Lalwani AK: Medical management of Ménière’s disease. Laryngoscope
118(6):1099–1108, 2008.
3. Sajjadi H, Paparella MM: Meniere’s disease. Lancet 372(9636):406-414, 2008.
146 VESTIBULAR DISORDERS

4. Densert B, Densert O: Overpressure treatment of Meneire’s disease. Laryngoscope

92:1285–1292, 1982.
5. Densert B, Denset O, Erlandsson B, Shepard H: Transmission of complex pressure waves
through the perilymph in cats. Acta Otolaryngol 102:403–409, 1986.
6. Salt AN, Rask-Andersen H: Responses of the endolymphatic sac to perilymphatic pressure
manipulations suggest the presence of a one-way valve. Abstract ARO, 2004.
7. Odkvist LM, Arlinger S, Billermark E, Densert B, Lindholm S, Wallqvist J: Effects of middle
ear pressure changes on clinical symptoms in patients with Meniere’s disease—a clinical
multicenter placebo-controlled study. Acta Otolaryngol Suppl 543:99–101, 2000.
8. Gates GA, Green JD, Tucci DL, Telian SL: The effects of transtympanic micropressure
traetment in people with unilatral Meniere’s disease. Arch Oto Head Neck Surg 130:718–725,
2004.
9. Gates GA, Verrall A, Green JD, Tucci DL, Telian SA: Meniett clinical trial: Long-term
follow-up. Ach Otolaryngol Head Neck Surg 132:1311–1316, 2006.
10. Dornhoffer JL, King D: The effect of the Meniett device in patients with Meniere’s disease:
Long-term results. Otol Neurotol 29:868–874, 2008.
11. Parnes LS, Sun AH, Freeman DJ: Corticosteroid pharmacokinetics in the inner ear fluids: An
animal study followed by clinical application. Laryngoscope 109(7 Pt 2):1–17, 1999.
12. Hargunani CA, Kempton JB, DeGagne JM, Trune DR: Intratympanic injection of dexa-
methasone: Time course of inner ear distribution and conversion to its active form. Otol
Neurotol 27(4):564–569, 2006.
13. Trune DR, Kempton JB, Gross ND: Mineralocorticoid receptor mediates glucocorticoid
treatment effects in the autoimmune mouse ear. Hear Res 212(1–2):22–32, 2006.
14. Silverstein H, Isaacson JE, Olds MJ, Rowan PT, Rosenberg S: Dexamethasone inner ear
perfusion for the treatment of Meniere’s disease: A prospective, randomized, double-blind,
crossover trial. Am J Otol 19(2):196–201, 1998.
15. Garduño-Anaya MA, Couthino DeToledo H, Hinojosa- González R, Pane-Pianese C, Rı́os-
Castañeda LC. Dexamethasone inner ear perfusion by intratympanic injection in unilateral
Ménière’s disease: A two-year prospective, placebo-controlled, double-blind, randomized
trial. Otolaryngol Head Neck Surg 133(2):285–294, 2005.
16. Boleas-Aguirre MS, Lin FR, Della Santina CC, Minor LB, Carey JP: Longitudinal results with
intratympanic dexamethasone in the treatment of Ménière’s disease. Otol Neurotol 29(1):33–
38, 2008.
17. Monsell EM, Wiet RJ: Endolymphatic sac surgery: Methods of study and results. Am J
Otology 9:396–402, 1988.
18. Convert C, Franco-Vidal V, Bebear JP, Darrouzet V: Outcome-based assessment of endo-
lymphatic sac decompression for Ménière’s disease using the Ménière’s disease outcome
questionnaire: A review of 90 patients. Otol Neurotol 27(5):687–696, 2006.
19. Ostrowski VB, Kartush JM: Endolymphatic sac-vein decompression for intractable Meniere’s
disease: Long term treatment results. Otolaryngol Head Neck Surg. 128(4):550–559, 2003.
20. Silversein H, Smouha E, Jones R: Natural history vs. surgery for Meniere’s disease.
Otolaryngol Head Neck Surg. 100:6–16, 1989.
21. Wackym, PA, et al: Re-evaluation of the role of the human endolymphatic sac in Meniere’s
disease. Otolaryngol Head Neck Surg 102:732–744, 1990.
Case 13
Labyrinthine Concussion

History

A 44-year-old woman who worked as a travel agent complained of dizziness and disequi-
librium that were present constantly but fluctuated in severity from day to day. The patient
dated the onset of her symptoms to head trauma sustained during a motor vehicle accident
10 months before evaluation. She was a restrained driver of a car that was struck on the
passenger side, causing her to first move to the right and then back toward the left, striking
the left side of her head on the driver’s side of the passenger compartment. The patient had
no loss of consciousness at the time of the accident. She was particularly symptomatic
during rapid head movement and had difficulty ambulating in dimly lit environments.
Headaches, which were a new complaint following the motor vehicle accident, occurred
irregularly. The patient noted that hearing in the right ear was not as good as in the left
when using her cell phone. Symptoms were not exacerbated by Valsalva maneuvers such
as coughing, sneezing, or straining during bowel movements. There was no positional
dizziness. There was no anxiety, insomnia, undue fatigue, or personality change. There was
no significant medical history. The family history was noncontributory.
A CT scan of the head obtained by the patient’s primary care physician several
weeks following the motor vehicle accident was within the normal limits. The patient
had used meclizine, obtaining some relief, but she continued to experience dizziness
and disequilibrium.
Question 1: Based on the patient’s history, what is the likely diagnosis?
Answer 1: This patient is likely to have suffered from a labyrinthine concussion
caused by head trauma during the motor vehicle accident.1,2 Other considera-
tions include perilymphatic fistula (see Case 60), brainstem concussion, and
cervicogenic vertigo (see Case 58). A further consideration is post-traumatic
endolymphatic hydrops. Other possibilities include conditions that may be unrelated
to the motor vehicle accident or exacerbated by it, such as a prior compensated
peripheral vestibulopathy or a central nervous system disorder such as demyeli-
nating disease or a mass lesion. The latter two conditions are unlikely, but for
uncertain reasons they can sometimes come to light following head trauma and
so must be considered.

147
148 VESTIBULAR DISORDERS

Physical Examination

The general and neurologic examinations were normal. Otologic examination revealed
normal-appearing tympanic membranes with normal mobility on pneumatic otoscopy.
During tuning forks examination using 512 and 1024 Hz forks, Weber’s test lateralized
to the left and the Rinne tests were positive bilaterally, indicating a possible sensorineural
type of hearing loss on the right. Neuro-otologic examination revealed low amplitude
spontaneous left-beating nystagmus on leftward gaze with infrared goggles, normal head
thrust testing, negative Dix-Hallpike maneuvers, no cervical nystagmus, difficulty standing
on a compliant foam surface with the eyes closed, and no nystagmus observed with
infrared glasses during hyperventilation, tragal stimulation, Valsalva maneuvers, or
pneumatic otoscopy. Gait was mildly unsteady.

Laboratory Testing

Videonystagmography: Ocular motor function was normal. A spontaneous left-beating

vestibular nystagmus of 2–3 degrees per second was present. There was no positional
nystagmus. Caloric irrigations revealed a right-reduced vestibular response of 35%.
Rotational testing revealed a mild left-directional preponderance.
Posturography indicated excessive sway on Conditions 5 and 6.
VEMPs were reduced on the right.
Audiometric testing revealed a mild to moderate right-sided sensorineural hearing loss
that was greatest in the higher frequencies (Case 13: Figure 1). Hearing in the left ear was
normal. Results of electrocochleography, which was performed to evaluate the possibility

Case 13: Figure 1 Audiogram demonstrating a right-sided sensorineural hearing loss.

 CASE 13: LABYRINTHINE CONCUSSION 149

of posttraumatic endolymphatic hydrops (see Cases 9, 12, 20, 24, 42) or perilymphatic
fistula (see Case 60), was normal.
A CT scan of the brain was normal.
Question 2: Based on the patient’s history, physical examination, and laboratory studies,
what is the most likely diagnosis?
Answer 2: The most likely diagnosis is labyrinthine concussion on the right as a result
of head trauma suffered during a motor vehicle accident. This diagnosis is sup-
ported by the combination of the asymmetric sensorineural hearing loss in the right
ear and a right unilateral reduced vestibular response on caloric testing and VEMP
testing. The fact that the patient described hitting the left side of her head against
the passenger compartment seems inconsistent with the right-sided audiovestibular
loss. However, because the exact mechanism of injury in labyrinthine concussion
is not well known, the fact that head trauma occurred is more important than the
side of the head impact. Further, the concept of coup-contracoup injuries provides
a possible explanation for the laterality of the patient’s findings, that is, she struck
the left side of her head but had a right labyrinthine injury. There is also a
possibility that a combination of central and peripheral dysfunction is causing
the present symptoms (see Case 2).

Question 3: What is the pathophysiologic basis for labyrinthine concussion?

Answer 3: The mechanism of injury in labyrinthine concussion is poorly under-
stood.3,4 Possible mechanisms of concussive injury to the labyrinth include pressure
shock waves transmitted directly to the labyrinth by the skull, implosive barotrauma
in the form of acoustic energy, and barometric pressure waves transmitted via the
tympanic membrane and the ossicular chain to the labyrinth. Explosive pressure
changes can also occur from sudden shifts of the brain or intracranial fluids. Sudden
intracranial pressure changes can be transmitted to the labyrinth via the cochlear
aqueduct, endolymphatic sac, or cribriform regions of the internal auditory canal
that transmit eighth cranial nerve fibers into the labyrinth. Sudden pressure shifts of
the labyrinthine fluids can cause hemorrhage or tears of fine labyrinthine mem-
branes, allowing intermixing of perilymph and endolymph and local metabolic
disturbances that could result in the formation of endolymphatic hydrops. Sudden
pressure shifts can also damage hair cell stereocilia, the organ of Corti, or the various
specialized cupular structures, cause collapse or fibrosis of the endolymphatic
membranes, or cause the loss of hair cells themselves.

Question 4: Why is this patient still symptomatic 10 months following the trauma?
Answer 4: The patient has not compensated for her peripheral vestibular loss. As
discussed in Case 3, impaired compensation for a peripheral vestibular lesion may
be a result of one or more of several causes. This patient may be experiencing
erroneous or fluctuating peripheral vestibular input as a result of labyrinthine trauma.
It is possible that the central vestibular system has more difficulty compensating
for erroneous or fluctuating vestibular signals from the peripheral end organ than
for a complete or fixed peripheral vestibular deficit. Following any significant head
injury, subtle central nervous system dysfunction that could impair central com-
pensatory processes is also possible. No abnormalities of vision or proprioception
are noted, and thus these causes are unlikely to be contributing to the current
balance dysfunction. Inadequate sensory input as a result of sedentary behavior
also is possible and could have impaired compensation.
150 VESTIBULAR DISORDERS

Question 5: What conditions other than impaired compensation for a peripheral vestibular
lesion may underlie persistent dizziness following head trauma?
Answer 5: Conditions other than impaired compensation for a peripheral vestibular
lesion that may underlie persistent dizziness following head trauma include benign
paroxysmal positional vertigo (see Cases 7, 23, 24, 25, 26, 28, 39), perilymphatic
fistula (discussed in Case 60), posttraumatic endolymphatic hydrops, and brainstem
or cerebral concussion. This patient is unlikely to be suffering from benign parox-
ysmal positional vertigo, considering the absence of a history of positional vertigo
and negative Dix-Hallpike maneuvers. Perilymphatic fistula is more difficult to rule
out, but the patient does not report fluctuation of hearing loss, nor are her
symptoms exacerbated by coughing, sneezing, or straining during bowel move-
ments, and no symptoms or signs were induced by tragal stimulation, Valsalva
maneuvers, or pneumatic otoscopy. Electrocochleography may be positive in
either endolymphatic hydrops or perilymphatic fistula but was negative in this
patient. Nevertheless, perilymphatic fistula should remain a possibility because of
the inherent difficulty in diagnosing perilymphatic fistula (see Case 60). Post-
traumatic endolymphatic hydrops is unlikely because of the absence of tinnitus,
ear fullness, or low frequency hearing loss. The patient is unlikely to have suffered
from a brainstem contusion because neurologic signs are absent. However, it is
possible that some degree of the patient’s impaired compensation may relate to a
mild brainstem concussion. The patient is unlikely to have suffered from a sig-
nificant cerebral concussion since there are no complaints of abnormal memory or
personality change. Her headaches, however, suggest the possibility of a mild
cerebral concussion, although the headaches could be the result of head trauma
without cerebral concussion.

Diagnosis/Differential Diagnosis

The patient was given a diagnosis of labyrinthine concussion.

Treatment/Management

Because the patient was symptomatic primarily during rapid head movement and while
ambulating in dimly lit environments, she was treated with vestibular rehabilitation
therapy. She was also given a vestibular suppressant, meclizine 25 mg, to be used on an
as-needed basis up to 3 times per day, only when she was particularly symptomatic. The
patient was also advised that recovery might be prolonged because of the possibility of a
brainstem concussion and that improvement could continue for up to 2 years. The plan was
to discontinue meclizine as soon as possible following the hoped-for successful treatment
with vestibular rehabilitation therapy.

Follow-Up

The patient’s symptoms gradually decreased and her balance improved noticeably following
vestibular rehabilitation therapy. At the 6-month follow-up visit, she was using meclizine
only a few days each month when her symptoms seemed worse.
 CASE 13: LABYRINTHINE CONCUSSION 151

Summary

A 44-year-old woman complained of 10 months of dizziness that began following a motor

vehicle accident in which she struck the side of her head against the inside of the passenger
compartment without loss of consciousness. The patient’s laboratory test results suggested
a mild unilateral reduced vestibular response and a high-frequency sensorineural hearing
loss on the same side. These findings suggested a labyrinthine concussion. The patient’s
persistent symptoms, which suggested impaired compensation, may have been based on
abnormal or fluctuating peripheral vestibular function or sedentary behavior, and may have
been compounded by a mild brainstem concussion. Treatment consisted of vestibular
rehabilitation therapy and a vestibular-suppressant agent to be used for a short time only
on an as-needed basis.

Teaching Points

1. The differential diagnosis for post-traumatic dizziness includes post-traumatic

benign paroxysmal positional vertigo, post-traumatic endolymphatic hydrops,
labyrinthine concussion, perilymphatic fistula, brainstem concussion, and
cervical-related vertigo. Other possibilities include conditions that may be
unmasked by the trauma, such as a prior compensated peripheral vestibulopathy or a
central nervous system disorder such as demyelinating disease or a mass lesion.
2. A diagnosis of labyrinthine concussion is suggested by the presence of symptoms or
signs of inner ear dysfunction such as asymmetric sensorineural hearing loss, and a
unilateral reduced vestibular response on caloric testing following head trauma.
3. Prolonged dizziness following head trauma may relate to impaired compensation
for a trauma-related peripheral vestibular lesion. Impaired compensation may be
based on aberrant or fluctuating peripheral vestibular input as a result of labyrinthine
trauma, subtle central nervous system dysfunction, inadequate sensory input as a result
of sedentary behavior, or subclinical damage to the contralateral ear. Following head
trauma, other conditions such as benign paroxysmal positional vertigo, perilymphatic
fistula, and brainstem or cerebral concussion also may underlie persistent dizziness.
4. The pathophysiology of labyrinthine concussion is poorly understood. Possible
mechanisms of injury include (1) implosive barotrauma in the form of acoustic
energy or barometric pressure waves transmitted via the skull, the tympanic
membrane, or the ossicular chain to the labyrinth; (2) explosive pressure changes
from sudden shifts of the brain or intracranial fluids; or (3) sudden pressure shifts of
labyrinthine fluids that can cause hemorrhage or tears of fine labyrinthine
membranes, allowing intermixing of perilymph and endolymph and local
metabolic disturbances.

References

1. Fitzgerald DC: Head trauma: hearing loss and dizziness. J Trauma 40(3):488–496, 1996.
2. Ernst A, Basta D, Seidl RO, Todt I, Scherer H, Clarke A: Management of posttraumatic
vertigo. Otolaryngol Head Neck Surg, 132(4):554–558, 2005.
3. Schuknecht HF, Neff WD, Perlman HD: An experimental study of auditory damage following
blows to the head. Ann Otol Rhinol Laryngol 60:273–289, 1951.
4. Schuknecht HF: A clinical study of auditory damage following blows to the head. Ann Otol
Rhinol Laryngol 59:331–359, 1950.
Case 14
Mild Traumatic Brain Injury

History

A 15-year-old female high school student was seen for a complaint of dizziness 1 month
following a mild traumatic brain injury suffered while playing soccer. The patient was
referred for evaluation by her neuropsychologist and physiatrist and was accompanied by
her mother. The injury occurred while the patient was heading a ball and collided with an
opposing team member. There was no apparent loss of consciousness although the patient
cannot recall the injury. She clearly remembers being in the locker room after being
removed from the game. The patient characterized her dizziness as a sense of lightheadedness
and a swimming sensation. There was no vertigo. Symptoms were present at rest but were
exacerbated by physical and cognitive activity and by exposure to loud sounds and bright
light. There was a complaint of headache, which often but not consistently accompanied
dizziness. Headache, like dizziness, was associated with photophobia and phonophobia.
Question 1: Based upon the patient’s history, what is the most likely diagnosis and what
additional history, if any, would be helpful?
Answer 1: This patient’s history suggests a mild traumatic brain injury. Mild traumatic
brain injury is often associated with dizziness.1,2 Moreover, the patient’s headaches
are suggestive of post-traumatic migraine and appear to be associated with the
patient’s dizziness suggesting a condition similar to migraine-related dizziness.3 An
additional diagnostic consideration is a labyrinthine concussion (see Case 13) in
combination with mild traumatic brain injury. Additional history regarding school
performance, social activities, and sleep would be helpful as would information
about medication use, if any.

Additional History

Additional history revealed that the patient’s sleep was disturbed and that she was
generally sleepy throughout the day. The patient had been away from high school for 1
month and had returned to a partial schedule 2 weeks prior to evaluation. School perfor-
mance was still poor, which was blamed in part on difficulty reading for more than several
minutes at a time. In addition to complaints of dizziness and headache, the patient
complained of being forgetful and having difficulty functioning at social gatherings.
Shopping malls were especially challenging as were any open spaces or spaces with

152
 CASE 14: MILD TRAUMATIC BRAIN INJURY 153

excessive visual motion. Current medications included amantadine during the day and
trazadone taken at bedtime.
Question 2: In what way does the additional historical information influence the diagnostic
considerations?
Answer 2: The patient’s difficulty with cognition, social activities, and sleep coupled
with headache and dizziness suggest a post-concussion syndrome. The visual
complaints suggest space and motion discomfort, which may signal a vestibular
system abnormality.

Physical Examination

The patient’s general examination, otologic examination, and neurologic examination

were normal aside from difficulty converging her eyes on a near target and mildly unsteady
gait. There was no nystagmus observed during the physical examination. Head thrust
testing was normal in both directions. There was no ocular misalignment noted including
a normal examination with a Maddox rod. The patient had difficulty standing on a
compliant foam pad with eyes closed.

Laboratory Testing

Videonystagmography: Ocular motor testing revealed symmetrically impaired ocular

pursuit and optokinetic nystagmus. No spontaneous vestibular nystagmus was seen.
There was no positional nystagmus. Caloric irrigations indicated normal responses.
Rotational testing revealed a directional preponderance.
Vestibular evoked myogenic potentials were normal.
Computerized platform posturography indicated excessive sway in a nonspecific pattern.
Audiometric testing was normal.
Magnetic resonance imaging of the brain was normal.
Question 3: Based on the patient’s laboratory tests, what is this patient’s most likely
diagnosis?
Answer 3: Laboratory testing suggests that the patient has not suffered from a
peripheral vestibular ailment. However, the patient does have evidence for an
ongoing vestibular ocular reflex asymmetry based upon her directional preponderance
on rotational testing. Additionally, postural sway was excessive, a nonspecific
abnormality that could be related to either central or peripheral vestibular
structures.4,5 Magnetic resonance imaging is usually normal in patients with mild
traumatic brain injury, as in this case. Although MRI findings are generally normal in
mild traumatic brain injury, there is emerging evidence that there are demonstrable
brain changes such as abnormalities in brain metabolism.6

Diagnosis/Differential Diagnosis

This patient was given the diagnosis of mild traumatic brain injury.
154 VESTIBULAR DISORDERS

Treatment

Question 4: What are the treatment options for this patient?

Answer 4: This patient should be treated for her headache and dizziness related to
headache. Consideration should be given to treatment with a low dose of a tricyclic
antidepressant such as imipramine 10 mg p.o. nightly. Additionally, the patient
should be referred for a course of balance rehabilitation therapy to include ocular
convergence and balance exercises. The patient should be reminded that excessive
stimulation should be avoided with limitation of strenuous physical activity. The
patient should be encouraged to follow up with her physiatrist.

Follow-Up

The patient remained out of school for 2 months at the suggestion of her neuropsychologist.
Symptoms gradually improved and the patient was able to return to her usual activities over
a period of several months. Convergence eye movements were improved. The patient
discontinued contact sports. There is evidence that young females do not recover as well as
males from mild traumatic brain injury.7

Summary

A 15-year-old female presented with dizziness 1 month following a mild traumatic brain
injury without loss of consciousness that occurred while playing soccer. There was a
complaint of headache, which often, but not consistently, accompanied dizziness. There
was no vertigo. Symptoms were exacerbated by physical and cognitive activity and by
exposure to loud sounds and bright light. There was a sleep disturbance and recent school
performance was poor. Physical examination was normal except for difficulty converging
on a near target and standing on a compliant foam pad with eyes closed. Rotational testing
and posturography were abnormal. This patient was given the diagnosis of mild traumatic
brain injury. Treatment consisted of amantadine and balance rehabilitation that included
ocular convergence exercises. After 2 months, symptoms gradually improved and the
patient returned to school but discontinued contact sports.

Teaching Points

1. Headache and poor sleep can interfere with recovery from mild traumatic brain
injury.
2. Excessive stimulation should be avoided in persons recovering from mild
traumatic brain injury.
3. Treatment of patients with dizziness secondary to mild traumatic brain injury
requires a team approach including a neuropsychologist and a physiatrist in addition
to a physical therapist with expertise in balance disorders and a physician with expertise
in vestibular disorders.
4. Young females do not recover as quickly from mild traumatic brain injury as
males.
 CASE 14: MILD TRAUMATIC BRAIN INJURY 155

5. Although MRI findings are generally normal in mild traumatic brain injury, there
is emerging evidence that there are demonstrable brain changes such as
abnormalities in brain metabolism.

References

1. Davies RA, Luxon LM: Dizziness following head injury: A neuro-otological study. J Neurol
242:222–230, 1995.
2. Hoffer ME, Aalough BJ, Gottshall KR: Posttraumatic balance disorders. Int Tinnitus J
13(1):69–72, 2007.
3. Mihalik JP, Stump JE, Collins MW, Lovell MR, Field M, Maroon JC: Posttraumatic migraine
characteristics in athletes following sports-related concussion. J Neruosurg 102:850–855,
2005.
4. Broglio SP, Ferrara MS, Sopiarz K, Kelly MS: Reliable change of the sensory organization
test. Clin J Sport Med 18:148–154, 2008.
5. Guskiewicz KM, Ross SE, Marshall SW: Postural stability and neuropsychological deficits
after concussion in collegiate athletes. J Athl Train 36(3):263–273, 2001.
6. Giza CC, Hovda DA: The neurometabolic cascade of concussion. J Athl Train 36(3):228–235,
2001.
7. Morrison WE, Arbelaez JJ, Facler JC, DeMaio A, Paidas CN: Gender and age effects on
outcome after pediatric traumatic brain injury. Pediatr Crit Care Med 5(2):145–151, 2004.
Case 15
Decompensated Unilateral
Peripheral Vestibular Loss

History

A 60-year-old woman who worked as a billing clerk presented with nonspecific dizziness
and gait instability 3 weeks following discharge from the hospital following a 1-week stay
for pneumonia. During the patient’s recent hospitalization she was treated with
cephalosporins. She did not receive aminoglycosides. The patient’s medical history was
significant for chronic obstructive pulmonary disease and a remote history of ‘‘vertigo.’’ At
the time of the prior vertigo, 20 years earlier, the patient was given a diagnosis of Meniere’s
disease by the patient’s primary care physician, who prescribed meclizine. The illness 20
years earlier lasted for 1 week without associated hearing loss with complete resolution of
symptoms.
Question 1: Based on the history provided, what are the diagnostic considerations and
what further historical information would be helpful in reaching a diagnosis?
Answer 1: The patient’s history is consistent with vestibular neuritis in the remote past.
Despite a diagnosis of Meniere’s disease, the patient’s history is not suggestive of this
diagnosis because of the absence of hearing loss and the absence of repeated vertigi-
nous spells. Despite the absence of positional vertigo, this patient’s recent symptoms
may be on the basis of benign paroxysmal positional nystagmus and vertigo because
this condition can be seen following hospitalization. Other diagnostic considerations
include recurrent vestibular neuritis though the patient did not have a recent acute
vestibular syndrome. Otherwise, the patient’s differential diagnosis is quite broad.

Physical Examination

The patient had a normal general examination. Neurologic examination revealed a low-
amplitude right-beating nystagmus on rightward gaze using infrared video goggles. The
patient could not tandem walk. The patient was unable to stand on a compliant foam pad
with eyes closed without losing her balance. Gait was unsteady. Head thrust testing was
abnormal during rotations to the left but normal with rotations to the right. Dix-Hallpike
maneuvers were negative bilaterally. Sensation to light touch, pinprick, vibration, and
position was normal.

156
 CASE 15: DECOMPENSATED UNILATERAL PERIPHERAL VESTIBULAR LOSS 157

Question 2: Based on this additional information from the physical examination, what are
the diagnostic considerations?
Answer 2: The patient appears to have a vestibular loss on the left with an ongoing
vestibulo-ocular reflex and vestibulospinal abnormality. Lateralization, however, is
uncertain. The patient does not appear to be suffering from benign paroxysmal
positional vertigo. Further, the patient’s normal neurologic examination, aside from
abnormalities referable to vestibular dysfunction, reduce the likelihood of other
neurological abnormalities such as stroke and neurodegenerative disorders.

Laboratory Testing

Videonystagmography revealed a low amplitude right-beating spontaneous vestibular

nystagmus and a low amplitude direction fixed right-beating persistent positional nystagmus.
Caloric responses were absent on the left including absent responses to ice water irrigation
and normal on the right. There was a right directional preponderance on rotational testing,
with slightly decreased magnitude of responses and an increase in VOR phase lead.
Platform posturography testing was abnormal indicating a vestibular pattern.
Vestibular evoked myogenic potentials were absent on the left.
Question 3: Based on the information from history, physical examination, and laboratory
testing, what is the patient’s most likely diagnosis?
Answer 3: A left-sided peripheral vestibular loss was documented on laboratory
testing as was an ongoing VOR asymmetry and a vestibulospinal abnormality.
The most likely etiologies include a recurrence of vestibular neuritis or decompen-
sation from a previously compensated peripheral vestibular loss. The absence of
typical signs and symptoms consistent with a recent episode of acute vestibular loss
(See Cases 1 and 3) render a diagnosis of vestibular neuritis less likely.

Diagnosis/Differential Diagnosis

The patient was diagnosed as having a decompensation from a previously compensated

unilateral peripheral vestibular loss.
Question 4: What is the pathophysiology of vestibular decompensation?
Answer 4: The pathophysiology of vestibular decompensation is uncertain. One study
suggests that vestibular compensation is not permanent and can be disrupted by
neck afferents.1 Also, trigeminal stimulation in animals that have compensated from a
unilateral peripheral loss can lead to a remanifestation of vestibular nystagmus.2
Moreover, patients with compensated peripheral vestibular ailments have more
difficulty with cognitive functioning during vestibular stimulation than do normal
persons.3,4

Treatment

Question 5: What treatments can be suggested for a patient who has decompensated from a
previously compensated peripheral vestibular ailment?
158 VESTIBULAR DISORDERS

Answer 5: In general, impediments to the decompensation process should be

minimized, especially vestibular suppressant medications and a sedentary lifestyle.
Additionally, activities that are thought to promote compensation should be under-
taken. In this patient, meclizine should be discontinued and a course of balance
rehabilitation therapy should be initiated.
The patient was treated with a combination of discontinuation of meclizine and
referral for balance rehabilitation therapy.

Follow-Up

The patient was compliant with treatment recommendations and recovered to her baseline
status over the course of approximately 2 months. The patient continued to perform a home
exercise program prescribed by the physical therapist.

Summary

A 60-year-old woman presented with nonspecific dizziness and gait instability shortly after
recovering from pneumonia. The patient had suffered from an apparent vestibular neuritis
20 years earlier. Physical examination and laboratory testing suggested an active vestibular
disorder with a left peripheral loss, a low-amplitude spontaneous nystagmus and a directional
preponderance on rotational testing. The patient was diagnosed as having a decompensation
from a previously compensated unilateral peripheral vestibular loss. The patient was treated
with a combination of discontinuation of meclizine and referral for balance rehabilitation
therapy. The patient recovered to her baseline status over the course of approximately
2 months and continued to perform a home balance exercise program.

Teaching Points

1. Patients with previously compensated unilateral peripheral vestibular loss may

decompensate secondary to an illness unrelated to vestibular dysfunction.
2. The pathophysiology of decompensation is uncertain but may be related to disruption
of ongoing adaptations to a unilateral peripheral vestibular loss.
3. The treatment of vestibular decompensation is elimination of vestibular
suppressant medications and balance rehabilitation therapy.

References
1. Yagi T, Hatano G, MorizonoT: Role of dorsal neck proprioceptive inputs to vestibular
compensation in humans. Nippon Ika Daigaku Zasshi, 65(4):291–297, 1998.
2. Petrosini L, Troiani D. Vestibular compensation after hemilabyrinthectomy: Effects of
trigeminal neurotomy. Physiol Behav 22:133–137, 1979.
3. Redfern MS, Talkowski ME, Jennings JR, Furman JM: Cognitive influences in postural
control of patients with unilateral vestibular loss. Gait Posture 19:105–114, 2004.
4. Talkowski ME, Redfern MS, Jennings JR, Furman JM: Cognitive requirements for vestibular
and ocular motor processing in healthy adults and patients with unilateral vestibular lesions.
J Cogn Neurosci 17(9):1–10, 2005.
Case 16
Nonspecific Vestibulopathy

History

A 30-year-old female data processor presented with a chief complaint of dizziness and
disequilibrium. The patient’s complaints were of approximately 1 year’s duration, worse in
the last several months, especially premenstrually. There was a constant sense of dizziness
and disequilibrium, with periodic exacerbations lasting for several days. There was no
positional dizziness. When the patient was symptomatic, she noticed that rapid head
movements were bothersome and that looking at her computer screen at work caused
discomfort, including mild nausea and ‘‘eye strain.’’ She had no neurologic complaints.
The patient walked regularly for exercise and noticed that, when symptomatic, she veered
slightly both to the right and to the left. There was no history of headache and no family
history of migraine headache. The patient had no complaint of hearing loss or tinnitus and
no complaint of fullness, pain, or stuffiness in the ears. She was evaluated extensively by
her primary care physician, with no diagnosis reached. An MRI scan revealed that the
cerebellar tonsils were 2 mm below the foramen magnum, without evidence of compression
of brainstem or caudal midline cerebellar structures. The patient noted some increase in
symptoms in shopping malls and grocery stores but was able to carry on her homemaking
activities. She had not experienced panic attacks. The patient used meclizine on an as-
needed basis. This provided some relief, but she was still symptomatic.
Question 1: Based on the patient’s history, what is the differential diagnosis?
Answer 1: This patient has a symptom complex that is nonspecific but does suggest
some impairment of the balance system. Although she has a Chiari malformation by
imaging criteria, it is unlikely to be symptomatic, considering her history and the
lack of compression of posterior fossa structures.1 However, a physical examination
will be helpful in establishing whether a Chiari malformation could be causing some
or all of the patient’s symptoms (see Case 40). Because the patient benefited from
meclizine, she may have a vestibular system abnormality, a mild anxiety condition,
or both. From the information available, there are many conditions that are unli-
kely, including endolymphatic hydrops, benign paroxysmal positional vertigo,
migraine-related dizziness, and multiple sclerosis. It is unlikely that a definitive
diagnosis will be reached.

159
160 VESTIBULAR DISORDERS

Physical Examination

The patient’s general, neurologic, otologic, and neurotologic examinations were normal,
with the exception of some difficulty standing on a compliant foam surface with the eyes
closed. The patient’s gait had a slightly widened base.

Laboratory Testing

Videonystagmography: Ocular motor, positional, and caloric tests were normal.

A mild right directional preponderance was seen on rotational testing.
Posturography indicated minimally excessive sway on conditions 5 and 6.
VEMPs were normal.
The blood tests including metabolic, hematologic, rheumatologic, and thyroid tests
were normal.

Diagnosis/Differential Diagnosis

Question 2: Based on all of the information available, what diagnosis can be given to this
patient?
Answer 2: This patient does not have a well-defined disease process. This patient’s
evaluation does not suggest a symptomatic Chiari malformation (see Case 40).
Based upon the history and laboratory abnormalities, the patient could be given the
diagnosis of vestibulopathy of unknown origin. This is a diagnosis of exclusion, so it
must be remembered that other conditions that are difficult to rule out, such as
migraine, are possibilities. Follow-up care may allow a specific diagnosis.
This patient was given the diagnosis of nonspecific vestibulopathy.

TREATMENT/MANAGEMENT

Question 3: What are the treatment options for a patient with nonspecific vestibulopathy?
Answer 3: In patients in whom a specific diagnosis cannot be made but in whom
vestibular system involvement is highly suspected, treatment may consist of one or
more of the modalities listed in Case 16: Table 1. The decision to prescribe medica-
tion and, if so, which one, will depend on the physician’s judgment about the
importance and predominance of symptoms of nausea, dizziness, anxiety, depres-
sion, or an impairment of balance.2
Medications commonly used to decrease dizziness and nausea are listed in
Chapter 8: Table 1 and Chapter 8: Table 2. Note that these medications have
multiple effects. Specifically, medications used to decrease nausea may also reduce
dizzines, and drugs used to decrease dizziness often have anti-nausea properties.

Case 16: Table 1 Treatment Modalities for Nonspecific Vestibulopathy

Antinausea agents
Vestibular-suppressant agents
Antianxiety agents
Antidepressants
Vestibular rehabilitation therapy
 CASE 16: NONSPECIFIC VESTIBULOPATHY 161

Some patients respond favorably to anti-anxiety or antidepressant medications

even when their complaints of dizziness are quite prominent. We have also found
that adding a sympathomimetic agent such as pseudoephedrine to agents that
cause lethargy, such as promethazine hydrochloride, can be useful. In our experi-
ence, prochlorperazine should be reserved for patients with acute vestibular symp-
toms, such as those experienced during the very early stages of vestibular neuritis or
during a severe episode of endolymphatic hydrops. We have found little use for
transdermal scopolamine in patients with vestibulopathy. In addition to the mini-
mal relief provided, there is frequently a complaint of anticholinergic side effects
including blurred vision, which may actually worsen the symptoms of dizziness. Also,
discontinuation of scopolamine can be problematic.
The patient was given oral clonazepam, 0.25 mg twice daily. She was also
referred for vestibular rehabilitation. She had some relief of symptoms but contin-
ued to experience mild dizziness and disequilibrium.

SUMMARY

A 30-year-old woman presented with nonspecific dizziness and disequilibrium of a constant

nature with periodic exacerbations. The patient’s evaluation did not reveal a specific
diagnosis but suggested a vestibular system abnormality that could not definitely be
localized to the central or peripheral vestibular system. Treatment was therefore symptomatic.
The patient was given oral clonazepam, 0.25 mg twice daily. She was also encouraged to
increase her physical activity. She had some relief of symptoms but continued to experience
mild dizziness and disequilibrium.

TEACHING POINTS

1. Vestibulopathy of unknown origin and nonspecific vestibulopathy are terms used to

describe a complex of nonspecific symptoms that suggest some impairment of the
balance system but do not fit any recognized vestibular syndromes.
2. Nonspecific vestibulopathy is a diagnosis of exclusion. Conditions that should be
considered and ruled out include Meniere’s disease (endolymphatic hydrops), benign
paroxysmal positional vertigo, migraine-related dizziness, anxiety and panic disorders,
and potential central nervous system abnormalities such as multiple sclerosis, Chiari
malformation, or neoplasm. Follow-up care is important because a specific diagnosis
may become evident over time.
3. Treatment options for nonspecific vestibulopathy include medications and a
course of vestibular rehabilitation therapy. The decision to prescribe medication,
and, if so, which one, depends on the physician’s judgment about the importance and
predominance of symptoms of nausea, dizziness, anxiety, depression, or an impairment
of balance. Medications commonly used to decrease dizziness, vertigo, and nausea are
listed in Case 8: Table 1 and Case 8: Table 2.

References
1. Weber PC, Cass SP: Neurotologic manifestation of Chiari 1 malformation. Otolaryngol Head
Neck Surg 109:853–860, 1993.
2. Cass SP: Role of medications in otological vertigo and balance disorders. Semin Hearing
12:257–269, 1991.
Case 17
Benign Recurrent Vertigo of
Childhood

History

A 13-year-old boy presented with a chief complaint of 4 months of dizziness occurring

once or twice each week. The patient described a spinning sensation associated with a
feeling of imbalance and a tendency to fall. He also noted that if he disregarded these
symptoms and continued his normal activities, he became nauseated and on two occasions
had vomited. The patient had no complaint of hearing loss or tinnitus and did not describe
fullness in the ears. His school performance was excellent, but he had experienced some
recent difficulty in gym class and in performing extracurricular sports.
Question 1: Based on the patient’s history, what are the diagnostic considerations?
Answer 1: By far the most common cause of episodic vertigo in childhood is benign
recurrent vertigo of childhood,1–3 also known as benign paroxysmal vertigo of child-
hood, which is believed to have a migrainous basis.2 Infrequently, endolymphatic
hydrops (see Cases 9, 16, 21, 25) can be present in childhood. Less likely disorders
include perilymphatic fistula (see Case 52), a seizure disorder (see Case 47), and an
anxiety disorder (see Case 5). Benign paroxysmal positional vertigo (see Cases 7,
22, 25, 31, 39) should not be confused with benign recurrent vertigo of childhood;
the former is rare in children. Unusual metabolic abnormalities such as ornithine
transcarbamylase deficiency4 can present with episodic dizziness, as can familial
periodic ataxia. Structural lesions in the posterior fossa, including mass lesions, and
malformations such as a Chiari malformation would not be expected to produce
episodic symptoms but should be excluded.
Question 2: What further historical information will be helpful in establishing a diagnosis
of benign recurrent vertigo of childhood?
Answer 2: Associated historical features often include motion sickness, an apparent
relationship between vertiginous episodes, and certain foods such as aged cheese
and chocolate, possibly because of their tyramine or phenylethylamine (vasoactive
amines) content;4 and a positive family history of migraine. Patients may also be
bothered by certain visual environments such as flickering candles or open spaces.5

162
 CASE 17: BENIGN RECURRENT VERTIGO OF CHILDHOOD 163

Additional History

The patient had a history of car sickness, especially when riding in the back seat. He did not
notice a particular association between dizziness episodes and diet. There was a strong
family history of migraine on the maternal side; the patient’s mother and maternal aunt
suffered from throbbing headaches associated with photophobia, phonophobia, and nau-
sea. Also, the patient’s mother remembered having car sickness and avoiding amusement
parks during her childhood.

Physical Examination

The patient’s general, neurologic, otologic, and neurotologic examinations were normal.

Laboratory Testing

Videonystagmography test results were normal.

Rotational testing revealed a left directional preponderance.
Audiometry testing was scheduled because of the possibility of endolymphatic hydrops
or some other associated cochlear abnormality. The results were normal.
MRI scanning of the brain, which had been ordered by the patient’s pediatrician, was
normal.
Question 3: Are the vestibular laboratory findings in this patient consistent with a
diagnosis of benign recurrent vertigo of childhood?
Answer 3: This patient’s laboratory studies suggest an ongoing vestibulo-ocular
imbalance without evidence of peripheral vestibular involvement. Moreover, there
was no evidence of auditory system involvement or of a structural abnormality of
the central nervous system. Taken together, these findings make the diagnosis of
benign recurrent vertigo of childhood most likely. Although Basser’s original
description of benign recurrent vertigo of childhood3 suggested that unilateral
caloric reduction was important in making this diagnosis, subsequent studies
have not suggested this as a diagnostic criterion.6 A review of vestibular laboratory
findings in patients with migraine suggests that a directional preponderance on
rotation is a common finding (see Case 8).7–9

Diagnosis/Differential Diagnosis

This patient was diagnosed as having benign recurrent vertigo of childhood, presumably a
manifestation of a migrainous disorder.

Treatment/Management

The patient was advised to reduce his intake of foods known to provoke migraine10 (see
Case 17: Table 1). He responded well to this intervention, and the frequency and severity of
his attacks were markedly reduced. Medications effective in treating childhood migraine,
such as propranolol, periactin, calcium channel blockers, and anticonvulsants, could also
have been tried.2
164 VESTIBULAR DISORDERS

Case 17: Table 1 Foods That May Provoke Migraine

Foods containing tyramine

Aged cheeses, especially cheddar
Chicken liver
Dried smoked fish
Pickled herring
Red wine and wine vinegar
Sour cream
Yeast extracts
Yogurt
Artificial sweeteners, e.g., aspartamine
Avocado
Banana
Beans
Caffeine (excess, withdrawal)
Chocolate
Citrus fruits
Dairy products
Food additives, e.g., food coloring
Monosodium glutamate
Nitrates (e.g., in hot dogs, luncheon meats)
Nuts
Onions
Source: Adapted with permission from American Council for
Headache, Constantine LM, Scott S: Migraine: The Complete
Guide. New York: Dell, 1994, p 66.10

SUMMARY

A 13-year-old boy presented with episodic vertigo associated with nausea and two episodes
of vomiting. The patient had a history of car sickness and a family history of migraine. The
MRI scan and the audiometry test were normal. Vestibular laboratory testing showed a
normal caloric test and vestibulo-ocular asymmetry on rotational testing. The patient was
given a diagnosis of benign recurrent vertigo of childhood. Treatment consisted of dietary
restriction of migraine-provoking foods. The patient responded well to this intervention;
the frequency and severity of his attacks were markedly reduced.

TEACHING POINTS

1. Causes of episodic vertigo in childhood include benign recurrent (paroxysmal)

vertigo of childhood, endolymphatic hydrops, perilymphatic fistula, seizure
disorder, and anxiety disorder. Several metabolic, anatomic, and degenerative
disorders may also present with episodic dizziness. These include ornithine
transcarbamylase deficiency, cranial-cervical junction malformations such as Chiari
malformation, and familial periodic ataxia.
2. Benign recurrent vertigo of childhood is the most common cause of vertigo in
childhood and is probably a childhood manifestation of migraine. The diagnosis of
benign recurrent vertigo of childhood is established by the presence of episodic vertigo
 CASE 17: BENIGN RECURRENT VERTIGO OF CHILDHOOD 165

in a child without auditory symptoms in conjunction with associated historical features

such as motion sickness sensitivity, an apparent relationship between vertiginous
episodes and certain foods such as aged cheese and chocolate, and a positive family
history of migraine.
3. Vestibular test results in benign recurrent vertigo of childhood usually include
evidence of an ongoing vestibulo-ocular imbalance without evidence of peripheral
vestibular involvement. Unilateral caloric reduction is sometimes found but is not an
essential feathure of this diagnosis. Directional preponderance on rotational testing is a
common finding.
4. Treatment of benign recurrent vertigo of childhood includes the identification and
avoidance of dietary triggers. Potentially beneficial medications that may be tried in
more severe cases include propranolol, periactin, amitriptyline, and topiramate.

References

1. Russell G, Abu-Arafeh I: Paroxysmal vertigo in children—an epidemiological study. Int J

Pediatr Otorhinolaryngol 49(Suppl 1):S105–S107, 1999.
2. Abu-Arafeh I, Russell G: Paroxysmal vertigo as a migraine equivalent in children:
A population-based study. Cephalalgia 15(1):22–25, 1995.
3. Basser L: Benign paroxysmal vertigo of childhood. Brain 87:141–152, 1964.
4. Hockaday JM (ed): Migraine in Childhood. London: Butterworths, 1988.
5. Davidoff RA: Migraine: Manifestations, Pathogenesis, and Management. Philadelphia: FA
Davis, 1995.
6. Lanzi G, Balottin U, Fazzi E, Tagliasacchi M, Manfrin M, Mira E: Benign paroxysmal vertigo
of childhood: A long follow-up. Cephalalgia 14:458–460, 1994.
7. Toglia J, Thomas K, Kuritzky A: Common migraine and vestibular function
electronystagmographic study and pathogenesis. Ann Otol 90:267–271, 1981.
8. Kayan A, Hood J: Neuro-otological manifestations of migraine. Brain 107:1123–1142,
1984.
9. Cass SP, Furman JM, Ankerstjerne K, Balaban C, Yetiser S, Aydogan B: Migraine-related
vestibulopathy. Ann Otol Rhinol Laryngol 106(3):182–189, 1997.
10. American Council for Headache, Constantine LM, Scott S: Migraine: The Complete Guide.
New York: Dell, 1994.
Case 18
Drug-Induced
Dysequilibrium

History

An 83-year-old woman presented with dizziness and imbalance that was noticed during the
previous year without a clear date of onset. Dizziness symptoms were nearly constant
though nonspecific. Symptoms were exacerbated by movement and fatigue and improved
though not eliminated by sitting or lying still. The patient’s disequilibrium was also
nonspecific. Although the patient had not fallen, she seemed prone to falls based on reports
by her family members who insisted on accompanying the patient whenever she went
outdoors. There was no complaint of spinning and in particular no complaint of positional
vertigo. Past medical history was significant for hypertension, coronary artery disease, and
difficulty sleeping.
Question 1: What are the diagnostic considerations for this patient?
Answer 1: The differential diagnosis for this patient is broad and includes both
vestibular and nonvestibular entities. Benign paroxysmal positional vertigo (BPPV)
should be considered despite the absence of a complaint of positional dizziness as
this occurs frequently in older persons. Many older persons with BPPV do not
complain of positional dizziness.

Additional History

The patient provided a list of medications that included a beta blocker, a calcium channel
blocker, amiodorone, alprazolam, and trazadone.
Question 2: Based on the additional history, what other diagnostic considerations should
be entertained?
Answer 2: This older patient may be suffering from the effects of polypharmacy,
which may be entirely responsible for her symptoms or may be exacerbating an
underlying vestibulopathy.

166
 CASE 18: DRUG-INDUCED DYSEQUILIBRIUM 167

Physical Examination

General examination was normal with exception of mild orthostatic hypotension: blood
pressure and pulse when seated were 130/80 and 75 and when standing were 125/70 and 80.
The patient was mildly symptomatic when standing. Neurologic examination revealed
gaze-evoked nystagmus and a slowed, wide-based gait. Otologic examination was normal.
Neurotologic examination revealed a normal Dix-Hallpike maneuver.

Laboratory Testing

The patient had discontinued alprazolam, and trazadone for 2 days prior to testing and was
found to have normal ocular motor testing, no positional nystagmus, bilaterally reduced but
not absent caloric responses, and reduced rotational gain.
Vestibular evoked myogenic potentials were also reduced but not absent bilaterally.
Audiometric testing revealed a mild bilateral high frequency sensorineural hearing loss.
Magnetic resonance imaging showed minimal periventricular white matter hyperinten-
sities on T2-weighted images.
Question 3: Based upon the history, physical examination, and laboratory testing, what are
the diagnostic considerations?
Answer 3: This older patient appears to be suffering primarily from the effects of
multiple medications1, 2 in combination with what is frequently found in older
individuals, namely, a mild reduction in vestibular function bilaterally and periven-
tricular white matter disease on MRI. That is, the patient has a mild bilateral
vestibular reduction and an element of disequilibrium of aging. There is no evi-
dence of BPPV.
Question 4: What types of medication can cause dizziness?
Answer 4: Many types of medication can cause dizziness and disequilibrium includ-
ing anticonvulsants, antiarrhythmic medications, antihypertensive medications,
psychoactive medications, and even medications that are prescribed specifically
for dizziness. Examples of anticonvulsants that may cause dizziness or disequili-
brium include diphenylhydantoin, phenobarbital, carbamazepine, primidone, and
benzodiazepines. Anti-hypertensive agents that may cause dizziness include beta
blockers, possibly as a result of orthostatic hypotension. The side effects of these
medications can be additive and particularly problematic in older patients.
Question 5: What medications, when discontinued, can cause dizziness and disequili-
brium?
Answer 5: Discontinuation of selective serotonin reuptake inhibitors3 and benzodia-
zepine4 derivatives is associated with a withdrawal syndrome characterized, in part,
by dizziness and disequilibrium. Rapid discontinuation of scopolamine, which is
frequently prescribed for motion sickness, may be associated with extreme dizziness.5

Diagnosis/Differential Diagnosis

This patient was given a diagnosis of drug-induced dizziness in combination with a mild
reduction of vestibular sensitivity.
168 VESTIBULAR DISORDERS

Treatment

Treatment for this patient consisted of limiting her use of alprazolam and trazadone. Also,
both the patients’ primary care physician and her cardiologist were contacted and asked to
consider adjusting her anti-hypertensive and anti-arrhythmic medications to reduce her
dizziness and improve her balance. The patient was also referred to a physical therapist for
balance rehabilitation.

Follow-Up

When seen in follow-up 3 months later, the patient was much improved regarding both
dizziness and imbalance although she was not entirely asymptomatic regarding her dizzi-
ness and was noted to have somewhat slow gait.

Summary

An 83-year-old woman presented with constant dizziness and imbalance. There was
unsteadiness and no vertigo. Medications included a beta blocker, a calcium channel
blocker, amiodorone, alprazolam, and trazadone. Physical examination was essentially
normal. Laboratory testing indicated a mild reduction in vestibular function bilaterally and
periventricular white matter disease on MRI. The patient was given a diagnosis of drug-
induced dizziness. Treatment consisted of limiting the patient’s use of alprazolam and
trazadone and working with her other physicians to adjust medications.

Teaching Points

1. The side effects of medications should always be considered as a possible cause of

dizziness or disequilibrium. The most common medications to consider are
anticonvulsant, anti-hypertensive, anti-arrhythmic, and psychoactive medications.
2. Dizziness caused by the side effect of a medication can be additive with dizziness
caused by other medications or other medical conditions, such as a vestibulopathy,
especially in older patients.

References
1. Hartikainen S, Lonnroos E, Louhivuori K: Medication as a risk factor for falls: Critical
systematic review. Gerontol A Biol Sci 62(10):1172–1181, 2007.
2. Ziere G, Dieleman JP, Hofman A, Pols HA, van der Cammen TJ, Stricker BH: Polypharmacy
and falls in the middle age and elderly population. British J of Clin Pharm, 61(2):218–223,
2006.
3. Therrien F, Markowitz JS: Selective serotonin reuptake inhibitors and withdrawal symptoms:
A review of the literature. Hum Psychopharmacol Clin Exp 12(4):309–323, 1997.
4. Mintzer RZ, Stoller KB, Griffiths RR: A controlled study of flumazenil-precipitated
withdrawal in chronic low-dose benzodiazepine users. Psychopharmacology 147(2):200–209,
1999.
5. Feder RE: Letter to the editor: Transdermal scopolamine withdrawal syndrome. Clinical
Neuropharm 22(2):120, 1999.
Case 19
Cerebellar Degeneration

History

A 65-year-old man presented with a gradually worsening course of disequilibrium and gait
instability. The patient did not complain of vertigo, hearing loss, or tinnitus. His problem
had been present for at least 5 years and possibly for as long as 10 years, with gradually
increasing difficulty with balance while walking, especially on uneven surfaces while
hunting. He did not notice any particular worsening of his balance in dimly lit environ-
ments. There was some exacerbation of symptoms with rapid head movements. There were
no symptoms with position change. The patient had no medical history of importance and
used no medication. His family history was significant; his mother, who died in her early
80s, had suffered from a gradually worsening balance problem and became wheelchair-
bound in her middle to late 70s.
Question 1: Based on the patient’s history, what are the diagnostic considerations and
what further historical information would be helpful?
Answer 1: This patient has a nonspecific balance complaint. There is little in the
history to suggest a peripheral vestibular process. Rather, the patient’s complaint of
abnormal gait suggests a central nervous system, possibly a cerebellar disorder.
Further, the gradual worsening of the patient’s problem suggests a degenerative
disorder, especially because of the positive family history, but a mass lesion must
also be considered. A multisensory disequilibrium should also be considered,
although there is nothing in the history that suggests sensory system involvement.
It would be helpful to learn more about the patient’s ethanol use and any
information regarding toxic exposures. A more detailed family history would also
be helpful.

Further History

The patient denied significant ethanol consumption. There was no medical history of
pancreatitis, seizures, or cirrhosis of the liver. The family history was significant; his mother
and maternal uncle had had a late-onset balance disorder. The patient’s older brother was
killed in the armed forces, and his 60-year-old sister had no balance complaints.

169
170 VESTIBULAR DISORDERS

Physical Examination

The patient had no postural hypotension. Neurologic examination revealed full extraocular
movements. However, pursuit tracking was not smooth, and a bilateral horizontal gaze-
evoked nystagmus was seen. Motor examination was normal. Coordination testing showed
very mild abnormalities of rapid alternating movements, finger-to-nose movements, and
heel-knee-shin movements. Sensation was normal. The patient’s gait was extremely wide
based, and the patient was ataxic and unable to tandem walk. He had great difficulty
standing with his feet together even with his eyes open, so Romberg’s test could not be
performed. Otologic examination was normal. Neurotologic examination revealed no
spontaneous nystagmus, a normal head thrust, and no positional or positioning nystagmus.
Stance on foam could not be assessed.
Question 2: Based on the history and physical examination, what laboratory tests would
provide further information regarding this patient’s problems?
Answer 2: The patient’s history and physical examination suggest a central nervous
system abnormality, probably affecting the cerebellum. Diagnostic considerations
include cerebellar degeneration (unlikely to be due to alcoholism) and a posterior
fossa mass lesion. Other conditions to be considered, although unlikely, include
vasculitis, a paraneoplastic process,1 or a structural abnormality such as a Chiari
malformation. Thus, MRI of the brain with special attention to the posterior fossa is
appropriate. Additionally, vestibular laboratory testing specifically to assess cere-
bellar function should be considered.

Laboratory Testing

Videonystagmography: Ocular motor testing revealed normal velocity saccades with over-
shoot dysmetria, impaired pursuit, dysrhythmic optokinetic nystagmus, that is, irregular
quick component generation, and no spontaneous nystagmus.
Rotational testing indicated symmetric responses of high-normal response amplitude with
an abnormally large phase lead. Nystagmus dysrhythmia, that is, an irregular pattern of quick
and slow components of nystagmus, was also noted on rotational testing. Visual–vestibular
interaction testing (see Chapter 4) was abnormal in that there was difficulty suppressing
vestibular responses while viewing a head-fixed target during sinusoidal rotation, and the
magnitude of the nystagmus during rotation while viewing earth-fixed stripes was not
significantly greater than the magnitude of nystagmus elicited by rotation in darkness.
Posturography indicated moderately excessive sway in all conditions in a nonspecific
pattern.
An MRI scan of the brain showed midline cerebellar degeneration (Case 19 Figure 1).
There was obvious involvement of the anterior cerebellar vermis and a suggestion of loss of
tissue in the caudal midline cerebellum. No other abnormalities were seen on the MRI scan.
The screening blood studies including hematologic, metabolic, rheumatologic, and
thyroid studies were normal.
Question 3: Under what circumstances is visual–vestibular interaction testing useful?
Answer 3: Visual–vestibular interaction testing is useful as an adjunct to quantitative
vestibular laboratory testing when information is needed regarding the patient’s
ability to modify vestibular reflexes with vision. Visual–vestibular interaction is a
particularly sensitive measure when searching for evidence of an abnormality of
 CASE 19: CEREBELLAR DEGENERATION 171

(a) (b)

Case 19: Figure 1 Note on this sagittal MRI scan that the midline cerebellum is atrophied
(arrow). The cerebellar vermian sulci are larger than normal (A). Normal Comparison (B).

the vestibulocerebellum.2 Although most patients with abnormalities of visual–

vestibular interaction also have abnormalities of ocular pursuit, several studies
have indicated that visual–vestibular interaction provides information beyond
that which can be obtained from measuring pursuit.3 In this patient’s case, abnormal
visual–vestibular interaction confirms the suspicion of abnormal central vestibular
processing and suggests involvement of the cerebellar flocculus in the degeneration
syndrome.

Diagnosis/Differential Diagnosis

Question 4: Based on the history, physical examination, and laboratory studies, what is the
localization of this patient’s abnormality and what is its likely etiology?
Answer 4: The patient’s history, physical examination, and laboratory studies all
point toward an abnormality of cerebellar function. The MRI scan documents loss of
midline cerebellar tissue, and quantitative laboratory testing documents ocular
motor and vestibulo-ocular abnormalities. The most likely diagnosis is adult-onset
cerebellar degeneration. Because saccades were of normal velocity and there were
no corticospinal tract findings on neurologic examination, this patient does not
have olivopontocerebellar atrophy. Given the family history, the patient appears to
have a dominantly inherited form of parenchymal cerebellar atrophy.
The patient was given the diagnosis of adult-onset cerebellar degeneration,
probably dominantly inherited.
Question 5: What are the clinical and genetic features of the dominantly inherited ataxias,
and what role might genetic testing have in this patient?
Answer 5: There are numerous dominantly inherited spinocerebellar ataxias (SCA)
that have been identified clinically and genetically. Case 19: Table 1 lists the SCAs
Case 19: Table 1 Clinical Features of the Autosomal Dominant Spinocerebellar Ataxias

Disorder Distinguishing Features Gene Locus and Protein

SCA1 Pyramidal signs, peripheral neuropathy 6p22 CAG repeats, ataxin-1

SCA2 Slow saccades; less often myoclonus, 12q24 CAG repeats, ataxin-2
areflexia
SCA3 Slowsaccades, persistent stare, 14q32 CAG repeats, ataxin-3 (MJD1)
(MJD) extrapyramidal signs, peripheral
neuropathy
SCA4 Sensory neuropathy 16q22
SCA5 Early onset but slow progression 11q13.2 Beta III spectrin
SCA6 May have very late onset, mild, may lack 19p13 CAG repeats, alpha 1A P/Q
family history, nystagmus calcium channel subunit
SCA7 Macular degeneration 3p12 CAG repeats, ataxin-7
SCA8 Mild disease 13q21 CTG repeats, ?antisenseRNA
SCA9 Not categorized
SCA10 Generalized or complex partial seizures 22q13 ATTCT repeats
SCA11 Mild disease 15q14
SCA12 Tremor, dementia 5q31-q33 CAG repeats in 50 region,
protein phosphatase 2A
SCA13 Mental retardation 19q13 Voltage gated potassium
channel KCNC3
SCA14 Intermittent myoclonus with early onset 19q13 Protein kinase C gamma
disease
SCA15 Slowly progressive 3p24.2-
3pter
SCA16 Broad range of onset, head tremor 8q22.1-
24.1
SCA17 Gait ataxia, dementia 6q27 CAG repeats, TATA binding
protein
SCA18 Pyramidal signs, weakness, sensory 7q22-q32
axonal neuropathy
SCA19 Cognitive impairment; allelic with 1p21-q21
SCA22
SCA20 Palatal tremor and dysphonia 11p13-
q11
SCA21 Extrapyramidal signs 7-21.3-
p15.1
SCA22 Allelic with SCA19 1-21-q23
SCA23 Distal sensory deficits 20p13-
p12.3
SCA24 Recessive inheritance; redesignated as 1p36
SCAR4
SCA25 Sensory neuropathy, facial tics, 2p21-p13
gastrointestinal symptoms
SCA26 Pure cerebellar ataxia 19p13.3
SCA27 Cognitive impairment 13q34 Fibroblast growth factor 14
SCA28 Ophthalmoparesis and ptosis 18p11.22-
q11.2
DRPLA Chorea, seizures, myoclonus, dementia 12p CAG repeats, atrophin-1
16q22.1 Decreased muscle tone 16q22.1 Puratrohin I
MJD: Machado-Joseph disease; DRPLA: Dentatorubral pallidoluysian atrophy; SCA: Sinocerebellar ataxia
Source: From 2009 UpToDate, Inc,4 with permission.

172
 CASE 19: CEREBELLAR DEGENERATION 173

currently identified, with some of their clinical and genetic features. Another cere-
bellar disorder whose genetic basis has been elucidated is episodic ataxia type II
(EA 2), which presents with primarily episodic cerebellar dysfunction.5 This patient
does not clearly fit the picture of any of the known disorders on a purely clinical
basis. While genetic testing may uncover a specific genetic abnormality, there are
no known treatments that would be based on such information. A recent study
suggests that the severity of ataxia correlates inversely with cerebellar volume.6

Treatment/Management

The patient was treated by discontinuation of vestibular-suppressant medications, a home

safety consultation, and referral to a physical therapist for gait training. These measures
were associated with a slight improvement in the patient’s balance.7 A consultation with a
human geneticist was suggested.

Summary

A 65-year-old man presented with a gradually worsening course of disequilibrium and gait
instability. The patient’s complaints did not suggest a peripheral vestibular disorder. The
family history was positive for a late-onset balance disorder. Examination suggested
cerebellar system abnormalities. Brain imaging showed midline cerebellar degeneration.
Vestibular laboratory testing indicated abnormal visual–vestibular interaction. The patient
was given the diagnosis of adult-onset cerebellar degeneration, probably dominantly
inherited. Symptomatic treatment consisted of vestibular rehabilitation therapy and dis-
continuation of vestibular-suppressant medication.

Teaching Points

1. A neurodegenerative disorder should be considered in patients with a gradual

onset and worsening of imbalance in the absence of vertigo. Other diagnostic
considerations for patients with progressively severe symptoms include a posterior
fossa mass lesion, vasculitis, a paraneoplastic process, or a structural abnormality
such as a Chiari malformation. If a degeneration syndrome is suspected, a family
history should be obtained to determine whether other family members have had
similar difficulties.
2. Cerebellar degeneration may be associated with pontine abnormalities. Thus,
patients should be examined carefully for signs of pontine involvement such as
slowing of saccadic eye movements and for signs of corticospinal tract involvement.
In this way, it can be determined whether they have an isolated olivocerebellar
degeneration or olivopontocerebellar atrophy because pontine involvement causes
saccadic slowing and corticospinal tract signs. This categorization may be important
because olivopontocerebellar atrophy has a worse prognosis than olivocerebellar
degeneration.
3. Vestibular laboratory manifestations of cerebellar dysfunction may include
saccadic dysmetria, impaired pursuit and optokinetic nystagmus, and nystagmus
dysrhythmia, that is, an irregular pattern of quick components of nystagmus.
174 VESTIBULAR DISORDERS

4. Visual–vestibular interaction testing in the vestibular laboratory provides a

quantitative assessment of the patient’s ability to modify vestibular reflexes with
vision. Visual–vestibular interaction is a particularly sensitive measure when searching
for evidence of an abnormality of the vestibulocerebellum, particularly the flocculus.
Although most patients with abnormalities of visual–vestibular interaction also have
abnormalities of ocular pursuit, several studies have indicated that visual–vestibular
interaction provides information beyond that which can be obtained from measuring
pursuit.
5. Several different genetic abnormalities have been discovered that cause domi-
nantly inherited sca. Unfortunately, genetic testing has no treatment implications at
this time but may provide valuable information nonetheless.

References

1. Dalmau JG, Gilberto R, Lerwill MF: Case records of the Massachusetts General Hospital.
Case 4-2007. A 56-year old woman with rapidly progressive vertigo ataxia. N Engl J Med
356(6):612–620, 2007.
2. Baloh RW, Honrubia V: Clinical Neurophysiology of the Vestibular System, ed. 3. New York:
Oxford University Press, 2001.
3. Chambers BR, Gresty MA: The relationship between disordered pursuit and vestibulo-ocular
reflex suppression. J Neurol Neurosurg Psychiatry 46:61–66, 1983.
4. Opal P, Zoghbi HY: The spinocerebellar ataxias, UptoDate, 2009.
5. Baloh RW, Yue Q, Furman JF, Nelson SF: Familial episodic ataxia: Clinical heterogeneity in
four families linked to chromosome 19p. Ann Neurol 41:8, 1997.
6. Richter S, Dimitrova A, Maschke M, Gizewski E, Beck A, Aurich V, Timmann D: Degree of
cerebellar ataxia correlates with three-dimensional MRI-based cerebellar volume in pure
cerebellar degeneration. Eur Neurol 54(1):23–27, 2005.
7. Brown KE, Whitney SL, Marchetti GF, Wrisley DM, Furman JM: Physical therapy for central
vetibular dysfunction. Arch Phys Med Rehabil 87(1):76–81, 2006.
Part IV

Multiple Diagnosis Case Studies

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Case 20
Meniere’s Disease and
Migraine-Related Dizziness

History

A 57-year-old woman presented with the complaints of vertigo, right-sided hearing loss,
right-sided tinnitus, and right-sided ear fullness that had been occurring intermittently
during the previous 2 years. The patient had been evaluated by an otolaryngologist, who
diagnosed Meniere’s disease. She was treated with a combination of hydrochlorothiazide
and triamterene and was advised to reduce her sodium intake. The patient had a history of
headaches that worsened while taking the prescribed diuretics, so she discontinued the
medication. Her episodes of vertigo, hearing loss, and tinnitus typically lasted for about 30
minutes and were associated with nausea and occasional vomiting. Until recently, the
patient was essentially asymptomatic between episodes. However, during the previous
6 months, she noted intermittent disequilibrium usually associated with headache. The
patient indicated that this disequilibrium was not at all like her prior episodes of vertigo,
which continued to occur approximately once every 2 months. During the episodes of
disequilibrium, she also noted a rocking sensation that was exacerbated by lying down.
Bending her head forward or engaging in physical activity also worsened symptoms, which
included nausea and veering of her gait to the right. Preceding one of the patient’s episodes
was an aura of flashing lights. Prior to the onset of her episodic disequilibrium 6 months
prior to evaluation, the patient suffered from severe headaches every few months.
Recently, however, the headaches had lessened in severity, increased in frequency, and
were often associated with disequilibrium. Aside from the visual aura noted above, there
was no complaint of changes in vision and no complaint of numbness, weakness, or
alteration in level of consciousness. The patient’s medical history was significant for
hypertension not currently requiring treatment. The family history was significant; her
mother had had migraine headaches, and a paternal uncle had experienced dizziness of
unknown cause.
Question 1: Based upon the patient’s history, what are the diagnostic considerations?
Answer 1: The patient’s history is consistent with both Meniere’s disease and
migraine-related dizziness. Her history of episodic vertigo accompanied by unilat-
eral hearing loss, tinnitus, and ear fullness virtually assures a diagnosis of Meniere’s
disease (see Cases 9, 12, 24, 42). The patient’s more recent complaint of episodic
disequilibrium in association with headache strongly suggests migraine-related

177
178 VESTIBULAR DISORDERS

dizziness (see Case 8). Other diagnostic considerations such as benign paroxysmal
positional vertigo (see Cases 7, 23, 24, 25, 26, 28, 39) or a structural lesion of the
central nervous system seem unlikely.
Question 2: What are the diagnostic problems associated with the combination of
Meniere’s disease and migraine-related dizziness?
Answer 2: Both Meniere’s disease and migraine-related dizziness are associated with
episodic vestibular symptoms. In fact, Neuhauser et al.1 suggested that the diag-
nostic criteria for migrainous vertigo include episodic vestibular symptoms of
moderate severity such as rotational vertigo or other illusory self or object motion.
Thus, because the defining characteristics of Meniere’s disease and migraine-
related dizziness overlap, it may be difficult or impossible in some patients to reach
a definitive diagnosis based on the history alone.2,3 Another problem in diagnosis is
overlap in the situations that can exacerbate symptoms. Patients with migraine-
related dizziness may experience head motion intolerance and sensitivity to visual
motion. The same complaints can be seen in some patients with Meniere’s disease
between attacks. Another issue is that of disease onset. In patients with combined
Meniere’s disease and migraine-related dizziness, the onset of these disorders may
not occur simultaneously. In fact, most patients manifest one condition prior to the
other, as in this patient, who suffered from typical Meniere’s disease–related symp-
toms for 18 months before manifesting migraine-related dizziness. Still another
issue is synergy. Attacks of Meniere’s disease may serve as a trigger for migraine and
migraine-related dizziness. This phenomenon would obviously preclude defining
whether a particular episode was related solely to Meniere’s disease or migraine-
related dizziness.
Studies have indicated an increased incidence of migraine in patients with
Meniere’s disease4 and an increased incidence of hearing loss and tinnitus in
patients with migraine5 and basilar artery migraine,5 suggesting that there is
more than a chance co-occurrence of these disorders.

