Postoperative somnolence in patients after carotid endarterectomy.

Eighty-one patients undergoing carotid endarterectomy were divided into two groups based on the degree of stenosis of the carotid artery. Group I, 37 patients, was defined as having severe carotid stenosis (greater than 70%). Group II, 44 patients, was defined as having mild (less than 40%) or moderate (40% to 70%) carotid artery stenosis. Both groups were evaluated for neurologic and psychologic changes in the postoperative period. Prospective analysis demonstrated no significant differences between groups I and II in the areas of cardiac disease, history of preoperative stroke, preoperative and postoperative hypertension, diabetes, or postoperative computed tomography changes. Group II had a significantly higher percentage of carotid artery ulceration (p less than 0.01). Postoperative analysis revealed 34 group I patients had 6 to 8 weeks of lethargy versus two group II patients (p less than 0.01). Eleven group I patients had headaches for the first week postoperatively versus three patients in group II (p less than 0.05). Four group I patients had paranoid ideation, and another four patients had clinical depression, but not one patient in group II (p less than 0.01) had these psychiatric disturbances. These data suggest that significant, reversible neurologic and psychologic changes can occur because of reperfusion after relief of severe stenosis of the carotid artery.