408 Sleep-Wake Disorders
C. Upon awakening from these episodes, the individual is completely awake, alert, and
not confused or disoriented.
D. Either of the following: 
1. REM sleep without atonia on polysomnographic recording.
2. A history suggestive of REM sleep behavior disorder and an established synuclein-
opathy diagnosis (e.g., Parkinson’s disease, multiple system atrophy).
E. The behaviors cause clinically significant distress or impairment in social, occupa-
tional, or other important areas of functioning (which may include injury to self or the
bed partner).
F. The disturbance is not attributable to the physiological effects of a substance (e.g., a
drug of abuse, a medication) or another medical condition.
G. Coexisting mental and medical disorders do not explain the episodes.
Diagnostic Features
The essential feature of rapid eye movement (REM) sleep behavior disorder is repeated
episodes of arousal, often associated with vo calizations and/or complex motor behaviors
arising from REM sleep (Criterion A). These be haviors often reflect motor responses to the
content of action-filled or violent dreams of being attacked or trying to escape from a
threatening situation, which may be termed dream enacting behaviors. The vocalizations are
often loud, emotion-fill ed, and profane. These behaviors may be very bothersome to the
individual and the bed partner and may result in significant injury (e.g., falling, jumping,
or flying out of bed; running, punching, thru sting, hitting, or kicking). Upon awakening,
the individual is immediately awake, alert, and oriented (Criterion C) and is often able to
recall dream mentation, which closely correlates with the observed behavior. The eyes
typically remain closed during these events. The diagnosis of REM sleep behavior disor-
der requires clinically significant distress or  impairment (Criterion  E); this determination