Cerebral amyloid angiopathy and cortical microinfarcts as putative substrates of vascular dementia

Abstract

Vascular dementia (VaD) has occasionally been associated with cerebral amyloid angiopathy (CAA), but the prevalence and significance of this counterintuitive relationship are poorly known. Therefore, we investigated the presence and characteristics of CAA in brains of VaD cases. We examined temporal and parietal regions of the cerebral cortex of 26 consecutive VaD cases from the Lund Longitudinal Dementia Study. We carried out immunohistochemistry and routine stainings, determined Apolipoprotein E (ApoE) genotypes, and obtained clinical characteristics on the studied group for retrospective analysis. CAA was marked in eight out of 26 cases, and correlated strongly with the presence of cortical microinfarcts, both in the temporal lobe and in the parietal lobe. Based on comparisons with eight age-matched VaD cases without CAA, the clinical records suggested that VaD cases with CAA as a group exhibited less pronounced neurological symptoms. A clear contribution of the ApoE genotype could not be identified. Based on a combination of the clinical and pathological data, we suggest that microinfarcts in the cerebral cortex associated with severe CAA may be the primary pathological substrate in a significant proportion of VaD cases. Future studies should be undertaken to confirm or dismiss the hypothesis that these cases exhibit a different symptom profile than VaD cases without CAA.