Medial Temporal Lobe

Anatomy
Eric K. van Staalduinen, DOa, Michael M. Zeineh, MD, PhDb,*

KEYWORDS

Medial temporal lobe anatomy
Mesial temporal lobe
Hippocampal formation
Hippocampus

Cornu ammonis
CA fields
Dentate gyrus

KEY POINTS

Knowledge of normal hippocampal anatomy and development improves recognition of hippocam-
pal pathology.

Deciphering hippocampal subfield anatomy on routine clinical imaging is now possible, with greater
confidence owing to improved imaging techniques and higher field strength MR scanners.

INTRODUCTION HIPPOCAMPAL TERMINOLOGY AND

DEVELOPMENT
The medial temporal lobe (MTL) is a complex
anatomic region in the ventromedial aspect of The classic gross appearance of the human hippo-
the temporal lobe. It consists of the hippocampal campal formation is that of a prominent, bulging
formation, the parahippocampal region, and the eminence in the floor of the temporal horn of the
amygdaloid complex and plays a key role in lateral ventricle (Fig. 1).2 The term “hippocampus”
numerous cognitive processes, including the crea- (or sea horse) was first used by the Italian anato-
tion, retrieval, and consolidation of new memories, mist and surgeon Giulio Cesare Aranzio (Arantius)
spatial navigation, emotion, and social behavior.1,2 in 1587, although it is unclear which aspect of the
Although much work has been done to elucidate hippocampus reminded him of a sea horse, as he
the complex anatomic relationships, cytoarchitec- also likened the hippocampus to a silkworm.2
ture, and functional connectivity within the MTL, Centuries later, Winslow (1732) likened the
the authors’ goal is to create an anatomic refer- appearance to a ram’s horn, and de Garengoet
ence for clinicians and scientists that highlights (1742) named the hippocampus “Ammon’s horn”
and summarizes this region, with special attention after the Egyptian deity Amun, who has the head
to MR imaging. They have therefore focused pri- of a ram.3 Lorente de Nó (1934) appropriated the
marily on the hippocampal formation, discussing term “Cornu Ammonis” (CA) for the hippocampus
its gross structural features and anatomic relation- proper, a term that remains synonymous with the
ships, relevant subfield anatomy, and hippocam- hippocampus today.4
pal connectivity. They detail how this complex Although much of the cerebral cortex consists of
anatomy appears on MR imaging and also discuss a 6-cell-layer neocortex, the mesial temporal
hippocampal terminology and development, structures are formed of more primitive allocortex
normal anatomic variants, clinically relevant dis- (which consists of 3, 4, or 5 cell layers), which be-
ease processes, and automated segmentation gins in early fetal life as a flat cortical plate along
software common to hippocampal analysis. Ta-
neuroimaging.theclinics.com

the medial wall and floor of the temporal horn.5 Un-

ble 1 lists important anatomic terms in this review. equal growth and thickening of the dentate gyrus

a
Department of Radiology, Stanford University, 453 Quarry Road, Stanford, CA 94304, USA; b Department of
Radiology, Stanford University, 1201 Welch Road, Room P271, Stanford, CA 94305, USA
* Corresponding author.
E-mail address: mzeineh@stanford.edu

Neuroimag Clin N Am 32 (2022) 475–489

https://doi.org/10.1016/j.nic.2022.04.012
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476 van Staalduinen & Zeineh

Table 1
Anatomic terms

Ambient gyrus The most prominent bulge in the medial temporal lobe; composed
of entorhinal cortex and categorized as medial extension of
parahippocampal gyrus; part of the anterior uncus
Band of Giacomini The most superficial part of the dentate gyrus in the hippocampal
head, present along the inferior and medial uncal surfaces;
continues caudally in the hippocampal body as the margo
denticulatus
Collateral sulcus Runs in an anteroposterior course along the inferior temporal and
occipital lobes; anteriorly separates the parahippocampal gyrus
medially from the fusiform (or lateral occipitotemporal) gyrus
laterally; posteriorly separates the lingual gyrus medially from
the lateral occipitotemporal gyrus laterally
Endorhinal sulcus Separates the anterior perforated substance from the uncus; used
as a landmark to identify the piriform cortex; seen on coronal MR
at the level of the limen insulae
Fasciola cinerea The superficial continuation of the margo denticulatus along the
hippocampal tail; situated between the gyrus fasciolaris and the
gyrus Andreas Retzius
Gyrus of Andreas Retzius The superficial continuation of the CA1 field along the
hippocampal tail; demonstrates characteristic small, rounded
bulges on its surface
Gyrus fasciolaris The superficial continuation of the CA3 field along the
hippocampal tail; covered by alveus
Gyrus intralimbicus Also known as the uncal apex; is a small, rounded medial protrusion
posterior to the band of Giacomini in the posterior uncus; is
composed of CA4 and CA3; and is covered by alveus; fimbria
attaches to its caudal extremity; demarcates the caudal aspect of
the hippocampal head
Intrarhinal sulcus Shallow sulcus within the entorhinal cortex
Limen insulae Also known as the frontotemporal junction, formed at the junction
between the frontal and temporal lobes; forms the lateral limit of
the anterior perforated substance and represents the level at
which the middle cerebral artery bifurcates; marks the reference
level for the piriform cortex, amygdala, and entorhinal cortex
Margo denticulatus The most superficial part of the dentate gyrus along the
hippocampal body
Piriform lobe Consists of cortical amygdala, anterior segment of uncus, and
anterior parahippocampal gyrus
Rhinal sulcus Rostral continuation of the collateral sulcus; separates the temporal
pole from the parahippocampal gyrus
Semiannular sulcus Also known as sulcus semiannularis; along the medial surface of the
anterior uncus; separates the semilunar gyrus (amygdala) above
from the ambient gyrus (parahippocampal gyrus) below
Semilunar gyrus Covers the corticomedial nuclei of the amygdala in the anterior
uncus
Superficial hippocampal Present along the inferior border of the hippocampal body,
sulcus separating the margo denticulatus from the subiculum
Uncal sulcus Along the medial surface of the posterior uncus, separates the
hippocampus above from the parahippocampal gyrus below
Uncinate gyrus Forms part of the posterior uncus; is continuous rostrally with the
ambient gyrus; composed of CA1 and subiculum

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 Medial Temporal Lobe Anatomy 477

subicular complex, and some include the entorhi-

nal cortex as part of the formation. Although the
term “hippocampus” consists of the dentate gyrus
and CA fields in an anatomic sense of the word,
some definitions have also included the subicular
complex, as the subiculum is not easily distin-
guished from the CA fields on MR images.

Hippocampus
The hippocampus is an arched bilaminar gray and
white matter structure located in the MTL that
demonstrates an enlarged anterior extremity and
a posterior extremity that narrows as a comma
(see Fig. 1; Fig. 3).7 It has a length of approxi-
mately 4.5 cm along the rostrocaudal axis2 and
is commonly divided into 3 parts: (1) an anterior
part or head; (2) a middle part or body; (3) a poste-
rior part or tail. The CA fields and dentate gyrus are
gray matter structures that form 2 interlocking
U-shaped laminae, which are partially separated
by the vestigial hippocampal sulcus (Fig. 4).7 The
alveus and fimbria are white matter structures
that together constitute the fornix. Several fissures
surround the hippocampus, including the lateral
Fig. 1. Intraventricular aspect of the hippocampus, extension of the ambient cistern, termed the trans-
viewed from above. The temporal horn has been
verse fissure of Bichat, which separates the thal-
opened and choroid plexus removed. 1, hippocampal
body; 2, hippocampal head and internal digitations;
amus above from the parahippocampal gyrus
3, hippocampal tail; 4, fimbria; 5, crus of fornix; 6, sub- below (see Fig. 14). The superolateral extension
iculum; 7, splenium of corpus callosum; 8, calcar avis; of the transverse fissure is the choroidal fissure,
9, collateral trigone; 10, collateral eminence; 11, uncal whereas the inferolateral extension is the hippo-
recess of the temporal horn. (From Duvernoy HM. The campal fissure, which is often obliterated but sep-
Human Hippocampus: Functional Anatomy, Vasculari- arates the dentate gyrus from the subiculum and
zation and Serial Sections with MRI. Springer Berlin CA fields. In general, the gray matter structures
Heidelberg; 2005.) of the hippocampus appear as other gray matter
structures on MR imaging, with signal intensity
matching that of cortex and deep gray nuclei else-
initiates the process of hippocampal infolding,
where throughout the brain, except for the stratum
whereby the hippocampal sulcus deepens and
lacunosum moleculare, which contains myelinated
shifts from a location between the dentate gyrus
white matter of the perforant pathway.
and cornu ammonis to a location between the den-
Although a comprehensive discussion of inter-
tate gyrus and subiculum (Fig. 2); this results in the
nal hippocampal architecture is beyond the scope
characteristic interlocking C-shape configuration
of this chapter, a concise review is provided for
of the adult hippocampus, with the external sur-
completeness. The hippocampus proper consists
faces of the dentate gyrus and CA1/subiculum in
of 6 layers, from the ventricular cavity to the vesti-
contact around a diminutive hippocampal sulcus.6
gial hippocampal sulcus: alveus (1, see Fig. 4),
stratum oriens (2), stratum pyramidale (3), stratum
SURFACE AND SUBFIELD ANATOMY OF THE radiatum (4), stratum lacunosum (5), and stratum
MEDIAL TEMPORAL LOBE moleculare (6). As allocortex typically shows only
3 layers, the 6 layers of the CA listed above are
The term “hippocampal formation” refers to a grouped into 3 layers: stratum oriens (2), stratum
collection of cytoarchitectonically distinct compo- pyramidale (3), and the molecular zone (4–6, a
nents that are linked by predominantly unidirec- layer that combines the strata radiatum, lacuno-
tional internal connections and organized as a sum, and moleculare, commonly termed the
functional unit. These components consist of the SRLM).4,7 Along the other side of the hippocampal
dentate gyrus (or gyrus dentatus/DG), hippocam- sulcus is the dentate gyrus, a trilaminate cortical
pus proper (or cornu ammonis/CA fields), region consisting of a molecular layer (8), a

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478 van Staalduinen & Zeineh

Fig. 2. Coronal plane illustration of hippocampal infolding stages. D, dentate gyrus; C, cornu ammonis; S, subic-
ulum; P, parahippocampal gyrus; T, temporal horn. Large arrow in (A) and small arrows in (B) and (C), hippocam-
pal sulcus. (From Kier EL, Kim JH, Fulbright RK, Bronen RA. Embryology of the Human Fetal Hippocampus: MR
Imaging, Anatomy, and Histology. AJNR Am J Neuroradiol. 1997;18:525-532.)

granular layer (9), and a polymorphic layer genu of the CA, where it enters the concavity of
(arrowhead).8,9 the dentate gyrus. The CA4 field is classically
Lorente de Nó (1934) described 4 distinct hippo- described as those pyramidal cells that are situ-
campal fields based on cytoarchitectural analysis, ated within the concavity of the dentate gyrus,
termed CA1–4 (see Fig. 4).2,4 The CA1 field bor- enclosed by the granule cell layer. Some suggest
ders the subiculum medially and continues along grouping the CA3 and CA4 fields together, as there
the inferior aspect of the hippocampus laterally, is no cytoarchitectonic or connectional reason to
curving upward along the temporal horn of the distinguish CA4 from CA3,2 with commonality pre-
lateral ventricle; this coincides with an expanded sent of the incoming mossy fibers and colocaliza-
pyramidal cell layer, and the CA1/CA2 border is tion of the outgoing endfolial pathway joining the
denoted by a marked transition to the dense, nar- Schaffer collaterals. Yet, there is not a laminate
row pyramidal cell layer of CA2.2 The CA2/3 structure to CA4.8 The CA1 field has a specific
border roughly corresponds to an expansion of sensitivity to anoxia and has thus been termed
the CA3 pyramidal layer. The CA3 field is thought the vulnerable sector (or Sommer sector), whereas
to correspond to the superomedial curve, or CA3 is known as the resistant sector (or

Fig. 3. (A) Axial and (B) sagittal fGATIR 3T images. The hippocampal head (H) is located anterior to the plane of
the interpeduncular cistern, whereas the tail (T) is posterior to the midbrain (M) and the body (B) is in between.
The amygdala (A) is separated from the hippocampal head by the uncal recess of the temporal horn (Un). Fimbria
(f), uncal apex (yellow arrow).

