Alzheimer's link to herpes virus in brain, say scientists

Brain scan of a patient with Alzheimer’s disease.The presence of viruses in the brain has been linked to Alzheimer’s disease in research that challenges conventional theories about the onset of dementia.The results, based on tests of brain tissue from nearly 1,000 people, found that two strains of herpes virus were far more abundant in the brains of those with early-stage Alzheimer’s than in healthy controls.