Electrical stimulation as a therapeutic approach in obstructive sleep apnea - a meta-analysis.

PURPOSE: Electrical stimulation of the upper airway dilator muscles is an emerging treatment for obstructive sleep apnea (OSA). Invasive hypoglossal nerve stimulation (HNS) has been accepted as treatment alternative to continuous positive airway pressure (CPAP) for selected patients, while transcutaneous electrical stimulation (TES) of the upper airway is being investigated as non-invasive alternative. METHODS: A meta-analysis (CRD42017074674) on the effects of both HNS and TES on the apnea-hypopnea index (AHI) and the Epworth Sleepiness Scale (ESS) in OSA was conducted including published evidence up to May 2018. Random-effects models were used. Heterogeneity and between-study variance were assessed by I2 and τ2, respectively. RESULTS: Of 41 identified clinical trials, 20 interventional trials (n = 895) could be pooled in a meta-analysis (15 HNS [n = 808], 5 TES [n = 87]). Middle-aged (mean ± SD 56.9 ± 5.5 years) and overweight (body mass index 29.1 ± 1.5 kg/m2) patients with severe OSA (AHI 37.5 ± 7.0/h) were followed-up for 6.9 ± 4.0 months (HNS) and 0.2 ± 0.4 months (TES), respectively. The AHI improved by - 24.9 h-1 [95%CI - 28.5, - 21.2] in HNS (χ2 79%, I2 82%) and by - 16.5 h-1 [95%CI - 25.1, - 7.8] in TES (χ2 7%, I2 43%; both p < 0.001). The ESS was reduced by - 5.0 (95%CI - 5.9, - 4.1) (p < 0.001). CONCLUSION: Both invasive and transcutaneous electrical stimulation reduce OSA severity by a clinically relevant margin. HNS results in a clinically relevant improvement of symptoms. While HNS represents an invasive treatment for selected patients with moderate to severe OSA, TES should be further investigated as potential non-invasive approach for OSA.

Electrical stimulation for the treatment of obstructive sleep apnoea: a review of the evidence.

INTRODUCTION: Obstructive sleep apnoea is an increasingly prevalent clinical condition with significant impact on individuals and public health. Continuous positive airway pressure therapy is the standard treatment, but adherence is limited and alternative treatments are needed. In this context, non-invasive and invasive methods for the electrical stimulation of upper airway dilator muscles have been demonstrated to be effective in selected patients. Areas covered: This review will cover investigations on the clinical effects, safety, and tolerability of non-invasive and invasive electrical stimulation of the upper airway for the management of obstructive sleep apnoea. Following a search of the relevant literature published on PubMed this review is focused mainly on data obtained from randomized clinical trials and clinical studies. Expert commentary: The available evidence provides a rationale to consider upper airway electrical stimulation as treatment for selected patients with obstructive sleep apnoea, who have poor adherence or experience difficulties with continuous positive airway pressure therapy. Non-invasive stimulation using transcutaneous electrodes and implantable hypoglossal nerve stimulator technologies may provide an alternative to continuous positive airway pressure for the treatment of obstructive sleep apnoea via restoration of neuromuscular tone and improved upper airway patency.

Randomised sham-controlled trial of transcutaneous electrical stimulation in obstructive sleep apnoea.

INTRODUCTION: Obstructive sleep apnoea (OSA) is characterised by a loss of neuromuscular tone of the upper airway dilator muscles while asleep. This study investigated the effectiveness of transcutaneous electrical stimulation in patients with OSA. PATIENTS AND METHODS: This was a randomised, sham-controlled crossover trial using transcutaneous electrical stimulation of the upper airway dilator muscles in patients with confirmed OSA. Patients were randomly assigned to one night of sham stimulation and one night of active treatment. The primary outcome was the 4% oxygen desaturation index, responders were defined as patients with a reduction >25% in the oxygen desaturation index when compared with sham stimulation and/or with an index <5/hour in the active treatment night. RESULTS: In 36 patients (age mean 50.8 (SD 11.2) years, male/female 30/6, body mass index median 29.6 (IQR 26.9-34.9) kg/m(2), Epworth Sleepiness Scale 10.5 (4.6) points, oxygen desaturation index median 25.7 (16.0-49.1)/hour, apnoea-hypopnoea index median 28.1 (19.0-57.0)/hour) the primary outcome measure improved when comparing sham stimulation (median 26.9 (17.5-39.5)/hour) with active treatment (median 19.5 (11.6-40.0)/hour; p=0.026), a modest reduction of the mean by 4.1 (95% CI -0.6 to 8.9)/hour. Secondary outcome parameters of patients' perception indicated that stimulation was well tolerated. Responders (47.2%) were predominantly from the mild-to-moderate OSA category. In this subgroup, the oxygen desaturation index was reduced by 10.0 (95% CI 3.9 to 16.0)/hour (p<0.001) and the apnoea-hypopnoea index was reduced by 9.1 (95% CI 2.0 to 16.2)/hour (p=0.004). CONCLUSION: Transcutaneous electrical stimulation of the pharyngeal dilators during a single night in patients with OSA improves upper airway obstruction and is well tolerated. TRIAL REGISTRATION NUMBER: NCT01661712.