Interesting results from a small and very preliminary study that was carried out by Benjamin Natelson et al in America to assess the use of vagal nerve stimulation as a possible form of treatment for people who have developed ME/CFS following COVID-19.
Whilst there are also reports of benefit from people in the UK who are using vagal nerve stimulation, these findings have to be regarded as very speculative rather than proven in our current state of knowledge.
Research into the use of vagal nerve stimulation is summarised and referenced in the MEA purple book.
8/14 patients fulfilled a priori criteria for improvement. Additionally, five patients, including four fulfilling criteria for successful improvement and one who did not show improvement, also showed reductions of at least 10 points on the POMS.
The study results suggested that non-invasive stimulation of the auricular branch of the vagus nerve of tVNS treatment is a possible therapeutic modality for treating long COVID. Though, it is possible that the positive result was simply a placebo response to treatment in the absence of a control group for comparison. Nevertheless, since at least a third of patients improved (57% improvement rate), it was a successful trial.
In this trial, researchers did not forbid the participants to take medications. They only asked them not to increase the current medication dosages or start new ones. Additionally, they measured more than one outcome measure, which reduced patient pool heterogeneity. Also, it helped them select patients with a broad set of symptoms at greater severity, including brain fog, fatigue, widespread pain, and post-exertional malaise. The authors plan to expand this study by adding a sham control limb to validate the efficacy of tVNS in treating long COVID. If such a trial would show tVNS efficacy, this will open up more possibilities for the treatment of those patients for whom specific treatment is currently unavailable.
Dr Charles Shepherd
Trustee and Hon. Medical Adviser. The ME Association.