Parasomnias.

This article presents four examples of parasomnia activity. Sleepwalking, sleep terror, and rhythmic movement disorder all occur more commonly in children; however, they can persist into adulthood. REM behavior disorder frequently occurs in elderly patients with neurologic lesions. The sleep stage associations of the different disorders differ. Two of the disorders, sleepwalking and sleep terrors, have a clear association with stage 3/4 sleep, and REM behavior disorder occurs in REM sleep. Rhythmic movement disorder episodes can present solely in REM sleep but more typically occur in light non-REM sleep, and there are usually voluntary episodes during wakefulness.