Asymptomatic carotid stenosis and cognitive impairment

INTRODUCTION: The aim of this review was to assess the evidence supporting an association between asymptomatic carotid stenosis (ACS) with impaired cognitive function due to chronic cerebral hypoperfusion and/or silent cerebral embolization. EVIDENCE ACQUISITION: PubMed/Medline, Embase and the Cochrane databases were searched up to December 1, 2022 to identify studies focusing on the association between ACS and cognitive function, as well as the mechanisms involved. EVIDENCE SYNTHESIS: A total of 49 studies were identified. The evidence supports an association between ACS and progressive cognitive deterioration. The mechanisms involved in the cognitive decline associated with ACS include cerebral hypoperfusion and silent cerebral embolization. Irrespective of the mechanism involved, severe ACS is associated with a progressive decline in several aspects of cognitive function, including global cognition, memory and executive function. CONCLUSIONS: Patients with ACS are at increased risk of developing a progressive decline in their cognitive function. The evidence from the present systematic review suggests that it may be inappropriate to consider ACS patients developing cognitive dysfunction as “asymptomatic”. Besides stroke, myocardial infarction and death rates, future studies should include evaluation of cognitive function as part of their outcomes.