Physical Examination

Neurologic and otologic examinations were normal. Neurotologic examination revealed no

spontaneous nystagmus and a normal head thrust. Dix-Hallpike testing disclosed no signs
or symptoms with the left ear down. However, with the right ear down, the patient
experienced a sense of dizziness without vertigo or nystagmus. While standing on a
foam pad with her eyes closed, the patient complained of feeling dizzy and displayed
unsteadiness, but she did not lose her balance.

Question 3: Based upon the additional information from the physical examination, what
are the diagnostic considerations for this patient?
Answer 3: The patient’s physical examination is nonspecific but suggests ongoing
balance problems due to the symptoms experienced during Dix-Hallpike testing
and during assessment of postural sway on a compliant surface. Benign parox-
ysmal positional vertigo was absent. Also, the patient’s normal neurologic exam-
ination argues against a structural central nervous system lesion. Thus, the
patient is likely to be suffering from both Meniere’s disease and migraine-related
dizziness.
 CASE 20: MENIERE’S DISEASE AND MIGRAINE-RELATED DIZZINESS 179

Laboratory Testing

Videonystagmography revealed normal ocular motor function, no positional nystagmus,

and a right reduced vestibular response of 35%.
Rotational testing revealed a mild right directional preponderance.
Audiometric testing revealed a low-frequency sensorineural hearing loss on the right.
Hearing on the left was normal.
VEMPs were reduced on the right
An MRI scan was normal.
Question 4: Based upon the information available from the history, physical examination,
and laboratory testing, what are the most likely diagnostic considerations?
Answer 4: The laboratory tests support a diagnosis of right-sided Meniere’s disease
because of both the reduced caloric response and the low-frequency sensori-
neural hearing loss on the right. However, several studies have indicated that a
unilateral caloric reduction can be seen in patients with migraine-related dizzi-
ness.5–7 The asymmetric rotational responses could be based on the patient’s
Meniere’s disease. Alternatively, this laboratory abnormality could support the
diagnosis of migraine-related dizziness. Note that the asymmetry is in the oppo-
site direction from that seen with acute peripheral vestibular lesions. Thus,
laboratory testing supports the diagnosis of Meniere’s disease, migraine-related
dizziness, or both.

Diagnosis/Differential Diagnosis

The patient was given the diagnosis of a combination of Meniere’s disease and migraine-
related dizziness.

Treatment

Question 5: What are the treatment issues in a patient with the diagnosis of Meniere’s
disease and migraine-related dizziness?
Answer 5: The issues that pertain to the treatment of any patient with two diagnoses
are (1) whether to treat one disorder prior to treating the other or whether to treat
both simultaneously and (2) the conflicts, if any, between the treatments for the
two disorders. In patients with both Meniere’s disease and migraine-related dizzi-
ness, it is prudent to treat both disorders simultaneously. The treatment for
Meniere’s disease includes a salt-restricted diet of 2,000 mg of sodium per day
and a diuretic. Typically, these remedies have no effect on a patient’s migraine-
related dizziness. In fact, as noted above, successful treatment of Meniere’s disease
in a patient who also has migraine-related dizziness may reduce the migraine-
related dizziness due to a reduction of Meniere’s disease–related vertiginous epi-
sodes, which may act as potential migraine triggers. The medications used for the
treatment of migraine, and in particular migraine-related dizziness, would not be
expected to exacerbate or interfere with the treatment of Meniere’s disease.
This patient was treated for Meniere’s disease with a low-sodium diet and
another trial of a diuretic. She was also treated for migraine-related dizziness by
180 VESTIBULAR DISORDERS

being told to reduce her dietary intake of foods that might be provoking migraine7
and by prescribing clonazepam, 0.25 mg orally twice a day, and sertraline, 25 mg
orally at hour of sleep.
Question 6: How is this patient’s prognosis affected by having two balance disorders,
Meniere’s disease and migraine-related dizziness?
Answer 6: It is not known whether the combination of Meniere’s disease and
migraine-related dizziness influences the natural history or efficacy of the treatment
for these disorders. In our experience, as patients improve, both disorders are often
reduced.

Follow-Up

The patient was reevaluated 3 months following the initial assessment. She had experi-
enced only a single brief episode of true vertigo. Her disequilibrium also was improved but
persisted. The patient was referred for vestibular rehabilitation, which led to further
improvement but not complete alleviation of her imbalance.

Summary

A 57-year-old woman presented with the complaints of vertigo, right-sided hearing loss,
right-sided tinnitus, and right-sided ear fullness that had been occurring intermittently
during the previous 2 years. During the previous 6 months, the patient noted intermittent
disequilibrium usually associated with headache. She indicated that this disequilibrium
was not at all like her prior episodes of vertigo, which continued to occur approximately
once every 2 months. The family history was significant for migraine headaches. Physical
examination was nonspecific but suggested an ongoing balance problem. Videonystag-
mography revealed a right reduced vestibular response. The MRI scan was normal. The
patient was given the diagnosis of a combination of Meniere’s disease and migraine-related
dizziness. She was treated for both conditions.

Teaching Points

1. Both Meniere’s disease and migraine-related dizziness are associated with episodic
vestibular symptoms. Because the defining characteristics of these conditions overlap,
it may be difficult or impossible in some patients to reach a definitive diagnosis based
on the history alone.
2. A unilateral caloric reduction can be seen in patients with Meniere’s disease and in
patients with migraine-related dizziness. Also, asymmetric rotational responses can
be due to migraine-related dizziness or a recent episode of Meniere’s disease.
3. For patients with both Meniere’s disease and migraine-related dizziness, it is
prudent to treat both disorders simultaneously.
4. It is not known whether the combination of Meniere’s disease and migraine-
related dizziness influences the natural history or efficacy of treatment for these
disorders.
 CASE 20: MENIERE’S DISEASE AND MIGRAINE-RELATED DIZZINESS 181

References
1. Neuhauser H, Leopold M, von Brevern M, Arnold G, Lempert T: The interrelations of
migraine, vertigo, and migrainous vertigo. Neurology 56:436–441, 2001.
2. Dimitri PS, Wall C, Oas JG, Rauch SD: Application of multivariate statistics to vestibular
testing: Discriminating between Meniere’s disease and migraine associated dizziness. J Vestib
Res 11(1):53–65, 2001.
3. Shepard NT: Differentiation of Meniere’s disease and migraine-associated dizziness: A
review. J Amer Academy of Audiolgy 17(1):69–80, 2006.
4. Rassekh CH, Harker LA: The prevalence of migraine in Meniere’s disease. Laryngoscope
102:135–138, 1992.
5. Kayan A, Hood JD: Neuro-otological manifestations of migraine. Brain 107:1123–1142,
1984.
6. Olsson JE: Neurotologic findings in basilar migraine. Laryngoscope 101(Suppl 52):1–41,
1991.
7. Cass SP, Furman JM, Ankerstjerne JKP, Balaban C, Yetiser S, Aydogan B: Migraine-related
vestibulopathy. Ann Otol Rhinol Laryngol 106:182–189, 1997.
Case 21
Head Trauma: Combined
CNS, Labyrinthine, and
Cervical Injury

History

A 50-year-old man construction worker complained of dizziness for 4 months. The patient
dated the onset of his symptoms to a motor vehicle accident in which the vehicle that he was
driving was struck from behind. He was not wearing a restraint device and struck his head
against the steering wheel. There was a brief loss of consciousness at the time of the accident.
The patient was evaluated at a local emergency room, where a CT scan of the brain was
reportedly negative. Although the patient was released from the emergency room, he experi-
enced dizziness and neck pain immediately following the accident and visited his primary
care physician the next day. He was prescribed meclizine, which provided some but inade-
quate relief of his dizziness. Subsequently, the patient returned to his primary care physician
with complaints of headache, neck pain, and imbalance. He was referred to a physical
therapist for his neck pain and was advised to wear a soft cervical collar on an as-needed
basis. These measures provided some additional relief, but the patient was dissatisfied.
Question 1: Based on the patient’s history, what is his differential diagnosis?
Answer 1: This patient’s history suggests a vestibular system disorder that may have
been caused by a labyrinthine concussion, a neck injury, or possible brainstem
concussion. Labyrinthine concussion (see Case 13) is most likely because the
patient struck his head and experienced dizziness immediately following head
trauma. Cervicogenic dizziness (see Case 58) is a possibility because of the patient’s
neck pain following a presumed whiplash (i.e., flexion-extension) injury. A brain-
stem or cerebellar concussion is possible given the patient’s history of head trauma
followed by headache and his persistent symptoms that suggest impaired vestibu-
lar compensation.

Additional History

The patient noted exacerbation of dizziness with rapid head movements but not when
turning in bed. Also, symptoms were not exacerbated by Valsalva maneuvers. He did not

182
 CASE 21: HEAD TRAUMA: COMBINED CNS, LABYRINTHINE, AND CERVICAL INJURY 183

complain of hearing loss or tinnitus. The patient had no prior complaints of dizziness and
no significant medical history.

Physical Examination

On general examination, the patient exhibited limited head movement except forward
flexion but was otherwise normal. Neurologic and otologic examinations were normal.
Neurotologic examination using infrared goggles revealed no spontaneous nystagmus, an
abnormal head thrust to the right, a low-amplitude left-beating nystagmus following head
shake, negative Dix-Hallpike maneuvers, an inability to stand on a compliant foam pad
with the eyes closed, no pastpointing, and no nystagmus during hyperventilation, tragal
stimulation, Valsalva maneuver, and pneumatic otoscopy. Cervico-ocular testing could not
be performed because of the patient’s limited range of motion of the head on the trunk. Gait
was mildly unsteady.
Question 2: Based upon the additional information, what is this patient’s likely diagnosis?
Answer 2: Based upon the patient’s history and physical examination, he appears to
have suffered from a labyrinthine concussion on the right and incomplete vestibular
compensation. The patient’s abnormal head thrust suggests a peripheral vestibular
injury on the right and is consistent with a labyrinthine concussion. Incomplete
vestibular compensation is suggested by the persistence of post-head-shake nys-
tagmus, an abnormal stepping test, and inability to stand on a compliant foam pad
with the eyes closed. The patient’s incomplete compensation may be based upon
the nature of his labyrinthine injury (i.e., aberrant vestibular function), an associated
traumatic brainstem or cerebellar injury (i.e., a concussion), or his neck injury. Thus,
the patient may be suffering from a combined labyrinthine, central nervous system,
and cervical injury. There is no evidence of benign paroxysmal positional vertigo or
perilymphatic fistula.

Laboratory Testing

Videonystagmography: Ocular motor testing revealed symmetrically impaired ocular pur-

suit and optokinetic nystagmus. A left-beating spontaneous nystagmus of 3 degrees per
second using infrared goggles was noted. There also was a low amplitude left-beating
persistent positional nystagmus. Caloric irrigation revealed an absent response to warm
and cool irrigation in the right ear. A minimal response was elicited with ice-water
irrigation of the right ear.
Rotational testing revealed a mild to moderate left directional preponderance.
Posturography indicated excessive sway on conditions 5 and 6.
Vestibular evoked myogenic potentials were reduced on the right.
Audiometric testing revealed a bilateral high-frequency sensorineural hearing loss.
Word recognition was normal bilaterally.
A CT scan of the brain, ordered by the patient’s primary care physician, was normal.
Question 3: Based upon the patient’s laboratory tests, what is the most likely diagnosis?
Answer 3: The patient’s laboratory tests further support the idea that the patient has
suffered a labyrinthine concussion (see Case 13) on the right with impaired vestib-
ular compensation (see Case 3). Also, the patient’s abnormal ocular motor testing
suggests the possibility of a brainstem or cerebellar concussion.
184 VESTIBULAR DISORDERS

Diagnosis/Differential Diagnosis

The patient was given the diagnosis of a combined labyrinthine concussion and brainstem/
cerebellar concussion with possible cervicogenic dizziness.
Question 4: What are the implications of a combined injury to the ear, brain, and neck?
Answer 4: With combined injuries, there is increased diagnostic uncertainty.
Moreover, a combination of injury to the ear, brain, and neck increases the
likelihood that the patient will experience impaired compensation because of
damage to central nervous system structures important for compensation and
because of the probable role of neck afferents. Moreover, abnormal vestibular
function is likely to cause abnormal neck muscle activity, which in turn can
lead to increased pain and abnormal neck afferent activity, resulting in
ongoing exacerbation of dizziness and neck discomfort. Also, the patient’s
decreased range of motion of the head on the trunk may itself interfere with
vestibular compensation and provide an additional challenge for vestibular
rehabilitation.

Treatment/Management

Question 5: Based upon the patient’s tentative diagnoses, what are the treatment options?
Answer 5: The treatment modality most likely to be helpful is vestibular rehabilita-
tion focused on the patient’s vestibular loss, impaired compensation, decreased
range of motion of the head, and neck pain. The use of pharmacotherapy is
challenging because vestibular-suppressant medications and muscle relaxants
may interfere with the process of vestibular compensation.
The patient was treated with a combination of vestibular rehabilitation and
diazepam, 1 mg twice daily, on an as-needed basis. Meclizine was discontinued.
The patient was advised to continue physical therapy for his neck.

Follow-Up

The patient’s symptoms gradually decreased, but he was unable to return to his occupation
as a construction worker because of continued imbalance.
Question 6: What are the implications for prognosis for patients with combined injuries of
the ear, brain, and neck?
Answer 6: Patients with combined injuries of the ear, brain, and neck have a poorer
prognosis than patients with isolated injuries.1 In particular, such patients require a
longer period of time for recovery, require more therapy sessions, and are likely to
have a persistent disability.

Summary

A 50-year-old man complained of 4 months of dizziness that began following a motor

vehicle accident in which he struck his head against the steering wheel and experienced
brief loss of consciousness. The patient’s history, physical examination, and laboratory
 CASE 21: HEAD TRAUMA: COMBINED CNS, LABYRINTHINE, AND CERVICAL INJURY 185

tests suggested a combined labyrinthine, central nervous system, and cervical injury.
Treatment consisted of vestibular rehabilitation, physical therapy for his neck, and diaze-
pam on an as-needed basis.

Teaching Points

1. Head trauma, especially that caused by motor vehicle accidents, can lead to
combined injury of the labyrinth, central nervous system, and neck.
2. Combined injury of the labyrinth, central nervous system, and neck can cause
impaired vestibular compensation. Combined injury can also lead to increased
symptoms, particularly related to the neck, as compared to isolated abnormalities.
3. Treatment of patients with combined labyrinth, central nervous system, and neck
abnormalities should address the cervical and labyrinthine components of the
problem. Vestibular rehabilitation is the primary therapy. Pharmacotherapy should
be tailored to maximize symptom reduction and minimize interference with vestibular
compensation.
4. The prognosis for patients with combined labyrinth, central nervous system, and
neck abnormalities is less favorable than that of patients with isolated
abnormalities.

Reference
1. Cass SP, Borello-France D, Furman JF: Functional outcome of vestibular rehabilitation in
patients with abnormal sensory-organization testing. Am J Otol 4:581–594, 1996.
Case 22
Migraine-Related Dizziness
and Anxiety Disorder

History

A 56-year-old woman presented with a 3-month complaint of dizziness and disequili-

brium. She stated that during the preceding 3 months she had three discrete episodes of
the sudden onset of vertigo, rapid heartbeat, faintness, cold sweating, anxiety, and
seeing visual spots. These episodes lasted for about 5 minutes and were followed by a
sensation of swimming in her head, unsteadiness, and nausea. The patient’s other
complaints, which did not occur in discrete episodes, included fluctuating bilateral
tinnitus and bilateral ear fullness. Complaints also included headaches characterized
by head pressure and an electric-like shock sensation in her scalp. During the head-
aches, she complained of seeing spots, photophobia, and phonophobia. Additional
complaints included occasional circumoral paresthesias and poor balance. The patient
related that she had been avoiding shopping malls and grocery stores for the previous
6 weeks. Her medical history was significant for fibromyalgia and irritable bowel
syndrome. The patient’s family history was significant; her father and brother had
migraine headaches.
Question 1: Based upon the patient’s history, what are the diagnostic considerations?
Answer 1: The patient’s history is consistent with migraine-related dizziness
(Case 8), an anxiety disorder (Case 5 and 25), and possibly a peripheral
vestibulopathy. The diagnosis of migraine-related dizziness is supported by the
episodic nature of the patient’s dizziness, the type of headaches from which the
patient suffers, and the patient’s positive family history of migraine. The diag-
nosis of an anxiety disorder is supported by the patient’s complaints of anxiety
during her dizziness episodes, circumoral paresthesias, and space and motion
discomfort.

Physical Examination

Neurologic and otologic examinations were normal. Neurotologic examination showed no

spontaneous nystagmus and a normal head thrust. There was no positional nystagmus, and

186
 CASE 22: MIGRAINE-RELATED DIZZINESS AND ANXIETY DISORDER 187

the Dix-Hallpike test was negative. The patient had increased sway while standing on a
compliant foam pad with the eyes closed.
Question 2: Based upon the patient’ s history and physical examination, what are the
diagnostic considerations?
Answer 2: The patient’s physical examination does not change the diagnostic
considerations except to reduce the likelihood of a peripheral vestibular ailment.
Thus, migraine-related dizziness and anxiety remain the most likely diagnoses.

LABORATORY TESTING

Videonystagmography revealed a normal ocular motor test and no positional nystagmus.

Shortly after the first caloric irrigation, the patient discontinued caloric testing. Similarly,
shortly after the start of rotational testing, the patient discontinued rotational testing.
Posturography revealed increased sway in a nonspecific pattern.
Audiometric testing was normal.
VEMPs were normal
Several months earlier, the patient had undergone MRI of the brain, which was normal.
Question 3: Based upon the patient’s history, physical examination, and laboratory tests,
what are the most likely diagnoses?
Answer 3: The patient’s laboratory tests provide little additional information
because the patient discontinued caloric and rotational testing. Patients with anxi-
ety often discontinue vestibular laboratory tests because of the aversive nature of
the stimulus. Posturography testing suggests a balance disorder but does not
provide diagnostic information. Thus, the patient is most likely suffering from a
combination of migraine-related dizziness and anxiety. The patient’s anxiety may,
in part, be induced by her dizziness. Alternatively, some of the patient’s dizziness is
directly related to her anxiety.
Question 4: Do symptoms of migraine-related dizziness and anxiety overlap with one
another and thus interfere with an accurate diagnosis of these conditions?
Answer 4: A diagnosis of migraine-related dizziness is based on criteria suggested
by Neuhauser et al.1 and include episodic vestibular symptoms. Some of the
symptoms of migraine-related dizziness overlap with symptoms attributable to
panic attacks, namely, episodic vertigo and dizziness. Also, both migraine and
anxiety occur in episodes that can be triggered, although for many episodes, a
specific trigger cannot be identified. In this patient, the diagnosis of migraine-
related dizziness is supported by the association of dizziness with headache, the
positive family history of migraine, and the absence of another identifiable neu-
rotologic syndrome. The diagnosis of anxiety disorder is supported by the
patient’s complaints of presyncope, anxiety, and circumoral paresthesias.
Despite these distinct diagnostic aspects, the etiology of the three discrete epi-
sodes is uncertain. They may have been attacks of migraine-related dizziness,
panic attacks, or a combination of both. That is, they may have begun as
migraine-related or anxiety-related symptoms and then evolved into a combined
migrainous and anxiety-related episode. Moreover, the patient’s space and
motion discomfort could be related to either her migraine-related dizziness, her
anxiety, or both.
188 VESTIBULAR DISORDERS

Diagnosis/Differential Diagnosis

This patient was given a tentative diagnosis of combined migraine-anxiety-related dizzi-

ness (MARD).
Question 5: What treatment should be considered for a patient with both \parmigraine-
related dizziness and an anxiety disorder, i.e., MARD?
Answer 5: Patients with migraine-anxiety-related dizziness should be treated for
both conditions. The optimal treatment for migraine-related dizziness is not
known. However, such patients are typically treated with the same medications
that are used to treat migraine headache, which include antidepressants. They
may also benefit from low-dose benzodiazepines for symptomatic relief.
Pharmacotherapy for anxiety includes benzodiazepines and antidepressants.
Thus, a combination of a benzodiazepine and an antidepressant is particularly
warranted in patients with migraine-anxiety-related dizziness. Also, two recent
studies suggest that vestibular rehabilitation may benefit both patients with
migraine-anxiety-related dizziness2 and patients with anxiety-related dizziness.3
Thus, vestibular rehabilitation also seems particularly appropriate for patients with
migraine-anxiety-related dizziness.

Treatment

The patient was treated with a combination of clonazepam 0.25 mg, orally twice a day, and
imipramine, 25 mg orally at hour of sleep. The patient was also referred for vestibular
rehabilitation.

Follow-Up

The patient improved markedly and no longer experienced episodic dizziness. However, she
continued to experience nonlateralized tinnitus, ear fullness, and visual motion sensitivity.
Question 6: Are migraine-related dizziness and anxiety interrelated?
Answer 6: A recent study by Breslau et al.4 indicates that migraine is more likely to
occur in patients with panic disorder, and panic disorder is more likely to occur in
patients with migraine. Further support for a relationship other than chance co-
occurrence is given in Case 22: Table 1, in which the odds ratio for anxiety disorders
is clearly higher in patients with migraine. Merikangas and Stevens5 suggest that

Case 22: Table 1 Association Between Migraine and Anxiety: Community Studies

Odds Ratio

Reference N Panic Phobia Generalized Anxiety Disorder Any Anxiety

Stewart et al.6 10,169 5.3 – – –

Merikangas et al.7 457 3.3 2.4 5.3 2.7
Breslau et al.8 1,007 6.0 1.9 5.3 1.9
Source: With permission from Merikangas KR, Stevens DE: Comborbidity of migraine and psychiatric disorders. Neurol Clin
15(1):115–123, 1997.5
 CASE 22: MIGRAINE-RELATED DIZZINESS AND ANXIETY DISORDER 189

the co-occurrence of panic disorder and migraine is complex and bidirectional

rather than one condition simply increasing the risk of the other. They suggest
that shared environmental or genetic factors or overlapping neurotransmitter sys-
tems may explain the co-occurrence of migraine and panic disorder. An article by
Furman et al9 postulates a neuroanatomical and neurochemical basis for migraine-
anxiety-related dizziness.
Question 7: What psychiatric disorders have been associated with migraine?
Answer 7: Although no information is available specifically regarding migraine-
related dizziness, there is an increased incidence of anxiety, depression, and social
fears in patients with migraine headache.5

Summary

A 56-year-old woman presented with a 3-month complaint of dizziness and disequilibrium.

She had three discrete episodes of vertigo, rapid heartbeat, faintness, cold sweating,
anxiety, and seeing visual spots lasting for 5 minutes followed by a sensation of swimming
in her head, unsteadiness, and nausea. She also complained of fluctuating bilateral tinnitus
and ear fullness. Other complaints included headaches, head pressure, an electric-like
shock sensation in her scalp, seeing spots, photophobia, phonophobia, circumoral par-
esthesias, and poor balance. The patient’s family history was significant for migraine
headache. Physical examination was normal, with the exception of increased sway while
standing on a compliant foam pad. Laboratory testing was incomplete because the patient
discontinued caloric and rotational testing. Posturography revealed increased sway in a
nonspecific pattern. She was given a diagnosis of migraine-anxiety-related dizziness. The
patient was treated with a combination of clonazepam, imipramine, and vestibular rehabi-
litation. The patient no longer experienced episodic dizziness but continued to experience
nonlateralized tinnitus, ear fullness, and visual motion sensitivity.

Teaching Points

1. Patients with anxiety often discontinue vestibular laboratory testing because of the
aversive nature of the stimulus.
2. Symptoms of migraine-related dizziness and of anxiety may overlap, creating
diagnostic uncertainty.
3. Patients with migraine-anxiety-related dizziness (MARD) should be treated for
both conditions. A combination of benzodiazepines and antidepressants should be
considered, as should vestibular rehabilitation.
4. Migraine is more likely to occur in patients with panic disorder, and panic disorder
is more likely to occur in patients with migraine. This relationship may be based upon
shared environmental or genetic factors or overlapping neurotransmitter systems.
5. There is an increased incidence of anxiety, depression, and social fears in patients
with migraine.

References
1. Neuhauser H, Leopold M, von Brevern M, Arnold G, Lempert T: The interrelations of
migraine, vertigo, and migrainous vertigo. Neurology 56(4):436–441, 2001.
190 VESTIBULAR DISORDERS

2. Whitney SL, Wrisley DM, Brown KD, Furman JM: Physical therapy for migraine-related
vestibulopathy and vestibular dysfunction with history of migraine. Laryngoscope
110(9):1528–1534, 2000.
3. Jacob RG, Whitney SL, Setweiler-Shostak G, Furman JM: Vestibular rehabilitation for
patients with agoraphobia and vestibular dysfunction: A pilot study. J Anxiety Disorders
15(1–2):131–146, 2000.
4. Breslau N, Schultz LR, Stewart WF, Lipton R, Welch KMA: Headache types and panic
disorder: Directionality and specificity. Neurology 56:350–354, 2001.
5. Merikangas KR, Stevens DE: Comorbidity of migraine and psychiatric disorders. Neurol Clin
15(1):115–123, 1997.
6. Stewart WF, Linet MS, Celentano DD: Migraine headaches and panic attacks. Physcosom
Med 51:559–569, 1989.
7. Merikangas KR, Angst J, Isler H: Migraine and psychopathology: Results of the Zurich cohort
study of young adults. Arch Gen Psychiatry 47:849–853, 1990.
8. Breslau N, Davis GC, Andreski P: Migraine, psychiatric disorders, and suicide attempts. An
epidemiologic study of young adults. Psychiatry Res 37:11–23, 1991.
9. Furman JM, Balaban CD, Jacob RG, Marcus DA: Migraine-anxiety related dizziness
(MARD): A new disorder? J Neurol Neurosurg Psychiatry 76(1):1–8, 2005.
Case 23
Benign Paroxysmal
Positional Vertigo and
Migraine-Related Dizziness

History

A 30-year-old woman who worked as a medical assistant presented with a complaint of

dizziness that occurred mostly with changes in position. Dizziness had been present for
more than 1 year intermittently but had increased in frequency and severity recently. The
patient’s symptoms fluctuated and were not present each day. A spinning sensation often
occurred at night when turning in bed. The patient had a history of migraine headaches and
noted a definite association between dizziness symptoms and migrainous symptoms
including headache, photophobia, and phonophobia. However, the patient also noted
positional symptoms even when not symptomatic with migrainous symptoms.
Question 1: What are the diagnostic considerations in this case and what further history
would be helpful?
Answer 1: This patient’s history suggests both benign paroxysmal positional vertigo
and migraine-related dizziness. The temporal association between migrainous
symptoms and dizziness symptoms suggests migraine-related dizziness. The posi-
tional symptoms, especially dizziness while turning in bed, suggests benign parox-
ysmal positional vertigo. Additional historical information of interest would include
any prior treatments for either BPPV or migraine and any information about exacer-
bating factors.

Additional History

Additional history revealed that the patient had been treated for migraine headaches in the
past with a beta-blocker, which had been helpful but was no longer felt to be required by her
primary care physician. Also, the patient related that positional dizziness independent of
headache was a more recent complaint. The patient’s symptoms were exacerbated by
exposure to complex visual environments such as shopping malls and grocery stores.
Otherwise, the patient indicated that she had been sleeping using several pillows to avoid
lying flat.

191
192 VESTIBULAR DISORDERS

Physical Examination

The patient’s general examination was normal. Neurologic examination was normal.
Otologic examination was normal. Neurotologic examination revealed no spontaneous
nystagmus, a normal head thrust test, and no difficulty standing on a complaint foam
pad even with eyes closed. However, Dix-Hallpike maneuvers revealed the typical
nystagmus and vertigo of benign paroxysmal positional vertigo with the right ear
down.

Laboratory Testing

Video nystagmography revealed normal ocular motor and caloric testing. There was a
direction changing persistent positional nystagmus of low amplitude.
Rotational testing revealed a left directional preponderance.
Posturography was normal.
Vestibular-evoked myogenic potentials were reduced on the right.
Audiometric testing was normal.
Question 2: Based on the history, physical examination, and laboratory testing, what is this
patient’s most likely diagnosis?
Answer 2: This patient is clearly manifesting benign paroxysmal positional
vertigo. However, the patient’s fluctuating complaints of dizziness related to
headache suggest that benign paroxysmal positional vertigo may represent
only a portion of the patient’s presentation. Specifically, the direction-chan-
ging persistent positional nystagmus and abnormal vestibular-evoked myo-
genic potentials suggest a more widespread vestibular system abnormality.
Migraine-related dizziness is a likely diagnosis to account for the patient’s
symptoms and signs that cannot be accounted for by benign paroxysmal
positional vertigo.
Question 3: Is there an association, if any, between benign paroxysmal positional vertigo
and migraine-related dizziness?
Answer 3: Benign paroxysmal positional vertigo has been reported in association
with migraine-related dizziness. Although the association is not strong, the litera-
ture suggests that the co-occurrence of these two conditions is seen more often
than would be expected by chance alone.1, 2 Moreover, many patients with
migraine-related dizziness complain of positional dizziness without positional ver-
tigo.3 The pathophysiology of positional dizziness associated with migraine-related
dizziness is uncertain but does not appear to be related to either cupulolithiasis or
canalithiasis.

Diagnosis/Differential Diagnosis

The patient was given the diagnoses of both benign paroxysmal positional vertigo and
migraine-related dizziness.
CASE 23: BENIGN PAROXYSMAL POSITIONAL VERTIGO AND MIGRAINE-RELATED DIZZINESS 193

Treatment

Question 4: What treatments should be considered for patients with a combination of

benign paroxysmal positional vertigo and migraine-related dizziness?
Answer 4: The patient should be treated with a particle repositioning maneuver
appropriate for posterior semicircular canal benign paroxysmal positional vertigo.
Further treatment considerations will depend upon the frequency and severity of
the patient’s symptoms once there has been successful treatment for the benign
paroxysmal positional vertigo. The patient should be advised to avoid dietary intake
of foods that might provoke migraine such as caffeine (see Case 8). Also, the patient
should be scheduled for a follow-up appointment at which time pharmacotherapy
and possibly vestibular rehabilitation should be considered.

Follow-Up

The patient was seen in follow-up in 6 weeks at which time her symptoms had diminished to
their baseline of approximately 1 year earlier. That is, every few weeks the patient experi-
enced dizziness usually associated with headache or photophobia/phonophobia. This dizzi-
ness included a worsening when lying in certain positions. The patient had not missed work
because of her symptoms. The patient was advised that migraine abortive therapy with a
triptan and symptomatic treatment with a vestibular suppressant on an as-needed basis were
treatment considerations. However, the patient did not wish to use medications at this time.

Summary

A 30-year-old woman presented with a complaint of dizziness that occurred mostly with
changes in position. A spinning sensation often occurred at night when turning in bed. The
patient had a history of migraine headaches and noted a definite association between dizziness
symptoms and migrainous symptoms. Dix-Hallpike maneuvers revealed benign paroxysmal
positional vertigo. The patient was given the diagnoses of both benign paroxysmal positional
vertigo and migraine-related dizziness. The patient was treated for both disorders.

Teaching Points

1. Patients may present with both benign paroxysmal positional vertigo and
migraine-related dizziness more often than would be expected by chance alone.
2. Positional dizziness may be seen with both benign paroxysmal positional vertigo
and migraine-related dizziness. The characteristics of these two types of positional
dizziness are quite different and usually can be distinguished from one another without
difficulty.
3. The treatment of patients with a combination of benign paroxysmal positional
vertigo and migraine-related dizziness should include treatment for both
disorders. Benign paroxysmal positional vertigo should be treated first and residual
symptoms assessed at a follow-up visit.
194 VESTIBULAR DISORDERS

References
1. Von Brevern M, Radtke A, Lezius F, Feldmann M, Ziese T, Lempert T, Neuhauser H:
Epidemiology of benign paroxysmal positional vertigo: A population based study. J Neurol
Neurosurg Psychiatry 78(7):663, 2007.
2. Uneri A: Migraine and benign paroxysmal positional vertigo: An outcome study of 476
patients. Ear Nose Throat J 83(12):814–815, 2004.
3. Neuhauser H, Lempert T: Vertigo and dizziness related to migraine: A diagnostic challenge.
Cephalagia 24(2):83–91, 2004.
Case 24
Meniere’s Disease and
Benign Paroxysmal
Positional Vertigo

History

A 63-year-old woman presented with the chief complaint of dizziness when rolling over in
bed. The patient noted that this type of dizziness began several months earlier and lasted for
only about 1 minute when turning toward the right while lying in bed. Symptoms were also
noticeable when looking up and occasionally when leaning forward. The patient was being
treated for Meniere’s disease affecting the right ear. Several years previously, she began
experiencing weekly episodes of vertigo, right-sided hearing loss, right-sided tinnitus,
right-sided ear fullness, nausea, and occasional vomiting. These episodes were sponta-
neous and typically were not associated with any particular activity. They lasted for about
30 minutes but were occasionally brief (i.e., only a few minutes) or more prolonged (i.e.,
several hours). The patient had been evaluated by an otolaryngologist, who diagnosed
Meniere’s disease and prescribed a diuretic and sodium restriction. The patient responded
well to this treatment, experiencing only brief (several minutes long) episodes every few
months. Then the patient began to experience positional vertigo. The patient’s medical
history was otherwise negative. Her only medication was a combination of hydrochlor-
othiazide and triamterene prescribed by her otolaryngologist. The family history was
noncontributory.
Question 1: Based upon the patient’s history, what is her diagnosis?
Answer 1: The patient’s history strongly suggests the combination of Meniere’s
disease and, more recently, benign paroxysmal positional vertigo. It is possible
that the patient’s positional symptoms are in some way related to her Meniere’s
disease, manifesting as pseudo–benign paroxysmal positional vertigo, that is, benign
paroxysmal positional vertigo–type postural nystagmus and vertigo caused by
disorders other than benign paroxysmal positional vertigo.1. Possibilities also
include a chance co-occurrence of Meniere’s disease and benign paroxysmal posi-
tional vertigo and an etiologic association via degenerative labyrinthine effects of
Meniere’s disease.

195
196 VESTIBULAR DISORDERS

Physical Examination

Neurologic examination was normal. Otologic examination revealed that on Weber’s test
the patient lateralized to the left. Neurotologic examination revealed no spontaneous
nystagmus, a normal head thrust, and excessive sway on a compliant foam surface even
with the eyes closed. On Dix-Hallpike testing, the patient had no signs or symptoms with
the left ear down. However, with the right ear down, the patient manifested typical signs
and symptoms of benign paroxysmal positional vertigo.
Question 2: Based upon the physical examination, what is this patient’s likely diagnosis?
Answer 2: The patient’s physical examination confirms the diagnosis of benign
paroxysmal positional vertigo affecting the right ear. Additionally, the abnormal
Weber test suggests a sensorineural hearing loss in the right ear, supporting a
diagnosis of Meniere’s disease. There were no central nervous system abnormalities
to suggest a neurologic diagnosis. The patient’s excessive sway while standing on a
compliant foam surface indicates a nonspecific abnormality.

Laboratory Testing

Videonystagmography revealed normal ocular motor function, no persistent positional

nystagmus, and a right reduced vestibular response on caloric testing of 50%. Rotational
testing was normal. Posturography was abnormal in a nonspecific pattern.
Audiometric testing revealed a low-frequency sensorineural hearing loss on the right.
Hearing was normal on the left. Word recognition was excellent bilaterally.
Question 3: Based upon the patient’s history, physical examination, and laboratory tests,
what are the likely diagnoses?
Answer 3: Laboratory testing indicates a reduced vestibular response and a low-
frequency sensorineural hearing loss on the right. These findings support a diag-
nosis of right-sided Meniere’s disease. Although laboratory testing is not typically
used to diagnose benign paroxysmal positional vertigo, a reduced caloric response
is commonly seen in patients with this condition.

Diagnosis/Differential Diagnosis

The patient was given the diagnoses of Meniere’s disease and benign paroxysmal posi-
tional vertigo.
Question 4: What diagnostic problems, if any, are caused by the co-occurrence of
Meniere’s disease and benign paroxysmal positional vertigo?
Answer 4: Meniere’s disease and benign paroxysmal positional vertigo generally
have different symptoms and signs. Meniere’s disease is characterized by sponta-
neous episodes, whereas specific head movements trigger benign paroxysmal
positional vertigo. Meniere’s disease generally lasts for minutes to hours, whereas
benign paroxysmal positional vertigo generally lasts less than 1 minute. Meniere’s
disease is accompanied by unilateral hearing loss and tinnitus, whereas benign
paroxysmal positional vertigo is not associated with abnormalities of hearing. The
 CASE 24: MENIERE’S DISEASE AND BENIGN PAROXYSMAL POSITIONAL VERTIGO 197

onset of Meniere’s disease frequently precedes the onset of benign paroxysmal

positional vertigo.2 Recurrence of benign paroxysmal positional vertigo may be
higher in patients with Meniere’s disease.3
Clinicians focused on vertigo in a patient with established Meniere’s disease may
not consider benign paroxysmal positional vertigo. Thus, given the increased
incidence of benign paroxysmal positional vertigo in patients with Meniere’s
desease, clinicians should check for benign paroxysmal positional vertigo even if
they do not highly suspect this diagnosis.

Treatment

Question 5: Should the treatment of benign paroxysmal positional vertigo in a patient with
coexisting Meniere’s disease be different from that of a patient without coexisting
Meniere’s disease? Should the treatment of Meniere’s disease in a patient with coexisting
benign paroxysmal positional vertigo be different from that of a patient without coexisting
benign paroxysmal positional vertigo?
Answer 5: Coexisting Meniere’s disease in general should not affect the use of
particle repositioning to treat benign paroxysmal positional vertigo. However,
treatment of refractory benign paroxysmal positional vertigo is affected by coexist-
ing Meniere’s disease since surgical approaches may be more likely to cause hearing
loss in an ear affected by Meniere’s disease. Also, coexisting benign paroxysmal
positional vertigo should not affect the choice of treatment for a patient with
Meniere’s disease.
The patient was treated with a particle repositioning maneuver (see Case 7) and
was asymptomatic on second Dix-Hallpike testing following the therapeutic man-
euver. The patient was advised to continue her treatment for Meniere’s disease.
Question 6: How might Meniere’s disease predispose a patient to develop benign parox-
ysmal positional vertigo?
Answer 6: Gross et al.2 hypothesized that Meniere’s disease may damage the otolith
organs, thereby releasing utricular otoconia into the endolymph.

Follow-Up

One week following particle repositioning, the patient returned with continued positional
vertigo. Another particle repositioning maneuver was repeated and was apparently suc-
cessful. However, the patient returned 2 weeks later with continued positional complaints.
Question 7: Is the patient’s recalcitrance to treatment in some way related to her Meniere’s
disease?
Answer 7: Gross et al.2 have noted that benign paroxysmal positional vertigo
associated with Meniere’s disease may be more difficult to treat than idiopathic
benign paroxysmal positional vertigo. Intractable benign paroxysmal positional
vertigo has been attributed, in some patients, to obstruction within the membra-
nous ducts of the posterior semicircular canal.4 The mechanism of such an obstruc-
tion is unknown, but in patients with associated Meniere’s disease, partial
obstruction of the posterior semicircular canal may be caused by a dilated saccule
or a stricture of the membranous labyrinth.2,3
198 VESTIBULAR DISORDERS

Question 8: What further treatment options should be considered?

Answer 8: Referral for vestibular rehabilitation would be appropriate. The therapist
will see the patient frequently in order to resolve the benign paroxysmal positonal
vertigo. Advising the patient to perform Brandt-Daroff exercises is also appropriate.

Summary

A 63-year-old woman presented with the chief complaint of dizziness when rolling over in
bed that is typical of benign paroxysmal positional vertigo. The patient was also being
treated for Meniere’s disease affecting the right ear. Physical examination confirmed the
diagnosis of benign paroxysmal positional vertigo affecting the right ear. Laboratory
testing supported a diagnosis of right-sided Meniere’s disease. The patient was treated
with a particle repositioning maneuver and was advised to continue her treatment for
Meniere’s disease. She returned with continued positional complaints that prompted a
referral for vestibular rehabilitation.

Teaching Points

1. Some patients suffer from Meniere’s disease and benign paroxysmal positional
vertigo simultaneously. Generally, the onset of Meniere’s disease precedes the onset of
the benign paroxysmal positional vertigo.
2. Coexisting Meniere’s disease does not affect the use of particle repositioning to
treat benign paroxysmal positional vertigo. Also, coexisting benign paroxysmal
positional vertigo does not affect the treatment for a patient with Meniere’s disease
3. Meniere’s disease may damage the otolith organs, thereby releasing utricular
otoconia into the endolymph, leading to benign paroxysmal positional vertigo.
4. Benign paroxysmal positional vertigo associated with Meniere’s disease may be
more difficult to treat than idiopathic benign paroxysmal positional vertigo.
Intractable benign paroxysmal positional vertigo has been attributed, in some
patients, to obstruction within the membranous ducts of the posterior semicircular
canal.3

References
1. Hughes CA, Proctor L: Benign paroxysmal positional vertigo. Laryngoscope 107:607–613,
1997.
2. Gross EM, Bradford BD, Viirre ES, Nelson JR, Harris JP: Intractable benign paroxysmal
positional vertigo in patients with Meniere’s disease. Laryngoscope 110:655–659, 2000.
3. Tanimoto H, Doi K, Nishikawa T, Nibu K: Risk factors for recurrence of benign paroxysmal
positonal vertigo. J Otolaryngol Head Neck Surg 37(6):832–835, 2008.
4. Parnes LS, Price-Jones R: Particle repositioning maneuver for benign paroxysmal positional
vertigo. Ann Otol Rhinol Laryngol 102:325–331, 1993.
Case 25
Benign Paroxysmal
Positional Vertigo and
Anxiety Disorder

History

A 39-year-old male salesman presented with the chief complaint of disequilibrium and
positional dizziness for the preceding 6 months. Symptoms had started abruptly following
a viral upper respiratory tract infection. The patient felt as if he were walking on a cloud.
Subsequently, he noted dizziness when looking up or turning in bed. He also related having
panic attacks several times each week. The patient had no prior psychiatric history and had
no recent changes in his family or work situation. His panic attacks were characterized by
dizziness, pounding in the chest, numbness and tingling in the fingers, difficulty breathing,
air hunger, sweating, nausea, and a fear that he might die. Besides having symptoms of
positional vertigo and intermittent panic attacks, the patient worried excessively about
having future attacks. He had mild disequilibrium that provoked fear and had discomfort in
certain environments such as shopping malls, grocery stores, and congested traffic. The
patient’s only medication was diazepam, 2 mg twice daily. The family history was not
contributory.
Question 1: Based upon the patient’s history, what diagnoses should be considered?
Answer 1: The patient’s history suggests the diagnosis of benign paroxysmal posi-
tional vertigo. It also suggests an anxiety disorder, specifically panic disorder. The
diagnosis of benign paroxysmal positional vertigo is suggested by the definite
positional nature of the patient’s complaints. Panic disorder is suggested by the
patient’s attacks of fearfulness associated with typical autonomic symptoms of
panic attacks. The patient’s complaints of discomfort in shopping malls and grocery
stores suggest space and motion discomfort (Chapter 7), which can be seen in
anxiety-prone individuals with vestibular disorders.

Physical Examination

Neurologic and otologic examinations were normal. Neurotologic examination revealed no

spontaneous nystagmus, a normal head thrust, and excessive sway without falling while

199
200 VESTIBULAR DISORDERS

standing on a compliant foam pad with the eyes closed. Dix-Hallpike testing with the left
ear down revealed no signs or symptoms. However, with the right ear down, the patient
complained of vertigo, and typical upbeating-torsional nystagmus of benign paroxysmal
positional vertigo was observed. However, within 10 seconds of reaching the head-hang-
ing-right position, the patient began to hyperventilate, and he demanded that the infrared
goggles he was wearing be removed and that he be returned to the seated position. Upon
returning to the seated position, the patient continued to hyperventilate for about 1 minute,
during which time he complained of symptoms comparable to those that he experienced
during his typical panic attacks.
Question 2: Based upon the patient’s physical examination, what are the diagnostic
considerations?
Answer 2: The patient’s physical examination confirms a diagnosis of right-sided
benign paroxysmal positional vertigo. Additionally, the patient’s emotional reac-
tion to Dix-Hallpike testing suggests that he has an anxiety disorder and that some,
if not all, of his panic attacks are induced by positional vertigo. Thus, the patient
appears to have a combination of benign paroxysmal positional vertigo and panic
disorder.

Laboratory Testing

Videonystagmography revealed normal ocular motor testing, no persistent positional

nystagmus, and a 30% right reduced vestibular response on caloric testing. The patient
could not tolerate optokinetic testing. Rotational testing revealed a mild left directional
preponderance although he completed testing at only two of the frequencies before
requesting that the test be discontinued. Square-wave jerks were noted throughout the
eye movement recordings.
VEMPs were present bilaterally.
Audiometric testing was normal.
Question 3: Based upon the patient’s history, physical examination, and laboratory test
results, what are the most likely diagnostic considerations?
Answer 3: The patient’s laboratory test results suggest that in addition to having
benign paroxysmal positional vertigo, a disorder that affects the posterior semicir-
cular canal, the patient has a mild reduction in the function of the left horizontal
semicircular canal. Moreover, the patient’s rotational test result suggests an
ongoing VOR asymmetry. The patient’s square-wave jerks are nonspecific and
possibly are related to anxiety. Thus, the diagnoses of benign paroxysmal positional
vertigo and panic disorder seem most likely. Moreover, the patient appears to have
a more widespread vestibular abnormality based upon caloric and rotational test-
ing. Note that attempting to assign a single diagnosis for this patient precludes
accurate diagnosis of both the neurotologic and psychiatric disorders.

Diagnosis/Differential Diagnosis

The patient was given the diagnoses of benign paroxysmal positional vertigo and an
anxiety disorder.
 CASE 25: BENIGN PAROXYSMAL POSITIONAL VERTIGO AND ANXIETY DISORDER 201

Question 4: What diagnostic problems, if any, must be considered in a patient who presents
with the combination of benign paroxysmal positional vertigo and anxiety?
Answer 4: As with all patients who present with two diagnoses, the issues of overlap
between signs and symptoms, the sequence of onset, and the interrelationship
between the disorders must be considered. For patients with benign paroxysmal
positional vertigo and anxiety, there is little difficulty discerning one condition from
the other. Although dizziness and vertigo occur in both disorders, the symptoms of
benign paroxysmal positional vertigo are clearly position related. Panic attacks are
associated with fear and a sense of impending doom not seen with uncomplicated
benign paroxysmal positional vertigo. The sequence of onset and the interrelation-
ship between benign paroxysmal positional vertigo and anxiety can be understood
in the context of the relationship between balance disorders and anxiety disorders,
which is discussed in Chapter 7. In this patient, benign paroxysmal positional
vertigo appears to be triggering the patient’s anxiety.1 Thus, a somatopsychic
mechanism seems most likely. The alternative possibilities of chance co-occurrence,
psychosomatic mechanisms, and neurologic linkage are all unlikely.

Treatment

Question 5: How should a patient with both benign paroxysmal positional vertigo and
panic disorder be treated?
Answer 5: In general, patients with two diagnoses should be treated for both
disorders. This holds true especially for patients with both a neurotologic disorder
and a psychiatric disorder. However, the issue of which treatment to institute first
must be considered. In this patient, because benign paroxysmal positional vertigo is
clearly acting as a trigger for panic attacks, the vertigo should be treated first. The
panic attack induced by Dix-Hallpike testing suggests that treatment with particle
repositioning may be challenging. Pretreatment with a benzodiazepine may be
necessary.2
The patient was treated with a particle repositioning maneuver about 15 minutes
following the ingestion of 5 mg of diazepam. Also, because of the patient’s more
widespread vestibular abnormalities, he was enrolled in a course of vestibular
rehabilitation.

Follow-Up

Following particle repositioning, the patient was much improved. He no longer suffered
from positional vertigo. Also, panic attacks ceased. However, the patient still experienced
mild nonspecific dizziness and a sense of imbalance. Moreover, he experienced discomfort
in shopping malls and grocery stores but did not avoid them.

Summary

A 39-year-old man presented with symptoms typical of benign paroxysmal positional

vertigo. He also complained of disequilibrium, panic attacks, and discomfort in certain
environments, such as shopping malls, grocery stores, and congested traffic. Physical
examination confirmed a diagnosis of right-sided benign paroxysmal positional vertigo.
202 VESTIBULAR DISORDERS

The patient had a panic attack during Dix-Hallpike testing. Laboratory testing revealed a
right reduced vestibular response on caloric testing and a mild left directional preponder-
ance on rotational testing. The patient was given the diagnoses of benign paroxysmal
positional vertigo and panic disorder. He was treated with a particle repositioning man-
euver following pretreatment with 5 mg diazepam and was enrolled in a course of
vestibular rehabilitation.
Following particle repositioning, the patient was much improved, with a resolution of
his positional vertigo and panic attacks. He continued to experience discomfort in shopping
malls and grocery stores but did not avoid them.

Teaching Points

1. When patients present with both benign paroxysmal positional vertigo and
anxiety, there is little difficulty in distinguishing one condition from the other.
Although dizziness and vertigo occur in both disorders, the symptoms of benign
paroxysmal positional vertigo are clearly position related. Panic attacks are associated
with fear and a sense of impending doom not seen with uncomplicated benign
paroxysmal positional vertigo.
2. Attempting to assign a single diagnosis to a patient with both a neurotologic
disorder and a psychiatric disorder precludes accurate diagnosis of both
disorders and may lead to suboptimal management.
3. When benign paroxysmal positional vertigo is clearly triggering panic attacks, the
vertigo should be treated first.
4. Patients with benign paroxysmal positional vertigo and an anxiety disorder may
require pretreatment with a benzodiazepine prior to performing a particle
repositioning maneuver.

References
1. Lilienfeld SO: Vestibular dysfunction followed by panic disorder with agoraphobia. J Nerv
Ment Dis 177:700–701, 1989.
2. Hain TC, Uddin M: Pharmacological treatment of vertigo. CNS Drugs 17(2):85–100, 2003.
Part V

Unusual Disease Case Studies

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Case 26
Recurrent Benign
Paroxysmal Positional
Vertigo—Nonsurgical
Management

History

A 65-year-old man presented with a complaint of dizziness when looking up and a history
of falls. The patient was very fearful of falling and related that his falls were associated with
changes in head position that provoked vertigo. One such occasion occurred while remov-
ing window curtains. The patient had a history of benign paroxysmal positional vertigo
(BPPV) treated with particle repositioning maneuvers six times in the prior 2 years. The
patient was concerned that he would continue to experience recurrences of BPPV asso-
ciated with imbalance and falls. This recurrent medical condition caused the patient and his
family significant distress. There was no medical history of hypertension or vascular
disease.
Question 1: What are the diagnostic considerations in this case?
Answer 1: This patient is apparently suffering from recurrent BPPV.1 There are no
other diagnostic considerations that are likely given the patient’s response to
particle repositioning.

Physical Examination

The patient’s general examination was normal. Neurologic examination was normal.
Neurotologic examination revealed no spontaneous nystagmus, a normal head thrust test,
and a positive Romberg test with the patient falling backward. The patient’s walking was
slow, tentative, and wide based. Dix-Hallpike maneuvers were performed despite the
patient’s fear of potentially experiencing vertigo. No vertigo or nystagmus was seen.
However, the patient complained of nonspecific dizziness, especially with the left ear
down.
Question 2: Based on the patient’s physical examination, are there additional diagnostic
considerations?

205
206 VESTIBULAR DISORDERS

Answer 2: The patient appears to have a history of BPPV not currently active.2 In
addition, the patient may be suffering from disequilibrium of aging given his
abnormal gait and a subclinical peripheral neuropathy given the positive
Romberg sign.

Laboratory Testing

Videonystagmography revealed normal ocular motor testing. There was no persistent posi-
tional nystagmus. Caloric testing revealed a left reduced vestibular response. Vestibular
evoked myogenic potentials were reduced on the left. A magnetic resonance imaging scan of
the brain indicated diffuse periventricular and deep white matter signal abnormalities con-
sistent with nonspecific small vessel ischemic disease.
Question 3: Based on the additional information from laboratory testing, what is this
patient’s most likely diagnosis?
Answer 3: This patient’s most likely diagnosis is a combination of a history of benign
paroxysmal positional vertigo affecting the left ear, a left peripheral vestibular loss of
uncertain etiology, and disequilibrium of aging. The patient clearly is suffering from
recurrent benign paroxysmal positional vertigo. Moreover, the patient’s gait
instability is likely a result of a combination of these three disorders.

Diagnosis/Differential Diagnosis

The patient was given the diagnoses of benign paroxysmal positional vertigo, unilateral
peripheral vestibular loss, and disequilibrium of aging.

Treatment

The patient was treated with vestibular rehabilitation therapy including particle reposition-
ing maneuvers as needed. Additionally, the patient was prescribed balance and gait
exercises as gait changes have been noted following particle repositioning.3

Follow-Up

The patient did well for several weeks. Unfortunately, however, after discontinuation of
physical therapy, the patient suffered a recurrence of dizziness and returned 4 months later
for reevaluation. The patient was noted to have a positive Dix-Hallpike maneuver on the
left at that time. The patient was accompanied by his granddaughter who lived near the
patient and asked specifically about home treatment for benign paroxysmal positional
vertigo. The patient and his granddaughter were taught home particle repositioning.4
Subsequently, the patient was able to undergo particle repositioning maneuvers at home
with success.
Question 5: Which patients are appropriate for home particle repositioning maneuvers and
what is the success rate of this treatment?
Answer 5: Not all patients are appropriate for home particle repositioning. It is
essential that patients are cognitively sound and can understand directions.
 CASE 26: RECURRENT BPPV—NONSURGICAL MANAGEMENT 207

Moreover, patients should have adequate motor abilities and no significant history
of vascular disease that would predispose to ischemia during repositioning. It is
preferable to have a family member present during home particle repositioning
instructions and to include that family member in the training process. The success
rate of home particle repositioning is nearly 90%.5

Summary

A 65-year-old man with a history of BPPV previously treated with particle repositioning
presented with a recurrence of symptoms. There was a history of falls. Dix-Hallpike testing
was normal. Vestibular laboratory testing showed a left reduced response. Imaging was
consistent with disequilibrium of aging. The patient was treated with vestibular rehabilita-
tion therapy including particle repositioning maneuvers as needed. He was prescribed
Brandt-Daroff exercises for habituation of nonspecific dizziness. Following another recur-
rence of symptoms, the patient was taught home particle repositioning, which were
successful.

Teaching Points

1. BPPV can recur frequently and can be responsive to particle repositioning

maneuvers for each recurrence.
2. Home maneuvers such as Brandt-Daroff maneuvers are not preventative for
recurrences of BPPV.
3. Treatment of BPPV at home using particle repositioning maneuvers that are self-
administered is a reasonable management technique for persons who have
sufficient intelligence and motor abilities and no significant history of vascular
disease. A family member should be present.
4. The success rate for home treatment of BPPV is relatively high.
5. Recurrent BPPV can cause significant psycho-social distress.

References

1. Brandt T, Huppert D, Hecht J, Krch C, Strupp M: Benign paroxysmal positioning vertigo:

A long-term follow-up (6–17 years) of 125 patients. Acta Otolaryngol 126(2):160–163, 2006.
2. Pollak L: The importance of repeated clinical examination in patients with suspected benign
paroxysmal positional vertigo. Otol Neurotol 30(3):356–358, 2009.
3. Celebisoy N, Bayam E, Gülec F, Köse T, Akyürekli O: Balance in posterior and horizontal
canal type benign paroxysmal positional vertigo before and after canalith repositioning
maneuvers. Gait Posture 29(3):520–523, 2009.
4. Radtke A, von Brevern M, Tiel-Wilck K, Mainz-Perchalla A, Neuhauser H, Lempert T:
Self-treatment of benign paroxysmal positional vertigo: Semont maneuver vs. Epley
procedure. Neurology 63(1):150–152, 2004.
5. Tanimoto H, Doi K, Katata K, Nibu KI: Self-treatment for benign paroxysmal positional
vertigo of the posterior semicircular canal. Evid Based Med 11(3):78, 2006.
Case 27
Orthostatic Hypotension

History

A 50-year-old man who worked as an electronics repairman complained of frequent

dizziness and lightheadedness that had gradually worsened over several years. He
rarely experienced vertigo. The patient’s symptoms included a sense of disequilibrium
and a feeling of generalized weakness and faintness. These symptoms were especially
noticeable on first arising and on standing for more than several minutes in one place.
The patient had no complaint of hearing loss, tinnitus, paresthesias, air hunger,
palpitations, fear, or anxiety. The family history was positive for adult-onset diabetes
mellitus and negative for neurologic or otologic disease. The patient stated that he had
recently been tested for blood sugar level and that this was normal. He was not using
medications.
Question 1: What are the diagnostic considerations in this case? What additional history
should be obtained? What special maneuvers, if any, should be performed during physical
examination?
Answer 1: This patient’s history provides little information for establishing a
definitive diagnosis of a peripheral or central vestibular disorder. In fact, the
symptoms of faintness and generalized weakness suggest a nonvestibular cause
for the patient’s dizziness. Disorders to be considered include hypotension, espe-
cially orthostatic hypotension, intermittent hyperventilation associated with anxi-
ety and/or a chronic anxiety state, hypoglycemia, anemia, hyperthyroidism or
hypothyroidism, and medication side effects.
The patient also has little to suggest an anxiety disorder. He indicated that he had
been checked for hypoglycemia and that this was negative. The patient should be
asked whether he had undergone blood studies for anemia and hypothyroidism.
During physical examination, blood pressure and pulse should be measured with
the patient supine and at 1, 3, and 5 minutes after standing.1

Additional History

The patient’s records indicated that a complete blood count, thyroid and adrenocortical
steroid function tests, and a screening electrolyte battery were normal.

208
 CASE 27: ORTHOSTATIC HYPOTENSION 209

Physical Examination

The patient’s examination revealed a blood pressure of 130/85 while he was supine, with a
pulse of 70. After 3 minutes of standing, his blood pressure was 90/60 and his pulse was 90.
The patient stated that he was experiencing his typical symptoms of faintness and asked to sit
down. He felt less symptomatic almost immediately on sitting.1 The remainder of the
neurologic examination was normal. During Romberg’s test, the patient complained of feeling
lightheaded, but he did not fall with his eyes closed and was able to stand on a compliant foam
surface without difficulty. The neurotologic and otologic examinations were normal.

Diagnosis/Differential Diagnosis

Question 2: Based on the patient’s history and physical examination, what is the probable
diagnosis?
Answer 2: This patient has orthostatic hypotension. Patients with this condition
become and remain dizzy when they move from a recumbent to an upright
position. Examination before and after this movement reveals a significant (>20
mm Hg)2 drop in systolic blood pressure when standing, often with a concomitant
increase (10 beats per minute) in heart rate. Non-neurogenic causes are associated
with an increase in heart rate of more than 15 beats per minute. Absence of an
increase in heart rate suggests a neurogenic cause. Blood pressure and heart rate
should be measured with the patient supine and after standing for 2 minutes. This
allows for differentiation between transient symptoms due to a sluggish barorecep-
tor response (common in the elderly) and true orthostatic hypotension. The
physical examination in this patient provided no evidence of vestibular system
disease. Blood studies ruled out several other diagnostic possibilities.

Laboratory Testing

Not Performed
Question 3: What are the characteristics of nonvestibular dizziness, and how do they differ
from the symptoms of vestibular-induced dizziness?
Answer 3: Patients with vestibular dizziness often complain of vertigo that may
include spinning or tilting and a sense of being off balance, whereas patients with
nonvestibular dizziness often complain of lightheadedness, a floating sensation, a
swimming sensation, or giddiness. Vestibular dizziness is often episodic and may
be constant. Nonvestibular dizziness is often constant. Vestibular dizziness is often
produced or exacerbated by rapid head movements and certain changes in
position, such as rolling over in bed. Symptoms associated with vestibular
disorders can include nausea, vomiting, unsteadiness, tinnitus, hearing loss,
impaired vision, and oscillopsia, whereas nonvestibular dizziness may be asso-
ciated with perspiration, palpitations, paresthesias, syncope or presyncope,
difficulty concentrating, and malaise.1 Unfortunately, there is much overlap
between vestibular and nonvestibular symptoms, so that it is difficult to make
such a distinction from the history alone.
This patient was given the diagnosis of idiopathic orthostatic hypotension.
210 VESTIBULAR DISORDERS

Question 4: What are the possible causes of orthostatic hypotension?

Answer 4: Orthostatic hypotension is not a specific disease but rather a manifesta-
tion of abnormal blood pressure regulation, which may be due to many different
causes. The most common cause is hypovolemia due to excessive use of diuretic
agents or other medications, including vasodilator agents (nitrate preparations and
calcium antagonists) and agents that impair autonomic reflex mechanisms (certain
anti-hypertensive drugs, monoamine oxidase inhibitors, antidepressants, phe-
nothiazine antipsychotic drugs, quinine, l-dopa, barbiturates, alcohol, and vincris-
tine). Orthostatic hypotension after prolonged bed rest may be due to decreased
baroreceptor responsiveness. Hypotension also may be a sign of underlying auto-
nomic system insufficiency, which can occur in several neurologic disorders. Signs
and symptoms of autonomic dysfunction include impotence, fecal and urinary
incontinence, iris atrophy, decreased sweating, decreased tearing, and decreased
salivation. When symptoms are confined to the autonomic nervous system, the
syndrome is referred to as pure autonomic failure. When other neurologic abnorm-
alities are present, the syndrome is called multiple system atrophy. In the latter
syndrome, there may be signs of cerebellar disease, parkinsonism, and corticobul-
bar tract dysfunction. Several other disorders that can cause orthostatic hypoten-
sion include diabetic neuropathy, amyloidosis, tabes dorsalis, syringomyelia,
pernicious anemia, alcoholic neuropathy, vasospastic disorders, and peripheral
vascular insufficiency.

Treatment/Management

This patient was treated with support stockings, abdominal binders,3 and increased dietary
sodium intake and fludrocortisone, 0.1 mg twice daily. He was also advised that when
changing from a supine to a standing position he should first activate the leg muscles before
arising slowly and, once upright, he should begin ambulation as soon as possible to avoid
standing in one place for more than a very brief time.
The patient responded favorably to this treatment but still experienced some dizziness
and lightheadedness when standing.

Summary

A 50-year-old man presented with the chief complaint of dizziness, especially when
standing, associated with a sense of faintness and lower-extremity weakness. The patient’s
examination revealed postural hypotension without evidence of vestibular system abnorm-
ality. The patient was treated with support stockings, increased dietary sodium, and
fludrocortisone, and experienced a reduction in symptoms.

TEACHING POINTS

1. Dizziness of vestibular origin and dizziness of nonvestibular origin cannot be

distinguished easily from one another.
2. Patients with dizziness of vestibular origin often complain of episodic vertigo that
may include spinning or tilting and a sense of being off balance, whereas patients
 CASE 27: ORTHOSTATIC HYPOTENSION 211

with nonvestibular dizziness often complain of constant lightheadedness, a floating

sensation, a swimming sensation, or giddiness. Dizziness of vestibular origin is often
produced or exacerbated by rapid head movements and certain changes in position such
as rolling over in bed.
3. Symptoms associated with vestibular disorders include nausea, vomiting,
unsteadiness, tinnitus, hearing loss, impaired vision, and oscillopsia, whereas
nonvestibular dizziness is more likely to be associated with perspiration,
palpitations, paresthesias, syncope or presyncope, difficulty concentrating, and
malaise.
4. Symptoms of faintness and presyncope should suggest a nonvestibular cause for a
patient’s dizziness, such as postural hypotension, medication side effects,
intermittent hyperventilation associated with anxiety, hypoglycemia, anemia, and
hypothyroidism.
5. Vestibuloautonomic pathway may underlie the mechanism whereby vestibular
abnormalities cause malaise, nausea, and vomiting. These pathways are thought to
underlie the ability of vestibular activity to alter blood pressure and heart rate.
6. Patients with orthostatic hypotension become dizzy when they move from a
recumbent to an upright position. Blood pressure and heart rate should be measured
with the patient supine and after standing for 2 minutes. This allows differentiation
between transient symptoms due to a sluggish baroreceptor response (common in the
elderly) and true orthostatic hypotension. Sustained decrease in systolic BP of more than
20 mm Hg or diastolic BP of more than 10 mm Hg while standing is diagnostic of
orthostatic hypotension.
7. Orthostatic hypotension, which is a manifestation of abnormal blood pressure
regulation, has many different causes. The most common causes are hypovolemia
due to excessive use of diuretic agents or other medications, impaired autonomic reflex
mechanisms due to use of certain medications, multiple system atrophy, diabetic
neuropathy, other disorders associated with autonomic insufficiency, and peripheral
vascular insufficiency.

References

1. Cohen E, Grossman E, Sapoznikov B, Sulkes J, Kagan I, Garty M: Assessment of orthostatic

hypotension in the emergency room. Blood Press 15(5):263–267, 2006.
2. Bannister R: Treatment of progressive autonomic failure. In: Bannister R (ed). Autonomic
Failure: A Textbook of Clinical Disorders of the Autonomic Nervous System. New York:
Oxford University Press, 1983, p 323.
3. Smitt AA, Wieling W, Fumimura J, Deng JC, Opfer-Gehrking TL, Akarriou M, Karemaker
JM, Low PA: Use of lower abdominal compression to combat orthostatic hypotension in
patients with autonomic dysfunction. Clin Auton Res 14(3):167–175, 2004.
Case 28
Horizontal Semicircular
Canal Benign Paroxysmal
Positional Vertigo

History

A 50-year-old man complained of 3 weeks of positional dizziness. He noted symptoms of

brief vertigo that occurred only when rolling over in bed, either to the right or to the left.
Otherwise, the patient, who worked as a design engineer, had no symptoms. His medical
history was significant for hypertension, which was treated with a diuretic. Ten years
earlier, the patient had had 1 week of positional dizziness that resolved spontaneously. He
had no significant family history.
Question 1: Based on the patient’s history, what is the differential diagnosis?
Answer 1: This patient’s history is highly suggestive of benign paroxysmal positional
vertigo (see Cases 7, 23, 24, 25, 26, and 39). Although he may have another cause
of episodic vertigo, which has a broad differential diagnosis, benign paroxysmal
positional vertigo is most likely.1

Physical Examination

The patient’s general, neurologic, and otologic examinations were normal. On neurotologic
examination, no nystagmus was seen with infrared goggles when the patient was sitting.
Dix-Hallpike maneuvers were negative. However, when the patient was asked to move
from the supine to the lateral position or to turn his head to the right or left while his torso
was supine (roll maneuver), he became vertiginous for approximately 10 seconds and was
noted to have horizontal nystagmus that lasted as long as the vertigo. The nystagmus was
associated with nausea but no vomiting. The nystagmus was noted to be right-beating in the
right-lateral and head-right positions and left-beating in the head-left and left-\parlateral
positions. If the patient maintained a lateral or head-turned position, neither nystagmus nor

212
 CASE 28: HORIZONTAL CANAL BPPV 213

vertigo persisted after they had decayed. The vertigo and nystagmus were much more
intense with the right ear down.

Laboratory Testing

Videonystagmography: Ocular motor function was normal. There was no vestibular nystag-
mus when the patient was seated, and the caloric test was normal. On static positional testing,
however, the patient was noted to have 10 to 15 seconds of nystagmus that was right-beating
in the head-right and right-lateral positions and left-beating in the head-left and left-lateral
positions. The amplitude of the nystagmus was much higher with the right ear down.
Rotational testing was normal.
Posturography was normal.
Vestibular evoked myogenic potentials were normal.
Question 2: What is the significance of the time course and direction of the patient’s
positional nystagmus?
Answer 2: The patient has a paroxymsal rather than a persistent horizontal nystag-
mus. This time course suggests free-floating debris in the horizontal semicircular
canal rather than a mismatch of cupular and endolymphatic specific gravity (see
Case 52). The direction of the nystagmus is geotropic, that is, right-beating with the
right ear down and left-beating with the left ear down. This is consistent with
excitation of the down ear or inhibition of the up ear during positional testing.
Note that ageotropic horizontal nystagmus (see Case 52) which this patient does
not exhibit, also suggests a mismatch of cuplar and endolymphatic specific gravity
rather than free-float debris.

