muscle atonia

The near-complete paralysis of skeletal muscles during rapid eye movement (REM) sleep. This state, also called REM atonia, is essential for preventing the physical enactment of dreams. While some localized twitching may occur, overall muscle tone is significantly reduced. REM sleep is the only sleep phase requiring all animals to undergo muscle atonia, one feature distinguishing it from non-REM sleep stages. Disorders such as REM behavior disorder and narcolepsy are linked to disruptions in this mechanism