Severe cerebral amyloid angiopathy characterizes an underestimated variant of vascular dementia

Cerebral amyloid angiopathy (CAA) is a frequent finding on neuropathological examination of patients with Alzheimer's disease (AD). A recent study from our laboratory showed that CAA also frequently occurred in vascular dementia with additional mild Alzheimer encephalopathy (VaD-ae, i.e. Alzheimer pathology that does not fulfill criteria for AD). Because CAA is associated with cerebral hemorrhages and infarctions, it is of significant interest to confirm or dismiss the hypothesis that CAA contributes clinically in the many patients that present with VaD-ae. Therefore, we examined entire temporal lobes of 11 VaD-ae cases and 11 age-matched AD cases with Abeta immunohistochemistry. Six of 11 VaD-ae cases had severe CAA, more extensive than in any AD case. There was a trend toward more cortical infarctions in this group, indicating that CAA in VaD may be of clinical importance and an underestimated cause of dementia.