Gierthmuehlen et al. (2026)
- Authors: Mortimer Gierthmuehlen, Kirsten Schmieder, Niklas Thon, Petra Christine Gierthmuehlen, Nadine Höffken, Nina Timmesfeld
- Institutes: Department of Neurosurgery, Knappschaftskrankenhaus Bochum, Ruhr University Bochum, Germany, Department of Prosthetic Dentistry, University Medical Center Duesseldorf, Heinrich Heine University, Germany
- Publisher: Neurology and Therapy
- Link: DOI
Summary
This pilot trial demonstrates that transcutaneous auricular vagus nerve stimulation (taVNS) is a safe and feasible intervention with high patient adherence for those suffering from Long COVID. However, the study found that active stimulation was not more effective than a sham (placebo) treatment in reducing fatigue. These results suggest that while patients may experience subjective improvement, it cannot yet be definitively attributed to the electrical stimulation itself rather than a placebo effect.
What was researched?
The COVIVA trial investigated the safety, feasibility, and clinical efficacy of transcutaneous auricular vagus nerve stimulation (taVNS) for treating fatigue syndrome in patients with Long COVID.
Why was it researched?
Fatigue is a debilitating and common symptom of Long COVID with limited treatment options. Researchers hypothesized that non-invasive stimulation of the vagus nerve could modulate the autonomic and immune dysregulation thought to drive the condition.
How was it researched?
In this randomized, single-blinded pilot study, 45 patients were assigned to receive either sham stimulation, sub-threshold taVNS, or above-threshold taVNS. Participants used a CE-certified stimulation device for four hours daily over a period of four weeks, with researchers tracking adherence and changes in fatigue, mood, and quality of life.
What has been found?
The study reported high adherence, with participants averaging nearly four hours of device use per day. While fatigue and quality-of-life scores improved across all participants, there were no statistically significant differences between the active stimulation groups and the sham group. Adverse events were minor, consisting mainly of local skin irritation and mild vertigo.
Discussion
The findings suggest a strong potential for a placebo effect or natural recovery over the four-week period, as the sham group improved similarly to the active groups. The study’s limitations include its small sample size and the single-blinded design, which may have influenced participant reporting.
Conclusion & Future Work
Although taVNS was found to be safe and well-tolerated, it did not demonstrate superiority over sham treatment for Long COVID fatigue in this cohort. Future research with larger, more homogeneous populations and objective biological markers is necessary to determine if specific stimulation parameters might be effective.