Hemispheric TIA and amaurosis fugax: what is their relation to stenotic lesions of internal carotid artery?

We evaluated the correlation of clinical and echo-Doppler findings from the internal carotid artery (ICA) in 17 patients with amaurosis fugax (AF) and in 68 patients with hemispheric TIA (H-TIA). In the study population as a whole, moderate stenoses (20%-49% diameter reduction) were the most prevalent finding in the symptomatic ICA, being detectable in 51.6% of cases. Total occlusions were found in an unexpectedly high percentage (7.5%). Asymptomatic ICAs, that were contralateral to the symptoms, showed the same degree of atherosclerotic involvement as the symptomatic ICAs. When we compared AF with H-TIA, we found a significantly higher prevalence of severe hemodynamically significant stenoses in the former (52.6% vs. 18.8%, chi-square test 10.85, P less than 0.05). Thus, we conclude that in the vast majority of patients with transient neurological symptoms a bilateral ICA involvement is to be expected. The side on which the symptoms occur does not indicate which ICA is more severely stenotic except in AF, where a severe involvement of the ipsilateral ICA is most likely.