Continuous Transcutaneous Submental Electrical Stimulation in Obstructive Sleep Apnea A Feasibility Study

Background: The therapeutic value of transcutaneous electrical stimulation of the genioglossus muscle in patients with obstructive sleep apnea (OSA) to reduce sleep-disordered breathing is unclear. Methods: Contraction of the genioglossus muscles during transcutaneous stimulation was investigated using ultrasonography in 11 healthy subjects (seven men, mean [SD] age 30 [6] years; BMI, 24.2 [3.5] kg/m(2)). Esophageal and gastric pressures were measured with balloon catheters, and transesophageal diaphragm electromyogram (EMGdi) was recorded during polysomnography in 11 patients with OSA (eight men, aged 51 [16] years; BMI, 42.0 [9.7] kg/m2) while transcutaneous electrical stimulation of the genioglossus was applied in non-rapid eye movement sleep (stage N2). Results: Ultrasonography measurements showed a significant increase in tongue diameter during stimulation (sagittal: 10.0% [2.8%]; coronal: 9.4 % [3.7%]). The measurements were reproducible and repeatable. In patients with OSA, snoring decreased during stimulation (P<.001) and oxygenation improved (P=.001); the respiratory disturbance index (RDI) fell from 28.1 (26.3) to 10.2 (10.2) events per hour during stimulation (P=.002), returning to 26.6 (26.0) events per hour after stimulation was stopped. Transdiaphragmatic pressure swing decreased from 24.1 (13.5) cm H2O to 19.7 (7.1) cm H2O (P=.022), increasing to 24.2 (10.8) cm H2O afterward, and EMGdi fell from 23.8% max (12.6% max) to 15.7% max (6.4% max) (P<.001), rising to 22.6% max (10.4% max) post stimulation. Conclusions: Continuous transcutaneous electrical stimulation of the genioglossus contracts the genioglossus muscle and reduces ventilatory load and neural respiratory drive in patients with OSA. CHEST 2011; 140(4):998-1007