Idiopathic supraclinoid and internal carotid bifurcation steno-occlusive disease in young American adults

We report a series of American adults with idiopathic steno-occlusive disea se of the supraclinoid internal carotid artery and its bifurcation. We revi ewed the clinical records and imaging of 18 patients, 16 women and 2 men, a ged 20-53 years (mean 35 years). There were no predominating risk factors f or vascular occlusive disease, such as oral contraceptive use, hypertension , diabetes mellitus, or smoking. Four patients had irregularity of their ce rvical internal carotid arteries in a pattern not classic but suspicious of fibromuscular dysplasia. Eleven patients met the criteria for moyamoya dis ease, having both bilateral disease and moyamoya collateral lenticulostriat e arteries. Necropsy in one case showed intimal thickening with duplication of the internal elastic lamina involving the internal carotid artery bifur cation bilaterally. We found a marked predominance of young and middle-aged females in our American adults, but our findings do not support the associ ation with birth-control pills previously reported.