Noninvasive Nerve Stimulator May Ease Sleep Apnea

— Intervention recipients saw apnea, oxygen desaturation, sleepiness scores improve

MedicalToday
A photo of a transcutaneous electrical neurostimulator device.

Using a transcutaneous electrical neurostimulator (TENS) machine may reduce the severity of obstructive sleep apnea (OSA) in people not adhering to continuous positive airway pressure (CPAP) therapy, a small single-center randomized trial suggested.

After 3 months, the difference in apnea/hypopnea index (AHI) scores in unadjusted analysis significantly favored the TENS group versus the usual-care group -- where patients were encouraged to continue using their CPAP -- but that advantage lost significance after adjustment for baseline values:

  • Unadjusted AHI: −11.5 events per hour (95% CI -20.7 to -2.3, P=0.016)
  • Adjusted AHI: -7.0 events per hour (95% CI -15.7 to 1.8, P=0.12)

Oxygen desaturation index (ODI) dropped by an adjusted 8.3 events per hour with TENS therapy (P=0.036), and scores on the Epworth Sleepiness Scale (ESS) also saw an adjusted change of -2.6 points (P=0.020), reported Joerg Steier, MD, of King's College London, and coauthors.

Adverse events related to the study were only seen in one TENS patient, who experienced headaches and was advised to stop treatment, according to the phase III trial published in .

Steier and colleagues reported that people in the intervention treatment group used their TENS device for an average of 4 days per week for 4.5 hours each night, while those in the usual-care group averaged zero hours of use of their CPAPs per night.

"Our results confirm that it remains challenging to motivate patients to use CPAP therapy once they have failed to adhere to this first-line therapy of OSA. However, it also highlights the willingness of patients to try emerging non-CPAP therapies that may provide therapeutic benefits (e.g., symptom control) beyond usual care," the group wrote.

"In this context, and considering all the evidence across the clinical outcomes measured in this trial, it is very likely that the intervention is effective for patients with OSA," they concluded.

While CPAP is a widely used method to treat OSA, adherence to treatment can be impacted by a number of factors.

"Not all patients with obstructive sleep apnea are able to use CPAP therapy, often because the mask can be uncomfortable and in severe cases can lead to sleep deprivation. Alternatives for CPAP include mandibular advancement devices, and sometimes surgical options like hypoglossal nerve stimulation (HNS) which requires a pre-assessment, surgical implantation, activation, and follow-up appointments," explained Steier in a .

He noted that TENS may become a potential cheap, non-invasive option for those looking to avoid CPAP.

TENS therapy is often used as a pain management method, utilizing lower-level electrical currents to stimulate nerves and provide relief. TENS is sometimes used as a treatment for pain from injuries, arthritis, menstrual periods, and fibromyalgia, among other causes.

In the so-called , those receiving intervention treatment used a TENS/EMS Premier Combo Plus device made by Everyway Medical Instruments. Following patient education, nightly usage was recorded for a median of 3 months. Nerve stimulation was delivered by submental hydrogel patches attached to the machine.

Controls were instead encouraged to continue to use their CPAP devices and received an educational session.

A total of 56 OSA patients were included in the single-center, open-label study, all failing to use CPAP therapy for at least 4 hours per night at baseline. There were 29 patients receiving intervention and 27 receiving usual care following randomization.

Patients had an average age of 59 years, about two-thirds were men, 57% were white, and average BMI was just over 28. Patients in the control group had an AHI of 14.4 events per hour at baseline, while those in the intervention group had an AHI of 24 events per hour.

Data were collected from June 6, 2018 to February 7, 2023. Median follow-up was 3 months.

One major limitation to the study is that the follow-up period of the study was significantly impacted as a result of COVID-19 pandemic lockdowns. The trial was paused in March 2020, but later a protocol amendment incorporated infection prevention and control guidance.

"Despite pandemic-related limitations of the amended protocol this trial provides the evidence that TESLA [transcutaneous electrical stimulation] improves clinically meaningful outcomes over the observed follow up period, and the transcutaneous approach is likely to offer an affordable alternative for responders to electrical stimulation in clinical practice," the authors nevertheless concluded.

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    Elizabeth Short is a staff writer for . She often covers pulmonology and allergy & immunology.

Disclosures

This study was supported by funding from the British Lung Foundation and the United Kingdom Clinical Research Collaboration.

Steier is the named inventor on a patent for a snoring and sleep apnea device that is owned by his employing organizations, Guy's & St. Thomas' NHS Foundation Trust/King's College London. A coauthor reported a relationship with Phillips Respironics.

Primary Source

eClinicalMedicine

Ratneswaran D, et al "Domiciliary transcutaneous electrical stimulation in patients with obstructive sleep apnoea and limited adherence to continuous positive airway pressure therapy: a single-centre, open-label, randomised, controlled phase III trial" EClinicalMedicine 2023; DOI: 10.1016/j.eclinm.2023.102112.