SLEEP BRUXISM AS A MANIFESTATION OF SUBCLINICAL RAPID EYE-MOVEMENT SLEEP BEHAVIOR DISORDER

A 59-year-old man with temporomandibular joint pain/dysfunction syndro me presented with a long history of nocturnal bruxism. All-night polys omnographic recordings with video monitoring showed episodes of teeth grinding or clenching occurring exclusively during rapid eye movement (REM) sleep, which were often associated with movements of the hands a nd fingers and/or brief vocalization. Throughout REM sleep, there was excessive phasic chin electromyographic twitching, without increased t one, and also excessive phasic electromyographic twitching in multiple muscle sites. The patient maintained a normal nonrapid eye movement-R EM cycle, but showed increased REM density. Polysomnographic character istics suggested that there may be a common pathophysiology in a certa in type of sleep bruxism and the REM sleep behavior disorder. Sleep br uxism seen in this case is concluded to be a manifestation of subclini cal REM sleep behavior disorder.