Extracranial Cerebrovascular Disease

Abstract

It is now well established that a very significant percentage of intracranial ischemic lesions are due primarily to occlusive disease of the extracranial carotid and vertebral arteries. Although the manifestations of cerebral ischemia should alert one to this possibility, it is often difficult, on a clinical basis alone, to determine whether the lesion is in the intracranial or extracranial arteries. The presence of brachiocephalic bruits, weak or absent pulses in the neck or upper extremities, and significant discrepancy in blood pressure between the 2 arms strongly suggest the presence of occlusive disease of the carotid, vertebral, innominate, or subclavian arteries. Of the various diagnostic procedures discussed, adequate cerebral angiography offers the only satisfactory method of localizing the site of stenosis or occlusion. Because of the involvement of multiple vessels by the occlusive process, complete radiographic evaluation of all 4 extracranial cerebral arteries is desirable before therapy is considered. Anticoagulation and revas-cularization procedures are the most widely employed modalities of management. Because of the inherent dangers of long-term anticoagulation and the lack of evidence that it is effective in preventing progression of the disease, it is of limited usefulness. Surgical intervention, however, by restoring adequate blood flow to the brain has been demonstrated to be effective in preventing recurrent ischemic episodes. Very careful selection of candidates for surgery is necessary if these results are to be attained.