How Seniors' Sleep Patterns Affect the Brain

Poor quality sleep in the elderly may affect the brain

(RxWiki News) Older people need sleep just like younger folks. The National Sleep Foundation notes, however, that the elderly are more likely to have trouble falling asleep and staying asleep, and that may be a problem.

New research from Canada found that poor-quality sleep in the elderly was tied to blood vessel problems in the brain. The brains of elderly people examined after death showed arteriosclerosis (hardening of the arteries) and areas where tissue had been starved of oxygen.

Lead researcher Andrew Lim, MD, said in a press release, "The forms of brain injury that we observed are important because they may not only contribute to the risk of stroke but also to chronic progressive cognitive and motor impairment.”

Dr. Lim is an assistant professor of neurology at the University of Toronto, Canada, and a neurologist and scientist at Sunnybrook Health Sciences Center in Toronto.

Dr. Lim and colleagues examined the brains of 315 people who had undergone a minimum of one full week of sleep monitoring prior to death.

Most of the study patients were women, with an average age of 90. Twenty-nine patients had had a stroke, while 61 percent showed signs of blood vessel damage in the brain.

The sleep monitoring showed an average of almost seven arousals an hour. An arousal occurs when an individual moves from a deep sleep stage to a lighter stage, and interrupts the sleep pattern. Repeated arousals can cause fragmented sleep.

People who showed increased sleep fragmentation had 27 percent higher odds of having severe arteriosclerosis. As arousals increased, so did the signs of oxygen deprivation, which can damage brain cells.

Dr. Lim noted that this study doesn't establish cause and effect. Further research is needed.

"However, there are several ways to view these findings: sleep fragmentation may impair the circulation of blood to the brain, poor circulation of blood to the brain may cause sleep fragmentation, or both may be caused by another underlying risk factor,” Dr. Lim said.

This article was published online in the January issue of the American Heart Association journal, Stroke.

The National Institutes of Health, Canada's Heart and Stroke Foundation and the Canadian Institutes of Health Research funded this study. The authors disclosed no conflicts of interest.

Review Date: 
January 13, 2016