Limitations of the Doppler cerebrovascular examination in hemispheric cerebral ischemia.

The results of a directional Doppler ultrasound cerebrovascular examination were compared with arteriographic findings in 56 patients with resolved hemispheric strokes or transient ischemic attacks. Aortic arch arteriography revealed appropriate internal carotid artery lesions which were amenable to endarterectomy in 36 patients (64 percent). Of this group, abnormal Doppler findings were present in only 11 patients (31 percent). The definitive clinical applications of the Doppler cerebrovascular examination are limited to those settings in which demonstration of altered hemodynamics is decisive. In view of the apparent preponderance of embolic rather than hemodynamic mechanisms in the pathogenesis of focal cerebral ischemia, the Doppler examinations has only an adjunctive role in the evaluation of most patients with hemispheric symptoms of cerebrovascular occlusive disease. In such patients, preselection of candidates for diagnostic arteriography is an inappropriate application of the Doppler cerebrovascular examination.