Management of middle cerebral artery dissecting aneurysm

SummaryBackgroundDissecting aneurysms of the intracranial carotid circulation were previously thought to occur primarily in young people presenting with cerebral infarction caused by arterial stenosis and occlusion. The appropriate management of dissecting aneurysms in the anterior circulation remains controversial, especially in patients who also present with cerebral infarction. However, recent studies have reported better outcomes for patients with middle cerebral artery (MCA) dissecting aneurysms involving surgically treated subarachnoid hemorrhage (SAH). The purpose of this study is to describe a case of spontaneous SAH from rupture of a dissecting aneurysm in the M2 segment observed in a 79-year-old man with no sign of an ischemic neurological deficit, and also to review the clinical and radiological features of cases reported since 1990.MethodsOur review of the literature identified 24 cases of MCA dissecting aneurysms after 1990.ResultsOf the patients in these cases, 15 (63%) presented with pure bleeding and 7 (29%) with ischemia, and two were detected incidentally. Our review also found that the outcome of patients presenting with pure bleeding differed from those with ischemia. Patients with an MCA dissecting aneurysm who presented with pure bleeding showed better outcomes if they had surgery than if they did not. In contrast, the appropriate management of patients with a dissecting aneurysm who present with ischemia remains controversial.ConclusionOur review found that the clinical course of patients presenting with ischemia differed from that of patients presenting with pure bleeding. Most of the patients with ischemia underwent progressive deterioration. However, while the outcome for patients with ischemia treated surgically was relatively good, it remained poor compared to the outcome for patients who had been bleeding.