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 Medial Temporal Lobe Anatomy 479

Fig. 4. (A) Magnetic resonance microscopy (MRM) of the hippocampal body coronally at 9.4 T. (B) Nissl stain spec-
imen corresponding to A. From lateral to medial, the MRM displays the following: 1, alveus; 2, stratum oriens
(between 1 and 3); 3, stratum pyramidale; 4, stratum radiatum; 5, stratum lacunosum; 6, stratum moleculare;
7, hippocampal sulcus; 8, stratum moleculare; 9, dentate granule cell layer (straight arrow in B); and 10, polymor-
phic layer (arrowhead in B). Also seen are cornu ammonis, CA1 to CA4, caudate nucleus tail (CN), subiculum (Sub),
and the lamellar retinotopic organization of the lateral geniculate body (curved arrow). (From Fatterpekar GM,
Naidich TP, Delman BN, et al. Cytoarchitecture of the Human Cerebral Cortex: MR Microscopy of Excised Speci-
mens at 9.4 Tesla. AJNR Am J Neuroradiol. 2002;23:1313-1321.)

Spielmeyer sector).7 CA2 is thought to be involved architecture, with the slightly hyperintense hilus
with Lewy body disease.10 (including the dentate gyrus and CA4) present cen-
MR imaging of these strata and subfields has trally; CA3, CA2, and CA1 wrapping around the
been challenging before the advent of high-field, hypointense SRLM; the hippocampal sulcus and
high-resolution MR imaging, with prior studies SRLM separating the remainder of CA1 from the
showing that these structures cannot be precisely DG; and contiguity with the subicular complex.
or reliably predicted as macroscopic, anatomic Notably, the subicular complex often shows
landmarks.11 However, more recent studies using some hypointensity, likely related to multiple
higher field strengths (3T) and improved imaging myelinated perforant pathway bundles that
techniques suggest that some of these boundaries shorten T2 relaxation.
and strata can be visualized in vivo with
reproducibility.9,12–14 Hippocampal head The hippocampal head (Fig. 7;
The authors now review the hippocampal head, see Fig. 11F, G) represents the anterior compo-
body, and tail with greater detail, emphasizing the nent of the hippocampal arc. It features 2 to 4 in-
structural anatomy that can be readily appreciated ternal digitations consisting of transverse folds of
on MR imaging, beginning with the body, where CA around a central extension of the DG.7 The
the laminate architecture is more tractable. Intra- DG is present more posteriorly within the hippo-
ventricular components refer to visibility along campal head, whereas CA fields and subiculum
the floor of the temporal horn of the lateral ventricle predominate more anteriorly. The extraventricular
during dissection, whereas extraventricular (or part of the hippocampal head forms the posterior
cisternal) parts refer to visibility along the surface segment of the uncus, with the uncinate gyrus
of the ambient cistern. and uncal apex (also known as the gyrus intralim-
bicus) representing prominent bulges in the MTL at
Hippocampal body the mid- and caudal aspects. The uncinate gyrus is
The intraventricular hippocampal body (see Figs. continuous with the ambient gyrus rostrally and
1 and 3) is an element in the floor of the temporal has been described as a strip of CA1 and subicu-
horn of the lateral ventricle that is hidden by lum,5 whereas the uncal apex is present as a small
choroid plexus and has ependyma covering the round protuberance medial to the usual profile of
protruding alveus. Its medial border is defined by the hippocampus, is composed of CA4 and CA3
the fimbria, whereas the lateral border consists fields, and is firmly attached to the fimbria at its ex-
of the collateral eminence (which is the intraven- tremity; this is an important anatomic landmark for
tricular protrusion of cortex covering the collateral MR imaging, as it is used to demarcate the poste-
sulcus).7 The extraventricular part is visible medi- rior margin of the hippocampal head and approxi-
ally (Fig. 5). mate the caudal limits of the entorhinal and
On coronal MR images (Fig. 6; see Fig. 11), the perirhinal cortices.14 A useful method for confi-
hippocampal body has the traditional C within a C dently identifying the uncal apex/GIL is to look

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480 van Staalduinen & Zeineh

Fig. 5. Schematic (A)/specimen (B) images of the hippocampal body/tail. The most superficial part of the dentate
(1 and 7) along the hippocampal body is termed margo denticulatus (2). Rounded surface protrusions termed
dentes represent a superficial manifestation of dentate gyrus folding (2). White matter fibers from the alveus
(5 and 12) continue caudally along the superomedial surface as fimbria (4 and 13). The fimbriodentate sulcus
(3) separates the margo denticulatus from the fimbria, whereas the superficial hippocampal sulcus (arrows) sep-
arates the margo denticulatus from the subjacent subiculum (6 and 14).5 As the body transitions to tail, the
fimbria (4 and 13) begins to separate from the margo denticulatus (2) as it ascends to join the crus of the fornix
(130 ). Concomitant widening of the fimbriodentate sulcus (3) exposes the superficial continuation of CA3 covered
by alveus, termed gyrus fasciolaris (10). The CA1 field appears progressively at the surface, often producing small,
rounded bulges, termed the gyri of Andreas Retzius (8). As the margo denticulatus continues caudally, it becomes
smooth and narrow, forming the fasciola cinerea (9).5 The terminal segment covers the subsplenial surface, thus
termed subsplenial gyrus (15). Although controversial, it is favored to consist of CA without dentate gyrus, with
CA3 along the medial edge and CA1 constituting its majority.5 The subiculum (14) is continuous caudally as the
isthmus of the cingulate cortex (16). The sulcus dentatofasciolaris (11), splenium of the corpus callosum (18), and
subcallosal trigone (17) are labeled for completeness. (From Duvernoy HM. The Human Hippocampus: Functional
Anatomy, Vascularization and Serial Sections with MRI. Springer Berlin Heidelberg; 2005.)

