Alzheimer's Disease Annihilates the Brain Cells That Keep Us Awake, Scientists Believe

A study in Alzheimer's and Dementia found Alzheimer's kills a network of brain cells that keeps people awake, reports Newsweek . This may explain why some people feel sleepy during the day years before they receive an Alzheimer's diagnosis. The researchers learned that the tau protein had built up in three brain regions that help people stay awake in deceased subjects with Alzheimer's, and 75 percent of neurons in those areas were gone. Investigation of the brains of seven people with two other forms of dementia — progressive supranuclear palsy and corticobasal disease — did not find damage in those regions, suggesting Alzheimer's may have a unique impact on the brain. "Our study shows that . . . the daytime sleepiness is a primary event caused by degeneration of the wake-promoting neurons rather than a reaction to the fragmented sleep, and as such, the treatment should be different," said University of California, San Francisco Professor Lea Grinberg.