Category Archives: REM behavior disorder

REM Behavior Disorder, a Parasomnia

What are Parasomnias?

In sleep medicine we define parasomnias as ‘undesirable events that accompany sleep.’ What makes these disorders so interesting is that they can involve more complex and apparently purposeful behaviors than other disorders of sleep. There are parasomnias that occur in REM sleep, and some in nonREM. Last post about Sleepwalking was one example, here’s another.

REM Sleep Behavior Disorder

During REM sleep your muscles are usually inhibited so that you don’t move during dreams. In this disorder, however, muscle tone is maintained, so the person ends up acting out their dreams. For an unknown reason the dreams that are acted out are usually unpleasant, action-filled and violent. The eyes usually remain closed, and people have been known to sit up, leap from bed, shout, swear, grab, flail their arms, punch, kick, and talk. As you can imagine, sleep-related injury is common for both the patient and their bedpartner. This disorder is more common among men over aged 50, and among those with a neurological disorder such as Parkinson’s disease. If you suspect REM Sleep Behavior Disorder then consult with a sleep clinic.

These are just two of the many types of parasomnias that people can experience. Feel free to email me with questions about other abnormal sleep behaviors if you wish.