for the fimbria, as it can often be seen attaching to On coronal MR images (Fig. 8), the tail seems to
its caudal extremity (see Figs. 3, 7D, 9, 11G). widen because of its superomedial curvature (see
Although the anterior part of the uncus is also visu- Figs. 1 and 3, posteriorly), and the division be-
alized at the level of the hippocampal head, it is tween body and tail often coincides with the
important to note that the ambient gyrus (see appearance of the wing of the ambient cistern.
Figs. 7B and 11E), the most prominent bulge in Typical hippocampal architecture is observed,
the MTL, is actually entorhinal cortex, which is with CA fields surrounding the SRLM and central
categorized as medial extension of the parahippo- dentate gyrus.
campal gyrus.15 A few practical points are highlighted before
continuing the discussion later. First, the structure
Hippocampal tail The hippocampal tail represents of the hippocampus is the same throughout its
the posterior part of the hippocampal arc. It also different segments, consisting of the U-shaped
appears as a transverse bulge in the floor of the dentate gyrus and surrounding CA. Second, the
lateral ventricle without surface digitations. The in- segment of dentate gyrus visible from within the
ternal architecture is composed of CA, centered ventricle and along its medial surface is known
by digital extensions of DG, with CA fields extend- by 3 terms depending on location: the band of Gia-
ing beyond the DG in the caudal-most aspect, as comini in the head/uncus, margo denticulatus in
in the head. The intraventricular part is thickly the body, and fasciola cinerea in the tail.
covered by alveus and subependymal veins,
whereas its medial border is flanked by fimbria, Parahippocampal region
and its lateral border is the collateral trigone.7 The parahippocampal gyrus forms the medial
The extraventricular part demonstrates continua- edge of the brain, extending from the rhinal sulcus
tion of the hippocampal formation, with similar sur- (6, Fig. 9) anteriorly to the splenium posteriorly.16 It
face features (see Fig. 5). encompasses the perirhinal, entorhinal, and

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 Medial Temporal Lobe Anatomy 481

Fig. 6. (A) Large and (B) small field-of-view coronal 3T of the hippocampal body. (A) Regional anatomy: hippo-
campal body (HB), parahippocampal gyrus (PHG), fusiform gyrus (FG), inferior temporal gyrus (ITG), middle tem-
poral gyrus (MTG), superior temporal gyrus (STG), collateral sulcus (cs), and occipitotemporal sulcus (ots). (B)
Hippocampal subfield anatomy: CA1–4, hilus (CA4/DG), subiculum (Sub), SRLM (stratum radiatum, lacunosum,
and moleculare; red arrows), angular bundle (Ab), alveus (a), and fimbria (f).

parahippocampal cortices and subiculum along its inferiorly, and continues caudally to join the
rostrocaudal extent and is continuous along its isthmus of the cingulate gyrus below the splenium
longitudinal axis, although it can be divided into of the corpus callosum (see Fig. 9).
anterior and posterior segments. The anterior The subiculum (or “bed” of the hippocampus) is
segment, also known as the piriform lobe, consists a trilaminate cortex composed of a superficial mo-
of the uncus and the entorhinal area, whereas the lecular layer, a central pyramidal cell layer, and a
posterior segment is separated from the hippo- deep polymorphic layer. It borders the CA1 field
campus by the uncal sulcus, consists of subiculum of the hippocampus and is subdivided into several
superomedially and parahippocampal cortex segments, from lateral to medial: prosubiculum

Fig. 7. The hippocampal head at 3T, with a sagittal cross-reference image (A) and zoomed-in coronal images at
the rostral, mid, and caudal aspects (B–D). The hippocampal head is widened owing to anteromedial wrapping
(as seen in Figs. 1 and 3, anteriorly) and demonstrates an undulated appearance due to interdigitations (images B
and C, white arrows). Approximate boundaries of CA1–4, subiculum (Sub), amygdala (A), semilunar gyrus (SLG),
ambient gyrus (AG), sulcus semiannularis (ssa), SRLM (stratum radiatum, lacunosum, and moleculare; red arrows),
uncinate gyrus (UG), gyrus intralimbicus (GIL), fimbria (f), alveus (a).

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482 van Staalduinen & Zeineh

the perforant pathway8 and thus has lower signal

on T2-weighted fast spin-echo MR images (see
Fig. 6).
The entorhinal cortex (Figs. 10 and 11) is
composed of periallocortex that is obliquely ori-
ented and contiguous with the parasubiculum. It
is the most rostrally situated component of the
hippocampal formation, with its rostral extreme
identified just behind the limen insulae and its
caudal-most portion defined as one slice caudal
to the gyrus intralimbicus on coronal MR images.19
Its medial portion forms the ambient gyrus,
extending to the sulcus semiannularis (small ar-
row, see Fig. 10).15 Its lateral border extends to
Fig. 8. Coronal T2W-FSE MR image of the hippocam- the medial bank of the collateral sulcus, where it
pal tail at 7T. Surface anatomy on the radiologic right: borders the perirhinal cortex.19 It demonstrates a
gyrus fasciolaris (GF), fasciola cinerea (FC), gyrus of 6-layer pattern, with characteristic islands of large
Andreas Retzius (GAR), subsplenial gyrus (SSG). Sub- pyramidal cells in layer II (see Fig. 10). Macroscop-
field anatomy on the left: CA1-4, SRLM (stratum radi- ically, this shows small, raised mounds on the sur-
atum, lacunosum, and moleculare, red arrow), face termed “verrucae hippocampi.”2 Despite its
subiculum (Sub). Splenium (S), corpus callosum (CC), small size, it is the principal input to the hippocam-
crus of the fornix (F). pus, with the origin of the perforant/alvear path-
ways arising from its layer II/III neurons.7 In
addition, it is one of the hallmark locations of tau
(continuous with CA1 but not universally agreed on deposition and neurodegeneration in Alzheimer
as a separate region), subiculum, presubiculum, disease (AD), closely following transentorhinal/
and parasubiculum.17,18 The parasubiculum perirhinal tau.20
passes around the medial margin of the parahip- The white matter of the parahippocampal gyrus
pocampal gyrus and is contiguous with the ento- situated deep to the subicular complex is called
rhinal area. The subiculum contains the angular bundle. Within this region, fibers of
anteroposterior projecting myelinated fibers from the perforant path system travel to caudal levels

Fig. 9. Sagittal dissection of the right hemisphere. Surface anatomy demonstrates the parahippocampal gyrus
(110 and 11), semilunar gyrus (14), ambient gyrus (13), entorhinal area with islands (12), isthmus of the cingulate
cortex (10), rhinal sulcus (6), uncal sulcus (red arrow), uncinate gyrus (24), band of Giacomini (23), uncal apex (22),
fimbria (21), fornix (27), subcallosal gyrus (7) and sulcus (1), paraterminal gyrus (160 ), anterior commissure (26),
corpus callosum (28), dentate gyrus (18), anterior calcarine sulcus (4), collateral sulcus (5). (Adapted from Duver-
noy HM. The Human Hippocampus: Functional Anatomy, Vascularization and Serial Sections with MRI. Springer
Berlin Heidelberg; 2005.)

