A TONGUE RETAINING DEVICE AND SLEEP-STATE GENIOGLOSSUS MUSCLE-ACTIVITY IN PATIENTS WITH OBSTRUCTIVE SLEEP-APNEA

To define the effect of a tongue retaining device (TRD) on genioglossu s (GG) muscle activity in seven obstructive sleep apnea subjects, two overnight sleep studies were carried out with two TRDs. TRD-A had no a nterior bulb and incorporated two electrodes to record GG electromyogr aphic (EMG) activity. TRD-B had a bulb and it had electrodes similar t o those in TRD-A. Episodes of apnea/hypopnea (AH) were analyzed during both rapid eye movement (REM) and non-HEM (NREM) sleep. The peak GG m uscle activity was measured for the breath immediately before the AH ( pre-AH), for the first (first-E) and last (last-E) inspiratory efforts during the AH, and for the first breath after the AH (post-AH). The t ime lag between the peak GG EMG activity and the maximum inspiratory e ffort was calculated. The AH index decreased with both TRDs. The peak GG EMG activity preceded the maximum inspiratory effort throughout the periods, however the time lag changed considerably with TRD-A. The ti me lags with TRD-A and TRD-B differed significantly for the first-E an d the last-E during NREM sleep and for the first-E during REM sleep. T he TRD reduces AH severity, normalizes the time lag, and counteracts f luctuating GG EMG activity observed when no bulb is present.