Diagnostic Criteria 327.42 (647.52)
A. Repeated episodes of arousal during sleep associated with vocalization and/or com- plex motor behaviors.
B. These behaviors arise during rapid eye movement (REM) sleep and therefore usually occur more than 90 minutes after sleep onset, are more frequent during the later por- tions of the sleep period, and uncommonly occur during daytime naps.
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.
6. Coexisting mental and medical disorders do not explain the episodes.
The essential feature of rapid eye movement (REM) sleep behavior disorder is repeated episodes of arousal, often associated with vocalizations and / or complex motor behaviors arising from REM sleep (Criterion A). These behaviors 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-filled, 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, thrusting, 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- will depend on a number of factors, including the frequency of events, the potential for vi- olence or injurious behaviors, embarrassment, and distress in other household members.
Severity determination is best made based on the nature or consequence of the behavior rather than simply on frequency. Although the behaviors are typically prominent and vi- olent, lesser behaviors may also occur.
The prevalence of REM sleep behavior disorder is approximately O.38%—0.5% in the gen- eral population. Prevalence in patients with psychiatric disorders may be greater, possibly related to medications prescribed for the psychiatric disorder.
The onset of REM sleep behavior disorder may be gradual or rapid, and the course is usu- ally progressive. REM sleep behavior disorder associated with neurodegenerative disor- ders may improve as the underlying neurodegenerative disorder progresses. Because of the very high association with the later appearance of an underlying neurodegenerative disorder, most notably one of the synucleinopathies (Parkinson’s disease, multiple system atrophy, or major or mild neurocognitive disorder with Lewy bodies), the neurological status of individuals with REM sleep behavior disorder should be closely monitored.
REM sleep behavior disorder overwhelmingly affects males older than 50 years, but in- creasingly this disorder is being identified in females and in younger individuals. Symp- toms in young individuals, particularly young females, should raise the possibility of narcolepsy or medication-induced REM sleep behavior disorder.
Genetic and physiological. Many widely prescribed medications, including tricyclic antidepressants, selective serotonin reuptake inhibitors, serotonin-norepinephrine reup- take inhibitors, and beta-blockers, may result in polysomnographic evidence of REM sleep without atonia and in frank REM sleep behavior disorder. It is not known whether the predisposition.