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 Medial Temporal Lobe Anatomy 483

Fig. 10. Coronal, thionin-stained section of the human hippocampus and entorhinal cortex (EC). The numbers at
the top right of the image indicate the layers of the EC. Note the shallow intrarhinal sulcus (irs) located in the EC.
Amygdala (A), subiculum (S), temporal horn of the lateral ventricle (V), and perirhinal cortex (PRC). An asterisk
marks the collateral sulcus, whereas small arrows demarcate the dorsomedial and ventrolateral extents of EC
layer II. (From Insausti R, Amaral DG. Hippocampal Formation. In: The Human Nervous System. Elsevier;
2012:896-942.)

of the hippocampal formation, perforate through predominantly forward loop of excitatory connec-
the subiculum and hippocampus, and terminate tions and inhibitory neurons between the entorhi-
in CA1 and the outer two-thirds of the molecular nal cortex and the rest of the hippocampal
layer of the dentate gyrus.2,8 It is well defined formation. A detailed discussion of hippocampal
and partially myelinated at birth. circuitry is beyond the scope of this chapter; how-
ever, a comprehensive schematic is provided in
Amygdaloid complex Fig. 12.
The amygdala is an almond-shaped, gray matter Subcortical output from the hippocampal for-
structure consisting of many nuclei (see Fig. 11). mation largely originates in the CA3 field and sub-
Its rostral portion approximates that of the entorhi- iculum and extends into the alveus and fimbria to
nal cortex (where it can be identified by the limen the fornix. A smaller precommissural projection,
insula), and it is bounded medially by the piriform arising mainly from the cells of the hippocampus
and periamygdaloid cortices, together termed proper, extends to the septal region, primarily
the piriform cortex-cortical amygdaloid (PCA) re- innervating the lateral septal nucleus, whereas a
gion.21 Except at its rostral-most level, the amyg- much larger postcommissural bundle, arising pri-
dala reaches the medial surface of the temporal marily from the subicular complex, provides input
lobe throughout its rostrocaudal extent, forming to the mammillary bodies. Impulses then reach
the semilunar gyrus.22 Three main regions consti- the anterior thalamic nucleus, either directly or
tute the amygdala body, including a group of via the mammillary bodies from the mammillotha-
deep nuclei called the basolateral nuclear group, lamic tract, before finally reaching the posterior
a superficial laminated region in the anterior part cingulate, retrosplenial, and anterior cingulate
of the uncus termed the corticomedial group, cortices.7
and a central group.22 The corticomedial nuclei
are olfactory centers, whereas the basolateral
and central nuclei have limbic functions.7 The Hippocampal Vascularization
amygdala is separated from the hippocampus by
The hippocampus is supplied by the anterior, mid-
the anterior aspect of the temporal horn (see
dle, and posterior hippocampal arteries, which are
Fig. 3B), and a well-defined hippocampal-amyg-
variably derived from the posterior cerebral artery
daloid transitional area, which is approximately
and its branches as well as the anterior choroidal
coincident with the choroidal fissure.23
artery. The hippocampal head and uncus are sup-
plied by the anterior hippocampal artery, whereas
Hippocampal Connectivity
the body and tail are vascularized by the middle
Hippocampal connectivity consists of many and posterior hippocampal arteries (Fig. 13). The
intrinsic and extrinsic pathways, with a anterior hippocampal artery courses through the

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484 van Staalduinen & Zeineh

Fig. 11. Coronal T1W 3T MR images of the anteromedial temporal lobe (A–H, rostral to caudal). Anatomic land-
marks used to identify the hippocampal formation, parahippocampal region, and amygdaloid complex are delin-
eated. (A) The lateral edge of the temporopolar sulcus (tps) demarcates the dorsal limit of the temporopolar
cortex (TPC), whereas the medial edge of the inferotemporal sulcus (its) delineates its ventrolateral extent. (B)
The limen insulae (LI), also known as the frontotemporal junction, approximates the rostral extremes of the piri-
form cortex-cortical amygdaloid region (PCA) and the perirhinal cortex (PRC). At this level, the PCA extends from
the fundus of the endorhinal sulcus (es) one-third of the distance to the most convex point of the medial tem-
poral lobe. The perirhinal cortex is the caudal continuation of the temporopolar cortex. It represents the most
rostral aspect of the parahippocampal gyrus (PHG) and extends to the lateral bank of the collateral sulcus (cs).
(C) The entorhinal cortex (ERC) begins just caudal to the limen insulae, extending medially to the sulcus semian-
nularis (ssa) and laterally to the medial bank of the collateral sulcus. The PRC extends from there to the lateral
bank of the collateral sulcus. At this level, the PCA extends from the fundus of the endorhinal sulcus to the sulcus
semiannularis. (D) The amygdala (A) is just caudal to the limen insulae. The PCA, ERC, and PRC are all visible at this
level. (E) The semilunar gyrus (SLG) is separated from the ambient gyrus (AG) by the sulcus semiannularis. The
uncal notch (N) is visualized along the inferior surface of the AG. (F) The hippocampal head (HH) demonstrates
internal digitations (red arrows) with a thin overlying strip of alveus (A). The uncinate gyrus (UG) is visualized.
Note flattening and loss of internal digitations in the left hippocampal head. The hippocampal fissure (hf) sep-
arates the uncus (Un) from the PHG. (G) The caudal aspect of the right hippocampal head is demarcated by the
gyrus intralimbicus (GIL), which is the most caudal of the uncal bulges and is seen as a small, round superomedial
protrusion. The fimbria (F) is firmly adhered to its caudal extremity. (H) One slice caudal to the GIL, demarcating
the first slice of hippocampal body (HB). Note the fimbria (F) and fimbriodentate sulcus (fds); this is the last slice
that contains the ERC, whereas the PRC extends an additional slice and wraps medially behind the ERC. Beyond
that, the parahippocampal cortex continues along the medial aspect of the temporal lobe.

