Which sleep disorder involves acting out dreams due to loss of REM atonia?

• A. REM Sleep Behavior Disorder
• B. Narcolepsy
• C. Sleep Apnea
• D. Insomnia

Answer: (A)

During REM sleep, the brain normally imposes a paralysis (REM atonia) that keeps you from acting out dreams. When this paralysis is lost or diminished, a person may physically move during REM sleep and enact their dreams. This pattern is the defining feature of REM Sleep Behavior Disorder, as dream enactment occurs precisely because REM atonia isn’t properly present. The result can include thrashing, punching, or kicking during sleep, and it can pose safety risks to the person and a bed partner. Other listed disorders present different problems—narcolepsy centers on daytime sleepiness and sudden sleep episodes (often with cataplexy), sleep apnea involves repeated breathing interruptions during sleep, and insomnia is trouble falling or staying asleep. A sleep study can show REM sleep without atonia, which supports the diagnosis, and treatment typically includes safety measures plus medications such as clonazepam or melatonin.