Diagnosis/Differential Diagnosis

Question 3: Based on the patient’s history, physical examination, and laboratory studies,
what is the diagnosis?
Answer 3: This patient is suffering from horizontal semicircular canal benign
paroxysmal positional vertigo (HCBPPV).2–5 This entity is thought to result
from free-floating debris in the horizontal semicircular canal endolymph in
much the same way that typical (posterior semicircular canal) benign paroxys-
mal positional vertigo results from debris in the posterior semicircular canal
endolymph. Interestingly, it is not uncommon to see HCBPPV occur transiently
as a sequela of a particle-repositioning maneuver for posterior semicircular canal
benign paroxysmal positional vertigo6 or spontaneously some time later after an
episode of posterior semicircular canal benign paroxysmal positional vertigo
resolves spontaneously.
Question 4: Because patients with HCBPPV experience vertigo and have geotropic
nystagmus in both lateral positions, how can this condition be lateralized to one ear?
Answer 4: Based on the presumed pathophysiology of this condition (Case 28: Figure 1),
the affected ear is determined by the lateral position that provokes the more intense
vertigo and nystagmus.
This patient was given the diagnosis of HCBPPV affecting the right ear.
214 VESTIBULAR DISORDERS

Case 28: Figure 1 Schematic drawing showing the presumed pathophysiology of horizontal
semicircular canal benign paroxysmal positional vertigo affecting the right ear. The right
horizontal semicircular canal is illustrated in three panels: left lateral position, supine
position, and right lateral position. Small arrows indicate movement of the debris within the
endolymph. Large arrows indicate the direction of cupula deviation. Movement of the head from
the supine position to the right lateral position causes movement of debris in an ampulopedal
direction, which produces excitation of the right horizontal semicircular canal and, thus, right-
beating horizontal nystagmus. Movement of the head from the supine position to the left
lateral position produces movement of debris in an ampulofugal direction, which produces
inhibition of the right horizontal semicircular canal ampulla and, thus, left-beating horizontal
nystagmus.
Source: With permission from Baloh RW, Jacobson K, Honrubia V. Horizontal semicircular canal variant of
benign paroxysmal vertigo. Neurology 43:2542–2549, 1993.4

Treatment/Management

Question 5: What is the treatment for patients with HCBPPV?

Answer 5: Analogous to the treatment for typical benign paroxysmal positional
vertigo, which affects the posterior semicircular canal, treatment for HCBPPV
also consists of a particle-repositioning maneuver.7,8 The patient is turned in the
appropriate manner to move the debris that is presumed to be floating in the
endolymph of the horizontal semicircular canal into the vestibule. This particle
repositioning is accomplished by rolling the patient slowly 270 degrees from the
supine position toward the unaffected ear, then to the prone position, then to
the side-down position with the affected ear down, then quickly back to the
seated position (see Case 28: Figure 2). 9 The maneuver should be performed
slowly.
Another treatment option for HCBPPV is the Gufoni maneuver.10 The
patient begins the maneuver in sitting, falling quickly with their head directly
to the noninvolved side with the neck in neutral and are asked to maintain the
position for 2 minutes. After 2 minutes, their head is quickly rotated in yaw 45
degrees toward the floor and they remain in this position for another 2
minutes. Then the patient is asked to slowly return to the seated position.
The advantage of the Gufoni maneuver is that it may be more comfortable for
the patient than the 270 degree roll maneuver.11 Still another treatment
option is to have the patient lie on their side with the involved ear up for
many hours.12,13
 CASE 28: HORIZONTAL CANAL BPPV 215

Case 28: Figure 2 Treatment of horizontal semicircular canal benign paroxysmal positional
vertigo affecting the right ear. Following establishment of the diagnosis, the patient is placed in
the supine position (A). Note that the free-floating otolith debris reaches the most dependent
position within the horizontal semicircular canal. Then, the patient is rotated toward the intact
ear (in this case, the left ear) by 90 degrees to reach the left lateral position (B). Note the
movement of the debris toward the vestibule. Then the patient is rotated another 90 degrees to
reach the prone position (C). Note the presumed position of the debris in the vestibule. The
patient is rotated a final 90 degrees to reach the right lateral position to complete the particle-
repositioning procedure (D). The patient is then quickly returned to the seated position (E).
Source: Adapted with permission from Nuti D et al: The management of horizontal-canal paroxysmal
positional vertigo. Acta Otolaryngol (Stockh) 118:455–460, 1998. 10

Summary

A 50-year-old male design engineer presented with 3 weeks of positional vertigo. Physical
examination disclosed a negative Dix-Hallpike maneuver, but paroxysmal vertigo and
nystagmus were elicited during static positional testing. Laboratory tests were negative
aside from paroxysmal nystagmus induced by assuming the head-right, head-left, right-lateral,
and left-lateral positions. The patient received the diagnosis of HCBPPV. Treatment
consisted of a special particle-repositioning maneuver comparable to that used for the
216 VESTIBULAR DISORDERS

treatment of typical posterior semicircular canal benign paroxysmal positional vertigo.

After this maneuver, the patient was asymptomatic.

Teaching Points

1 HCBPPV is a variant of typical benign positional vertigo. It is thought to result from

debris in the endolymph of the horizontal semicircular canal rather than in the posterior
semicircular canal, as occurs in typical benign positional vertigo.
2. The diagnosis of HCBPPV can be made by turning the patient’s head to the right
and to the left while the patient is supine. The patient will become vertiginous for 10 to
30 seconds, and a paroxysmal horizontal nystagmus will be observed for as long as the
vertigo persists. The nystagmus is right-beating in the head-right position and left-beating
in the head-left position. Patients with HCBPPV have vertigo and nystagmus in both head-
turned positions. However, when the affected ear is down, the vertigo and nystagmus that
are provoked are more intense than those experienced with the unaffected ear down.
3. Treatment for HCBPPV consists of a special particle-repositioning maneuver. The
patient is rolled 270 degrees from the supine position toward the unaffected ear, then to
the prone position, and then to the side-down position with the affected ear down, then
back to the supine position.

References
1. Moon SY, Kim JS, Kim BK, Kim JI, Lee H, Son SI, Kim KS, Rhee CK, Han GC, Lee WS:
Clinical characteristics of benign paroxysmal positional vertigo in Korea: A multicenter
study. J Korean Med Sc, 21(3):539–543, 2006.
2. McClure JA: Horizontal canal BPV. J Otolaryngol 14:30–35, 1985.
3. Pagnini P, Nuti D, Vannucchi P: Benign paroxysmal vertigo of the horizontal canal. ORL J
Otorhinolaryngol Relat Spec 51:161–170, 1989.
4. Baloh RW, Jacobson K, Honrubia V: Horizontal semicircular canal variant of benign
positional vertigo. Neurology 43:2542–2549, 1993.
5. De la Meilleure G, Dehaene I, Depondt M, Damman W, Crevits L, Vanhooren G: Benign
paroxysmal positional vertigo of the horizontal canal. J Neurol Neurosurg Psychiatry
60:68–71, 1996.
6. Herdman SJ, Tusa RJ: Complications of the canalith repositioning procedure. Arch
Otolaryngol Head Neck Surg 122(3):281–286, 1996.
7. Lempert T: Horizontal benign positional vertigo. Neurology 44:2213–2214, 1994.
8. Lempert T, Tiel-Wilck T: A positional maneuver for treatment of horizontal-canal benign
positional vertigo. Laryngoscope 106:476–478, 1996.
9. Escher A, Ruffieux C, Maire R: Efficacy of the barbecue manoeuvre in benign paroxysmal
vertigo of the horizontal canal. Eur Arch Otorhinolaryngol 264(10):1239–1241, 2007.
10. Gufoni M, Mastrosimone L, Di Nasso F: Repositioning maneuver in benign paroxysmal
vertigo of horizontal semicircular canal. Acta Otorhinolaryngol Ital 18(6):363–367, 1998.
PMID: 10388148.
11. Francesco R, Francesco D, Salvatore J, Gautham K, Roselia G, Ricccardo S. Management of
benign paroxysmal positonal vertigo of lateral semicircular canal by Gufoni’s manoeuvre. Am
J Otolaryngol, 30:106–111, 2009.
12. Nuti D, Agus G, Barbieri MT, Passali D: The management of horizontal-canal paroxysmal
positional vertigo. Acta Otolaryngol (Stockh) 118(4):455–460, 1998.
13. Vannucchi P, Giannoni B, Pagnini P: Treatment of horizontal semicircular canal benign
paroxysmal positional vertigo. J Vestib Res 7(1):1–6, 1997.
Case 29
Bilateral Meniere’s Disease

History

A 63-year-old man complained of vertigo and progressively worsening unsteadiness and

disequilibrium. The patient reported a 20-year history of unilateral Meniere’s disease but
indicated that his current complaints included both recurrent vertigo and symptoms that
were very different from recurrent vertigo. He noted that he had new gait instability with
veering to both the right and to the left, which was worse in the dark or while walking on
soft (compliant) or uneven surfaces. In addition to unsteadiness, the patient reported
difficulty with his vision, especially when attempting to focus on traffic signals or when
walking or when driving an automobile. He was unable to work in his usual occupation as
an electrician.
In addition to his balance complaints, the patient reported recent worsening of his
hearing. He had first noted episodic loss of hearing in his right ear approximately 20 years
ago at about the time when he first began having attacks vertigo. At first, hearing improved
between spells of vertigo but over time the loss of hearing became permanent. The patient’s
hearing seemed stable during the preceding 3 years. However, during the last few months,
he had noticed increasing difficulty with communication, especially in understanding
speech in the presence of background noise. He found that he had become increasingly
reliant on lip reading.

Question 1: Based on the patient’s history, what are the diagnostic considerations?
Answer 1: This patient has a history of Meniere’s disease affecting the right ear. His
recent history suggests a return of episodic vertigo that may be based upon an
exacerbation of his right-sided vestibular abnormality. Alternatively, the patient
may be suffering from an additional disorder affecting the left vestibular system or
less likely, the central nervous system. The patient’s complaint of abnormal vision
suggests possible oscillopsia caused by bilateral vestibular loss (see Case 4).
Additionally, the patient’s complaint of worsening hearing and difficulty with
communication suggests possible bilateral cochlear involvement. Taken together,
these aspects of the patient’s history suggest bilateral otologic disease, probably
bilateral Meniere’s disease. In patients with bilateral Meniere’s disease, a thorough
search for autoimmune disease of the ear, Cogan’s syndrome, allergic, leutic, and
metabolic causes of ear disease should be undertaken.

217
218 VESTIBULAR DISORDERS

Physical Examination

Neurologic examination revealed full extraocular movements without nystagmus. The

remainder of the neurologic examination was normal except that the patient’s gait had a
wide base. Romberg’s test was negative. Otoscopic examination was normal. Decreased
hearing ability to finger rub was noted in both ears. On neurotologic examination, the
patient had a low amplitude right-beating nystagmus behind infrared goggles. On head
thrust testing, refixation saccades were noted with brisk head movements both to the right
and the left. During ophthalmoscopy, a reduced vestibulo-ocular reflex was noted. The
dynamic visual acuity test was abnormal.1 The patient was unable to stand on a compliant
foam surface with eyes closed without falling. Gait was unsteady.
Question 2: based upon the additional information from physical examination, what is the
patient’s likely diagnosis?
Answer 2: The patient’s physical examination suggests bilateral vestibular loss (see
Case 4) as well as an ongoing vestibulo-ocular reflex asymmetry. Specifically, the
combination of oscillopsia and bilaterally abnormal head thrust testing and abnor-
mal vestibulo-ocular reflex testing using ophthalmoscopy and inability to stand on
a compliant phone surface with eyes closed suggests bilateral vestibular loss. The
low amplitude spontaneous vestibular nystagmus suggests a vestibulo-ocular
asymmetry. Thus, the patient’s physical examination lends further support to a
diagnosis of bilateral ear disease.

Laboratory Testing

Videonystagmography: ocular motor testing was normal aside from a low amplitude right-
beating spontaneous vestibular nystagmus. There was a direction fixed right-beating static
positional nystagmus. Caloric testing revealed absent responses to bithermal stimulation.
In the right ear, there was no response to ice water irrigation with a low amplitude right-
beating nystagmus unaffected by thermal stimulation. In the left ear, there was a small but
definite response to ice water irrigation.
Rotational testing revealed severely reduced responses with a low amplitude right-beating
nystagmus seen during testing. Responses were evident during sinusoidal stimulation at
frequencies above 0.5 Hz and following constant velocity rotation at 90 degrees per second.
Vestibular evoked myogenic potential testing showed reduced but present responses in
both ears.
Posturography indicated to excessive sway on conditions 5 and 6, that is, a vestibular
loss pattern.
Audiometric testing indicated a bilateral asymmetric sensorineural hearing loss (Case
29: Figure 1). Electrocochleography of the left ear indicated an elevated summating
potential to action potential ratio consistent with endolymphatic hydrops. Reliable poten-
tials could not be obtained for the right ear.
An MRI scan of the brain was normal.
Question 3: Based upon the patient’s history, physical examination, and laboratory testing,
what is the most likely diagnosis?
Answer 3: The patient’s laboratory testing confirms bilateral otologic disease with
severely reduced vestibular function bilaterally. Testing also confirms the mild
vestibular ocular reflex asymmetry. Audiometric testing showing new hearing loss
 CASE 29: BILATERAL MENIERE’S DISEASE 219

Case 29: Figure 1 Audiogram.

on the left side suggests active Meniere’s disease in the left ear. Bilateral Meniere’s
disease remains the most likely diagnosis. The patient’s history suggests that the
long-standing right-sided otologic problem has been stable with a recent involve-
ment of the left ear consistent with Meniere’s disease.
Question 4: Why is this patient experiencing both episodic vertigo and oscillopsia and
disequilibrium?
Answer 4: The episodes of vertigo are likely due to fluctuating peripheral vestibular
function caused by active Meniere’s disease. In this case, the right ear with estab-
lished Meniere’s disease, the left ear with recent change in hearing, or both ears
could be involved. To resolve this uncertainty, clinicians should first consider the ear
showing fluctuations in auditory function or other otologic symptoms such as aural
fullness or tinnitus, as the offending ear.
It is notable that despite the fact that the patient has markedly reduced or absent
vestibular responsiveness in the right ear and from long-standing Meniere’s disease,
his new episodic loss of vestibular function in the left ear is provoking symptoms
similar to those seen in individuals with unilateral vestibular involvement with an
intact contralateral vestibular system. This phenomenon, known as Becterew’s
phenomenon, is characterized by similar behavioral manifestations in persons
with acute unilateral peripheral vestibular disease with normal function contralat-
erally as that seen in persons with acute unilateral peripheral vestibular disease who
have compensated for a previous contralateral vestibular deficit.
This patient’s symptoms of oscillopsia and disequilibrium suggest that he is
manifesting symptoms and signs of bilateral vestibular loss (see Case 4) super-
imposed upon an episodic vestibular asymmetry.
220 VESTIBULAR DISORDERS

Question 5: How often does Meniere’s disease occur in both ears?

Answer 5: Estimates in the literature of the incidence of bilateral Meniere’s disease
range between 5% and 50%. The wide range of incidence rates largely reflects the
criteria used to determine whether Meniere’s disease was present in the opposite
ear and the duration of observation. Several studies utilizing electrophysiologic
criteria suggest asymptomatic endolymphatic hydrops can be present in the con-
tralateral ear in 10% to 27% of patients with unilateral Meniere’s disease.2,3
Retrospective chart reviews of busy otologic practices show 11% to 19% of patients
presented with clinical evidence of bilateral involvement such as contralateral
hearing loss and/or tinnitus suggesting endolymphatic hydrops.4,5 In one study
an additional 14% showed bilateral involvement over a 5-year follow-up period for
a total prevalence of 25% of patients with bilateral involvement. A reasonable
estimate is that 30% of patients with unilateral disease will develop symptoms of
Meniere’s disease in the opposite ear at some time in their life.6,7 Bilateral Meniere’s
disease may have a genetic basis.8
Question 6: Can bilateral Meniere’s disease occur many years following the onset of
unilateral Meniere’s disease?
Answer 6: Yes. As exemplified by the patient presented in this case, bilateral
Meniere’s disease can occur many years following the onset of unilateral
Meniere’s disease. However, as noted in Question 5, asymptomatic and early
auditory manifestations of bilateral disease are often present at initial evaluation
of active unilateral disease, and progression to bilateral disease is often evident
within 5 years.

Treatment

Question 7: What treatments are appropriate for a patient with bilateral Meniere’s
disease?
Answer 7: In general, conservative treatment options should be considered and
ablative treatments avoided. As with patients with unilateral Meniere’s disease,
patients with bilateral Meniere’s disease should be treated with a low sodium diet
and a diuretic. If this fails, oral immunosuppressive therapy for 4 to 6 weeks and
intratympanic steroid injections of the active ear can be tried. One or both ears can
be safely treated with the Meniett micro-pressure device. Endolymphatic sac
decompression and shunting can be used when one of the ears can be clearly
identified as the active offending ear. Vestibular suppressant medications should be
used only intermittently for symptomatic relief of active vertigo. Ablative surgical
procedures should be avoided if possible.
Another treatment consideration for patients with disabling vertigo due to
bilateral Meniere’s disease that is nonresponsive to conservative measures is intra-
muscular streptomycin therapy. Intramuscularly streptomycin is a means of redu-
cing vestibular function bilaterally and thus can be used to treat vertigo caused by
simultaneously active Meniere’s disease in both ears, vertigo in a patient with
bilateral Meniere’s disease when the active ear can not be determined, Meniere’s
disease in an only hearing ear, and in the second ear when the first ear has been
previously treated with an ablative procedure. Intramuscular streptomycin, like
ablative surgical procedures, should be considered only in patients with disabling
episodic vertigo who have not responded to conservative measures and must be
 CASE 29: BILATERAL MENIERE’S DISEASE 221

given in a controlled manner to produce a subtotal vestibular ablation with the dose
titrated to control episodes of acute vertigo while stopping short of a complete
bilateral loss of vestibular function.9

Follow-Up

The patient was treated with a low sodium diet and a diuretic. Symptoms persisted without
change, and 2 months later the patient was treated with oral Prednisone starting at 60 mg/
day for 2 weeks followed by an extended taper to 20 mg/every other day for 6 weeks. He
was also given dietary counseling to help with controlling his salt intake. Additional testing
for possible environmental and food allergies was requested.
The episodes of vertigo improved but gait instability and hearing loss persisted. He was
referred for a hearing aid evaluation and to vestibular rehabilitation for gait training and fall
prevention counseling.

Summary

Bilateral Meniere’s disease was diagnosed in a patient with previously diagnosed, long-
standing unilateral Meniere’s disease. Symptoms of acute vertigo and persistent gait
instability and oscillopsia were present that suggested a combination of an acute recurrent
unilateral vestibular disorder and bilateral vestibular loss. Audiological and vestibular
function testing confirmed involvement of both ears. Intensive medical management was
begun that reduced the severity of episodic vertigo, but bilateral deficits of both hearing
and vestibular function persisted.

Teaching Points

1. Approximately 30% of patients with unilateral disease will develop symptoms of

Meniere’s disease in the opposite ear at some time in their life.
2. Bilateral Meniere’s disease will manifest almost always within 5 years of the initial
presentation of unilateral disease, but can also occur many years later.
3. Medical therapy is the first line of treatment. Ablative procedures should be
avoided if possible.
4. Intramuscularly streptomycin is an effective treatment for disabling vertigo in a
patient with bilateral Meniere’s disease refractory to conservative treatment.
Intramuscular streptomycin must be given in a controlled manner to prevent total
vestibular ablation.
5. Becterew’s phenomenon refers to the occurrence of symptoms of acute vestibular
imbalance in persons with acute unilateral peripheral vestibular disease who have
compensated for a previous contralateral vestibular deficit.

References
1. Longridge NS, Mallison AI: A discussion of the Dynamic Illegible ‘‘E’’ Test: A new method
of screening for aminoglycoside vestibulotoxicity. Otolaryngol Head Neck Surg
92(6):671–677, 1984.
2. Conlon BJ, Gibson WP: Meniere’s disease: The incidence of hydrops in the contralateral
symptomatic ear. Laryngoscope 109:1800–1802, 1999.
222 VESTIBULAR DISORDERS

3. Lin MY, Timmer FC, Oriel BS, Zhou G, Guinan JJ, Kujawa SG, Hermann BS, Merchant SN,
Rauch SD: Vestibular evoked myogenic potentials (VEMP) can detect asymptomatic saccular
hydrops. Laryngoscope 166(6):987–992, 2006.
4. House JW, Doherty JK, Fisher LM, Derebery MJ, Berliner KI: Meniere’s disease: Prevalence
of contralateral ear involvement. Otol Neurotol 27(3):355–361, 2006.
5. Vrabec JT, Simon LM, Coker NJ: Survery of Meniere’s disease in a subspecialty referral
practice. Otolaryngol Head Neck Surg 137(2):213–217, 2007.
6. Wladislavosky-Waserman P, Facer GW, Mokri B, Kurland LT: Meniere’s disease: A 30 year
epidemiology and clinical study in Rochester, MN, 1951–1980. Laryngoscope 94:1098–1102,
1984.
7. Yazawa Y, Kitahara M: Bilateral endolymphatic hydrops in Meniere’s disease: Review of
temporal bone autopsies. Ann Otol Rhinol Laryngol 99:524–528, 1990.
8. Lopez-Escamez JA, Vilchez JR, Soto-Varela A, Santos-Perez S, Perez-Garrigues H, Aran I,
Lopez-Nevot MA: HLA-DRB1*1101 allele may be associated with bilateral Meniere’s
disease in southern European population. Otol Neurotol 28(7):89–895, 2007.
9. Langman AW, Kemink JL, Graham MD: Titration streptomycin therapy for bilateral
Meniere’s disease. Ann Otol Rhinol Laryngol 99:923–926, 1990.
Case 30
Multiple Sclerosis

History

A 40-year-old woman presented with a chief complaint of blurred vision, lightheadedness,

and imbalance. There was no complaint of hearing loss or tinnitus. The patient had a
medical history of multiple sclerosis with intermittent exacerbations. She had suffered
from optic neuritis on several occasions. Additionally, she had suffered intermittent
exacerbations characterized by weakness, incoordination, and urinary dysfunction. The
patient recovered to a large extent from each of these episodes and was able to continue her
work as a licensed practical nurse. One week before evaluation, the patient awoke with
vertigo. She noticed a sense of disorientation worsened by head movement and had severe
imbalance while attempting to walk. There was no change in any of her other neurologic
functions. The patient’s symptoms had decreased slightly during the week before evalua-
tion. The family history was noncontributory.
Question 1: Based on the history, what is the likely cause of the patient’s symptoms?
Answer 1: This patient’s symptoms of vertigo and imbalance suggest a vestibular
system abnormality. Multiple sclerosis could be an underlying cause of the patient’s
condition if there is a lesion in central vestibular structures. Additionally, she could
be suffering from a peripheral vestibular abnormality independent of her multiple
sclerosis. In this case, the patient’s central nervous system abnormalities might be
interfering with compensation for a peripheral vestibular deficit (see Case 3).

Physical Examination

The patient’s general examination was normal. Eye movement examination revealed a left-
beating nystagmus on left gaze. There was no evidence of internuclear ophthalmoplegia or
gaze paresis and no vertical nystagmus. The patient had normal strength and sensation.
Coordination testing revealed an abnormal finger-to-nose test response in the left upper
extremity. Otherwise, there was no abnormality of coordination. Deep tendon reflexes
were brisk and symmetric. Plantar responses were flexor bilaterally. Gait was mildly
ataxic, with a negative Romberg’s test. Otologic examination was normal. Neurotologic
examination revealed a left-beating nystagmus in the primary position using infrared
goggles. The patient was unable to stand on a compliant foam surface without assistance
and fell toward the right.

223
224 VESTIBULAR DISORDERS

Question 2: Based on the history and physical examination, what is this patient’s likely
diagnosis?
Answer 2: The physical examination suggests the presence of a vestibular abnorm-
ality. The patient also has signs of central nervous system involvement, with an
abnormal finger-to-nose test response on the left and gaze-evoked nystagmus on
leftward gaze, which might have been the result of an accentuated vestibular
nystagmus. The ataxic gait could be a result of either a vestibular system or a
cerebellar system abnormality or both. Thus, the patient has evidence of combined
peripheral and central vestibular abnormalities.

Laboratory Testing

Videonystagmography: A spontaneous left-beating nystagmus was recorded. There was a

direction-fixed left-beating positional nystagmus. Caloric responses revealed a right
reduced vestibular response of 50%.
Rotational testing revealed increased phase lead with a normal amplitude of responses.
A left directional preponderance was noted.
Posturography indicated excessive sway on conditions 3, 5, and 6, that is, a combined
vestibular deficit and visual dependence pattern (see Chapter 4).
Vestibular evoked myogenic potentials were markedly reduced on the right.
Audiometric testing showed normal hearing in the left ear. The right ear showed a mild
to moderate high-frequency sensorineural hearing loss. Word recognition scores were
normal bilaterally (Case 30: Figure 1).

Case 30: Figure 1 Audiogram.

 CASE 30: MULTIPLE SCLEROSIS 225

Case 30: Figure 2 Axial magnetic resonance image showing the high signal intensity typical of
multiple sclerosis in the region of the eighth nerve root entry zone (arrow). A line drawing of the major
anatomic structures of the brain stem is shown for comparison. T = 5temporal lobe; Ch = cochlea; N VII &
VIII = cranial nerves 7 and 8; HSC = horizontal semicircular canal; Vest5labyrinthine vestibule;
SO = superior olive; VII = facial nucleus; V(sn) = trigeminal nucleus and spinal-trigeminal tract;
ICP = inferior cerebellar peduncle; 4th = fourth ventricle; VN = vestibular nuclei.
Source: With permission from Furman JM et al: Eighth nerve signs in a case of multiple sclerosis. Am J Otolaryngol
10:376–381, 1989.3

An MRI scan of the brain revealed a vestibular root entry-zone lesion on the right
(Case 30: Figure 2). The scan also indicated numerous periventricular white matter
hyperintensities on weighted images.

Diagnosis/Differential Diagnosis

Question 3: Based on the information from the laboratory tests in addition to the informa-
tion from the history and physical examination, what is this patient’s likely diagnosis?
Answer 3: This patient has evidence of vestibular system involvement based on the
history, physical examination, and vestibular laboratory testing. The MRI scan
indicates a vestibular root entry-zone lesion. Thus, the patient is likely to have
symptoms of dizziness and disequilibrium due to multiple sclerosis, which can
account for both the peripheral and central vestibular symptoms and signs.
Question 4: Should this patient’s eighth nerve root entry-zone lesion be considered a
peripheral or central vestibular abnormality?
Answer 4: A root entry-zone lesion should be considered a peripheral vestibular
abnormality on the basis of function because damage is limited to afferent vestib-
ular activity. Structurally, of course, a root entry-zone lesion, because it is intrapar-
enchymal, is a central nervous system abnormality and thus could be labeled a
central vestibular lesion. Moreover, patients with root entry-zone lesions due to
multiple sclerosis often have a much more prolonged recovery period than patients
with peripheral vestibular ailments. This prolongation of recovery probably results
from lesions other than that at the root entry zone.
226 VESTIBULAR DISORDERS

Case 30: Table 1 Comparison of Posterior-Inferior Cerebellar Artery (PICA) and Anterior-Inferior
Cerebellar Artery (AICA) Syndromes

Seen in Both PICA and Typically Seen Only Typically Seen Only
AICA Sydromes in PICA Sydrome in AICA Syndrome

Symptoms Vertigo, lateropulsion, Hoarseness Tinnitus, hearing

unusual visual illusions, loss, and facial
facial numbness, limb weakness
numbness,
disequilibrium, dysphagia,
and incoordination
Signs Vestibular nystagmus, Saccadic lateropulsion, Hearing loss, facial
decreased facial sensation i.e., saccades that are too weakness, and gaze
ipsilaterally, sensory loss large when looking in palsy
to pain and temperature one direction horizontally,
contralaterally, Horner’s and too small when
syndrome, ipsilateral limb looking in the other
ataxia, and gait ataxia direction, skew deviation,
and vocal cord paralysis
Laboratory Abnormal imaging, Saccadic lateropulsion Caloric reduction
Abnormalities spontaneous nystagmus, ipsilaterally
and decreased hearing
Pathophysiology Damage of fifth nerve Damage of nucleus Damage of inner ear,
nucleus, spinothalamic ambiguus and dorsal eighth cranial nerve,
tract, and vestibular motor nucleus seventh cranial
nuclei nerve, seventh and
eighth cranial nerve
root-entry zones,
sixth nerve nucleus,
flocculus, and
middle cerebellar
peduncle

This patient was given the diagnosis of demyelination of the vestibular nerve root
entry zone caused by multiple sclerosis.
Question 5: What are the common vestibular and ocular motor symptoms and signs
associated with demyelinating disease?
Answer 5: Demyelinating disease, most notably multiple sclerosis, can present with the
acute onset of vertigo, as in this case. Statistically, about 5% of patients with multiple
sclerosis suffer from vertigo as their first neurologic symptom,1 but most suffer from
vertigo or disequilibrium at some time during the disease.2 Patients with root entry-
zone lesions may exhibit asymmetric vestibular function, including spontaneous nys-
tagmus, a unilateral reduced vestibular response on caloric testing, a directional pre-
ponderance on caloric and/or rotational testing, and abnormal platform
posturography.3,4 These patients often suffer from blurred vision. Patients with multi-
ple sclerosis whose lesions do not affect the root entry zone may also have evidence of
vestibulo-ocular, vestibulospinal, or balance abnormalities as a result of brainstem and
cerebellar lesions that affect central vestibular structures, notably the vestibular nuclei.5
Symptoms may be exacerbated by optic neuritis and posterior column disease, which
may affect visual and somatosensory inputs important for balance.
 CASE 30: MULTIPLE SCLEROSIS 227

Typical eye movement abnormalities associated with multiple sclerosis include

internuclear ophthalmoplegia with dissociated nystagmus, gaze-evoked nystagmus,
vertical nystagmus (see Case 34), positional nystagmus, abnormal accuracy of sac-
cades, and, occasionally, pendular nystagmus (see Case 50) (see Grenman2 for a
review).

Treatment/Management

The patient was referred to a vestibular rehabilitation therapy program6,7 and given a short
(2-week) trial of meclizine. Her dizziness and lightheadedness gradually resolved and her
balance slowly improved, but she still had a wide-based gait.

Summary

A 40-year-old woman with a history of multiple sclerosis complained of a vertiginous

episode 1 week before evaluation, followed by persistent disequilibrium. Physical exam-
ination and vestibular laboratory testing suggested a combined peripheral and central
vestibular abnormality. MRI disclosed a vestibular root entry-zone lesion, as well as
numerous small areas of increased signal intensity. The patient was thought to have a
vestibular system problem due to multiple sclerosis with both peripheral and central
features. Vestibular-suppressant medication was prescribed for a period of 2 weeks, during
which the patient’s dizziness decreased. A course of vestibular rehabilitation therapy
produced a small but definite improvement in balance.

Teaching Points

1. Vertigo and imbalance in patients with multiple sclerosis may indicate a lesion in
central vestibular structures. A peripheral vestibular abnormality independent of
multiple sclerosis should also be considered.
2. A root entry-zone lesion, because it is intraparenchymal, is a central nervous
system abnormality and, strictly speaking, is a central vestibular lesion.
However, a root entry-zone lesion often behaves like a peripheral vestibular
abnormality because damage is limited to afferent vestibular activity.
3. Both peripheral and central vestibular symptoms and signs can be seen in patients
with multiple sclerosis. A lesion that includes the vestibular root entry zone in addition
to other brainstem structures interrupts vestibular afferents in the lateral brainstem,
causing abnormalities indistinguishable from those due to an end-organ lesion.
4. Prolonged recovery is seen in patients with root entry-zone lesions caused by
multiple sclerosis. This protracted recovery probably results from lesions other than
those at the root entry zone that impair compensation.
5. Multiple sclerosis can present with vestibular and ocular motor symptoms and
signs. About 5% of patients with multiple sclerosis suffer from vertigo as their first
neurologic symptom.
6. Eye movement abnormalities associated with multiple sclerosis include
internuclear ophthalmoplegia, gaze-evoked nystagmus, vertical nystagmus,
saccadic dysmetria, and pendular nystagmus.
228 VESTIBULAR DISORDERS

References
1. McAlpine D: Symptoms and signs, brain-stem multiple sclerosis. In: McAlpine D, Lumsden
CE, Acheson ED (eds). Multiple Sclerosis: A Reappraisal. London: Churchill Livingstone,
1972, pp 164–196.
2. Grenman R: Involvement of the audiovestibular system in multiple sclerosis. An
otoneurologic and audiologic study. Acta Otolaryngol 420(Suppl):1–95, 1985.
3. Furman JM, Durrant JD, Hirsch WL: Eighth nerve signs in a case of multiple sclerosis.
Am J Otolaryngol 10:376–381, 1989.
4. Williams NP, Roland PS, Yellin W: Vestibular evaluation in patients with early multiple
sclerosis. Am J Otol 18:93–100, 1997.
5. Bronstein AM, Rudge P: Vestibular involvement in spasmodic torticollis. J Neurol Neurosurg
Psychiatry 49:290–295, 1986.
6. Kasser SL, Rose DJ, Clark S: Balance training for adults with multiple sclerosis: Multiple case
studies. Neurol Rep 23(1):5–12, 1999.
7. Cattaneo D, Jonsdottir J, Zocchi M, Regola A: Effects of balance exercises on people with
multiple sclerosis: A pilot study. Clin Rehabil 21(9):771–781, 2007.
Case 31
Convergence Spasm

History

A 35-year-old woman presented with dizziness that began following head trauma 6 months
prior to evaluation. The patient slipped on ice and fell on her right arm and shoulder, after
which her head struck the ground. She did not lose consciousness but did develop a small
subdural hematoma. The patient described her dizziness as a sense of lightheadedness and
disequilibrium without vertigo. She did not notice symptoms when turning in bed or
looking up. The patient noted neck discomfort without localized pain, and there was no
association between the neck discomfort and her dizziness. There was no complaint of
hearing loss or tinnitus. The patient’s medical history was significant for migraine and a
single panic attack several weeks prior to evaluation. Within the last 6 months, the patient
was treated unsuccessfully with meclizine, which she discontinued. She was using ibupro-
fen on an as-needed basis.
Question 1: Based upon the patient’s history, what are the possible diagnoses?
Answer 1: This patient’s dizziness complaints are nonspecific. The temporal relation-
ship with head trauma suggests the possibility of a labyrinthine concussion. A
brainstem concussion seems unlikely since the head trauma appears mild and did
not cause loss of consciousness. The patient’s history does not suggest benign
paroxysmal positional vertigo (see Cases 7, 23, 24, 25, 26, 28, 39) despite its
frequent onset following head trauma. Also, the patient’s history does not suggest
cervicogenic dizziness (Case 58). Post-traumatic endolymphatic hydrops (Case 9,
12, 20, 24, 42) also does not seem likely given the absence of hearing loss and
tinnitus.

Physical Examination

Neurologic examination revealed apparent bilateral sixth nerve palsies. Specifically, when
the patient attempted to gaze to the right or left, she was unable to abduct the right or the left
eye. It was noted that her pupils constricted with attempted lateral gaze. With monocular
viewing, the patient was able to abduct her eyes normally. The remainder of the neurologic
examination was normal. Otologic examination was normal. Neurotologic examination
revealed unusual eye movements during a search for spontaneous nystagmus using infrared
video goggles. Specifically, the patient was noted to have intermittent convergence with

229
230 VESTIBULAR DISORDERS

associated pupillary constriction. During these episodes the patient complained of an odd
sensation of eyestrain. The head thrust test, positional test, and stability on a foam pad all
were normal.
Question 2: What is the significance of the patient’s abnormal physical examination?
Answer 2: The pupillary constriction during gaze testing suggests that the patient’s
apparent bilateral sixth nerve palsies are a result of the superimposition of conver-
gence and lateral gaze. That is, the patient’s physical examination suggests con-
vergence spasm, an abnormality in which there is excessive and inappropriate
convergence.1–6 The spontaneous convergence seen with infrared video goggles
also suggests convergence spasm which can be seen following head trauma.7 The
patient had no evidence for a vestibular system abnormality.
Question 3: How might convergence spasm lead to complaints of dizziness?
Answer 3: A patient with convergence spasm will experience abnormal vision
intermittently. Visual difficulties may result from abnormal focusing, excessive
accommodation, or ocular misalignment, that is, strabismus, during convergence
spasms. Such visual difficulties can be interpreted by the patient as dizziness.

Laboratory Testing

Videonystagmography: Ocular motor, positional, and caloric tests were normal.

Rotational testing was normal.
Posturography revealed increased sway in all sway conditions in a nonspecific pattern.
An MRI scan of the brain was normal.

Diagnosis/Differential Diagnosis

Question 4: What are the causes of convergence spasm? What is the likely cause of
convergence spasm in this patient?
Answer 4: Convergence spasm has been seen with numerous disorders, which are
listed in Case 31: Table 1. This patient has no evidence of any of the disorders listed
other than idiopathic convergence spasm.

Case 31: Table 1 Causes of Convergence Spasm

Thalamic hemorrhage
Pineal tumor
Encephalitis
Wernicke-Korsakoff syndrome
Vertebrobasilar insufficiency
Chiari malformation
Multiple sclerosis
Metabolic encephalopathy
Phenytoin intoxication
Idiopathic convergence spasm
Head trauma
 CASE 31: CONVERGENCE SPASM 231

Question 5: Are there other abnormalities of vergence eye movements that can present with
dizziness?
Answer 5: Another type of abnormality of vergence eye movements is convergence
insufficiency. Convergence insufficiency is a somewhat controversial disorder char-
acterized by decreased positive fusional vergence at near.8–11 Convergence insuffi-
ciency can be associated with dizziness presumably because of blurred or double
vision when looking at nearby objects. These visual abnormalities can be inter-
preted as dizziness by some patients.
This patient was given the diagnosis of convergence spasm of uncertain etiology
following minor head trauma.

Treatment

Question 6: What treatment strategies are appropriate for a patient with convergence
spasm of uncertain etiology?
Answer 6: Referral of such patients to an ophthalmologist or neuro-ophthalmologist
is appropriate. For patients with one of the well-defined etiologies in Case 31:
Table 1, specific treatment of the underlying condition should be instituted. For
patients with functional convergence spasm, cycloplegic eye drops, correction of
refractive error or the addition of minus lenses, and occlusion of the medial third of
the visual field of each eye and botox12,13 have been advocated.

Follow-Up

The patient was referred to a neuro-ophthalmologist, who confirmed the diagnosis of

convergence spasm. The patient did not respond to cycloplegic eye drops. At a follow-up
evaluation 3 months later, the patient had a normal examination and was nearly symptom-
free.

Summary

A 35-year-old woman presented with dizziness that began following head trauma 6 months
prior to evaluation. There was no loss of consciousness, but a small subdural hematoma
was identified. Dizziness symptoms included lightheadedness and disequilibrium. Vertigo
was absent. Physical examination was normal except for apparent bilateral sixth nerve
palsies. Pupillary constriction during attempted lateral gaze and spontaneous convergence
behind infrared video goggles suggested convergence spasm as the etiology for the
patient’s dizziness. Cycloplegic eye drops were not helpful.

Teaching Points

1. Patients with convergence spasm, that is, frequent inappropriate or excessive

convergence, may experience abnormal vision intermittently. Visual
difficulties may result from abnormal focusing, excessive accommodation, or ocular
misalignment, that is, strabismus, during convergence spasms. Such visual difficulties
can be interpreted by the patient as dizziness.
232 VESTIBULAR DISORDERS

2. Convergence spasm is associated with numerous disorders, which are listed in

Case 31: Table 1. Idiopathic convergence spasm may occur following minor head
trauma.
3. For patients with a well-defined etiology for convergence spasm, specific treatment
of the underlying condition should be instituted. For patients with convergence
spasm, cycloplegic eye drops, correction of refractive error or the addition of minus
lenses, and occlusion of the medial third of the visual field of each eye have been tried
with limited success.
4. Another type of abnormality of vergence eye movements, convergence
insufficiency, is a somewhat controversial disorder characterized by decreased
positive fusional vergence at near. It can be associated with dizziness presumably
because of visual abnormalities such as blurry vision and possibly even double vision
when looking at nearby objects.

References

1. Cogan DG, Freese CG: Spasm of the near reflex. Arch Ophthalmol 54:752–759, 1955.
2. Griffin JF, Wray SH, Anderson DP: Misdiagnosis of spasm of the near reflex. Neurology
26:1018–1020, 1976.
3. Nirankari VS, Hameroff SB: Spasm of the near reflex. Ann Ophthalmol 12:1050–1051, 1980.
4. Sarkies NJC, Sanders MD: Convergence spasm. Trans Ophthalmol 104:782–786, 1985.
5. Rabinowitz Dagi LR, Chrousos GA, Cogan DC: Spasm of the near reflex associated with
organic disease. Am J Ophthalmol 103:582–585, 1987.
6. Goldstein JH, Schneekloth BB: Spasm of the near reflex: A spectrum of anomalies. Surv
Ophthalmol 40:269–278, 1996.
7. Chan RV, Trobe JD: Spasm of accommodation associated with closed head trauma.
J Neuroophthalmol 22(1):15–17, 2002.
8. Daum KM: Characteristics of convergence insufficiency. Am J Optom Physiol Optics
65(6):426–438, 1988.
9. Cohen M, Groswasser Z, Barchadski R, Appel A: Convergence insufficiency in brain-injured
patients. Brain Injury 3(2):187–191, 1989.
10. Lepore FE: Disorders of ocular motility following head trauma. Arch Neurol 52:924–926,
1995.
11. Birnbaum MH, Soden R, Cohen AH: Efficacy of vision therapy for convergence insufficiency
in an adult male population. J Am Optom Assoc 70:225–232, 1999.
12. Schwartze GM, McHenry LC Jr, Proctor RC: Convergence spasm-treatment by amytal
interview: A case report. J Clin Neuroophthalmol 3:123–125, 1983.
13. Kaczmarek BB, Dawson E, Lee JP: Convergence spasm treated with botulinum toxin.
Strabismus 17(1):49–51, 2009.
Case 32
Superior Semicircular Canal
Dehiscence Syndrome—
Tullio’s Phenomenon

History

A 30-year-old woman complained of disequilibrium and intermittent dizziness. Symptoms

began several years prior to evaluation but recently became noticeably worse following a
ski vacation. The dizziness seemed to be associated with loud sounds, including her own
voice, especially when they approached from her right. Along with her dizziness, the
patient noticed difficulty with vision because of an apparent movement of visual objects.
Another type of dizziness occurred with coughing, sneezing, and straining at stool. With
this latter dizziness, the patient did not notice any alterations in her vision. She did not
complain of hearing loss, tinnitus, or ear fullness. Her medical history was negative.
She had used meclizine for her symptoms without relief and was currently using no
medications.
Question 1: Based on the patient’s history, what are the diagnostic considerations? What is
the significance of the patient’s sensitivity to loud sounds? What is the significance of her
sensitivity to coughing, sneezing, and bowel movements?
Answer 1: This patient’s history suggests a vestibular abnormality based on the
combination of dizziness and visual disturbance. The most prominent feature of
the patient’s history is the elicitation of dizziness both with loud sounds and with
activities that increase intrathoracic pressure. Moreover, the patient experienced
abnormal vision in response to loud sounds, which suggests the presence of sound-
induced abnormal eye movements.
Dizziness in response to sound has been termed the Tullio phenomenon. The
Tullio phenomenon has been associated with Meniere’s syndrome, congenital ear
anomalies, infectious etiologies such as syphilis, chronic ear pathology, trauma,
perilymphatic fistula, and fenestration surgery.1 The patient’s sensitivity to changes
in intrathoracic pressure is of uncertain cause but can be associated with the same
etiologies that cause the Tullio phenomenon. The patient’s history does not suggest
Meniere’s syndrome or an infectious etiology. She had not suffered trauma or
undergone ear surgery.

233
234 VESTIBULAR DISORDERS

Physical Examination

Neurologic examination was normal, with the exception of difficulty performing tandem
walking. Neurotologic examination revealed no spontaneous nystagmus, no post-
headshake nystagmus, a normal head thrust test, a negative Dix-Hallpike test, and
increased sway without falling when asked to stand on a compliant foam surface with
the eyes closed. With tragal stimulation on the right, Valsalva maneuver, or pneumatic
otoscopy on the right, the patient experienced her typical pressure-induced dizziness.
Simultaneous observation of the patient’s eye movements using infrared goggles revealed
abnormal eye movements during pneumatic otoscopy but no abnormal eye movements
during tragal stimulation or Valsalva maneuver. The abnormal eye movement observed
was a vertical-torsional eye deviation without nystagmus. Cranial vibration also induced a
vertical-torsional nystagmus.
Question 2: Based on the patient’s physical examination, what are the likely diagnoses?
What is the Hennebert symptom and the Hennebert sign? What is the significance of the
patient’s positive Hennebert symptom and sign?
Answer 2: The patient’s physical examination suggests a right-sided peripheral
vestibular ailment that has produced pressure sensitivity and sound sensitivity. A
perilymphatic fistula is the most likely diagnosis, although the other conditions
noted above must be considered. The vertical-torsional eye movement induced by
pneumatic otoscopy suggests involvement of one of the vertical semicircular canals
on the right. This patient had both a positive Hennebert symptom and a positive
Hennebert sign, that is, pressure-induced dizziness and pressure-induced eye
movements, respectively. Hennebert’s symptom and sign originally were believed
to be pathognomonic for syphilitic osteitis of the temporal bone. Hennebert’s sign
can be positive in Meniere’s disease, where it is thought to be due to vestibular
fibrosis causing the otolith organs to contact the undersurface of the stapes,2 in the
presence of a perilymphatic fistula and can occur after stapedectomy.

Laboratory Testing

Videonystagmography revealed no spontaneous or gaze-evoked nystagmus, normal posi-

tional testing, and normal caloric responses.
Rotational testing revealed a directional preponderance.
Posturography reveal increased postural sway in a nonspecific pattern.
VEMPs revealed high amplitude responses at a reduced threshold. The VEMP on the
left was normal.
Audiometric testing revealed a mild low-frequency sensorineural hearing loss in the
right ear.
Question 3: Based on the additional information available from laboratory testing, what is
the likely diagnosis? Should additional testing be considered?
Answer 3: Laboratory testing suggests that the horizontal semicircular canals
respond normally. However, the directional preponderance on rotational testing
suggests an ongoing vestibulo-ocular imbalance. Vestibular evoked myogenic
potentials suggest an overly sensitive sacculocollic reflex on the right.3
Audiometric testing suggests a right-sided abnormality consistent with the
 CASE 32: SUPERIOR SEMICIRCULAR CANAL DEHISCENCE SYNDROME 235

patient’s complaints of dizziness when exposed to loud noises on the right. To

better define the anatomy of the right labyrinth, the patient should undergo a
specialized CT scan of the temporal bones.

Additional Laboratory Testing

A CT scan of the temporal bones that was optimized for visualizing the superior semi-
circular canal revealed a dehiscence of the right superior semicircular canal.4 Case 32:
Figure 1 illustrates diagrammatically the finding seen on the CT scan. The left side was
normal.
Question 4: What is dehiscence of the superior semicircular canal?
Answer 4: Dehiscence of the superior semicircular canal is a recently described finding
in which the bone overlying the rostral aspect of the superior semicircular canal is thin
or absent.5 This is a variant of a semicircular canal fistula (Case 32: Figure 2).
Question 5: What is the mechanism for the signs and symptoms seen with dehiscence of the
superior semicircular canal?
Answer 5: The signs and symptoms seen in patients with dehiscence of the superior
semicircular canal probably relate to the transmission of pressure from the external
auditory canal into the vestibular labyrinth.6,7 This patient’s complaints of visual
motion when exposed to loud sounds and her abnormal eye movements during
pneumatic otoscopy probably relate to inappropriate stimulation of the vestibular
hair cells of the right superior semicircular canal in response to sound or pressure.
The exact mechanism of nystagmus provoked by cranial vibration is not known.
Vibration may cause abnormal movement of the dura at the site of the bony defect
of the semicircular canal. Alternatively, vibration may excite the superior canal
directly resulting in nystagmus in the plane of the affected superior canal.8

Case 32: Figure 1 Diagrammatic illustration of dehiscence of the right superior semicircular
canal.
Source: With permission from Smullen JL, et al: Superior semicircular canal dehiscence: A new cause of
vertigo. J La State Med Soc 151:397–400, 1999. 7
236 VESTIBULAR DISORDERS

Case 32: Figure 2 Histologic section of the temporal bone showing bony dehiscence of the
superior semicircular canal. mf = middle fossa floor; sc = semicircular canal; sps = superior
petrosal sinus.
Source: With permission from Carey JP et al: Dehiscence or thinning of the bone overlying the superior
semicircular canal in a temporal bone study. Arch Otolaryngol Head Neck Surg 126:137–147, 2000.8

Question 6: What other signs and symptoms can be seen in patients with dehiscence of the
superior semicircular canal?
Answer 6: Clinicians should be aware that dehiscence of the superior semicircular
canal is a great otologic mimicker9 because these patients can present with symp-
toms suggestive of eustachian tube dysfunction (ear fullness and autophony),
Meniere’s disease (recurrent vertigo and ear fullness, and abnormal electrocholeo-
graphy10), and otosclerosis (conductive hearing loss11).

Treatment

Question 7: What are the treatment options for a patient with dehiscence of the superior
semicircular canal?
Answer 7: Treatment options for patients with dehiscence of the superior semicir-
cular canal include observation, use of a pressure ventilation tube, an ear plug in
noisy places, or surgical repair. Many patients are relieved to receive a diagnosis that
explains their symptoms, and because the symptoms are rarely disabling, they may
 CASE 32: SUPERIOR SEMICIRCULAR CANAL DEHISCENCE SYNDROME 237

choose to do nothing further. Surgical repair can be offered to those troubled by the
symptoms.
The patient requested surgical intervention. The repair was performed via a
middle fossa craniotomy. The dehiscent segment was repaired by creating a rigid
seal of the canal using bone pâte and covering the area with a chip of cortical bone
to separate the canal from the dura of the temporal lobe.

Follow-Up

Three months following surgery, the patient reported no further episodes of sound sensi-
tivity or symptoms associated with increased intrathoracic pressure. However, she con-
tinued to suffer from mild disequilibrium.

Summary

A 30-year-old woman complained of disequilibrium and intermittent dizziness associated

with loud sounds, coughing, sneezing, and straining at stool. The patient’s physical
examination suggested a right-sided peripheral vestibular ailment that produced pressure
sensitivity and sound sensitivity consistent with a perilymphatic fistula. A CT scan of the
temporal bones revealed a dehiscence of the right superior semicircular canal. Surgical
repair was performed to re-create a rigid seal of the semicircular canal. Sound and pressure
sensitivity remitted, but mild disequilibrium persisted.

Teaching Points

1. Dizziness in response to sound is termed the Tullio phenomenon. The Tullio

phenomenon has been associated with Meniere’s syndrome, congenital ear anomalies,
syphilitic osteitis of the temporal bone, chronic ear pathology, trauma, perilymphatic
fistula, and stapes surgery.
2. Pressure-induced dizziness is termed Hennebert’s symptom, and pressure-induced
eye movements is termed Hennebert’s sign. Hennebert’s symptom and sign are
nonspecific indicators of a peripheral vestibular disorder. They can be positive in
leutic involvement of the inner ear; in Meniere’s disease, where it is thought to be
due to vestibular fibrosis causing the saccule to contact the undersurface of the stapes; in
the presence of a perilymphatic fistula; and can occur after stapedectomy.
3. Dehiscence of the superior semicircular canal is to a recently described finding in
which the bone overlying the rostral aspect of the superior semicircular canal is
thin or absent.
4. Nonvestibular otologic signs and symptoms including ear fullness, autophony, and
conductive hearing loss are frequently associated with dehiscence of the superior
semicircular canal. These symptoms can mimic several other otologic conditions
including eustachian tube dysfunction, Meniere’s disease, and otosclerosis.
5. Treatment options for patients with dehiscence of the superior semicircular canal
include observation, placement of a pressure ventilation tube, use of an ear plug in
noisy places, and surgical repair.
238 VESTIBULAR DISORDERS

References
1. Watson SRD, Halmagyi M, Colebatch JG: Vestibular hypersensitivity to sound (Tullio
phenomenon). Neurology 54:722–728, 2000.
2. Nadol JB: Positive ‘‘fistula sign’’ with an intact tympanic membrane. Arch Otolaryngol
100:273–278, 1974.
3. Brantberg K, Verrecchia L: Testing vestibular-evoked myogenic potentials with 90dB clicks
is effective in the diagnosis of superior canal dehiscence syndrome. Audiol Neurootol,
14(1):54–58, 2009.
4. Crane BT, Minor LB, Carey JP: Three-dimensional computed tomography of superior canal
dehiscence syndrome. Otol Neurotol 29(5):699–705, 2008.
5. Carey JP, Minor LB, Nager GT: Dehiscence or thinning of the bone overlying the superior
semicircular canal in a temporal bone study. Arch Otolaryngol Head Neck Surg 126:137–147,
2000.
6. Minor LB, Solomon D, Zinreich J, Zee DS: Sound- and/or pressure-induced vertigo due to
bone dehiscence of the superior semicircular canal. Arch Otolaryngol Head Neck Surg
124(3):249–258, 1998.
7. Hirvonen TP, Carey JP, Liang CJ, Minor LB: Superior canal dehiscence: mechanisms of
pressure sensitivity in a chinchilla model. Arch Otolaryngol Head Neck Surg 127:1331–1336,
2001.
8. White JA, Hughes GB, Ruggieri PN: Vibration-induced nystagmus as an office procedure for
the diagnosis of superior semicircular canal dehiscence. Otol Neurotol 28(7):911–916, 2007.
9. Zhou G, Gopen Q, Poe DS: Clinical and diagnostic characterization of canal dehiscence
syndrome: a great otologic mimicker. Otol Neurotol 28(7):920–926, 2007.
10. Arts HA, Adams ME, Telian SA, El-Kashlan H, Kileny PR: Reversible electrocochleographic
abnormalities in superior canal dehiscence. Otol Neurotol 30(1):79–86, 2009.
11. Merchant SN, Rosowski JJ: Conductive hearing loss caused by third-window lesions of the
inner ear. Otol Neurotol 2008.
Case 33
Vertebrobasilar Insufficiency

History

A 70-year-old man presented with episodic dizziness. The patient’s symptoms had been
particularly troublesome during the last 6 weeks. He described spontaneous episodes
occurring about twice a week, characterized by the acute onset of vertigo and a tendency
to fall to the right, lasting for seconds to a few minutes. There were no clear precipitating
factors such as changes in head position or standing after sitting or lying down. The patient
had no complaints of hearing loss or tinnitus. His history was significant for hypertension
and peptic ulcer disease. Current medications included an angiotensin converting enzyme
inhibitor and an H2 blocking agent.
Question 1: What are the diagnostic considerations in this case, and what further historic
information would be helpful in establishing a diagnosis?
Answer 1: This patient’s symptoms are suggestive of an episodic dysfunction of
peripheral vestibular function such as Meniere’s disease (see Cases 9, 12, 20, 24, 42)
or benign paroxysmal positional vertigo (see Cases 7, 23, 24, 25, 26, 28, 29). The
absence of symptoms related to changes in head position makes benign paroxys-
mal positional vertigo less likely. The absence of associated otologic symptoms such
as hearing loss or tinnitus makes Meniere’s disease less likely. Orthostatic hypoten-
sion also is unlikely. The duration of symptoms, the patient’s age, and a history of
hypertension all suggest the possibility of vertebrobasilar insufficiency, although a
structural abnormality of the posterior fossa is another diagnostic possibility. A
thorough history regarding associated neurologic complaints would be helpful in
establishing a diagnosis. A family history would also be helpful.

Additional History

Upon careful questioning, the patient noted that with several of his vertiginous episodes he
had experienced circumoral paresthesias and, on one occasion, double vision. His family
related that during some of the patient’s episodes his speech was often difficult to under-
stand, and he walked ‘‘like he was drunk.’’ The patient had no family history of neurologic
or otologic disease.

239
240 VESTIBULAR DISORDERS

Case 33: Table 1 Initial Symptoms of Vertebrobasilar

Insufficiency

Symptoms Percentage

Vertigo 48
Visual hallucinations 10
Drop attacks or weakness 10
Visceral sensations 8
Visual field defects 6
Diplopia 5
Headaches 3
Other 8
Source: Adapted with permission from Baloh RW, Honrubia V: Clinical
Neurophysiology of the Vestibular System, ed 2. Philadelphia: FA Davis, 1990, p 221.9

Case 33: Table 2 Symptoms Associated with Vertebrobasilar Insufficiency

Symptoms Percentage

Visual dysfunction 69
Drop attacks 33
Unsteadiness, incoordination 21
Extremity weakness 21
Confusion 17
Headache 14
Hearing loss 14
Loss of consciousness 10
Extremity numbness 10
Dysarthria 10
Tinnitus 10
Perioral numbness 5
Source: Adapted with permission from Grad A, Baloh RW: Vertigo of vascular origin. Arch Neurol
46:281–284, 1989.5

Question 2: What are the characteristic features of vertebrobasilar insufficiency, and what
information would be helpful in establishing this as the patient’s diagnosis?
Answer 2: Although vertigo alone is rarely a symptom of vertebrobasilar insuffi-
ciency,1–3 especially if the vertigo is chronic,4 Grad and Baloh5 have indicated that
vertigo alone can be the presenting sign of vertebrobasilar insufficiency. Case 33:
Table 1 presents the initial symptoms of vertebrobasilar insufficiency. Note that
vertigo appears at the top of this list. Patients with vertebrobasilar insufficiency can
experience vertigo in isolation for up to 1.5 years.5 Case 33: Table 2 lists associated
symptoms in patients with vertebrobasilar insufficiency.
A complete physical examination and brain and cerebro-vascular imaging are
likely to add additional diagnostic information to this case.

Physical Examination

The patient had entirely normal general, neurologic, and otologic examinations, with the
exception of several ‘‘soft’’ neurologic signs, including a very mild left pronator drift and
 CASE 33: VERTEBROBASILAR INSUFFICIENCY 241

an equivocal Babinski sign on the left. There was no orthostatic hypotension. There were
no carotid bruits. The patient had a slightly widened base to his gait. Neurotologic
examination, including Dix-Hallpike maneuvers, was normal, with the exception of difficulty
standing on a compliant foam surface with the eyes closed.

Laboratory Testing

Videonystagmography: Ocular motor, positional, and caloric tests were normal.

The rotational test was normal.
Audiometric testing revealed bilateral high-frequency sensorineural hearing loss.
An MRI scan of the head revealed an old infarction of the right frontal lobe, a right
internal carotid artery occlusion, and bilateral white matter hyperintensities in the periven-
tricular white matter. There were no obvious abnormalities in the brainstem or cerebellum.
An extracranial MRA revealed the right internal carotid artery occlusion. An intracranial
MRA revealed ectatic right vetebral artery and narrowing of the basilar artery.

Diagnosis/Differential Diagnosis

Question 3: Based on the history, physical examination, and laboratory studies, what is this
patient’s most likely diagnosis and why?
Answer 3: The patient’s episodes are not typical of benign paroxysmal positional
vertigo, and Dix-Hallpike maneuvers were negative. There was no acute syndrome
to suggest vestibular neuritis. A vestibular-only form of Meniere’s disease (see Case 9)
is possible, but the patient’s episodes are brief compared to typical episodes of
endolymphatic hydrops, there is no associated hearing loss or tinnitus, and some of
the patient’s episodes are associated with neurologic deficits. Migraine-associated
dizziness (see Cases 8, 20, 22, 23) is also a diagnostic possibility, but there is no prior
history of headache or family history of migraine. Thus, the patient is probably
suffering from vertebrobasilar insufficiency, considering the duration of episodes,
the combination of symptoms that characterize his attacks, his history of hyperten-
sion, and evidence of cerebrovascular disease on brain imaging. The abnormal MRA
further increases the likelihood of this diagnosis.
The patient was given a diagnosis of vertebrobasilar insufficiency, that is, an
abnormality of blood flow in the vertebral arteries, the basilar artery or their
branches.

Treatment/Management

The patient was treated with an antiplatelet agent. The frequency of his vertiginous
episodes decreased markedly, but episodes of dizziness still occurred occasionally.
Question 4: What is the vascular supply of the vestibular system? What is the pathophysiologic
basis for this patient’s vertiginous episodes?
Answer 4: Case 33: Figure 1A is a schematic diagram of the vertebrobasilar system.
Note that the posterior-inferior cerebellar artery, which arises from the vertebral
artery, supplies the vestibular nuclei, while the anterior-inferior cerebellar artery,
which arises from the basilar artery, supplies the vestibulocerebellum and gives rise
242 VESTIBULAR DISORDERS

(a) (b)

Case 33: Figure 1 Blood supply to the brainstem and cerebellum. (A) Schematic drawing of the
vertebrobasilar arterial tree. PCA = posterior cerebral artery; SCA = superior cerebellar
artery; AICA = anterior inferior cerebellar artery; IAA = internal auditory canal artery; PICA =
posterior inferior cerebellar artery; VA = vertebral artery; BA = basilar artery. (B) Drawing
highlighting each of the three neurovascular complexes of the posterior fossa. The upper
complex is related to the superior cerebellar artery; the middle complex is related to the anterior
inferior cerebellar artery; the lower complex is related to the posterior inferior cerebellar artery.
(A) Source: Modified with permission from Oas JG, Baloh RW: Vertigo and the anterior inferior cerebellar
artery syndrome. Neurology 42:2274–2279, 1992. 7 (B) Source: With permission from Rhoton AL:
Microsurgical anatomy of posterior fossa cranial nerves. In: Barrow DL (ed). Surgery of the Cranial Nerves
of the Posterior Fossa. Park Ridge: American Associations of Neurological Surgeons, 1993, p 2.8

to the internal auditory artery (labyrinthine artery), which, in turn, gives rise to the
anterior vestibular artery.
Ischemia in the vertebrobasilar arterial system can cause vestibular symptoms
due to peripheral vestibular dysfunction, central vestibular dysfunction, or both
(Case 33: Figure 1B). Because the vestibular nuclei are supplied by the posterior-
inferior cerebellar artery, a brief interruption of the vertebral artery or of the posterior-
inferior cerebellar artery itself can cause transient symptoms similar to those
experienced in Wallenberg’s syndrome (see Case 37). Because the anterior-inferior
cerebellar artery supplies the labyrinth and the vestibulocerebellum, a brief inter-
ruption of this artery can also lead to episodic vestibular symptoms (see also Case
38). Baloh6 has hypothesized that the vertigo seen with vertebrobasilar insuffi-
ciency is probably related to labyrinthine ischemia. For much of the blood supply
to the vestibular system, the arteries are end-arterial (see Chapter 1), and therefore
the opportunity for collateral circulation is limited. This is especially true for the
blood supply to the peripheral vestibular system, as well as for the small perforating
arteries that supply the brainstem. It should be noted that there is much variability
in the vertebrobasilar system, which may lead to variability in presentation.

Summary

A 70-year-old man presented with episodic vertigo lasting for minutes and occasionally
associated with double vision, slurred speech, and ataxic gait. The patient had a history of
hypertension. Examination revealed ‘‘soft’’ neurologic signs, and brain imaging revealed
 CASE 33: VERTEBROBASILAR INSUFFICIENCY 243

evidence of cerebrovascular disease. The patient was given the diagnosis of vertebrobasilar
insufficiency and treated with an antiplatelet agent.

Teaching Points

1. The blood supply of the vestibular system is derived from the basilar artery. It
includes (1) the posterior-inferior cerebellar artery, which arises from the vertebral
artery and supplies the vestibular nuclei; (2) the anterior-inferior cerebellar artery,
which arises from the basilar artery and supplies the vestibulocerebellum; and (3) the
internal auditory artery, which arises from the anterior-inferior cerebellar artery and
gives rise to the anterior vestibular artery, which supplies the vestibular apparatus.
2. Ischemia in the vertebrobasilar artery system can cause vestibular symptoms due
to peripheral vestibular dysfunction, central vestibular dysfunction, or both. For
much of the blood supply to the vestibular system, the arteries are end-arterial and
therefore the opportunity for collateral circulation is limited, especially for the blood
supply to the peripheral vestibular system.
3. A diagnosis of vertebrobasilar insufficiency should be reserved for patients who
have clearly defined episodes of transient neurologic symptoms and signs that can be
localized to the posterior circulation. Vertebrobasilar insufficiency can present with
many different neurologic symptoms. Even if vertigo is not the presenting complaint
of vertebrobasilar insufficiency, eventually most patients with vertebrobasilar
insufficiency experience vertigo on one or more occasions.
4. Isolated vertigo, especially if chronic, is rarely a symptom of vertebrobasilar
insufficiency. However, vertigo associated with definitive neurologic symptoms,
especially in a patient with risk factors for cerebrovascular disease, should lead to a
consideration of vertebrobasilar insufficiency.

References
1. Ferbert A, Bruckmann H, Drummen R: Clinical features of proven basilar artery occlusion.
Stroke 21(8):1135–1142, 1990.
2. Estol C, Caplan LR, Pressin MS: Isolated vertigo: An uncommon manifestation of
vertebrobasilar ischaemia. Cerebrovasc Dis 6(Suppl 2):161, 1996.
3. Gomez CR, Cruz-Flores S, Malkoff MD, Sauer CM, Burch CM: Isolated vertigo as a
manifestation of vertebrobasilar ischemia. Neurology 47(1):94–97, 1996.
4. Fisher CM: Vertigo in cerebrovascular disease. Arch Otolaryngol 85:529–534, 1967.
5. Grad A, Baloh RW: Vertigo of vascular origin. Arch Neurol 46:281–284, 1989.
6. Baloh RW: Otological aspects of cerebrovascular disease. In: Toole JF (ed). Handbook of
Clinical Neurology, Vol 11: Vascular Diseases, Part III. New York: Elsevier Science, 1989,
pp 129–135.
7. Oas JG, Baloh RW: Vertigo and the anterior inferior cerebellar artery syndrome. Neurology
42: 2274–2279, 1992.
8. Rhoton AL: Microsurgical anatomy of posterior fossa cranial nerves. In: Barrow DL (ed).
Surgery of the Cranial Nerves of the Posterior Fossa. Park Ridge IL: American Association of
Neurological Surgeons, 1993, pp 1–103.
9. Baloh RW, Honrubia V: Clinical Neurophysiology of the Vestibular System, ed 2.
Philadelphia: FA Davis, 1990.
Case 34
Chiari Malformation

History

A 19-year-old female college student complained of constant dizziness and disequilibrium

for several years and a recent problem reading school work. The patient noted that she had
gait instability, with veering to both the right and the left. There was no true vertigo. Rather,
she experienced lightheadedness and disequilibrium, especially when tipping her head
back, even while seated. The patient was not particularly bothered by rapid head move-
ments and had no complaints of hearing loss or tinnitus. There was no significant medical
history. The family history was noncontributory.
Question 1: Based on the patient’s history, what are the diagnostic considerations?
Answer 1: This patient’s history is extremely nonspecific but does suggest a balance
system disorder. The symptoms cannot be definitively localized to either the central
or peripheral vestibular system. However, the absence of vertigo and the absence of
symptoms with rapid head movements suggest a central rather than a peripheral
vestibular system abnormality. The worsening of the patient’s symptoms when
tipping her head back suggests the possibility of a posterior fossa abnormality
such as a posterior (vertebrobasilar) circulation abnormality (see Case 33) or a
cervical abnormality (see Case 58).

Physical Examination

Neurologic examination revealed gaze-evoked nystagmus on left gaze, right gaze, and
upward gaze. Oblique down and lateral gaze both to the right and to the left revealed an
oblique-torsional (downbeating) nystagmus (Case 34: Figure 1). The patient also had
saccadic overshoot dysmetria when looking both to the right and to the left and abnormal
ocular pursuit with ‘‘catch-up’’ saccades. The remainder of the patient’s cranial nerve
examination was normal. Strength and sensation were normal. The coordination test was
normal. The patient had a widened base of gait. Romberg’s test was negative. Otologic
examination was normal. On neurotologic examination, she had no nystagmus in the
primary position, but with infrared goggles she demonstrated a spontaneous right-beating
nystagmus. The patient had difficulty standing on a compliant foam surface. There was no
pastpointing.

244
 CASE 34: CHIARI MALFORMATION 245

Case 34: Figure 1 Downbeating nystagmus. Shown are the direction and magnitude of
nystagmus in each of the nine cardinal positions of gaze. Note that the nystagmus is
oblique-torsional on downgaze and lateral gaze and that it is abolished by upgaze. Although it is
common for patients with downbeating nystagmus to have nystagmus in only downgaze and
lateral gaze, others have nystagmus that persists even with upward gaze.
With permission from Furman, JM: Nystagmus and the vestibular system. In Podos, SM, and Yanoff, M
(eds). Textbook of Ophthalmology. New York: Gower Medical, 1993.7

Question 2: Based on the physical examination, what is the most likely localization of this
patient’s lesion, and what are the likely diagnostic possibilities?
Answer 2: The patient’s downbeating nystagmus is suggestive of a craniocervical
junction abnormality. In combination with the gaze-evoked nystagmus, saccadic
dysmetria, and abnormal ocular pursuit, the patient appears to have a lesion of the
caudal midline cerebellum. Diagnostic considerations include a Chiari malforma-
tion, that is, caudally positioned cerebellar tonsils, a mass lesion, such as a foramen
magnum meningioma, or demyelinating disease. Given the gradual worsening of
symptoms and the patient’s relatively benign history, less likely etiologies include
an infectious process such as a viral or postviral syndrome, inflammatory disease,
and olivocerebellar degeneration syndrome.

Laboratory Testing

An MRI scan of the brain revealed a Chiari malformation with the cerebellar tonsils
approximately 5 mm below the foramen magnum and an obliterated ambient cistern
(Case 34: Figure 2).
Question 3: What is the role, if any, of vestibular laboratory testing in patients with Chiari
malformation? Should vestibular laboratory testing be ordered for this patient?
Answer 3: Although vestibular laboratory testing is not required to confirm the
diagnosis of Chiari malformation, it may be helpful in planning management, for
example, whether to request a neurosurgical consultation, and in following the
patient’s progress after posterior fossa decompression surgery if this procedure is
246 VESTIBULAR DISORDERS

Case 34: Figure 2 Chiari malformation. Sagittal T2-weighted image through the
cranio-cervical junction shows the cerebellar tonsils (solid arrow) extending far below the
foramen magnum (dashed line). The medulla is compressed.
With permission from Aminoff MJ (ed): Neurology and General Medicine, ed 4. Philadelphia: Churchill
Livingston [Elsevier], 2008. 8

performed. Vestibular laboratory testing provides a quantitative assessment of the

extent of a patient’s vestibular system abnormalities, including documentation of
any vestibular nystagmus suspected on physical examination. Moreover, some
patients with Chiari malformation manifest peripheral vestibular signs such as a
caloric reduction. Such information may aid management.
Despite the fact that vestibular laboratory testing may have confirmed some of
the abnormalities seen on physical examination, this patient’s Chiari malformation
is already thought to be symptomatic on the basis of the clinical evaluation, thereby
justifying a referral to a neurosurgeon. Thus, vestibular laboratory testing was not
obtained.
Question 4: What is the pathophysiologic basis for this patient’s nystagmus?
Answer 4: This patient had three types of nystagmus: (1) gaze-evoked nystagmus,
(2) downbeating nystagmus, and (3) spontaneous vestibular nystagmus. It is
important to note that, by definition, gaze-evoked nystagmus is left-beating on
left lateral gaze, right-beating on right lateral gaze, and upbeating on upward gaze.
Gaze-evoked nystagmus is typically conjugate, that is, both eyes move equally.
Nystagmus that beats down, even when seen only with downgaze, is considered
downbeating nystagmus, not gaze-evoked nystagmus elicited by downgaze.
Gaze-evoked nystagmus is thought to be a result of poor gaze holding caused by
an abnormal neural integrator,1 that is, a central nervous system circuit that converts
(integrates in the mathematical sense) an eye velocity command to an eye position
signal. The mechanism of gaze-evoked nystagmus is as follows: the viscoelastic
restoring forces of the globe tend to bring the eye toward the primary, that is, the
straight-ahead position. These forces are strongest when the eye is deviated away
from the primary position. In order to keep the eye on a target placed away from the
 CASE 34: CHIARI MALFORMATION 247

primary position, a tonic level of neural activity is required to overcome these

restoring forces. This required tonic level of activity during gaze away from the
primary position declines more quickly than normal in patients with abnormalities
of the neural integrator. With this decline of tonic activity, the eye gradually drifts
back toward the primary position. This slow drift of the eyes during attempted gaze
deviation is interrupted by quick (saccadic) eye movements that bring the eyes back
toward the target, away from the primary position. This alternation of slow drift (as
a result of a slowly declining tonic drive to the eye muscles) and rapid repositioning
movements constitutes gaze-evoked nystagmus. Because the rapid repositioning
movements are always in the direction of gaze, gaze-evoked nystagmus, by defini-
tion, always beats in the same direction as that of the gaze that evoked it.
There are multiple causes of gaze-evoked nystagmus. The most common causes are
the effect of drugs such as anticonvulsants and structural abnormalities in the posterior
fossa, especially those affecting the cerebellum. The precise location of the gaze-
holding mechanism (i.e., the neural integrator) is unknown, but the nucleus prepositus
hypoglossi, which is located in the medulla oblongata near the hypoglossal (twelfth
cranial nerve) nucleus, is a likely candidate for horizintal gaze holding.2 However, the
integrity of the neural integrator probably also depends on the cerebellum because
cerebellar lesions are frequently associated with gaze-evoked nystagmus.
Downbeating nystagmus is, by definition, a nystagmus wherein the quick compo-
nent is down or obliquely down and lateral (Case 34: Figure 1). Often, with oblique
downbeating nystagmus on down and lateral gaze, there is a torsional component,
with the upper pole of the eye beating in the direction of lateral gaze. Downbeating
nystagmus is thought to be caused by an imbalance of up versus down tonic drive to
the eyes. This up–down imbalance may be a result of unequal central vestibular path-
ways so that there is a stronger tonic drive to move the eyes up rather than down,3
resulting in a slow drift up and resetting quick movements down. An alternative
hypothesis is that downbeating nystagmus is caused by a vertical ocular pursuit
asymmetry so that the eyes drift up.4 In any case, the slow drifts up are interrupted
by quick resets down, leading to downbeating nystagmus. Downbeating nystagmus is
most often seen with lesions of the craniocervical junction and can also be seen as a
result of medication (see Case 47).
This patient’s spontaneous vestibular nystagmus is likely to be caused by a central
vestibular imbalance arising from an impairment of vestibular nuclear structures. As
discussed in Chapter 1, spontaneous vestibular nystagmus usually results from a
peripheral vestibular lesion. However, as in Case 37, medullary lesions involving the
vestibular nuclei can also result in tonic vestibular imbalance and cause spontaneous
vestibular nystagmus on a central basis. The fact that this patient’s spontaneous
primary position nystagmus was seen only with a loss of fixation suggests that her
fixational abilities allowed her to suppress the vestibular nystagmus. This ability to
suppress vestibular nystagmus is somewhat surprising because the patient demon-
strated impairment of ocular pursuit, which is considered to be very important for
visual–vestibular interaction. In some patients, however, there can be a discrepancy
between pursuit and fixation suppression of the vestibulo-ocular reflex.5

Diagnosis/Differential Diagnosis

This patient had a symptomatic Chiari malformation with associated ocular motor abnorm-
alities and imbalance.
248 VESTIBULAR DISORDERS

Treatment/Management

Based on the pathophysiology of a reduced posterior fossa volume,6 this patient was treated
with a suboccipital craniectomy and decompression of her Chiari malformation. Following
this treatment the patient was symptomatically much improved, with resolution of her
spontaneous vestibular nystagmus. Abnormal ocular pursuit, gaze-evoked nystagmus, and
downbeating nystagmus persisted.

Summary

A 19-year-old woman with a complaint of several years of dizziness and disequilibrium

had signs of a posterior fossa abnormality. An MRI scan disclosed a Chiari malformation.
The patient was treated with a suboccipital craniectomy and decompression. Symptoms of
dizziness and disequilibrium were markedly reduced. The spontaneous vestibular nystag-
mus disappeared, but gaze-evoked and downbeating nystagmus persisted.

Teaching Points

1. In downbeating nystagmus, the quick component is down or obliquely down on

downgaze and torsional on down-lateral gaze. Downbeating nystagmus is thought to
be caused by an imbalance of up versus down tonic drive to the eyes.
2. Downbeating nystagmus localizes the lesion to the craniocervical junction. Causes
include (1) Chiari malformation, (2) a mass lesion such as a foramen magnum
meningioma, or (3) demyelinating disease. Less likely causes include (4) an
infectious process such as a viral or postviral syndrome, (5) inflammatory disease,
and (6) an olivocerebellar degeneration syndrome.
3. Gaze-evoked nystagmus is a nystagmus that is left-beating on left lateral gaze, right-
beating on right lateral gaze, and upbeating on upward gaze. Gaze-evoked nystagmus is
typically conjugate. Nystagmus that beats down, even when seen only with downgaze, is
considered downbeating nystagmus, not gaze-evoked nystagmus. Gaze-evoked nystagmus
is thought to result from impaired gaze holding arising from an abnormal neural integrator, a
central nervous system circuit that converts (integrates in the mathematical sense) an eye
velocity command into an eye position signal. The most common causes of gaze-evoked
nystagmus are the effect of drugs such as anticonvulsants and structural abnormalities in the
posterior fossa, especially those affecting the cerebellum.

References

1. Leigh RJ, Zee DS (eds.): The Neurology of Eye Movements, ed 4. New York: Oxford
University Press, 2006.
2. Cannon SC, Robinson DA: The final common integrator is in the prepositus and vestibular
nuclei. In: Keller EL, Zee DS (eds). Adaptive Processes in Visual and Oculomotor Systems.
Oxford: Pergamon Press, 1986, pp 307–312.
3. Baloh RW, Spooner JW: Downbeat nystagmus: A type of central vestibular nystagmus.
Neurology 31:304–310, 1981.
4. Zee DS, Friendlich AL, Robinson DA: The mechanism of downbeat nystagmus. Arch Neurol
30:227–237, 1974.
 CASE 34: CHIARI MALFORMATION 249

5. Chambers B, Gresty M: The relationship between disordered pursuit and vestibulo-ocular

reflex suppression. J Neurol Neurosurg Psychiatry 46:61–66, 1983.
6. Trigylidas T, Baronia B, Vassilyadi M, Ventureyra EC: Posterior fossa dimension and volume
estimates in pediatric patients with Chiari I malformations. Childs Nervous System,
24(3):329–336, 2008.
7. Furman JM: Nystagmus and the vestibular system. In: Podos SM, Yanoff M (eds). Textbook of
Ophthalmology. New York: Gower Medical, 1993, pp 9.1–9.7.
8. Weber PC, Cass SP: Neurotologic manifestations of Chiari 1 malformation. Otolaryngol Head
Neck Surg 109:853–860, 1993.
Case 35
Orthostatic Tremor

History

A 70-year-old man presented with the complaint of unsteadiness while standing. The
patient’s symptoms had been present for the past 7 years and were gradually worsening.
He complained that after standing for 2 to 3 minutes, he felt very unsteady and fatigued and
needed to lean against something for support. He did not complain of dizziness. He was
asymptomatic when sitting or walking. There was no positional dizziness. His past medical
history was significant for bilateral hearing loss and arthritis. His surgical history included
resection of a colon cancer and prostate surgery. Medications included a cholesterol-
lowering agent. He did not consume alcohol. He had no complaints of double vision,
numbness, weakness, confusion, or difficulty with speech.
Question 1: What are the diagnostic considerations for this patient?
Answer 1: The patient’s history does not suggest a vestibular disorder because of the
absence of dizziness and gait instability. Rather, the patient’s symptoms suggest a
central nervous system abnormality affecting the postural control system. The
complaint of difficulty standing but not walking is quite unusual for both vestibular
disorders and central nervous system abnormalities that affect motor control such
as Parkinson’s disease.

Physical Examination

Neurologic examination revealed a palpable tremor in the lower extremities while the patient
was standing. This tremor was noted only after the patient had been standing for 1 to 2
minutes. No upper extremity tremor was seen at rest, with action, or with attention. The
remainder of the neurologic examination was normal, with the exception of mildly impaired
tandem gait. Otologic examination was normal. Neurotologic examination was normal.
Question 2: Based on the additional information from the physical examination, what are
the possible diagnoses?
Answer 2: The patient’s physical examination revealed an orthostatic tremor.1–3
There were no signs suggesting a vestibular system abnormality. The typical symptoms
and signs of orthostatic tremor are listed in Case 35: Table 1. Note that a key feature of
the diagnosis is unsteadiness while standing rather than unsteadiness while walking.

250
 CASE 35: ORTHOSTATIC TREMOR 251

Case 35: Table 1 Typical Symptoms and Signs of Orthostatic Tremor

Onset of unsteadiness within 1 minute of standing

Progressive unsteadiness while standing still
Complaint of fear of falling
Complaint of stiffness
Stress increases the tremor
Tremor increases with prolonged standing
May be unable to walk slowly
Normal neurologic examination except tremor of legs while standing

The tremor may worsen in the Romberg position. Also, patients with orthostatic tremor
may have a wide-based stance and yet are able to stand with the eyes closed without
falling.
Orthostatic tremor is a clinical diagnosis. Most patients present with a high-frequency
tremor primarily in the lower extremities of approximately 14 to 16 Hz.4,5 The tremor
may be a result of a synchronous co-contraction of the agonist and antagonist muscles
of the legs or a result of alternately firing antagonists and antagonists. Typically, ortho-
static tremor is difficult to see visually but it can be palpated, especially in the calves.

Laboratory Testing

Videonystagmography: Ocular motor function was normal. There was no positional

nystagmus, and caloric responses were normal.
Rotational responses were normal.
The amount of sway during posturography was normal. However, the patient’s record
during posturography revealed extremely high shear (horizontal) forces.
Vestibular-evoked myogenic potentials were normal.
An MRI scan of the brain revealed deep white matter changes consistent with the
patient’s age.
Question 3: What further diagnostic information is available from the results of laboratory
testing?
Answer 3: Laboratory testing confirmed the absence of a demonstrable vestibular
abnormality. Also, posturography disclosed an unusual finding in the shear (hor-
izontal) forces.6 High-frequency shear forces have been seen with orthostatic tre-
mor, and this further supports the diagnosis. A definitive diagnosis of orthostatic
tremor requires electromyography. The patient’s MRI scan, consistent with his age,
revealed nonspecific abnormalities. Although disequilibrium of aging (see Case 10)
is associated with deep white matter lesions, this patient’s history and physical
examination did not suggest a diagnosis of disequilibrium of aging, although an
added effect of age must be considered.

Diagnosis/Differential Diagnosis

The patient was given a diagnosis of orthostatic tremor.

Question 4: What treatments should be considered for a patient with orthostatic tremor?
252 VESTIBULAR DISORDERS

Answer 4: Various medications have been used to treat orthostatic tremor. The most
common ones include clonazepam, primidone, phenobarbital, valproic acid, clor-
azepate, gabapentin, propranolol, and carbidopa-levodopa. Gabapentin is cur-
rently the medication of choice for the treatment of orthostatic tremor.7,8,9 In our
experience, clonazepam is another medication that has been used successfully,
although it appears that gabapentin is better for persons with orthostatic tremor.
Vestibular rehabilitation may be a useful adjunct to pharmacotherapy in these
patients.

Treatment

The patient was treated with gabapentin, 100 mg three times a day, and was referred for
vestibular rehabilitation.

Follow-Up

Three months following initiation of treatment with gabapentin and vestibular rehabilita-
tion, the patient reported that his symptoms were decreased, though still present.

Summary

A 70-year-old man presented with the complaint of unsteadiness while standing He was
asymptomatic when sitting or walking. There was no dizziness. Neurologic examination
revealed a palpable tremor in the lower extremities while the patient was standing. During
posturography, the patient was noted to have extremely high shear (horizontal) forces. He
was given a diagnosis of orthostatic tremor. The patient was treated with gabapentin,
100 mg three times a day, and was referred for vestibular rehabilitation. Three months
following initiation of treatment with gabapentin and vestibular rehabilitation, the patient
reported that his symptoms were decreased, though still present.

Teaching Points

1. Orthostatic tremor is a very unusual disorder characterized by unsteadiness while

standing but not while walking. The tremor may worsen in the Romberg position.
Patients may have a wide-based stance and are able to stand with the eyes closed
without falling. Typically, orthostatic tremor is difficult to see visually but it can be
palpated, especially in the calves.
2. Treatment options for orthostatic tremor include pharmacotherapy, for example,
with gabapentin. Vestibular rehabilitation may be a useful adjunct to pharmacotherapy
in patients with orthostatic tremor.

References

1. Heilman KM: Orthostatic tremor. Arch Neurol 41:880–881, 1984.

2. Britton TC, Thompson PD, van der Kamp W, Rothwell JC, Day BL, Findley LJ, Marsden CD:
Primary orthostatic tremor: Further observation in six cases. J Neurol 239:209–217, 1992.
 CASE 35: ORTHOSTATIC TREMOR 253

3. Veilleux M, Sharbrough FW, Kelly JJ, Westmoreland BF, Daube JR: Shaky-legs syndrome.
J Clin Neurophysiol 4(3):304–305, 1987.
4. Thompson PD: Orthostatic tremor. J Neurol Neurosurg Psychiatry 66:278, 1999.
5. Yarrow K, Brown P, Gresty MA, Bronstein AM: Force platform recordings in the diagnosis of
primary orthostatic tremor. Gait Posture, 13(1):27–34, 2001.
6. Whitney SL, Wrisley DM, Musolino MC, Furman JM: Orthostatic tremor: Three patients in a
vestibular rehabilitation practice. Neurology Report 2003, 27(2):46–53.
7. Evidente VG, Adler CH, Caviness JN, Gwinn KA: Effective treatment of orthostatic tremor
with gabapentin. Movement Dis 13(5):829–831, 1998.
8. Onofrj M, Thomas A, Paci CF, D’Andreamatteo G: Gabapentin in orthostatic tremor: Results
of a double-blind crossover with placebo in four patients. Neurology 51:880–882, 1998.
9. Rodrigues JP, Edwards DJ, Walters SE, Byrnes ML, Thickbroom GW, Stell R, Mastaglia FL:
Blinded placebo crossover study of gabapentin in primary orthostatic tremor. Mov Disord
21(7):900–905, 2006.
Case 36
Mal de Débarquement
Syndrome

History

A 45-year-old female molecular biologist complained of persistent dizziness after a 1-week

pleasure cruise in the Caribbean 6 weeks before evaluation. The patient had no prior history
of dizziness or disequilibrium and used no medications. During her vacation, she had a sense
of malaise and motion sickness while on board ship. These symptoms were mild, not
associated with vomiting, and treated successfully by the ship’s doctor with medication
that she wore as a patch behind her ear (most likely scopolamine). The patient noted that
while returning home, she was bothered by motion sickness during air travel. She had not
experienced air sickness previously. Following her arrival home, the patient noted a persis-
tent rocking sensation. She had no complaints of hearing loss, tinnitus, or fullness in the ears.
The patient had no significant family history. Meclizine had been prescribed but was not
helpful. An MRI scan, requested by the patient’s primary care physician, was normal.
Question 1: Based on the patient’s history, what are the diagnostic considerations?
Answer 1: This patient has persistent complaints referable to the vestibular system
following a sea voyage. Diagnostic considerations include a vestibulopathy or some
other balance disorder that coincidentally began during the patient’s travel or
an unusual syndrome known as mal de débarquement. Mal de débarquement
syndrome has been defined as ‘‘sensations of motion experienced on return to stable
land after adaptation to motion lasting from hours to days for normal individuals.’’1

Physical Examination

The general, neurologic, otologic, and neurotologic examinations were normal.

Laboratory Testing

Videonystagmography: Ocular motor, positional, and caloric tests were normal.

Rotational test was normal.

254
 CASE 36: MAL DE DÉBARQUEMENT SYNDROME 255

Posturography was normal.

Vestibular-evoked myogenic potentials were normal.
An MRI scan of the brain, which the patient underwent prior to evaluation, was normal.

Diagnosis/Differential Diagnosis

This patient was given the diagnosis of mal de débarquement syndrome.

Question 2: What is the pathophysiologic basis of mal de débarquement syndrome?
Answer 2: Mal de débarquement syndrome probably results from the ability of the
vestibular system to adapt to various motion environments that include combin-
ations of vestibular and visual stimuli. Animal studies have suggested that even
vestibular-induced nystagmus can continue beyond the cessation of a repetitive
stimulus.2 The existence of a rare ocular motor disorder known as periodic
alternating nystagmus 3 suggests that the human vestibular system can oscillate
indefinitely. Possibly, patients with mal de débarquement syndrome have
adapted to an environment that is no longer present and cannot ‘‘unadapt.’’
That is, they have adapted to the environment on board ship, and this is no longer
appropriate for dry land. The precise origin of mal de débarquement syndrome is
uncertain. Such factors as the otolith organs, hormonal factors, and central
nervous system abnormalities have been postulated but not proven to be related
to the syndrome.4,5

Treatment/Management

Question 3: What treatments should be considered for mal de débarquement syndrome?

Answer 3: Considerations for treatment of mal de débarquement syndrome include
vestibular suppressants such as meclizine and promethazine, anxiolytics such as
diazepam and clonazepam, antidepressants such as amitriptyline, and the carbonic
anhydrase inhibitor acetazolamide.4
Before evaluation, the patient failed treatment with meclizine. Low-dose diazepam,
2 mg orally twice a day, was prescribed, with some benefit. The patient was also enrolled
in a course of vestibular rehabilitation therapy. She was advised to avoid further pro-
longed exposure to motion environments. Over the next 3 to 6 months, her symptoms
gradually declined.

Summary

A 45-year-old woman presented with the complaint of 6 weeks of persistent dizziness and
disequilibrium characterized by a sense of rocking and imbalance that began following a
1-week sea voyage. The patient did not gain relief from meclizine. Physical examination,
brain imaging findings, and vestibular laboratory tests were all normal. She was given a
diagnosis of mal de débarquement syndrome. Low-dose diazepam and a vestibular
rehabilitation therapy provided some relief. The patient’s symptoms gradually declined
over 3 to 6 months.
256 VESTIBULAR DISORDERS

Teaching Points

1. Mal de débarquement syndrome is an unusual disorder defined as a sensation of

motion experienced on return to stable land after adaptation to motion, lasting
from hours to days for normal individuals.1
2. The pathophysiology of mal de débarquement syndrome is probably related to the
ability of the vestibular system to adapt to various motion environments that
include combinations of vestibular and visual stimuli.
3. Treatments for mal de débarquement syndrome include vestibular suppressants
anxiolytics, antidepressants, and acetazolamide. Most cases of mal de débarquement
syndrome resolve spontaneously within weeks to months.

References

1. Brown JJ, Baloh RW: Persistent mal de débarquement syndrome: A motion-induced sub-
jective disorder of balance. Acta Otolaryngol 8:219–222, 1987.
2. Von Baumgarten RJ: Plasticity in the nervous system at the unitary level. In: Schmitt FO (ed).
The Neurosciences: Second Study Program. New York: Rockefeller University, 1970, pp
260–271.
3. Leigh RJ, Zee DS: The Neurology of Eye Movements, ed 4. New York: Oxford University
Press, 2006.
4. Murphy TP: Mal de débarquement syndrome: A forgotten entity? Otolaryngol Head Neck
Surg 109:10–13, 1993.
5. Cha YH, Brodsky J, Ishiyama G, Sabbati C, Baloh RW: Clinical features and associated
syndromes of mal de debarquement. J Neurol 255(7):1038–1044, 2008.
Case 37
Wallenberg’s Syndrome—
Posterior Inferior Cerebellar
Artery Syndrome

History

A 55-year-old male high school teacher presented with an acute onset of severe disequili-
brium 1 week before evaluation that was characterized by a sensation of being pushed to
the ground from the left. The patient also complained of vertigo, nausea, blurred vision, and
an inability to stand without assistance. His symptoms were constant. There was no
associated hearing loss or tinnitus. His medical history was significant for hypertension.
The family history was significant for cerebral vascular disease.
Question 1: Based on the patient’s history, what is the likely diagnosis?
Answer 1: The patient’s history suggests a vestibular system abnormality. The
presence of an illusionary sensation of movement, visual impairment, and postural
instability suggests a vestibular system problem but does not allow localization to
either the central or peripheral vestibular system.
The patient’s complaint of feeling pushed to the ground, so-called lateropulsion,
and persistent symptoms for 1 week suggest a central rather than peripheral vestibular
abnormality. Moreover, the patient’s history of hypertension suggests that he may
have cerebral vascular disease. Thus, the most likely diagnosis is an acute vascular
insult involving central vestibular structures. However, the differential diagnosis is
very broad and includes both peripheral and central vestibular disorders.

Physical Examination

The patient had a normal general examination except for mildly elevated blood pres-
sure. He was awake and alert. A right gaze preference was observed when the patient
was distracted, but when he was encouraged to look straight ahead or to the left, he
could do so. When asked to look from side to side, the patient exhibited saccadic
lateropulsion, a condition characterized by excessively large saccades in one direction
(known as overshoot dysmetria or saccadic hypermetria) and excessively small sac-
cades in the other direction (known as undershoot dysmetria or saccadic hypometria). In

257
258 VESTIBULAR DISORDERS

this patient’s case, the saccadic overshoots were seen when looking from left to right,
and the undershoots were seen when looking from right to left. The patient had
asymmetrically impaired ocular pursuit: there was more difficulty pursuing targets
moving to the left. With his eyes open in the light, he had a low-amplitude primary-
position left-beating nystagmus that increased on left gaze. On right gaze, however, the
nystagmus became right-beating and was coarse, that is, low frequency with a large
position amplitude. It was clearly different from the nystagmus seen in the primary
position, which was fine, that is, high frequency with a small position amplitude. The
patient was noted to have diminished sensation on the right side of the face. He had no
asymmetry of facial movement. The gag reflex was diminished. Strength was normal.
Dysmetria was seen in the right upper extremity on finger-to-nose testing. Sensation to
pain and temperature was diminished on the left side of the body, including the left arm
and left leg. The patient was unable to stand without assistance, and when walking,
which he could do only with assistance, he had a wide-based gait. Otologic examination
was normal.
Question 2: Based on the patient’s physical examination, what physiologic mechan-
isms have been disrupted, and what is the most likely localization of this patient’s
lesion?
Answer 2: The patient’s right gaze preference suggests that tonic drive to the medial
and lateral rectus muscles is unequal. Such an imbalance could be the result of an
acute lesion affecting mechanisms that drive the eyes to the left, for example, an
abnormality in the right frontal eye fields, or in the left pontine gaze center, which
includes the paramedian pontine reticular formation. The saccadic lateropulsion
suggests an interruption of cerebellar pathways that control saccadic accuracy.1
This patient’s history and physical examination suggest a brainstem abnormality
because of the combination of a dissociated sensory loss, that is, a loss of pain and
temperature sensation with preservation of touch and position sensation; incoordi-
nation; abnormal eye movements; and subjective lateropulsion as well as saccadic
lateropulsion. The patient’s left-beating primary-position nystagmus, which
increased on left lateral gaze, is a vestibular nystagmus that suggests a vestibular
system abnormality characterized by diminution of the drive coming from the right
vestibular system.2 The patient’s coarse nystagmus on right gaze is probably a gaze-
evoked nystagmus resulting from brainstem or cerebellar system involvement on
the right. Given the other features of this patient’s condition, it is likely that central
vestibular structures, including the vestibular nuclei in the right medulla, have been
damaged.

Question 3: How can this patient’s signs and symptoms be explained by damage to central
vestibular pathways?
Answer 3: This patient’s right gaze preference suggests that the tonic balance
between the left and right vestibular nuclei has been disrupted so that the eyes are
being driven slowly to the right. The left-beating nystagmus is a result of this tonic
imbalance interrupted by rapid eye movements (quick components of nystag-
mus) to the left. An acute vestibular imbalance with resulting vestibulospinal
difficulties also accounts for the patient’s inability to stand or walk without
assistance. The patient’s complaints of nausea are probably related to a vestibu-
loautonomic imbalance. The complaint of feeling pushed to the ground may
be related to erroneous signals to the cerebral cortex via vestibulocortical
projections.
 CASE 37: WALLENBERG’S SYNDROME 259

Laboratory Testing

An MRI scan of the brain revealed increased T2 signal intensity in the right lateral medulla,
with no other abnormality seen.

Diagnosis/Differential Diagnosis

Question 4: What is this patient’s diagnosis? What other lesions present similarly?
Answer 4: It is likely that this patient suffered an ischemic infarction in the territory of
the posterior inferior cerebellar artery, that is, a lateral medullary infarction, also
known as Wallenberg’s syndrome. Other conditions that can present similarly
include the anterior inferior cerebellar artery syndrome (see Case 30).
Distinguishing between the lateral medullary syndrome and the syndrome of the
anterior inferior cerebellar artery can be difficult (see Table Case 38-1). However,
the character of the patient’s nystagmus, that is, a vestibular nystagmus combined
with gaze-evoked nystagmus, the lack of hearing loss, and the location of the
abnormality as seen on MRI make lateral medullary syndrome the most likely
diagnosis.3 Although other lesions such as demyelination and neoplasia rarely
present similarly to Wallenberg’s syndrome, these diagnoses are most unlikely
because of the acute onset of this patient’s symptoms and signs and the findings
on the MRI scan.
The patient was diagnosed as having Wallenberg’s syndrome caused by an
infarction in the territory of the posterior inferior cerebellar artery. Because the
window of opportunity to treat with thrombolytic therapy4 had passed, the patient
was treated with an antiplatelet agen and was referred for vestibular rehabilitation.

Treatment/Management

This patient was treated with antihypertensive agents and aspirin, one tablet per day.

Summary

A 55-year-old hypertensive man presented with the acute onset of vertigo, nausea, dis-
equilibrium, and blurred vision. Examination revealed signs characteristic of the lateral
medullary syndrome, including nystagmus, limb dysmetria, and contralateral impairment
of pain and temperature. An MRI scan confirmed a right lateral medullary infarction.
Treatment consisted of blood pressure control and an antiplatelet agent.

Teaching Points

1. The central vestibular system is composed of several structures and pathways.

These include the vestibular nuclei, vestibulo-ocular pathways, vestibulospinal pathways,
vestibuloautonomic pathways, vestibulocortical pathways, vestibulocerebellum, and
other associated structures, such as the perihypoglossal nuclei.
260 VESTIBULAR DISORDERS

2. Lateropulsion, a feeling of being pushed or pulled to the ground, suggests a central

vestibular abnormality.
3. An acute central vestibular imbalance can mimic an acute peripheral vestibular
ailment. Signs and symptoms may include (1) nystagmus, because of an abnormal
vestibulo-ocular reflex; (2) an inability to stand or walk without assistance because of
vestibulospinal difficulties; (3) nausea, because of vestibuloautonomic imbalance; and
(4) subjective lateropulsion, that is, the sensation of being pushed to the ground, because
of erroneous signals in vestibulocortical projections.
4. Wallenberg’s syndrome is caused by a lesion in the lateral medulla, usually an
infarction in the territory of the posterior inferior cerebellar artery. Patients
typically present with the acute onset of a vestibular imbalance in the presence of
unequivocal central nervous system symptoms or signs suggestive of lateral medullary
infarction.

References

1. Leigh RJ, Zee DS: The Neurology of Eye Movements, ed 4. New York: Oxford University
Press, 2006.
2. Baloh RW, Yee RD, Honrubia V: Eye movements in patients with Wallenberg’s syndrome.
Ann NY Acad Sci 374:600–614, 1981.
3. Amarenco P, Rosengart A, DeWitt LD, Pessin MS, Caplan LR: Anterior inferior cerebellar
artery infarcts. Arch Neurol 50:154–161, 1993.
4. Khurana D, Saini M, Khandelwal N, Prabhakar S: Thrombolysis in a case of lateral
meduallary syndrome: CT angiographic findings. Neurology 64(7):1232, 2005.
Case 38
Anterior Inferior Cerebellar
Artery Syndrome

History

A 60-year-old man who worked as a building custodian presented with the acute onset of
vertigo, hearing loss, and tinnitus in the left ear, left facial weakness; and disequilibrium.
The patient experienced blurred vision and mild nausea. There was no complaint of loss of
strength, but he complained of great difficulty ambulating and noted veering to the left. His
medical history was significant for hypertension. The family history was not contributory.
The patient’s family rushed him to a local emergency room, where a CT scan of the head
was interpreted as within normal limits.
Question 1: Based upon the patient’s history, where is his lesion located and what is the
differential diagnosis?
Answer 1: The patient’s complaints of vertigo, hearing loss, and tinnitus suggest an
acute peripheral vestibular lesion. However, the facial weakness and disequilibrium
suggest a central abnormality. Diagnostic possibilities include brainstem or cere-
bellar infarction or hemorrhage, an infectious process such as herpes zoster oticus,
and a peripheral vestibular ailment.

Physical Examination

The patient’s general examination was normal aside from an elevated blood pressure of
150/100. The cranial nerve examination revealed an inability to move his eyes to the left.
He had left facial weakness affecting the entire left side of the face and decreased sensation
on the left side of the face. Strength was normal. There was left upper and lower extremity
dysmetria. Sensation was reduced for pain and temperature in the right arm and leg. He
could not stand or walk unassisted. Otoscopy was normal. On tuning-fork testing, Weber’s
test showed lateralization to the right and the Rinne test was positive on the right, indicating
a sensorineural hearing in the left ear. On neurotologic examination, right-beating nystag-
mus was seen with infrared goggles.
Question 2: Based on the history and physical examination, what is the likely diagnosis and
what further diagnostic studies would be helpful?

261
262 VESTIBULAR DISORDERS

Answer 2: This patient’s examination is consistent with a lesion of the brainstem and
cerebellum. However, the vertigo, tinnitus, hearing loss, and spontaneous nystag-
mus suggest a peripheral otologic lesion.
The most likely diagnosis is an infarction in the territory of the anterior inferior
cerebellar artery, because this artery supplies the inner ear, lateral pons, and middle
cerebellar peduncle.2,3 Further diagnostic information should be obtained from an MRI
scan. Audiometric and vestibulo-ocular testing would also help confirm this diagnosis.

Laboratory Testing

Videonystagmography: There was an inability to move the eyes to the left. A right-beating
nystagmus was seen during loss of visual fixation. Caloric responses were absent on the left.
Audiometric testing revealed complete deafness on the left and normal hearing on the right.
An MRI scan of the brain showed evidence of acute infarction in the territory of the anterior
inferior cerebellar artery involving the lateral pons and adjacent middle cerebellar peduncle.

Diagnosis/Differential Diagnosis

This patient was given the diagnosis of an infarction in the territory of the anterior inferior
cerebellar artery.
Question 3: What arteries supply the vestibular system, including the peripheral labyrinth,
and central vestibular structures, including the vestibulocerebellum?
Answer 3: The arterial supply of the labyrinth arises from the labyrinthine artery,
which arises from the anterior inferior cerebellar artery, the first branch of the basilar
artery (Case 38: Figure 1). Case 38: Figure 2A,B3 indicates that the vestibular nerve,

Case 38: Figure 1 Arterial supply to the inner ear.

Source: Modified by permission of the publisher from Schuknecht HF: Pathology of the Ear. Cambridge:
Harvard University Press, Copyright 1974 by the President and Fellows of Harvard College, p 62.1
Case 38: Figure 2 Vascular distribution of the anterior inferior cerebellar artery (AICA).
(A) Line drawing of an axial section through the brainstem showing the major anatomic
structures of the brainstem supplied by the AICA. The shaded region represents the region of the
brainstem supplied by the AICA. (B) Line drawing of an anterior view of the cerebellum.
Shaded areas represent regions supplied by AICA.
Source: Modified with permission from Oas JG, Baloh RW: Vertigo and the anterior inferior cerebellar
artery syndrome. Neurology 42:2274–2279, 1992, p 2276.2

263
264 VESTIBULAR DISORDERS

Case 38: Table 1 Comparison of Posterior-Inferior Cerebellar Artery (PICA) and Anterior-Inferior
Cerebellar Artery (AICA) Syndromes

Seen in Both PICA and Typically Seen Only Typically Seen Only in
AICA Sydromes in PICA Sydrome AICA Syndrome

Symptoms Vertigo, lateropulsion, Hoarseness Tinnitus, hearing loss, and

unusual visual illusions facial weakness
(e.g., tilting), facial
numbness, limb
numbness,
disequilibrium,
dysphagia, and
incoordination
Signs Vestibular nystagmus, Saccadic lateropulsion, Hearing loss, facial
decreased facial i.e., saccades that are weakness, and gaze palsy
sensation ipsilaterally, too large when
sensory loss to pain and looking in one
temperature direction horizontally,
contralaterally, and too small when
Horner’s syndrome, looking in the other
ipsilateral limb ataxia, direction, skew
and gait ataxia deviation, and vocal
cord paralysis
Laboratory Abnormal imaging, Saccadic lateropulsion Caloric reduction
Abnormalities spontaneous nystagmus, ipsilaterally
and decreased hearing
Pathophysiology Damage of fifth nerve Damage of nucleus Damage of inner ear,
nucleus, spinothalamic ambiguus and dorsal eighth cranial nerve,
tract, and vestibular motor nucleus seventh cranial nerve,
nuclei seventh and eighth cranial
nerve root-entry zones,
sixth nerve nucleus,
flocculus, and middle
cerebellar peduncle

the vestibular root-entry zone, and the cerebellar flocculus are all supplied by the
anterior inferior cerebellar artery.4 The vestibular nuclei, deep cerebellar nuclei, and
inferior vermis are supplied by the posterior inferior cerebellar artery5 (see Case 37).
Question 4: How does the lateral medullary syndrome differ from the anterior inferior
cerebellar artery syndrome?
Answer 4: The lateral medullary syndrome (i.e., Wallenberg’s syndrome) (see
Case 37) results from infarction in the territory of the posterior inferior cerebellar
artery, which supplies a different region of the brain from the anterior inferior
cerebellar artery. Although some of the presenting symptoms and signs of the
lateral medullary syndrome and the anterior inferior cerebellar artery syndrome
are the same, there are distinct and significant differences. Case 38: Table 1 lists
these similarities and differences and their pathophysiologic origin.2,3,4,5

Treatment/Management

The patient was treated with supportive measures, anti-hypertensive agents, and aspirin as
an antiplatelet agent and referred for vestibular rehabilitation.
 CASE 38: ANTERIOR INFERIOR CEREBELLAR ARTERY SYNDROME 265

Summary

A 60-year-old man presented with the acute onset of vertigo, left-sided hearing loss and
tinnitus, left facial weakness, and disequilibrium. His medical history was significant for
hypertension. Physical examination revealed left-sided hearing loss, an inability to move
the eyes to the left, and abnormal sensation on the left side of the face and in the right arm
and leg. MRI indicated infarction in the territory of the anterior inferior cerebellar artery,
which was thought to account for all of the patient’s symptoms. Treatment consisted of
supportive measures and an antiplatelet agent.

Teaching Points

1. The arterial supply of the inner ear arises from the labyrinthine artery, which
arises from the anterior inferior cerebellar artery, the first branch of the basilar
artery.
2. The anterior inferior cerebellar artery supplies the inner ear, the vestibular nerve,
the vestibular root-entry zone, the lateral pons, the middle cerebellar peduncle,
and the cerebellar flocculus.
3. Infarction in the territory of the anterior inferior cerebellar artery produces a
syndrome of acute vertigo, tinnitus, and hearing loss because of interruption of the
vascular supply to the inner ear and its nerves. Neurologic abnormalities including
ipsilateral facial nerve paralysis, contralateral reduced pain and temperature sensation,
and ipsilateral upper- and lower-extremity dysmetria are consistent with a lesion of the
brainstem and cerebellum.
4. The anterior inferior cerebellar artery syndrome shares many of the clinical
features of the lateral medullary syndrome (i.e., Wallenberg’s syndrome), which
results from infarction in the territory of the posterior inferior cerebellar artery.
Although some of the presenting symptoms and signs of the lateral medullary syndrome
and the anterior inferior cerebellar artery syndrome are the same, there are distinct and
significant differences (Case 38: Table 1).

References
1. Schuknecht HF: Pathology of the Ear. Cambridge: Harvard University Press, 1974.
2. Oas JG, Baloh RW: Vertigo and the anterior inferior cerebellar artery syndrome. Neurology
42:2274–2279, 1992.
3. Amarenco P, Rosengart A, DeWitt LD, Pessin MS, Caplan LR: Anterior inferior cerebellar
artery territory infarcts. Arch Neurol 50:154–161, 1993.
4. Amarenco P, Hauw J-J: Cerebellar infarction in the territory of the anterior and inferior
cerebellar artery. Brain 113:139–155, 1990.
5. Gilman S, Bloedel JR, Lechtenberg R (eds): Disorders of the Cerebellum. Contemporary
Neurology Series. Philadelphia: FA Davis, 1981.
Case 39
Benign Paroxysmal
Positional Vertigo-Surgical
Management

History

A 70-year-old retired woman complained of bouts of vertigo that occurred daily for
8 months before evaluation. The patient reported that vertigo could be provoked by lying
down in bed, rolling over in bed, or getting out of bed. She expressed a fear of falling and
was unable to leave her home because of fear of her vertigo. The patient reported that
similar vertiginous episodes had recurred intermittently for the previous 20 years.
Recently, the patient was treated using particle-repositioning maneuvers (see Case 7).
Although the maneuvers were repeated at six different office visits, she continued to suffer
from positional vertigo. After the particle-repositioning maneuvers failed, the patient
underwent a 3-month course of vestibular rehabilitation therapy that focused on Brandt-
Daroff exercises with repeated particle repositioning maneuvers. After the course of
physical therapy, the positional vertigo continued unabated.
Question 1: This patient reported a 20-year history of symptoms consistent with benign
paroxysmal positional vertigo. Is it unusual for benign positional vertigo to persist this
long?
Answer 1: A history of recurrent periods of positional vertigo spanning 20 years
is not unusual. Studies of the natural history of benign paroxysmal positional
vertigo show that up to 25% of patients with this condition report symptoms
that have persisted for more than 1 year, and many report vertigo lasting for
5 to 20 years.1 Most patients have symptoms intermittently, but occasionally
some have positional vertigo that is always present. These individuals have
learned never to sleep on the affected side, bend over, or pitch their head
backward. Interestingly, by sleeping with the head turned away from the
affected side, these individuals have probably inadvertently prolonged their
vertigo, because the presumed free-floating endolymph particles that cause
benign paroxysmal positional vertigo never have a chance to escape the poster-
ior semicircular canal. Typically, periods of benign paroxysmal positional vertigo
can last for 6 to 8 weeks and then spontaneously disappear. Recurrent episodes
may occur several times each year.

266
 CASE 39: BENIGN PAROXYSMAL POSITIONAL VERTIGO-SURGICAL MANAGEMENT 267

Question 2: This patient presented with what appears to be typical benign paroxysmal
positional vertigo. However, the vertigo was unresponsive to treatment using particle-
repositioning maneuvers and physical therapy that included Brandt-Daroff exercises. Is
it unusual for benign paroxysmal positional vertigo to be unresponsive to these treat-
ments?
Answer 2: Benign paroxysmal positional vertigo that is unresponsive to particle-
repositioning maneuvers or to Brandt-Daroff exercises is unusual but does occa-
sionally occur. More commonly, the vertigo disappears either spontaneously or
after treatment but recurs later. It is estimated that approximately 15% of indivi-
duals with one episode of benign paroxysmal positional vertigo will have a recur-
rence within 1 year.2
Question 3: What other conditions should be considered in patients with benign parox-
ysmal positional vertigo that is unresponsive to treatment?
Answer 3: Even if a patient’s description is quite typical of benign paroxysmal positional
vertigo, it is important to rule out (1) a central nervous system cause of apparent
benign paroxysmal positional vertigo,3–5 (2) bilateral benign paroxysmal positional
vertigo, (3) horizontal semicircular canal benign paroxysmal positional vertigo (see
below), and (4) an associated chronic peripheral vestibular disorder other than benign
paroxysmal positional vertigo that is contributing to the patient’s symptoms.
Rarely, patients with symptoms and signs identical to those characteristic of benign
paroxysmal positional nystagmus and vertigo have been diagnosed as having a
brainstem neoplasm or brainstem infarction.4,5
Bilateral benign paroxysmal positional vertigo occurs infrequently in patients with
benign paroxysmal positional vertigo and can be ruled out by performing the Dix-
Hallpike maneuver with the head turned both to the right and to the left. If benign
paroxysmal positional vertigo is present bilaterally, sequential particle-repositioning
maneuvers can be performed.
Horizontal semicircular canal benign paroxysmal positional vertigo (HCBPPV),
presumably caused by debris in the horizontal rather than the posterior semicircular
canal,6 can be detected by placing the individual in the supine position and then
turning the head rapidly but not abruptly to the head right or right lateral position and
then quickly to the head left or left lateral position (see Case 28). HCBPPV produces
horizontal right-beating nystagmus with the head turned to the right and left-beating
nystagmus with the head turned to the left. HCBPPV can be seen in patients who have
undergone a particle-repositioning maneuver for typical, that is, posterior semicircular
canal benign paroxysmal positional vertigo. Presumably, these patients have debris
that moved from the posterior to the horizontal semicircular canal. HCBPPV can be
treated using a modified particle-repositioning maneuver (see Case 28).7
A peripheral vestibulopathy associated with benign paroxysmal positional vertigo is
not unusual,6 especially if the vertigo follows an acute labyrinthine disorder.
Presumably, an acute vestibulopathy, whether viral, traumatic, or other, can produce
degeneration within the inner ear, resulting in the formation of free-floating endo-
lymphatic debris that causes benign paroxysmal positional vertigo (see Case 7). Thus,
in a patient with symptoms that persist despite treatment for benign paroxysmal
positional vertigo, the symptoms may actually be due to the prior peripheral labyr-
inthine injury. The patient may not have fully compensated for a peripheral disorder,
or the peripheral disorder may be fluctuating, producing intermittent symptoms.
Such symptoms should be easily distinguished from those of typical benign paroxysmal
positional vertigo.
268 VESTIBULAR DISORDERS

Although benign paroxysmal positional vertigo is usually caused by free-floating

endolymph particles, it has been postulated that occasionally a fixed cupular density
may occur. In this situation, particle repositioning or exercises may not cause dispersion
of the cupular density. This situation is called cupulolithiasis rather than canalithiasis.
The direction of typical positional nystagmus and its fatigability, when present, are
difficult to explain physiologically using the cupulolithiasis theory. As a result, even the
existence of cupulolithiasis is now controversial.

Physical Examination

The patient’s neurologic and otologic examinations were normal. On neurotologic exam-
ination, performance of the Dix-Hallpike maneuver with the head turned to the right
provoked a torsional-upbeat nystagmus typical of benign paroxysmal positional vertigo.
The patient experienced vertigo. The nystagmus and vertigo began approximately
5 seconds following positioning and lasted for approximately 30 seconds. A particle-
repositioning maneuver was performed (see Case 7), but upon repeat Dix-Hallpike testing,
nystagmus and vertigo, although decreased in intensity, remained present. The Dix-Hallpike
test with the head turned to the left produced no vertigo or nystagmus. Testing for HCBPPV
(see Case 28) by rapidly but not abruptly shifting the patient to the head-left or head-right
position from the supine position was negative.

Laboratory Testing

Videonystagmography: Ocular motor and static positional tests were normal. However,
Dix-Hallpike tests produced vertigo and upbeating nystagmus typical of benign paroxysmal
positional vertigo in the head-hanging right position. The caloric test was normal.
Vestibular evoked myogenic potentials were normal.
An MRI scan of the brain was performed and was normal.
Question 4: Based on the additional information from physical examination and laboratory
testing, what are the diagnostic considerations?
Answer 4: This patient appears to have typical benign paroxysmal positional vertigo
that is refractory to conventional treatments. Examination and laboratory testing
have ruled out bilateral benign paroxysmal positional vertigo, HCBPPV, and a
posterior fossa lesion. An associated vestibulopathy is also unlikely.
Question 5: What surgical procedures are available for treatment of patients with benign
paroxysmal positional vertigo that has been unresponsive to treatment with physical
maneuvers?
Answer 5: Three surgical procedures have been performed for patients with benign
paroxysmal positional vertigo refractory to other nonsurgical treatments: (1)
singular neurectomy,8 (2) posterior semicircular canal ‘‘plugging’’ (occlusion)9
(Case 39: Figure 1), and (3) vestibular nerve section.10 Because the singular nerve
is composed of only eighth nerve afferent fibers that innervate the ampulla of the
posterior semicircular canal, singular neurectomy, a procedure in which the singu-
lar nerve is selectively sectioned, removes all afferent activity arising from the
posterior semicircular canal. Posterior semicircular canal plugging is a procedure
in which the bony posterior semicircular canal is opened surgically and then
occluded with bone wax or a ‘‘pâte’’ of bone dust and fibrin glue. This procedure
 CASE 39: BENIGN PAROXYSMAL POSITIONAL VERTIGO-SURGICAL MANAGEMENT 269

Case 39: Figure 1 Semicircular canal plugging for benign paroxysmal positional vertigo.
(A) The posterior semicircular canal is exposed within the mastoid cavity, and a small oval
island of bone is drilled free. (B) The island of bone is removed with a pick, revealing the
perilymphatic and endolymphatic compartments within the bony semicircular canal. (C) Bone
wax or bone pâte is then inserted into the opening in the semicircular canal. (D) Plugging of the
bony canal results in compression and occlusion of the endolymphatic compartment, which
physiologically inactivates the posterior semicircular canal.
Source: With permission from Hirsch BE et al: Translabyrinthine approach to skull base tumors with
hearing preservation. Am J Otol 14(6):533–543, 1993. 11

inactivates the posterior semicircular canal ampulla and is not associated with
hearing loss.12 Vestibular nerve section involves sectioning of the entire vestibular
nerve (see also Case 42).
Question 6: How do these three alternative surgical procedures address the underlying
pathophysiology of benign paroxysmal positional vertigo?
Answer 6: Singular neurectomy takes advantage of the fact that the posterior
semicircular canal ampulla is abnormally stimulated in patients with benign
paroxysmal positional vertigo. Thus, by sectioning the afferent nerve to the
posterior canal ampulla, erroneous signals resulting from abnormal stimulation
of the posterior semicircular canal that occurs with certain head movements are
not transmitted to the central nervous system, and thus vertigo and nystagmus
are prevented. Occlusion (plugging) of the posterior semicircular canal (Case 39:
Figure 1) prevents the flow of endolymph in the posterior semicircular canal.
When endolymph flow is prevented, the posterior semicircular canal is effec-
tively inactivated. Thus, free-floating particles either become locked in place
and cannot provoke vertigo with head movement or are no longer able to
cause deflection of the posterior semicircular canal cupula because they are
physically separated from the ampulla. Vestibular nerve section does not
270 VESTIBULAR DISORDERS

specifically address the pathophysiology of benign paroxysmal positional ver-

tigo and is generally not indicated for patients with this form of vertigo
because the procedure results in denervation of the entire vestibular portion
of the inner ear. However, vestibular nerve section may be indicated in
selected patients with concomitant labyrinthine dysfunction in addition to
benign paroxysmal positional vertigo.
Question 7: How often is a surgical remedy required for benign paroxysmal positional
vertigo?
Answer 7: Fewer than 1 in 100 cases of benign paroxysmal positional vertigo require
surgical13 intervention. Both the natural history of this vertigo and the success of
particle-repositioning maneuvers and vestibular exercises ensure that most of these
patients can be cured without surgery.
Question 8: How successful is semicircular canal occlusion surgery?
Answer 8: Several studies show that the success rate of posterior semicircular canal
occlusion for recurrent or recalcitrant BPPV is greater than 95%. Temporary con-
ductive and/or sensorineural hearing loss can occur in up to 50% of cases but
permanent hearing loss is a rare occurrence. Transient imbalance for up to 4 weeks
post surgery is common and protracted imbalance after surgery can occur as
well.13–15

Diagnosis/Differential Diagnosis

This patient has benign paroxysmal positional vertigo recalcitrant to medical management.
Causes other than a unilateral posterior semicircular canal lesion, including a central
nervous system disease, bilateral benign paroxysmal positional vertigo, HCBPPV, and
an associated labyrinthine injury, were ruled out.

Treatment/Management

This patient was successfully treated with surgical occlusion (plugging) of the posterior
semicircular canal. Hearing remained normal. In the immediate postoperative period, she
had mild disequilibrium that was treated with additional physical therapy. Three months
after treatment, the patient was asymptomatic.

Summary

A 70-year-old retired woman with a complaint of positional vertigo was diagnosed as

having benign paroxysmal positional vertigo. The patient’s condition was unresponsive
to physical therapy, including particle-repositioning maneuvers and Brandt-Daroff
exercises. Central nervous system causes of apparent benign paroxysmal positional
vertigo, associated labyrinthine dysfunction, bilateral benign paroxysmal positional
vertigo, and HCBPPV were all ruled out. A semicircular canal occlusion (plugging)
procedure was performed. The patient was cured of her benign paroxysmal positional
vertigo.
 CASE 39: BENIGN PAROXYSMAL POSITIONAL VERTIGO-SURGICAL MANAGEMENT 271

Teaching Points

1. Benign paroxysmal positional vertigo may be long-standing; 25% of these patients

report symptoms that have persisted for more than 1 year, and many report vertigo
lasting for 5 to 20 years. Most patients have intermittent symptoms, but some have
positional vertigo that is always present. Typically, periods of benign paroxysmal
positional vertigo can last for 6 to 8 weeks and then spontaneously disappear.
2. Benign paroxysmal positional vertigo may remit and then recur. It is estimated that
approximately 15% of individuals with one episode of benign paroxysmal positional
vertigo will have a recurrence within 1 year. Recurrent episodes may occur several
times each year.
3. Benign paroxysmal positional vertigo that is recalcitrant to treatment may be
caused by (1) a central nervous system abnormality that manifests as apparently
benign paroxysmal positional vertigo, (2) bilateral benign paroxysmal positional
vertigo, (3) HCBPPV, and (4) an associated chronic peripheral vestibular disorder
other than benign paroxysmal positional vertigo that is contributing to the
patient’s symptoms.
4. Surgery to treat BPPV is required in less than 1% of patients.
5. Posterior semicircular canal plugging (occlusion) is a safe and effective procedure
for intractable BPPV.

References

1. LeLiever WC: Comparative repositioning maneuvers for benign paroxysmal positional

vertigo. Proceedings of the Combined Otolaryngologic Spring Meeting, Palm Beach, Florida;
May 7–13, 1994.
2. Nunez RA, Cass SP, Furman JM: Short- and long-term outcomes of canalith repositioning for
benign paroxysmal positional vertigo. Otolaryngol Head Neck Surg 122(5):647–653, 2000.
3. Drachman DA, Diamond ER, Hart CW: Posturally-evoked vomiting: Association with
posterior fossa lesions. Ann Otol 86:97–101, 1977.
4. Watson P, Barber HO, Deck J, Terbrugge K: Positional vertigo and nystagmus of central
origin. J Can Sci Neurol 8:133, 1981.
5. Watson CP, Terbrugge K: Positional nystamus of the benign paroxysmal type with posterior
fossa medullobastoma. Arch Neurol 39:601–602, 1982.
6. Baloh RW, Honrubia V, Jacobson K: Benign positional vertigo: Clinical and oculographic
features in 240 cases. Neurology 37:371–378, 1987.
7. Baloh RW, Jacobson K, Honrubia V: Horizontal semicircular canal variant of benign
positional vertigo. Neurology 43:2542–2549, 1993.
8. Gacek RR: Singular neurectomy update II: Review of 102 cases. Laryngoscope 101:855–862,
1991.
9. Parnes LS, McClure JA: Posterior semicircular canal occlusion for intractable benign
paroxysmal positional vertigo. Ann Otol Rhinol Laryngol 99:330–334, 1990.
10. Cass SP, Kartush JM, Graham MD: Patterns of vestibular function following vestibular nerve
section. Laryngoscope 102:388–394, 1992.
11. Hirsch BE, Cass SP, Sekhar LN, Wright DC: Translabyrinthine approach to skull base tumors
with hearing preservation. Am J Otol 14(6):533–543, 1993.
12. Seo T, Hashimoto M, Saka N, Sakagami M: Hearing and vestibular functions after plugging
surgery for the posterior semicircular canal. Acta Otolaryngol [Epub ahead of spring] 2008.
13. Shaia WT, Zappia JJ, Bojrab DI, LaRouere ML, Sargent EW, Diaz RC: Success of posterior
semicircular canla occlusion and application of the dizziness handicap inventory. Otolaryngol
Head Neck Surg 134(3):424–430, 2006.
272 VESTIBULAR DISORDERS

14. Walsh RM, Bath AP, Cullen JR, Rutka JA: Long-term results of posterior semicircular canal
occlusion for intractable benign paroxysmal positional vertigo. Clin Otlaryngol Allied Sci
24(4):316–323, 1999.
15. Agrawal SK, Parnes LS: Human Experience with Canal Plugging. Ann NY Acad Sci
942:300–305, 2001.
Case 40
Drop Attacks

History

A 36-year-old female librarian presented with a complaint of episodic loss of balance.

These attacks had occurred approximately once each month during the 2 years before
evaluation. They were stereotyped and characterized by an abrupt loss of balance, causing
the patient to feel that she was being pulled to the ground. There was no associated vertigo
or nausea. The patient was unaware of any precipitating factors. No episodes occurred
while the patient was driving. However, on several occasions, she suffered bruises asso-
ciated with falling.
The patient was evaluated by her primary care physician, who was unable to reach a
diagnosis. That evaluation included a negative MRI scan of the brain and negative blood
studies including hematologic, metabolic, and rheumatologic parameters.
Question 1: What are the possible explanations for this patient’s attacks, and what further
historical information would be helpful?
Answer 1: The patient’s attacks of loss of balance could indicate brief episodes of loss
of consciousness. If the patient does not lose consciousness during the episodes, the
attacks should be labeled drop attacks, which have been defined as a falling spell
occurring without warning or postictal symptoms, with an immediate ability to
stand, and without loss of awareness or consciousness1,2 (see Case 40: Table 1).
Detailed questioning of the patient and her family regarding evidence of loss of
consciousness is essential. If the patient is suffering from episodic loss of conscious-
ness, her attacks should be labeled syncope.
Because the patient’s attacks occur monthly, any association with menses should
be ascertained. Additional important information includes the medical history,
especially of any otologic or neurologic abnormality, past or present medication
use, and family history.

Case 40: Table 1 Causes of Drop Attacks

Tumarkin’s otolithic crisis

Migraine
Epilepsy
Misinterpreted syncope

273
274 VESTIBULAR DISORDERS

Additional History

The patient and her family were adamant that the patient did not lose consciousness during
these episodes. Despite the abrupt onset and seemingly immediate fall of the patient to the
floor, she remembered each episode and was alert, oriented, and conversant immediately
afterward. There was no apparent postictal lethargy or confusion. The patient noted no
association between her episodes and menses. Her family history was significant. Her
mother and sister suffered from typical migraine headaches. Also, the patient’s history was
significant for ‘‘sick headaches’’ as a teenager, usually associated with menses. These
headaches had stopped approximately 15 years before evaluation, when the patient was in
her early 20s. She was not currently using any medications.
Question 2: What are the causes of drop attacks?
Answer 2: Drop attacks can be a manifestation of several disease states (Case 40:
Table 1), and their origin is often difficult to determine with certainty. In patients
with endolymphatic hydrops (see Cases 9, 12, 20, 24, 42), drop attacks some-
times occur and have been labeled Tumarkin’s otolithic crisis.3,4 Presumably, this
crisis results from abrupt alterations in otolithic function with concomitant
changes in the vestibulospinal system and loss of postural tone without an altera-
tion in level of consciousness. Drop attacks may also be a component of migraine
(see Cases 8, 20, 22, 23). Abrupt loss of postural tone could represent a migraine
aura akin to so-called basilar artery migraine, although this is quite unusual.
According to Meissner et al.,1 of 108 patients with drop attacks, 17 had migraines
with no other obvious cause. Drop attacks also can be seen in patients with partial
and generalized epilepsy. In addition to these possibilities, one should always be
concerned that a patient thought to have drop attacks is actually suffering from
syncopal episodes caused by vertebrobasilar insufficiency (see Case 33), postural
hypotension (see Case 27), and vasovagal syncope.

Physical Examination

The general, neurologic, otologic, and neurotologic examinations were normal.

Question 3: Based on the history and physical examination, what laboratory tests should be
ordered?
Answer 3: Based on the above discussion, laboratory tests should include vestibular
laboratory tests and an audiogram to search for subclinical hearing loss that may
suggest endolymphatic hydrops. Electrocochleography (see Chapter 5) should also
be considered to detect the presence of endolymphatic hydrops. The patient
should also undergo electroencephalography and Holter monitoring.

Laboratory Testing

Videonystagmography was normal.

Rotational testing was normal.
Posturography was normal.
An audiogram and electrocochleography were normal.
VEMPs were normal.
Electroencephalography and Holter monitoring were both normal.
 CASE 40: DROP ATTACKS 275

Diagnosis/Differential Diagnosis

Question 4: Based on the history, physical examination, and laboratory studies, what is this
patient’s most likely diagnosis?
Answer 4: The patient’s diagnosis is uncertain. An unusual variant of migraine or an
unusual presentation of endolymphatic hydrops are the most likely diagnoses.
The patient was given a diagnosis of drop attacks of uncertain etiology.

Treatment/Management

Question 5: Based on the differential diagnosis, what treatment, if any, should be instituted?
Answer 5: This patient should be treated for either endolymphatic hydrops or
migraine. Treatment for migraine with a migraine prophylactic agent poses little risk
to this patient, who has no other medical problems. Treatment for endolymphatic
hydrops with a diuretic and salt restriction also has little risk.

Follow-Up

The patient was advised to restrict her consumption of foods known to provoke migraine
(see Case 17: Table 1) and was treated with a combination of hydrochlorothiazide and
triamterene and salt restriction for possible endolymphatic hydrops. She continued to have
further episodes of loss of postural control for an additional 2 months. Diuretic therapy was
discontinued, and the patient was started on a calcium channel blocking agent. She
immediately noticed a reduction in the frequency of her attacks. The patient continued to
use this medication for 6 months, during which the attacks tapered off completely. She then
discontinued all medications and has been symptom-free.
Based on the patient’s response to therapy, she received the presumptive and uncertain
diagnosis of drop attacks in association with migraine.

Summary

A 36-year-old woman presented with episodes of abrupt loss of postural tone without loss
of consciousness. Episodes occurred approximately once each month but were not asso-
ciated with menses. An extensive evaluation did not uncover any objectifiable abnormalities.
The patient was treated presumptively for endolymphatic hydrops without success. She was
then treated with a calcium channel blocking agent. Her episodes resolved. Following
discontinuation of medication, the patient remained symptom-free.

Teaching Points

1. A drop attack is a falling spell occurring without warning or postictal symptoms,

with immediate righting, and without loss of awareness or consciousness. It is
essential that patients with presumed drop attacks be questioned carefully about even
brief episodes of loss of consciousness because this would suggest syncope, which has a
different and more ominous differential diagnosis.
276 VESTIBULAR DISORDERS

2. Drop attacks can be a manifestation of several disease states (see Case 40: Table 1),
and their cause is often difficult to determine with certainty.
3. Tumarkin’s otolithic crisis consists of drop attacks in some patients with
endolymphatic hydrops (Meniere’s disease). Presumably, Tumarkin’s otolithic
crises result from abrupt alterations in otolithic function. If a patient is believed to
have Tumarkin’s otolithic crisis, treatment for endolymphatic hydrops with a diuretic
and salt restriction is the most appropriate initial therapy.

References
1. Meissner I, Wiebers DO, Swanson JW, O’Fallon WM: The natural history of drop attacks.
Neurology 36:1029–1034, 1986.
2. Kubala MJ, Millikan CH: Diagnosis, pathogenesis, and treatment of ‘‘drop attacks.’’ Arch
Neurol 11:107–113, 1964.
3. Black FO, Effron MZ, Burns DS: Diagnosis and management of drop attacks of vestibular
origin: Tumarkin’s otolithic crisis. Otolaryngol Head Neck Surg 90:256–262, 1982.
4. Baloh RW, Jacobson K, Winder T: Drop attacks with Meniere’s syndrome: Ann Neurol
28:384–387, 1990.
Case 41
Ramsay Hunt Syndrome

History

A 55-year-old male physician presented with ear pain, hearing loss, vertigo, and progres-
sive facial paralysis. The symptoms began 3 days before evaluation with the acute onset of
severe left ear pain. Two days before evaluation, he had noticed distortion of hearing in the
left ear, tinnitus, and disequilibrium when he moved quickly. By that evening, he had
severe vertigo, nausea and vomiting, and a definite loss of hearing in the left ear. He also
noticed that he could not fully close his left eye, his smile was asymmetric, his voice had
become slightly hoarse, and his swallowing felt ‘‘funny.’’ Worried about a possible stroke,
he went to the emergency room for evaluation. The patient’s medical history and family
history were negative.
Question 1: What is the differential diagnosis for this patient’s combination of symptoms?
Answer 1: The combination of hearing loss, vertigo, facial paralysis, and bulbar symp-
toms suggests brainstem dysfunction, possibly as a result of cerebrovascular disease
(See Cases 37 and 38) or encephalitis. Another possibility is a cranial polyneuropathy.

Physical Examination

General examination was normal. Cranial nerve examination revealed full extraocular
movements. Saccadic and pursuit movements were normal. No nystagmus present with
visual fixation. Facial sensation to light touch and pinprick was normal. On testing of
corneal reflexes, the left eye did not close when the left cornea was touched but the right
eye closed when either cornea was touched. There was weakness of the left side of the face;
the patient was unable to raise his eyebrow or fully close his left eye; he had only a slight
amount of movement of his left levator labii. Facial function was graded as House-
Brackmann grade 4.1 The gag reflex was intact. However, visualization of the larynx
revealed a left vocal cord paresis, suggesting a lesion of the left vagus nerve. The patient
had normal strength during shoulder shrug and was able to lift his arms over his head.
However, his left sternocleidomastoid muscle appeared to be weak.
The patient had normal strength and muscle tone in the extremities. Romberg’s test
demonstrated increased sway without falls. Gait was within normal limits, although the
patient tended to veer slightly to the left when he made sharp turns.

277
278 VESTIBULAR DISORDERS

On otologic examination, the left pinna, external auditory canal, and eardrum revealed
multiple vesicles in the concha and external ear canal and a few on the eardrum. The left
eardrum appeared to be slightly reddened, but there was no evidence of acute otitis media.
Examination of the oral cavity revealed a number of small vesicles on the left buccal
mucosa. Tuning-fork examination revealed a positive Rinne test bilaterally and a midline
Weber’s test with 512 and 1024 Hz tuning forks.
Neurotologic examination revealed a right-beating jerk nystagmus using infrared gog-
gles. The head thrust was abnormal toward the left. The patient could not stand on a foam
pad with his eyes closed.
Question 2: Based on the results of the physical examination, what is this patient’s most
likely diagnosis?
Answer 2: The presence of vesicles on the auricle and in the mouth is highly
suggestive of an acute viral process, most likely herpes zoster. J. Ramsay Hunt2
described a syndrome consisting of facial paralysis, inner ear disturbances, and
painful herpetiform blisters of the auricle in 1907. The cause of the syndrome has
been confirmed to be herpetic infection involving the seventh and eighth cranial
nerves.3,4 Thus, this patient’s most likely diagnosis is Ramsay Hunt syndrome, also
known as herpes zoster oticus. Facial paralysis is seen in about 60% of patients, and
eighth nerve dysfunction, consisting of either sensorineural hearing loss or vertigo,
appears in about 40% of patients with herpes zoster oticus. Histopathologic studies
have confirmed the direct involvement of the seventh nerve by an inflammatory
process marked by hemorrhage, extravasation of blood, inflammatory cell infiltra-
tion, and ultimately nerve fiber degeneration. It is not known whether this effect is
the result of an autoimmune phenomenon or of the viral infection itself. The
histopathologic correlate of the eighth nerve disturbance has not been elucidated.
Some patients, like this one, have a more widely distributed cranial neuropathy that
can affect the tenth and eleventh cranial nerves.

Laboratory Testing

Videonystagmography: Ocular motor testing revealed a right-beating spontaneous vestib-

ular nystagmus. Caloric testing revealed absent bithermal responses on the left and normal
responses on the right. The patient refused ice-water testing.
Rotational testing revealed a mild right directional preponderance.
Posturography indicated excessive sway with falls on conditions 5 and 6, that is, a
vestibular pattern.
An audiogram showed a high-frequency sensorineural hearing loss in the left ear; the
word recognition score was 80% in the left ear. The right ear was normal.
VEMPs were normal on the right and absent on the left.
An MRI scan of the head showed enhancement of the seventh and eighth cranial nerves
within the internal auditory canal suggestive of an inflammatory neuritis (Case 41:
Figure 1). No mass lesions or other abnormalities were noted.
Question 3: How do the laboratory tests help to localize the site of viral involvement?
Answer 3: The abnormal audiogram, loss of caloric function in the left ear, and
absent VEMP on the left suggest involvement of both the vestibular and cochlear
subdivisions of the inner ear or eighth cranial nerve on the left. The MRI demon-
strated inflammatory cranial neuritis, which may be of viral origin.5
 CASE 41: RAMSAY HUNT SYNDROME 279

Case 41: Figure 1 Axial magnetic resonance image of the head showing enhancement of the seventh and
eighth cranial nerves within the internal auditory canal suggestive of an inflammatory neuritis. White
arrow5vestibular cochlear nerve bundle within the internal auditory canal.
Source: With permission fromHirschBEetal: Localizing retrocochlear hearing loss. AmJ Otol 17(4):537–546,1996.11

Question 4: Can viruses other than herpes zoster or nonviral infectious agents cause
neuritis leading to hearing loss or vestibular system disturbances?
Answer 4: Several other viruses can cause hearing loss or vestibular disturbance,
including rubella, rabies, mumps, cytomegalic viruses, and human immunodefi-
ciency virus (HIV). In addition to the viral causes of neuritis, several bacterial infec-
tions can also produce inner ear disturbances, including Lyme disease, syphilis,
tetanus, typhoid fever, leptospirosis, and diphtheria.
Question 5: Can Lyme disease cause both facial nerve paralysis and inner ear disturbances?
Answer 5: Lyme disease, a systemic spirochetal (Borrelia burgdorferi) infection that
follows the bite of an infected tick (Ixodes dammini), should be considered as a
possible cause of any inflammatory polyneuritis.6 Lyme disease is well known to
cause facial paralysis, but it may also cause decreased hearing, tinnitus,
and vertigo.7
During the first stage of Lyme disease, erythema chronicum migrans, character-
ized by a small expanding papula that forms an annular lesion with a central clear
zone and an erythematous outer border, is reported in 60% to 80% of patients.
During stage 2 Lyme disease, about 15% to 20% of patients develop neurologic
complications. Although facial paralysis is one of the most common neurologic
signs, both hearing loss and vertigo are common. Krejcova et al.7 reported that
44% of their patients had hearing abnormalities and 81% had vestibular abnorm-
alities.

Diagnosis/Differential Diagnosis

This patient was given the diagnosis of Ramsay Hunt syndrome, that is, herpes zoster oticus.
280 VESTIBULAR DISORDERS

Treatment/Management

This patient was treated with a combination of acyclovir, 4 g daily in divided doses, and
prednisone, 1 mg/kg per day for 10 days.8,9,10 Phenergan, 25 to 50 mg intramuscularly, was
needed for 2 days to control nausea and vomiting. Ophthalmic ointments were prescribed
because of exposure of the left cornea as a result of the facial paralysis. The skin lesions of
the auricle were treated with mupirocin ointment. There was no apparent secondary
infection of the skin by staphylococcal or streptococcal bacteria, so no systemic antibiotic
therapy was needed.
The patient was followed closely over the ensuing 2 weeks. No further progression of
the cranial nerve deficits or significant side effects from the medications occurred. The ear
pain and vesicles on the ear resolved within 2 weeks. Facial movement returned to nearly
normal within 3 months. The tenth and eleventh cranial nerve abnormalities recovered
completely. The patient reported the continued presence of mild disequilibrium, hearing
impairment, and unilateral left-sided tinnitus at 6-month follow-up.

Summary

A 55-year-old man presented with ear pain, hearing loss, vertigo, and progressive facial
paralysis. Physical examination suggested the diagnosis of a polyneuritis with involvement
of cranial nerves 7, 8, 10, and 11. A vesicular eruption of the pinna along with facial
paralysis and audiovestibular symptoms suggested Ramsay Hunt syndrome. Treatment
consisted of acyclovir, steroids, skin care, eye care, and vestibular-suppressant medica-
tions. The patient recovered nearly completely, with only residual mild dizziness, hearing
impairment, and tinnitus.

Teaching Points

1. Ramsay Hunt syndrome consists of facial paralysis, inner ear disturbances, and
painful herpetiform blisters of the auricle. The cause of the syndrome has been
confirmed to be herpetic infection involving the seventh and eighth cranial nerves.
Occasionally, viral involvement of other cranial nerves also occurs.
2. Viruses other than herpes zoster can cause hearing loss and vestibular system
disturbances. These viruses include rubella, rabies, mumps, cytomegalic viruses, and HIV.
3. Inflammatory cranial neuritis may be demonstrated on MRI.
4. The treatment of Ramsay Hunt syndrome includes acyclovir, 4 g daily in divided
doses, and prednisone, 1 mg/kg per day for 10 days. Vestibular suppressants may be
required for nausea and vomiting. Ophthalmic ointments may be needed if exposure of
the cornea occurs as a result of the facial paralysis. The skin lesions of the auricle can be
treated with medicated ointments. Secondary infection of the skin by staphylococcal or
streptococcal bacteria can occur in severe cases and should be treated appropriately.
5. Bacterial infection also may produce inner ear disturbances. Examples include
Lyme disease, syphilis, tetanus, typhoid fever, leptospirosis, and diphtheria. In
particular, Lyme disease causes both facial nerve paralysis and inner ear disturbances.
Lyme disease is caused by a systemic spirochetal (B. burgdorferi) infection that follows
the bite of an infected tick (I. dammini) and should be considered as a possible cause of
any inflammatory polyneuritis.
 CASE 41: RAMSAY HUNT SYNDROME 281

References
1. House JW, Brackmann DE: Facial nerve grading system. Otolaryngol Head Neck Surg
93:146–147, 1985.
2. Hunt JR: Herpetic inflammations of the geniculate ganglion: A new syndrome and its aural
complications. Arch Otol 36:371–381, 1907.
3. Weller TH: Varicella and herpes zoster: Changing concepts of the natural history, control, and
importance of a not-so-benign virus. N Engl J Med 309:1434–1440, 1983.
4. Wackym PA: Molecular temporal bone pathology: II. Ramsay Hunt syndrome (herpes zoster
oticus). Laryngoscope 107(9):1165–1175, 1997.
5. Korzec K, Sobol SM, Kubal W, Mester SJ, Winzelberg G, May M: Gadolinium-enhanced
magnetic resonance imaging of the facial nerve in herpes zoster oticus and Bell’s palsy:
Clinical implication. Am J Otol 12:163–168, 1991.
6. Moscatello AL, Worden DL, Nadelman RB, Wormser G, Lucente F: Otolaryngologic aspects
of Lyme disease. Laryngoscope 101:592–595, 1991.
7. Krejcova H, Bojar M, Jerabek J, Thomas J, Jirous J: Otoneurological symptomatology in
Lyme disease. Adv Otorhinolaryngol 42:210–212, 1988.
8. Dickins JRE, Smith JT, Graham SS: Herpes zoster oticus: Treatment with intravenous
acyclovir. Laryngoscope 98:776–779, 1988.
9. Murakami S, Hato N, Horiuchi J, Honda N, Gyo K, Yanagihara N: Treatment of Ramsay Hunt
syndrome with acyclovir-prednisone: Significance of early diagnosis and treatment. Ann
Neurol 41(3):353–357, 1997.
10. Porter S: Do antiviral agents effectively treat Ramsay Hunt syndrome? Evid Based Dent
9(4):116, 2008.
11. Hirsch BE, Durrant JD, Yetiser S, Kamerer DB, Martin WH: Localizing retrocochlear hearing
loss. Am J Otol 17(4):537–546, 1996.
CASE 42
Meniere’s Disease—Ablative
Management of the
Medically Refractory Patient

History

A 50-year-old woman who worked as a cashier in a large grocery store presented with a
complaint of recurrent bouts of vertigo that had started 7 years ago but worsened during the
6 months prior to evaluation with severe vertigo occurring every 7–14 days. The spells
consisted of severe rotatory vertigo, nausea, and often retching or vomiting that usually
lasted for a few hours. For 1 or 2 days after the acute vertigo, she felt somewhat unsteady
and dizzy when moving her head. Subsequently, her symptoms resolved within several
days. The episodes of vertigo occurred irregularly and without an obvious precipitant. She
reported being quite embarrassed on a number of occasions when incapacitating vertigo
occurred suddenly at work. Several years ago, the patient had suffered a few spells of
vertigo and was evaluated by her primary care physician, who thought that the vertigo
might possibly be caused by Meniere’s disease. The primary care physician prescribed
meclizine and a diuretic, with a low-salt diet. The patient had faithfully used the diuretic
and restricted salt intake and was symptom free until about 6 months ago. She felt quite
frustrated by the return of episodic vertigo.
In addition to the episodes of vertigo, the patient reported the recent onset of some
hearing disturbances in her right ear. She described her hearing as sometimes muffled or
clogged with intermittent tinnitus, and fullness in her right ear before the vertigo. On the
day of evaluation, the patient noticed that loud noises sounded abnormally sharp and
almost painful.

Physical Examination

The neurologic examination was normal except that the patient had increased sway on
Romberg’s test. Gait was slightly wide based. Otologic examination was normal. Pressure
changes induced in the external auditory canal by pneumatic otoscopy produced no
dizziness or nystagmus. Neurotologic examination revealed no spontaneous nystagmus,
an abnormal head thrust test with brisk head movement to the right, normal Dix-Hallpike
tests, and normal stability on foam with eyes open and closed.

282
 CASE 42: MENIERE’S DISEASE-ABLATIVE MANAGEMENT 283

Laboratory Testing

Videonystagmography: Ocular motor function including saccades, pursuit, and optokinetic

nystagmus was normal. A low-amplitude left-beating spontaneous vestibular nystagmus
was noted. There was no positional nystagmus. Caloric irrigation revealed a significant
(>50%) right-reduced vestibular response.
Rotational testing revealed normal gain and phase with a mild left directional prepon-
derance.
Posturography was normal.
Audiometric testing showed normal hearing in the left ear and a moderate
low-frequency sensorineural hearing loss in the right ear. Word recognition scores were
88% on the right and 100% on the left.
An MRI scan of the brain with and without gadolinium enhancement was normal.

Diagnosis/Differential Diagnosis

The patient was diagnosed with right unilateral Meniere’s disease. She was treated with a
2-week course of oral Prednisone (1mg/kg/day) and was re-started on combined salt restriction
and hydrochlorothiazide plus triameterene. After several months of continued complaints, the
patient was treated with a series of intratympanic steroid injections. Unfortunately, the patient
remained symptomatic with episodic vertigo despite these measures.
Question 1: What treatment options are available for patients who have failed both medical
and nonablative surgical management?
Answer 1: The treatment options include ablative procedures such as chemical
labyrinthectomy, vestibular nerve section, and surgical labyrinthectomy. The goal
of these procedures is to permanently ablate vestibular function in the ear affected
by Meniere’s disease. The dysfunctional ear can then no longer produce vertigo
because the vestibular apparatus has lost hair cells (chemical labyrinthectomy, been
destroyed (labyrinthectomy) or disconnected from the brain (vestibular nerve sec-
tion). Ablative surgical procedures significantly reduce the frequency and severity of
vertigo compared to the natural history of Meniere’s disease.1
In chemical labyrinthectomy, an ototoxic medication that is preferentially toxic
to vestibular as compared to auditory hair cells, such as gentamicin, is injected into
the middle ear space (Case 42: Figure 1).2 Once in the middle ear, the medication
reaches the inner ear through the round window membrane and exerts a toxic
effect on the vestibular hair cells, resulting in ablation of vestibular function in the
ear. Chemical labyrinthectomy is performed in the office setting using topical
anesthesia. Treatment protocols are not standardized and vary from single injec-
tions to ‘‘alter’’ vestibular function,3 variable number of injections titrated to vertigo
control,4 and larger fixed doses aimed at complete ablation.5 A meta-analysis
suggested better vertigo control rates with titration compared to single dose regi-
mens.6 Vertigo control using chemical labyrinthectomy (estimated 80% complete
control and 96% substantial and complete control) appears to be slightly lower
than that achieved using vestibular nerve section.7 Hearing loss induced by chemi-
cal labyrinthectomy occurs in about 20% of patients compared to about 5% of
patients following vestibular nerve section. It is unclear, however, if the long-term
hearing results differ among patients undergoing vestibular neurectomy, chemical
284 VESTIBULAR DISORDERS

Case 42: Figure 1 Three-dimensional computer-aided reconstruction of the vestibular aqueduct

and endolymphatic sac anatomically positioned within a microdissected left human temporal
bone. VA5vestibular aqueduct; EAVA5external aperture of the vestibular aqueduct; FC5facial
canal; EACA5external aperture of the cochlear aqueduct; IACA5internal aperture of the
cochlear aqueduct; IAP5internal auditory canal; JF5jugular foramen; PSCC5posterior
semicircular canal; SS5sigmoid sinus; SSCC5superior semicircular canal.
Source: With permission from Wackym PA et al: Re-evaluation of the role of the human endolymphatic sac
in Meniere’s disease. Otolaryngol Head Neck Surg 102:732–744, 1990. 11

labyrinthectomy, and the natural progression of hearing loss that characterizes

Meniere’s disease.
Vestibular nerve section is also highly successful (85% to 95% complete vertigo
control) and has the advantage that hearing is usually preserved in the operated ear.8,9
Vestibular nerve section is illustrated in Case 42: Figure 2. The disadvantage of vestibular
nerve section is that it is a more complicated and technically demanding procedure.
Although the incidence of complications is low, 1–3 days of hospitalization following
surgery is required and prolonged time (4–6 weeks) away from work is typical.
Labyrinthectomy is a highly successful procedure (90% to 95% vertigo control) and has
a relatively low risk but always results in permanent loss of hearing in the treated ear.10
Surgical labyrinthectomy is illustrated in Case 42: Figure 3. The advantages of labyr-
inthectomy include brief operating time, technical ease, and the ability to visualize clearly
and remove all vestibular neuroepithelium, which ensures the reliable control of vertigo.
Question 2: What laboratory testing is indicated before surgery for Meniere’s disease?
Answer 2: Vestibular function testing is indicated to search for evidence of coexisting
central nervous system dysfunction and to assess function in both the affected and
unaffected ears. Central nervous system dysfunction is a contraindication to surgery
because of its potential adverse effect on post-surgical vestibular compensation,
which is required for a successful clinical outcome. Also, it is helpful to know
whether the contralateral ear has normal caloric function. Moreover, the degree
of caloric weakness in the affected ear can be used to estimate the severity of the
post-surgical acute vestibular syndrome. If the ear to be operated on has absent
responses preoperatively, the patient’s immediate postoperative vestibular imbal-
ance may be mild because the patient probably already has compensated for a
unilateral vestibular deficit.
(a) (b)

(c)

Case 42: Figure 2 (A) Gross anatomic view of the semicircular canals from a microdissected
right human temporal bone. (B) Surgical labyrinthectomy performed by opening each of the
canals and the vestibule, with direct visualization and removal of the neuroepithelium. Curved
arrow5 superior semicircular canal; open arrow5horizontal semicircular canal; straight
arrow5posterior semicircular canal; double arrows5facial nerve; white arrow5vestibule.

(a) (b)

Case 42: Figure 3 (A) Surgical view of the vestibular and cochlear nerves through a small
craniotomy posterior to the left mastoid. (B) Selective vestibular nerve section is performed
using micro-scissors. Note the small blood vessel running on the posterior surface of the
vestibular-cochlear nerve complex, which helps to define the plane between the vestibular and
cochlear nerve bundles. (C) Completed vestibular nerve section. Open arrow5cerebellar
flocculus; curved arrow5cochlear division of the eight cranial nerve; double black
arrows5blood vessel demarcating the border between the cochlear and vestibular divisions of
the eighth cranial nerve; white arrow5fifth cranial nerve; arrowhead5strand of arachnoid tissue.

285
286 VESTIBULAR DISORDERS

An audiogram is indicated to (1) confirm the involved ear and to be sure it fits into a
Meniere-type pattern, (2) to document the amount and usefulness of the remaining
hearing to the patient because, as noted above, this information is an important factor
in deciding which surgical procedure to consider, and (3) to assess whether the con-
tralateral ear is also affected by endolymphatic hydrops. Brain imaging is also indicated
in all patients before surgical intervention to assess the central nervous system.

Question 3: What criteria should be met before considering ablative surgical treatments?
Answer 3: As a general rule, the following three criteria should be met before
considering ablative surgery for vertigo. First, the vertigo should be caused by
unilateral peripheral vestibular dysfunction and the offending ear must be localized
with certainty. Meniere’s disease is one of the most common forms of unilateral
peripheral vestibular dysfunction, and the affected side is usually unambiguously
identified by the presence of unilateral hearing loss, tinnitus, and aural fullness.
Second, the vertigo should be disabling to the patient. There are no hard-and-fast
rules to determine disability, and each patient’s situation and desires must be
considered individually. Third, there should be no signs or symptoms of central
vestibular system dysfunction that could impair vestibular compensation (see
Chapter 1 and Cases 1 and 3).11,12 Central nervous system dysfunction can be
detected by the neurologic portion of the physical examination and confirmed by
vestibular function testing. Aging also adversely affects vestibular compensation,
and therefore the patient’s age, both chronologic and physiologic, must be con-
sidered before recommending surgery.
In the setting of bilateral Meniere’s disease (see Case 29) or in the setting of
unilateral Meniere’s disease complicated by a contralateral hearing loss of any
cause, treatment decisions regarding surgical treatment can be complex and abla-
tive treatments are generally avoided.

Question 4: At what stage in a patient’s clinical course should surgery be considered for
Meniere’s disease?
Answer 4: Ablative surgical candidates should have failed at least a 6-month trial of
medical therapy (diuretic and dietary salt restriction), nonablative interventions
should have been considered or attempted, and the vertigo should be disabling
to the patient. Vertigo caused by Meniere’s disease is usually incapacitating, produ-
cing violent spinning vertigo, loss of postural control, nausea, and often vomiting.
These episodes usually last a few hours, and most patients need to rest or sleep
afterward. When these episodes are frequent, employment, family life, and perso-
nal well-being are threatened and surgical intervention is appropriate. As noted
above, the Meniere’s disease should not be bilateral and there should be no
evidence of central nervous system dysfunction. Younger individuals with financial
and family responsibilities are more likely to feel disabled by the recurrent vertigo
and often seek a surgical remedy earlier in their disease than nonworking or retired
individuals, who can usually tolerate this condition without much disruption of their
lifestyle. Thus, because Meniere’s disease is not a life-threatening disorder, surgical
intervention should be emphasized only when vertigo is causing a significant and
unacceptable change in a patient’s lifestyle.

Question 5: Which ablative treatment is best?

Answer 5: Treatment decisions are always individualized as there are pros and cons
to each procedure. Our policy is to present all procedures to patients so they can
 CASE 42: MENIERE’S DISEASE-ABLATIVE MANAGEMENT 287

have an opportunity to make an informed choice for what is best for their own
particular circumstances.
Our general view is that procedures that can potentially preserve hearing should
be considered first. This view recognizes that (1) hearing in Meniere’s disease
typically fluctuates over time and could improve spontaneously after surgery;
(2) individuals with many years of life expectancy have a chance of unexpectedly
losing hearing in their contralateral ear. If this should happen, any hearing that is
preserved may be of critical importance; and (3) speech reception threshold and
word recognition levels do not fully describe all the beneficial aspects of hearing.
‘‘Useful’’ hearing is difficult to define and must be individualized.
Thus, patients with profound loss of hearing are ideal candidates for surgical or
chemical labyrinthectomy. Patients with normal or nearly normal hearing are ideal
candidates for vestibular nerve section (hearing loss risk 5%) and good candidates
for chemical labyrinthectomy (hearing loss risk 20%). Due to increasing risks of
intracranial surgery in older patients, patients over age 65 are generally better
candidates for surgical or chemical labyrinthectomy.

Treatment/Management

The patient elected to undergo right selective vestibular nerve section. The surgical
procedure was performed without complication and required approximately 3 hours.
After surgery, the patient remained in the hospital for 4 days. On the first postoperative
day, the patient was very nauseated and vomited when she rolled over in bed. She stayed in
bed the entire day and required intravenous hydration and intramuscular anti-emetics.
Interestingly, she stated that an acute Meniere attack was worse than the way she felt after
surgery. Third-degree left-beating vestibular nystagmus, that is, a horizontal-torsional left-
beating vestibular nystagmus that was present in all fields of gaze but worst on leftward
gaze was noted. On the second postoperative day, she was able to get out of bed, ambulate
with assistance, and drink fluids without vomiting. Her gait was wide based and slow. She
consistently veered to the right and restricted head movement. Examination of her extrao-
cular movements revealed the presence of second-degree vestibular nystagmus, that is, a
nystagmus that was like the third-degree nystagmus seen the previous day except that now
the nystagmus was present only with the gaze straight ahead and to the left. There was no
nystagmus on rightward gaze. Consultation with a physical therapist was obtained and the
patient was instructed regarding the use of head, eye, and body exercises to promote
vestibular compensation (see Chapter 6). The patient was discharged home on the fourth
postoperative day. On the day of discharge, a first-degree vestibular nystagmus was noted,
that is, a nystagmus that was present only on gaze to the left but absent on rightward or
straight-ahead gaze. The patient was able to return to work about 1 month later.

Summary

A 50-year-old woman presented with a 1-year history of recurrent vertigo. She was
diagnosed as having unilateral Meniere’s disease. Medical therapy, which was successful
initially, was subsequently unsuccessful. She was treated with intratympanic steroid
injections which was unsuccessful. She then underwent surgery consisting of a selective
vestibular nerve section. Her hearing was unchanged. Vertiginous episodes ceased. The
288 VESTIBULAR DISORDERS

patient underwent vestibular rehabilitation with a physical therapist and returned to work 1
month following surgery.

Teaching Points

1. Ablative treatment for Meniere’s disease includes vestibular nerve section,

chemical labyrinthectomy, and surgical labyrinthectomy. It is essential that the
patient understand that none of these procedures benefit the hearing loss, tinnitus, or
aural fullness associated with Meniere’s disease. Candidates should have failed at least
a 6-month trial of medical therapy (diuretic and dietary salt restriction), have considered
other nonablative treatments, and the vertigo should be disabling to the patient.
2. Chemical labyrinthectomy is able to produce ablation of vestibular function
without surgery or general anesthesia. This procedure consists of instillation of an
ototoxic agent, typically an aminoglycoside antibiotic, into the middle ear. Effective
vertigo control can be achieved in up to 96% of patients. Chemical labyrinthectomy is
especially applicable to elderly or infirm patients with disabling vertigo.
3. Vestibular function testing in Meniere’s disease may uncover coexisting central
nervous system dysfunction. Central nervous system dysfunction is a contraindication
to surgery because of its potential adverse effect on postsurgical vestibular
compensation, which is required for a successful clinical outcome.
4. Ablative procedures are generally avoided in cases of bilateral Meniere’s disease.
In this situation it can be difficult to firmly establish the offending ear and surgically
induced loss of vestibular function can result in disabling oscillopsia and ataxia. Thus,
nonablative approaches are preferred.

References
1. Silverstein, H, Smouha, E, Jones, R: Natural history vs. surgery for Meniere’s disease.
Otolaryngol Head Neck Surg 100:6–16, 1989.
2. Monsell, EM, Cass, SP, Rybak, LP: Chemical labyrinthectomy: Methods and results. In
Brackmann DE (ed). Otologic Surgery. Philadelphia: WB Saunders, 1994.
3. Harner SG, Driscoll CL, Facer GW, Beatty CW, McDonald TJ: Long-term follow-up of
transtympanic gentamicin for Ménière’s syndrome. Otol Neurotol 22(2):210–214, 2001.
4. Atlas J, Parnes LS: Intratympanic gentamicin for intractable Meniere’s disease: 5-year
follow-up. J Otolaryngol 32(5):288–293, 2003.
5. Hone SW, Nedzelski J, Chen J: Does intratympanic gentamicin treatment for Meniere’s
disease cause complete vestibular ablation? J Otolaryngol 29(2):83–87, 2000.
6. Chia SH, Gamst AC, Anderson JP, Harris JP: Intratympanic gentamicin therapy for Ménière’s
disease: A meta-analysis. Otol Neurotol 25(4):544–552, 2004.
7. Hillman TA, Chen DA, Arriaga MA: Vestibular nerve section versus intratympanic genta-
micin for Meniere’s disease. Laryngoscope 114(2):216–222, 2004.
8. Monsell, EM, Wiet RJ, Young NM, Kazan RP: Surgical treatment of vertigo with retro-
labyrinthine vestibular neurectomy. Laryngoscope 98:835–839, 1988.
9. Tewary AK, Riley N, Kerr AG: Long-term results of vestibular nerve section. J Laryngol Otol
112(12):1150–1153, 1998.
10. Kemink, JL, Telian SA, Graham MD, Joynt L: Transmatoid labyrinthectomy: Reliable
surgical management of vertigo. Otolaryngol Head Neck Surg 101:5–10, 1989.
11. Konrad, HR: Intractable vertigo—When not to operate. Otolaryngol Head Neck Surg
95:482–484, 1986.
12. Monsell, EM, Brackmann, DE, Linthicum, FH: Why do vestibular destructive procedures
sometimes fail? Otolaryngol Head Neck Surg 99:472–479, 1988.
Case 43
Chronic Otitis Media

History

A 45-year-old male insurance agent presented with 1 week of disequilibrium. The patient’s
disequilibrium began following a vertiginous episode that lasted for 1 day and was
associated with nausea and vomiting. The patient volunteered that his vertigo spell
occurred 3 days following the onset of a malodorous discharge and pain in his left ear.
Since resolution of the acute spell of vertigo, the patient had had disequilibrium that varied
in intensity. He noted occasional staggering but otherwise was only mildly unsteady. The
patient did not complain of any positional symptoms but felt mildly lightheaded and dizzy
even at rest. In addition, he reported that recently he could provoke brief vertigo by putting
his finger in his left ear to relieve itching. He also occasionally noticed momentary vertigo
when he heard a loud sound. The patient reported a lifelong history of recurrent ear
infections and had undergone mastoid surgery on the left ear at age 10 years. Medicated
ear drops were prescribed for him by his primary care physician before evaluation.
Question 1: Based on the patient’s history, what are the diagnostic considerations?
Answer 1: The history of chronic ear infections and the occurrence of a malodorous
discharge immediately preceding the onset of vertigo suggest that the patient’s
vertigo may be related to infection involving the middle ear and mastoid.
Considering his long history of middle ear problems, the patient may simply be
experiencing an acute exacerbation of chronic otitis media, or there may be an
ongoing chronic middle ear infection related to recurrent cholesteatoma (see later in
this case discussion). Alternatively, the patient’s complaints may have no relationship
whatever to past and present middle or outer ear problems. If so, the differential
diagnosis is broad.
Question 2: What is a cholesteatoma of the ear?
Answer 2: A cholesteatoma of the ear is a skin cyst that behaves like a localized tumor
(Case 43: Figure 1). It causes destruction of bone and predisposes to repeated acute
middle ear and mastoid infections. Cholesteatoma of the ear is usually found in the
presence of chronic middle ear infection (chronic otitis media).
Question 3: How do chronic otitis media and cholesteatoma cause vertigo?
Answer 3: An acute exacerbation of chronic otitis media can cause vertigo and
dizziness as a result of bacterial toxins contained in the inflammatory exudate of

289
290 VESTIBULAR DISORDERS

Case 43: Figure 1 Schematic drawing of the ear drum, cholesteatoma within the middle ear
space, and the inner ear. The cholesteatoma is shown causing erosion of the lateral semicircular
canal, resulting in a bony fistula.
Source: Modified with permission from Glasscock ME et al: Handbook of Vertigo. New York: Raven Press,
1990. 8

the middle ear reaching the vestibular labyrinth, usually by transmission through
the round window membrane. This process is referred to as serous labyrinthitis and
also may be associated with sensorineural hearing loss primarily affecting the high
frequencies. Cholesteatoma of the ear may cause dizziness by creating a perilym-
phatic fistula as a result of erosion of the bony vestibular labyrinth (Case 43:
Figure 1). The combination of an erosive perilymphatic fistula and otitis media
can cause both serous labyrinthitis and bacterial labyrinthitis.1–4
Question 4: How can an acute exacerbation of chronic otitis media be distinguished from a
cholesteatoma of the ear?
Answer 4: Chronic otitis media and cholesteatoma of the ear cannot be distin-
guished on the basis of the history. Diagnosis of a cholesteatoma of the ear can
be made by debridement of the external ear followed by an otologic examination
using an operative microscope by a physician skilled in the management of otologic
disease. If a cholesteatoma is found, CT imaging is indicated to aid in evaluating the
bony labyrinth for erosion and fistula formation. Imaging studies are not indicated
before cleaning and examining the ear.

Physical Examination

The patient’s general and neurologic examinations were normal, including a negative
Romberg’s test aside from mildly unsteady gait. He was able to stand on compliant foam
with his eyes open but not with his eyes closed, indicating an ongoing vestibular system
abnormality. Compression of the tragus on the left produced both nystagmus and a
sensation of vertigo. Otologic examination revealed a malodorous yellow discharge drain-
ing from the left ear, a tympanic membrane perforation, and thickened polypoid mucosa in
the middle ear space. With the operative microscope, the ear was cleaned using suction and
debrided to reveal minimal bony erosion of the external auditory canal wall and a large
cholesteatoma pocket with a moist cholesteatoma matrix overlying the area of the lateral
semicircular canal. On tuning fork examination, the Weber’s test showed lateralization to
the right. The Rinne test was normal on the right, and could not be performed on the left.
 CASE 43: CHRONIC OTITIS MEDIA 291

Question 5: What do the results of the physical examination suggest about the cause of this
patient’s vertigo?
Answer 5: The presence of a large cholesteatoma with active inflammation
overlying the lateral semicircular canal suggests that the patient’s vertigo
may be caused by the presence of fistulization of the lateral semicircular canal.
The vertigo and nystagmus induced by pressure changes in the external
auditory canal using pneumatic otoscopy or tragal pressure are known as
Hennebert’s symptoms and signs and are highly suggestive of bony labyrinthine
fistula. The tuning fork tests suggest a profound sensorineural hearing loss in
the left ear.
Question 6: What is the value of vestibular laboratory testing at this point in the evaluation
of this patient?
Answer 6: The presence of a cholesteatoma and a positive Hennebert’s sign strongly
suggest that a bony fistula in the left ear is the source of the patient’s vestibular
symptoms. The profound sensorineural hearing loss in the left ear further suggests
that the fistula has produced both auditory and vestibular damage. Caloric testing
can provide information regarding responsiveness of the vestibular labyrinth, and in
a patient presenting with dizziness and a history of chronic ear disease, abnormal
caloric function is frequently found.5 However, in this case vestibular laboratory
testing is not indicated because of the presence of the severe acute infection. Also,
vestibular testing in the setting of an acute middle ear infection is very uncomfor-
table and does not provide further significant information needed for diagnosis at
this time.
Question 7: What is the value of obtaining a CT scan at this point in the patient’s
evaluation? What is the value of MRI?
Answer 7: A high-resolution CT scan of the temporal bone can define the bony
architecture of the vestibular labyrinth and mastoid and can confirm the
presence of a bony labyrinthine fistula. In addition, other potentially life-
threatening conditions such as a sigmoid sinus thrombosis or a dural abscess
may be detected. A CT scan is indicated rather than MRI because of the ability
of CT to image the bony anatomy of the labyrinth; MRI of the temporal bone
could reveal widespread inflammation but could not provide the anatomic
detail necessary to confirm the diagnosis of a bony labyrinthine fistula. MRI
is indicated if there is any signs or symptoms suggesting intracranial involve-
ment of the otologic disease, in particular, pain or headache out of proportion
to the visable disease.

Laboratory Testing

Vestibular laboratory function testing was deferred because of the presence of acute
infection and discharge.
Audiometric testing showed normal hearing in the right ear but profound sensorineural
hearing loss in the left ear.
A CT scan of the temporal bones showed soft tissue densities and widespread bone
destruction consistent with cholesteatoma and confirmed the presence of a bony fistula of
the horizontal semicircular canal.
292 VESTIBULAR DISORDERS

Diagnosis/Differential Diagnosis

The patient was given the diagnosis of chronic otitis media with cholesteatoma formation
and a fistula of the horizontal semicircular canal.

Treatment/Management

Following debridement of the ear, the patient was placed on an oral antibiotic and medicated
otic drops. He was asked to return in 1 week for further debridement and examination.
The patient returned in 1 week with significant improvement in his symptoms. The
drainage had greatly diminished, and the dizziness had been reduced but had not disap-
peared completely. Otologic examination revealed significant improvement in the amount
of discharge and inflammation present in the middle ear and mastoid space, which was
visible because of the previous surgery at age 10. The patient’s medications were changed
from medicated otic drops to daily boric acid irrigation of the ear. He was counseled about
the need for future revision mastoid surgery, which was performed.
Question 8: What constitutes surgery for cholesteatoma? When is surgery indicated for a
patient who presents with vertigo and is found to have otitis media and a cholesteatoma?
Should this patient be advised to undergo repeat mastoid surgery?
Answer 8: Surgery for cholesteatoma consists of opening the mastoid cavity and
excising the cholesteatoma or widely exteriorizing the cholesteatoma skin cyst.6
Bony fistula of a semicircular canal must be correctly identified by the surgeon
because careless exposure of the fistula can cause further deterioration of hearing
and vestibular symptoms. Once identified, it can be managed in one of two ways,
either removal of the cholesteatoma with fistula repair or exteriorization of the
cholesteatoma; the skin covering the fistula can be carefully removed and the fistula
repaired with bone pâte and fascia.7 Alternatively, the active cholesteatoma can be
exteriorized; and by preventing the further progression and inflammation asso-
ciated with the cholesteatoma, further acute vertiginous symptoms are usually
eliminated. Unfortunately, in this case there is no treatment for the hearing loss,
which is permanent.
Surgery is indicated for a patient with a cholesteatoma that is not self-
cleaning, that is, that produces repeated acute infections, or that is associated
with complications such as vertigo, hearing loss, facial nerve paralysis, or
central nervous system complications such as meningitis, dural venous sinus
thrombosis, or a dural abscess. In this patient’s case, there is a large choles-
teatoma that has produced a bony labyrinthine fistula with concomitant hear-
ing loss and vertigo. If this cholesteatoma is treated only medically, it is likely
that the patient will undergo additional repeated acute attacks of vertigo,
suffer persistent imbalance, and be at risk for central nervous system compli-
cations of bacterial infection.
Question 9: What is the proper treatment of patients with chronic otitis media that is not
associated with cholesteatoma?
Answer 9: Acute exacerbations of chronic otitis media are treated primarily with
frequent debridement, local antibiotics, and oral antibiotics. Occasionally, tympa-
noplasty and mastoid surgery are required, but only after the failure of local care.
 CASE 43: CHRONIC OTITIS MEDIA 293

Summary

A 45-year-old man with a previous history of chronic ear disease and mastoid surgery at
age 10 years presented with disequilibrium following the onset of acute vertigo after 3 days
of a malodorous discharge from his left ear. The patient’s ear was debrided, revealing the
presence of a cholesteatoma. He had a positive Hennebert’s sign and a profound loss of
hearing in the left ear, suggesting the presence of a bony labyrinthine fistula. A fistula of the
horizontal semicircular canal was confirmed by CT imaging. Treatment consisted of
repeated debridement and ototopic agents followed by a revision mastoidectomy.

Teaching Points

1. Acute otitis media or an acute exacerbation of chronic otitis media can cause
vertigo and dizziness as a result of bacterial toxins contained in the middle ear
inflammatory exudate reaching the vestibular labyrinth, usually by transmission
through the round window membrane. This process is referred to as serous
labyrinthitis and may also be associated with sensorineural hearing loss primarily
affecting the high frequencies.
2. A cholesteatoma of the ear is a skin cyst that behaves like a localized tumor. It
causes destruction of bone and leads to repeated chronic middle ear and mastoid
infections. Cholesteatoma of the ear is often found in the presence of chronic middle ear
infection and can cause dizziness by creating a perilymphatic fistula as a result of
erosion of the bony vestibular labyrinth. The combination of an erosive perilymphatic
fistula and otitis media can cause both serous labyrinthitis and bacterial labyrinthitis.
3. A bony labyrinthine fistula should be considered in a patient with a history of
chronic otitis media who presents with Hennebert’s symptoms and signs, that is,
vertigo and nystagmus induced by pressure changes in the external auditory canal.
A high-resolution CT scan of the temporal bone can define the bony architecture of the
vestibular labyrinth and mastoid and should be used to confirm the presence of a bony
labyrinthine fistula. An MRI scan of the temporal bone can reveal inflammation within
the mastoid but cannot provide the anatomic detail necessary to confirm the diagnosis of
a bony labyrinthine fistula. MRI imaging is indicated if signs or symptoms suggesting
intracranial involvement are present.
4. Treatment of vertigo caused by acute otitis media in an otherwise normal ear
includes drainage and both topical and oral antibiotics.
5. Treatment of vertigo associated with an acute exacerbation of chronic otitis media
or cholesteatoma requires repeated debridement of the ear, a combination of oral
and topical antibiotics, and CT imaging of the ear. Surgery is indicated for a patient
with a cholesteatoma that is not self-cleaning, that is, that produces repeated acute
infections, or that is associated with complications such as vertigo, hearing loss, facial
nerve paralysis, or central nervous system complications such as meningitis, dural
venous sinus thrombosis, or a dural abscess.

References
1. Paparella M, Sugiura S: The pathology of suppurative labyrinthitis. Ann Otol Rhinol Laryngol
76:554–586, 1967.
2. Walby PA, Barrerra A, Schuknecht HF: Cochlear pathology in chronic suppurative otitis
media. Ann Otol Rhinol Laryngol 103(Suppl):3–19, 1983.
294 VESTIBULAR DISORDERS

3. Meyerhoff WL, Kim CS, Paparella MM: Pathology of chronic otitis media. Ann Otol
87:749–760, 1978.
4. Paparella MM, Morizono T, Le CT, Mancini F, Sipila P, Choo YB, Liden G, Kim CS:
Sensorineural hearing loss in otitis media. Ann Otol Rhinol Laryngol 93:623–629, 1984.
5. Gianoli GJ, Soileau JS: Chronic suppurative otitis media, caloric testing, and rotational chair
testing. Otol Neurotol 29(1):13–15, 2008.
6. Sheehy JL, Brackmann DE, Graham MD: Cholesteatoma surgery: Residual and recurrent
disease. Ann Otol Rhinol Laryngol 86:1–12, 1977.
7. Magliulo G, Celebrine A, Cuiuli G, Parrotto D: Surgical management of the labyrinthine
fistula complicating chronic otitis media with or without cholesteatoma. J Otolaryngol Head
Neck Surg 37(2):143–147, 2008.
8. Glasscock ME, Cueva RA, Thedinger BA: Handbook of Vertigo. New York: Raven Press,
1990.
Case 44
Decompensated Bilateral
Vestibular Loss

History

A 71-year-old man presented with a complaint of oscillopsia and gait instability. The
patient noticed that his balance was especially worse in dimly lit environments and when
walking on uneven surfaces. The patient was bothered by complex visual environments
including grocery stores. The patient had fallen without injury on several occasions.
The patient’s history was significant for an ileostomy 20 years earlier associated with a
severe postoperative infection and a 3-month hospitalization during which he received
intravenous gentamicin. At that time, the patient experienced oscillopsia and gait instabil-
ity that largely resolved. During the past several months, the patient’s symptoms recurred.
Question 1: Based upon the patient’s history, what is the most likely diagnosis?
Answer 1: The patient’s history suggests bilateral peripheral vestibular loss of 20
years’ duration secondary to gentamicin ototoxicity (see Case 4). However, there
has been a recent decline in function for reasons that are uncertain. Diagnostic
considerations include additional peripheral vestibular loss superimposed upon a
prior bilateral reduction, a new central nervous system disorder, or decompensa-
tion from the previously compensated bilateral peripheral vestibular ailment.

Physical Examination

General examination was normal. Neurologic examination revealed full extraocular move-
ments without nystagmus. The remainder of the neurologic examination was normal,
except that the patient had gait ataxia with a widened base. Romberg’s test was negative.
Otoscopic examination was normal. Decreased audibility to finger rub was noted in both
ears. The patient’s visual symptoms could be reproduced by applying a gentle vibratory
motion with the index finger just lateral to the outer canthus of the eye while the opposite
eye was occluded. On neurotologic examination, there was no nystagmus behind infrared
goggles. On head thrust testing, refixation saccades were noted with head movement both
to the right and to the left. During ophthalmoscopic testing of the VOR, the optic disc was
noted to move with the patient’s head movements rather than remain stable in space. The
patient was unable to stand on a compliant foam surface with eyes closed without falling.

295
296 VESTIBULAR DISORDERS

Question 2: Based upon the history and the physical examination, what is the patient’s
likely diagnosis?
Answer 2: This patient is probably suffering from the effects of bilateral vestibular
loss as a result of aminoglycoside ototoxicity (see Case 4). The basis for the patient’s
recent decline in function is uncertain. The physical examination clearly indicates a
reduction in both vestibulo-ocular and vestibulospinal function almost certainly
based upon bilateral peripheral vestibular loss.

Additional History

The patient’s records indicated that he had recently undergone placement of a coronary
artery stent and was using zolpidem 5 mg at bedtime and alprazolam on an as-needed basis.
The patient’s recent exacerbation of dizziness and imbalance occurred following his stent
placement.

Laboratory Testing

Videonystagmography: Ocular motor testing was normal. There was no static positional
nystagmus. Caloric testing revealed absent responses in both ears even to ice-water
irrigation.
Rotational testing revealed markedly reduced responses such that no eye movements
were generated at frequencies below 0.5 Hz and there were only a few beats of nystagmus
following deceleration from a constant velocity rotation of 90 degrees per second.
Posturography indicated excessive sway on conditions 4, 5, and 6, that is, a surface-
dependent pattern. Audiometric testing indicated a mild bilateral asymmetric sensorineural
hearing loss.
VEMPs were absent bilaterally.
An MRI scan of the brain was normal aside from some periventricular white matter
hyperintensities consistent with age.
Question 3: What additional information, if any, does vestibular laboratory testing provide
for diagnosis?
Answer 3: The patient’s laboratory testing indicates bilateral vestibular loss con-
firmed by ice water caloric testing, high intensity rotational testing, and vestibular-
evoked myogenic potentials. Note that despite the absence of response to ice water
caloric testing and absent Vemp responses, rotational testing suggests minimal but
not absent function in at least one ear. Posturography supports the diagnosis by
indicating an inability to control upright balance when forced to rely on vestibular
information. Magnetic resonance imaging does not suggest an active neurologic
process but does suggest the possibility of disequilibrium of aging (see Case 10).
The patient’s history of recovery following his initial exposure to gentamicin sug-
gests that the current presentation represents a decompensation from the pre-
viously compensated state.

Diagnosis/Differential Diagnosis

The patient was given a diagnosis of a decompensated bilateral peripheral vestibular loss.
 CASE 44: DECOMPENSATED BILATERAL VESTIBULAR LOSS 297

Question 5: What treatment modalities are available for this patient?

Answer 5: The patient should of course be advised to avoid further exposure to
ototoxic agents. Balance rehabilitation therapy should be ordered. The patient
should also be advised to avoid vestibular suppressive medications such as mecli-
zine, to discontinue or severely limit his use of benzodiazepine medications such as
alprazolam, and to discontinue or limit his use of zolpidem.

Treatment

The patient discontinued zolpidem and alprazolam and was treated with balance rehabili-
tation therapy. The patient was also advised to see an eye doctor regarding his correction
and to request full-frame rather than progressive lenses. Progressive lenses require patients
to coordinate head and eye position to achieve clear vision. This may be difficult for
patients with bilateral vestibular loss.1

Follow-Up

The patient was seen 2 months later. He had discontinued driving and was now using a
cane. He indicated that this oscillopsia persisted and that he had adapted to his bilateral
peripheral vestibular loss using techniques taught to him by his physical therapist. The
patient reported no falls or near falls since his initial evaluation. At this office visit, the
patient inquired as to the availability of vestibular prosthetic devices2,3 and was advised
that at this time no such devices were commercially available.

Summary

A 71-year-old man presented with a complaint of oscillopsia, gait instability that was worse
in dimly lit environments and when walking on uneven surfaces, and discomfort in
complex visual environments including grocery stores. The patient had fallen without
injury on several occasions. History suggested bilateral peripheral vestibular loss of 20
years’ duration secondary to gentamicin ototoxicity with a recent decline in function
following placement of a coronary artery stent and starting zolpidem 5 mg at bedtime
and alprazolam on an as-needed basis. Physical examination and laboratory testing indi-
cated a reduction in both vestibulo-ocular and vestibulospinal function and a surface
dependent pattern on posturography. The patient was given a diagnosis of a decompensated
bilateral peripheral vestibular loss. Treatment consisted of discontinuation of zolpidem and
alprazolam and balance rehabilitation therapy, which led to decreased falls and improved
balance.

Teaching Points

1. Patients with long-standing bilateral peripheral vestibular loss can decompensate

and present as if they had a recent bilateral peripheral vestibular insult.
2. Patients with bilateral peripheral vestibular loss are prone to falls especially if they
are older individuals.
298 VESTIBULAR DISORDERS

3. Treatment of patients with decompensated bilateral peripheral vestibular loss

consists of physical therapy, discontinuation of vestibular suppressive
medications, and optimizing non-vestibular sensory inputs such as vision and
somatosensation.

References

1. Waterston JA, Barnes GR, Grealy MA, Luxon LM: Coordination of eye and head movements
during smooth pursuit in patients with vestibular failure. J Neurol Neurosurg Psychiatry
55(12):1125–1131, 1992.
2. Davilov YP, Tyler ME, Skinner KL, Bach-y-Rita P: Efficacy of electrotactile vestibular
substitution in patients with bilateral vestibular and central balance loss. Conf Proc IEEE Eng
Med Biol Soc Suppl 6605:9, 2006.
3. Goebel JA, Sinks BC, Parker BE Jr, Richardson NT, Olowin AB, Cholewiak RW: Otol
Neurotol 30(2):210–216, 2009.
Case 45
Autoimmune Inner Ear
Disease

History

A 33-year-old woman who worked in a day-care center presented with a chief complaint of
hearing loss and disequilibrium that had gradually worsened over 14 months. The patient
noted that her symptoms were more or less constant, with periodic exacerbations. Her
dizziness was characterized by lightheadedness and a sense of disequilibrium exacerbated
by rapid head movements and ambulation. She also noted that her hearing in both ears was
impaired and periodically worsened, improving subsequently, but sometimes not to her
baseline. The patient had no significant medical history. There was no reported abnormal
strength or sensation. Aside from some blurred vision during episodes of extreme dizzi-
ness, there were no visual symptoms. The family history was negative. Meclizine had been
prescribed, with no benefit.
Question 1: Based on the patient’s history, what are the diagnostic considerations?
Answer 1: This patient has a history consistent with a peripheral vestibulopathy.
Based on the presence of bilateral hearing loss, the patient may be suffering from
bilateral otologic disease. Given the information available from the history, the
differential diagnosis for the patient’s condition is broad. However, the progressive
nature of the illness and the associated symptoms of bilateral hearing loss render
some diagnoses more likely than others. Meniere’s disease (see Cases 9, 12, 20, 24
29, 42), ototoxicity (see Case 4), neurosyphilis, HIV infection, Lyme disease, auto-
immune inner ear disease, Cogan’s syndrome,1 bilateral acoustic neuroma asso-
ciated with neurofibromatosis Type 2, and otosclerosis (see Case 51) are all
possible.

Physical Examination

Neurologic examination revealed a left-beating nystagmus on left gaze. There were no

other abnormalities of cranial nerves. Motor examination, sensation, and coordination
were normal. The patient had a very wide-based and unsteady gait. Romberg’s test was
negative. Otoscopy was normal. Audibility of finger rub was absent bilaterally. She
demonstrated some difficulty understanding speech during the interview, especially

299
300 VESTIBULAR DISORDERS

when lip-reading was prevented. Weber’s test was midline, and the Rinne test was positive
bilaterally. Neurotologic examination revealed left-beating nystagmus with infrared gog-
gles in the primary position that was worsened by left lateral gaze. There was a left-beating
post-head-shake nystagmus. The head thrust test was abnormal bilaterally. The patient was
unable to stand on a compliant surface even with her eyes open.
Question 2: Does the physical examination help to establish a diagnosis? What laboratory
tests should be ordered to rule out other diagnostic possibilities?
Answer 2: The presence of abnormal head thrust tests bilaterally and abnormal
postural control on physical examination suggests bilateral vestibular hypofunc-
tion. Together with bilateral hearing impairment these findings support the idea of
bilateral otologic disease. The presence of spontaneous nystagmus suggests a
vestibular system imbalance or a recent change in vestibular function. Laboratory
testing should be performed to document the extent and type of hearing loss and
the extent of vestibular involvement. An MRI scan should be performed, with
special attention to the internal auditory canals. Blood studies should include
rheumatologic studies, a serum FTA-ABS, HIV, Lyme titers.

Laboratory Testing

Videonystagmography: Ocular motor function was normal, with the exception of a left-
beating spontaneous vestibular nystagmus. There was a direction-fixed left-beating posi-
tional nystagmus of 6 degrees per second. Alternate binaural bithermal caloric responses
were absent bilaterally. A minimal response to ice-water irrigation was apparent on the
right, and responses were absent on the left.
Rotational testing revealed markedly reduced responses and a left-directional prepon-
derance.
Posturography indicated excessive sway on conditions 4, 5, and 6, that is, a surface
dependence pattern.
Audiometric testing revealed a bilateral flat sensorineural hearing loss of moderate to
severe degree. The word recognition score was 60% in the right ear and 80% in the left ear
(Case 45: Figure 1).
VEMPs were absent bilaterally.
An MRI scan of the brain was normal.
Other: Serum FTA-ABS, HIV, and Borrelia burgdorferi (Lyme) titers were all negative.
The erythrocyte sedimentation rate was slightly elevated; serum immunoglobulin levels,
antinuclear antibody, rheumatoid factor, circulating immune complexes, and C3 and C4
levels were all normal.

Diagnosis/Differential Diagnosis

Question 3: Based on the history, physical examination, and laboratory test results, what is
the most likely diagnosis?
Answer 3: Because there is no evidence for ototoxic drug exposure, syphilis, or
neurofibromatosis, this patient’s bilateral, rapidly progressive hearing loss
with vestibular dysfunction suggests a diagnosis of autoimmune inner ear
disease.
 CASE 45: AUTOIMMUNE INNER EAR DISEASE 301

Case 45: Figure 1 Audiogram.

Question 4: What is autoimmune inner ear disease?

Answer 4: Autoimmune inner ear disease (AIED) is a disorder characterized by
rapidly progressive hearing loss that most often is bilateral and is thought to be
produced by damage mediated by both cellular and humoral immune mechan-
isms.2,3 AIED refers to a pathology restricted to the ear (i.e., primary autoimmune
inner ear disease.
Question 5: What are the manifestations of autoimmune inner ear disease?
Answer 5: Autoimmune inner ear disease is usually bilateral, but it can begin
unilaterally and rapidly progress to involve both sides. In its early stages, autoim-
mune disease may present in a fashion similar to endolymphatic hydrops with
fluctuations of hearing, but the overall course is progressive hearing impairment.
Approximately 50% of patients have symptoms of vestibular dysfunction, with 20%
of patients experiencing episodes of vertigo consistent with those seen in Meniere’s
disease.4 Bilateral vestibular hypofunction may also occur.5
Question 6: Are there any diagnostic tests that can confirm the diagnosis of autoimmune
inner ear disease?
Answer 6: There are currently no well-accepted diagnostic tests that can confirm the
diagnosis of autoimmune inner ear disease, although a positive immunologic
battery or elevated sedimentation rate may be suggestive. The diagnosis is usually
one of exclusion and rests on clinical criteria and response to treatment (see later
text). Several experimental tests are being studied that include testing patients’
serum against inner ear antigens using Western blot analysis, the lymphocyte
transformation test, and the migration inhibition test. These tests show some
302 VESTIBULAR DISORDERS

promise of detecting an autoimmune inner ear disorder. Recently, a commercially

available Western blot for detection of an antibody that binds to a 68-kDa antigen
derived from bovine temporal bone extract has become the most commonly used
blood test for AIED.6 A positive test result is thought to predict a positive response to
steroid treatment. Further studies are necessary to determine whether this test has
sufficient sensitivity and specificity to rule in or rule out the diagnosis of AIED.
Development of more antigen-specific tests is likely to increase the sensitivity and
specificity of blood testing for autoimmune inner ear disease.4,6,7,8,9 For example,
Yoo10 has reported the detection of autoantibodies to type II collagen in autoim-
mune inner ear disease, and animal studies have furthered the current concepts
involving autoimmune inner ear disease.11–13 Thus, patients with suspected auto-
immune disease of the ear should undergo blood tests similar to those used for the
evaluation of systemic autoimmune disease. Moreover, because autoimmune inner
ear disease is a feature of Cogan’s syndrome, which is characterized by autoimmune
inner ear disease and nonsyphilitic interstitial keratitis, slit lamp evaluation to search
for interstitial keratitis should be undertaken.
Question 7:What are the cochleovestibular manifestations of systemic autoimmune disease?
Answer 7: Several autoimmune diseases have been associated with cochleovestib-
ular dysfunction. The nature of this dysfunction is not well characterized but may
include both unilateral and bilateral disease. Hearing loss is better documented
than vestibular involvement. As such, in patients with suspected AIED, an appro-
priate review of systems should include questions pertaining to recurrent or chronic
ocular disease, nephritis, arthritis, pneumonitis, sinusitis, and inflammatory bowel
disease.14 Case 45: Table 1 lists those autoimmune disorders in which cochleoves-
tibular findings have been reported.
Question 8:What treatments have been advocated for autoimmune inner ear disease?
Answer 8: The most widely accepted treatment of autoimmune inner ear disease
includes corticosteroids such as prednisolone 1 mg/kg per day for 4 weeks followed
by a tapering dose. Often, patients require long-term treatment to prevent relapse.
Cytotoxic agents such as azathioprine, methotrexate, and cyclophosphamide have
also been advocated as an adjunct to steroid therapy.15 A recent clinical trial using
methotexate to spare long-term steroid use in AIED failed to show efficacy.16
Etanercept, an inhibitor of tumor necrosis factor-alpha, has also been proposed;17
but a recent clinical trail failed to show efficacy.18 Last, intratympanic steroid therapy
and plasmapheresis have been proposed but limited data are currently available.19,20

Case 45: Table 1 Systemic Autoimmune Diseases Associated with

Inner Ear Manifestations

Systemic lupus erythematosus

Rheumatoid arthritis
Vasculitides
Polyarteritis nodosa
Wegener’s granulomatosis
Cogan’s syndrome
Behcet’s disease
Ulcerative colitis
Source: Adapted with permission from Barna GB, Hughes BP: Autoimmunity and
otologic disease: Clinical and experimental aspects. Clin Lab Med 8:389, 1988.21
 CASE 45: AUTOIMMUNE INNER EAR DISEASE 303

Treatment/Management

The patient was treated with steroids in the form of oral prednisolone, 60 mg daily for 4
weeks. During this time, she experienced improvement in hearing, especially in her ability
to understand speech, and a slight improvement in balance. After the 4-week course of
high-dose steroids, the dose was slowly tapered over 30 days. When dosage reached 5 mg
daily, the patient noticed worsening of her hearing and balance. The steroid dose was then
increased to 20 mg every other day, after which her hearing stabilized. The patient was
enrolled in a vestibular rehabilitation program and noticed gradual improvement of
balance.
Based on the clinical history and response to steroid therapy, the patient was given the
diagnosis of autoimmune inner ear disease.

Summary

A 33-year-old woman presented with bilateral hearing loss and disequilibrium that had
gradually worsened over 14 months. On examination, the patient was found to have
bilateral hearing loss, evidence for bilateral vestibular hypofunction, and spontaneous
vestibular nystagmus. Laboratory testing revealed bilateral sensorineural hearing loss,
bilateral vestibular loss with a vestibular asymmetry, and a normal MRI scan. Blood
studies did not show evidence of an infectious process. Immunologic parameters were
normal, with the exception of a mildly elevated erythrocyte sedimentation rate. On the
basis of the patient’s clinical presentation and positive response to a trial of steroids, the
diagnosis of autoimmune inner ear disease was made. Treatment consisted of high-dose
corticosteroids and vestibular rehabilitation. The patient’s hearing loss and vestibular
symptoms stabilized.

Teaching Points

1. Bilateral otologic disease can cause dizziness symptoms consistent with peripheral
vestibular dysfunction in conjunction with bilateral hearing loss. The differential
diagnosis for this clinical situation includes bilateral Meniere’s disease, ototoxicity,
neurosyphilis, HIV infection, Lyme disease, autoimmune inner ear disease, bilateral
acoustic neuroma associated with neurofibromatosis, and otosclerosis.
2. Autoimmune inner ear disease is a disorder characterized by auditory and
vestibular dysfunction that most often is bilateral and is thought to be produced
by damage mediated by both cellular and humoral immune mechanisms.
Autoimmune inner ear disease is usually bilateral but may begin unilaterally and
progress rapidly to involve both sides.
3. A diagnosis of autoimmune inner ear disease is difficult to confirm. A positive
immunologic battery or an elevated erythrocyte sedimentation rate may be
suggestive. Thus, patients with suspected autoimmune inner ear disease should
undergo blood tests similar to those used for the evaluation of systemic autoimmune
disease. Also, slit lamp evaluation to search for interstitial keratitis, a component of
Cogan’s syndrome, should be undertaken. Autoimmune inner ear disease is often a
diagnosis of exclusion and frequently depends on clinical criteria and the response to a
trial of corticosteroid therapy.
304 VESTIBULAR DISORDERS

4. Systemic autoimmune diseases can be associated with cochleovestibular

dysfunction. Case 45: Table 1 lists the systemic autoimmune diseases in which
cochleovestibular findings have been reported.
5. Treatment of autoimmune inner ear disease usually includes corticosteroids, such as
prednisolone, 1 mg/kg per day for 4 weeks, followed by a tapering dose and a
maintenance dose if a positive response has occurred. Cytotoxic agents such as
azathioprine and cyclophosphamide have also been advocated as an adjunct if the
disease stops responding to steroid therapy. Plasmapheresis may be effective.

References
1. Cogan DS: Syndrome of nonsyphilitic interstitial keratitis and vestibuloauditory symptoms.
Arch Ophthalmol 33:144, 1945.
2. Veldman JE, Roord JJ, O’Connor AF, Shea JJ: Autoimmunity and inner ear disorders: An
immune-complex mediated sensorineural hearing loss. Laryngoscope 94:501, 1984.
3. Griffith AJ: Biological and clinical aspects of autoimmune inner ear disease. Yale J Biol Med
65:17–28, 1992.
4. Moscicki RA, San Martin JE, Quintero CH, Rauch SD, Nadol JB Jr, Bloch KJ: Serum antibody
to inner ear proteins in patients with progressive hearing loss. JAMA 272:611–616, 1994.
5. Deutschlander A, Glaser M, Strupp M, Dieterich M, Brandt T: Immunosuppressive treatment
in bilateral vestibulopathy with inner ear antibioties. Acta Otolaryngol 125(8):848–851, 2005.
6. Harris JP, Sharp PA: Inner ear autoantibodies in patients with rapidly progressive sensor-
ineural hearing loss. Laryngoscope 100:516–524, 1990.
7. Yamanobe S, Harris JP: Inner ear-specific antibodies. Laryngoscope 103:319–326, 1993.
8. Hughes GB, Barna BP, Kinney SE, Calabrese LH, Nalepa NL: Predictive value of laboratory
tests in ‘‘autoimmune’’ inner ear disease: Preliminary report. Laryngoscope 96:502–505, 1986.
9. Agrop C, Luxon LM. Immune-related inner ear disorders in neuro-otology. Curr Opin Neurol
19(1):26–32, 2006.
10. Yoo TJ: Etiopathogenesis of Meniere’s disease: A hypothesis. Ann Otol Rhinol Laryngol
93(Suppl 113):6–12, 1984.
11. Soliman AM: Experimental autoimmune inner ear disease. Laryngoscope 99:188–194, 1989.
12. Yoo TJ, Yazawa Y, Tomoda K, Floyd R: Type II collagen-induced autoimmune endolym-
phatic hydrops in guinea pig. Science 222:65–67, 1983.
13. Harris JP: Immunologic mechanisms in disorders of the inner ear. Otolaryngol Head Neck
Surg Update 1:380–395, 1989.
14. Ruckenstein MJ. Autoimmune inner ear disease. Curr Opinion Otolaryngol Head Neck
Surgery 12(5):426–430, 2004.
15. McCabe BF: Autoimmune inner ear disease: Therapy. Am J Otolaryngol 10:196–197, 1989.
16. Harris JP, Weisman MH, Derebery JM, et al: Treatment of corticosteroid-responsive auto-
immune inner ear disease with methotrexate: A randomized controlled trial. JAMA
290:1875–1883, 2003.
17. Rahman MU, Poe DS, Choi HK: Etanercept therapy for immune-mediated cochleovestibular
disorders: Preliminary results in a pilot study. Otol Neurotol 22(5):619–624, 2001.
18. Cohen S, Shoup A, Weisman M, Harris J: Etanercept treatment for autoimmune inner ear
disease: Results of a pilot placebo-controlled study. Otol Neurotol. 26(5):903–907, 2005.
19. Luetje CM: Theoretical and practical implications for plasmapheresis in autoimmune inner
ear disease. Laryngoscope 99:1137–1146, 1989.
20. Garcia-Berrocal JR, Ibanez A, Rodriguez A, Gonzalez-Garcia JA, Verdaguer JM, Trinidad A,
Ramirez-Camacho R: Alternatives to systemic steroid therapy for refractory immune-
mediated inner ear disease: A physiopathologic approach. Eug Arch Otorhinolaryngol
263(11):977–982, 2006.
21. Barna GB, Hughes BP: Autoimmunity and otologic disease: Clinical and experimental
aspects. Clin Lab Med 8:389, 1988.
Case 46
Progressive Supranuclear
Palsy

History

A 58-year-old woman who did not work outside the home complained of frequent falling.
The patient’s symptoms had begun several years previously, were gradually worsening, and
did not fluctuate on a day-to-day basis. There was particular difficulty going down steps and
stepping from the sidewalk to the street. The patient’s spouse stated that she had some
slowing of mentation and slurred speech. The patient had no complaint of vertigo or of
hearing loss or tinnitus. There was no medical history of significance and no family history of
neurologic or otologic disease. The patient’s primary care physician had performed a CT
scan, which was normal, and had given the patient a diagnosis of Parkinson’s disease. The
patient had not responded to dopaminergic or anticholinergic agents.
Question 1: Based on the patient’s history, what is the differential diagnosis?
Answer 1: This patient’s history is most consistent with a progressive neurodegen-
erative syndrome, such as progressive supranuclear palsy, Parkinson’s disease,
striatonigral degeneration, or dementia with associated cerebellar signs. The differ-
ential diagnosis also includes multiple cerebral infarctions, hypothyroidism, central
nervous system vasculitis, and a central nervous system neoplastic condition such as
central nervous system lymphoma.

Physical Examination

The general examination revealed a disheveled woman who appeared to be depressed.

Neurologic examination revealed limitation of vertical gaze, especially downward gaze
during voluntary eye movements. There was severe slowing of vertical saccades and
minimal slowing of horizontal saccades. Square-wave jerks were noted. There was sacca-
dic pursuit and abnormal convergence. Doll’s eyes (oculocephalic reflexes) revealed a full
range of extraocular motion vertically and horizontally. Bell’s phenomenon, that is, upgaze
during blinks, was absent. The patient had a masked facies with a decreased blink rate.
There was a hyperactive gag reflex. Motor system examination revealed increased tone
with increased deep tendon reflexes that were symmetric. The plantar response was
equivocal bilaterally. Sensation was normal. Coordination revealed slowing of alternating

305
306 VESTIBULAR DISORDERS

Case 46: Figure 1 Sagittal MRI of a patient with progressive supranuclear palsy. Note the
flattened quadrigeminal plate.
Source: With permission from Slowinski J et al: MR imaging of brainstem atrophy in progressive
supranuclear palsy. J Neurol 255:37-44, 2008. 8

movements and slowing on finger-to-nose testing without dysrhythmia. Romberg’s test

was negative. Evaluation of the patient’s gait revealed a widened base, short stride length,
and retropulsion. The otologic examination was normal.
Question 2: Based upon the additional information from the physical examination, what is
this patient’s likely diagnosis? What laboratory testing is appropriate?
Answer 2: This patient’s physical examination is consistent with progressive supra-
nuclear palsy. Because of the poor prognosis for progressive supranuclear palsy and
its poor response to treatment, an MRI scan should be performed before giving this
diagnosis. Also, hematologic and thyroid blood studies should be performed and
the erythrocyte sedimentation rate should be obtained.

Laboratory Testing

An MRI scan of the brain suggested midbrain atrophy (Case 46: Figure 1).
A complete blood count was normal.

Diagnosis/Differential Diagnosis

This patient was given a diagnosis of progressive supranuclear palsy.

Question 3: What are the manifestations of progressive supranuclear palsy?
Answer 3: The manifestations of progressive supranuclear palsy are given in Case 46:
Table 1.
Question 4: What is the pathophysiology of progressive supranuclear palsy?
Answer 4: Progressive supranuclear palsy is characterized by cell loss in many
locations including the midbrain (substantia nigra, red nucleus, superior colliculus),
 CASE 46: PROGRESSIVE SUPRANUCLEAR PALSY 307

Case 46: Table 1 Manifestations of Progressive Supranuclear Palsy

Decreased cognitive ability

Abnormal ocular motor function
Square-wave jerks
Limitation of vertical eye movement
Slow or absent vertical saccades
Hypometric horizontal saccades
Saccadic pursuit
Abnormal convergence
Normal oculocephalic reflexes
Bell’s phenomenon typically absent
Masked facies
Dysarthria
Dysphagia
Rigidity
Abnormal gait
Midbrain atrophy on CT

the corpus striatum (especially the globus pallidus), and the dentate nucleus of the
cerebellum.1,2
As discussed in Chapter 1, the midbrain is important for vertical and torsional eye
movements in much the same way that the pons is important for horizontal eye
movements. A premotor center in the midbrain important for vertical saccades is the
rostral interstitial nucleus of the medial longitudinal fasciculus.3 It is comparable to the
paramedian pontine reticular formation, which is important for horizontal saccades.
Other structures that are important for the vertical and torsional VOR include the
posterior commissure; the interstitial nucleus of Cajal; the third and fourth cranial
nerve nuclei; and the medial longitudinal fasciculus, which carries signals from the
medulla and the pons to the midbrain.3,4 The midbrain is also important for vergence
eye movements. Thus, midbrain lesions can cause limitation of vertical eye move-
ments, vertical nystagmus, skew deviation (a vertical ocular misalignment), abnormal
vergence, and an abnormal vertical and/or torsional VOR.A recent study suggests that
otolith-mediated reflexes may be especially altered in progressive supranuclear palsy.5
Question 6: What disease states are associated with midbrain dysfunction?
Answer 6: Disorders that affect the midbrain include degenerative disorders, such as
progressive supranuclear palsy; mass lesions, such as pinealoma; infarction, such as the
‘‘top of the basilar syndrome’’;6 midbrain hemorrhage; hydrocephalus; and encephalitis.

Treatment/Management

The patient was treated with a course of bromocryptine. The patient also underwent
balance and eye movement training.7 This provided minimal symptomatic relief for several
months, after which time the patient began a progressive and relentless decline.

Summary

A 58-year-old woman presented with a chief complaint of frequent falling, slowed cogni-
tion, blurred vision, and personality change. Examination revealed marked limitation of
308 VESTIBULAR DISORDERS

downgaze, square-wave jerks, and retropulsion of gait. The MRI scan suggested midbrain
atrophy. The patient was given the diagnosis of progressive supranuclear palsy. She had
been unresponsive to dopaminergic and anticholinergic agents. A course of bromocryptine
provided minimal benefit.