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 Medial Temporal Lobe Anatomy 485

Fig. 12. Hippocampal circuitry. (Top) (A–F) The components of the perforant path system largely identified in an-
imal studies. Major pathways are represented by solid lines, whereas minor pathways are represented by dotted
lines. (A) 5 “sublamina supratangentialis” (dotted red), a minor superficial entorhinal bundle projecting to the
parasubiculum and presubiculum. (B) 5 entorhinal projection to the angular bundle (yellow). (C) 5 angular
bundle fibers (yellow) perforating through the subiculum. D 1 E 5 these same fibers projecting superiorly (D)
into the dentate gyrus or inferiorly (E) into the hippocampal CA fields (yellow). F 5 angular bundle fibers subja-
cent to the subiculum projecting into the CA fields (alvear path, light blue). The remaining hippocampal circuitry
includes mossy fibers projecting from the dentate gyrus to CA3 and CA4 (dark blue), the endfolial pathway pro-
jecting from CA4 toward and through CA3 (light brown), CA3 projecting to the fornix (green) and to CA1
(Schaffer collaterals, orange), followed by CA1 and subiculum output to ERC and subicular output to the fornix
(green). CA, cornu ammonis; DG, dentate gyrus; ERC, entorhinal cortex; PaS, parasubiculum; PHC, parahippocam-
pal cortex; PRC, perirhinal cortex; PreS, presubiculum; ProS, prosubiculum; Sub, subiculum. (From Zeineh MM,
Palomero-Gallagher N, Axer M, et al. Direct Visualization and Mapping of the Spatial Course of Fiber Tracts at
Microscopic Resolution in the Human Hippocampus. Cereb Cortex. Published online February 13, 2016:bhw010.)

Fig. 13. Gross (A) and schematic (B) images depicting the superficial arteries and veins of the hippocampal body.
Cornu ammonis (CA) and CA1–4 subfields, dentate gyrus (D), alveus (aL), fimbria (F), fimbriodentate sulcus (fds),
superficial hippocampal sulcus (hs), parahippocampal gyrus (phg), basal vein of Rosenthal (bvr), middle and pos-
terior hippocampal arteries (mha and pha), posterior cerebral artery (pca), basilar artery (ba), vein of the fimbrio-
dentate sulcus (vfds), vein of the superficial hippocampal sulcus (vshs), vein of the temporal horn (vth), intrasulcal
hippocampal vein (ishv), inferior ventricular vein (ivv), medial atrial vein (mav), stratum pyramidale (sp), compi-
lation of strata radiatum, lacunosum, and moleculare (srlms), subiculum (S), superficial medullary lamina (sml),
entorhinal area (eh), margo denticulatus (md). (From Thomas BP, Welch EB, Niederhauser BD, et al. High-
resolution 7T MRI of the human hippocampus in vivo. J Magn Reson Imaging. 2008;28(5):1266-1272.)

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486 van Staalduinen & Zeineh

uncal sulcus, where it frequently anastomoses Incomplete hippocampal inversion and

with the uncal branch of the anterior choroidal hippocampal malrotation
artery.7 Incomplete hippocampal inversion refers to
The superficial hippocampal veins form 2 longi- abnormal hippocampal morphology resulting
tudinal venous arches along the fimbriodentate from a relative lack of hippocampal infolding dur-
and superficial hippocampal sulci, which join ing normal fetal development. This condition has
together at their anterior and posterior poles. The also been termed hippocampal malrotation or hip-
anterior pole flows into the inferior ventricular pocampal morphologic malformation, including
vein, whereas the posterior pole joins the medial the more commonly used term, globular hippo-
atrial vein. Both are tributaries of the basal vein campus.24,25 Although this entity has been re-
of Rosenthal, which ultimately join the vein of ported in patients with epilepsy25 and those with
Galen.7 congenital malformations26 with varying fre-
quencies, it also occurs in up to 19% of nonepilep-
tic patients,27 suggesting that hippocampal
Normal Hippocampal Variants malrotation is a common morphologic variation,
Sulcal remnant and choroidal fissure cysts and not clearly a causative lesion in patients with
Sulcal remnant (large arrow, Fig. 14) and choroidal temporal lobe epilepsy.28,29
fissure cysts (smaller arrow) are benign cerebral When detected, left-sided incomplete hippo-
cysts that are occasionally seen at the level of campal inversion is more common than bilateral,
the vestigial hippocampal sulcus and the choroidal and isolated right-sided hippocampal malrotation
fissure. Sulcal remnant cysts result from lack of is rare.27 It is assessed in the coronal plane at
obliteration of the hippocampal sulcus, thus they the level of the red nucleus and hippocampal
are most commonly located between the CA and body, classically demonstrating a round or pyrami-
dentate gyrus in the lateral aspect of the hippo- dal hippocampal shape, a deep collateral sulcus
campal apex. The cause of choroidal fissure cysts with increased vertical orientation, and a lateral-
is less clear, although developmental variation ized, somewhat prominent temporal horn. Hippo-
may occur along the choroidal fissure at the time campal signal intensity is normal (Fig. 15). This
of primitive choroid plexus formation. On MR im- entity is a lesser form along the spectrum of a ver-
aging, both types of cysts demonstrate signal in- tical hippocampus (a more complete and severe
tensity that follows cerebrospinal fluid on all form of hippocampal malrotation), which occurs
sequences without demonstrating contrast in developmental malformations such as
enhancement or restricted diffusion. Both are holoprosencephaly.
asymptomatic and incidentally discovered.5
Clinical Relevance
Temporal lobe epilepsy and hippocampal
sclerosis
Hippocampal sclerosis is characterized by
segmental pyramidal cell loss and gliosis and is
the most common histopathologic abnormality
found in adults with drug-resistant temporal lobe

Fig. 14. Coronal T2W-FSE MR image at 3T demon-

strates a small choroidal fissure cyst (long, thin arrow)
and a smaller sulcal remnant cyst in the vestigial hip-
pocampal sulcus (short, wide arrow). The fissures sur-
rounding the hippocampus are delineated, including
the ambient cistern (ac), transverse fissure (tf), and
choroidal fissure (cf). The hippocampal fissure is Fig. 15. Coronal T2W-FSE MR image at 3T through the
largely obliterated. The basal vein of Rosenthal (B) hippocampal body demonstrates incomplete left hip-
and posterior cerebral artery (P) are also labeled. pocampal inversion (arrow).

