Parasomnias and Abnormal Sleep-Related Movements

Abstract Parasomnias are undesirable physical phenomena or behavior that develop during the sleep period. These abnormal events or experiences are not principally abnormalities of the states of sleep and wakefulness, and they are not generally associated with major complaints of excessive sleepiness or insomnia. Parasomnias can manifest as activation of skeletal muscles or the autonomic nervous system during sleep. They usually occur intermittently or episodically either within sleep or during its transition to and from wakefulness. Occasionally, parasomnias may give rise to violent and potentially injurious behavior. Parasomnias can be classified into three groups based on the American Academy of Sleep Medicine International Classification of Sleep Disorders (ICSD; second edition; see References) (Box 7–1). 1. Disorders of arousal from non–rapid eye movement (NREM) sleep, including confusional arousals, sleepwalking, and sleep terrors 2. Parasomnias usually associated with rapid eye movement (REM) sleep, including REM sleep behavior disorder (including parasomnia overlap disorder and status dissociatus), recurrent isolated sleep paralysis, and nightmare disorder 3. Other parasomnias, including sleep-related dissociative disorder, sleep enuresis, sleep-related groaning (catathrenia), exploding head syndrome, sleep-related hallucinations, and sleep-related eating disorder.