Teaching Points

1. The gradual onset and worsening of imbalance in the absence of vertigo suggests a
progressive neurologic disorder.
2. Progressive supranuclear palsy is a disorder characterized by the gradual onset of
cognitive decline and poor balance. Progressive supranuclear palsy is caused by cell
loss in many locations, including the midbrain (substantia nigra, red nucleus, superior
colliculus), the basal ganglia (especially the globus pallidus), and the dentate nucleus of
the cerebellum.
3. The midbrain is important for vertical, torsional, and vergence eye movements.
Thus, midbrain lesions can cause limitation of vertical eye movements, vertical
nystagmus, skew deviation, an abnormal vertical and/or torsional VOR, and abnormal
vergence.
4. The midbrain is also important for vergence eye movements.
5. Disorders that affect the midbrain include degenerative disorders, such as
progressive supranuclear palsy; mass lesions, such as pinealoma; infarction, such
as the top of the basilar syndrome; midbrain hemorrhage; hydrocephalus; and
encephalitis.

References
1. Steele JC, Richardson JC, Olszewski J: Progressive supranuclear palsy. Arch Neurol
10:333–359, 1964.
2. Behrman S, Carroll JD, Janota I, Matthews WB: Progressive supranuclear palsy. Brain
92:663–678, 1969.
3. Buttner-Ennever JA (ed): Neuroanatomy of the Oculomotor System. Amsterdam: Elsevier,
1988.
4. Leigh RJ, Zee DS: The Neurology of Eye Movements, ed 4. New York: Oxford University
Press, 2006.
5. Liao K, Wagner J, Joshi A, Estrovich I, Walker MF, Strupp M, Leigh RJ: Why do patients with
PSP fall? Evidence for abnormal otolith responses. Neurology 70(10):802–809, 2008.
6. Caplan L: Top of the basilar syndrome. Neurology 30:72–79, 1980.
7. Zampiere C, DiFabio RP: Improvement of gaze control after balance and eye movement
training in patients with progressive supranuclear palsy: A quasi-randomized controlled trial.
Arch Physical Medicine & Rehabil 90(2):263–270, 2009.
8. Scully RE, Mark E, McNeely W, McNeely B: Weekly clinicopathological exercises. N Engl J
Med 329:1560, 1993.
Case 47
Lithium-Induced Dizziness

History

A 40-year-old female administrative assistant presented with the gradual onset of constant
dizziness and disequilibrium for the last several months. The patient noted minimal day-to-
day fluctuation of symptoms. She complained of unsteadiness, jumping of her vision,
difficulty breathing, and difficulty driving. She denied having spontaneous episodes of
vertigo and reported no positionally provoked vertigo. The patient’s medical history was
significant for a bipolar affective disorder that had been treated with lithium for 20 years.
There was no prior history of dizziness or disequilibrium. The family history was sig-
nificant for depression.
Question 1: Based on the patient’s history, what diagnoses should be considered?
Answer 1: The absence of vertigo suggests that a peripheral vestibular disorder is
unlikely. A possible central nervous system disorder is suggested by the nonfluctu-
ating visual difficulties and constant unsteadiness. Considerations include anxiety-
related dizziness, migraine-related dizziness, medication side effect, chronic fatigue
syndrome, a posterior fossa mass lesion, and cerebellar degeneration. Based upon
the patient’s history of bipolar affective disorder and long-term use of lithium, a
medication side effect should be strongly considered.1–4

Physical Examination

General examination was normal. Neurologic examination revealed downbeating nystag-

mus in center gaze and impaired tandem walking. The remainder of the neurologic
examination was normal. Neurotologic examination revealed no spontaneous nystagmus,
a normal head thrust test, a negative Dix-Hallpike test except for a continuous downbeating
nystagmus, and difficulty maintaining stability on a foam pad with the eyes closed.
Question 2: What is the significance of this patient’s abnormal physical examination?
Answer 2: The downbeating nystagmus observed during fixation with the patient
seated and during positioning testing suggests a central nervous system disorder.
The pathophysiology of downbeating nystagmus (see Case 34) includes an imbal-
ance of up versus down ocular motor drive, which can occur as a result of a central

309
310 VESTIBULAR DISORDERS

vestibular imbalance or an imbalance related to down versus up ocular pursuit.5 The

localization for downbeating nystagmus includes the caudal midline cerebellum.
Question 3: Would laboratory testing be helpful in establishing a diagnosis?
Answer 3: An MRI scan is essential to rule out a structural abnormality. Vestibular
laboratory testing would provide additional information regarding possible coex-
isting labyrinthine dysfunction and the vestibulo-ocular reflex. This information
may be helpful in determining the basis for the patient’s symptoms.

Laboratory Testing

Videonystagography: Ocular motor testing revealed downbeating nystagmus without other

abnormalities. Caloric and rotation responses were normal.
Audiometry was normal.
MRI scan of the brain was normal. The blood magnesium level was normal.
Question 4: What is the significance of this patient’s vestibular laboratory test results?
Answer 4: Laboratory testing indicated that there was no peripheral vestibular
dysfunction and no abnormality of the horizontal VOR. Brain imaging and blood
testing did not disclose a cause for the patient’s downbeating nystagmus.

Diagnoses/Differential Diagnosis

Question 5: Based upon the information available, what is the most likely diagnosis?
Answer 5: The patient’s history, physical examination, and laboratory test results
suggest a central nervous system disorder related to vertical ocular motor tone.1
Additionally, based upon the patient’s complaint of imbalance, it is likely that she is
suffering from a central vestibular disorder affecting the vestibular spinal system,
although her vertical nystagmus may be impairing her vision and thereby interfer-
ing with her upright balance. The most likely cause of this patient’s complaints is a
side effect of lithium, which is noted to cause downbeating nystagmus.2–6
This patient was given the diagnosis of lithium-induced dizziness, disequilibrium,
and downbeating nystagmus.

Treatment/Management

After consulting with the patient’s psychiatrist, lithium was discontinued and valproic acid
was started. At a follow-up evaluation 3 months later, the patient’s downbeating nystagmus
had diminished to some extent, as had her dizziness and disequilibrium, although she was
still symptomatic. The patient was given a trial of gabapentin, without benefit.

Summary

A 40-year-old woman with a history of bipolar affective disorder treated with lithium
presented with constant symptoms of dizziness and disequilibrium. The patient was found
to have downbeating nystagmus and no evidence of peripheral vestibular dysfunction on
vestibular laboratory. She was given a diagnosis of lithium-induced dizziness.
 CASE 47: LITHIUM-INDUCED DIZZINESS 311

Discontinuation of lithium provided incomplete relief, and the downbeating nystagmus

persisted. A trial of gabapentin was unsuccessful.

Teaching Points

1. Long-term use of lithium can cause downbeating nystagmus. The onset of this
disorder is often insidious even if therapeutic levels of the medication are maintained.
Discontinuation of lithium may or may not be associated with a reduction of symptoms
and signs.
2. The discontinuation of certain medications can be associated with dizziness and
disequilibrium. Examples include medications that are successfully controlling
dizziness, selective serotonin reuptake inhibitors, and scopolamine.

References
1. Gracia F, Koch J, Aziz N: Downbeat nystagmus as a side effect of lithium carbonate: Case
report. J Clin Psychiatry 46:292–293, 1985.
2. Williams DP, Troost BT, Rogers J: Lithium-induced downbeat nystagmus. Arch Neurol
45:1022–1023, 1988.
3. Halmagyi GM, Lessell I, Curthoys IS, Lessell S, Hoyt WF: Lithium-induced downbeat
nystagmus. Am J Ophthalmol 107:664–670, 1989.
4. Corbett JJ, Jacobson DM, Thompson HS, Hart MN, Albert DW: Downbeating nystagmus and
other ocular motor defects caused by lithium toxicity. Neurology 39:481–487, 1989.
5. Leigh RJ, Zee DS: The Neurology of Eye Movements, ed 4. New York: Oxford University
Press, 2006.
6. Wagner JN, Glaser M, Brandt T, Strupp M: Downbeat nystagmus: Aetiology and comorbidity
in 117 patients. J Neurol Neurosurg Psychiatry. doi:10.1136/jnnp.126284, 2007.
Case 48
Congenital Inner Ear
Malformations

History

A 16-year-old girl reported an acute onset of hearing loss, tinnitus, and disequilibrium.
These symptoms began following a high school football game 7 days earlier. The patient, a
majorette in the high school band, was seated in the grandstands in front of the bass drum.
The football game was very exciting and the drummer had enthusiastically beaten his drum
during the game. The patient had felt pain in her ears several times and then a full feeling in
her right ear. Following the game, she noted bilateral loss of hearing, nonlocalized tinnitus,
and unsteadiness. She claimed that she could not hear at all and that the world around her
seemed to bounce or jiggle when she moved her head quickly.
There was a past history of a left-sided hearing loss of unknown etiology that was first
noticed at age 5.
The following day, the patient was seen by an otolaryngologist who examined her ears
and performed an audiogram that confirmed a profound loss of hearing in both ears. The
otolaryngologist prescribed oral prednisone and referred the patient for further evaluation.
Question 1: What are the possible causes of this patient’s new loss of hearing and of her
vestibular symptoms?
Answer 1: The patient may have suffered from acoustic trauma or a temporary
threshold shift (see later text) from the pounding of a bass drum close to her ears
during an exciting football game. Acoustic trauma generally refers to a single high-
intensity acoustic event such as a firecracker or gun discharging near an unprotected
ear. Acoustic trauma can damage hair cells within the cochlea, thereby causing an
immediate and permanent sensorineural hearing loss that involves the midfre-
quency hearing range between 3 and 6 kHz and is typically centered at 4 kHz.
Mild, temporary vestibular symptoms are not unusual in cases of acoustic trauma.
In this patient’s case, it is possible that a single note, aggressively played from the
bass drum close to the patient’s unprotected ear, caused acoustic trauma.
A temporary threshold shift is a temporary increase in auditory thresholds of 10
to 20 dB usually involving the mid to high frequencies (3 to 6 kHz). A temporary
threshold shift often occurs after sustained exposure to high-intensity noise.
Associated symptoms include high-pitched tinnitus and a sense of fullness in the
ear. Vestibular symptoms are not generally noted during temporary threshold

312
 CASE 48: CONGENITAL INNER EAR MALFORMATIONS 313

shifts. The symptoms of a temporary threshold shift are usually fully reversible over
12 to 24 hours and are thought to be the result of an acute over-consumption of
essential metabolic factors within the inner ear. A permanent shift in hearing
thresholds primarily affecting the high-frequency range can occur following
repeated temporary threshold shifts and is referred to as noise-induced hearing
loss. The incidence of both temporary threshold shifts and noise-induced hearing
loss have increased recently in teenagers, primarily because of noise exposure at
rock concerts and from the use of personal musical devices at high loudness levels.
Because this patient’s hearing loss did not resolve and she has vestibular symptoms,
she is probably suffering from the results of acoustic trauma caused by the proximity
to a loud bass drum rather than from a temporary threshold shift.
Question 2: What are the possible causes of this patien’s preexisting unilateral hearing loss?
Answer 2: The differential diagnosis for hearing loss discovered during childhood is
summarized in Case 48: Table 1.
Hearing loss discovered at birth is caused by genetic factors in about 60% of
infants and nongenetic factors in 40%.In children with genetic hearing loss, 30%
will display syndromic features while 70% will be non-syndromic.Non-syndromic
hearing loss is most commonly recessive (70%), less commonly autosomal domi-
nant (15%–25%), and more rarely x-linked or mitochondrial.1 The most common
non-syndromic form of congenital hearing loss is due to mutation in the connexin
26 gene, which can account for 25% of all cases of congenital deafness.2 Most
commonly, congenital hearing loss is bilateral and sensorineural but unilateral
congenital sensorineural hearing loss is found in 5%–10% of children following
newborn hearing screening. The nongenetic perinatal causes of hearing loss are
also listed in Case 48: Table 1. Congenital cytomegalovirus infection is most com-
mon, likely accounting for 15%–20% of all children born with hearing loss.3 These

Case 48: Table 1 Summary of the Differential Diagnosis of

Sensorineural Hearing Loss in Children

Inherited
Congenital
Noncongenital
Acquired
Prenatal
Infectious
Inner ear malformations
Perinatal
Infectious
Hyperbilirubinemia
Prematurity, birth trauma, anoxia
Persistent fetal circulation
Postnatal
Infectious
Head trauma
Acoustic trauma
Noise-induced
Perilymphatic fistula
Endolymphatic hydrops
314 VESTIBULAR DISORDERS

etiologies can often be ruled out by reviewing the child’s history of perinatal
hospitalization or complications at birth.
The postnatal causes of childhood hearing loss include infection, such as
bacterial or viral meningitis. Mumps labyrinthitis commonly causes unilateral
hearing loss although measles/mumps/rubella vaccination has reduced the inci-
dence of virally induced hearing loss in children. Head trauma, acoustic trauma,
and noise-induced hearing loss are common causes of hearing loss, especially
affecting teenagers, and should be sought out in the patient interview.4
Perilymphatic fistula can cause both hearing loss and vestibular disturbances.5
The presence of inner malformations or head trauma may contribute to the
formation of a perilymphatic fistula (see Case 60). Endolymphatic hydrops can
occur in childhood and produces a symptom complex of recurrent vertigo,
fluctuating hearing loss, tinnitus, and aural fullness similar to that seen in adults.6
Inherited hearing loss that develops beyond infancy may be associated with
other nonotologic abnormalities such as kidney disease (e.g., Alport’s syndrome),
ocular disease (e.g., Usher’s syndrome), pigmentary disorders (e.g., Waardenburg’s
syndrome), goiter and hypothyroidism (Pendred’s syndrome), bony abnormalities
(e.g., osteogenesis imperfecta), and mucopolysaccharide storage disease (e.g.,
Hurler’s syndrome and Hunter’s syndrome).
Question 3: Is vestibular dysfunction commonly present in children with hearing loss?
Answer 3: Preliminary data suggest that the incidence of vestibular abnormalities in
congenitally deaf individuals is 65%–85%, with severe vestibular hypofunction
noted in 25%–33%.7,8 While developmental delay in walking and mild gait instability
in childhood are common in these individuals, more severe or disabling symptoms
of vestibular dysfunction are rarely reported.The lack of vestibular symptoms
despite abnormal vestibular function may be a result of substitution of other
sensory modalities for the abnormal vestibular function and enhanced plasticity of
the pediatric brain. Also, patients with bilateral vestibular loss rarely have spontaneous
episodes of vertigo (see Cases 4 and 29).
Inherited noncongenital hearing loss may or may not be associated with vestibular
abnormalities. There are many patterns of hearing loss and vestibular dysfunction;
they vary in the relative affliction of hearing versus balance and in severity, age of
onset, and rate of progression. For example, Usher’s syndrome Type I, an inherited
autosomal recessive disorder characterized by severe to profound hearing loss and
retinitis pigmentosa, is associated with absent vestibular responses. Mixed X-linked
progressive deafness with stapes fixation, a condition in which males show pro-
gressive moderate to severe mixed hearing loss, is also associated with abnormal
vestibular function. Female carriers of this disorder have only mild hearing loss and
normal vestibular function.
Question 4: Are inner ear malformations likely to be associated with vestibular dysfunction?
Answer 4: Yes.A spectrum of inner ear malformations can occur ranging from total
agenesis to various combinations of bony and membranous abnormalities of the
cochlea and semicircular canals.9,10 Examples include Mondini dysplasia, the enlarged
vestibular aqueduct syndrome, and cochlear-saccular dysgenesis (i.e., Sheibe dyspla-
sia). Individuals with inner ear dysplasias may present with sudden or progressive
hearing loss in childhood or young adulthood. The hearing loss may be unilateral or
bilateral. Vestibular symptoms are frequently noted but generally are mild.A bump on
the head, a strong sneeze, or straining during a bowel movement may worsen the
 CASE 48: CONGENITAL INNER EAR MALFORMATIONS 315

hearing or vestibular symptoms associated with inner ear malformations.Many

patients with inner ear malformations have other abnormalities that comprise a
syndrome, such as Klippel-Feil syndrome, Pendred’s syndrome, trisomy syndrome,
branchio-oto-renal syndrome, CHARGE syndrome, and DiGeorge’s syndrome.Inner
ear dysplasias can also be associated with an abnormal communication between the
middle ear space and the cerebrospinal fluid space, that is, a perilymphatic fistula (see
Case 60). Children with this condition are at risk for recurrent meningitis.11

Additional History

Further history revealed no known familial hearing loss or history of consanguinity. The
patient was a full-term infant and there were no reported maternal complications of
pregnancy or delivery. The parents reported two episodes of high fever of unknown cause
during childhood. There was no history of head trauma or noise exposure.
Question 5: What is the most likely cause of this patien’s prior hearing loss? How does this
relate to the likely cause of this patien’s new hearing loss?
Answer 5: The negative maternal and perinatal history do not reveal the cause of the
prior left-sidedhearing loss first noticed at age 5. It is possible that the hearing loss may
have been related to a viral labyrinthitis during one of the episodes of high fever. The
prior hearing loss may also have been caused by an occult inner ear malformation.12
This idea is supported by the sudden loss of hearing in the contralateral ear precipitated
by acoustic trauma, which is suggestive of a bilateral inner ear malformation.

Physical Examination

Neurologic examination was normal.Otoscopic examination was normal.She could not

hear a whispered voice or finger rub in either ear. Neurotologic examination revealed no
spontaneous nystagmus with infrared goggles. Head thrust testing was abnormal both to the
right and to the left. No nystagmus or vertigo was noted during pressure changes in the
external auditory canal induced by a pneumatic otoscope. She could not stand on a
compliant foam pad with her eyes open or closed. Gait was mildly unsteady.
Question 6: How should the possibility of an inner ear malformation be evaluated with
laboratory testing?
Answer 6: Audiometric and vestibular testing can help to define the extent of audio-
vestibular abnormalities including severity and laterality. A high-resolution CT scan of
the temporal bones is most frequently used to diagnose an inner ear anatomic
malformation. Because most inner ear malformations include some degree of bony
labyrinthine abnormalities, they are easily detected and characterized by CT imaging,
which provides bony detail of the inner ear superior to that of MRI. However, recent
advances in MR imaging have led to visualization of the labyrinthine fluid spaces in
sufficient detail to characterize many inner ear malformations.13

Laboratory Testing

Videonystagmography: Ocular motor and positional testing were normal. Caloric testing
indicated absent response to bithermal stimulation and minimal responses to ice water
irrigation, that is, a severe bilateral vestibular reduction.
316 VESTIBULAR DISORDERS

Case 48: Figure 1 Audiogram.

Rotational testing revealed severely reduced gain and increased phase lead.
Posturography indicated excessive sway on conditions 4, 5, and 6, that is, a surface-
dependent pattern.
An audiogram (Case 48: Figure 1) showed a profound sensorineural hearing loss in the
left ear. The right ear showed a flat severe sensorineural hearing loss. Word recognition
was 0 in the left ear and 66% in the right ear.
CT imaging of the temporal bones showed the presence of a bilateral inner ear malforma-
tion consistent with the enlarged vestibular aqueduct syndrome (Case 48: Figure 2).

Diagnosis/Differential Diagnosis

This patient was given the diagnosis of enlarged vestibular aqueduct syndrome.
Question 7: What is the enlarged vestibular aqueduct syndrome?
Answer 7: The enlarged vestibular aqueduct syndrome is a congenital malformation
of the temporal bone in which the vestibular aqueducts are abnormally enlarged.14
This is the most common inner ear malformation found in children with hearing
loss.15 The vestibular aqueduct syndrome predisposes children to develop progres-
sive sensorineural hearing loss and vestibular dysfunction at a relatively early
age.10–16 An abnormally large vestibular aqueduct can occur as an isolated finding
or it can accompany more widespread congenital malformations of the cochlea and
semicircular canals.Enlarged vestibular aqueduct syndrome is a consistent feature
of Pendred’s Syndrome.The Pendred gene mutation has been identified (SLC26A4)
and screening for this mutation is now is commercially available.17
 CASE 48: CONGENITAL INNER EAR MALFORMATIONS 317

Case 48: Figure 2 Axial computed tomographic images showing bilateral dilated vestibular aqueducts.
(A) Soft-tissue algorithm shows the dilated endolymphatic sac (large arrow), seen here better on the left
side. The sac is a fluid-density structure adjacent to the contrast-enhanced sigmoid sinus (large
arrowhead). Enhancing dura defines the medial border of the sac (small arrowheads). (B) Bone algorithm
demonstrates the osseous anatomy of the inner ear. The osseous vestibular aqueduct is markedly enlarged
(white arrows). The labyrinthine vestibules (highlighted arrows) are slightly dysplastic.
With permission from Hirsch BE et al: Magnetic resonance imaging of the large vestibular aqueduct. Arch Otolaryngol
Head Neck Surg 118:1124-1127, 1992. 10

Question 8: What is the mechanism whereby acoustic trauma or barotrauma (a gradual but
large, rather than an abrupt but modest, change in external auditory canal pressure)
causes or exacerbates hearing loss and vestibular dysfunction in patients with inner ear
malformations?
Answer 8: Although the exact mechanism of hearing loss and vestibular dysfunction
as a result of acoustic trauma or barotrauma in patients with inner ear malformations
is unknown, two theories are most commonly proffered: (1) hearing and vestibular
dysfunction may result from an abnormal susceptibility to rupture of the mem-
branous labyrinth, or (2) hearing and vestibular dysfunction may result from a
perilymphatic fistula. In addition to avoiding acoustic trauma, that is, exposure to
excessively loud sounds and barotrauma, patients and their parents should be
counseled concerning avoidance of activities such as weightlifting, contact sports,
or scuba diving, which increase intrathoracic and cerebrospinal fluid pressure,
thereby increasing the likelihood of either rupture of inner ear membranes or the
development of a perilymphatic fistula.

Treatment/Management

The possibility of exploring the right ear for a perilymphatic fistula was discussed with the
patient and her family. It was decided that the patient complete a 2-week course of oral
prednisone at a dose of 1 mg/kg per day and remain at bed rest with minimal activity for 2
weeks in case the recent worsening of symptoms was a result of a pressure-induced
318 VESTIBULAR DISORDERS

membrane rupture. The patient’s symptoms stabilized. One month later, she resumed
normal activities and was counseled regarding avoidance of contact sports, straining, or
lifting heavy objects. She was fitted with a hearing aid in the right ear and asked to enroll in
a lip-reading class to help improve her communication skills. At 6-week follow-up, the
patient reported no further vertigo or disequilibrium and some subjective improvement in
hearing. Follow-up audiometric testing showed that word recognition scores had increased
to 85%, although pure tone thresholds were unchanged.

Summary

A 16-year-old girl presented with disequilibrium and a loss of hearing and tinnitus in an
only-hearing ear following acoustic trauma. A congenital bilateral inner ear malformation
was subsequently discovered by CT scanning. Treatment included consideration of middle
ear exploration for repair of a possible perilymphatic fistula, a short course of steroids, and
2 weeks of bed rest. Surgery was not performed. The patient’s vestibular symptoms
resolved and she had recovery of some of her hearing. She was fitted with a hearing aid
and counseled to avoid strenuous activities and contact sports. The patient also was
enrolled in a lip-reading class to improve her communication skills and to prepare her
for the possibility of future bilateral profound hearing loss. Note that patients with
progressive hearing loss of a severe to profound level, where hearing aids are no longer
helpful, can be managed effectively with cochlear implantation.

Teaching Points

1. Acoustic trauma refers to a single high-intensity acoustic event discharging near

an unprotected ear. Acoustic trauma can damage hair cells within the cochlea, thereby
causing an immediate and permanent sensorineural hearing loss that is typically
centered at 4 kHz. Mild and temporary vestibular symptoms are not unusual in cases
of acoustic trauma.
2. A temporary threshold shift is a transitory increase in auditory thresholds of 10 to
20 dB, primarily involving the mid to high frequencies. A temporary threshold shift
often occurs following sustained exposure to high-intensity noise. Associated
symptoms include high-pitched tinnitus and a sense of fullness in the ear. Vestibular
symptoms are not generally noted during temporary threshold shifts. The symptoms of a
temporary threshold shift are usually fully reversible over 12 to 24 hours and are thought
to be caused by an acute overconsumption of essential metabolic factors within the inner
ear. A permanent shift in hearing thresholds primarily affecting the high-frequency
range can occur following repeated temporary threshold shifts and is referred to as
noise-induced hearing loss.
3. Hearing loss discovered during childhood has many causes. The differential
diagnosis is summarized in Case 48: Table 1.
4. Inner ear dysplasia may present with sudden or progressive hearing loss in
childhood or young adulthood. The hearing loss can be unilateral or bilateral.
Vestibular symptoms are frequently noted but generally are mild, although acute
vertigo may occasionally be the most prominent symptom of an inner ear
malformation. A bump on the head, a strong sneeze, or straining during a bowel
movement may worsen the hearing or vestibular symptoms associated with inner ear
malformations. Inner ear dysplasias can also be associated with a perilymphatic fistula.
 CASE 48: CONGENITAL INNER EAR MALFORMATIONS 319

5. Inner ear malformations often include some degree of bony labyrinthine

abnormalities. They are easily detected and characterized by CT imaging. MRI scan
lacks the ability to visualize the bony detail necessary to characterize inner ear
malformations.
6. The enlarged vestibular aqueduct syndrome is a congenital malformation of the
temporal bone in which the vestibular aqueducts are abnormally enlarged. The
enlarged vestibular aqueduct syndrome predisposes children to develop progressive
sensorineural hearing loss and vestibular dysfunction at a relatively early age. An
abnormally large vestibular aqueduct can occur as an isolated finding or can accompany
more widespread congenital malformations of the cochlea and semicircular canals.
7. The mechanism of acoustic trauma-induced or barotrauma-induced otologic
dysfunction in patients with congenital inner ear malformations is unknown. In
addition to avoiding acoustic trauma and exposure to barotrauma, patients with
congenital inner ear malformations and their parents should be counseled concerning
avoidance of activities such as weightlifting, contact sports, or scuba diving. These
activities increase intrathoracic and cerebrospinal fluid pressure, thereby increasing the
likelihood of either rupture of inner ear membranes or the development of a
perilymphatic fistula.
8. Treatment for an acute worsening of hearing loss and acute vestibular symptoms
associated with congenital inner ear malformations should include consideration
of middle ear exploration, a short course of corticosteroids, and a period of
reduced activity and bedrest. Surgery directed at the endolymphatic sac should not
be performed.

References
1. Meyerhoff, WL, Cass S, Schwaber MK, Sculerati N, Slattery WH: Progressive sensorineural
hearing loss in children. Otolaryngol Head Neck Surg 110:569–579, 1994.
2. Frei K, Ramsebner R, Lucas T, Hamader G, Szuhai K, Weipoltshammer K, Baumgartner WD,
Wachtler FJ, Kirschhofer K: GJB2 mutations in hearing impairment: Identification of a broad
clinical spectrum for improved genetic counseling. Laryngoscope 115(3):461–465, 2005.
3. Groose SD, Ross DS, Dollard SC: Congenital cytomegalovirus infection as a cause of
permanent bilateral hearing loss: A quantitative assessment. J Clin Virol Oct. 22, 2007.
4. Brookhouse PE, Worthington DW, Kelly WJ: Noise-induced hearing loss in children.
Laryngoscope 102:645–655, 1992.
5. Supance JS, Bluestone CD: Perilymph fistulas in infants and children. Otolaryngol Head Neck
Surg 91:663–671, 1983.
6. Meyerhoff WL, Paperella MM, Shea D: Meniere’s disease in children. Laryngoscope
88:1504–1511, 1978.
7. Zagolski O: Vestibular system in infants with hereditary nonsyndromic deafness.Otol Neurol
28(8):1053–1055, 2007.
8. Shinjo Y, Jin Y, Kaga K: Assessment of vestibular function of infants and children with
congenital and acquired deafness using the ice-water caloric test, rotational chair test and
VEMP recordings. Acta Otolarynol 127(7):736–747, 2007.
9. Schuknecht HF: Mondi dysplasia: A clinical and pathological study, Part 2. Ann Otol Rhinol
Laryngol 89 (Suppl 65):3–23, 1980.
10. Jackler RK, De La Cruz A: The large vestibular aqueduct syndrome. Laryngoscope
99:1238–1243, 1989.
11. Parisier SC, Birken EA: Recurrent meningitis secondary to idiopathic oval window CSF
leak.Laryngoscope 86:1503–1515, 1976.
12. Jackler RK, Dillon WP: Computed tomography and magnetic resonance imaging of the inner
ear. Otolaryngol Head Neck Surg 99:494–504, 1988.
320 VESTIBULAR DISORDERS

13. Hirsch BE, Weissman JL, Curtin HD, Kamerer DB: Magnetic resonance imaging of large
vestibular aqueduct. Arch Otolaryngol Head Neck Surg 118:1124–1127, 1992.
14. Levenson MJ, Parisier SC, Jacobs M, Edelstein DR: The large vestibular aqueduct syndrome
in children. Arch Otolaryngol Head Neck Surg 115:54–58, 1989.
15. Madden C, Halsted M, Benton C, Greinwald J, Choo D: Enlarged vestibular aqueduct
syndrome in the pediatric population. Otol Neurotol 24(4):625–632, 2003.
16. Sugiura M, Sato E, Nakashima T, Sugiura J, Furuhashi A, Yoshino T, Nakayama A, Mori N,
Murakami H, Naganawa S: Long-term follow-up in patients with Pendred syndrome:
Vestibular, auditory and other phenotypes. Eur Arch Otorhinolaryngol 262(9):737–743, 2005.
17. Usami S, Abe S, Weston MD, Shinkawa H, Van Camp G, Kimberling WJ: Non-syndromic
hearing loss associated with enlarged vestibular aqueduct is caused by PDS mutations. Hum
Genet 104(2):188–192, 1999.
Case 49
Saccadic Fixation Instability

History

A 55-year-old man who worked as a shopkeeper complained of poor vision, especially

when shifting his gaze from one point to another, constant disequilibrium, some tremu-
lousness, palpitations for 6 weeks, and a recent weight loss of several pounds. There was no
complaint of hearing loss or tinnitus. The patient had no medical history or family history
of significance. He had recently been evaluated by his primary care physician, who could
not establish a diagnosis. That evaluation included normal routine blood studies, a normal
chest x-ray, and a normal electrocardiogram.

Physical Examination

The patient’s general examination demonstrated a fine tremor of the head and limbs. He
had a blood pressure of 150/100 and a heart rate of 95, with a regular rate and rhythm. The
patient had no significant change in blood pressure or heart rate after standing for 3 and 5
minutes. His neurologic examination revealed full extraocular movements. He had no
nystagmus. However, horizontal conjugate ocular flutter was noted. It occurred in bursts
lasting for 1 to 2 seconds. These bursts of small left and right saccades typically occurred
immediately following refixation of gaze. The patient had normal strength and sensation.
There was mild limb dysmetria on heel-knee-shin and finger-to-nose testing. The patient’s
gait was wide based, and he could not walk without assistance. Romberg’s test could not be
performed because the patient could not stand without assistance with the feet together.
Otologic examination was normal. Dix-Hallpike maneuvers were negative.
Question 1: What is ocular flutter? Are there other types of saccadic eye movement
abnormalities? How does opsoclonus differ from ocular flutter?
Answer 1: Ocular flutter, unlike nystagmus, consists of a to-and-fro movement of the
eyes wherein both components are rapid, that is, saccadic. Whereas nystagmus is
defined as a to-and-fro movement of the eyes wherein at least one of the directions
of movement is slow (less than about 40 degrees per second), in saccadic fixation
instabilities, of which ocular flutter is one type, both leftward and rightward move-
ments are rapid. Saccadic fixation instabilities include ocular flutter, opsoclonus,
square-wave jerks, macro-square-wave jerks, and macrosaccadic oscillations1–3
(Case 49: Table 1).

321
322 VESTIBULAR DISORDERS

Case 49: Table 1 Types of Saccadic Fixation Instabilities in Order of Severity

Category Characteristics and Associated Ocular Possible Pathophysiologic Substrate

Motor Findings

Square-wave Small saccades (0.5–5 degrees) away Can be normal, especially in the elderly.
jerks from fixiation and back with a 200– Common in cerebellar disease and
millisecond intersaccadic interval. progressive supranuclear palsy.
Macro-square- Saccadic intrusions (5–15 degrees) Multiple sclerosis and
wave jerks that take the eye away from fixation livopontocerebellar atrophy.
and return it within 70–150
milliseconds.
Macrosaccadic Oscillations around the fixation point Lesions of dorsal vermis and fastigial
oscillations that wax and wane. nucleus.
Intersaccadic interval of 200
millliseconds.
Ocular flutter Intermittent bursts of horizontal Unknown, possibly fastigial nucleus,
oscillations without an intersaccadic omnipause neurons or glycinergic
interval. mechanisms.
Opsoclonus Combined horizontal, vertical, and
torsional oscillations without an
intersaccadic interval.
Source: Adapted with permission from Leigh RJ, Zee DS: The Neurology of Eye Movements, ed 4. New York: Oxford University
Press, 2006, p 522.1

Whereas ocular flutter is limited to horizontal eye movements, opsoclonus

includes horizontal, vertical, and torsional saccades that may occur separately or
in combination such that the eyes move in quite erratic patterns. As with ocular
flutter, the intersaccadic interval in opsoclonus is brief or absent. Opsoclonus is
considered a more severe form of saccadic fixation instability than ocular flutter.
Some patients show different forms of saccadic fixation instabilities at different
times in their illness. For example, ocular flutter can occur while a patient is
recovering from opsoclonus.
Question 2: Based on the history and physical examination, what is the localization of this
patient’s problem?
Answer 2: Some of the patient’s complaints are consistent with a vestibular abnorm-
ality. However, his tremulousness and weight loss, coupled with the finding of ocular
flutter on physical examination, suggest a central abnormality. The patient’s incoor-
dination and severe gait instability strongly suggest that his problem includes an
abnormality in the cerebellum. The ocular flutter suggests an abnormality in the
pons, because this is the region of the brain important for the generation of saccadic
eye movements. The pons, however, receives powerful input from the cerebellum
that may be used to trigger saccadic eye movements. In this way, a cerebellar
abnormality can manifest itself as the abnormal occurrence of normally appearing
saccadic eye movements. The patient’s complaint of positional vertigo is unexplained.
Question 3: What are the diagnostic considerations for this patient?
Answer 3: The differential diagnosis for saccadic fixation instability is given in Case
49: Table 2. The subacute onset of saccadic fixation instability can be caused by
structural abnormalities of the pons or cerebellum, a viral brainstem encephalitis or
 CASE 49: SACCADIC FIXATION INSTABILITY 323

Case 49: Table 2 Causes of Saccadic Fixation Instability

Viral encephalitis
Neuroblastoma in paraneoplasia
Paraneoplasia
Trauma (sometimes in association with hypoxia and sepsis)
Meningitis
Intracranial tumors
Hydrocephalus
Thalamic hemorrhage
Multiple sclerosis
Hyperosmolar coma
Viral hepatitis
Sarcoid
Acquired immune deficiency syndrome
Side effects of medications: lithium, amitriptyline, phenytoin plus diazepam, phenelzine plus
imipramine
Toxins: chlordecone, thallium, strychnine, toluene, organophosphates
Pregnancy
Transient phenomenon of healthy neonates
Source: Adapted with permission from Leigh RJ, Zee DS: The Neurology of Eye Movements, ed 4. New York: Oxford
University Press, 2006, p. 525.1

cerebellitis, or a paraneoplastic syndrome. Some toxic agents and medications

have been reported to cause saccadic fixation instability, but these would
probably cause an acute onset of symptoms. Paraneoplastic-related saccadic
fixation instability, typically in the form of opsoclonus, has been seen with
carcinoma of the lung, especially oat cell carcinoma; carcinoma of the breast,
especially ductal carcinoma; and uterine carcinoma. In children, saccadic fixation
instabilities, typically in the form of opsoclonus, are seen with postviral encephalitis
and with neuroblastoma.4
Question 4: What additional laboratory testing would help in establishing the cause of this
patient’s condition?
Answer 4: Quantitative laboratory testing could further elucidate whether the
patient is suffering from a vestibular abnormality and document the ocular flutter.
MRI of the brain is critical to rule out structural disorders. Because this patient may
be suffering from a paraneoplastic syndrome, laboratory testing, including CT or
MRI of the chest, should include a search for a remote carcinoma, especially of the
lung. A lumbar puncture may uncover a viral meningoencephalitis. Blood studies
should include anti-Ri, anti-Yo and, anti-Hu antibody titers.

Laboratory Testing

Videonystagmography: Ocular motor testing revealed the presence of ocular flutter. Also,
the patient had difficulty tracking a slowly moving target. There was a left-reduced
vestibular response on caloric testing.
Rotational testing revealed a left-directional preponderance.
An MRI scan of the brain was normal.
324 VESTIBULAR DISORDERS

A search for a remote carcinoma, including antibody studies, a complete blood count
and differential, urinalysis, and chest CT was negative. Cerebrospinal fluid examination
was normal.

Diagnosis/Differential Diagnosis

Question 5: Based on the additional information from laboratory testing, what is this
patient’s likely diagnosis?
Answer 5: Laboratory testing suggested both an ocular motor abnormality, namely,
ocular flutter, and a vestibular system abnormality. Imaging studies revealed no
structural abnormality. The two most likely diagnoses of this patient’s condition are
the remote effects of a non–central nervous system neoplasm, that is, a paraneo-
plastic disorder, or a viral brainstem-cerebellar encephalitis. A toxic exposure is
unlikely considering the lack of an appropriate history.
Question 6: What is the underlying pathophysiologic mechanism for saccadic fixation
instability, and how does it differ from the mechanism for the generation of nystagmus?
Answer 6: Saccadic fixation instabilities are presumably caused by an abnormality of
the saccadic generation circuitry. The paramedian pontine reticular formation is
particularly important for the generation of horizontal saccades. The saccadic eye
movement generation circuitry contains several types of cells, including the burst
cells that fire during a saccade and the pause cells that are active between saccades
but shut off during saccades. The pause cells are thought to inhibit saccades.
Presumably, inappropriate saccades occur when pause cells in the pons stop inap-
propriately, allowing a rapid, that is, saccadic, eye movement to occur.5 Because
this triggering mechanism is premotor and does not involve the neural mechanism
for generating conjugate eye movements, saccades caused by inappropriate pause
cell behavior have normal velocity and are conjugate, even though they occur
spontaneously at unwanted times. Also, the obligatory refractory period between
two voluntary saccades (about 200 milliseconds) is violated by abnormal pause cell
behavior. Whether saccadic fixation instabilities are a result of abnormal function of
the pause cells themselves or of the triggers to the pause cells is uncertain.
The patient was given the diagnosis of ocular flutter of undetermined etiology. A
viral infection of the central nervous system or a paraneoplastic syndrome were
both considered possibilities, despite negative laboratory studies. Additionally, the
patient had a vestibular imbalance of uncertain etiology.

Treatment/Management

There is no specific treatment for ocular flutter.6

In the hope of reducing the central nervous system inflammatory response, the patient
was treated with prednisone, 60 mg daily for 2 weeks, followed by a gradually tapering
dose. He had significant symptomatic recovery, with reduction of tremulousness and
resolution of the ocular flutter. He was enrolled in a vestibular rehabilitation program for
gait and balance training, with gradual resolution of his imbalance. One year after pre-
sentation, the patient was asymptomatic. Despite this positive response to steroid therapy,
the patient should be followed closely since subsequent manifestation of a tumor remote
from the nervous system is possible.7
 CASE 49: SACCADIC FIXATION INSTABILITY 325

Summary

A 55-year-old man presented with a 6-week history of dizziness, disequilibrium, and

tremulousness. Physical examination revealed ocular flutter in addition to mild limb
dysmetria and ataxic gait. Vestibular laboratory studies disclosed a vestibular asymmetry
in addition to the saccadic instability. A definitive diagnosis could not be reached, but a
viral syndrome or a remote effect of carcinoma was suspected. The patient was treated with
prednisone. Symptoms resolved, and the patient’s balance improved during the subsequent
3 to 6 months. At 1-year follow-up, the patient was asymptomatic.

Teaching Points

1. Saccadic fixation instabilities, unlike nystagmus, consist of a to-and-fro eye

movement wherein both components are rapid, that is, saccadic. With nystagmus,
at least one of the directions of movement is slow, that is, less than about 40 degrees per
second. Saccadic fixation instabilities include ocular flutter, opsoclonus, square-wave
jerks, macro-square-wave jerks, and macrosaccadic oscillations (Case 49: Table 1).
2. Opsoclonus, which includes horizontal, vertical, and torsional saccades, is the most
severe form of saccadic fixation instability. Ocular flutter, a purely horizontal form of
saccadic fixation instability, is less severe and may occur while a patient is recovering
from opsoclonus.
3. Causes of ocular flutter and opsoclonus include structural abnormalities of the
pons or cerebellum, brainstem encephalitis or cerebellitis, a paraneoplastic
syndrome, and several toxic agents and medications. In children, saccadic fixation
instabilities, typically in the form of opsoclonus, can be seen with viral or postviral
encephalitis and with neuroblastoma.
4. The pathophysiology of saccadic fixation instability is an abnormality of the
saccadic generation circuitry.

References
1. Leigh RJ, Zee DS: The Neurology of Eye Movements, ed 4. New York: Oxford University
Press, 2006.
2. Sharpe JA, Fletcher WA: Saccadic intrusions and oscillations. Can J Neurol Sci 11:426–433,
1984.
3. Abel LA, Traccis S, Dell’Osso L, Daroff R, Troost B: Square wave oscillation.
Neuroophthalmology 4:21–25, 1984.
4. Digre KB: Opsoclonus in adults. Arch Neurol 43:1165–1175, 1986.
5. Zee DS, Robinson DA: A hypothetical explanation of saccadic oscillations. Ann Neurol
5:405–414, 1979.
6. Strupp M, Brandt T: Pharmacological advances in the treatment of neuro-otological and eye
movement disorders. Current Opinion in Neurology 19(1):33–40, 2006.
7. Furman JM, Eidelman BH, Fromm GH: Spontaneous remission of paraneoplastic saccadic
fixation instability. Neurology 38:499–501, 1988.
Case 50
Congenital Nystagmus

History

A 49-year-old man presented with a chief complaint of dizziness for 5 years. The patient
had daily symptoms that were characterized by a sense of lightheadedness, difficulty
focusing his vision, a sense of movement just after turning his head, and poor balance
while walking. He stated that his symptoms had been particularly noticeable since a head
injury sustained 1 year ago while working as a corrections officer. The patient had no
complaints of vertigo, positional sensitivity, hearing loss, or tinnitus. His history was
significant for 10 years of high blood pressure, for which he was under the care of a
physician. The family history was noncontributory.
Question 1: Based on the patient’s history, what are the diagnostic considerations? What
further historical information should be obtained?
Answer 1: This patient’s complaints suggest a vestibular system abnormality. There
are features that suggest both peripheral (e.g., illusory motion) and central nervous
system (e.g., chronic imbalance) involvement. The patient’s long course of symptoms
suggests either a chronic stable condition or a slowly progressive abnormality. The
role of the head trauma sustained 1 year earlier is uncertain. Additional information
on the patient’s head trauma would be useful, as well as information about any
prior evaluations for dizziness because his problem is long-standing.

Additional History

The patient related that the head trauma he suffered 1 year before evaluation was minor.
Evidently, he was pushed to the ground and struck his head against a wall, but he did
not lose consciousness and was able to stand and to return to work immediately. He did
note, however, a worsened problem with balance following that episode. He was
evaluated by his primary care physician, who was uncertain about the cause of the
patient’s disequilibrium but noted unusual eye movements. His physician ordered a CT
scan of the head, which was normal, and prescribed meclizine, which was of no benefit
to the patient.

326
 CASE 50: CONGENITAL NYSTAGMUS 327

Physical Examination

The patient had full extraocular movements but had a primary position nystagmus that did
not have clearly defined fast and slow components. The nystagmus appeared to be
irregular, with both fast and slow components to the right and to the left. With infrared
goggles, the nystagmus did not change. On horizontal gaze deviation, the patient had a
typical gaze-evoked nystagmus, which was also seen on upward gaze but not on downward
gaze. In fact, on downgaze, the nystagmus diminished somewhat. The patient was unable to
follow a target smoothly. The remainder of the cranial nerve examination was normal. The
patient’s motor, sensory, and coordination examinations were normal. Romberg’s test was
negative. Gait was slightly wide based and slow. Otologic examination was normal. The
head thrust test could not be interpreted because of nystagmus with the eyes open in the
light. The patient could stand on a foam pad without falling even with his eyes closed.
Question 2: Based on the history and physical examination, what is this patient’s likely
diagnosis and what further information would be helpful?
Answer 2: This patient’s examination revealed unusual eye movements. It would be
helpful to know how long these movements have existed. Moreover, since this
condition may represent congenital nystagmus, it would be helpful to assess the
influence of convergence because most patients with congenital nystagmus will
have a reduction in the amplitude of the nystagmus with convergence. An oculo-
graphic recording of the patient’s nystagmus might help determine its origin. A
vestibular laboratory evaluation might help uncover the basis for the patient’s
complaints of dizziness.

Additional History and Additional Physical Examination

Information

The patient was unaware of his nystagmus but said that as a child he was evaluated by an
ophthalmologist for ‘‘jumpy eyes.’’ With convergence, his nystagmus decreased in amplitude.

Laboratory Testing

Videonystagmography: Ocular motor testing revealed nystagmus in the primary position

during visual fixation that had an unusual pattern. There were no clearly defined quick and
slow components, but a repeating complex pattern was observed. The nystagmus was
unchanged with the eyes open in darkness. With horizontal gaze deviation, the patient
developed gaze-evoked nystagmus. He was unable to track a slowly moving target
smoothly. Optokinetic nystagmus was severely impaired, without clearly defined nystag-
mus. During positional testing, the nystagmus persisted without change. Caloric testing
revealed bilaterally reduced responses with about 5 degrees per second peak velocity of
nystagmus during each irrigation of a binaural bithermal caloric testing sequence.
Rotational testing revealed reduced responses with extremely abnormal dynamics, that
is, a large phase lead and a short time constant of only about 5 seconds.
Vestibular-evoked myogenic potentials were markedly reduced on the right and normal
on the left.
328 VESTIBULAR DISORDERS

Diagnosis/Differential Diagnosis

Question 3: What is this patient’s diagnosis, and what is the significance of the laboratory
tests? What role did the patient’s head trauma play in the generation of his symptoms?
Answer 3: The patient’s laboratory study results are consistent with congenital
nystagmus, the characteristics of which are listed in Case 50: Table 1. This patient
had many of the typical features, although there was no null region; that is, there
was no direction of gaze wherein the nystagmus was minimal. Vestibular studies
suggested bilateral vestibular loss. However, the vestibulo-ocular studies also
demonstrated abnormal VOR dynamics. Because congenital nystagmus is usually
associated with abnormalities of the VOR even in the absence of dizziness,1–3 it is
impossible to say whether the reduced VOR was a feature of the patient’s congenital
nystagmus, a sign of vestibular abnormality, or in any way related to the head
trauma. The abnormal vestibular-evoked potentials, however, suggest a right per-
ipheral vestibular abnormality. The history suggests that the patient suffered from a
labyrinthine concussion related to the head trauma suffered 1 year before evaluation.
The history also suggests some exacerbation of the patient’s underlying disability from
the head trauma possibly related to a brainstem concussion. His abnormal eye move-
ments complicate interpretation of both the physical examination and the laboratory
test abnormalities. Possibly, the patient’s ability to compensate for his peripheral
vestibular injury was impaired by a central nervous system abnormality, one of whose
manifestations was congenital nystagmus.
This patient was given the diagnoses of congenital nystagmus and a labyrinthine
concussion.
Question 4: What is pendular nystagmus? What are its subtypes?
Answer 4: Jerk nystagmus, by definition, has clearly defined fast and slow compo-
nents; pendular nystagmus, by definition, is a to-and-fro movement of the eyes
without a clearly defined quick movement direction. By convention, the direction
of jerk nystagmus is named for the direction of the quick movement, because this is
what is most apparent clinically. There are numerous varieties of jerk nystagmus.
Defining features include direction, influence of gaze, conjugacy, effect of visual
fixation, and waveform.
Pendular nystagmus may be congenital or acquired. Congenital pendular nystag-
mus is known simply as congenital nystagmus, whereas acquired pendular nystagmus,
which is very unusual, is called just that. Pendular nystagmus is more or less sinusoidal,
but it can have an unusual pattern such as that of this patient, whose pendular
nystagmus had a pseudoperiodic waveform.

Case 50: Table 1 Characteristics of Congenital Nystagmus

Present since infancy

Irregular waveforms
Conjugate
Almost always horizontal
Accentuated by fixation, attention, and anxiety
Decreased by convergence and active eyelid closure
Often a null region
No complaint of oscillopsia
Occasionally inverted optokinetic nystagmus
 CASE 50: CONGENITAL NYSTAGMUS 329

The underlying pathophysiology of pendular nystagmus, congenital or

acquired, is unknown. Patients with congenital (pendular) nystagmus have
abnormalities of gaze-holding mechanisms that manifest as gaze-evoked nystag-
mus and abnormalities of ocular tracking. Patients with congenital nystagmus also
have abnormal VOR dynamics.1–3
Acquired pendular nystagmus has been seen in patients with many disorders,
including multiple sclerosis, and in those with brainstem infarctions. Although
congenital nystagmus is almost always horizontal, acquired pendular nystagmus
often has nonhorizontal components and may even be elliptical, presumably as a
result of simultaneous horizontal and vertical pendular oscillations.4 Although con-
genital nystagmus is often associated with excellent visual acuity, presumably
because the pattern of eye movement allows brief periods of visual fixation,
acquired pendular nystagmus is typically associated with oscillopsia and poor
vision. Acquired pendular nystagmus is typically unaffected by visual fixation.
A variant of acquired pendular nystagmus, often purely vertical, is an oscillation
of the eyes that can be seen in association with palatal myoclonus as a result of
interruption of the so-called Mollaret’s triangle, which includes the fiber pathways
linking the inferior olive, the dentate nucleus, and the red nucleus.5 Pendular
nystagmus should not be confused with saccadic oscillations, which are discussed
elsewhere (see Case 49).

Treatment/Management

There is no specific treatment for congenital nystagmus. Several medications have been
tried, with limited success, as have optical and surgical remedies,4,6,7 also with limited
success. Based on the possibility that this patient had a vestibular system imbalance that
could not be adequately assessed because of his congenital nystagmus, a course of
vestibular rehabilitation was instituted. This had little effect on the patient’s condition or
complaints. A vestibular-suppressant medication was prescribed. This, too, was not ben-
eficial. The patient continued working but planned to take early retirement.

Summary

A 49-year-old man complained of long-standing disequilibrium that worsened following

minor head trauma. Examination revealed pendular nystagmus that was diminished by
convergence. A diagnosis of congenital nystagmus was made. Vestibular laboratory testing
also suggested abnormal VOR dynamics and a reduced magnitude of responses. The
vestibular laboratory test abnormalities may have been the result of congenital nystagmus
rather than peripheral vestibular dysfunction. The patient’s worsening balance following
minor head trauma may have been a result of labyrinthine concussion, but this could
neither be confirmed nor ruled out. Treatment with both balance therapy and vestibular-
suppressant medication was unsuccessful.

Teaching Points

1. Pendular nystagmus, a to-and-fro movement of the eyes without a clearly defined

quick movement direction, differs from jerk nystagmus, which has clearly defined
330 VESTIBULAR DISORDERS

fast and slow components. Pendular nystagmus may be congenital or acquired.

Congenital pendular nystagmus is known simply as congenital nystagmus. Pendular
nystagmus usually has an unusual, somewhat repetitive pattern.
2. Congenital nystagmus differs from acquired pendular nystagmus. Congenital
pendular nystagmus is almost always horizontal. Acquired pendular nystagmus
often has both horizontal and nonhorizontal components. Also, although congenital
nystagmus is often associated with excellent visual acuity, presumably because the
pattern of eye movement allows brief periods of visual fixation, acquired pendular
nystagmus is typically associated with oscillopsia and poor vision.
3. The pathophysiology of pendular nystagmus, whether congenital or acquired, is
unknown. Abnormalities associated with congenital (pendular) nystagmus include
poor gaze holding, poor ocular tracking, and a diminished VOR.

References

1. Carl JR, Optiacan LM, Chu FC, Zee DS: Head shaking and vestibulo-ocular reflex in
congenital nystagmus. Invest Ophthalmol Vis Sci 26:1043–1050, 1985.
2. Demer JL, Zee DS: Vestibulo-ocular and optokinetic deficits in albinos with congenital
nystagmus. Invest Ophthalmol Vis Sci 25:739–745, 1984.
3. Gresty MA, Barratt HJ, Page NG, Ell JJ: Assessment of vestibulo-ocular reflexes in congenital
nystagmus. Ann Neurol 17:129–136, 1985.
4. Leigh JR, Zee DS (eds): The Neurology of Eye Movements, ed 4. New York: Oxford
University Press, 2006.
5. Nakada T, Kwee I: Oculopalatal myoclonus. Brain 109:431–441, 1986.
6. Yee C, Baloh R, Honrubia V: Effect of Baclofen on congenital nystagmus. In: Lennerstrand G,
Zee D, Keller E (eds). Functional Basis of Ocular Motility Disorders. Oxford: Pergamon
Press, 1982, pp 151–158.
7. Hertle RW, Yang D: Clinical and electrophysiological effects of extraocular muscle surgery
on patients with Infantile Nystagmus Syndrome (INS). Seminars in Ophthalmology,
21(2):103–110, 2006.
Case 51
Otosclerotic Inner Ear
Syndrome

History

A 47-year-old female social worker reported dizziness for 6 months. The dizziness had
been quite variable, consisting of one major episode of vertigo 3 months earlier associated
with nausea and vomiting that lasted for hours and several minor episodes of vertigo lasting
for seconds. Between episodes, the patient noticed daily dizziness that was worsened by
rapid head movements. She also noticed some unsteadiness and veering of her gait to the
left, especially in darkness.
The patient also reported a bilateral hearing loss, first noticed at age 25, which had been
slowly progressive in both ears. There was no fluctuation of hearing and no aural fullness.
A bilateral low-pitched roaring sound, worse in the right ear, was present. There was no
medical history of otitis media, noise exposure, or trauma. The family history was positive
for hearing loss in her mother and two maternal aunts.

Physical Examination

General and neurologic examinations were normal, except that the patient’s casual walking
was slow. Tandem walking was performed with slight difficulty. Romberg’s test was
negative. Otoscopy was normal. Tuning fork examination using a 512 Hz fork revealed
lateralization to the right on Weber’s test; the Rinne test was negative (bone conduction
was greater than air conduction) bilaterally.
Question 1: What is the most likely cause of this patient’s hearing loss?
Answer 1: The Rinne tuning fork examination suggests the presence of a bilateral
conductive hearing loss. The result of Weber’s test suggests either that the con-
ductive hearing loss is slightly greater on the right or that a combined conductive
and sensorineural hearing loss is present on the left. The finding of a conductive
hearing loss, with no previous history of otitis media or trauma and a normal
otoscopic examination, suggests a diagnosis of otosclerosis. The positive family
history of hearing loss reinforces this diagnosis.

331
332 VESTIBULAR DISORDERS

Question 2: What is otosclerosis?

Answer 2: Otosclerosis is a localized disease of bone remodeling involving the otic
capsule. The abnormal remodeling begins with resorption of stable otic capsule bone
in adults, followed by a reparative phase with bone deposition known as sclerosis.
Conductive hearing loss develops when otosclerotic foci invade the stapedial liga-
ment in the oval window and interfere with free motion of the stapes, causing
conductive hearing loss. Sensorineural hearing loss may also occur if otosclerotic
foci invade the cochlear duct or internal auditory canal.
Question 3: What pathologic changes are seen in the inner ear in otosclerosis?
Answer 3: Otosclerotic bone occurs when the original endochondral bone of the
bony labyrinth is destroyed and replaced by highly cellular fibrous tissue. This
fibrous tissue contains abundant lysosomes containing hydrolytic enzymes that are
thought to be involved in bone resorption. After destruction of the endochondral
bone, bony remodeling and production of immature otosclerotic bone occur.
Repetition of the remodeling process results in areas of otosclerotic bone that often
contain both inactive and active regions of bony remodeling. About 85% of
otosclerotic foci are located in the oval window regions. This process of bony
remodeling often results in fixation of the stapes footplate and progressive con-
ductive hearing loss. As normal bone is replaced by otosclerotic bone, the original
anatomic configuration of the bony labyrinth is usually preserved. Actual invasion of
the labyrinthine spaces is rare and occurs only in the most active lesions.
Question 4: Is otosclerosis a common disorder?
Answer 4: Clinically diagnosed otosclerosis has an estimated incidence of 0.5% to
1% in the adult Caucasian population, making it the single most common cause of
hearing impairment in this population. The incidence of subclinical otosclerosis,
that is, otosclerosis found in the temporal bones of individuals without symptoms
during life, ranges from 8% to 12%. In African Americans, otosclerosis is found in
only 1% of temporal bones and has a clinical incidence of only 0.1%. The disease is
rare to nonexistent in Asians and Native Americans. There is a female-to-male ratio
of clinical otosclerosis of about 2:1.1
Question 5: What is the cause of otosclerosis?
Answer 5: Families with autosomal dominantly inherited otosclerosis have been
described, but in most patients the etiology of the disease is unknown. There are
multiple lines of evidence that persistent measles virus infection together with an
underlying hereditary predisposition may lead to the development of clinical
otosclerosis. Autoimmunity as a potential etiologic factor is also supported by
some experimental evidence but its overall role remains unclear.2

Laboratory Testing

Videonystagmography: Ocular motor function was normal. A low-amplitude left-beating

spontaneous vestibular nystagmus was noted. There was no positional nystagmus. Caloric
testing revealed a significant right reduced vestibular response.
Rotational testing revealed responses of normal amplitude and timing with a significant
left directional preponderance.
Posturography was normal.
 CASE 51: OTOSCLEROTIC INNER EAR SYNDROME 333

Case 51: Figure 1 Audiogram

An audiogram was performed and showed a bilateral mixed conductive and sensor-
ineural hearing loss (Case 51: Figure 1). The sensorineural component of the hearing loss
was mild, ranging from 20 dB in the low frequencies to 30 dB in the high frequencies. The
conductive component of the hearing loss produced a 40 to 50 dB hearing loss primarily
affecting the lower frequencies in each ear. The conductive hearing loss was slightly
greater in the right ear.
VEMPs were not performed because of the conductive hearing loss.
Question 6: This patient reported tinnitus, and the audiogram showed mild sensorineural
hearing loss. Are these symptoms and findings commonly associated with otosclerosis, a
disorder that primarily affects conduction of sound through the middle ear?
Answer 6: Although conductive hearing loss is the most common manifestation
of otosclerosis, tinnitus is also very common and may be related to either
fixation of the stapes or damage to the sensorineural elements of the cochlea.
Sensorineural hearing loss is also frequently associated with otosclerosis. If
sensorineural hearing loss is present, it is most commonly seen in combination
with stapes fixation, which presumably causes a mixed conductive and sensor-
ineural hearing loss. Occasionally, patients present with pure cochlear oto-
sclerosis, that is, sensorineural hearing loss without a conductive component.
Establishing that a sensorineural hearing loss is the result of otosclerosis is
difficult but should be suspected in patients with a family history of otosclero-
sis. It is also possible to detect the presence of abnormal otosclerotic bone
surrounding the inner ear on high-resolution CT imaging of the temporal
bone.3
334 VESTIBULAR DISORDERS

Question 7: Is dizziness commonly associated with otosclerosis? Are vestibular abnorm-

alities common?
Answer 7: Vestibular symptoms are more common in individuals with otosclerosis
than in the general population. The reported prevalence of dizziness in individuals
with otosclerosis ranges from 7% to 40%.4–6 Unilateral or bilateral reduced caloric
function has been observed in up to 60% of otosclerotic patients reporting vertigo.6
It has also been suggested that the incidence of vestibular symptoms correlates with
the presence of an associated sensorineural hearing loss.6,7

Question 8: What is the cause of dizziness associated with otosclerosis?

Answer 8: Dizziness in patients with otosclerosis may be caused either by the co-
occurrence of a disorder other than otosclerosis, such as Meniere’s disease or
migraine, or by the pathologic process of otosclerosis itself, which can produce
vestibular symptoms as a result of the otosclerotic inner ear syndrome discussed
below. Surprisingly, the otosclerotic inner ear syndrome appears to occur less
frequently than combined otosclerosis and Meniere’s disease.5
The combination of Meniere’s disease and otosclerosis has been reported by a number
of authors8,9 and has also been confirmed by temporal bone histopathology.10 The clinical
diagnosis of combined Meniere’s disease and otosclerosis is based on the findings of a low-
frequency sensorineural hearing loss, fluctuation of hearing, aural fullness, and vertigo,
that is, a symptom complex typical of endolymphatic hydrops.5,8 An etiologic connection
between otosclerosis and migraine has been proposed but remains uncertain.9
The pathophysiology underlying the otosclerotic inner ear syndrome is uncertain.
One proposed mechanism of vestibular injury caused by otosclerosis involves the
encroachment of the cribriform area of the vestibule by otosclerotic bone11 (Case 51:
Figure 2). The cribriform area is pierced by vestibular nerve fibers from the internal

(a) (b)

Case 51: Figure 2 Histopathology of otosclerosis. (A) Low-power view of temporal bone
showing a focus of otosclerotic bone bordering the cochlea and vestibule and infiltrating the
stapes footplate. Note the presence of abnormal vascular channels within the otosclerotic bone.
Open arrowheads5portion of cochlea bordered by otosclerosis; solid arrow5stapes footplate.
Source: Reprinted by permission of the publisher from Schuknecht HF: Pathology of the Ear. Cambridge,
MA: Harvard University Press. Copyright 1974 by the President and Fellows of Harvard College.
(B) High-power view of temporal bone showing otosclerotic encroachment of the lamina
cribosa (the region that transmits the vestibular nerve from the internal auditory canal to the
labyrinth). Thick arrow5lamina cribosa; arrowheads5vestibular nerve fibers.
This histology section was given by Dr. H. F. Schuknecht to the Eye and Ear Institute of Pittsburgh. The
temporal bone specimen from which this section was made belongs to the Massachusetts Eye and Ear
Infirmary, Boston.
 CASE 51: OTOSCLEROTIC INNER EAR SYNDROME 335

auditory canal that innervate the vestibular end organs within the inner ear.
Otosclerotic bone encroachment causes vestibular nerve degeneration, which has
been observed in temporal bone specimens. Histopathologic studies have also demon-
strated reduced cell counts in Scarpa’s ganglion without evidence of otosclerotic
encroachment of the cribriform areas, so other pathologic mechanisms are probably
involved.12 The otosclerotic inner ear syndrome seems to be more prevalent in
individuals with cochlear otosclerosis, and thus the two conditions may have a
common pathophysiology. The most popular theory of cochlear otosclerosis hypothe-
sizes the release of toxic proteolytic enzymes into the inner ear by active areas of
otosclerosis.13,14 This pathologic mechanism may also affect the vestibular portion of
the inner ear and result in symptoms of the otosclerotic inner ear syndrome.
Question 9: Are there any characteristic symptoms or signs of the otosclerotic inner ear
syndrome?
Answer 9: No. Historically the diagnosis of otosclerotic inner ear syndrome was
created to describe vertigo in a patient with otosclerosis whose audiovestibular
symptoms do not suggest Meniere’s disease or any other known vestibular syndrome.
Symptoms of otosclerotic inner ear syndrome can include episodic vertigo lasting for
20 minutes to 6 hours, vague feelings of floating or lightheadedness, and nonspecific
imbalance or disequilibrium.

Question 10: Why is it important to distinguish between vestibular system dysfunction

based solely on otosclerotic inner ear syndrome versus vestibular system dysfunction based
on combined Meniere’s disease and otosclerosis?
Answer 10: Surgical treatment of the conductive hearing loss associated with
otosclerosis is highly successful.15,16 Although there is no contraindication to
surgery for otosclerosis in an ear with the otosclerotic inner ear syndrome, surgery,
for whatever reason, in an ear affected by active Meniere’s disease is associated with
an increased incidence of profound hearing loss.
Question 11: Are there any other vertigo syndromes associated with conductive hearing loss?
Answer 11: Yes. Superior semicircular canal dehiscence (SCCD) (see Case 32) can
present with conductive hearing loss thus simulating otosclerosis.17,18 Keys to
distinguishing SCCD from otosclerosis include the presence of audiometric bone-
conduction thresholds better than 0 dB and intact acoustic reflexes found in SCCD
and not in otosclerosis. The character of vertigo in SCCD includes dizziness pro-
voked by sound (Tullio’s phenomenon) (see Case 32) or pressure (Hennebert
symptom). These symptoms are not found in otosclerotic inner ear syndrome.

Diagnosis/Differential Diagnosis

The patient was given the diagnosis of otosclerosis and otosclerotic inner ear syndrome.

Treatment/Management

The patient elected to undergo surgical correction of the conductive hearing loss in the right
ear. A stapedectomy was performed under local anesthesia and resulted in substantial
improvement in hearing and reduction of tinnitus. The vestibular symptoms remained
336 VESTIBULAR DISORDERS

unchanged. The patient requested surgical correction of hearing in her left ear, but this was
deferred for at least 6 months.
The presence of a sensorineural component of the hearing loss is suggestive of mild
cochlear otosclerosis. Historically, sodium fluoride supplementation has been proposed as
a treatment of cochlear otosclerosis. Sodium fluoride is thought to reduce the amount of
proteolytic enzymes released into the inner ear by an active focus of otosclerosis, thus
reducing the progression of sensorineural hearing loss. However, the lack of controlled
clinical trials, the potential complications (gastritis, skeletal fluorosis), and the cost of large
doses of sodium fluoride have limited its widespread use. In the future, bisphosphonates
(e.g., etidronate) are the most promising candidates for medical treatment of audiovestibular
effects due to cochlear otosclerosis. Orally administered bisphosphonates are incorporated
into bone and inhibit osteoclastic activity. These compounds are very well tolerated and may
be effective if given intermittently. Further clinical trials are necessary before these agents are
recommended for routine clinical use.2,19
The vestibular symptoms in this patient consisted of both episodic vertigo and daily
dizziness and unsteadiness associated with quick head movements. Vestibular rehabilitation
was recommended to improve the chronic movement-induced disequilibrium, and a vestibular
suppressant (promethazine, 25 mg orally twice a day) was provided on an as-needed basis to
treat nausea associated with the infrequent episodic spells of vertigo.

Summary

A 47-year-old woman presented with 6 months of dizziness. A long-standing bilateral

hearing loss was also a problem. The family history was significant for hearing loss. The
patient’s hearing loss was found to be primarily conductive, and a diagnosis of otosclerosis
was reached. Additionally, she had a sensorineural hearing loss and vestibular laboratory
test abnormalities that suggested the otosclerotic inner ear syndrome. The patient under-
went surgery for otosclerosis, which improved her hearing. Vestibular rehabilitation also
was ordered and provided the patient with improved balance.

Teaching Points

1. Otosclerosis is a disorder of the bony labyrinth that most commonly causes a

progressive stiffening and fixation of the stapes footplate by the formation of
abnormal otosclerotic bone.
2. Otosclerosis is a common disorder with a subclinical incidence of about 10% and a
clinical incidence of up to 1% in the Caucasian population. The incidence of
otosclerosis varies by ethnic background and is greatest in Caucasians, uncommon in
African Americans, and rare in Asians and Native Americans. There is a female-to-male
ratio of clinical otosclerosis of about 2:1. Families with autosomal dominantly inherited
otosclerosis have been described.
3. Otosclerosis causes a conductive hearing loss. The finding of a conductive hearing
loss with no previous history of otitis media or trauma and a normal otoscopic
examination suggests a diagnosis of otosclerosis. The presence of a conductive hearing
loss can be inferred clinically through the use of the Rinne and Weber tuning fork tests.
4. Tinnitus and sensorineural hearing loss may be associated with otosclerosis.
Cochlear otosclerosis (i.e., sensorineural hearing loss without a conductive
 CASE 51: OTOSCLEROTIC INNER EAR SYNDROME 337

component) can also occur but is difficult to diagnose. In suspected cases of cochlear
otosclerosis, CT imaging of the temporal bones can confirm the diagnosis.
5. Vestibular symptoms are more common in individuals with otosclerosis than in the
general population. The reported prevalence of dizziness in individuals with
otosclerosis ranges from 7% to 40%. Dizziness in patients with otosclerosis may be
caused by either the co-occurrence of a disorder other than otosclerosis, such as
Meniere’s disease, or by the pathologic process of otosclerosis itself, which can
produce vestibular symptoms as a result of the otosclerotic inner ear syndrome.
6. Otosclerotic inner ear syndrome is a term used to describe patients with vertigo and
otosclerosis whose audiovestibular symptoms do not suggest Meniere’s disease,
superior canal dehiscence syndrome, or any other known vestibular syndrome.
Symptoms of the otosclerotic inner ear syndrome can include episodic vertigo, vague
feelings of floating or lightheadedness, and nonspecific imbalance or disequilibrium.
7. Stapedectomy, the surgical treatment for conductive hearing loss associated with
otosclerosis, is highly successful. However, it is important to distinguish the
otosclerotic inner ear syndrome from combined Meniere’s disease and otosclerosis
because surgery in an ear affected by active Meniere’s disease is associated with an
increased incidence of profound hearing loss, whereas there is no contraindication to
surgery in patients with the otosclerotic inner ear syndrome alone.
8. Treatment for the otosclerotic inner ear syndrome is nonspecific. Occasionally,
patients report improvement of their vestibular symptoms following stapedectomy.
Treatment may include vestibular-suppressant medications as needed and vestibular
rehabilitation. Sodium fluoride supplementation has been advocated as a treatment for
progressive sensorineural hearing loss associated with cochlear otosclerosis. The
efficacy of sodium fluoride or bisphosphonates in the otosclerotic inner ear syndrome
has not been established.

