Prevalence of cerebral vascular amyloid-β deposition and stroke in an aging Australian population: A postmortem study

Cerebral amyloid angiopathy (CAA) is a putative risk factor for lobar cerebral haemorrhage and infarction in the elderly. However, the prevalence of stroke in a population with CAA is not known. Amyloid-β immunohistochemistry was used to assess CAA prevalence as a function of age, and the relationship between CAA and stroke in 100 individuals aged 50–91 years who died unexpectedly and had a Coroner’s postmortem. Blocks were taken from several cortical areas and from areas of infarction or haemorrhage. Parenchymal Aβ was first found in the 6th decade, whereas vascular Aβ did not appear until the 7th decade. The prevalence of both vascular and parenchymal Aβ increased with age to a maximum in the 9th decade. The age at onset of vascular Aβ deposition was similar to that in an English study of CAA but a decade later than in Japanese studies. There was no association between the presence of vascular Aβ and cerebral haemorrhage or infarction. The findings indicate differences in the time-course of vascular and parenchymal Aβ deposition with age, as well as racial differences. The lack of association between vascular Aβ and cerebral haemorrhage or infarction indicates that, in the present population, CAA was usually asymptomatic