IQ and neuropsychological changes following carotid endarterectomy

Abstract

Recently published studies have reported clinically significant increases in cognitive functioning in humans following surgical removal of obstructive atheromatous placque from the carotid artery leading from the heart to the brain. Detailed study by us of test-retest changes in group means in our own setting as well as scrutiny of similar test-retest scores for each individual patient comprizing our group of 17 carotid endarterectomy patients, and comparing them to similar detailed analyses in our one normal sample and two additional patient samples which served as reference groups, failed to confirm these earlier reported findings. Rather, our test-retest results with the full WAIS and 11 measures from the Halstead-Reitan Battery were little different from the test-retest changes found in these three reference groups which underwent no surgery. We concluded that the clinically unremarkable changes found in our endarterectomy and three reference samples are little different from the test-retest practice effect changes so long discussed in the literature of clinical psychology but which, unfortunately, rarely are published individual-by-individual thereby providing a data base against which to evaluate the effects of surgery, drug administration, or other intervention.