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 Medial Temporal Lobe Anatomy 487

epilepsy.30 Classic imaging features on MR from senescent volume loss or atrophy associated
include noticeable hippocampal atrophy and with other neurodegenerative disorders (e.g.,
increased signal intensity on T2-weighted images, PART or hippocampal sclerosis of aging).14,31–33
particularly involving the hilus (DG and CA4). One qualitative imaging assessment is the MTL at-
Another key imaging feature is altered architec- rophy score,34 whereas a more recently described
ture, specifically the loss of internal digitations qualitative assessment is the entorhinal cortical at-
anteriorly, and blurring of the gray-white matter rophy score.35 Reduced clarity of the SRLM is
junction, such that the SRLM is less conspicuous. another imaging feature described in those with
Secondary signs with less specificity are ipsilateral amnestic AD.31,32 A significant challenge in the
mammillary body and forniceal column volume strict use of volumetry is the wide distribution of
loss, ipsilateral temporal horn dilation, and volume among healthy populations, and it is
choroidal fissure widening. Hippocampal volume- important to judge if the hippocampal volume
try is an adjunct to visual inspection, and the de- loss is reflective of global volume loss or specific
gree of hippocampal subfield neuronal loss has to the hippocampus. In addition, there are hippo-
been shown to correlate with degree of atrophy.30 campal sparing forms of AD.36
Three main patterns of subfield neuronal loss and
gliosis are described by the International League Image Segmentation Software
Against Epilepsy, including type 1 (affecting CA1,
CA4, and DG regions), type 2 (CA1-predominant), Image segmentation software has become
and type 3 (CA4-predominant).30 An important increasingly useful for quantification in neuroimag-
adjunct to MR imaging findings is hypometabolism ing. Hippocampal subfield segmentation software,
on interictal PET, which characteristically extends such as FreeSurfer and Automatic Segmentation
to involve the temporal pole (Fig. 16). of Hippocampal Subfields, is currently more
research oriented, whereas several other auto-
Alzheimer disease mated segmentation software packages are
AD is a common progressive, ultimately fatal, Food and Drug Administration approved for clin-
neurodegenerative disorder and the most com- ical use, including IcoMetrix and NeuroQuant.
mon cause of dementia. Histopathologically, there These latter packages provide fully automated vol-
is extracellular b-amyloid plaques and neurofibril- umes of numerous brain structures, including ce-
lary tangles with progressive neuron and synapse rebral white and gray matter, hippocampus,
loss. Imaging has shown MTL volume loss with amygdala, and basal ganglia nuclei, which is clin-
disproportionate atrophy in the CA1 region, subic- ically relevant, as volumetric changes have been
ulum, and entorhinal cortex compared with normal implicated in neurodegenerative diseases, such
controls (Fig. 17), although these findings lack as AD, and can be helpful in discriminating volume
specificity and can be challenging to distinguish loss in mesial temporal sclerosis.

Fig. 16. Coronal T2W-FSE MR images at 3T through the hippocampal head (A) and body (B) demonstrate ILAE-
type 1 hippocampal sclerosis. There is loss of internal digitations with increased T2 signal and blurring of internal
architecture in the left hippocampal head (white arrows in (A). There is also atrophy of the left hippocampal body
with reduced clarity of the SRLM (yellow arrow in (B), compared with a normal SRLM on the right (red arrow).
Fused axial FDG-PET/MR image (C) demonstrates markedly decreased interictal metabolic activity in the left
medial temporal lobe.

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488 van Staalduinen & Zeineh

Fig. 17. Coronal (A) T1- and (B) T2-weighted MR images through the hippocampal body at 3T in a patient with
early onset Alzheimer disease, showing global and hippocampal volume loss.

SUMMARY

AD demonstrates disproportionate atrophy
The anatomic relationships of the MTL are fasci- in the CA1 region, subiculum, and entorhinal
nating and complex, including structural and func- cortex as well as reduced clarity of the SRLM,
tional anatomy of the hippocampal formation, the although it can be challenging to distinguish
parahippocampal region, and the amygdaloid these changes from overall brain volume loss
complex. As neuroimaging techniques continue and senescent changes.
to improve, an understanding of hippocampal sub-
field anatomy is requisite, as these structures will
be more clearly visualized, with clinical relevance DISCLOSURE
given their unique contributions to cognition and There are no relevant disclosures.
sensitivities to pathology.

REFERENCES
CLINICS CARE POINTS
1. Andersen P. The hippocampus book. New York: Ox-
ford University Press; 2007.
2. Insausti R, Amaral DG. Hippocampal formation. In:

Important anatomic landmarks for evalu- The human nervous system. Elsevier; 2012. p.
ating the MTL include the hippocampal 896–942. https://doi.org/10.1016/B978-0-12-
head/body/tail boundaries, the collateral sul- 374236-0.10024-0.
cus, limen insulae, uncal apex (gyrus intralim- 3. Lewis F. The significance of the term hippocampus.
bicus), and SRLM.
J Comp Neurol 1923;35:213–30.

Hippocampal malrotation refers to abnormal 4. Lorente de Nó R. Studies on the structure of the ce-
hippocampal morphology, characterized by a rebral cortex. II. continuation of the study of the am-
round or pyramidal hippocampal shape, a monic system. J Psychol Neurol 1934;46:113–77.
deep collateral sulcus with increased vertical
5. Dekeyzer S, De Kock I, Nikoubashman O, et al. Un-
orientation, and a lateralized position of a
forgettable” – a pictorial essay on anatomy and pa-
nondilated temporal horn. Hippocampal
signal intensity is normal. thology of the hippocampus. Insights Imaging 2017;
8(2):199–212.

Hippocampal sclerosis is characterized by
6. Kier EL, Kim JH, Fulbright RK, et al. Embryology of the
neuronal cell loss and gliosis, with specific
human fetal hippocampus: mr imaging, anatomy, and
types described by the International League
Against Epilepsy based on CA field involve- histology. AJNR Am J Neuroradiol 1997;18:525–32.
ment. MR imaging depicts hippocampal vol- 7. Duvernoy HM. The human hippocampus: functional
ume loss, increased signal on T2-weighted anatomy, vascularization and serial sections with
images, loss of internal digitations, blurring MRI. Springer Berlin Heidelberg; 2005. https://doi.
of the gray-white matter, ipsilateral mammil- org/10.1007/b138576.
lary body and forniceal column volume loss, 8. Zeineh MM, Palomero-Gallagher N, Axer M, et al.
ipsilateral temporal horn dilation, and Direct visualization and mapping of the spatial
choroidal fissure widening. course of fiber tracts at microscopic resolution in

