Rheumatoid arthritis patients receiving stimulation of the vagus nerve showed "robust" responses in a recent study, researchers report.

Implanting a device to stimulate the vagus nerve helped patients improve significantly during a recent study conducted at the Feinstein Institute for Medical Research.

Rheumatoid arthritis is an autoimmune disease characterized by the immune system attacking the joints. Although the cause of the condition is unknown, the goal of treatment is to stop inflammation, which relieves symptoms, prevents worse damage and reduces long-term complications.

Researchers at the University of AmsterdamFeinstein Institute for Medical Research and SetPoint Medicaltested whether stimulating the inflammatory reflex directly, using an implanted device, could reduce symptoms.

While it had worked before in studies with animals, the method's success in the recent small study suggests it could be effective for humans -- and that the concept may be useful for other inflammatory diseases.

"This is a real breakthrough in our ability to help people suffering from inflammatory diseases," Dr. Kevin Tracey, president and CEO of the Feinstein Institute for Medical Research, said in a press release. "While we've previously studied animal models of inflammation, until now we had no proof that electrical stimulation of the vagus nerve can indeed inhibit cytokine production and reduce disease severity in humans. I believe this study will change the way we see modern medicine, helping us understand that our nerves can, with a little help, make the drugs that we need to help our body heal itself."

For the study, published in the Proceedings of the National Academy of Sciences, the researchers implanted a stimulation device on the vagus nerve in 17 patients, activating and deactivating it on a set schedule for 84 days, measuring progress and response at 42 days.

Patient response to the device was measured using the DAS28-CRP, a disease activity composite score that measures tender and swollen joints, serum C-reactive protein levels and the assessment of disease activity by patient and doctor.

No serious side effects were found in any patient, and many who had failed to respond to previous treatment showed significant improvement, including the inhibition of TNF production, which can significantly affect the severity of rheumatoid arthritis.

The researchers say more studies are required on the treatment, but that if it continues to be effective the method may pay dividends beyond arthritis and be useful for patients with inflammatory diseases such as Crohn's, Parkinson's and Alzheimer's.

"Our findings suggest a new approach to fighting diseases with bioelectronic medicines, which use electrical pulses to treat diseases currently treated with potent and relatively expensive drugs," said Anthony Arnold, chief executive officer of SetPoint Medical. "These results support our ongoing development of bioelectronic medicines designed to improve the lives of people suffering from chronic inflammatory diseases and give healthcare providers new and potentially safer treatment alternatives at a much lower total cost for the healthcare system."