linguistic:paraphrasing
Muscle

Lack of REM atonia causes REM behavior disorder, those affected physically act out their dreams, or conversely "dream out their acts", under an alternative theory on the relationship between muscle impulses during REM and associated mental imagery (which would also apply to people without the condition, except that commands to their muscles are suppressed). This is different from conventional sleepwalking, which takes place during slow-wave sleep, not REM. Narcolepsy, by contrast, seems to involve excessive and unwanted REM atonia: cataplexy and excessive daytime sleepiness while awake, hypnagogic hallucinations before entering slow-wave sleep, or sleep paralysis while waking. Other psychiatric disorders including depression have been linked to disproportionate REM sleep. Patients with suspected sleep disorders are typically evaluated by polysomnogram.