Amyloid Aggregation in the Brain as a Driver of White Matter Hyperintensities

A white matter hyperintensity is a small areas of tissue damage in the brain, such as results from rupture of a small blood vessel and consequent bleeding. These areas of damage are readily visible in MRI scans, and their prevalence is known to correlate with loss of cognitive function and rising dementia risk. Here, researchers provide evidence to suggest that this process is primarily the result of amyloid-β aggregation in the brain rather than vascular aging processes. Bright spots called white-matter hyperintensities (WMHs) often appear on MRI scans of people with familial or sporadic Alzheimer's disease (AD), and they tend to intensify as the disease progresses. Some scientists think they reflect cerebrovascular disease. However, researchers now offer a different explanation. They reported that WMHs worsened most in people with extensive neurodegeneration, amyloid plaques, or cerebral microbleeds, a sign of cerebral amyloid angiopathy (CAA), while WMH severity did not correlate with vascular risk. They concluded that WMHs are driven by AD pathology. Researchers compared the total volume of WMHs to cardiovascular risk, as measured by the Framingham Heart Study cardiovascular disease risk score, and to the amount of amyloid, be it plaques or CAA. Researchers drew data from clinical records and almost 4,000 brain scans of 1,141 people from three longitudinal cohorts: the Harvard Aging Brain Study, the Alzheimer's Disease Neuroimaging Initiative, and the Dom...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs