CONGENITAL

ANOMALIES
K.CABATANA MD

Disorders of Neuralation
(1-4 w gestation)

 During pregnancy, the human brain and spine

begin as a flat plate of cells, which rolls into a
tube, called the neural tube.
If all or part of the neural tube fails to close,
leaving an opening, this is known as an open
neural tube defect, or ONTD.
This opening may be left exposed (80 percent
of the time), or covered with bone or skin (20
percent of the time).

Disorders of closure of Neural tubes

1- Anencephaly
2- Neural tube defect (spinal defect)
3- encephalocele


Open Neural Tube Defects
ETIOLOGY:

ONTDs 95%
ONTDs result from a combination of genes
inherited from both parents, coupled with
environmental factors.
For this reason, ONTDs are considered
multifactorial traits, meaning "many factors,"
both genetic and environmental, contribute to
their occurrence

 Folic acid deficiency:

Drugs antagonizing folic acid:
Valproic acid, CBZ, phenytoin, phenoba., alcohol,
thalidomide, irradiation, maternal diabetes
Syndromal disorders: trisomy 18, 13,
Malnutrition zinc , folate def.

TYPES OF ONTDs
PRIMARY
-95% of all NTD

Primary failure of closure/disruption of NT btw

18-28 days.
Eg. -Myelomeningocele
Encephalocele
Anencephaly

TYPES OF NTD
SECONDARY
-5% of all NTD.

Abnormal development of lower sacral

segment during secondary neuralization
Skin is usually intact
Involves lumbo-sacral region
Eg. Spina Bifida Occulta
Meningocele

ABNORMAL DEVELOPMENT

MALFORMATIONS RESULTING FROM

ABNORMALITIES IN GROWTH AND MIGRATION
WITH INCOMPLETE DEVELOPMENT OF THE BRAIN

Heterotopias

GENETICALLY LINKED MIGRATION DISORDERS

ENVIRONMENTALLY INDUCED MIGRATION

DISORDER: FETAL ALCOHOL SYNDROME

FETAL ALCOHOL
SYNDROME

one of the more common nongenetic causes of

mental retardation

pregnant women to avoid all alcohol, especially

during the first trimester

pre- and postnatal growth retardation occurs along

with cardiovascular, limb, and craniofacial
abnormalities

MALFORMATIONS RESULTING FROM

CHROMOSOMAL TRISOMY AND
TRANSLOCATION

translocation syndromes like trisomy 21

moderately mentally retarded and of short stature

hypoplastic facies with short noses, small ears with

prominent antihelices, and prominent epicanthal
folds

MALFORMATIONS RESULTING FROM

DEFECTIVE FUSION OF DORSAL
STRUCTURES

Spinal Bifida

Cranial Bifida

Arnold-Chiari Malformation

Spinal Bifida

arches and dorsal spines of the vertebrae are

absent

spinal cord, however, may be malformed either at

one level or at many levels

meningomyelocele

meningocele.

Spina bifida

Spina Bifida Occulta

Very mild & common form.
Level - L5 & S1.
Asymptomatic which can only
d e t e c t e d b y x - r a y o r
investigating a back injury.
May be assoc iated with
tethered cord/ recurrent
meningitis ( dermal sinus )
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 Usually associated with skin

visible signs on the back.
Dimple
Dermal Sinus
lipoma / Pad of subcutaneous
fat
small hair growth
Nevus flaminous (red spot) or
port wine

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Dimple

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Tuft of hair

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Dimple with nauves port wine

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Meningocele
Least common form
Sac contains meninges and
cerebro-spinal fluid. And
covered with skin
Cerebro-spinal fluid protects
the brain and spinal cord.
The nerves are not badly
d a m a g e d a n d a b l e t o
function normally.
Small sac which increases on
crying
Limited disability is present.

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Meningocele
Investigation:-
MRI HEAD exclude hydrocephalus/
dysgenesis
MRI SPINE exclude
(i)Diastematomyelia division of spinal
cord into two halves by projection of
fibrocartilagenous or bony septum from
post vertebral body
(ii) Tethered cord slender threadlike
filum terminale attached to coccyx conus
here is below L2 instead L 1
Treatment
Skin intact surgery in infancy
Skin lacerated urgent treatment
Look for recto vaginal fistula

Tethered cord
The spinal cord could be
caught against the vertebrae
Normal cord ends at lower end
of L 1
Motor weakness of lower
limbs
Sphincteric problems such as
inefficient bladder control.
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Autopsy of Infant with tethered cord

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Myelomeningocele
Most serious and common
The cyst not only contains
meninges and CSF but also the
nerves and spinal cord.
The spinal cord is damaged or not
properly developed resulting in
motor and sensory deficit.
Majority have bowel and bladder
problems.

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 Myelomeningocele, is the most severe and occurs when the

spinal cord is exposed through the opening in the spine,
resulting in partial or complete paralysis. and may have
urinary and bowel dysfunction.

