Racial differences in the distribution of anterior circulation occlusive disease.

We compared clinical and angiographic features of 26 white and 45 black patients with symptomatic occlusive cerebrovascular disease. White patients had more transient ischemic attacks, carotid bruits, and more severe occlusive disease of the internal carotid artery origin. Blacks had more severe disease of the middle cerebral artery stem and supraclinoid internal carotid arteries. Differences were not explained by racial differences in the prevalence of hypertension, diabetes, hypercholesterolemia, or ischemic heart disease. Since the middle cerebral artery lesions in blacks do not correlate with other accepted epidemiologic, clinical, and laboratory markers of atherosclerosis, the lesions may arise from a disorder that differs from atherosclerosis.