REM Sleep Parasomnias and REM Behavior Disorder: Clinical Features, Diagnosis, and Management

Parasomnias are unexpected and undesirable motor activities during sleep. Parasomnias may occur during non-rapid eye movement (NREM) sleep or rapid eye movement (REM) sleep. Nightmare disorder, recurrent isolated sleep paralysis, sleep -related hallucinations, REM behavior disorder (RBD), and status dissociatus (agrypnia excitata) are some of the REM parasomnias. Parasomnia overlap syndrome is a term used for parasomnias that occur in both REM and NREM sleep stages, such as catathrenia. RBD is a parasomnia that occurs during REM sleep stage and is characterized by acting out dreams (oneirism), leading to unwanted motor actions such as kicking, punching, or slapping, or sudden abrupt movements that can cause unexplained injuries to self or bedpartner. Memory of the associated dream is usually preserved. Diagnosis is obtained via video polysomnography with findings of REM activity without atonia and video recording of the oneirism. Treatment starts with developing a safety plan, improving sleep hygiene, and identifying any medications or other triggers such as snoring or leg movements. Melatonin, benzodiazepines, and a few other medications are used for treatment of RBD and other REM parasomnias.