Leaky blood vessels in the brain appear to be a driver of cognitive dysfunction in Alzheimer’s disease, a new study reports.
The research, published in Nature Medicine, followed 161 older adults for five years. The investigators at the University of Southern California (USC) in Los Angeles, USA, found that leaky blood vessels in the brain were the common denominator in the most severe cases of memory dysfunction, regardless of the presence of amyloid-β or tau – two proteins that have long been thought of as the main triggers in the development of Alzheimer’s.
Assessment of cognitive dysfunction was performed via a variety of cognitive tasks. The results were fed into a clinical dementia rating score, alongside contrast-enhanced magnetic resonance imaging and a novel cerebrospinal fluid biomarker to identify breakdown of the blood-brain barrier. Crucially, when the blood-brain barrier is impaired, usually in older brains, blood flow to neurons is diminished and there is the potential for damage.
While more research is needed to truly understand the link between the blood-brain barrier and Alzheimer’s, early assessment of the breakdown of the blood-brain barrier appears to be a powerful biomarker for cognitive dysfunction, independent of amyloid-β and tau.