Camping Out in the Hippocampus: Imaging Spectrum of Etiologies That Affect the Hippocampi and Tips for Honing the Differential Diagnosis

K. Hammoud, N. Spittler, K. Buch, R. Hakimelahi, J. Nguyen, and M. Lanfranchi

View Article on Neurographics Website

Date of Activity Release: Feb. 1, 2019
Date of Activity Expiration: Feb. 1, 2022

Target Audience:
Intended for neuroradiologists and neuroradiology trainees with varying degrees of experience.

Learning Objective:
To (1) review the normal hippocampal anatomy, function, and development; (2) recognize common hippocampal pathologies by reviewing original cases that illustrate the spectrum of hippocampal disease; and (3) become aware of the potential pitfalls, variants, and developmental anomalies related to the hippocampus that may confound evaluation for pathology.

The hippocampus is a complex anatomic structure characterized by interlocking folds of gray matter situated within the medial temporal lobes. As a crucial structure within the limbic system, it plays a vital role in memory formation and emotional decision-making. The hippocampi are susceptible to a heterogenous spectrum of pathologies related but not limited to degenerative, ischemic, drug-related, infectious, metabolic, autoimmune-mediated, and neoplastic etiologies. These include hippocampal sclerosis, Alzheimer disease and frontotemporal dementia, transient global amnesia, herpes simplex encephalitis, mitochondrial encephalopathy with lactic acidosis and strokelike episodes, ischemic and hemorrhagic infarction, seizure-related edema, autoimmune and paraneoplastic limbic encephalitis, and gliomatous lesions. Although imaging findings for some of these entities often overlap, which renders them potentially difficult to distinguish from one another, attention to both the imaging and clinical findings is important in narrowing the differential diagnosis.

Commercial Support
No commercial support was received for this activity.

Credit Designation Statement

The American Society of Neuroradiology is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.

The American Society of Neuroradiology designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 Credit(s)TM. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Method of Physician Participation:
Each participant will review the corresponding Neurographics article located at Upon completion, each physician will complete and pass a post-test with a score of at least 80% to receive a CME certificate.

All individuals in control of content have disclosed the following relevant financial relationships. All of these relationships were treated as a conflict of interest, and have been resolved (C7 SCS 6.1-6.2, 6.5)

Authors have no relevant financial relationships.





Barton Branstetter 

Editor in Chief

None, N/A

Adam Flanders

Deputy Editor

Royalties, Lippincott Williams and Wilkins

Robert Quencer 

Consulting Editor

None, N/A

Mark Mullins

Associate Editor

Non-remunerative position, AUR6

Meng Law

Associate Editor

Stockholder, Clinical Imaging

Edward Escott

Associate Editor

Grant, Atherysys, Inc.; Royalties, Thieme Medical Publishers

Scott Faro

Associate Editor

None, N/A

Tina Young Poussaint

Associate Editor

None, N/A

Dheeraj Ghandi

Associate Editor

Grant, Arstasis, Axera Inc.; Consultant, Covidien, EV3

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