Aneurysm arising from Duplicated Middle Cerebral Artery: Case Report

A case of duplication of the middle cerebral artery and an aneurysm at its origin is described. The patient, a 74-year-old male, was hospitalized following a head injury. A computed tomography scan showed intraventricular and subarachnoid hemorrhages. Carotid and vertebral angiograms revealed no vascular abnormalities causative of the hemorrhages. However, duplication of the middle cerebral artery and a saccular aneurysm at its origin were coincidentally observed on the right side. Craniotomy was performed 3 weeks later, and the duplication was confirmed. The neck of the unruptured aneurysm was clipped. Of the 55 reported cases of duplication of the middle cerebral artery, only six were associated with an aneurysm at the origin. The possible etiologies of such aneurysms are discussed.