Association between asymptomatic carotid stenosis and cognitive function: A systematic review

Asymptomatic carotid stenosis (CS), traditionally considered clinically silent, may be an independent risk factor for a cognitive impairment. To determine whether an association exists between asymptomatic CS and cognitive function, we systematically reviewed the literature in the Cochrane Library, MEDLINE, EMBASE and the China National Knowledge Infrastructure databases. A total of 8 cross-sectional studies and 2 community-based cohort studies were included, comprising 763 participants in the CS group and 6308 participants in the non-CS group. All but one study supported the association between asymptomatic CS and cognitive impairment. Pooled analysis identified older age (2 studies) and cerebral hypoperfusion (2 studies) as additional factors in patients with asymptomatic CS that may linked to cognitive decline. These results suggest that rather than being clinically silent, asymptomatic CS may be associated with cognitive impairment, and this should be further investigated in high-quality studies.