Stimulation of Vagus Nerve Reduces Rhumatoid Arthritis Symptoms

According to science presented at EULAR 2019, electrostimulation of the vagus nerve—the longest, most complex of the 12 pairs of cranial nerves originating in the brain—could provide significant reductions in rheumatoid arthritis symptoms. 

“This is a really exciting development. For many patients suffering from rheumatoid arthritis, current treatments don’t work, or aren’t tolerated,” said Professor Thomas Dörner, chairperson of the Scientific Programme Committee, EULAR, in a press release. “These results open the door to a novel approach to treating not only rheumatoid arthritis, but other chronic inflammatory diseases. This is certainly an area for further study.”

“Vagas” comes from the latin word for “wandering” and per the press release, the vagus nerve wanders from the brain to organs in the neck, chest, and abdomen. Researchers explained that recent developments in mapping neurologic immune responses allowed this distinction to be discovered.

“In one of the circuits, the ‘inflammatory reflex’, signals are transmitted in the vagus nerve that inhibit the production of cytokines including tumor necrosis factor (TNF), an inflammatory molecule that is a major therapeutic target in rheumatoid arthritis,” explained the press release about the study. “It is thought that, by stimulating the activity of this inflammatory reflex, innate immune responses can be modulated without abolishing them or producing significant immunosuppression.”

The pilot study consisted of implanting a miniaturized neurostimulator called a MicroRegulator into 14 patients with rheumatoid arthritis who had already failed on at least two biologics or targeted oral therapies. Randomized into three groups, patients either received a placebo, stimulated once daily, or stimulated 4 times a day for 12 weeks. Results showed that two-thirds of participants who received stimulation once a day met EULAR good or moderate response criteria with a mean change of Disease Activity Score 28-joint count C reactive protein of -1.24 compared to a mean change of 0.16 in the placebo group.

Per the press release on the study, “cytokines, a broad and loose category of small proteins that are important in cell signaling, were also measured…with the actively stimulated groups showing a decrease of more than 30% in levels of IL 1β, IL-6, and TNF-α.” 

“Our pilot study suggests this novel MicroRegulator device is well-tolerated and reduces signs and symptoms of rheumatoid arthritis,” said Mark Genovese, MD, Stanford University, Stanford, CA, in a statement. “These data support the study of this device in a larger placebo-controlled study as a novel treatment approach for rheumatoid arthritis and possibly other chronic inflammatory diseases.”—Edan Stanley