Clinical features and outcome in North American adults with idiopathic basal arterial occlusive disease without moyamoya collaterals.

OBJECTIVE: To define the clinical characteristics and outcome of patients with idiopathic stenosis or occlusion of the basal arteries, without moyamoya collateral vessel formation.
METHODS: We identified patients who presented to our institution from 1996 to 2005 with occlusive disease of the distal internal carotid artery or the proximal middle or anterior cerebral arteries demonstrated by digital subtraction cerebral angiography. We excluded those with evidence of atherosclerotic disease, systemic vasculitis, moyamoya phenomenon, or any other condition that could otherwise explain their arterial occlusive disease. Medical records were reviewed for presenting symptoms and clinical characteristics. Outcome was determined from chart review and phone interviews.
RESULTS: Twelve patients were identified. All presented with transient ischemic attack or stroke. Eleven were women. Age at presentation ranged from 34 to 71 years. Nine had a history of hypertension; 5 had unilateral intracranial disease. Recurrent stroke on medical therapy occurred in none of the 5 during an average follow-up of 29 months. Seven had bilateral disease. Ischemic stroke occurred between 2 and 107 months after the initial event in 5 of 8 medically treated hemispheres. Moyamoya collateral vessels developed in 1 patient as shown on follow-up angiography.
CONCLUSION: The clinical features and outcome of these patients are similar to those reported in large case series of North American patients with moyamoya phenomenon. These data suggest a common etiology for the basal arterial occlusive process and a variable ability to form moyamoya collateral vessels.