Chapter 53 - REM sleep parasomnias

Abstract

This chapter focuses on sleep behavior disorder (RBD). Rapid eye movement (REM) sleep parasomnias are disorders in which undesirable physical phenomena occur predominantly during REM sleep. REM parasomnias encompass abnormal sleep-related movements, behavior, emotions, and dreaming. Three conditions are commonly identified as REM sleep parasomnias, namely REM sleep behavior disorder (RBD), recurrent isolated sleep paralysis, and nightmare disorder. RBD is accompanied by electromyographic (EMG) abnormalities in REM sleep, consisting of excess muscle tone and/or phasic EMG activity. Behaviors can range from simple motor activities such as laughing, talking, shouting, or excessive body and limb jerking to complex behavior such as gesturing, punching, kicking, sitting up, leaping from bed, and running. A characteristic feature of RBD is the occurrence of specific and somewhat stereotyped dream content irrespective of individual psychological profiles. Another polygraphic characteristic of RBD is the presence of periodic leg movements in sleep (PLMS). RBD is divided into primary and secondary forms.