Abstract: Objective To investigate the consistency of the sources of snoring sound induced by simulated snoring and drug-induced sleep endoscopy in simple snores(SS)and mild obstructive sleep apnea/hypopnea syndrome(OSAHS). Methods A total of 40 cases diagnosed as either SS or mild OSAHS by polysomnography(PSG)underwent simulated snoring and drug-induced sleep endoscopy successively. The vibration of soft tissue of upper airway was observed with fiberoptic laryngoscope. Results Under simulated snoring condition and drug-induced sleep endoscopy, there were different vibrations in the pharynx. The McNemar statistical results showed that there was no significant difference between simulated snoring and drug-induced sleep endoscopy in determining the vibration of soft palate and epiglottis/tongue base(P=0.774, 0.077), while there was very significant difference between the two methods in determining the vibration of the lateral phaynged wall(P=0.002). Under these two conditions, there was no significant difference in the incidence rates of vibration of both soft palate and epiglottis/tongue base(P=0.770, 0.110), while the incidence rate of vibration of lateral pharyngeal wall was much higer under drug-induced sleep endoscopy than that under simulated snoring(P=0.005). Conclusion Compared with drug-induced sleep endoscopy, simulated snoring is relatively reliable in determination of soft palate vibration, slightly inferior for epiglottis/tongue base, but is unreliable in the determination of lateral pharyngeal wall vibration.

Key words: Drug-induced sleep, Fiberoptic laryngoscope, Sleep apnea, obstructive, Snoring, Snoring sound