The arteriograms of 109 patients with symptomatic cerebral ischemia were analyzed to determine the distribution of extracranial and intracranial vascular abnormalities. In the 66 patients with transient hemispheric or ocular ischemia, potentially embolic lesions were more common than hemodynamically significant lesions (84% versus 50%). In the 29 patients with fixed neurologic deficits, 25% had occlusion of the internal carotid artery on the appropriate side; ulcerated lesions were again more common in the remaining patent arteries than were hemodynamically significant lesions. The major difference between the transient group and the fixed group was the 29% incidence of intracerebral disease or anomaly in the transient group, with similar lesions in 90% of the group with fixed neurologic deficit. Symptoms of cerebral ischemia are more likely to be related to ulceration than to hemodynamically significant lesions. The risk of stroke seems greatest when there is also intracerebral siphon disease or anatomic anomaly of the circle of Willis.
Thiele et al. (Wed,) studied this question.