Sleep-related violence: does the polysomnogram help establish the diagnosis?

With the growing number of legal cases of sleep-related violence coming to public attention, and the development of sleep medicine as an area of expertise, sleep clinicians are being turned to for help in discriminating those violent individuals who sustain a diagnosis of adult parasomnia of the arousal disorder type, (sleep walking, 307.46-0, sleep terrors 307.46-1, or confusional arousals 307.46-2) according to the International Classification of Sleep Disorders (The International Classification of Sleep Disorders: revised: diagnostic and coding manual. Rochester MN, American Sleep Disorders Association, 1997) from those whose episode of violence may have been carried out with full waking consciousness, or as the result of an impairment of judgement due to some psychiatric or neurological disorder. Clearly there is need to refine the diagnostic characteristics to resolve some of the contradictory descriptions of this disorder in the present literature. There is also the question whether the classical overnight polysomnogram is helpful in making this differential diagnosis, and if so, how should it be done to be maximally useful and what other testing is indicated.