Neuropsychological signs of asymptomatic carotid stenosis

Several investigators have reported cognitive deficits associated with symptomatic carotid artery disease. This paper reports the findings of a study investigating cognitive deficits associated with asymptomatic carotid stenosis. Experimental subjects consisted of six patients who, in the course of routine physical examinations, showed carotid bruits and, on carotid ultrasound studies, showed 70% or greater stenosis in one or both arteries. No clinical symptoms had been associated with that stenosis. Six control subjects who were group-matched in terms of age and years of education were drawn from a control group evaluated previously for comparison with a transient ischemic attack (TIA) sample. All patients received a battery of tests consisting of a Wechsler Adult Intelligence Scale-Revised, abbreviated Halstead-Reitan Neuropsychological Battery, Revised Wechsler Memory Scale, and a written word fluency measure. Findings were converted to Rating Equivalents according to standard guidelines and an average Impairment Index was computed for each subject. ANOVA revealed that the two groups were significantly different in terms of the average Impairment Index. The clinical significance of these findings is discussed and implications for future research are reviewed.