Spontaneous bilateral dissections of the intracranial vertebral arteries: a case report.

A 41-year-old woman died of subarachnoid hemorrhage. She had had severe headaches for 10 days, but no abnormalities were detected on the brain computer tomography (CT) taken about a half day prior to her death. At autopsy, bilateral dissecting aneurysms were found in the intracranial vertebral arteries. Headaches related to dissection are considered to be due to distension of the artery, and the dissection may have occurred 10 days before her death. In considering the brain CT and autopsy findings, subaracnoid hemorrhage may have occurred within several hours of death. Although multivessel dissections suggest the possibility of underlying angiopathy, the present case had no clear finding of angiopathy in any of the brain vessels. When one sees subarachnoid hemorrhage in the basal area of the brain and finds "black" or "bluish black" discoloration(s) in the circle of Willis, one should suspect a dissecting aneurysm(s).