Changes In Heart Rate Associated With Rhythmic Masticatory Muscle Activities And Limb Movements In Patients With Sleep Bruxism

Background:Most sleep bruxism(SB)episodes occur with a companion of limb movements(LMs),and sympathetic tone increases before SB episodes.Study objectives:To characterize changes in heart rate(HR)in relation to rhythmic masticatory muscle activities(RMMA)and LMs in the SB patients.Methods:Polysomnographic recordings were carried out on 9 SB patients and 10normal controls.The amplitude and duration of HR increases,and time,velocity and maximum slope to reach HR peak associated with RMMA/LMs and duration of movement events were determined and their relationships with types of movements,masseter activities and levels of arousal were analyzed.Results:Among the HR increase events,50.83%started before and 49.17%initiated after the onset of RMMA/LMs in the SB patients and 50.60%started before and49.40%initiated after the onset of RMMA/LMs in the controls.The duration of RMMA/LMs was positively correlated with the amplitude and duration of HR increases,and time to reach HR peak(SB patients:r~2=0.14-0.88,P<0.0001;Controls:r~2=0.20-0.74,P<0.0001)as well as negatively correlated with the velocity of HR increases(SB patients:r~2=0.058,P<0.0001;Controls:r~2=0.13,P<0.0001).Two way ANOVA analyses showed significant differences in all the parameters except the maximum slope between types of movements(i.e.,RMMA,RMMA+LMs,and LMs;P<0.001),between types of masseter activities(i.e.,tonic,phasic,and mixed type;P<0.05-0.001)and between levels of arousal(P<0.001).Conclusions:These data suggest the HR increases are associated with types of movements,masseter activities and changes in levels of arousal.