Globally, Obstructive Sleep Apnoea affects nearly 1 billion people, with significant numbers found in regions such as the UK and the US. This condition, marked by intermittent breathing interruptions during sleep, does more than merely disturb restful slumbers.
Sleep Apnoea and Its Health Implications
Obstructive Sleep Apnoea is more than the main culprit behind loud snoring. It leads to recurrent pauses breathing due to obstructions of the airway when asleep, causing diminished oxygen intake. Consequently, sufferers experience fragmented sleep with poor sleep quality, daytime sleepiness, lack of concentration and poor memory, elevated levels of anxiety and depression. With heightened risks ranging from headaches to road traffic accidents and even cardiovascular issues, hypertension and stroke, there’s a clear need for affected individuals, especially those severely impacted, to seek evidence-based treatment.
Traditional Treatment Paradigms
Besides postural advice, weight control, avoidance of alcohol and smoking, as well as lifestyle advice evidence based treatment is available. Since the 1980’s, several treatment modalities have been introduced to offset the effects of Obstructive Sleep Apnoea. Continuous Positive Airway Pressure (CPAP) remains the most notable solution. By continuously supplying pressurised air through a mask, it keeps the airway open during sleep. However, ensuring consistent use by patients remains challenging, with good usage rates dropping from 75% after three months of therapy to just 25% by year five. Alternative measures such as mandibular advancement devices (MAD), bilevel positive airway pressure and surgical options may provide good treatment effects as well.
Unveiling the TESLA HOME Trial: A Leap Forward in Sleep Medicine
Non-CPAP therapy in sleep medicine has been revolutionised by exploring electrical stimulation of the upper airway dilators as a potential treatment for Obstructive Sleep Apnoea (OSA) over the last decade1. The key techniques include invasive Hypoglossal Nerve Stimulation (HNS), requiring surgery with an implant, and the simpler, non-invasive Transcutaneous Electrical Stimulation in patients with OSA (TESLA).1
The TESLA investigators sought to investigate the applicability of a transcutaneous electrical neurostimulator (TENS machine) as a simpler solution. In a pivotal randomised controlled trial by Pengo et al in 2016,2 the investigators could prove that the loss of neuromuscular tone in the upper airway dilator muscles during sleep could be improved by the application of transcutaneous electrical stimulation during sleep. Their research, involving 36 participants who stayed for the study in the sleep laboratory, underscored the efficacy of transcutaneous electrical stimulation in responders, primarily those with a slimmer neck, lower body mass index, and an apnoea hypopnoea index (AHI) up to 35 events per hour, identifying mild-to-moderate cases of OSA. Almost half of participants in that trial responded positively, highlighting the treatment’s potential.
Subsequent research led to the development of the protocol for the TESLA home trial, which sought to evaluate this treatment in a domestic setting for at least three months, with specific focus on the previously identified responder group. Under the leadership of Drs Steier and Ratneswaran, on behalf of the TESLA investigator group, the current TESLA home trial randomised 56 participants, probing the practicality and effectiveness of domiciliary, at-home TESLA. The study was conducted in collaboration with King’s College London and Guy’s and St Thomas’ NHS Foundation Trust.
TENS: A Promising Treatment for OSA
The team’s innovative approach concentrated on the upper airway, the hypoglossal nerve and the genioglossus muscle. They positioned patches beneath the chin, optimising electrical stimulation for the best therapeutic effect, and observed the response using ultrasound. The electrical stimulation was achieved using a TENS machine, more commonly associated with pain relief.
Their research, recently published in The Lancet E-Clinical Medicine3, has provided substantial evidence on the potential of this treatment, particularly when employed under controlled conditions, with supervision, patient selection and education.
All patients, recruited between June 2018 and February 2023, were diagnosed with OSA and had documented challenges adhering to CPAP therapy. Two distinct groups emerged from this pool: one subjected to the TENS therapy (TESLA, intervention) and the other continued with their regular CPAP regimen (usual care). The groups were comparably matched in terms of age, gender, and body mass index (BMI). After 3 months, the TESLA therapy group showcased a notable decrease in their apnoea-hypopnoea-index (AHI). The unadjusted difference in ΔAHI between the two groups was -11.5 per hour (p = 0.016). When adjusted for baseline values, the difference narrowed to ΔAHI -7.0 h per hour, still favouring the TESLA therapy, though the statistical significance was reduced (p = 0.12). However, the 4% oxygen desaturation index (ODI) and the Epworth Sleepiness Scale (ESS) improved significantly as well when compared to usual care. Only minor adverse effects were reported, with one participant experiencing mild headaches linked to the treatment.
The results shed light on the therapy’s potential efficacy and set the stage for a more comprehensive multi-centre trial.
The TESLA Home trial introduces a novel non-CPAP treatment for patients with OSA who are struggling with their CPAP usage. Despite these promising findings more research is needed to establish standardisation of the therapy and evaluate health economical data. Until then a cautious interpretation of these results is important. To this end, the doctors released a statement on the charity webpage hope2sleep.co.uk.
- Ratneswaran, Deeban, Ahmad Guni, Martino F. Pengo, Miral Al-Sherif, Baiting He, Michael CF Cheng, Joerg Steier, and Esther I. Schwarz. “Electrical stimulation as a therapeutic approach in obstructive sleep apnea—a meta-analysis.” Sleep and breathing 25 (2021): 207-218.
- Pengo, Martino F., Sichang Xiao, Culadeeban Ratneswaran, Kate Reed, Nimish Shah, Tao Chen, Abdel Douiri et al. “Randomised sham-controlled trial of transcutaneous electrical stimulation in obstructive sleep apnoea.” Thorax 71, no. 10 (2016): 923-931.
- Deeban Ratneswaran, Michael Cheng, Ebrahim Nasser, Rajiv Madula, Martino Pengo, Kath Hope, Yuanming Luo, Georgios Kaltsakas, Michael I. Polkey, John Moxham, Joerg Steier. 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