Adult onset moyamoya disease: institutional experience.

Moyamoya disease is a progressive steno-occlusive disease of bilateral carotid forks with the formation of fine collateral vascular network and is an angiographic diagnosis. We analyzed case records of 11 patients with "adult-onset moyamoya disease." Six patients presented with intracranial hemorrhage (intracerebral and/or intraventricular) and 5 with focal ischemia. Angiography revealed bilateral Internal carotid artery involvement in 8 patients and unilateral involvement in 3. Posterior cerebral artery involvement was seen in 3 patients. Saccular aneurysm involving posterior circulation was seen in only 1 patient. Although rare, adult-onset moyamoya disease should be considered as one of the causes for intracerebral and intraventricular hemorrhage in adults.