ASYMPTOMATIC CEREBRAL EMBOLIC SIGNALS IN PATIENTS WITH CAROTID STENOSIS - CORRELATION WITH APPEARANCE OF PLAQUE ULCERATION ON ANGIOGRAPHY

Background and Purpose Asymptomatic cerebral emboli may be detected in patients with carotid stenosis by transcranial Doppler ultrasonograph y of the middle cerebral artery (MCA). The aim of this study was to de termine the angiographic correlates of such embolic signals. Methods D oppler signals from 48 MCAs in 26 patients with carotid stenosis that was either symptomatic (n=20) or asymptomatic (n=6) were recorded for 40 minutes. The grade of carotid stenosis and the ulcerated or nonulce rated appearance of the plaque were assessed using the criteria of the North American Symptomatic Carotid Endarterectomy Trial. Results Embo lic signals were detected in 8 MCAs from 7 patients; 4 (50%) of these MCAs were clinically symptomatic compared with 16 (40%) without emboli c signal. Although there was a trend toward more severe stenosis in th e cases with embolic signals, this was not significant (mean+/-SD, 67/-29% versus 55+/-36%). In contrast, an image of ulceration was found on ipsilateral carotid angiography in 5 cases (63%) with embolic signa ls and in only 9 cases (23%) without embolic signals (odds ratio, 5.74 ; 95% confidence interval, 1.15 to 28.79, by multivariate regression a nalysis). Conclusions This study demonstrates that the occurrence of e mbolic signals in patients with carotid stenosis is associated with th e appearance of plaque ulceration on angiography.