Study of 500000 Medical Records Links Viruses to Alzheimer's Again And Again - ScienceAlert
A study of around 500,000 medical records has suggested that severe viral infections like encephalitis and pneumonia increase the risk of neurodegenerative diseases like Parkinson's and Alzheimer's.
People treated for a type of inflammation of the brain called viral encephalitis were 31 times more likely to develop Alzheimer's disease.Around 80 percent of the viruses implicated in brain diseases were considered 'neurotrophic', which means they could cross the blood-brain barrier."After reading [this] study, we realized that for years scientists had been searching – one-by-one – for links between an individual neurodegenerative disorder and a specific virus," said senior author Michael Nalls, a neurogeneticist at the National Institute on Aging in the US.While this retrospective observational study cannot demonstrate a causal link, it adds to the pile of research hinting at the role of viruses in Parkinson's and Alzheimer's disease."Our results support the idea that viral infections and related inflammation in the nervous system may be common – and possibly avoidable – risk factors for these types of disorders."