Sleep disorder linked to dementia

People with a sleep disorder who kick or cry out during sleep may be at greater risk for developing dementia, says a study from the University of Montreal.

People who suffer from REM sleep behavior disorder have excessive muscle tone during sleep, which causes them to punch, kick or cry out as they essentially act out their dreams, said the study published Wednesday in the online issue of Neurology.

The study followed 93 people for an average of five years who had this sleep disorder but showed no signs in the beginning of a neurodegenerative disease such as dementia or Parkinson’s.

During the study, 14 people developed Parkinson’s disease, 11 developed dementia and one person developed multiple system atrophy, a rare disorder that affects movement, said Dr. Ronald B. Postuma, the study’s lead author.

The results suggest an opportunity for protecting against the progression to disease, perhaps even preventing it before the symptoms can appear, Postuma said.