[Dissecting aneurysm of the middle cerebral artery (M1-2 portion) with subarachnoid hemorrhage: a case report].

We report a SAH case of a ruptured dissecting aneurysm of the middle cerebral artery following parietooccipital subcortical hemorrhage. A 68-year-old woman was admitted to our hospital, complaining of headache. On admission she was alert with left homonymous hemianopsia. A CT scan disclosed subcortical hemorrhage in the right parieto-occipital lobe. An angiogram revealed no abnormal vessels. Seven days after admission, she suddenly lapsed into unconsciousness with left hemiparesis. A CT scan demonstrated subarachnoid hemorrhage with a right sylvian hematoma. A second angiogram revealed fusiform dilatation of the M2 branches and aneurysmal dilatation at the M1-M2 bifurcation. Following conservative therapy, she died 21 days after admission. The relationship between subcortical hemorrhage and the subsequent subarachnoid hemorrhage was not certain. We discuss and review the treatment of a dissecting aneurysm of the middle cerebral artery.