Meningomyelocele
Sac + CSF + neural
element + discontinuous
skin +
hydrocephalus(80%).
TYPE 94% of all NTD Lumbo sacral
- Area of well developed
skin at periphery With thin
apex covered by glistening
arachnoid membrane
- Usually CSF oozing +

Myelomeningocele

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Intact Mylomeningocele

Thin transparent membrane

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Intact Mylomeningocele
covered by thin membrane
surrounded by hyper pigmentation

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ARNOLD CHIARI SY ARNOLD CHIARI

SYNDROME NDROAME

ARNOLD CHIARI
SYNDROME

Cephalocele

Skull-base or calvarial defect that is associated

with herniation of intracranial contents

Meningo-encephalocele- herniated contents

contain both meninges and brain tissue

Meningocele- herniated contents contain

meninges only

Pathologenesis

Skull-base cephaloceles-represent defects of

endochondral bone; caused either by failure of
induction of bone due to faulty neural tube closure
or disunion of basilar ossification centers

Calvarial cephaloceles-represent defects of

membranous bone;caused either by a defect of
bone induction, mass effect and pressure erosion
of bone by an expanding intracranial lesion, or
failure of neural tube closure

CLASSIFICATION BASED
ON LOCATION

Occipital

Frontoethmoidal

Parietal
Nasopharyngeal.

Occipital Cephaloceles

Most common location for the development of a

cephalocele

Associated with a less favorable prognosis

Supratentorial and infratentorial structures

herniates with equal frequency

Poor prognostic indicators include hydrocephalus,

microcephaly, and the presence of brain tissue in
the herniated sac

Frontoethmoidal
Cephaloceles

Failure in the normal regression of a projection of

dura that extends from the cranial cavity to the skin
through a persistent foramen cecum or fonticulus
frontalis.

Persistence of this projection of dura -give rise to a

dermal sinus tract- give origin to a dermoid or
epidermoid tumor

Examination reveals a superficial skin-covered

mass or nasal dimple and frequently hypertelorism

SUBTYPES

Frontal and nasal bones (frontonasal cephalocele)

Frontal, nasal, and ethmoidal bones

(frontoethmoidal cephalocele)

frontal, lacrimal, and ethmoidal bones extending

into the anteromedial portion of the orbit (nasoorbital cephalocele)

Parietal cephaloceles

Uncommon

Prognosis is generally poor -common association

with major brain anomalies

Common location for Atretic cephaloceles

Nasopharyngeal
Cephaloceles

Uncommon

Occult

Lesions usually do not present until the end of the

first decade of life

Diagnosed during an evaluation for persistent nasal

stuffness or excessive mouth breathing.

Result in both endocrine and visual dysfunction

Arnold-Chiari Malformation

elongation and displacement of the brain stem and

a portion of the cerebellum through the foramen
magnum

Hydrocephalus, spina bifida with meningocele, or

meningomyelocele associated conditions

MALFORMATIONS CHARACTERIZED BY EXCESSIVE

GROWTH OF ECTODERMAL AND MESODERMAL TISSUE
AFFECTING SKIN, NERVOUS SYSTEM, AND OTHER TISSUES

Intracranial Lipomas

Dermal Sinuses

Arachnoid cysts

Intracranial Lipomas

Normal development, an undifferentiated

mesenchyme that surrounds the developing brain
gives - leptomeninges and the subarachnoid space

Abnormal differentiation - undifferentiated

mesenchyme may lead to the formation and
deposition of fat in the subarachnoid space

Lipomas typically contain blood vessels and cranial

nerves, creating an obstacle to their surgical
removal

COMMON LOCATIONS

Deep interhemispheric fissure

Quadrigeminal plate cistern

Interpeduncular cistern

Cerebellopontine angle cistern

Sylvian cistern

Dermal sinuses

3rd-5th weeks of intrauterine life -defect occurs in the

separation of neuroectoderm (the embryological
precursor of nervous tissue) from surface ectoderm (the
embryological precursor of skin

Abnormal communication between the dermis and the

intracranial cavity

Composed of stratified squamous epithelium (epidermal

component) as well as hair follicles, sebaceous glands,
and sweat glands (dermal component).

Clinical presentation

Benign cutaneous cosmetic blemish

Serious intracranial infection
Tumorlike process due to mass effect from a
dermoid or epidermoid cyst.

Arachnoid Cysts

CSF-containing lesions covered by membranes

that consist of arachnoid cells and collagen fibers

Result from an anomalous splitting and duplication

of the endomeninx

2/3RDS - located in the supratentorial space, most

commonly the sylvian cistern; 1/3RD - located in
the infratentorial space

Clinical manifestations

Intracranial hypertension

Obstructive hydrocephalus

Headache

Seizure

Neurologic deficit

MALFORMATIONS RESULTING FROM

ABNORMALITIES IN THE VENTRICULAR
SYSTEM

Syringomyelia

Syringobulbia

Hydrocephalus

Factors Associated With Increased

Risk of NTDs. . .
Family history of NTD
A previous pregnancy affected with NTD
Maternal insulin-dependent diabetes
Maternal obesity
Anti-epileptic drugs (Valporic Acid, Carbamazapine)
Lower socioeconomic/educational level, dietry deficiency
specially folic acid
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 The only most significant risk factor

associated with NTDs is folic acid
deficiency

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Folic Acid For Women

As NTD occur before diagnosis of
pregnancy.
All women of childbearing age
should receive 400 micrograms
(0.4 mg) of folic acid daily.
Women who have had a previous
child with NTD should receive 4000
micrograms (4 mg) of folic acid
daily. 2 months before pregnancy
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Neural tube defects prevention

Folic acid deficiency:
If previous history of NTD in family :
4mg 1 2 month before pregnancy To 3 months
thereafter
Else for every other women of child bearing age :
0.4mg 1 month before conception till 12 weeks
gestation.

THANK YOU