Background & Purpose
Cerebral infarcts increase the risk for cognitive impairment. The relevance of location and number of infarcts with respect to cognitive function is less clear.
We studied the cross-sectional association between number and location of infarcts and cognitive performance in 4030 non-demented participants of the Age Gene/Environment Susceptibility-Reykjavik Study. Composite scores for memory (MEM), processing speed (SP) and executive function (EF) were created from a neuropsychological battery. Subcortical, cortical, and cerebellar infarcts were identified on brain MRI. We performed linear-regression analyses adjusted for demographic and vascular risk factors, depression, white matter lesions, and atrophy.
Compared to participants with no infarcts, those with infarcts in multiple locations (n=287, 7%) had slower SP (β=-0.19, p<.001) and poorer MEM (β=-0.16, p<.001) and EF (β=-0.12, p=.003). Compared to no infarcts, the presence of either subcortical infarcts only (n=275) (β=-0.12, p=.016) or cortical infarcts only (n=215) (β=-0.17, p=.001) was associated with poorer MEM performance. Compared to no infarcts, a combination of cortical and subcortical infarcts (n=45) was associated with slower SP (β=-0.38, p<.001) and poorer EF (β=-0.22, p=.02), while a combination of cerebellar and subcortical infarcts (n=89) was associated with slower SP (β=-0.15, p=.04). Infarcts in all three locations was associated with slower SP (β=-0.33, p=.002).
Having infarcts in more than one location is associated with poor performance in memory, processing speed, and executive function, independent of cardiovascular comorbidities, white matter lesions and brain atrophy, suggesting that both the number and the distribution of infarcts jointly contribute to cognitive impairment.