title: Continuous transcutaneous submental electrical stimulation in obstructive sleep apnea: a feasibility study.
abstract: 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/m(2)) 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 H(2)O to 19.7 (7.1) cm H(2)O (P = .022), increasing to 24.2 (10.8) cm H(2)O 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.
authors: King's College London School of Medicine, King's Health Partners, London, England. Electronic address: joerg.steier@kcl.ac.uk.
authors: Joerg
authors: J
authors: Steier
authors: King's College London School of Medicine, King's Health Partners, London, England.
authors: John
authors: J
authors: Seymour
authors: King's College London School of Medicine, King's Health Partners, London, England.
authors: Gerrard F
authors: GF
authors: Rafferty
authors: King's College London School of Medicine, King's Health Partners, London, England.
authors: Caroline J
authors: CJ
authors: Jolley
authors: King's College Hospital, London, England.
authors: Eskinder
authors: E
authors: Solomon
authors: The State Key Laboratory of Respiratory Disease, Guangzhou Medical School, Guangzhou, China.
authors: Yuanming
authors: Y
authors: Luo
authors: NIHR Respiratory Biomedical Research Unit, Royal Brompton Hospital and Imperial College, London, England.
authors: William D-C
authors: WD
authors: Man
authors: NIHR Respiratory Biomedical Research Unit, Royal Brompton Hospital and Imperial College, London, England.
authors: Michael I
authors: MI
authors: Polkey
authors: King's College London School of Medicine, King's Health Partners, London, England.
authors: John
authors: J
authors: Moxham
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D017286:Polysomnography; D012123:Pulmonary Ventilation / Q000502:physiology; D012891:Sleep Apnea Syndromes / Q000503:physiopathology*; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology* / Q000628:therapy; D014059:Tongue / Q000000981:diagnostic imaging / Q000503:physiopathology; D004561:Transcutaneous Electric Nerve Stimulation / Q000379:methods*; D014463:Ultrasonography