Parasomnias

Abstract

Parasomnias are frequent sleep disorders characterized by abnormal behaviors, physical events, or experiences occurring during different sleep stages. The International classification of sleep disorders subdivides the parasomnias into three subsets: (a) Disorders of Arousal encompassing non REM sleep-related disorders, namely Confusional arousals, Sleepwalking, and Sleep terrors (b) Parasomnia usually associated with REM sleep, enclosing REM sleep behavior disorders, Recurrent isolated sleep paralysis, and Nightmare disorder, and (c) other parasomnias; a wide and heterogeneous group of sleep-related disorders awaiting for a final nosographic allocation. Parasomnias often run in families and so there is probably a genetic factor in many cases. Brain disorders may be responsible for some parasomnias, such as many cases of REM sleep behavior disorder. Parasomnias may also be triggered by other sleep disorders such as obstructive sleep apnea, and by various medications. Due to their potential dangerous consequences, and the number of dramatic reports of serious damages to the sleeper or others they may be a theme of interest for forensic medicine.