Middle Cerebral Artery Stenosis Associated with Moyamoya Pattern Collateralization

BACKGROUND AND PURPOSE Moyamoya disease is a well described phenomenon. This pattern of collateralization associated with isolated middle cerebral artery stenosis and the natural history of this entity have not been well described. METHODS Cerebral angiograms and CT angiograms performed between August 2004 and August of 2006 demonstrating moyamoya collateralization were retrospectively reviewed. All cases of middle cerebral artery stenosis associated with a rete pattern of collateralization were included in this series. Demographic, clinical, and angiographic data were obtained. RESULTS There were three cases of middle cerebral artery stenosis associated with a moyamoya pattern of collateralization. The average age of the patients was 36-years old, 2 were male, and all were Caucasian. All patients presented with ischemic symptoms. The average degree of stenosis was 91%. No stenosis was seen in the supraclinoid internal carotid arteries or elsewhere in the intracranial vasculature. CONCLUSION We describe an unusual pattern of anastomosis associated with isolated severe middle cerebral artery stenosis or occlusion in Caucasians.