Violent parasomnias. forensic implications

Parasomnias are defined as unpleasant or undesirable behavioral or experiential phenomena that occur predominately or exclusively during the sleep period. Most parasomnias represent the simultaneous admixture of wakefulness and sleep. This chapter focuses on the clinical features, pathophysiology, diagnosis, and treatment of the two most common parasomnias: (1) disorders of arousal (confusional arousals, sleepwalking, and sleep terrors), which represent admixtures of wakefulness and nonrapid eye movement sleep; and (2) rapid eye movement (REM)-sleep behavior disorder (RBD), which is a manifestation of admixed wakefulness and REM sleep. Disorders of arousal are very common, perhaps part of the normal human condition, and are not the manifestation of underlying psychiatric disease. RBD is often the harbinger of degenerative neurological conditions, particularly the synucleinopathies (Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy); it is a frequent accompaniment of narcolepsy with cataplexy, and may be induced by numerous medications, particularly the selective serotonin reuptake inhibitors and the serotonin-norepinephrine reuptake inhibitors. Parasomnia behaviors underscore the fact that consciousness, being ever so evanescent, exists on a broad spectrum and is not an easily delineated dichotomous state. Such a dynamic understanding of consciousness has significant scientific, legal, and social implications raising interesting and difficult questions regarding awareness, responsibility, culpability, and even what it means to be human. Emphasis is placed upon the importance of the emerging field of Sleep Forensics in the evaluation of violent, injurious, or alleged criminal behaviors resulting from these parasomnias.