Thrashing and flailing during sleep might be a warning sign of future disease or dementia
People who kick and lash out while fast asleep in bed face a high risk of developing Parkinson’s disease and certain forms of dementia, scientists report online December 24 in Neurology.
The condition, called rapid-eye-movement sleep behavior disorder, results when a person’s muscles fail to relax during sleep. “During REM sleep, with the most vivid dreaming, mostly we’re paralyzed,” says neurologist Ronald Postuma of McGill University in Montreal. “The brain shuts off muscle tone. We want to run but we can’t.”
But in people with REM sleep behavior disorder, muscle tone isn’t shut down. “As a consequence, you act out your dreams,” he says. People with the condition have been known to break a hand on a wall, hurt a spouse or fall out of bed, he says.