Descargado para Anonymous User (n/a) en National Autonomous University of Mexico de ClinicalKey.es por Elsevier en diciembre 13, 2024. Para
uso personal exclusivamente. No se permiten otros usos sin autorización. Copyright ©2024. Elsevier Inc. Todos los derechos reservados.
 Medial Temporal Lobe Anatomy 489

the human hippocampus. Cereb Cortex. Published on magnetic resonance images: human medial tem-
online February 13, 2016:bhw010. doi:10.1093/cer- poral lobe landmarks. Hum Brain Mapp 2014;35(1):
cor/bhw010 248–56.
9. Fatterpekar GM, Naidich TP, Delman BN, et al. Cy- 24. Barsi P, Kenez J, Solymosi D, et al. Hippocampal
toarchitecture of the human cerebral cortex: MR mi- malrotation with normal corpus callosum: a new en-
croscopy of excised specimens at 9.4 tesla. AJNR tity? Neuroradiology 2000;42:339–45.
Am J Neuroradiol 2002;23:1313–21. 25. Bernasconi N, Kinay D, Anderman F, et al. Analysis
10. Dickson DW, Ruan D, Crystal H, et al. Hippocampal of shape and positioning of the hippocampal forma-
degeneration differentiates diffuse Lewy body dis- tion: an MRI study in patients with partial epilepsy
ease (DLBD) from Alzheimer’s disease. Neurology and healthy controls. Brain 2005;128:2442–52.
1991;41(9):1402. 26. Sato N, Hatakeyama S, Shimizu N, et al. MR evalua-
11. Amunts K, Kedo O, Kindler M, et al. Cytoarchitec- tion of the hippocampus in patients with congenital
tonic mapping of the human amygdala, hippocam- malformations of the brain. AJNR Am J Neuroradiol
pal region and entorhinal cortex: intersubject 2001;22:387–93.
variability and probability maps. Anat Embryol 27. Bajic D, Wang C, Kumlien E, et al. Incomplete inver-
(Berl) 2005;210(5):343–52. sion of the hippocampus—a common develop-
12. Thomas BP, Welch EB, Niederhauser BD, et al. High- mental anomaly. Eur Radiol 2008;18(1):138–42.
resolution 7T MRI of the human hippocampus 28. Bajic D, Kumlien E, Mattsson P, et al. Incomplete
in vivo. J Magn Reson Imaging 2008;28(5):1266–72. hippocampal inversion—is there a relation to epi-
13. Coras R, Milesi G, Zucca I, et al. 7T MRI features in lepsy? Eur Radiol 2009;19(10):2544–50.
control human hippocampus and hippocampal scle- 29. Tsai MH, Vaughan DN, Perchyonok Y, et al. Hippo-
rosis: an ex vivo study with histologic correlations. campal malrotation is an anatomic variant and has
Epilepsia 2014;55(12):2003–16. no clinical significance in MRI-negative temporal
14. Mueller SG, Stables L, Du AT, et al. Measurement of lobe epilepsy. Epilepsia 2016;57(10):1719–28.
hippocampal subfields and age-related changes 30. Blümcke I, Thom M, Aronica E, et al. International
with high resolution MRI at 4T. Neurobiol Aging consensus classification of hippocampal sclerosis
2007;28(5):719–26. in temporal lobe epilepsy: a task force report from
15. Insausti R, Córcoles-Parada M, Ubero MM, et al. Cy- the ILAE commission on diagnostic methods. Epi-
toarchitectonic areas of the gyrus ambiens in the hu- lepsia 2013;54(7):1315–29.
man brain. Front Neuroanat 2019;13:21. 31. Firbank MJ, Blamire AM, Teodorczuk A, et al. High
16. Naidich TP, Castillo M, Cha S, et al. Surface anatomy resolution imaging of the medial temporal lobe in
of the cerebrum. In: Imaging of the brain. Saunders; alzheimer’s disease and dementia with lewy bodies.
2012. p. 127–53. J Alzheimers Dis 2010;21(4):1129–40.
17. Ding SL. Comparative anatomy of the prosubiculum, 32. Su L, Hayes L, Soteriades S, et al. Hippocampal
subiculum, presubiculum, postsubiculum, and para- stratum radiatum, lacunosum, and moleculare
subiculum in human, monkey, and rodent: compara- sparing in mild cognitive impairment. In:
tive neuroanatomy of the subicular cortices. J Comp Hornberger M, editor. J Alzheimers Dis 2017;61(1):
Neurol 2013;521(18):4145–62. 415–24.
18. Bienkowski MS, Sepehrband F, Kurniawan ND, et al. 33. Yushkevich PA, Pluta JB, Wang H, et al. Automated
Homologous laminar organization of the mouse and volumetry and regional thickness analysis of hippo-
human subiculum. Sci Rep 2021;11(1):3729. campal subfields and medial temporal cortical
19. Insausti R, Juottonen K, Soininen H, et al. MR Volu- structures in mild cognitive impairment: Automatic
metric analysis of the human entorhinal, perirhinal, Morphometry of MTL Subfields in MCI. Hum Brain
and temporopolar cortices. AJNR Am J Neuroradiol Mapp 2015;36(1):258–87.
1998;19:659–71. 34. Scheltens P, Leys D, Barkhof F, et al. Atrophy of
20. Braak H, Braak E. Neuropathological stageing of medial temporal lobes on MRI in “probable” Alz-
Alzheimer-related changes. Acta Neuropathol heimer’s disease and normal ageing: diagnostic
1991;82(4):239–59. value and neuropsychological correlates. J Neurol
21. Pereira PMG, Insausti R, Artacho-Perula E, et al. MR Neurosurg Psychiatry 1992;55(10):967–72.
Volumetric analysis of the piriform cortex and 35. Enkirch SJ, Traschütz A, Müller A, et al. The ERICA
cortical amygdala in drug-refractory temporal lobe score: an MR imaging–based visual scoring system
epilepsy. AJNR Am J Neuroradiol 2005;26:319–32. for the assessment of entorhinal cortex atrophy in
22. Yilmazer-Hanke DM. Amygdala. In: The human ner- alzheimer disease. Radiology 2018;288(1):226–333.
vous system. Elsevier; 2012. p. 759–834. https:// 36. Whitwell JL, Dickson DW, Murray ME, et al. Neuroi-
doi.org/10.1016/B978-0-12-374236-0.10022-7. maging correlates of pathologically defined sub-
23. Frankó E, Insausti AM, Artacho-Pérula E, et al. Iden- types of Alzheimer’s disease: a case-control study.
tification of the human medial temporal lobe regions Lancet Neurol 2012;11(10):868–77.

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