References

1. Mackenzie M, Wolfenden N: Otosclerosis. J Laryngol Otol 69:437–456, 1955.

2. Chole RA, McKenna M: Pathophysiology of otosclerosis. Otol Neurotol 22(2):249–257,
2001.
3. Kawase S, Naganawa S, Sone M, Ikeda M, Ishigaki T: Relationship between CT densitometry with
a slice thickness of 0.5 mm and audiometry in otosclerosis. Eur Radiol 16(6):1367–1373, 2006.
4. Paparella MM, Chasen WD: Otosclerosis and vertigo. J Laryngol Otol 80:511–517, 1966.
5. McCabe BF: Otosclerosis and vertigo. Trans Pacific Coast Oto-Ophthalmol Soc Ann Meeting
47:37–42, 1966.
6. Cody DT, Baker HL: Otosclerosis: Vestibular symptoms and sensorineural hearing loss. Ann
Otol 87:778–796, 1978.
7. Morales-Garcia C: Cochleo-vestibular involvement in otosclerosis. Acta Otolaryngol
73:484–492, 1972.
8. Paparella MM, Mancini F, Liston SL: Otosclerosis and Meniere’s syndrome: Diagnosis and
treatment. Laryngoscope 94:1414–1417, 1984.
9. Shea JJ, Ge X, Orchik DJ: Endolymphatic hydrops associated with otosclerosis. Am J Otol
15:348–357, 1994.
10. Black FO, Sando I, Hildyard VH, Hemenway WG: Bilateral multiple otosclerotic foci and
endolymphatic hydrops. Ann Otol Rhinol Laryngol 78:1062–1073, 1969.
11. Sando I, Miller D, Hemenway WG, Black FO: Vestibular pathology in otosclerosis. Temporal
bone histopathological report. Laryngoscope 84(4):593–605, 1974.
12. Richter E, Schuknecht HF: Loss of vestibular neurons in clinical otosclerosis. Arch
Otorhinolaryngol 234:1–9, 1982.
338 VESTIBULAR DISORDERS

13. Lawrence M: Possible influence of cochlear otosclerosis on inner ear fluids. Ann Otol Rhinol
Laryngol 75:553–558, 1966.
14. Causse JR, Uriel J, Berges J, Shambaugh GE Jr, Bretlau P, Causse JB: The enzymatic
mechanism of the otospongiotic disease and NaF action on the enzymatic balance. Am J Otol
3:297, 1982.
15. Hillel AD: History of stapedectomy. Am J Otolaryngol 4:131–140, 1983.
16. Vincent R, Sperling NM, Oates J, Jindal M: Surgical findings and long-term hearing results in
3, 050 stapedotomies for primary otosclerosis: A prospective study with the otology-
neurotology database. Otol Neurotol (8 Suppl 2):S25–47, 2006.
17. Halmagyi GM, Aw ST, McGarvie LA, Todd MJ, Bradshaw A, Yavor RA, Fagan PA: Superior
semicircular canal dehiscence simulating otosclerosis. J Laryngol Otol 117(7):553–557, 2003.
18. Mikulec AA, McKenna MJ, Ramsey MJ, Rosowski JJ, Herrmann BS, Rauch SD, Curtin HD,
Merchant SN: Superior semicircular canal dehiscence presenting as conductive hearing loss
without vertigo. Otol Neurotol 25(2):121–129, 2004.
19. Brookler KH, Tanyeri H: Etidronate for the the neurotologic symptoms of otosclerosis:
Preliminary study. Ear Nose Throat J 76(6):371–376, 379–381, 1997.
Case 52
Solvent Exposure

History

A 30-year-old male welder presented with a chief complaint of dizziness after a mishap at
work 3 months before evaluation. The patient was welding inside a large tank that
previously had been used for storing industrial solvents. He was not wearing any breathing
protection. He remembers vaporizing some ‘‘goo.’’ Then he felt giddy and was observed by
fellow workers giggling and rolling in the snow outside the storage tank. The patient was
taken to a local emergency room, where no abnormalities were found. He experienced
persistent dizziness and disequilibrium characterized by a sense of lightheadedness and
worsened by head movement. The patient’s symptoms were also worsened by standing for
prolonged periods and by walking on uneven surfaces. He also complained of intolerance
to exposure to any solvents or household cleaning agents. The patient had no complaint of
hearing loss, tinnitus, or fullness or stuffiness of the ears. There was no positional
sensitivity. He had no prior history of dizziness or any other significant prior medical
history. The family history was noncontributory. The patient had undergone an extensive
evaluation before presentation because of the legal implications of the accident. The brain
imaging scan, blood studies, and audiometric test were normal.
Question 1: Based on the patient’s history, what is the likely diagnosis?
Answer 1: This patient is likely to have suffered from industrial chemical or solvent
exposure.1,2 The chance occurrence of any unrelated illness or exacerbation of a
preexisting condition is unlikely. He also seems to have acquired an intolerance to
solvents.3

Physical Examination

The general and otologic examinations were normal. Neurologic examination showed that
the patient had full extraocular movements with saccadic pursuit. There was bilateral
horizontal gaze-evoked nystagmus. The patient had a wide-based gait and an unsteady
tandem gait. Romberg’s test was normal. The remainder of the neurologic examination was
normal. With infrared goggles there was no nystagmus while seated, but on positional
testing he had a direction-changing positional nystagmus with left-beating nystagmus in
the head-left and left-lateral positions and right-beating nystagmus in the head-right and

339
340 VESTIBULAR DISORDERS

right-lateral positions. There was no paroxysmal positional nystagmus on Dix-Hallpike

maneuvers. He could not maintain balance on a foam pad with his eyes closed.

Laboratory Testing

Videonystagmography: Ocular motor and positional testing confirmed the abnormalities

seen during physical examination that included saccadic pursuit, bilateral horizontal gaze-
evoked nystagmus, and a direction-changing positional nystagmus. Additionally, the
patient could suppress his positional nystagmus with vision. There was a 35% left reduced
vestibular response on caloric testing.
Rotational testing revealed a mild right directional preponderance.
Posturography indicated excessive sway on all conditions in a nonspecific pattern.
Question 2: Based on the history, physical examination, and laboratory studies, what
structures are likely to be involved in this patient’s problem?
Answer 2: Some of this patient’s abnormalities, such as gaze-evoked nystagmus and
saccadic pursuit, suggest brainstem and cerebellar involvement, whereas peripheral
vestibular involvement (on the left) is suggested by a mildly reduced response on
caloric testing unilaterally. His posturography is nonlocalizing and thus does not
support or rule out a peripheral vestibular disorder. The patient’s directional pre-
ponderance on rotational testing suggests an ongoing vestibulo-ocular asymmetry
due either to impaired compensation for his peripheral vestibular disorder (see Case 3)
or to a central vestibular abnormality.
Question 3: What is the pathophysiology of direction-changing positional nystagmus, and
what is its localizing value?
Answer 3: Direction-changing positional nystagmus was once thought to be indica-
tive of a central nervous system disorder, but more recent studies have suggested that
direction-changing positional nystagmus can be caused by either a peripheral or a
central vestibular disorder.4 A well-recognized peripheral vestibular cause of direction-
changing positional nystagmus is acute ethanol intoxication. However, direction-
changing positional nystagmus that is not acute and not a result of ethanol cannot be
localized. Direction-changing positional nystagmus of peripheral vestibular origin,
either alcoholic or otherwise, is probably based on an inequality between the specific
gravity of the cupula of the horizontal semicircular canal and the specific gravity of
the surrounding endolymph.5 Such an inequality of specific gravity could result from
either a heavy cupula, a light cupula, or debris adherent to the cupula.
The most common cause of direction-changing positional nystagmus is an
inequality of the specific gravity of the horizontal semicircular canal cupula and
the surrounding endolymph caused by ethanol intoxication.6 So-called positional
alcohol nystagmus (PAN) occurs both early (about 30 minutes to 3 hours) and late
(about 4 to 13 hours) following the ingestion of ethanol. The presumed mechanism
relates to a difference in diffusion rates into and out of the horizontal semicircular
canal cupulae and the surrounding semicircular canal endolymph. Thus, in the early
stage of PAN (PAN I), the horizontal semicircular canal cupulae are light and ‘‘float’’
when the head is in the lateral, that is, the ear-down, position. The direction-
changing positional nystagmus of PAN I is geotropic, that is, left-beating in the left
lateral position and right-beating in the right lateral position. In the later stage of ethanol
intoxication the cupulae ‘‘sink,’’ thereby causing an ageotropic direction-changing
 CASE 52: SOLVENT EXPOSURE 341

positional nystagmus, PAN II. A less frequent but well-understood peripheral vestibular
cause of direction-changing positional nystagmus is that of horizontal semicircular
canal cupulolithiasis.7 This condition is thought to be caused by debris, possibly
degenerated otoconia, adherent to the horizontal semicircular canal cupula of either
the right or the left ear. Patients with this condition have a persistent ageotropic
positional nystagmus and, like patients with PAN, have a nystagmus that persists for
as long as a head-lateral position is maintained.
Well-documented cases of direction-changing positional nystagmus resulting
from central nervous system lesions have been described,8 but the underlying
pathophysiology for this association is unknown. Thus, this patient’s direction-
changing positional nystagmus may be based upon either central or peripheral
vestibular involvement.
Question 4: What are some of the industrial solvents known to cause vestibular system
impairment, and what is the pathophysiologic basis for this impairment?
Answer 4: Very little is known about industrial solvent exposure, including exactly
which chemicals are responsible and the underlying pathophysiology. However,
xylene, styrene, trichlorethylene, and methylchloroform are industrial agents
thought to be toxic to the vestibular system. The most consistent vestibular
abnormalities following exposure to these agents in animals are a persistent, that
is, a nonparoxysmal, positional nystagmus9 and impaired visual–vestibular interac-
tion.10–12 Other reported abnormalities include an increased VOR.13
The pathophysiology of the vestibular dysfunction seen in industrial solvent
exposure probably relates to central vestibular pathways, including the cerebellum.
The direction-changing positional nystagmus seen with solvent exposure is not
thought to be caused by a cupula-endolymph specific gravity mismatch (see
above), because the positional nystagmus can be blocked by the GABA agonist
baclofen.9
Chronic exposure to volatile hydrocarbons can cause chronic toxic encephalo-
pathy, which can be associated with abnormal visual–vestibular interaction and
abnormal smooth pursuit.14

Diagnosis/Differential Diagnosis

This patient was given the diagnosis of industrial solvent toxicity causing a combination of
peripheral and central vestibular disorders.

Treatment/Management

This patient was treated with a course of vestibular rehabilitation therapy. He was advised
to avoid exposure to all industrial solvents, including paint fumes and household cleaning
products. The patient was also advised to avoid situations that required balance for safety.
His symptoms improved somewhat, but he was unable to return to work as a welder.

Summary

A 30-year-old male welder was accidentally exposed to a vaporized mixture of industrial

solvents and became acutely dizzy. He gradually recovered but was left with a chronic
342 VESTIBULAR DISORDERS

imbalance. The patient was found to have objective evidence of a vestibular system
disorder, including direction-changing positional nystagmus, which is a nonlocalizing
abnormality. Other abnormalities, such as unilateral caloric reduction and an abnormal
ocular motor test, suggested impairment of peripheral and central vestibular structures,
respectively. The patient was treated with a course of vestibular rehabilitation therapy and
his symptoms decreased somewhat, but he could not return to work.

Teaching Points

1. Industrial solvents can cause vestibular system impairment. Xylene, styrene,

trichlorethylene, and methylchloroform are industrial agents thought to be toxic
to the vestibular system. The most consistent vestibular abnormality following
exposure to these agents is a persistent positional nystagmus.
2. The pathophysiology of industrial solvent—induced vestibular dysfunction is
unknown but probably involves central vestibular pathways including the cerebellum.
3. Treatment for industrial solvent—induced vestibular dysfunction is nonspecific.
Affected individuals should be advised to avoid subsequent exposure to all industrial
solvents, including paint fumes and household cleaning products, and to avoid
situations that require balance for safety. Vestibular rehabilitation may help promote
improved balance and adaptation to vestibular deficits.
4. Direction-changing positional nystagmus is a nonspecific, nonlocalizing sign.

References

1. Hodgson MJ, Furman J, Ryan C, Durrant J, Kern E: Encephalopathy and vestibulopathy

following short-term hydrocarbon exposure. J Occup Med 31:51–54, 1989.
2. Hodgkinson L, Prasher D: Effects of industrial solvents on hearing and balance: A review.
Noise & Health 8(32):114–133, 2006.
3. Gyntelberg F, Vesterhauge S, Fog P, Isager H, Zillstorff K: Acquired intolerance to organic
solvents and results of vestibular testing. Am J Ind Med 9:363–370, 1986.
4. Brandt T: Background, technique, interpretation, and usefulness of positional and positioning
testing. In: Jacobson GP, Newman CW, Kartush JM (eds). Handbook of Balance Function
Testing. St Louis: Mosby Year Book, 1993, pp 123–155.
5. Money K, Johnson W, Corlett R: Role of semicircular canals in positional alcohol nystagmus.
Am J Physiol 208:1065–1070, 1965.
6. Baloh RW, Honrubia V: Clinical Neurophysiology of the Vestibular System, ed 3. New York:
Oxford University Press, 2001.
7. Baloh RW, Yue Q, Jacobson KM, Honrubia V: Persistent direction-changing positional
nystagmus: Another variant of benign positional nystagmus? Neurology 45:1297–1301,
1995.
8. Lin J, Elidan, J Baloh RW, Honruba V: Direction-changing positional nystagmus: Incidence
and meaning. Am J Otolaryngol 7:306–310, 1986.
9. Odkvist LM, Larsby B, Fredrickson MF, Liedgren SR, Tham R: Vestibular and oculomotor
disturbances caused by industrial solvents. J Otolaryngol 9:53–59, 1980.
10. Niklasson M, Tham R, Larsby B, Eriksson B: Effects of toluene, styrene, trichloroethylene,
and trichloromethane on the vestibulo- and opto-oculo motor system in rats. Neurotoxicol
Teratol 15:327–334, 1993.
11. Hyden D, Larsby B, Andersson H, Odkvist LM, Liedgren SR, Tham R: Impairment of
visuo-vestibular interaction in humans. ORL J Otorhinolaryngol Relat Spec 45:262–269,
1983.
 CASE 52: SOLVENT EXPOSURE 343

12. Odkvist LM, Larsby B, Tham R, Ahlfeldt H, Andersson B, Eriksson B, Liedgren SR:
Vestibulo-oculomotor disturbances in humans exposed to styrene. Acta Otolaryngol
94:487–493, 1982.
13. Biscaldi GP, Mingardi M, Pollini G, Moglia A, Bossi MC: Acute toluene poisoning.
Electroneurophysiological and vestibular investigations. Toxicol Eur Res 3:271–273, 1981.
14. Odkvist LM, Moller C, Thuomas K-A: Otoneurologic disturbances caused by solvent
pollution. Otolaryngol Head Neck Surg 106:687, 1992.
Case 53
Wernicke’s Encephalopathy

History

A 54-year-old woman who did not work outside the home presented with a chief complaint
of 2 weeks of forgetfulness, ‘‘wandering eyes,’’ and very poor balance. The patient’s
history was significant for left hemiglossectomy and left radical neck dissection 6 months
before presentation for squamous cell carcinoma. The patient had no complaints of vertigo
or hearing loss and no tinnitus. There was no prior history of balance disorder. The family
history was negative.
Question 1: Based on the patient’s history, what are the diagnostic considerations? What
additional historical details should be obtained?
Answer 1: The patient’s history is consistent with a wide differential diagnosis that
includes a vestibular system abnormality because of imbalance. However, abnormal
eye movements and impaired cognition suggest a central nervous system disorder.
A single condition that includes all three of this patient’s signs and symptoms—eye
movement abnormalities, mental status change, and ataxia—is Wernicke’s ence-
phalopathy. Many other conditions can account for one or two of these signs and
symptoms, and these should be considered. Because Wernicke’s encephalopathy is
a result of vitamin B1 deficiency, further information from the patient regarding
nutrition is extremely important. Also, further details should be obtained regarding
the patient’s recent mental status.

Additional History

This patient had become depressed following recent surgery for head and neck cancer and
had limited her caloric intake severely. In the month before evaluation, her sole caloric
intake consisted of ethanol. During the past 2 weeks, the patient had become increasingly
forgetful and confused and was brought in for evaluation by her family when she became
disoriented.

344
 CASE 53: WERNICKE’S ENCEPHALOPATHY 345

Physical Examination

The patient was an emaciated woman with a supine blood pressure of 100/60. Neurologic
examination revealed that she was not oriented to person, place, or time. She was unable to
remember any objects at 1 minute during memory testing. Cranial nerve examination
revealed upbeating nystagmus in the primary position that was diminished with upgaze and
increased with downgaze, the reverse of that expected from Alexander’s law (see Case 1).
The patient could not move her eyes horizontally when asked to do so. There was facial
asymmetry and an inability to protrude the tongue, both presumably caused by the radial
neck dissection and hemiglossectomy. Coordination testing revealed a severe dysmetria of
the upper and lower extremities. The deep tendon reflexes were normal. Sensation could
not be assessed reliably. Romberg’s test could not be performed because the patient could
not stand with her eyes open without assistance. Her gait was severely ataxic. Otoscopic
examination was normal.
Question 2: What is the etiology and the pathophysiologic basis of upbeating nystagmus?
Answer 2: The etiology of upbeating nystagmus is highly varied and given in Case 53:
Table 1. Note that abnormalities in numerous locations in the nervous system can
be associated with upbeating nystagmus and that many disorders associated with
upbeating nystagmus have an uncertain or distributed localization.
The pathophysiology of upbeating nystagmus is uncertain. Several mechanisms
have been hypothesized including an imbalance in vertical vestibulo-ocular pathways,
abnormal gaze-holding, and asymmetric vertical pursuit signals.1
This patient’s upbeating nystagmus diminished with upgaze and increased with
downgaze. This reversal of Alexander’s law suggests that abnormal gaze-holding is
unlikely in this case.

Laboratory Testing

Videonystagmography: Ocular motor testing revealed upbeating nystagmus that was not
changed when the patient was placed in darkness. Caloric testing revealed bilaterally
reduced responses; there was a minimal response to ice water irrigations bilaterally.

Case 53: Table 1 Etiologies of Upbeating Nystagmus

Cerebellar degeneration and atrophy

Multiple sclerosis
Infarction of medulla, cerebellum, or superior cerebellar peduncle
Tumors of medulla, cerebellum, or midbrain
Wernicke’s encephalopathy
Brainstem encephalitis
Meningitis
Congenital visual abnormalities
Thalamic arteriovenous malformation
Organophosphate poisoning
Tobacco
Source: Adapted with permission from Leigh RJ, Zee DS: The Neurology of Eye
Movements, ed 3. Oxford University Press, New York, 1999, p. 420.1
346 VESTIBULAR DISORDERS

Rotational testing revealed reduced responses with markedly increased phase lead.
An MRI scan of the brain was normal. Cerebrospinal fluid evaluation for carcinomatous
meningitis was normal.

Diagnosis/Differential Diagnosis

Question 3: Based on the patient’s history, physical examination, and laboratory tests,
what is the likely diagnosis?
Answer 3: This patient is probably suffering from Wernicke’s encephalopathy.
Case 53: Table 2 lists the clinical features of this condition, which is a result of
hypovitaminosis B1. The characteristic clinical features of this condition include
eye movement abnormalities, mental status change, and gait ataxia. An addi-
tional commonly seen feature of this condition is vestibular paresis, either
unilaterally or bilaterally, as assessed by caloric testing.2 This patient had
each of these four features. Presumably, the patient’s head and neck surgery
and her depression contributed to her poor nutritional habits and vitamin B1
deficiency.
Question 4: In what clinical settings is Wernicke’s encephalopathy seen?
Answer 4: Case 53: Table 3 indicates the conditions that predispose to Wernicke’s
encephalopathy. Alcoholism is the most common of these conditions.
Question 5: This patient demonstrated markedly increased phase lead on rotational
testing. What is the basis of this abnormality?
Answer 5: This patient’s abnormal phase lead on rotational testing suggests an
abnormality in the so-called velocity storage system.3 Velocity storage refers to a

Case 53: Table 2 Clinical Features of Wernicke’s Encephalopathy

Alcoholism
Prolonged intravenous feeding
Intravenous hyperalimentation
Hyperemesis gravidarum
Anorexia nervosa
Prolonged fasting
Refeeding after starvation
Gastric plication

Case 53: Table 3 Conditions Associated with Wernicke’s

Encephalopathy

Ocular motor abnormalities such as nystagmus and gaze palsy

Ataxia
Global confusional state
Vestibular paresis
Hypotension
Hypothermia
 CASE 53: WERNICKE’S ENCEPHALOPATHY 347

central nervous system circuit that maintains vestibular information beyond the
cessation of activity of the eighth nerve afferents induced by vestibular stimulation.
Thus, following a brief acceleratory stimulus, eighth nerve afferent activity will
return to baseline in 5 to 7 seconds, whereas vestibular-induced eye movements
may persist for about three to four times longer, that is, 15 to 30 seconds. A
possible purpose of the velocity storage system is to improve the function of the
VOR, especially for slow head movements. The velocity storage system is
also critical for the generation of optokinetic nystagmus and thus probably
plays a role during exposure to prolonged moving visual stimuli such as during
walking.4
The central nervous system structures important for the velocity storage
mechanism include the vestibular nucleus and the cerebellar uvula and nodulus.5
Thus, abnormalities in these structures or their interconnections can impair velocity
storage. However, despite their central nervous system localization, abnormalities
of velocity storage are also seen with damage to the peripheral vestibular system.6
Abnormalities of the velocity storage system appear as increased phase lead
during sinusoidal rotation and as a shortened VOR time constant, that is, an
increased rate of decay of postrotatory nystagmus following abrupt changes in
head velocity. There are no clinical correlates that are specific for abnormalities of
the velocity storage system. Many different disorders can cause abnormalities in the
velocity storage mechanism. Abnormal VOR dynamics indicative of abnormal velocity
storage are a sensitive but nonspecific indicator of vestibular system damage.
Question 6: What is the basis of this patient’s caloric reduction and abnormal VOR
dynamics?
Answer 6: Wernicke’s encephalopathy leads to reduced vestibular sensitivity, pre-
sumably because of damage to the vestibular nuclei in the medulla.2
This patient was given a diagnosis of Wernicke’s encephalopathy.

Treatment/Management

This patient was treated with intravenous thiamine. Her nystagmus resolved, and she
became less confused but had a persistent memory deficit. The gait ataxia persisted, though
to a somewhat lesser degree. The patient’s vestibular sensitivity improved so that bithermal
responses were reduced but not absent. Her VOR dynamics remained abnormal, as
evidenced by an increased phase lead of eye movements induced by sinusoidal rotation.

Summary

A 54-year-old woman presented with forgetfulness and abnormal eye movements several
months following hemiglossectomy for head and neck cancer. The patient was found to
have poor memory, upbeating nystagmus, and gait ataxia. Laboratory testing revealed
bilaterally reduced vestibular responses. The brain scan was normal. The patient was given
the diagnosis of Wernicke’s encephalopathy. Treatment consisted of intravenous thiamine.
The patient improved somewhat but was left with a persistent deficit in memory and
balance.
348 VESTIBULAR DISORDERS

Teaching Points

1. Wernicke’s encephalopathy, which is caused by vitamin B1 deficiency, is

characterized by the combination of abnormal eye movements, mental status
change, and ataxia. The most common condition in which Wernicke’s
encephalopathy is seen is alcoholism.
2. Eye movement abnormalities in Wernicke’s encephalopathy include various types
of nystagmus and gaze palsies.
3. Vestibular paresis, either unilaterally or bilaterally, is common in Wernicke’s
encephalopathy, probably as a result of damage to the vestibular nuclei in the
medulla.
4. Abnormal vestibulo-ocular reflex dynamics, for example, increase phase lead on
rotational testing, suggests dysfunction of the so-called velocity storage system. The
velocity storage system maintains central nervous system activity after excitation in the
eighth nerve decays.

References
1. Leigh RJ, Zee DS: The Neurology of Eye Movements, ed 4. New York: Oxford University
Press, 2006.
2. Ghez C: Vestibular paresis: A clinical feature of Wernicke’s disease. J Neurol Neurosurg
Psychiatry 32:132–139, 1969.
3. Furman JM, Becker JT: Vestibular responses in Wernicke’s encephalopathy. Ann Neurol
26:669–674, 1989.
4. Cohen B, Matsuo V, Raphan T: Quantitative analysis of the velocity characteristics of
optokinetic nystagmus and optokinetic after-nystagmus. J Physiol 270:321–344, 1977.
5. Waespe W, Cohen B, Raphan T: Dynamic modification of the vestibulo-ocular reflex by the
nodulus and uvula. Science 288:199–202, 1985.
6. Zee D, Yee R, Robinson D: Optokinetic responses in labyrinthine-defective human beings.
Brain Res 113:423–428, 1976.
Case 54
Rotational Vertebral Artery
Syndrome

History

A 60-year-old man presented with episodic dizziness that was associated with vertigo and
occasional alteration in level of consciousness. The patient could not recall a specific date
of onset although symptoms seemed to have begun approximately 6 months prior to
evaluation, possibly while he was hunting using a bow and arrow. The patient noted that
he was especially likely to experience his symptoms when turning his head to the right.
The patient indicated that he had no positional symptoms in bed. There was some
change in hearing and some ear noise on the left. Medical history was significant for
hypertension and coronary artery disease with cardiac stenting 2 years earlier.
Question 1: What are the diagnostic considerations for this patient?
Answer 1: The differential diagnosis for this patient is somewhat limited because of
the combination of vertigo and alteration in level of consciousness. Alteration in
level of consciousness suggests a central nervous system abnormality. However,
some patients who experienced vertigo sense a reduction in their cognitive abilities
while vertiginous, which can be interpreted as a reduced level of consciousness.
A diagnosis of benign paroxysmal positional vertigo should be considered given the
positional sensitivity, though the patient does not have dizziness while in bed. The
complaint of changes in hearing and sensation of ear noise suggests the possibility
of endolymphatic hydrops, that is, Meniere’s disease. Another diagnosis, although
quite rare, that should be considered is the rotational vertebral artery syndrome.

Physical Examination

General examination was normal. Neurologic examination was normal. Otologic exam-
ination was normal. Neurotologic examination was normal including a Dix-Hallpike
maneuver with only 30° of head-on-torso rotation with an additional 15° of upper body
rotation. However, in an effort to reproduce the patient’s symptoms with head turning, the
patient was asked to turn his head to the right approximately 60°. With this maneuver, the
patient experienced vertigo and the sensation of ear noise on the left. He was noted to have
oblique nystagmus that was both down-beating and left-beating.

349
350 VESTIBULAR DISORDERS

Question 2: Based on the additional information from physical examination, what is this
patient’s likely diagnosis?
Answer 2: This patient’s most likely diagnosis is the rotational vertebral artery
syndrome. The rotational vertebral artery syndrome has been defined by Brandt
and Baloh1 as "a dominant vertebral artery providing the major vertebrobasilar
blood supply which is compressed by contralateral head rotation at the C1-2 level."
Typically, with the provocative motion, patients experience vertigo with an asso-
ciated nystagmus whose horizontal component beats toward the compressed
artery. In this patient, there may be a dominant left vertebral artery that is com-
pressed when the patient turns his head to the right.

Laboratory Testing

Videonystagmography indicated normal ocular motor function, normal caloric responses,

and normal rotational responses.
VEMPs were normal.
Audiometry was normal.
Magnetic resonance imaging was normal. Magnetic resonance angiography revealed a
dominant left vertebral artery.

Diagnosis/Differential Diagnosis

This patient was given a diagnosis of the rotational vertebral artery syndrome.
Question 3: What is the pathophysiology of the rotational vertebral artery syndrome?
Answer 3: The precise pathophysiology of the rotational vertebral artery syndrome is
uncertain although a vascular mechanism is certain.2 Controversy surrounds the
question of whether the labyrinth, the brainstem, or both experience ischemia with
a reduction in blood flow as a result of compression of a dominant vertebral artery
with contralateral head turns3 (see Case 54: Figure 1). Recall that the blood supply to

Case 54: Figure 1 Magnetic resonance (MR) and dynamic angiography findings in a patient
with the rotational vertebral artery syndrome. (A) MR angiography fails to visualize the right
vertebral artery (VA). (B) Dynamic angiography demonstrates a patent left VA during leftward
head rotation. (C) Dynamic angiography demonstrates occlusion of the left VA at the C1-2 level
during rightward head rotation (arrow).
Source: With permission from Choi KD et al: Rotational vertebral artery syndrome: Oculographic analysis
of nystagmus. Neurology, 65(8):1287–1290, 2005. 4
 CASE 54: ROTATIONAL VERTEBRAL ARTERY SYNDROME 351

the labyrinth originates from the anterior inferior cerebellar artery, normally the first
branch of the basilar artery. Moreover, the blood supply to the brainstem arises
from major arterial branches such as the posterior inferior cerebellar artery and the
anterior inferior cerebellar artery as well as perforating arteries arising from the
basilar artery. Current thinking, however, is that in the absence of clearly defined
brainstem symptoms, vertigo, nystagmus, and tinnitus are likely related to labyr-
inthine ischemia.4

Treatment

Question 4: What are the treatment options for the rotational vertebral artery syndrome?
Answer 4: Treatment options for the rotational vertebral artery syndrome depend
upon the site of occlusion of the dominant vertebral artery. Dynamic angiography is
generally required to determine the site of occlusion.2 Exploration with fascial
decompression may be curative. Alternatively, discectomy and osteophyte removal
or unroofing of a foramen may be necessary. A vertebral fusion may be required.2
Stenting is another therapeutic option.5 Additionally, the patient should be advised
that end-range head turns, chiropractic manipulation of the neck, and whiplash
injuries may lead to infarction.

Follow-Up

The patient was referred for a neurosurgical evaluation and underwent dynamic angiogra-
phy and surgical decompression. The patient had an excellent postoperative result and was
asymptomatic. The patient, however, avoided extreme head rotations and gave up bow
hunting.

Summary

A 60-year-old man presented with episodic vertigo occasionally associated with an altera-
tion in level of consciousness. Symptoms began while hunting using a bow and arrow.
Medical history was significant for hypertension and coronary artery disease. On physical
examination, there was vertigo, a sensation of left ear noise on the left, and oblique
nystagmus when he turned his head to the right approximately 60°. Magnetic resonance
angiography revealed a dominant left vertebral artery. The patient was given a diagnosis of
the rotational vertebral artery syndrome. The patient underwent angiography, which
revealed compression of the left vertebral artery with right head turns. Following a surgical
decompression, the patient had an excellent result and was asymptomatic.

Teaching Points

Consider a diagnosis of the rotational vertebral artery syndrome in patients who

experience vertigo when turning the head far to the right or left.

1. The rotational vertebral artery syndrome is rare.

352 VESTIBULAR DISORDERS

2. Before making a diagnosis of the rotational vertebral artery syndrome, more

common conditions should be ruled out.
3. Establishing a definitive diagnosis of the rotational vertebral artery syndrome
requires dynamic angiography.
4. The pathophysiology of the rotational vertebral artery syndrome relates to
ischemia of either the labyrinth, the brainstem, or both.
5. Treatment for the rotational vertebral artery syndrome may include surgical
decompression.
6. Patients with the rotational vertebral artery syndrome should be advised that
extreme head turns, chiropractic manipulation of the neck, and whiplash
injuries may lead to infarction.

References

1. Brandt T, Baloh RW: Rotational vertebral artery occlusion: A clinical entity or various
syndromes? Neurology 65(8):1287–1290, 2005.
2. Kuether TA, Nesbit GM, Clark WM, Barnwell SL: Rotational vertebral artery occlusion: A
mechanism of vertebrobasilar insufficiency. Neurosurgery Online 41(2):427–433, 1997.
3. Way M, Parton RG: M-caveolin, a muscle-specific caveolin-related protein. FEBS Lett
376:108–112, 1995.
4. Choi KD, Shin HY, Kim JS, KimSH, Kwon OK, Koo JW, Park SH, Yoon BW, Roh JK:
Rotational vertebral artery syndrome: Oculographic analysis of nystagmus. Neurology
65(8):1287–1290, 2005.
5. Kerber KA, Rasmussen PA, Masaryk TJ, Baloh RW: Recurrent vertigo attacks cured by
stenting a basilar artery stenosis. Neurology 65(2 of 2):962, 2005.
Case 55
Sleep Disorders and
Vestibulopathy

History

A 41-year-old man presented with an 18-month history of dizziness. The patient’s dizzi-
ness was characterized as an episodic brief sense of presyncope and lightheadedness
associated with occasional imbalance and some veering of gait. Dizziness was exacerbated
by vertical gaze changes and by driving. At the onset of symptoms the patient was
diagnosed with and treated for hypertension without any benefit regarding his dizziness.
Symptoms were worse with exertion and stress. There were occasional mild headaches,
some difficulty with short-term memory, mild difficulty with concentration and word
finding, mild episodic neck pain, and mild space and motion discomfort. The patient’s
history was significant for generalized anxiety without panic attacks currently untreated in
addition to his hypertension. The patient had tried meclizine without benefit for his
dizziness.
Question 1: Based on the patient’s history, what diagnostic entities should be considered?
Answer 1: This patient’s history does not suggest a specific diagnosis. Moreover, the
nonspecific nature of the patient’s complaints leads to a very broad differential
diagnosis, which could include a vestibular system abnormality. The failure of
meclizine to provide relief suggests that a vestibulopathy is less likely.

Additional History

The patient’s sleeping partner related that the patient suffered from sleep apnea with
stertorous breathing during the night and periods of apnea, hyperventilation, and arousal.
The patient had refused to undergo a sleep evaluation despite urging by his family and
primary care physician.
Question 2: Based upon the patient’s additional history what other diagnostic considera-
tion should be considered?
Answer 2: The patient’s history suggests sleep apnea, which may be contributing to
his symptoms of dizziness by exacerbating the symptoms caused by a vestibular
disorder or by causing symptoms de novo.

353
354 VESTIBULAR DISORDERS

Physical Examination

The patient’s physical examination was entirely normal including his general examination,
neurologic examination, otologic examination, and neurotologic examination. The
patient’s blood pressure was normal without postural changes.

Laboratory Testing

Videonystagmography revealed normal ocular motor function, no positional nystagmus,

normal caloric responses, a borderline directional preponderance on rotational testing, and
normal vestibular evoked myogenic potentials.
Computerized dynamic posturography indicated a vestibular pattern.
Audiometric testing was normal bilaterally.
Question 3: Based on the patient’s history, physical examination, and laboratory testing,
what are the diagnostic considerations?
Answer 3: The patient appears to be suffering from a mild vestibulocular system
imbalance and increased postural sway consistent with a vestibular abnormality. It
is likely that the patient’s sleep disorder is contributing to his presentation.1,2,3

Diagnosis/Differential Diagnosis

The patient was given a diagnosis of a mild vestibulopathy in combination with sleep
apnea.
Question 4: In what way can a sleep disorder influence the manifestations of a vestibular
abnormality?
Answer 4: Sleep deprivation can lead to increased postural sway.4 The effect of sleep
deprivation on the vestibulo-ocular reflex is inconsistent.5,6 A sleep disorder may
exacerbate the symptoms of a mild peripheral vestibular imbalance by interfering
with vestibular compensation. Moreover, sleep abnormalities such as sleep apnea
can lead to excessive daytime somnolence and dizziness independent of a vestib-
ular system abnormality. Some of the patient’s complaints such as difficulty with
short-term memory, mild headaches, poor concentration, and word finding could
be attributed to his sleep disorder.7

Treatment

Question 5: What treatments should be considered for this patient?

Answer 5: This patient should be encouraged to undergo a sleep evaluation.
A treatment option is vestibular rehabilitation therapy and symptomatic treatment
with a low dose of a benzodiazepine. However, these treatment modalities would
depend upon the patient’s sleep evaluation, sleep disorder diagnosis, and sleep
disorder treatment.
 CASE 55: SLEEP DISORDERS AND VESTIBULOPATHY 355

Follow-Up

The patient underwent a sleep evaluation and was diagnosed with obstructive sleep apnea.
The patient was advised to decrease his weight and use continuous positive airway pressure
(CPAP) at night. At the patient’s follow-up visit his dizziness symptoms were diminished
but remained present especially with vertical gaze changes. The patient underwent vestib-
ular rehabilitation therapy with a further reduction in symptoms.

Summary

A 41-year-old man presented with an 18-month history of episodic nonspecific dizziness,

presyncope, lightheadedness, mild headache, imbalance, and some veering of gait.
Information provided by his wife suggested that the patient suffered from sleep apnea.
Laboratory testing indicated a mild vestibular system imbalance. The patient was given a
diagnosis of a mild vestibulopathy in combination with sleep apnea. A sleep evaluation led
to his use of continuous positive airway pressure (CPAP) at night. Dizziness symptoms
were diminished.

Teaching Points

1. The manifestations of a vestibulopathy can be exacerbated by the presence of a

sleep disorder.
2. The mechanism whereby a sleep disorder exacerbates a vestibulopathy is
uncertain but may relate to interference with central compensatory mechanisms.
3. Patients with vestibular system abnormalities should be questioned regarding
their sleep behavior. Appropriate referrals should be made. Note that for some
patients, information regarding sleep behavior may be best obtained from the
patient’s sleeping partner.

References
1. Patel M, Gomez S, Berg S, Almbladh P, Lindblad J, Petersen H, Magnusson M, Johansson R,
Fransson PA: Effects of 24-h and 36-h sleep deprivation on human postural control and
adaptation. Exp Brain Res 185:165–173, 2008.
2. Karita K, Nakao M, Nishikitani M, Iwata T, Murata K, Yano E: Effect of overtime work and
insufficient sleep on postural sway in information-technology workers. J Occup Health
48:65–68, 2006.
3. Schlesinger A, Redfern MS, Dahl RE, Jennings JR: Postural control, attention and sleep
deprivation. Neuroreport 9:49–52, 1998.
4. Morad Y, Azaria B, Avni I, Barkana Y, Zadok D, Lohen-Raz R, Barenboim E: Posturography
as an indicator of fatigue due to sleep deprivation. Aviat Space Environ Med 78(9):859–863,
2007.
5. Collins WE: Some effects of sleep toss on vestibular responses. Aviat Space Environ Med
59(6):523–529, 1988.
6. Quarck G, Ventre J, Etard O, Denise P: Total sleep deprivation can increase vestibulo-ocular
responses. J of Sleep Res 15(4):369–375, 2006.
7. Kim HC, Young T, Matthews GC, Weber SM, Woodward AR, Palta M: Sleep-disordered
breathing and neuropsychological deficits. A population-based study. Am J Respir Crit Care
Med 156(6):1813–1819, 1997.
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Part VI

Clinical Controversy Case Studies

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Case 56
Malingering

What is controversial about malingering? Whether a patient is willfully attempting to

deceive the physician, is manifesting a conversion disorder, or has a highly unusual
nonphysiologic presentation is often uncertain. Determining the patient’s status is often
important both medically and legally.

History

A 34-year-old male construction worker complained of dizziness for 3 months. The patient
dated the onset of symptoms to a head injury that occurred on the job. While he was
wearing his hardhat, a small piece of construction equipment weighing about 2 pounds fell
several feet and struck him on top of the head. The patient had no loss of consciousness and
was able to continue working that day. The next day, he did not report for work and
presented to a local emergency room complaining of dizziness. His evaluation, including a
CT scan of the head, disclosed no apparent abnormality, and he was released. The patient
returned to work the next day but could not tolerate the increased dizziness that his work
provoked. He has not worked since that time. His primary care physician prescribed a
nonsteroidal anti-inflammatory agent, but the patient remained symptomatic. The patient’s
dizziness was characterized by a constant sense of lightheadedness that was exacerbated by
exertion. He did not complain of visual motion sensitivity, worsening of symptoms with
rapid head movement, or gait instability. His medical history was negative, except for a
concussion with loss of consciousness for several minutes 10 years earlier that was
sustained in a motor vehicle accident. The patient was using no medications, smoked
one pack of cigarettes per day, and consumed alcohol occasionally without worsening of
his dizziness.

Question 1: What diagnostic entities should be considered?

Answer 1: The patient’s symptoms are nonspecific and are not highly suggestive of a
vestibular abnormality. The head trauma was mild and probably was not associated
with a labyrinthine concussion, but this must be considered. A postconcussion
syndrome also should be considered, although the patient did not lose conscious-
ness and did not complain of headache.

359
360 VESTIBULAR DISORDERS

Physical Examination

The neurologic examination was normal, except that the patient demonstrated excessive
sway during Romberg testing without falling. Otologic examination was normal.
Neurotologic examination revealed no spontaneous nystagmus, a normal head thrust,
negative Dix-Hallpike testing, and excessive sway without falling while standing on a
foam pad both with eyes open and with eyes closed.
Question 2: What is malingering? Which audiovestibular measures can be used to help
assess for malingering?
Answer 2: Malingering has been defined as ‘‘the false and fraudulent simulation or
exaggeration of physical or mental disease or defect, performed in order to obtain
money or drugs, to evade duty or criminal responsibility, or for other reasons that
may be readily understood by an objective observer from the individual’s circum-
stances, rather than from learning the individual’s psychology.’’1
Some audiovestibular tests are objective and require minimal patient coopera-
tion, such as an assessment of nystagmus during ocular motor screening, positional
testing, caloric testing, and rotational testing. Posturography requires much coop-
eration and can yield results that suggest malingering or lack of cooperation on the
part of the patient. Several studies have asked persons to feign, that is, simulate,
posturographic abnormalities.2–4 These persons produced posturography patterns
that looked aphysiologic.5 However, an aphysiologic pattern on posturography
does not necessarily indicate malingering, since aphysiologic patterns have been
found both in patients with psychiatric disorders and in suspected malingerers.5
Audiologists are trained to detect inconsistent responses during hearing tests
that suggest possible factitious hearing loss. Several special audiometric tests, such
as Stenger’s test, can be used to uncover factitious hearing. Two particular abnorm-
alities of posture and gait, astasia-abasia, which is characterized by instability at the
hip, and camptocormia, which is characterized by forward leaning at the hip, have
been linked to psychiatric disorders but these postural patterns may be maladaptive
behaviors in response to physiologic abnormalities.7,8 A study by Gianoli et al.9
determined that patients with the potential for secondary gain had a lower percen-
tage of abnormalities on electronystagmography and an aphysiologic sway pattern
on posturography. A study by Mallinson and Longridge provides a clinical scheme
for uncovering malingering.9,10

Laboratory Testing

Videonystagmography: Ocular motor, postural, and caloric tests were normal. Rotational
testing was normal. Vestibular-evoked myogenic potentials were normal. Posturography
revealed excessive sway during sensory conditions 1, 2, and 3 but not 4, 5, and 6, that is, an
aphysiologic pattern.
Audiometric testing revealed a bilateral high-frequency sensorineural hearing loss
consistent with noise-induced hearing loss.
MRI scan of the brain was normal.
Question 3: Based on the additional information from the physical examination and
laboratory tests, what is the differential diagnosis? Is this patient malingering?
 CASE 56: MALINGERING 361

Answer 3: No definite diagnosis can be made based on the additional information

from the physical examination and laboratory tests. The abnormal posturography
showed an aphysiologic pattern. Given the patient’s unwillingness or inability
to return to work, malingering must be suspected but cannot be confirmed. The
patient had no abnormalities of posture and gait aside from excessive sway
on Romberg testing and no evidence of a factitious hearing loss. His laboratory
tests were normal, aside from posturography, which further supports possible
malingering.

Diagnosis/Differential Diagnosis

This patient was given a diagnosis of dizziness of uncertain etiology. Malingering was
considered possible but could not be confirmed.

Treatment

Question 4: What treatment, if any, would be appropriate for this patient?

Answer 4: It is difficult to recommend treatment for patients with poorly defined
symptoms who may be malingering. The patient was sent to a physical therapist for a
functional balance assessment (see Chapter 6) and a course of vestibular rehabilitation.

Follow-Up

The patient was retested on posturography as part of the physical therapy assessment 1
week later. Again the results were unusual. The patient had excessive sway on conditions 1
and 2 but had normal sway patterns on conditions 3 to 6, indicating inconsistencies with the
first posturography test that also demonstrated an aphysiologic pattern. The patient con-
tinued to have difficulty standing on the foam pad with eyes open and closed. The Dynamic
Gait Index score was 23 out of 24, the Dizziness Handicap Inventory score was 84, and the
Activities-specific Balance Confidence score was 65% (see Chapter 6). The patient’s
perceived dizziness on a 0–100 scale was 90, and he stated that his dizziness was constant.
The patient was given a home exercise program to address his balance dysfunction during
standing. He was seen on follow-up on two occasions for vestibular rehabilitation. The
patient’s scores on both objective and subjective functional balance assessment measures
remained unchanged, and vestibular rehabilitation was discontinued.
The patient subsequently filed a disability claim that was denied. The patient planned to
enlist the aid of an attorney and to appeal the negative decision.

Summary

A 34-year-old construction worker complained of dizziness following minor head trauma

without loss of consciousness. During assessment, he evidenced excessive sway during
Romberg testing and an aphysiologic pattern during posturography, suggesting the possi-
bility of malingering. No definitive diagnosis could be reached. The patient did not return
to work and filed a disability claim.
362 VESTIBULAR DISORDERS

Teaching Points

1. Malingering has been defined as ‘‘the false and fraudulent simulation or

exaggeration of physical or mental disease or defect, performed in order to
obtain money or drugs, to evade duty or criminal responsibility, or for other
reasons that may be readily understood by an objective observer from the
individual’s circumstances, rather than from learning the individual’s
psychology.’’1
2. Some audiovestibular tests are objective and require minimal patient cooperation,
whereas posturography requires much cooperation.
3. Posturography can yield results that suggest malingering or a lack of cooperation
on the part of the patient.
4. An aphysiologic pattern on posturography does not necessarily indicate
malingering since aphysiologic patterns have been found in patients with
psychiatric disorders and suspected malingering.
5. Audiometric testing using one of several tests, such as Stenger’s test, can uncover a
factitious hearing loss.

References
1. Gorman WF: Defining malingering. J Forensic Sci 27(2):401–407, 1982.
2. Uimonen S, Laitakari K, Kiukaanniemi H, Sorri M: Does posturography differentiate mal-
ingerers from vertiginous patients? J Vestib Res 5(2):117–124, 1995.
3. Goebel JA, Sataloff RT, Hanson JM, Nashner LM, Hirshout DS, Sokolow CC: Posturographic
evidence of nonorganic sway patterns in normal subjects, patients, and suspected malingers.
Otolaryngol Head Neck Surg 117:293–302, 1997.
4. Krempl GA, Dobie RA: Evaluation of posturography in the detection of malingering subjects.
Am J Otol 19:619–627, 1998.
5. Cevette MJ, Puetz B, Marion MS, Wertz ML, Muenter MD: Aphysiologic performance on
dynamic posturography. Otolaryngol Head Neck Surg 112:676–688, 1995.
6. Sinel M, Eisenberg MS: Two unusual gait disturbances: Astasia abasia and camptocormia.
Arch Phys Med Rehabil 71:1078–1080, 1990.
7. Kumral E, Locaer T, Sagduyu A, Sirin H, Toygar A, Evyapan A, Vuilleumier P. Callosal
infarction after bilateral occlusion of the internal arteries with hemineglect syndrome and
astasia-abasia. Revue Neurologique 151(3) 202–205, 1995.
8. Azher SN, Jankovic J: Camptocormia: Pathogenesis, classification, and response to therapy.
Neurology 65(1 of 2):355–359, 2005.
9. Gianoli G, McWilliams S, Solileau J, Belafsky P: Posturographic performance in patients with
the potential for secondary gain. Otolaryngol Head Neck Surg 122:11–18, 2000.
10. Mallinson AI, Longridge NS: A new set of criteria for evaluating malingering in work-related
vestibular injury. Otol Neurotol 26:686–690, 2005.
Case 57
Driving and Dizziness

History

What is controversial about driving and dizziness? There is controversy regarding which
patients should be permitted to continue driving. Should permission depend upon the
diagnosis? Is the type of vehicle important?
A 46-year-old female school bus driver was evaluated for dizziness that occurred inter-
mittently during the preceding 18 months. Symptoms occurred as often as several times
each day or as infrequently as several times per week. Dizziness consisted of episodes
lasting for a few seconds to several minutes. These episodes were characterized by a slight
visual change causing double and blurred vision. The patient also had episodic numbness.
She noted a sense of lightheadedness, a sensation of movement, and gait instability with the
episodes. There was also occasional associated nausea and head pressure and circumoral
paresthesias. The patient did not complain of blindness, weakness, clumsiness, confusion,
or loss of consciousness. Her medical history was significant for myocardial infarction 8
years earlier, hypertension, and a remote history of migraine headaches, although none for
approximately 20 years. Current medications included an anti-hypertensive agent and a
cholesterol-lowering agent. The patient smoked one pack of cigarettes per day and did not
use alcohol.
Question 1: Based on the patient’s history, what is the diagnosis?
Answer 1: This patient’s history does not suggest a definitive diagnosis. Rather,
it suggests a nonspecific disorder that may be vestibular or nonvestibular in
origin. The patient’s history of migraine headaches suggests the possibility of
migraine-related vestibulopathy, but the patient has been headache free for 20
years.

Physical Examination

Neurologic and otologic examinations were normal. Neurotologic examination also was
normal, including a search for spontaneous nystagmus, a normal head thrust, a negative
Dix-Hallpike test, and normal stability on a foam pad.

363
364 VESTIBULAR DISORDERS

Laboratory Testing

Videonystagmography: Ocular motor, positional, and caloric tests were normal. Rotational
testing revealed a moderately reduced magnitude of responses without asymmetry.
Posturography testing and audiometry were normal. MRI scan of the brain was normal,
as were noninvasive carotid studies.
Question 2: Based on the history, physical examination, and laboratory tests, what are the
diagnostic possibilities for this patient?
Answer 2: The additional information provided by the physical examination and
laboratory tests still does not provide an obvious diagnosis. The patient’s presenta-
tion remains consistent with nonspecific dizziness of uncertain etiology, possibly
related to a vestibular disorder.

Diagnosis/Differential Diagnosis

This patient was given a diagnosis of nonspecific vestibulopathy.

Treatment

Question 3: What are the treatment options for this patient?

Answer 3: Treatment options include further investigation of her dietary habits with
counseling to encourage adoption of a low-salt diet and education regarding diet-
ary migraine triggers, reduction and avoidance of nicotine and overuse of caffeine,
use of a low-dose vestibular-suppressant on an as-needed basis, and medical
treatment for migraine-related vestibulopathy, for example, with a tricyclic anti-
depressant.
The patient underwent dietary counseling and was prescribed imipramine, 10
mg orally at hour of sleep.
Question 4: Under what circumstances might a patient with a vestibular disorder have
difficulty operating a motor vehicle and why?
Answer 4: A patient with a vestibular abnormality might be expected to have
difficulty operating a motor vehicle because of the combination of active and
passive head and eye movements used while driving.1 Thus, a patient with a
vestibular disorder may have increased difficulty driving on very curved roads and
exit ramps, even at posted speeds, and while driving in ramped or circular parking
garages. A patient with a vestibular disorder also may be challenged by the visual–
vestibular interaction associated with driving. When one looks at objects outside of
the vehicle, the visual and vestibular systems act in concert, whereas when one
looks at objects inside the vehicle, such as the speedometer, the VOR must be
suppressed or canceled. Many patients with a vestibular disorder are bothered by
visual motion. This problem may be particularly evident while driving across
bridges and through tunnels. A patient with a vestibular disorder would be
expected to have more difficulty when driving at night, at high speed, and under
adverse weather conditions.
 CASE 57: DRIVING AND DIZZINESS 365

Some types of vestibular stimulation cause sleepiness, the so-called sopite syn-
drome.2 Patients with vestibular disorders may be prone to the sopite syndrome
while driving.
Question 5: Does dizziness frequently interfere with driving?
Answer 5: According to a recent survey, about one-half of vestibular patients felt
dizzy when driving, but 84% believed that they could pull over to the side of the
road safely if they felt dizzy.3 Also, 12% stated that they had been injured because of
dizziness while driving.3
Question 6: Are there any particular vestibular disorders that are especially worrisome in
patients driving a motor vehicle?
Answer 6: Certain vestibular disorders are more worrisome than others in patients
driving a motor vehicle. The 1997 American Neurotologic Society consensus
recommendations state that patients with Tumarkin’s otolithic crisis (see Case 40)
should be advised to stop driving until the episodes are treated or cease.3 Patients
with chronic vestibular symptoms are more likely than patients with episodic
dizziness to express difficulty driving and to admit that their dizziness interfered
with driving. Thus, patients with chronic dizziness who express concern over driv-
ing should be advised to have a road test.4 Patients with bilateral vestibular loss
especially associated with oscillopsia should be cautioned to avoid driving. Also,
patients who are using medications to control dizziness that may impair alertness or
that slow their reaction time should be cautioned about the possible effects of the
medications on driving.
Question 7: What options are available for the assessment of a dizzy patient’s ability to
operate a motor vehicle?
Answer 7: A certified driving rehabilitation specialist can evaluate patients with chronic
dizziness during a road test. Such facilities are not commonly available but do exist.
Question 8: What are the legal requirements regarding the reporting of patients with
dizziness, disequilibrium, and vestibular disorders to government agencies such as the
Department of Transportation?
Answer 8: In Pennsylvania, physicians are required to report individuals who suffer
loss of consciousness or ‘‘Any other condition which, in the opinion of the provider,
is likely to impair the ability to control and safely operate a motor vehicle.’’5 This
does not include persons with dizziness, disequilibrium, or vestibular disorders.
Reporting guidelines in other states and other countries may differ.
Question 9: This patient’s history indicated that she drove a school bus. Should the patient
be advised not to drive a school bus? What about a passenger vehicle?
Answer 9: The appropriate instructions regarding driving for a patient with dizziness
are controversial. There are no data regarding driving ability in patients with
vestibular disorders to help answer this question. The three most common con-
tributing factors for motor vehicle accidents are alcohol intoxication, driver inex-
perience, and falling asleep. Dizziness is not among them. The uncertainty
regarding driving and dizziness is exemplified by the following advice issued by
the Driver and Vehicle Licensing Agencies (DVLA) of the United Kingdom, which
suggests that ‘‘Vertigo is a common condition and would rarely be severe enough
to make driving unsafe. Whether a patient should be advised to stop driving will
depend on the doctor’s judgment of the severity and frequency of the attacks and it
366 VESTIBULAR DISORDERS

is difficult to lay down rigid criteria.’’6 The DVLA of the United Kingdom also notes
that drivers of passenger vehicles ‘‘liable to sudden attacks of disabling giddiness
and fainting such as Meniere’s disease, labyrinthine or other brainstem disorders
should cease driving on diagnosis.’’ For drivers of commercial vehicles, the DVLA
recommends ‘‘refusal or revocation of a commercial driver’s license if the condition
is disabling. If the condition is stable, the driver must be symptom free and com-
pletely controlled for at least one year before reapplication.’’
Question 10: Do patients with dizziness alter their driving habits? Do patients generally
comply with the advice of their physicians regarding driving?
Answer 10: Patients with dizziness do alter their driving habits. In particular, patients
with chronic imbalance reduce their amount of driving.7 In general, patients do not
comply with their physician’s recommendations regarding driving. In particular,
56% of dizzy patients said they would continue to drive even if their doctor warned
them that it would be dangerous to do so. Hence, if the physician is truly concerned
about the driving fitness of a patient, a prudent approach may be to report the
patient to the appropriate authorities.

Follow-Up

Based on the patient’s symptoms and her discussion with her physician, she voluntarily
took a leave of absence from her job as a school bus driver.

Summary

A 46-year-old school bus driver was evaluated for dizziness. No definitive diagnosis could
be reached, and the patient was treated presumptively for migraine-related dizziness with
low-dose imipramine. She voluntarily took a leave of absence from her job because of her
concern about driving safety.

Teaching Points

1. When eliciting the history of a patient with dizziness, it is appropriate to obtain a

driving history.
2. Patients with vestibular abnormalities might be expected to have difficulty
operating a motor vehicle. Because of the combination of active and passive head
movements encountered while driving and the requirement for visual–vestibular
interaction, patients with vestibular disorders may have increased difficulty operating
motor vehicles even while driving under ideal conditions.
3. Certain vestibular disorders are more worrisome than others for patients driving a
motor vehicle, such as Tumarkin’s otolithic crisis and chronic constant dizziness.
4. In Pennsylvania, physicians are not required to report individuals with dizziness,
disequilibrium, or vestibular disorders. Reporting guidelines in countries other than
the United States may differ.
5. The appropriate instructions regarding driving for a patient with dizziness are
controversial but should probably be different for driving commercial vehicles
compared to passenger vehicles.
 CASE 57: DRIVING AND DIZZINESS 367

6. Patients with chronic dizziness should reduce their amount of driving. However,
most patients continue to drive even if their doctor warns them that it would be
dangerous to do so.

References

1. Cohen HS, Wells J, Kimball KT, Owsley C: Driving disability and dizziness. J Safety Res
34(4):361–369, 2003.
2. Lawson BD, Mead AM: The sopite syndrome revisited: Drowsiness and mood changes during
real or apparent motion. Acta Astronautica 43(3–6):181–192, 1998.
3. Sindwani R, Parnes LS, Goebel JA, Cass SP: Approach to the vestibular patient and driving.
A patient perspective. Otolaryngol Head Neck Surg 121:13–17, 1999.
4. Moser M: An objective testing method to determine driving ability. Acta Otolaryngol
(Stockh) 99:326–329, 1985.
5. Annex A. Title 67: Transportation, Part I. Department of Transportation, Subpart A. Vehicle
Code Provisions, Article IV. Licensing, Chapter 83, Physical and Mental Criteria Including
Vision Standards Relating to the Licensing of Drivers, Motor Vehicle Operations. Harrisburg:
Pennsylvania Department of Transportation, p 7.
6. Mckiernan D, Jonathan D: Driving and vertigo. Clin Otolaryngol Allied Sci 26(1):1–3, 2001.
7. Hoffman HJ, Ko C, Sklare DA: How is the frequency of driving an automobile affected by
chronic (31 months) problems with imbalance and/or dizziness? Presented at the American
Public health Association National Meeting, October 2001.
Case 58
Cervicogenic Dizziness

What is controversial about cervicogenic dizziness? There is controversy regarding the

very existence of cervicogenic dizziness, or cervical vertigo.1 Thus, questions abound
regarding how such a diagnosis can be established and how such patients should be treated.

History

A 49-year-old male delivery van driver presented with the chief complaint of dizziness and
lightheadedness during the previous 5 months. The patient had symptoms that fluctuated
daily. Head movements exacerbated his symptoms, as did being in large rooms or complex
visual environments. The patient had no complaints of hearing loss or tinnitus and no
neurologic complaints. He dated the onset of symptoms to an automobile accident in which
he was struck from the rear, causing him to experience a flexion-extension ‘‘whiplash’’ injury
of the neck. The patient did not strike his head or lose consciousness during the accident. His
symptoms were worse on the days when he experienced neck pain or neck muscle spasm.
There was no significant medical history. The family history was noncontributory.
Question 1: Based on the patient’s history, what is the likely diagnosis?
Answer 1: Exacerbation of the patient’s symptoms with head movement suggests a
balance abnormality, possibly vestibular in origin. The patient also appears to be
suffering from space and motion discomfort. The close association of his symptoms
with neck pain and their onset following a neck injury suggests that this patient’s
complaints are likely to be a result of cervicogenic dizziness, also known as cervical
vertigo.2,3 Cervicogenic dizziness is a controversial diagnosis that is often considered
when patients have dizziness and disequilibrium in association with neck pain. Other
diagnostic considerations include benign paroxysmal positional vertigo, post-
traumatic endolymphatic hydrops, peripheral vestibulopathy of uncertain etiology,
or a central nervous system abnormality, structural or otherwise, that is now manifest-
ing as dizziness either independent of or exacerbated by the motor vehicle accident.

Physical Examination

General, neurologic, and otologic examinations were normal, with the exception of
decreased range of motion of the neck and a complaint of disequilibrium when turning
the head, especially when attempting to bring the chin to the shoulder in either direction.

368
 CASE 58: CERVICOGENIC DIZZINESS 369

Case 58: Figure 1 Head-fixed, body-turned maneuvers. With the patient on a swivel chair, the
examiner stabilizes the head while the patient turns the body in such a way that the torso rotates
with respect to the head, thereby stimulating the neck without stimulating the labyrinth.
Source: With permission from Fitz-Ritson D: Assessment of cervicogenic vertigo. J Manipulative Physiol
Ther 14(3):193–198, 1991, p 195. 12

Head-fixed, body-turned maneuvers (Case 58: Figure 1) were performed with infrared
goggles with the head held still and the body turned while the patient sat on a swivel chair.
He experienced dizziness and was noted to have several beats of right-beating nystagmus
during rotation of the body to the left while he was looking straight ahead.
Question 2: Based on the history and physical examination, what is this patient’s likely
diagnosis? What laboratory tests would be helpful in establishing a diagnosis?
Answer 2: This patient’s history and physical examination are suggestive of cervico-
genic dizziness with an abnormal cervico-ocular reflex. Given the uncertainty of this
diagnosis and the controversial nature of cervicogenic dizziness, both brain ima-
ging and quantitative vestibular testing are warranted.

Laboratory Testing

Videonystagmography: Ocular motor function was normal.

An MRI scan of the brain was normal.
Right-beating nystagmus during head-fixed, body-turned maneuvers was recorded with
the body turned to the left. This was seen in both the lying and seated positions.
370 VESTIBULAR DISORDERS

Question 3: What is the cervico-ocular reflex? What is a possible explanation for this
patient’s disequilibrium?
Answer 3: The cervico-ocular reflex is an eye movement response to relative move-
ment of the head with respect to the torso, that is, neck movement. The reflex is
based upon afferent activity from the neck rather than from the labyrinth. Relative
movement between the head and the torso alters the neural activity relayed to the
vestibular nuclei regarding head position. These afferents primarily comprise neck
muscle proprioceptive fibers.4 This innervation may arise from joint afferents in the
neck.4 Also, other nerves may arise from facet joints in the cervical spine. The
cervico-ocular reflex is thought to be of minimal importance in normal individuals,
because quantitative testing of the reflex has revealed minimal eye movements as a
result of relative motion between the head and torso with the head fixed in space.5-7
However, numerous case reports attest to the dizziness and disequilibrium experi-
enced by patients who have sustained neck injuries, and some patients have
demonstrated nystagmus during the head-fixed, body-turned maneuver.8 Also,
anesthetizing one side of the neck produces acute disequilibrium and imbalance.9
Vibration of the neck in patients with a unilateral vestibular lesion also suggests an
increase in signals from the neck.10 This patient appears to have a heightened
cervico-ocular reflex when the body is turned to the left, so that clearly visible
nystagmus was generated.
Question 4: What is the significance of this patient’s episodic neck muscle spasm and its
association with symptoms of dizziness?
Answer 4: The cause-and-effect relationship between the patient’s neck muscle
spasm and his symptoms of dizziness is uncertain. As described above, abnormal
afferent activity from the neck could lead to dizziness as a result of the central
nervous system receiving aberrant information regarding the position of the head in
space. Such aberrant information could be made more unreliable by neck muscle
spasm. Conversely, the vestibulo-colic and cervico-colic reflexes (see Chapter 1),
which are designed to help stabilize the head in space, could be leading to excessive
neck muscle activity when the patient is experiencing a vestibular imbalance. Thus,
patients with cervicogenic dizziness may experience a ‘‘vicious cycle’’ of excessive
neck muscle activity exacerbating their dizziness, which subsequently exacerbates
their neck discomfort.
Question 5: What types of injuries can cause cervicogenic dizziness?
Answer 5: Cervicogenic dizziness has been reported in flexion-extension injuries
often related to motor vehicle accidents, severe cervical arthritis, herniated cervical
disks, and trauma, especially blunt trauma to the top of the head.11

Diagnosis/Differential Diagnosis

This patient was given the diagnosis of cervicogenic dizziness.

Treatment/Management

Cyclobenzaprine was prescribed as a muscle relaxant to be used on an as-needed basis. A

soft cervical collar was also prescribed for the patient, and he was admonished not to use
 CASE 58: CERVICOGENIC DIZZINESS 371

the collar for more than 1 to 2 hours per day so that he did not lose neck muscle strength and
continued to stimulate neck proprioception. This patient was treated with physical therapy
to improve range of motion of the neck13 and to reduce neck muscle spasm and discomfort.
These treatment interventions provided significant relief, but he remained symptomatic,
especially if he was required to turn his head repeatedly for several hours—for instance,
while driving an automobile for long distances.

Summary

A 49-year-old man presented with the chief complaint of dizziness whose onset was
associated with a flexion-extension injury during a motor vehicle accident. Examination
revealed nystagmus during head-fixed, body-turned maneuvers, suggesting the diagnosis
of cervicogenic dizziness. The patient was treated with physical therapy, muscle relaxants,
and a soft cervical collar and gained symptomatic relief.

Teaching Points

1. Cervicogenic dizziness is a controversial diagnosis that refers to dizziness and

disequilibrium thought to be caused by abnormal afferent activity from the neck.
The close temporal association of symptoms of dizziness and neck pain following a
neck injury should suggest a diagnosis of cervicogenic dizziness. Cervicogenic
dizziness can be seen in association with flexion-extension (whiplash) injuries, severe
cervical arthritis, herniated cervical disks, and head trauma, especially blunt trauma to
the top of the head.
2. The cervico-ocular reflex, an eye movement response to neck movement, is thought
to be of minimal importance in normal individuals. However, a patient who has
sustained a neck injury may have an abnormal or exaggerated cervico-ocular reflex that
causes dizziness or disequilibrium when the head is turned.
3. Neck muscle spasm and pain are often associated with symptoms of dizziness. The
cause-and-effect relationship between these two symptoms is uncertain. In fact,
patients with cervicogenic dizziness may experience a ‘‘vicious cycle’’ of excessive
neck muscle activity exacerbating their dizziness, which subsequently exacerbates their
neck discomfort.
4. Treatment of cervicogenic dizziness includes muscle relaxants and physical therapy
to improve range of motion of the neck and to reduce neck muscle spasm and
discomfort. Use of a cervical collar should be limited to 1 to 2 hours per day.

