Unilateral watershed cerebral infarcts.

We studied 51 patients with symptomatic unilateral watershed (WS) cerebral infarct on CT. In 22 patients, the infarct was between the superficial territory of the anterior and middle cerebral arteries, 20 had an infarct between the superficial territory of the middle and posterior cerebral arteries, and 9 had an infarct between the superficial and deep territory of the middle cerebral arteries. Each type had a characteristic neurologic picture. Syncope at onset (37%) and focal limb shaking (12%) were frequent. Thirty-eight patients (75%) had internal carotid artery occlusion or tight stenosis associated with a hemodynamically significant cardiopathy, increased hematocrit, or acute hypotension. Embolic infarction was probable in only two patients (4%) who had only atrial fibrillation.