Myoelectric characteristics of tensor palatini and collapsibility of upper airway in OSA patients with different phenotypes under DISE.

Objective This study aims to evaluate the combination of myoelectric characteristics of tensor palatini muscle (TP) and collapsibility of upper airway in obstructive sleep apnea (OSA) patients with different external phenotypes of collapse pattern at velum level under drug-induced sleep endoscopy (DISE). Study design Case series with planned data collection. Setting Operation room. Subjects and methods 36 mainly collapse pattern at velum level OSA subjects underwent DISE with synchronous tensor palatini electromyograms (TP EMG), and polysomnography (ALICE 6). According to the phenotype of collapse pattern at velum level in DISE, the subjects were divided into group 1 (concentric collapse), group 2 (anteroposterior collapse), and group 3 (lateral collapse). Each group consisted of 13, 14, and 9 subjects, respectively, and was observed the electromyographic indexes at awake, sleep onset, during apnea and the third respiratory cycle after apnea. The active and passive upper airway critical closing pressure (Pcrit) of each group were measured at the same time, and the difference of neuromuscular response between different groups was evaluated. Results In tonic TPEMG, group 1 showed the highest value during awake and sleep onset, while group 2 was the highest during apnea and after apnea. In peak TPEMG, group 1 showed the highest value during awake. Group 2 showed the highest value during other states. In passive Pcrit and D value (difference between passive Pcrit and active Pcrit), group 2 was the highest, while group 1 was the highest in active Pcrit. Difference was statistically significant. Conclusions Under different states of awake, sleep onset, apnea and after apnea, the response force of tensor palatini muscle of OSA subjects with different phenotypes under DISE was different. Group 1 showed the highest EMG values only when awake and sleep onset, and it was most prone to collapse. Group 2 had the highest anatomical load (passive Pcrit) and the highest neuromuscular compensatory effect (D value).