Severely enlarged brain vessel spaces predicted bleeding lesions

An observational analysis studied 932 older adults who tested positive for amyloid, a protein, but had no cognitive impairment or bleeding-related brain lesions. Their average age was 71.7 years. Researchers used data from the Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease randomised trial. They assessed enlargement of fluid-filled spaces around brain vessels in the centrum semiovale, an area beneath the brain's outer layer.

Over a median 5.1 years, participants with severe enlargement were more likely to develop their first lesions related to cerebral amyloid angiopathy, a condition in which amyloid builds up in brain blood vessel walls. The lesions were small bleeds in the brain's lobes or iron deposits on its surface left by bleeding. Severe enlargement was not associated with early cognitive differences. Participants who developed lesions showed more pronounced cognitive decline.