Clinical manifestations, forensic consequences, and treatment of violent parasomnias

Parasomnias are undesirable behaviors that occur during sleep. Some of these events can be violent and result in injuries to self or others, and some may even result in disability or death. There are no predictors to determine if a parasomnia will result in violence; hence, it is importance to learn to identify parasomnias in general and intervene when necessary. A detailed patient history is required to identify parasomnias. Video polysomnography is the recommended test to use, and additional electromyogram leads can be added to identify movement and correlate events with sleep or wakefulness. The polysomnogram is also helpful to determine presence of obstructive sleep apnea, which is a known precipitating factor for parasomnias. Other precipitating and predisposing factors are fragmented sleep, deprivation of sleep, alcohol, medications, disorders of sleep (eg, sleep apnea, restless legs syndrome, insomnia, narcolepsy), and environmental triggers such as sudden noise, flickering light, or bed partner’s snoring. Violent parasomnias that result in harm can be adjudicated to criminal courts, where investigation attempts to determine the presence of consciousness in the patient during the episode, indicating intent.