Sleep-related deglutition in patients with OSAHS under CPAP therapy.

Conclusion: Continuous positive airway pressure (CPAP) therapy improved not only apnea-hypopnea during sleep and sleep structure but also sleep-related deglutition, especially respiratory phase patterns associated with deglutition. Objectives: Sleep-related deglutition and related respiratory phase patterns in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) under CPAP therapy were investigated. Methods: Deglutition during sleep was examined in 10 patients who had severe OSAHS under CPAP therapy via time-matched recordings of polysomnography and surface electromyography. Results: The mean number of swallows per hour during the total sleep time was 1.6 ± 1.3. The mean period of the longest absence of deglutition was 66.4 ± 19.6 min. Deglutition was related to the sleep stage. The mean number of swallows per hour was 6.8 ± 8.4 during stage 1 sleep, 1.1 ± 0.8 during stage 2 sleep, 0.1 ± 0.4 during stage 3 sleep, and 0 during stage 4 sleep. The deeper the sleep stage, the lower the mean deglutition frequency. The mean number of swallows per hour was 0.8 ± 0.5 during REM sleep. Most deglutition occurred in association with spontaneous electroencephalographic arousal. Swallows followed by inspiration were markedly reduced. Under CPAP therapy, sleep-related deglutition and its respiratory phase pattern had normalized. [ABSTRACT FROM AUTHOR]