Effect of wake‐sleep transitions and rapid eye movement sleep on pharyngeal muscle response to negative pressure in humans
SA Shea, JK Edwards, DP White - The Journal of physiology, 1999 - Wiley Online Library
SA Shea, JK Edwards, DP White
The Journal of physiology, 1999•Wiley Online Library1 Genioglossus (GG) activation in response to upper airway negative pressure may be an
important mechanism in the maintenance of airway patency. This reflex occurs during
wakefulness but is diminished during stable non‐rapid eye movement (NREM) sleep. Since
obstructive events occur more commonly at wake‐sleep transitions and during rapid eye
movement (REM) sleep than during stable NREM sleep, we assessed the GG reflex during
these two vulnerable states. 2 Seventeen healthy adults were studied throughout one …
important mechanism in the maintenance of airway patency. This reflex occurs during
wakefulness but is diminished during stable non‐rapid eye movement (NREM) sleep. Since
obstructive events occur more commonly at wake‐sleep transitions and during rapid eye
movement (REM) sleep than during stable NREM sleep, we assessed the GG reflex during
these two vulnerable states. 2 Seventeen healthy adults were studied throughout one …
- 1Genioglossus (GG) activation in response to upper airway negative pressure may be an important mechanism in the maintenance of airway patency. This reflex occurs during wakefulness but is diminished during stable non‐rapid eye movement (NREM) sleep. Since obstructive events occur more commonly at wake‐sleep transitions and during rapid eye movement (REM) sleep than during stable NREM sleep, we assessed the GG reflex during these two vulnerable states.
- 2Seventeen healthy adults were studied throughout one evening and overnight. Electroencephalograms (EEGs), electro‐oculograms (EOGs), submental electromyogram (EMG), GG EMG (intramuscular electrodes), and choanal plus epiglottic pressures were recorded. The GG reflex response to pulses of −8 cmH2O choanal pressure applied via nose mask during early inspiration was quantified repeatedly during relaxed wakefulness, within five breaths of wake‐sleep transition (EEG alpha‐theta transition) and during REM sleep. Only trials without EEG arousal were analysed, resulting in data from 14 subjects during sleep onset and 10 subjects during REM sleep (overall, 174–491 trials per state).
- 3During wakefulness there was brisk GG reflex activation in response to negative pressure (amplitude: +78.5 ± 28.3 % baseline (mean ± s.e.m.); latency to maximal response: 177 ± 16 ms).
- 4At sleep onset, although there was marked variability among individuals, there was no significant reduction in the magnitude of the GG reflex for the group as a whole (amplitude: +33.2 ± 8.2 % baseline; latency: 159 ± 15 ms).
- 5In contrast, during REM sleep there was a reduction of GG reflex (amplitude: −12.6 ± 8.3 % baseline (P= 0.017vs. awake); latency: 160 ± 10 ms (n.s. vs. awake)) and greater airway collapsibility during the applied pressures (P= 0.043vs. awake).
- 6We conclude that there was no systematic reduction in the GG reflex to negative pressure at sleep onset. Nonetheless, it remains possible that sleep‐deprived normal subjects and patients with sleep apnoea could react differently.
- 7The apparent inhibition of the GG reflex during REM sleep may help explain why the upper airway is vulnerable to collapse during this state.
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