Disrupted Sleep could be an early sign of Alzheimer's

Those who are suffering from the sleep disorders have a reason to worry as this could be an early warning sign of Alzheimer's disease, says scientists.

To reach at this conclusion the scientists worked on a mouse model. Researchers from the Washington University School of Medicine in St. Louis, observed that when the first signs of Alzheimer's plaques appear in the brain, the normal sleep-wake cycle is disturbed to an extent.

"If sleep abnormalities begin this early in the course of human Alzheimer's disease, those changes could provide us with an easily detectable sign of pathology," senior study author David M. Holtzman, professor and head of neurology at Washington, the journal Science Translational Medicine has been reported saying.

"As we start to treat Alzheimer's patients before the onset of dementia, the presence or absence of sleep problems may be a rapid indicator of whether the new treatments are succeeding," Holtzman said.

Holtzman's lab was among the first to establish a link between sleep problems and Alzheimer's through studies of sleep in mice genetically altered to develop Alzheimer's plaques as they age, says a university statement.

Formerly in a 2009 study, he showed that brain levels of a primary component of the plaques naturally increases when healthy young mice are awake and drop after they go to sleep. Keeping mice awake disrupted this cycle and accelerated the development of brain plaques.

Co-author Randall Bateman, professor of neurology at Washington University found a similar a similar rising and falling of the plaque component, a protein called amyloid beta, in the cerebrospinal fluid of healthy humans.

The research led by Jee Hoon Roh, neurologist and postdoctoral fellow in Holtzman's lab, reveals that when the first indicators of brain plaques noticed, the natural changes in amyloid beta levels stop in both mice and humans.

The mice are active in night as these are nocturnal animals

Mice are nocturnal animals and normally sleep for 40 minutes during every hour of daylight, but when Alzheimer's plaques began forming in their brains, their average sleep times reduced to 30 minutes per hour.

--with inputs from IANS