This case illustrates a catastrophic subarachnoid bleed secondary to a ruptured right anterior choroidal artery aneurysm, that was not amenable to surgical nor interventional treatment. Narrow caliber vessel and luminal enhancement abnormalities were identified (on CT angiography) in the A1 segments of the anterior cerebral arteries, M1 segments of the middle cerebral arteries and distal internal carotid arteries. These vessel abnormalities were later confirmed with cerebral angiography to be consistent with Moya Moya disease. 

Case courtesy of Associated Professor Pramit Phal