Parasomnias

Abstract

Parasomnias have long been recognized as part of sleep-related disorders or diseases in the mental disorders classification system such as Diagnostic and Statistical Manual of Mental Disorders. Nevertheless, many parasomnia symptoms are considered as a transient deviation from the norm in otherwise normal subjects due to disrupted status of consciousness. Sleep states are classified as rapid eye movement (REM) sleep and non-REM (NREM) sleep; similarly, parasomnias are classified as NREM-related parasomnias and REM-related parasomnias. NREM-related parasomnias share common pathophysiology of arousal-related phenomenon out of slow-wave sleep. Although listed as REM parasomnia disorders, nightmares and sleep paralysis are still considered comorbid symptoms or signs of other sleep disorders or mental disorders. Only REM sleep behavior disorder (RBD) is considered a relatively homogenous disease entity among all parasomnia diagnoses. Although RBD is the most newly added disorder entity in parasomnias, it is the most rigorously studied parasomnia such as RBD is strongly and clearly associated with concomitant or future developing neurodegenerative disease. This review contains 1 figure, 4 tables, and 18 references. Key Words: confusional arousals, dream enactment, pseudo-RBD, REM sleep behavior disorder, sleep-related eating, sleep terror, sleepwalking