Noninvasive Vagus Nerve Stimulation Tolerated, Effective for Rheumatoid Arthritis

By Lisa Rapaport

March 22, 2021

(Reuters Health) - Non-invasive vagus nerve stimulation is safe and effective as an intervention for rheumatoid arthritis, a small proof-of-concept study suggests.

The study enrolled 35 patients with active rheumatoid arthritis and an inadequate response to therapy with disease modifying antirheumatic drugs (DMARDs). All DMARDS were discontinued 4 weeks prior to the trial. For the study, all participants were asked to wear a non-invasive vagus nerve stimulation device for up to 30 minutes daily over the course of 12 weeks.

Participants had follow-up visits at weeks 1, 2, 4, 8, and 12; the primary endpoint was mean change in the Disease Activity Score of 28 joints with C-reactive protein (DAS28-CRP) from baseline to week 12.

The mean DAS28-CRP score was 1.4 points lower at week 12 than at baseline, when mean scores were 5.3, the study team reports in The Lancet Rheumatology. Eleven out of 30 participants (37%) had mean scores of 3.2 or less at the end of the study, and seven patients (23%) had mean scores below 2.6.

"The aim of non-invasive vagus nerve stimulation is to modulate a neurological pathway that helps control immune function," said lead author Dr. Sara Marsal, head of rheumatology at Vall d'Hebron University Hospital and an associate professor of rheumatology at the Autonomous University of Barcelona.

"In our clinical trial, this resulted in meaningful clinical improvement for patients that had failed conventional DMARDs," Dr. Marsal said by email.

Overall, patients wore the device as directed on 94% of the study days. A total of 27 patients completed the study.

There were four adverse events, including one superficial skin abrasion at the point of contact where the device touched the ear. The other three events didn't appear to be related to the device, and no patients dropped out of the study due to side effects.

Two main limitations of the study are the small sample size and the open-label design, the authors note.

The results need to be reproduced in a larger group over a longer period of time using a placebo group and including patients refractory to pharmacological therapy, said Alexandre Kanashiro of the department of neuroscience and behavior at Ribeirao Preto Medical School, University of Sao Paulo, in Brazil.

If additional studies do confirm the safety and effectiveness of this intervention, then "the use of this non-invasive technology would be really encouraging for the treatment of rheumatoid arthritis and other chronic inflammatory conditions," Kanashiro, who wasn't involved in the study, said by email.

"The long-term side-effects of so many of our therapeutic drugs can be severe and life-threatening, so using our body's built-in immune system and boosting it a bit with bioelectronics may be the best possible way to treat inflammation-related disease," said Christopher Wilson, a professor of basic sciences and pediatrics at the Loma Linda University School of Medicine in California.

"Vagus nerve stimulation has the advantage of using the body's own immune system to rebalance the immune response and, to the best of our knowledge so far, can be used to increase anti-inflammatory reflexes and decrease pro-inflammatory responses," Wilson, who wasn't involved in the study, said by email.

SOURCE: and The Lancet Rheumatology, online February 1, 2021.