Dream-enactment behavior possible predictor for dementia

Monday, August 28, 2006

SCOTTSDALE, Ariz. — Have you ever been told that you talk or act out dreams in your sleep? It could be dream-enactment behavior (DEB), a symptom of a sleep disorder called "REM Sleep Behavior Disorder" (RSBD). RSBD is a condition characterized by yelling, screaming, talking or movement of arms and legs during sleep in ways that mimic dream imagery.

While most of us mumble in our sleep at times, and toss about in bed, that is not usually true DEB. True DEB sleepers speak clearly and display pronounced limb movements that can sometimes lead to injury to themselves or their bed partner, and occurs in less than 1 percent of the population.

Now researchers at Mayo Clinic have identified DEB as a possible predictor for future development of a form of dementia called Dementia with Lewy Bodies (DLB). DLB combines features of Alzheimer's and Parkinson's disease and may be the second most common form of dementia (following Alzheimer's disease). Patients with DLB usually have RSBD, along with other defining symptoms: visual hallucinations, parkinsonism (characterized by loss of motor function) and memory loss.

A Mayo Clinic study was conducted in collaboration with Banner-Good Samaritan Medical Center that included 17 healthy adults, ages 47 to 68, who reported at least one parent or sibling with dementia. Participants and their sleep partners completed a questionnaire developed by the Mayo Clinic Sleep Disorders Clinic. Those with a history of DEB in the preceding 10 years were compared to a matched group who did not.

Preliminary evidence from the research found mildly altered brain activity in the group reporting DEB. This alteration resembled that known to occur in patients with DLB, and therefore suggests that DEB may be identifying a population at risk for dementia. Although there is still no known effective prevention for dementia, research into treatment possibilities continues around the world.

Researchers hope that one day, early intervention with treatment may delay the onset and progression of those at-risk for dementia.

"In many respects, the DEB brain-related changes have profound implications for early detection, tracking and possible prevention of dementia", said Richard J. Caselli, M.D., lead researcher of the DEB study and Chair of Neurology, Mayo Clinic in Arizona.

The study was published in the July 2006 issue of SLEEP.

Mayo Clinic is the first and largest integrated, not-for-profit group practice in the world. As a leading academic medical center in the Southwest, Mayo Clinic focuses on providing specialty and surgical care in more than 65 disciplines at its outpatient facility in north Scottsdale and at Mayo Clinic Hospital. The 208-licensed bed hospital is located at 56th Street and Mayo Boulevard (north of Bell Road) in northeast Phoenix, and provides inpatient care to support the medical and surgical specialties of the clinic, which is located at 134th Street and Shea Boulevard in Scottsdale.

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