Sleep disorder may be sign of dementia

ROCHESTER, N.Y., July 29 (UPI) -- A sleep disorder may signal dementia or Parkinson's disease up to 50 years before diagnosis, U.S. researchers said.

Researchers at the Mayo Clinic in Rochester, Minn., found an average span of 25 years between the start of the sleep disorder and the symptoms of dementia in 13 study participants, a diagnosis of Parkinson's disease in another 13 participants and in one participant a diagnosis of multiple system atrophy -- a disorder that causes symptoms similar to Parkinson's disease.

The study, published in Neurology, found the 27 people had experienced rapid eye movement sleep behavior disorder for at least 15 years before developing one of the three neurologic conditions. REM sleep behavior disorder is characterized by "acting out" dreams, including violent movements such as punching.

"More research is needed on this possible link so that scientists may be able to develop therapies that would slow down or stop the progression of these disorders years before the symptoms of Parkinson's disease or dementia appear," study author Dr. Bradley Boeve said in a statement.