ABSTRACT
Objective@#To compare the changes of genioglossus electromyography (GGEMG) with and without continuous positive airway pressure (CPAP) ventilation in moderate to severe obstructive sleep apnea (OSA) patients.@*Methods@#Each of subjects, including male snorers and non-snorers, underwent polysomnography (PSG) with synchronous GGEMG recording with intra-oral bipolar silver ball electrodes at the Sleep Center of Beijing Tsinghua Changgung Hospital from August 2016 to Sepember 2017. Manual CPAP pressure titration and with GGEMG were performed in patients diagnosed moderate to severe OSA. T-test was used to compare the changes of GGEMG in OSA group (n=12, AHI (65.90+23.67) events/h) and control group (n=6, AHI(2.30+1.93) events/h) before and after CPAP treatment.@*Results@#Variables of GGEMG (including tonic, peak and phasic GGEMG) were higher in OSA group than in control group during both wakefulness and non rapid eye movement(NREM) sleep. However, with CPAP treatment, the GGEMG variables were significantly decreased in OSA group during NREM sleep(tonic GGEMG: 1.23%±0.73% vs. 2.54%±1.12%, t=4.024, P=0.002; peak GGEMG: 12.37%±13.19% vs. 26.98%±15.52%, t=2.795, P=0.017; phasic GGEMG: 3.81%±2.47% vs. 8.82%±3.84%, t=5.113, P<0.001).@*Conclusions@#CPAP treatment can eliminate respiratory events and maintain airway patency. It is helpful to normalize the excessive GGEMG response in OSA patients during sleep, which has therapeutic significance to alleviate and prevent genioglossal neuromuscular lesions.
ABSTRACT
Upper airway patency closely contact with neuromuscular airway regulation during respiratory, especially the activity of the pharyngeal dilators. The genioglossus is the largest pharyngeal dilators with its contraction playing the most important role in keeping the pharyngeal airway open. In healthy individuals, genioglossus activation shows a negative correlation with pharyngeal collapsibility and upper airway resistance. Negative pressure during inspiration can stimulate airway mechanoreceptors to produce a muscle reflex activity. However, in obstructive sleep apnea (OSA) patients, the muscles cannot always compensate for the increased mechanical load, resulting in frequent obstructive breathing events. A number of studies have shown that the collapsibility of upper airway during sleep in OSA patients is closely related to the activity of genioglossus electromyography(GGEMG). The present article describes the current understanding regarding the characters of GGEMG during sleep in healthy adults, as well as the pathophysiology of GGEMG in OSA patients.