Background: We report a vascular abnormality of the middle cerebral artery (MCA) that has not been described in the literature before. Methods: Two patients (1 male and 1 female; age 44 and 67 years, respectively) were found to have a vascular abnormality in which the main trunk of the MCA had a twig-like form. Both patients presented with intracranial hemorrhage. Results: In these 2 patients, the abnormality was seen before the genu of the MCA. They had an intracranial hemorrhage due to an associated aneurysm inside the twigs. The twig appeared to be a network between the bifurcation of internal carotid artery and insular segment of MCA, and it was different from the collateral circulation due to acquired occlusion or moyamoya disease. Conclusion: This new type of vascular lesion of the MCA is not benign. It appears to be associated with the occurrence of an aneurysm, an important clinical aspect.

Keywords:
Middle cerebral artery, Twig, Aneurysm, Hemorrhage, Surgery
1.
Teal JS, Rumbaugh CL, Bergeron RT, Segall HD: Anomalies of the middle cerebral artery: Accessory artery, duplication, and early bifurcation. AJR 1973;118:567–575.
2.
Crompton MR: The pathology of ruptured middle cerebral aneurysms with special reference to the differences between sexes. Lancet 1962;2:421–425.
3.
Jain KK: Some observations on anatomy of middle cerebral artery. Can J Surg 1964;7:134–139.
4.
Watanabe T, Togo M, Shibuya S, Yoshida Y, Amo M, Fukumitsu T: The accessory middle cerebral artery (in Japanese). No Shinkei Geka 1975;3:31–35.
5.
Yamamoto H, Marubayashi T, Soejima T, Matsuoka S, Matsukado Y, Ushio Y: Accessory middle cerebral artery and duplication of middle cerebral artery – terminology, incidence, vascular etiology, and developmental significance. Neurol Med Chir (Tokyo) 1992;32:262–267.
6.
Umansky F, Dujovny M, Ausman JI, Diaz FG, Mirchandani HG: Anomalies and variations of the middle cerebral artery: A microanatomical study. Neurosurgery 1988;22:1023–1027.
7.
Sanders WP, Sorek PA, Mehta BA: Fenestration of intracranial arteries with special attention to associated aneurysms and other anomalies. Am J Neuroradiol 1993;14:675–680.
8.
Ito J, Maeda H, Inoue K, Onishi Y: Fenestration of the middle cerebral artery. Neuroradiology 1977;13:37–39.
9.
Padget DH: The development of the cranial arteries in the human embryo. Contr Embryol Carneg Instn 1948;32:205–261.
10.
Gailloud P, Albayram S, Fasel JHD, Beauchamp NJ, Murphy KJ: Angiographic and embryologic considerations in five cases of middle cerebral artery fenestration. Am J Neuroradiol 2002;23:585–587.
11.
Uchino A, Kato A, Takase Y, Kudo S: Middle cerebral artery variations detected by magnetic resonance angiography. Eur Radiol 2000;10:560–563.
12.
Koyama S, Kotani A, Sasaki J, Tazoe M, Tsubokawa T: Ruptured aneurysm at the origin of duplication of the middle cerebral artery – case report. Neurol Med Chir (Tokyo) 1995;35:671–673.
13.
Handa J, Matsuda M, Okamoto K, Kidooka M: Association between accessory middle artery and cerebral aneurysm. Report of two cases. Acta Neurochir (Wien) 1982;64:151–157.
14.
Takahashi T, Suzuki S, Ohkuma H, Iwabuchi T: Aneurysm at a duplication of the middle cerebral artery. Am J Neuroradiol 1994;15:1166–1168.
15.
Han DH, Gwak HS, Chung CK: Aneurysm at the origin of accessory middle cerebral artery associated with middle cerebral artery aplasia: Case report. Surg Neurol 1994;42:388–391.
16.
Nagano T, Tochinai H, Endo H, Saiki I, Kanaya H: Two cases of accessory middle cerebral artery associated with intracranial aneurysm. Neurochirurgia (Stuttg) 1988;31:166–168.
17.
Sugita S, Yuge T, Miyagi J, Fujimura N, Shigemori M: Giant aneurysm at the origin of the accessory middle cerebral artery. Surg Neurol 1995;44:128–130.
18.
Stabler J: Two cases of accessory middle cerebral artery, including one with an aneurysm at its origin. Br J Radiol 1970;43:314–318.
19.
In S, In K, Kusano N, Mizuki H, Miyagi J, Kuramoto S: A case of duplication of the middle cerebral artery with ruptured aneurysm on its origin during pregnancy (in Japanese). No Shinkei Geka 1981;9:337–341.
20.
Miyazaki S, Ito K, Ishii S: Aneurysm at the origin of the accessory middle cerebral artery. Surg Neurol 1984;22:292–294.
21.
Isono M, Abe T, Goda M, Ishii K, Kobayashi H: Middle cerebral artery dissecting aneurysm causing intracerebral hemorrhage 4 years after the non-hemorrhagic onset: a case report. Surg Neurol 2002;57:346–349.
22.
Kurino M, Yoshioka S, Ushio Y: Spontaneous dissecting aneurysms of anterior and middle cerebral artery associated with brain infarction: A case report and review of the literature. Surg Neurol 2002;57:428–436.
23.
Ohkuma H, Susuki S, Shimamura N, Nakano T: Dissecting aneurysm of the middle cerebral artery: Neuroradiological and clinical features. Neuroradiology 2003;45:143–148.
© 2005 S. Karger AG, Basel
2005
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.