Violent somnambulism: a parasomnia of young men with stereotyped dream-like experiences.

OBJECTIVE To characterize a subgroup of arousal parasomnias associated with violent behavior in adults. DESIGN A pilot study on clinical and polysomnographic data of 13 adult patients seen in a tertiary sleep center for the suspicion of arousal parasomnia associated with violence. RESULTS Nine young patients (8 males 1 female) had a common pattern of abnormalities: similar 'claustrophobic' dream-like experiences and complex, vehement dream enactments; no REM sleep without atonia on polysomnography. We call this syndrome 'violent somnambulism'. The rest of the patients had alcoholic delirium, partial epilepsy, possible REM sleep behavior disorder and a single sleep walking episode provoked by a sleeping pill. CONCLUSIONS AND HYPOTHESIS Sleep related violence needs thorough diagnostic evaluation for preventing life-threatening consequences. Violent somnambulism appears to be a distinct NREM sleep-related overlap parasomnia.