References
1. Brandt T, Bronstein AM: Cervical vertigo. J Neurol Psychiatry 71:8–12, 2001.
2. Ryan GMS, Cope S: Cervical vertigo. Lancet 2:1355–1358, 1955.
3. Jongkees LBW: Cervical vertigo. Laryngoscope 79:1473–1484, 1969.
4. Neuhuber WL, Zenker W: Central distribution of cervical primary afferents in the rat, with
emphasis on proprioceptive projections to vestibular, perihypoglossal, and upper thoracic
spinal nuclei. J Comp Neurol 280:231–253, 1989.
5. Huygen PLM, Verhagen WIM, Nicolasen MGM: Cervico-ocular reflex enhancement in
labyrinthine-defective and normal subjects. Exp Brain Res 87:457–464, 1991.
6. Barlow D, Freedman W: Cervico-ocular reflex in the normal adult. Acta Otolaryngol
89:487–496, 1980.
372 VESTIBULAR DISORDERS

7. Bronstein A, Hood J: The cervico-ocular reflex in normal subjects and patients with absent
vestibular function. Brain Res 373:399–408, 1986.
8. Oosterveld WJ, Kortschot HW, Kingma GG, de Jong HA, Saatci MR:
Electronystagmographic findings following cervical whiplash injuries. Acta Otolaryngol
(Stockh) 111:201–205, 1991.
9. De Jong PTV, Vianney de Jong JMB, Cohen B, Jongkees BW: Ataxia and nystagmus induced
by injection of local anesthetics in the neck. Ann Neurol 1:240–246, 1977.
10. Strupp M, Arbusow V, Dieterich M, Sautier W, Brandt T: Perceptual and oculomotor effects
of neck muscle vibration in vestibular neuritis. Ipsilateral somatosensory substitution of
vestibular function. Brain 121:677–685, 1998.
11. Wrisley DM, Sparto PJ, Whitney SL, Furman JM: Cervicogenic dizziness. J Orthop Sports
Phys Ther 30(12):755–766, 2000.
12. Fitz-Ritson D: Assessment of cervicogenic vertigo. J Manipulative Physiol Ther
14(3):193–198, 1991.
13. Malmstrom EM, Karlberg M, Melander A, Magnusson M, Moritz U: Cervicogenic
dizziness—musculoskeletal findings before and after treatment and long-term outcome.
Disability & Rehabilitation, 29(15):1193–1205, 2007.
Case 59
Acoustic Neuroma—
Management

What is controversial about the management of dizziness associated with acoustic neu-
roma? Treatment options for patients with an acoustic neuroma include observation,
stereotactic radiation (i.e., gamma knife), and conventional microsurgery. Dizziness can
be associated with each of these treatment options but the pattern of symptoms can vary
widely. Although vestibular hypofunction underlies most cases, optimal treatment requires
considering causes of impaired vestibular compensation and uncertain effects of radiation
of the vestibular labyrinth and nerve.

History

A 68-year-old woman presented with a complaint of dizziness and unsteadiness for several
months. The patient reported that these symptoms began about 6 months after undergoing
stereotactic radiation for treatment of a small acoustic neuroma. The patient’s acoustic
neuroma was discovered during evaluation of left-sided hearing loss and tinnitus. She
noticed minimal dizziness at the time the acoustic neuroma was diagnosed. The patient
now reports veering to the left when walking, especially in dimly lit environments. Her
symptoms are exacerbated by fatigue and exertion. Certain visual environments such as
store aisles and sidewalks bother her. The patient had been prescribed meclizine, but this
did not provide any relief. She also complained of a pressure sensation around the left eye
and blurred vision.
Question 1: What are the treatment options for small acoustic neuromas?
Answer 1: Treatment options for patients with a small acoustic neuroma include
observation, stereotactic radiation (i.e., gamma knife), and micro-surgical excision.
Selection of the appropriate treatment option depends on many factors and should
be individualized.1,2 The most important factors to consider include the size and
location of the tumor, the age and health of the patient, and the severity of
symptoms. For example, small tumors in older patients can be observed with
re-imaging over time to confirm stability of the tumor.3,4 Small tumors can be
safely removed surgically in all age groups but general health considerations limit
the use of surgery in older patients.5 Stereotactic radiation is an alternative
approach that has grown in popularity and is considered primarily in middle-aged

373
374 VESTIBULAR DISORDERS

and older patients with growing tumors that are small or medium sized. Large
tumors in all age groups generally require surgery. Some centers advocate subtotal
removal of larger tumors to limit morbidity to the cranial nerves.
Question 2: What is stereotactic radiation?
Answer 2: Stereotactic radiation involves the use of precisely directed doses of
radiation to treat tumors within the head while minimizing damage to surrounding
structures. The stereotactic radiation can be delivered in a single treatment session
(i.e., stereotactic radiosurgery) or can be delivered in several sessions (i.e., fractio-
nated stereotactic radiotherapy). The radiation dose is designed to injure or kill the
tumor cells or their supporting blood vessels. In the case of an acoustic neuroma,
the tumor does not disappear following radiation, but treatment success is defined
as no further tumor growth.6 An example of a radiation treatment plan is shown in
Case 59: Figure 1.

Physical Examination

Neurologic examination was normal, with the exception of mild gait instability. The
patient could not tandem walk. Vibratory sense at the ankles was normal. Otologic
examination revealed that Weber’s test lateralized to the right, and the Rinne test was

Case 59: Figure 1 Example of a Leksell Gamma Knife Treatment Plan for delivering
stereotactic radiation to an acoustic neuroma. The concentric lines that outline the tumor are
50% and 30% isodose curves that represent the distribution of radiation.
 CASE 59: ACOUSTIC NEUROMA—MANAGEMENT 375

positive bilaterally. Audibility of a finger rub was reduced on the left side. Neurotologic
examination revealed no spontaneous nystagmus using infrared goggles. The head thrust
was normal in both directions. A low-amplitude right-beating post-head-shake nystagmus
was noted. The patient was unable to maintain her balance while standing on a compliant
foam pad with the eyes closed.
Question 3: What is the significance of the patient’s physical examination abnormalities?
Answer 3: The patient’s physical examination confirms a hearing loss on the left.
Additionally, the normal head thrust suggests a preserved or partially preserved
VOR bilaterally. Despite this evidence of preserved vestibular function, the patient’s
post-head-shake nystagmus suggests an ongoing vestibular asymmetry. The
patient’s inability to stand on a compliant foam pad with the eyes closed, inability
to tandem walk, and mildly abnormal stepping test suggest a problem in the
vestibulospinal system. Taken together, these findings suggest uncompensated
vestibular dysfunction.

Laboratory Testing

Videonystagmography: Ocular motor testing was normal, and there was no spontaneous or
positional nystagmus. Caloric testing showed no response to warm and cold irrigations
bilaterally. Ice-water responses were present bilaterally.
Rotational testing revealed a decreased magnitude of responses (low gain) with a mild
right directional preponderance.
Vestibular-evoked myogenic potentials were normal on the right and absent on the left.
Posturography testing revealed falls on conditions 5 and 6, indicating a vestibular loss
pattern.
Audiometric testing revealed a mild high-frequency sensorineural hearing loss in the
right ear. The left ear showed a profound sensorineural hearing loss, with a pure tone
average of 72 dB and 0% word recognition.
An MRI scan of the brain revealed a neoplasm that filled the left internal auditory canal
and extended into the cerebellopontine angle less than 1 cm (Case 59: Figure 2). The
neoplasm was consistent with an acoustic neuroma. Comparison with the pretreatment
study showed no tumor growth. The brain appeared normal.
Question 4: What is the significance of the laboratory test results?
Answer 4: The vestibular laboratory test results revealed a bilaterally reduced VOR,
vestibulo-ocular asymmetry, and vestibulospinal dysfunction. The caloric reduction
on the left is not surprising, as unilateral caloric weakness is commonly associated
with acoustic neuroma. However, the caloric reduction on the unaffected right side
is unexpected and may be due to a preexisting unrelated peripheral vestibular loss
or may possibly be the result of central cerebellar inhibition. The reduced gains on
rotational chair testing corroborate the results of caloric testing and suggest that
overall vestibular sensitivity is reduced, possibly as a result of cerebellar inhibition.
The alertness of the patient during testing and the possible use of vestibular-
suppressant medications should be checked.
Rotational testing also suggests an ongoing VOR asymmetry in agreement with
the presence of post-head-shake nystagmus on physical examination. Posturography
testing suggests an inability to use vestibular information to maintain upright
balance and is consistent with the patient’s inability to stand on a compliant foam
376 VESTIBULAR DISORDERS

Case 59: Figure 2 Axial, T1 weighted with gadolinium enhancement MRI of the brain showing
a cerebellar-pontine angle neoplasm involving the left internal auditory canal consistent with an
Acoustic Neuroma.

pad with the eyes closed during physical examination. The normal ocular motor
test and normal MRI of the brain suggest that there is no significant neurologic
dysfunction. This agrees with the patient’s normal neurologic examination aside
from difficulty with upright balance.
The laboratory test results are in agreement with the physical exam and suggest
uncompensated vestibular dysfunction.
Question 5: What are the possible causes for this patient’s ongoing vestibular dysfunction
and poor compensation?
Answer 5: The onset of new vestibular symptoms following stereotactic irradiation
of an acoustic neuroma has been reported to occur in 29% of patients, typically
beginning 6 months after treatment.6 This report is consistent with a larger study of
patients undergoing stereotactic radiation in which 40% of patients presented with
vestibular symptoms prior to treatment and 30% of patients reported new vestib-
ular symptoms (disequilibrium, not episodic vertigo) after treatment.7 Changes in
caloric function were also assessed after treatment and showed a spectrum of
changes with some patients showing decreased function and others showing
improved function.7
These results suggest that many patients note disequilibrium prior to treatment
and this is likely due to vestibular hypofunction. However, new vestibular symp-
toms also commonly occur following treatment, and multiple causes are possible
and not known with certainty. New and ongoing vestibular symptoms may be due
 CASE 59: ACOUSTIC NEUROMA—MANAGEMENT 377

to fluctuating vestibular function, decreasing vestibular function, or aberrant activ-

ity in the vestibular nerve or vestibular labyrinth. The aberrant activity could be a
result of ongoing radiation-induced neuritis causing axonal demyelination and
neural fibrosis, or a result of metabolic changes within the inner ear. These effects
could be caused by radiation-induced vasculitis or by direct effects on the eighth
nerve. Other causes of impaired vestibular compensation must be considered and
include a central nervous system abnormality, involvement of the contralateral
vestibular system causing a bilateral vestibular loss, multiple sensory deficits, a
sedentary lifestyle, and vestibular-suppressant medications (see Case 3).

Diagnosis/Differential Diagnosis

This patient was given a diagnosis of impaired vestibular compensation as a result of

peripheral vestibular function associated with prior stereotactic radiation.

Treatment/Management

Question 6: What are the treatment options for this patient?

Answer 6: Treatment options for this patient include a trial of a vestibular-suppres-
sant medication, a trial of vestibular rehabilitation, and ablation of the left labyrinth.
In general, the use of vestibular-suppressant medications in a patient with bilaterally
reduced vestibular-sensitivity is not likely to be effective and may worsen the
symptoms. However, in the special situation where aberrant peripheral vestibular
function is suspected to be causing a centrally mediated reduction in overall
vestibular sensitivity, the use of a benzodiazepine-class suppressant might prove
beneficial. A course of aggressive vestibular rehabilitation should be tried.8
Treatment with a low dose of a benzodiazepine in combination with vestibular
rehabilitation might prove beneficial. Ablation of the left labyrinth or surgical
removal of the tumor can be considered if the patient fails to gain benefit from
these interventions.

Follow-Up

The patient was treated first with a course of vestibular rehabilitation and then with a
combination of clonazepam, 0.25 mg twice daily, and vestibular exercises. At a follow-up
evaluation visit 3 months later, the patient’s symptoms were unchanged and continued to
be debilitating. The patient then underwent a transmastoid labyrinthectomy to ablate
vestibular function in the tumor-affected ear. Postoperatively, the patient’s symptoms
gradually improved but never resolved completely. Several months following surgery,
the patient complained of dizziness only with rapid head movements and still noticed
difficulty walking in dimly lit environments.

Summary

A 68-year-old woman presented with dizziness 2 years following stereotactic radiation for
an acoustic neuroma. Physical examination and laboratory tests suggested impaired
378 VESTIBULAR DISORDERS

vestibular compensation. The patient’s symptoms, which also included disequilibrium,

were not relieved by meclizine or a benzodiazepine. Following an unsuccessful trial of
vestibular rehabilitation and clonazepam therapy, the patient underwent a transmastoid
labyrinthectomy. Postoperatively, her dizziness was much reduced, although she remained
symptomatic with rapid head movements.

Teaching Points

1. The most common treatment of patients with acoustic neuroma is microsurgical

excision of the tumor. Other treatment options include observation, planned subtotal
removal, and stereotactic irradiation. Selection of the appropriate treatment option
depends on many factors and should be individualized.
2. Dizziness occurs more commonly after stereotactic irradiation in patients with
normal pretreatment vestibular function. Patients should be counseled regarding the
occurrence of vestibular symptoms following stereotactic irradiation.
3. Dizziness following stereotactic irradiation may be related to reduced or aberrant
vestibular nerve activity. Symptoms may persist as a result of impaired vestibular
compensation.
4. A treatment option for patients with presumed aberrant peripheral vestibular
function is peripheral vestibular ablation.

References
1. Pogodzinski MS, Harner SG, Link MJ: Patient choice in treatment of vestibular schwannoma.
Otolaryngol Head Neck Surg 130(5):611–616, 2004.
2. Pollock BE, Driscoll CL, Foote RL, Link MJ, Gorman DA, Bauch CD, Mandrekar JN, Krecke
KN, Johnson CH: Patient outcomes after vestibular schwannoma management: A prospective
comparison of microsurgical resection and stereotactic radiosurgery. Neurosurgery
59(1):77–85, 2006.
3. Strasnick B, Glasscock ME, Haynes D, McMenomey SO, Minor LB: The natural history of
untreated acoustic neuromas. Laryngoscope 104:1115–1119, 1994.
4. Stangerup SE, Caye-Thomasen P, Tos M, Thomsen J: The natural history of vestibular
schwannoma. Otol Neurotol 27(4):547–552, 2006.
5. Wiet RJ, Zappia JJ, Hecht CS, O’Connor CA: Conservative management of patients with
small acoustic tumors. Laryngoscope 105:795–800, 1995.
6. Lunsford LD, Linskey ME, Flickinger JC: Stereotactic radiosurgery for acoustic nerve sheath
tumors. In: Tos M, Thompson J (eds). Proceedings of the First International Conference on
Acoustic Neuroma. Amsterdam: Kugler, 1992, pp 279–287.
7. Wackym PA, Runge-Samuelson CL, Poetker DM, Michel MA, Burg,LS, Firszt, JB: Gamma
knife radiosurgery for acoustic neuromas performed by a neurotogist: Early experiences and
outcomes. Otology and Neurotology 25:752–761, 2005.
8. Vereeck L, Wuyts FL, Truijen S, DeValck C, Van de Heyning PH: The effect of early
customized vestibular rehabilitation on balance after acoustic neuroma resection. Clin Rehabil
22:698–713, 2008.
Case 60
Perilymphatic Fistula

What is controversial about a perilymphatic fistula? The presence of a perilymphatic fistula

is often impossible to confirm or rule out. Thus, it is usually difficult to determine
definitively which patients have such a diagnosis. This diagnostic uncertainty leads to
difficulties in appropriate management. Specifically, should patients whose history sug-
gests a perilymphatic fistula undergo exploratory surgery?

History

A 42-year-old female social worker presented with a chief complaint of dizziness that she
described as a sense of lightheadedness that worsened with rapid head movements.
Dizziness was present daily and was exacerbated by bending, coughing, and sneezing,
and occasionally by bowel movements. The patient also reported hearing loss and
tinnitus in the left ear. She dated the onset of her symptoms to head trauma sustained
14 months earlier during a family dispute. The patient was reluctant to provide details of
this event. She had no significant past medical history other than the head trauma and was
not using any medications prior to her dizziness. The family history was noncontributory.
The patient’s evaluation by her primary care physician included a normal CT scan.
Meclizine was prescribed and provided some benefit, but the patient continued to be
symptomatic.
Question 1: Based on the patient’s history, what are the diagnostic considerations in this case?
Answer 1: Although this patient does not report episodic vertigo, her complaint
of dizziness worsened by head movements is suggestive of a peripheral vestibular
disorder. The associated unilateral auditory symptoms suggest involvement of
the inner ear as well. Because her symptoms followed head trauma, diagnostic
considerations include labyrinthine concussion, post-traumatic endolymphatic
hydrops, and perilymphatic fistula. The symptoms worsened with Valsalva maneu-
vers, which is particularly suggestive of perilymphatic fistula.

Physical Examination

The patient had full extraocular movements but was noted to have an exophoria, that is, a
latent ocular lateral misalignment when fusion was broken. There was no nystagmus. She
had decreased pinprick sensation on the left side of her face that did not follow a

379
380 VESTIBULAR DISORDERS

dermatomal pattern but, according to the patient, corresponded to the region injured in the
trauma 14 months prior to evaluation. She had normal strength and extremity sensation and
normal coordination. Her gait was normal except for slight difficulty with tandem walking.
Romberg’s test was negative.
On otologic examination, the left eardrum had a normal appearance, but within the
middle ear space the incus appeared to be dislocated. The long process of the incus had
moved laterally and anteriorly from its normal position. The right ear appeared normal.
On tuning fork examination, the Rinne test was negative on the left and positive on the
right. Weber’s test revealed lateralization to the left. On neurotologic examination,
there was no nystagmus using infrared glasses. The head thrust was normal. There was
no post-head-shaking nystagmus or positional nystagmus. On pneumatic otoscopy the
eardrum was freely mobile, and with repeated pressure changes the patient began to feel
dizzy and nauseous. No nystagmus was observed during pneumatic otoscopy, tragal
stimulation, or Valsalva maneuvers. The patient had great difficulty standing on a
compliant foam surface with her eyes open and could not stand on foam at all with
her eyes closed.
Question 2: Based on the history and physical examination, what is this patient’s likely
diagnosis and what further laboratory testing is indicated?
Answer 2: This patient has a post-traumatic peripheral vestibulopathy that may
be caused by labyrinthine concussion or perilymphatic fistula and traumatic
ossicular chain disruption. The tuning fork examination and otoscopy suggest
the presence of a conductive hearing loss on the left, probably as a result of
dislocation of the incus. The association of ongoing dizziness and traumatic
dislocation of the incus raises the possibility of additional ossicular dislocation
involving the stapes and possible perilymphatic fistula involving the oval win-
dow. Appropriate laboratory testing includes audiometry and vestibular labora-
tory studies to document the character and extent of injury and to serve as a
baseline should the patient require surgery for repair of the ossicular chain
dislocation or perilymphatic fistula.

Laboratory Testing

Videonystagmography: Ocular motor function was normal. There was no spontaneous or

positional nystagmus. Caloric testing revealed a borderline normal left reduced vestibular
response of 21%
Rotational testing revealed a left directional preponderance.
Posturography indicated excessive sway on conditions 4, 5, and 6, that is, a surface
dependence pattern.
An audiogram revealed normal hearing in the right ear. The left ear had a mixed conductive
and sensorineural hearing loss with preserved word recognition (Case 60: Figure 1).

Diagnosis/Differential Diagnosis

Question 3: Based on the additional information from laboratory testing, what is the
patient’s likely diagnosis and what course of management should be taken?
Answer 3: The presence of a conductive hearing loss on audiologic testing
supports the impression of a traumatic ossicular chain disruption. The
 CASE 60: PERILYMPHATIC FISTULA 381

Case 60: Figure 1 Audiogram.

sensorineural portion of the hearing loss raises the possibility that the cochlea
also was damaged. The sensorineural hearing loss could have been caused by
labyrinthine concussion or perilymphatic fistula. The results of vestibular testing
support the presence of ongoing vestibular system dysfunction, and the unilat-
eral caloric weakness supports a peripheral vestibulopathy as the cause. The
vestibular symptoms and signs could be the result of either a perilymphatic
fistula or labyrinthine concussion.
Surgical exploration of the middle ear is indicated to restore hearing by recon-
structing the ossicular chain and to rule out a perilymphatic fistula as a cause of the
continuing vestibular symptoms.
Question 4: What is a perilymphatic fistula?
Answer 4: A perilymphatic fistula is an abnormal connection between the middle
and inner ear spaces, specifically between the air-filled middle ear and the
perilymphatic space of the inner ear.1 A perilymphatic fistula can occur through
the bony labyrinth (so-called bony fistula); through the oval window (so-called
oval window fistula); or through the round window (so-called round window
fistula) (Case 60: Figure 2).
Question 5: What are the common presenting symptoms and signs of perilymphatic fistula?
Answer 5: Common presenting symptoms and signs of perilymphatic fistula include
sensorineural hearing loss that is often fluctuating but may be constant or progres-
sive, and tinnitus.2 Vestibular symptoms are usually nonspecific and include mild
unsteadiness and disequilibrium. Occasionally, patients with perilymphatic fistula
382 VESTIBULAR DISORDERS

Case 60: Figure 2 Schematic drawing of the middle and inner ears showing common sites of
perilymphatic fistulas. Curved arrows highlight the movement of perilymph through the round
window membrane, the oval window, and a semicircular canal fistula.
Modified with permission from Glasscock, ME, et al: Handbook of Vertigo. New York: Raven Press,
1990.15

report vertigo, especially during Valsalva maneuvers (coughing, sneezing, bending,

lifting, or straining at stool). Perilymphatic fistula should be considered in patients
(usually children) with a history of recurrent meningitis or progressive sensorineural
hearing loss following an episode of otitis media.3 Although it is possible that
perilymphatic fistula can cause a pure vestibular syndrome without auditory or
aural symptoms, the prevalence of this entity is controversial. Because it is not
possible to diagnose a perilymphatic fistula solely on the basis of vestibular symp-
toms, most clinicians require a history of a traumatic inciting event and clear
lateralization, for example, by the presence of hearing loss, to consider the diag-
nosis of a perilymphatic fistula.
Question 6: What are the causes of perilymphatic fistula?
Answer 6: Perilymphatic fistula can be iatrogenic, traumatic, erosive, sponta-
neous, or congenital. Iatrogenic fistulas are most commonly associated with
surgery involving the stapes, in particular stapedectomy in patients with oto-
sclersosis and during ossicular chain reconstruction. Traumatic perilymphatic
fistula can be a result of direct penetrating injury; indirect injury following blunt
head trauma, which probably accounts for this patient’s perilymphatic fistula; or
barotrauma.4–6 Air seen within the labyrinth on CT imaging (pneumolabyrinth)
suggests the presence of a perilymphatic fistula or fracture of the otic capsule.7,8
Erosive perilymphatic fistula usually is caused by chronic middle ear and mastoid
infection with an associated cholesteatoma (see Case 43) or, rarely, neoplasia.
Spontaneous perilymphatic fistulas are highly controversial unless a congenital
inner ear malformation is present.9 Perilymphatic fistula related to a congenital
inner ear or middle ear malformation can occur spontaneously or, more com-
monly, after minor head trauma or forced Valsalva maneuver. 10 It should be
noted that sudden changes in hearing and episodes of vertigo commonly occur
in children with congenital inner ear malformations the (See Case 48) that are
not necessarily related to perilymphatic fistula formation.11,12
This patient was given a diagnosis of a post-traumatic perilymphatic fistula.
 CASE 60: PERILYMPHATIC FISTULA 383

Treatment/Management

A suspected perilymphatic fistula can be initially treated with a period of bed rest and
reduced activity. Persistence of symptoms or deterioration of hearing are indications for
surgical middle ear exploration. Because this patient also had evidence of ossicular chain
dislocation, a middle ear exploration was performed without delay.
Middle ear exploration is usually performed under local anesthesia. Using an operating
microscope, the tympanic membrane is reflected open, and the ossicular chain and oval and
round window membranes are inspected directly. Perilymphatic fistula can be confirmed
by visualizing a tear, rupture, or fracture of one of the inner ear membranes. In the past, the
observation of clear fluid ‘‘pooling’’ around the inner ear membranes had been considered
evidence of a perilymphatic fistula. However, it is now known that this sign is highly
inaccurate. Specific assays for detecting perilymph have been studied, the most promising
being the beta-2 transferrin assay, but have not yet been proven to be clinically reliable.13,14
In this patient, the incus was found to be severely dislocated; the annular ligament of the
stapes was torn, and the stapes was partially subluxed into the vestibule. Repair was
performed by first removing the incus. The stapes was then lifted back into its proper
position, and a fascial graft was used to seal the ruptured annular ligament. The incus was
then repositioned in the middle ear to reconstruct the ossicular chain.
After this procedure, the patient had complete restoration of the conductive component
of her hearing loss, and she has had no further dizziness. The patient was advised to avoid
exposure to changes in barometric pressure such as scuba diving, hiking at high altitude, or
sky diving.

Summary

A 42-year-old woman complained of dizziness following blunt head trauma. The patient
had associated mild hearing loss and tinnitus in the left ear. Examination suggested damage
to the ossicular chain and possible perilymphatic fistula. Laboratory testing demonstrated a
mixed conductive and sensorineural hearing loss and a vestibular reduction on the left. The
patient underwent middle ear exploration with repair of an oval window fistula and
ossicular chain reconstruction.

Teaching Points

1. Peripheral vestibular-related symptoms following head trauma can be caused by

labyrinthine concussion, post-traumatic endolymphatic hydrops, and
perilymphatic fistula.
2. A perilymphatic fistula is an abnormal connection between the middle and inner
ear spaces. It can result from a fistula of the bony labyrinth, a rupture of the oval
window, or a rupture of the round window.
3. Symptoms and signs of perilymphatic fistula include sensorineural hearing loss
that is often fluctuating, but can be constant or progressive, and tinnitus. Vestibular
symptoms are usually nonspecific, including mild unsteadiness and disequilibrium.
Occasionally, patients with perilymphatic fistula report vertigo, especially during
Valsalva maneuvers (coughing, sneezing, bending, lifting, or straining at stool).
384 VESTIBULAR DISORDERS

4. The causes of perilymphatic fistula include iatrogenic, traumatic, erosive,

congenital, and spontaneous varieties. The occurrence of spontaneous perilymphatic
fistula is highly controversial unless a congenital inner ear malformation is present.
Perilymphatic fistula should be considered in patients (usually children) with a history
of recurrent meningitis or progressive sensorineural hearing loss following an episode of
otitis media.
5. The treatment of a suspected perilymphatic fistula includes a trial of bed rest and
reduced activity to allow natural healing of the fistula. Persistence of symptoms or
deterioration of hearing are indications for surgical middle ear exploration. The
purposes of surgical exploration are to confirm the presence of a fistula and to repair
the fistula using fascial grafts.

References

1. Bhansali SA: Perilymph fistula. Ear Nose Throat 68:11–26, 1989.

2. Hughes GB, Sismanis A, House JW: Is there consensus in perilymph fistula management?
Otolaryngol Head Neck Surg 102:111, 1990.
3. Bluestone CD: Otitis media and congenital perilymphatic fistula as a cause of sensorineural
hearing loss in children. Pediatr Infect Dis J 7:S141–S145, 1988.
4. Emmett JR, Shea JJ: Traumatic perilymph fistula. Laryngoscope 90:1513–1520, 1980.
5. Glasscock ME, McKennan KX, Levine SC: Persistent traumatic perilymph fistulas.
Laryngoscope 97:860–864, 1987.
6. Pullen FW: Perilymphatic fistula induced by barotrauma. Am J Otol 13:270–272, 1992.
7. Lao WW, Niparko JK: Assessment of changes in cochlear function with pneumolabyrinth
after middle ear trauma. Otol Neurotol 28(8):1013–1017, 2007.
8. Nishiike S, Hyo Y, Fukushima H: Stapediovestibular dislocation with pneumolabyrinth.
J Laryngol Otol 122(4):419–421, 2008.
9. Schuknecht HF: Mondini dysplasia: A clinical and pathological study. Ann Otol Rhinol
Laryngol 89(Suppl):3–23, 1980.
10. Weissman JL, Weber PC, Bluestone CD: Congenital perilymphatic fistula: Computed tomo-
graphy appearance of middle ear and inner ear anomalies. Otolaryngol Head Neck Surg
111(3 Pt1):243–249, 1994.
11. Colvin IB, Beale T, Harrop-Griffiths K: Long-term follow-up of hearing loss in children and
young adults with enlarged vestibular aqueducts: Relationship to radiologic findings and
Pendred syndrome diagnosis. Laryngoscope 116(11):2027–2036, 2006.
12. Madden C, Halsted M, Benton C, Greinwald J, Choo D: Enlarged vestibular aqueduct
syndrome in the pediatric population. Otol Neurotol 24(4):625–632, 2003.
13. Bassiouny M, Hirsch BE, Kelly RH, Kamerer DB, Cass SP: Beta 2 transferrin application in
otology. Am J Otol 13:552–555, 1992.
14. Skedros DG, Cass SP, Hirsch BE, Kelly RH: Sources of errors in use of beta 2 transferrin
analysis for diagnosing perilymphatic and cerebral spinal fluid leaks. Otolaryngol Head Neck
Surg 109:861–864, 1993.
15. Glasscock, ME, Cueva RA, Thedinger BA: Handbook of Vertigo. New York: Raven Press, 1990.
Case 61
Vascular Cross-Compression
Syndrome of the Eighth
Cranial Nerve

What is controversial about vascular cross-compression syndrome of the eighth cranial

nerve? The existence of vascular cross-compression of the eighth cranial nerve by large
loops of the anterior inferior cerebellar artery in the internal auditory canal is well known.
However, the clinical significance of small arteries and veins juxtaposed to the eighth
cranial nerve is uncertain. Thus, establishing such a diagnosis and recommending treat-
ment is challenging.

History

A 50-year-old man presented with a chief complaint of disequilibrium that was more or less
constant but was particularly exacerbated by lying on his right side. The patient experi-
enced a sense of motion that was not paroxysmal while lying on his right side. It lasted as
long as he maintained that position and became worse until he could no longer stay in that
position. The patient did not complain of hearing loss but did note occasional noise and
occasional sharp pain in his right ear. He had suffered from these symptoms for 2 years, and
the onset had been gradual. His past history was significant for a 3-day episode of flu-like
symptoms and vertigo 5 years before evaluation that was diagnosed as labyrinthitis.
Several weeks after that episode of vertigo, the patient’s symptoms had completely
resolved and he became asymptomatic for approximately 3 years. There was no other
medical history of significance. He had used multiple medications including meclizine,
diazepam, promethazine, lioresal, carbamazepine, and amitriptyline with minimal or no
benefit. The patient had been treated for presumed endolymphatic hydrops with a combi-
nation of hydrochlorothiazide and triamterene and a salt-restricted diet with no benefit.
There was a family history of trigeminal neuralgia in the patient’s mother. The patient was
extremely troubled by his symptoms and had discontinued his work as an accountant.
Question 1: Based on the patient’s history, what are the diagnostic possibilities?
Answer: This patient’s history is unusual. The symptoms are positional but are not
characterized by vertigo and are not paroxysmal. Thus, benign paroxysmal posi-
tional vertigo is unlikely. However, the patient’s history is consistent with a periph-
eral vestibular ailment because of the ear pain, tinnitus, and past history of an acute

385
386 VESTIBULAR DISORDERS

vestibular syndrome. The vestibular abnormality is probably on the right, consider-

ing the laterality of the otologic symptoms and the exacerbation while lying on the
right side. Experience has shown that patients who can identify a side that elicits
symptoms when dependent often have their abnormality on the ipsilateral side.
The patient’s history does not, however, fit into a common diagnostic category.
Physical examination and laboratory testing may help to establish a diagnosis.

Physical Examination

The patient’s general examination was normal. Neurologic examination was normal, with
the exception of mild instability during tandem walking. Otologic examination was
normal. Neurotologic examination revealed no spontaneous nystagmus and normal Dix-
Hallpike maneuvers. Static positional testing using infrared goggles revealed that the
patient had a strong sense of disequilibrium while lying on his right side and a weak left-
beating nystagmus. The patient could not maintain balance while standing on a compliant
foam surface with the eyes closed.

Laboratory Testing

Videonystagmography: Ocular motor function was normal. There was a low-amplitude

left-beating nystagmus in the head-right and right-lateral positions of 4 degrees per second.
There was a 22% right reduced vestibular response during caloric testing.
Rotational testing was normal.
Posturography indicated excessive sway on conditions 5 and 6, that is, a vestibular
pattern.
VEMPs were slightly asymmetric, decreased on the right.
An audiogram revealed a mild high-frequency sensorineural hearing loss in the right ear,
with normal hearing in the left ear. Word recognition was excellent bilaterally, with normal
acoustic reflexes.
An MRI scan of the brain was normal.

Diagnosis/Differential Diagnosis

Question 2: Based on the patient’s history, physical examination, and laboratory studies,
what is the differential diagnosis?
Answer 2: This patient is likely to have a peripheral vestibulopathy on the right,
possibly as a result of the viral syndrome and ‘‘labyrinthitis’’ 5 years before evalua-
tion, which was probably a viral vestibular neuritis. The patient has evidence of an
ongoing vestibulospinal abnormality and a very low amplitude positional nystag-
mus, all consistent with an ongoing vestibular system abnormality. The precise
diagnosis cannot be stated with certainty. In light of the patient’s family history of
trigeminal neuralgia and personal history of atypical ear pain associated with
chronic dizziness, the possibility of a vascular cross-compression syndrome affect-
ing the eighth cranial nerve should be considered.1 The clinical description of this
condition is controversial, with no agreed-on set of diagnostic criteria.2 Indeed, for
some experts, this condition does not even exist. However, recent histopathologic
evidence suggests that small regions of the vestibular nerve can become
 CASE 61: VASCULAR CROSS-COMPRESSION SYNDROME OF THE EIGHTH CRANIAL NERVE 387

demyelinated following an insult such as a viral infection, and these regions could
then become susceptible to irritation by adjacent blood vessels.3,4 An example of a
vascular loop seen on MRI is shown in Case 61: Figure 1. Note that the patient
discussed in the present case had a normal MRI. Vascular cross-compression
syndrome of the eighth cranial nerve has been called disabling positional vertigo
by Jannetta5 and vestibular paroxysmia by Brandt et al.6,7
This patient was given the diagnosis of vascular cross-compression syndrome of
the eighth cranial nerve.

Treatment/Management

Question 3: What treatments have been advocated for patients diagnosed with suspected
vascular cross-compression syndrome of the eighth cranial nerve?
Answer 3: Treatment of suspected vascular compression syndrome of the eighth
cranial nerve includes medications known to be effective for other disorders
thought to result from vascular compression, such as tic douloureux and

Case 61: Figure 1 T2 weighted axial MRI of the brain. The arrow points to a vascular loop
contacting the eighth cranial nerve in the right internal auditory canal.
388 VESTIBULAR DISORDERS

glossopharyngeal neuralgia. These agents include carbamazepine,6,7 baclofen, and

gabapentin. Other medications that are often prescribed for this condition include
vestibular suppressants such as diazepam. Surgical treatment has been advocated
for suspected vascular cross-compression syndrome of the eighth cranial nerve
using microvascular decompression.5 We suggest a trial of medical therapy before
considering surgery.
This patient was treated with gabapentin and was much improved symptomatically.

Summary

A 50-year-old man presented with the chief complaint of a sense of disequilibrium that was
exacerbated by prolonged recumbency with the right side down. The patient’s history was
significant for an acute vestibular syndrome probably of viral origin 5 years previously.
The patient had no signs or symptoms of paroxysmal positional nystagmus. Audiometric
and vestibular testing suggested a right-sided peripheral vestibular lesion. MRI scan was
negative. The patient was given a diagnosis of possible vascular cross-compression
syndrome of the eighth cranial nerve. He was treated with gabapentin, and his symptoms
resolved almost completely.

Teaching Points

1. Small regions of the vestibular nerve can become demyelinated following an insult
such as a viral infection, and these regions can then become susceptible to irritation
by adjacent blood vessels.
2. Vascular cross-compression syndrome of the eighth cranial nerve, which has been
called disabling positional vertigo and vestibular paroxysmia, refers to a
cochleovestibular syndrome caused by compression of the eighth cranial nerve
by blood vessels within the cerebellopontine angle.
3. The clinical description of vascular cross-compression syndrome of the eighth
cranial nerve is controversial, with no agreed-on set of diagnostic criteria.
Features of this syndrome include dizziness associated with head movements or
particular head positions, tinnitus, hearing loss, and ear pain. A history of symptoms
consistent with a vascular compression syndrome such as trigeminal neuralgia supports
the diagnosis of vascular cross-compression syndrome of the eighth cranial nerve.
4. Treatment of vascular cross-compression syndrome of the eighth cranial nerve
includes pharmacotherapy with carbamazepine, baclofen, or gabapentin. Surgical
treatment consists of microvascular decompression. We advocate a trial of medical
therapy before referring a patient for a surgical opinion.

References
1. Moller MB, Moller AR, Jannetta PJ, Jho HD, Sekhar LN: Microvascular decompression of the
eighth nerve in patients with disabling positional vertigo: Selection criteria and operative
results in 207 patients. Acta Neurochir (Wien) 125:75–82, 1993.
2. Ryu H, Yamamoto S, Sugiyama K, Nozue M: Neurovascular compression syndrome of the
eighth cranial nerve. What are the most reliable diagnostic signs? Acta Neurochir (Wien)
140:1279–1286, 1998.
3. Schwaber MK, Whetsell WO: Cochleovestibular nerve compression syndrome. II. Vestibular
nerve histopathology and theory of pathophysiology. Laryngoscope 102:1030–1036, 1992.
CASE 61: VASCULAR CROSS-COMPRESSION SYNDROME OF THE EIGHTH CRANIAL NERVE 389

4. Colletti V, Fiorino FG, Carner M, Turazzi S: Vestibular neurectomy and microvascular

decompression of the cochlear nerve in Meniere’s disease. Skull Base Surg 4:65–71, 1994.
5. Jannetta PJ, Moller MB, Moller AR: Disabling positional vertigo. N Engl J Med
310:1700–1705, 1984.
6. Brandt TH, Dieterich M: Vestibular paroxysmia (disabling positional vertigo). Neuro-
Opththalmology 14:359–369, 1994.
7. Hufner K, Barresi D, Glaser M, Linn J, Adrion C, Mansmann U, Brandt T, Strupp M:
Vestibular paroxysmia: Diagnostic feathures and medical treatment. Neurology
71:1006–1014, 2008.
 Appendix of Diagnoses

Diagnosis/Condition Case No.

Acoustic neuroma 2, 59
Anterior inferior cerebellar artery syndrome 38
Anxiety disorder 5, 22, 25
Autoimmune inner ear disease 45
Benign paroxysmal positional vertigo 7, 23, 24, 25, 26, 28, 39
Benign recurrent paroxysmal vertigo of childhood 17
Bilateral vestibular loss 4, 44
Brainstem infarction 37, 38
Cerebellar degeneration 19
Cerebellar infarction 6
Cerebellopontine angle lesion 2, 59
Cervicogenic dizziness 58
Chiari malformation 34
Congenital nystagmus 50
Convergence spasm 31
Disequilibrium of aging 10
Drop attacks 40
Drug-induced dysequilibrium 18
Endolymphatic hydrops (Meniere’s disease) 9, 12, 20, 24, 29, 40, 42
Enlarged vestibular aqueduct syndrome 48
Herpes zoster oticus 41
Horizontal semicircular canal benign positional vertigo 28
Impaired vestibular compensation 3
Labyrinthine concussion 13, 21, 50
Lithium-induced dizziness 47
Mal de débarquement syndrome 36
Malformation of the inner ear 48
Malingering 56
Meniere’s disease (endolymphatic hydrops) 9, 12, 20, 24, 29, 40, 42
Migraine-related dizziness 8, 17, 20, 22, 23
Mild traumatic brain injury 14
Multiple sclerosis 30
Multisensory disequilibrium 11
Nonspecific vestibulopathy 16, 57
Ocular flutter 49
Orthostatic hypotension 27
Orthostatic tremor 35
Otitis media and cholesteatoma formation 43
Otosclerotic inner ear syndrome 51

390
 APPENDIX OF DIAGNOSES 391

Ototoxicity 4, 44
Perilymphatic fistula 43, 60
Posterior inferior cerebellar artery syndrome 37
Progressive supranuclear palsy 46
Psychiatric dizziness 5, 22, 25
Ramsay Hunt syndrome 41
Rotational vertebral artery syndrome 54
Sleep disorder 55
Solvent exposure 52
Superior semicircular canal dehiscence syndrome 32
Tullio’s phenomenon 32
Vascular cross compression syndrome of the eighth cranial nerve 61
Vertebrobasilar insufficiency 33
Vestibular neuritis 1, 3, 15
Wallenberg’s syndrome 37
Wernicke’s encephalopathy 53
 Index

Note: Page Numbers followed by f denotes Figures and t denotes Tables.

Acoustic neuroma. See Cerebellopontine angle AntivertTM. See Meclizine

neoplasms Anxiety disorders
Acoustic neuroma management, 373–78. benign paroxysmal positional vertigo and
See also Cerebellopontine angle diagnosis, differential diagnosis, 200–201
neoplasms history, 199
Acoustic reflex testing, 42–43 laboratory testing, 200
Acoustic trauma, 312–14, 317–19 management, 201
Acute vestibular neuritis. See Vestibular physical examination, 199–200
neuritis teaching points, 202
Acute vestibulopathy of uncertain etiology. described, 53, 56
See Vestibular neuritis diagnosis, differential diagnosis, 96, 208, 309
Acyclovir, 73, 280 management, 60, 62t
Agoraphobia, 56, 96 MARD (See Migraine-anxiety-related
AICA syndrome. See Anterior-inferior dizziness (MARD))
cerebellar artery (AICA) syndrome Astasia-abasia, 360
AIDS, 323t Atarax. See Hydroxyzine
Alcoholism, 346 AtaraxTM (Hydroxyzine), 60, 61t, 62t
Alexander’s law, 68, 69, 69f, 74, 345 AtivanTM (Lorazepam), 60t
Alport’s syndrome, 314 Audiogram, 41–42, 43f
Alprazolam, 296, 297 Auditory brainstem response testing, 43–44, 44f
Amantadine, 153 Auditory nerve anatomy, function, 41, 42f
Aminoglycoside ototoxicity, 87, 87f, 88t, Autoimmune inner ear disease, 88, 299–304
90, 296
AmitrilTM. See Amitriptyline Bacterial otomastoiditis, 99
Amitriptyline, 62t, 120t, 323t Balance assessment
Ampulla anatomy, function, 5, 6f, 7f functional, 48, 49t
Anterior-inferior cerebellar artery static, 48
(AICA) syndrome Barotrauma, 317, 319
diagnosis, differential diagnosis, 226t, 259, Behcet’s disease, 302t
262–64, 262f, 263f, 264t Bell’s phenomenon, 305
history, 261 Benadryl (diphenhydramine), 60, 61t
laboratory testing, 262 Benign paroxysmal positional vertigo
physical examination, 261–62 anxiety and (See under Anxiety disorders)
signs, symptoms, 226t, 241–42, 242f bilateral, 267
teaching points, 265 classification, 53, 54f
Anticonvulsants, 120t, 167 diagnosis, differential diagnosis, 108–11,
Antidepressants, 120t 110f, 111f, 150, 156, 166, 229, 239, 241,
Anti-nausea agents, 59–60, 60t 267, 349, 368

392
 INDEX 393

etiologies, 56 Cerebellar infarction, acute

history, 107, 266–68 diagnosis, differential diagnosis, 100–102, 102t
horizontal semicircular canal (See Horizontal follow-up, 101
semicircular canal benign paroxysmal history, 99
positional vertigo (HCBPPV)) laboratory testing, 100, 101f
laboratory testing, 108, 268–70, 269f physical examination, 99–100
management, 46, 60, 111–14, 113f teaching points, 103
Meniere’s disease and (See under treatment, 101
Meniere’s disease) Cerebellopontine angle neoplasms
migraine and (See under Migraine) acoustic neuroma management, 373–78
natural history, 114 diagnosis, differential diagnosis, 78–79
physical examination, 107–8, 268 history, 76, 130
recurrent, 205–7, 266, 271 laboratory testing, 77–78, 78f, 127
surgical management, 266–71 physical examination, 76–77
teaching points, 114–15, 271 signs, symptoms, 18
Benign paroxysmal vertigo of childhood. teaching points, 79–80
See under Vertigo Cerebellum
Benzodiazepines, 60, 60t, 83, 167. See also blood supply to, 242f, 263f
specific medications influence on central vestibular system, 14
Berg Balance Scale, 49t Cerebral infarctions, multiple, 305
Beta blockers, 120t, 167 Cerebrovascular accident (CVA), 67
Bilateral acoustic neuroma/ neurofibromatosis Cervicogenic dizziness, 185, 244,
type 2, 299 368–71. See also Head trauma,
Bipolar affective disorder, 309 CNS/labyrinthine/cervical injury
Bisphosphonates, 336 Cervicoocular reflex, 13, 370, 371
Blood supply CHARGE syndrome, 315
vertebrobasilar system, 241–43, 242f, Chemical labyrinthectomy, 283–84, 284f
262f, 265 Chiari malformation
vestibular labyrinth, 5, 6f diagnosis, differential diagnosis, 160, 162,
BonnineTM. See Meclizine 170, 230t, 247
Brainstem history, 159, 244
auditory-evoked potential testing, laboratory testing, 245–47, 246f
43–44, 44f management, 248
blood supply to, 242f, 263f physical examination, 244–45, 245f
disorders, driving and, 366 teaching points, 248
infarction, 99, 100, 150, 329 Chlordecone, 323t
Branchio-oto-renal syndrome, 315 Chlordiazepoxide (LibriumTM), 62t
Brandt-Daroff exercises, 113, 113f, 207 Cholesteatoma, ear, 289–94, 290f
Chronic fatigue syndrome, 309
Calcium channel blockers, 120t Circulation abnormality. See Vertebrobasilar
Caloric testing insufficiency
applications of, 30, 37 Clinical Test of Sensory Integration and
described, 32–34, 32f, 33f Balance (CTSIB), 49t
Camptocormia, 360 Clinician’s dismissive behaviors, 57
Canalithiasis, 109–11 Clonazepam, 60t–62t, 96, 113
Central nervous system vasculitis, 305 in acoustic neuroma management, 377
Cerebellar artery syndromes, 226t MARD, 188
Cerebellar degeneration migraine, 120t
diagnosis, differential diagnosis, 171–73, 172t vestibulopathy of unknown cause, 161
history, 169–70 Cochlea anatomy, function, 5, 6f, 41, 42f
laboratory testing, 170–71, 171f Cochlear duct anatomy, function, 41, 42f
management, 173 Cochlear otosclerosis, 334f, 336–37
physical examination, 170 Cochlear-saccular dysgenesis, 314
teaching points, 173–74 Cogan’s syndrome, 299, 302, 302t
394 INDEX

CompazineTM, 59, 60, 61t, 127 Dizziness Handicap Inventory, 48

Complementary and alternative medicine, Doll’s eyes, 305
63, 63t Dopamine, 59
Connexin 26 gene, 313 DramamineTM. See Dimenhydrinate
Convergence insufficiency, 25, 231 Driving, dizziness and, 363–67
Convergence spasm, 25, 229–32 Drop attacks, 273–76
Corticosteroids, 72, 143–44 Dynamic Gait Index, 49t
Cranial nerve VIII (vestibulocochlear) Dysmetria, 257
abnormality effects, 44, 225f
anatomy, function, 5, 9, 10f, 11f, 41, 42f Ear drum schematic, 290f
vascular cross-compression syndrome, 385–88 ElavilTM. See Amitriptyline
Cupula anatomy, function, 5, 6f, 7f Electrocochleography, 44–45, 45f
Cupulolithiasis, 109, 111, 268, 341 Electronystagmographic perilymphatic fistula
Cyclizine (MarezineTM), 61t test, 43
Cyclobenzaprine, 370 Electronystagmography, 32
Cytomegalovirus, 313 Electro-oculography, 31, 31f, 32
EndepTM. See Amitriptyline
Dandy’s syndrome, 87, 92 Endolymph anatomy, function, 5, 6f
Demyelination disorders, 67. See also Endolymphatic hydrops. See Meniere’s disease
Multiple sclerosis Endolymphatic sac surgery, 144–45, 144f
Depression, 56–57 Enlarged vestibular aqueduct syndrome, 316,
Dexamethasone, 143 317f, 319
Diabetes mellitus, insulin-dependent, 136–38 Epilepsy, 273–76
Diabetic retinopathy, 137 EquiTestTM device, 37, 38f
Diazepam, 60t–62t, 113, 199, 255, 323t Etidronate, 336
DiGeorge’s syndrome, 315
Dimenhydrinate (DramamineTM), 59, 60, 60t, 61t Fenestration surgery, 233
Diphenhydramine (Benadryl), 60, 61t Five times sit to stand test, 49t
Disequilibrium, drug-induced Fluoxetine, 117
diagnosis, differential diagnosis, 167–68, Functional reach, 49t
208, 230t
history, 166 GABA, 59
laboratory testing, 167 Gabapentin, 252
lithium-induced dizziness, 309–11, 323t Gait speed, 49t
management, 168 Gentamicin, 86, 88, 283, 295, 297
physical examination, 167 Glutamate, 59
teaching points, 168 Glycine, 59
Disequilibrium of aging Gufoni maneuver, 214
diagnosis, differential diagnosis, 132–33, 206
history, 130–31 Hair cells (maculae), 5–9, 7f–8f
laboratory testing, 131, 132f, 206, 251, 296 Head-fixed, body-turned maneuvers, 369, 369f
management, 133, 133t Head thrust test, 26–27
physical examination, 131, 205–6 Head trauma, CNS/labyrinthine/cervical injury,
teaching points, 133–34 182–85, 230t, 314, 328
Diuretics, 61 Hearing assessment, 22, 23t, 25
Dix-Hallpike test, 27f, 28, 31–32 acoustic reflex testing, 42–43
vertigo, benign paroxysmal positional, 109, audiogram, 41–42, 43f
110f, 112 brainstem auditory-evoked potential testing,
Dizziness 43–44, 44f
classification, 53–54, 54f electrocochleography, 44–45, 45f
diagnosis, differential diagnosis, 101–2, 102t tympanometry, 42–43
nonvestibular, 209, 210 word recognition, 41–42
patient history, 17–20, 18t–20t Hennebert sign/symptoms, 234, 237, 291
vestibular, 209, 210 Hepatitis, viral, 323t
 INDEX 395

Herpes zoster oticus. See Ramsay Hunt syndrome management, 150

Histamine, 59, 127 physical examination, 148, 380
HIV, 299 teaching points, 151
Home particle repositioning, 206–7 Labyrinthine fistula, 291–93
Horizontal ocular instability, 24, 24f Labyrinthine ischemia, 99, 108
Horizontal semicircular canal benign Labyrinthitis, 136–37, 290, 386
paroxysmal positional vertigo mumps, 314
(HCBPPV), 213–16, 214f, 215f, 267 serous, 289–90, 290f
Hunter’s syndrome, 314 Lateropulsion, 257–60
Hurler’s syndrome, 314 Leksell gamma knife treatment, 373–74, 374f,
Hydrochlorothiazide, 61, 127 376, 378
Hydroxyzine (AtaraxTM, VistarilTM), 60, 61t, 62t Lesions
Hypertension, 61, 130, 257 caloric testing (See Caloric testing)
Hyperventilation test, 95 impaired compensation for, 149
Hypothyroidism, 305 rehabilitation interventions, 49–51, 50t
visual–vestibular interaction testing, 36–37
Illegible E test, 27 Liberatory maneuver, 113
ImavateTM. See Imipramine LibriumTM. See Chlordiazepoxide
Imipramine, 62t, 154, 188, 323t, 364 Linkage mechanisms, 56, 96
Impaired compensation. See Vestibular neuritis Lithium-induced dizziness, 309–11, 323t
Inner ear malformations, congenital Lorazepam (AtivanTM), 60t
diagnosis, differential diagnosis, 317–18 Lyme disease, 279, 280, 299
history, 312–15 Lymphoma, 305
laboratory testing, 315–16, 316f, 317f
physical examination, 315 Macrosaccadic oscillations, 322t
teaching points, 318–19 Macro-square-wave jerks, 322t
Intratympanic steroid perfusion, 143–44 Maculae (hair cells), 5–6, 8f
Mal de dé barquement syndrome, 254–56
JanimineTM. See Imipramine Malingering, 359–62
Jongkees’ formula, 33, 33f MarezineTM. See Cyclizine
Meclizine, 59, 60, 60t, 61t
Keratitis, interstitial, 302 labyrinthine concussion, 150
Klippel-Feil syndrome, 315 labyrinthitis, 136–37
KlonipinTM. See Clonazepam Meniere’s disease, 81, 127
multiple sclerosis, 227
Laboratory testing, 30 in rehabilitation therapy, 47
caloric testing (See Caloric testing) vertigo, benign paroxysmal positional, 113
hearing, 41–45, 43f–45f vestibulopathy of unknown cause, 159
ocular motor testing, 31 Medications, 59–63, 60t–62t, 88t. See also
vestibulo-ocular, 30 specific medications
vestibulospinal, 30 disequilibrium (See Disequilibrium,
Labyrinth assessment drug-induced)
caloric testing (See Caloric testing) Meniere’s disease
rotational testing (See Rotational testing) ablative management, 282–88
Labyrinthectomy benign paroxysmal positional vertigo and,
chemical, 283–84, 284f 195–98
surgical, 284, 285f bilateral, 217–21, 219f, 286
Labyrinthine concussion. See also Head trauma, childhood, 162
CNS/labyrinthine/cervical injury classification, 53, 54f
diagnosis, differential diagnosis, 150, 267, diagnosis, differential diagnosis, 67, 81,
328, 359, 379 88, 123, 127, 141, 156, 233, 239, 241,
driving and, 366 283–87, 284f, 285f, 299, 349
history, 147 driving and, 366
laboratory testing, 148–50, 148f drop attacks, 273–76
396 INDEX

Meniere’s disease (Continued ) signs, symptoms, 18

etiology, 125–26 teaching points, 227
history, 99, 123–25, 124f, 127, 140, 314 Multiple system atrophy, 210
laboratory testing, 90, 126–27, 126f, 141, Multisensory disequilibrium, 136–39
283–86, 334 Mumps labyrinthitis, 314
management, 46, 61, 127–28, 141–45, 142f, Myasthenia gravis, 24
144f
migraine and, 177–80 Neck muscle spasm, 370, 371
physical examination, 44–45, 125–26, 140, Neck-related reflexes, 13
234, 282 Neoplasia
post-traumatic, 147, 150, 229, 368, 379 cerebellopontine angle (See Cerebellopontine
signs, symptoms, 41, 123–24, 124f angle neoplasms)
teaching points, 128, 145, 198, 288 diagnosis, differential diagnosis, 259, 305, 323
vestibular suppressants, 59–60, 60t etiologies, 44
Meniett device, 142–43, 142f, 220 paraneoplastic process, 170, 323t, 324
Meningioma. See Cerebellopontine angle signs, symptoms, 41
neoplasms Neurodegenerative syndromes,
Meningitis, 88, 314, 382 deafness-associated, 88
Methylchloroform, 341, 342 Neurofibromatosis type II (bilateral acoustic
Midbrain, function of, 307, 308 neuroma), 88
Middle ear exploration, 383 Neurologic linkage model, 56, 96
Migraine Neurotransmitters, 59
basilar artery, 178 Nicotinic acid, 127
benign paroxysmal positional vertigo and, Norepinephrine, 59
191–93 Nystagmus, 11f, 13–16
diagnosis, differential diagnosis, 67, Alexander’s law, 68, 69, 69f, 74
120, 241 assessment, 24–29, 26f, 27f
drop attacks, 273–76 Bruns’, 76, 77, 80
food provoking, 163, 164t caloric testing (See Caloric testing)
history, 117–18, 309, 363 congenital, 326–30, 328t
laboratory testing, 119, 119t, 334 defined, 321
management, 47, 61, 120, 120t, 121 directional preponderance, 36, 36f
nausea and malaise, physiologic basis for, 118 direction-changing positional, 340–42
physical examination, 118–19 downbeating, 244–45, 245f, 247, 248, 309–11
signs, symptoms, 18 dysrhythmia, 170
teaching points, 121 electro-oculography testing, 31, 31f
vestibular suppressants, 59–60, 60t etiologies, 43
Migraine-anxiety-related dizziness (MARD), gaze-evoked, 69, 246–48
186–89 HCBPPV, 212–13
Migraine equivalent, 118 jerk, 328
Modified Gait Abnormality Rating Scale, 49t pendular, 328–30
Mondini dysplasia, 314 periodic alternating, 255
Motion, sensing, 5, 6f–8f physical examination, 67–71, 69f, 70f
Motion sickness, 117–18 positional testing, 27–28, 27f, 31–32
Motor control testing, 37 recovery, 124
Mucopolysaccharide storage disease, 314 rotational testing (See Rotational testing)
Multiple sclerosis upbeating, etiologies, 345, 345t
comorbidities, 329 vestibular, 68–71, 70f, 74, 100, 247
diagnosis, differential diagnosis, 225–27,
226t, 230t, 259, 323t Ocular flutter, 321, 322, 322t, 324, 325
history, 99, 223 Ocular motor testing, 31
laboratory testing, 224–25, 224f, 225f Opsoclonus, 322, 322t, 325
management, 227 Organophosphates, 323t
physical examination, 223–24, 245 Orientation to gravity, sensing, 5, 6f
 INDEX 397

Ornithine transcarbamylase deficiency, 162 Perilymphatic fistula

Orthostatic hypotension, 208–11, 239 comorbidities, 318
Orthostatic tremor, 250–52, 251t diagnosis, differential diagnosis, 150, 234,
Oscillopsia, 365 314, 380–81
Osteogenesis imperfecta, 314 etiologies, 317, 382, 384
Otitis media, chronic, 289–93, 382 history, 147, 233, 315, 379
Otoconia, 8f, 9f laboratory testing, 380, 381f
Otolithic membrane, 5, 8f management, 383, 384
Otolithic organs physical examination, 379–80
anatomy, function, 5, 6f signs, symptoms, 381–83, 382f
vestibular injury effects, 13, 15f, 24 teaching points, 383–84
Otosclerosis Peripheral neuropathy, 137
diagnosis, differential diagnosis, 88, 299 PhenegranTM. See Promethazine
history, 331 Phenelzine, 323t
laboratory testing, 332–35, 333f, 334f Phenytoin, 323t
management, 335–36 Physical examination
physical examination, 331–32 components, 22, 23t
signs, symptoms, 41 neurologic, 22, 23t
teaching points, 336–37 neurotologic, 22, 23t, 26–29, 26f–28f
Otosclerotic inner ear syndrome. See ocular motor, 22–25, 24f
Otosclerosis otologic, 22, 23t, 25
Ototoxicity Physical Performance Test, 49t
aminoglycoside, 87, 87f, 88t, 90, 296 PICA syndrome. See Posterior-inferior
diagnosis, differential diagnosis, cerebellar artery (PICA) syndrome
299, 323t Pneumatic otoscopy, 29
history, 86–87, 217, 295 Polarization vector described, 5–6, 8f
laboratory testing, 88–90, 89f, 219 Polyarteritis nodosa, 302t
management, 90–91, 91t Positional alcohol nystagmus (PAN),
physical examination, 87–88, 87f, 88t, 218, 340–42
295–96 Positional testing, 27–28, 27f, 31–32
teaching points, 92–93 Post-concussion syndrome
Overshoot dysmetria, 257 diagnosis, differential diagnosis, 359
history, 152–53
Paget’s disease, 88 management, 47, 154
Panic attacks Posterior fossa lesions, 109, 239, 244
benign paroxysmal positional vertigo and, Posterior-inferior cerebellar artery (PICA)
199–202 syndrome
described, 54, 56 diagnosis, differential diagnosis, 226t, 259, 264t
history, 95, 159, 199 history, 257
laboratory testing, 95, 187 physical examination, 257–58
management, 60, 62t signs, symptoms, 226t, 241–42, 242f, 264t
Papaverine, 127 teaching points, 259–60
Paraneoplastic process, 170, 323t, 324 Postural hypotension, 273–76
Parenchymal cerebellar atrophy. See Cerebellar Posturography
degeneration applications of, 30, 360, 362
Parkinson’s disease, 305 clinical foam, 28–29, 28f
Paroxysmal positioning testing, 27f, 28, 31–32 described, 37–39, 38f, 39f
Particle-repositioning maneuver, 214, 215f sensory organization testing, 37, 38f
Pastpointing, 29 surface-dependent pattern abnormality, 37, 39f
Patient interviews, tips and methods, 17–20, sway referencing, 37, 38f, 132–33
18t–20t Prednisolone, 303
Pause cells, 324 Prednisone
Pendred’s syndrome, 314–16 Meniere’s disease, 283
Perilymph anatomy, function, 5, 6f ocular flutter, 324
398 INDEX

Prednisone (Continued ) Saccule

Ramsay Hunt syndrome, 280 anatomy, function, 5, 6f–8f
vestibular neuritis, 72 assessment, 34, 39
PresamineTM. See Imipramine Scopolamine, 60
Presbyastasis. See Disequilibrium of aging Selective serotonin reuptake inhibitors,
Prochlorperazine, 60, 61t disequilibrium-inducing, 167
Progressive supranuclear palsy, 305–8, Semicircular canals
306f, 307t anatomy, function, 5, 6f, 7f, 285f
Promethazine, 59, 60, 60t, 61t, 113 caloric testing (See Caloric testing)
Meniere’s disease, 127 fistula, 235, 236f, 291, 292
Ramsay Hunt syndrome, 280 plugging, 268, 269, 269f, 271
vestibulopathy of unknown cause, 161 vestibular injury effects, 13, 15f
Propranolol, 120t Sensorineural hearing loss in children,
Psychiatric disorders, 53–57, 54f, 96 313–14, 313t
Psychiatric dizziness, 54, 95 Sensory organization testing, 37, 38f
Psychiatric overlay, 55 Serotonin, 59
Psychological/behavioral mediation, 55 Serous labyrinthitis, 289–90, 290f
Psychosomatic mechanisms, 57, 96 Sertraline (ZoloftTM), 62t, 120t
Pure autonomic failure, 210 Sheibe dysplasia, 314
Pursuit testing, 25 Singular neurectomy, 268–69
Sjogren’s syndrome, 87, 88
Ramsay Hunt syndrome, 277–80, 279f Skew deviation, 24
Reduced vestibular response computation, 33, 33f SK-PramineTM. See Imipramine
Reflexes Sleep disorders, 353–55
acoustic, testing, 42–43 Social withdrawal, 56–57
cervicoocular, 13, 370, 371 Solvent exposure, 339–42
neck-related, 13 Somatopsychic mechanisms,
stapedius, 43 56–57, 96
vestibulo-colic, 13 Sopite syndrome, 365
vestibulo-ocular reflex (VOR) (See Sound transduction, mechanism, 5–6, 7f
Vestibulo-ocular reflex (VOR)) Space and motion discomfort, 56, 94, 199
vestibulospinal, 13 Spinocerebellar ataxias (SCA), 171–73, 172t.
Rehabilitation, 46–47 See also Cerebellar degeneration
assessment, 48, 49t Spiral ganglion anatomy, function, 41, 42f
basis, 47 Square-wave jerks, 322t
contraindications, 47 Stapedectomy, 337
interventions, 49–51, 50t Stapedius reflex, 43
medications, role in, 62, 62t Stenger’s test, 360
Meniere’s disease, 127 Stereotactic radiation, 373–74, 374f,
Reporting guidelines, 365, 366 376, 378
Rheumatoid arthritis, 302t Strabismus, 23–24
Rinne test, 25 Streptomycin, 88, 220
Romberg’s test, 28–29, 28f Striatonigral degeneration, 305
Rotation, sensing, 5, 6f–7f Striola, 8f
Rotational testing Strychnine, 323t
applications of, 30, 33, 37 Styrene, 341, 342
described, 34–37, 35f, 36f Superior semicircular canal dehiscence
directional preponderance, 36, 36f syndrome
Rotational vertebral artery syndrome, diagnosis, differential diagnosis, 335
349–52, 350f history, 233
laboratory testing, 234–36, 234f, 235f
Saccades testing, 25–27 management, 236–37
Saccadic fixation instability, 321–25, 322t physical examination, 234
Saccadic hypermetria/hypometria, 257 teaching points, 237
 INDEX 399

Sway referencing, 37, 38f, 132 –33, 354 signs, symptoms, 16, 240t
Syphilis, 88, 233, 299, 300 teaching points, 243
Systemic lupus erythematosus, 302t Vertebrobasilar system blood supply, 241–43,
242f, 262f, 265
Temporary threshold shift, 312–13, 318 Vertigo
Thallium, 323t assessment, 27f, 41
TiganTM. See Trimethobenzamine benign paroxysmal positional (See Benign
Timed ‘‘Up & Go,’’ 49t paroxysmal positional vertigo)
Tinnitus, 333 benign recurrent, of childhood, 163–65, 164t
Tobramycin, 88 cervicogenic, 147
TofranilTM. See Imipramine nonvestibular, differential diagnosis, 103t
Toluene, 323t patient history, 17, 18
Tragal stimulation testing, 29 Vestibular compensation described, 14, 15f
Transduction of sound, mechanism, 5–6, 7f Vestibular evoked myogenic potential (VEMP),
Traumatic brain injury (TBI), 152–55 34, 39
Trazadone, 153 Vestibular labyrinth
Treatment, psychiatric disorders in, 57 anatomy, function, 5–8, 6f–7f
Triamterene, 61, 127 blood supply, 5, 6f
Trichlorethylene, 341, 342 Vestibular labyrinthitis. See Vestibular neuritis
Trimethobenzamine, 61t Vestibular loss, bilateral
Trisomy syndrome, 315 diagnosis, differential diagnosis, 299, 323t
Tullio phenomenon. See Superior semicircular history, 86–87, 217, 295
canal dehiscence syndrome laboratory testing, 88–90, 89f, 219
Tumarkin’s otolithic crisis, 274, 365, 366 management, 90–91, 91t
Tympanometry, 42–43 physical examination, 87–88, 87f, 88t, 218,
295–96
Ulcerative colitis, 302t teaching points, 92–93
Undershoot dysmetria, 257 Vestibular loss, decompensated peripheral
Unilateral peripheral vestibular injury effects, bilateral, 295–98
13–16, 14f, 15f unilateral, 156–58
Usher’s syndrome, 314 Vestibular nerve, inferior, assessment, 34, 39
Utricle, 5, 6f–8f Vestibular nerve section, 268–70, 284,
285f, 287
ValiumTM. See Diazepam Vestibular neuritis
Valproic acid, 120t classification, 53, 54f
Valsalva maneuver testing, 29 diagnosis, differential diagnosis, 71–72,
Vascular cross-compression 72f, 83
syndrome, eighth cranial nerve, follow-up, 73
385–88 history, 67, 81–82, 99
Vasculitides, 302t laboratory testing, 71, 82–83, 83t
Vasculitis, 170 management, 59–62, 60t, 72–73, 84
Vasoactive amines, 162 physical examination, 67–71, 69f,
Vasodilators, 127 70f, 82, 100
Velocity storage system, 346–48 signs, symptoms, 41, 67
Venous thrombosis, 99 teaching points, 74–75, 84
Verapamil, 120t viral, 386–87, 387f
Vergence testing, 25 Vestibular neurolabyrinthitis. See Vestibular
Vertebrobasilar insufficiency neuritis
diagnosis, differential diagnosis, 241 Vestibular neuronitis. See Vestibular neuritis
drop attacks, 273–76 Vestibular reduction
history, 239–40, 240t, 244 bilateral, 49
laboratory testing, 241 unilateral, 49
management, 241–42, 242f Vestibular suppressants, 59–60, 60t
physical examination, 240–41 in acoustic neuroma management, 377
400 INDEX

Vestibular suppressants (Continued ) laboratory testing, 95, 160, 364

labyrinthine concussion, 150 management, 96–97, 160–61, 160t, 364–66
Meniere’s disease, 127 physical examination, 94–95, 160, 363
multisensory disequilibrium, 138 teaching points, 97, 161
ototoxicity management, 91 Vestibulospinal reflexes, 13
physical examination, 108 Video-oculography, 31, 32
vertigo, benign paroxysmal positional, 113 VistarilTM (Hydroxyzine), 60, 61t, 62t
Vestibuloautonomic projections, 13 Visual acuity assessment, 27
Vestibulocochlear nerve. See Cranial nerve VIII Visual–vestibular interaction testing, 36–37,
(vestibulocochlear) 170–71, 174
Vestibulo-collic reflex, 13 Vitamin B1 deficiency, 344
Vestibulo-ocular reflex (VOR) VOR. See Vestibulo-ocular reflex (VOR)
assessment, 30
as comorbidity, 328 Waardenburg’s syndrome, 314
described, 10–13, 11f–12f, 307 Wallenberg’s syndrome. See Posterior-inferior
in rehabilitation therapy, 47 cerebellar artery (PICA) syndrome
rotational testing (See Rotational testing) Weber’s test, 25
time constant, 36 Wegener’s granulomatosis, 302t
velocity storage system in, 346–48 Wernicke’s encephalopathy, 344–48, 345t,
vestibular compensation effects, 14–16, 15f 346t
Vestibulopathy, peripheral, 186 Word recognition, 41–42
Vestibulopathy of unknown cause
classification, 53, 54f Xylene, 341, 342
diagnosis, differential diagnosis, 92, 96, 160,
364, 368 ZoloftTM. See Sertraline
history, 94, 159, 363 Zolpidem, 296, 297