Postoperative Somnolence in Patients after Carotid Endarterectomy

 

INVESTIGATIONS CONCERNING NEUROLOGIC CHANGES after carotid endarterectomy have usually focused on the all-or-none aspect of either cerebrovascular accident or cranial nerve dysfunction. Recent studies, however, have investigated more subtle pathologic changes in mental status associated with carotid endarterectomy. Carotid endarterectomy on the severely stenotic carotid artery lesion results in a marked increase in blood flow to the ipsilateral cerebral hemisphere, which can result in a cerebral hyperperfusion syndrome. The mental status changes (somnolence) include a marked increase in postoperative lethargy, increases in psychiatric complaints including paranoid ideation and clinical depression, and increased frequency and severity of headaches. These symptoms usually revsolve after 6 to 8 weeks; however, some severe cases have progressed to seizures, intracerebral hemorrhage, and death. This study was designed as a prospective evaluation of severe carotid artery stenosis. Two groups of patients were selected on the basis of the severity of stenosis. All other preoperative risk factors were comparable between the two groups. The patients received a general psychologic and neurologic assessment preoperatively and again postoperatively. It was the purpose of this study to determine if significant reversible mental status changes are associated with carotid endarterectomy of the severely stenotic carotid artery lesion.

Preoperatively all patients underwent both arteriography and duplex scanning and were divided into two groups based on the severity of .tenosis of the carotid artery. Group I consisted of 37 patients classified as having severe carotid artery stenosis (range, 70% to 99% mean, 86% ± 8%) and comprised 23 men and 14 women, whose ages ranged irom 55 to 76 years (mean 64.6± 6.3). Group II consisted of 44 patients classified as having mild-to-moderate carotid artery stenosis (mild, 10% to 39%,34 patients; moderate, 40% to 70%, 10 patients; mean, 30% ± 11%) and comprised 26 men and 18 women, whose age. ranged from 58 to 76 year. (mean, 66.7 ± 5.8). The indications for carotid endarterectomy were (I) a transient ischemic attack, (2) an...