The lethargy that many Alzheimer’s patients experience is caused not by a lack of sleep but rather by the degeneration of a type of neuron that keeps us awake, according to a study that also confirms the tau protein is behind that neurodegeneration.
The study’s findings contradict the common notion that Alzheimer’s patients sleep during the day to make up for a bad night of sleep and point toward potential therapies to help these patients feel more awake.
The data came from 85 study participants who were patients at the University of California San Francisco’s Memory and Aging Center and volunteered to have their sleep monitored with an electroencephalogram, and then donated their brains after they died. A full 33 patients had been diagnosed with Alzheimer’s disease. Twenty were diagnosed with progressive supranuclear palsy (PSP), which damages the neurons that make patients feel tired, so these patients are unable to sleep and become sleep deprived. In addition, researchers examined 32 volunteers who had healthy brains through the end of life.
“We were able to prove what our previous research had been pointing to – that in Alzheimer’s patients who need to nap all the time, the disease has damaged the neurons that keep them awake,” said Lea T. Grinberg, M.D., Ph.D., a neuropathologist and senior author on the study. “It’s not that these patients are tired during the day because they didn’t sleep at night. It’s that the system in their brain that would keep them awake is gone.”
Full findings appear in JAMA Neurology.
