Deglutition and respiratory patterns during sleep in the aged.

CONCLUSION

Deglutition was extremely infrequent and displayed unique patterns during sleep in the aged.

OBJECTIVES

The deglutition and respiratory phase patterns during sleep in the healthy aged were investigated in this study.

METHODS

Ten aged adults (average age = 71 years) were examined via time-matched digital recordings of polysomnography and surface electromyography of the muscles (thyrohyoid and suprahyoid muscles) related to swallowing.

RESULTS

During sleep, swallowing was extremely infrequent and absent for long periods in the aged. The median number of swallows per hour during total sleep time was 0.6, and the median longest deglutition-free period was 134.8 minutes. Most deglutition occurred in association with spontaneous electroencephalographic arousal both in REM and non-REM sleep. Deglutition was related to the sleep stage. The deeper the sleep stage, the lower the mean deglutition frequency. There was no deglutition during deep sleep. Overall muscle tone is inhibited during REM sleep. However, deglutition also occurred in association with spontaneous EEG arousal. The deeper the sleep stage, the lower the mean arousal frequency, and the lower the mean ratio of arousal with deglutition to arousal. Approximately one-third of swallows occurred after inspiration and were followed by inspiration.