Impact of carotid endarterectomy upon cognitive functioning - A systematicreview of the literature

Background and Purpose: The extent to which carotid endarterectomy (CEA) in fluences cognitive functioning has been the subject of a number of studies often with conflicting conclusions. This paper systematically reviews the l iterature in an attempt to clarify this issue. Results: Although the majori ty of studies (16/28) reported an improvement in cognition after surgery, a substantial minority (12/28) found no change. Studies before 1984 tended t o report an improvement, while later studies tended to report no change in cognition. Cognitive improvement was also more likely the longer the time i nterval between CEA and assessment. The studies were found to differ on man y methodological factors, e.g. sample size, type of patient and control gro up, severity and side of carotid stenosis, the range of cognitive tests and timing of postoperative assessment. Conclusion: Given the conflicting find ings, and the methodological issues, it is not possible to draw a clear con clusion regarding the impact of carotid endarterectomy upon cognition. Futu re research which pays attention to these methodological factors is needed in order to adequately resolve the current debate.