Neurology India
menu-bar5 Open access journal indexed with Index Medicus
  Users online: 6663  
 Home | Login 
About Editorial board Articlesmenu-bullet NSI Publicationsmenu-bullet Search Instructions Online Submission Subscribe Videos Etcetera Contact
  Navigate Here 
 Resource Links
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
    Article in PDF (665 KB)
    Citation Manager
    Access Statistics
    Reader Comments
    Email Alert *
    Add to My List *
* Registration required (free)  

  In this Article
   Article Figures

 Article Access Statistics
    PDF Downloaded36    
    Comments [Add]    
    Cited by others 3    

Recommend this journal


Table of Contents    
Year : 2011  |  Volume : 59  |  Issue : 6  |  Page : 908-909

Acute embolic occlusion of the accessory middle cerebral artery mimicking an internal carotid artery terminus aneurysm

1 Department of Clinical Neuroscience, University of Calgary, Calgary, Alberta, Canada
2 Departments of Clinical Neuroscience, Radiology, Medicine, and Community Health Sciences, University of Calgary, Calgary, Alberta, Canada
3 Department of Clinical Neuroscience and Radiology, University of Calgary, Calgary, Alberta, Canada

Date of Submission26-Jul-2011
Date of Decision21-Aug-2011
Date of Acceptance10-Nov-2011
Date of Web Publication2-Jan-2012

Correspondence Address:
Mayank Goyal
Department of Clinical Neuroscience and Radiology, University of Calgary, Calgary, Alberta
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0028-3886.91378

Rights and Permissions

How to cite this article:
Menon BK, Aaron S, Bal S, Hill MD, Demchuk AM, Goyal M. Acute embolic occlusion of the accessory middle cerebral artery mimicking an internal carotid artery terminus aneurysm. Neurol India 2011;59:908-9

How to cite this URL:
Menon BK, Aaron S, Bal S, Hill MD, Demchuk AM, Goyal M. Acute embolic occlusion of the accessory middle cerebral artery mimicking an internal carotid artery terminus aneurysm. Neurol India [serial online] 2011 [cited 2021 Jun 20];59:908-9. Available from:


A 58-year-old right hand dominant male presented with acute left hemi-paresis and hemi-neglect on waking up with a National Institute of Health Stroke Score (NIHSS) of 14. He was last seen normal 7 h ago. Non-contrast computed tomography (NCCT) showed early ischemic changes in the right middle cerebral artery (MCA) territory. CT angiogram (CTA) showed a 2-mm aneurysmal dilatation at the right internal carotid artery (ICA) terminus with origin stenosis of 70% by North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria and an intraluminal thrombus with no intracranial occlusion. The patient was not treated with intravenous tPA due to uncertain time of onset and received antithrombotics. An endovascular approach was not considered due to probable subacute changes on NCCT and absence of intracranial occlusion on initial CTA. A repeat CTA after three days to evaluate for the intraluminal thrombus at the right ICA origin incidentally also showed a partially recanalized right accessory MCA. This had been previously reported as a 2-mm aneurysmal dilatation of the right ICA terminus in the CTA at presentation [Figure 1]. The patient showed only marginal clinical improvement at discharge.
Figure 1: NCCT at baseline shows early ischemic changes in the corona radiata (a). Some of the changes are well evolved. CTA at baseline shows patent MCA branches on the right (b) and what seems like an ICA terminus aneurysmal dilatation (arrow). Follow-up NCCT shows final infarct extent (c) with (d) CTA showing the partially recanalizing accessory MCA (arrow)

Click here to view

Accessory MCA is a rare anatomical variant arising from either the ICA or the anterior cerebral artery with estimated incidence of 0.3-4 %. [1] It was first described by Crompton in 1962 as an artery running through the sylvian fissure along with the MCA and vascularizing part of the cortical and subcortical territory of the MCA. [2] The first angiographic description of this artery was by Krayenbuhl and Yasargil in 1965. [1] Subsequent publications by others established the presence of this rare anatomical variant conclusively. [1],[3],[4] Komiyama et al.,[5] have previously described two cases of acute embolic occlusion of ICA and MCA in association with a patent accessory MCA. To our knowledge this is the first such case to be reported in the literature.

