Neuropsychological changes in patients with carotid stenosis after carotid endarterectomy

We investigated changes in neuropsychological function in patients with carotid stenosis following carotid endarterectomy (CEA) in relation to cerebral hemodynamics. The subjects were 24 patients who underwent CEA and 17 healthy controls matched by age, educational level, gender and handedness. Cerebral angiography, single-photon emission computed tomography (SPECT) and neuropsychological tests were performed approximately 1 week before and 3 weeks after CEA in all patients. In the patient group, the categories achieved in the new modified Wisconsin Card Sorting Test (WCST) improved significantly after CEA (4.0 +/- 2.0; before CEA: 2.3 +/- 2.1, p < 0.01). The perseverative errors of Nelson in the WCST improved significantly (before CEA: 9.1 +/- 6.9, after CEA: 3.3 +/- 3.4, p < 0.01). The difficulty maintaining set in the WCST improved significantly (before CEA: 2.3 +/- 1.9, after CEA: 1.3 +/- 1.7, p < 0.05). In the control group, none of the test scores showed significant improvement between the first and second tests. Moreover, frontal lobe function improved significantly in those patients with baseline carotid artery diameter of more than 70% of normal, or whose preoperative cerebral perfusion reserve was reduced by less than 15% of a response to acetazolamide. Our results suggest that CEA improves frontal lobe function in patients with severe carotid stenosis or reduced cerebral perfusion reserve.