Nighttime Movements May Predict Later Risk of Dementia and Parkinson's Disease

Individuals who kick or cry out during their sleep may be at increased risk of developing dementia or Parkinson's disease later in life, according to a recent study published in the journal Neurology.

This sleep disorder, known as REM sleep behavior disorder (RSBD), involves a failure to inhibit muscle tone during REM (or dream) sleep. This may allow an individual to act out his or her dreams, including activities such as punching, kicking, or crying out.

The study examined 93 people with RSBD who had no signs of other neurodegenerative disease. They were followed over 5 years. More than 1 in 4 developed neurodegenerative diseases, including 14 with Parkinson's disease, 11 with dementia, and one with a rare disorder called multiple system atrophy. The estimated five-year risk of developing a neurodegenerative disease was 18 percent, with the 10-year risk at 41 percent and the 12-year risk at 52 percent.

In individuals with RSBD, it may be useful to monitor for development of these other diseases so that early treatment can be started.

Reference

Postuma, R.B. et al. “Quantifying the risk of neurodegenerative disease in idiopathic REM sleep behavior disorder.” Neurology: December 24, 2008.