Phylogenetically, the MCA develops after Anterior cerebral artery (ACA) with the ACA considered as a continuation of the primitive ICA. [1] The MCA is regarded as a branch of the ACA and is the newest of large cerebral vessels, supplying the most recently developed telencephalon. Accessory MCA is an artery that runs parallel to the MCA and supplies a part of the vascular territory of the MCA. [1] Little is however known about the ontogeny or embryology of this artery that has an estimated incidence of 0.31-4%. [1] Teal et al., [4] first described two types of accessory MCA: true accessory MCA originating from the ipsilateral anterior cerebral artery near the anterior communicating artery, and the duplicated MCA originating from the distal ICA between the anterior choroidal artery and the terminal bifurcation of the ICA. The true MCA was identified as the larger of the two MCAs. [4] Abanou et al., [1] described three anatomical subtypes of accessory MCA: Type 1 when it arises from ICA; Type 2 when the origin is the proximal A1 ACA, and Type 3 when it arises from the distal segment of the A1 ACA near the anterior communicating artery. Handa et al., [3] thought that it was a hypertrophied recurrent artery of Huebner. This explanation however was flawed as the accessory MCA often coexisted with a recurrent artery of Huebner. This accessory MCA can be regarded as an enlarged "Recurrent artery of Huebner" vessel having subcortical and cortical branches. [6] We subscribe to this explanation. Knowledge of the existence of this rare anatomical variant is essential when making intra-arterial treatment decisions in acute ischemic strokes.

  References Top

1.Abanou A, Lasjaunias P, Manelfe C, Lopez-Ibor L. The accessory middle cerebral artery (amca). Diagnostic and therapeutic consequences. Anat Clin 1984;6:305-9.  Back to cited text no. 1
2.Crompton MR. The pathology of ruptured middle-cerebral aneurysms with special reference to the differences between the sexes. Lancet 1962;2:421-5.  Back to cited text no. 2
3.Handa J, Shimizu Y, Matsuda M, Handa H. The accessory middle cerebral artery: Report of further two cases. Clin Radiol 1970;21:415-6.  Back to cited text no. 3
4.Teal JS, Rumbaugh CL, Bergeron RT, Segall HD. Anomalies of the middle cerebral artery: Accessory artery, duplication, and early bifurcation. Am J Roentgenol Radium Ther Nucl Med 1973;118:567-75.  Back to cited text no. 4
5.Komiyama M, Nishikawa M, Yasui T. The accessory middle cerebral artery as a collateral blood supply. AJNR Am J Neuroradiol 1997;18:587-90.  Back to cited text no. 5
6.Lasjaunias P, Berenstein A. Internal Carotid Artery (ICA) Anterior Division, III: Surgical Neuroangiography. Berlin, Germany: Springer-Verlag; 1990. p. 111-51.  Back to cited text no. 6


  [Figure 1]

This article has been cited by
1 Subdural Hygroma After Craniosynostosis Remodeling Surgery
Praveen Ganesh,Muralidhara Nagarjuna,Samarth Shetty,Paul C. Salins
The Journal of Craniofacial Surgery. 2015; 26(1): 193
[Pubmed] | [DOI]
2 Cerebral Infarction Associated with Accessory Middle Cerebral Arteries: Two Case Reports
Yu Hiramatsu,Masayuki Wakita,Hideki Matsuoka,Jyunji Kasuya,Rikuzo Hamada,Hiroshi Takashima
Internal Medicine. 2014; 53(12): 1381
[Pubmed] | [DOI]
3 Intravenous t-PA for the occlusion of an accessory MCA
Kuwahara, H. and Matsumura, K. and Watanabe, M. and Fujigasaki, H.
Internal Medicine. 2013; 52(1): 163


Print this article  Email this article
Online since 20th March '04
Published by Wolters Kluwer - Medknow