Noninvasive diagnosis of extracranial cerebrovascular disease

Abstract

The ability of two noninvasive diagnostic methods—oculoplethysmography-carotid phonoangiography (OPG/CPA) and directional Doppler ultrasonography—to detect extracranial cerebrovascular disease was examined in 400 consecutive studies. Cerebral arteriography was performed in 74 patients. Transient ischemic attack was the most common indication for study (30 percent). The OPG was normal in 95 percent of cases in which the diameter of the lumen of the internal carotid artery (ICA) was less than 60 percent reduced; the ocular pulse was delayed in 86 percent of cases with ICA stenosis of 60 percent or more. The overall diagnostic accuracy of OPG was 93 percent; CPA did not enhance the accuracy of OPG alone. Supraorbital Doppler tests detected 88 percent of cases of ICA stenosis of 60 percent or more, but there was a 13 percent false-positive rate with ICA stenosis of less than 60 percent. Supratrochlear Doppler tests had only a 1 percent false-positive rate, but detected only 48 percent of significant ICA stenoses. Doppler studies were most often abnormal in the presence of ICA occlusion. Thus, OPG was as sensitive as supraorbital Doppler and more sensitive than supratrochlear Doppler in detecting hemodynamically significant ICA stenoses, without the unacceptable false-positive rate observed with the supraorbital Doppler test.