Rare Neurovascular Variants Arising from the Internal Carotid Artery

Gajjar, M.; Honarmand, A.R.; Patel, B.M.; Hurley, M.C.; Shaibani, A.; Ansari, S.A.

View Article on Neurographics Website

Date of Activity Release: Aug. 1, 2016
Date of Activity Expiration: Aug. 1, 2019

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

Learning Objectives:
Review anatomic variations of the internal carotid artery (ICA), including imaging appearances, embryologic development, prevalence, and associations of clinically relevant variants with neurovascular pathology.

We reviewed rare cervical and intracranial ICA anatomic variants, aberrant ECA origins; aberrant or aplastic ICAs; CCA absence; persistent proatlantal, stapedial, hypoglossal, and trigeminal arteries; primitive maxillary and mandibular arteries; and duplicated posterior communicating arteries, including a persistent primitive fetal branch or hyperplastic anterior choroidal artery, infraoptic anterior cerebral artery, and dorsal-ventral ophthalmic arteries. Variants of the ICA are rare, typically asymptomatic, and incidental findings. However, these variants can occasionally influence surgical or endovascular strategies, temporary occlusion times, inadvertent embolization risk, and collateral pathways, with a potential impact on procedural complications and patient outcomes.

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

Michele Johnson

Associate Editor

Consultant, Boston Scientific, Inc.

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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