Clinical and angiographic features of carotid circulation thrombus.

We studied five patients with intraluminal carotid thrombus visualized by angiography. The distinctive clinical features included the following: thrombus formation without significant atherostenosis; peripheral and cerebral arterial thrombosis; step-wise evolution of cerebral and/or peripheral signs over a period of days to several weeks; clotting tendency despite heparin anticoagulation; and carotid or iliac artery thrombosis after thrombo-endarterectomy. These unusual features serve to identify an uncommon subgroup of stroke patients with large artery thrombosis. Pathogenesis was not established. Coagulopathy with elevated factor VIII levels was the suspected mechanism.