Ultrasound Therapy for Arthritis

While ultrasound has been widely used as an imaging tool for decades, recently neuroscientists have begun looking at using it to stimulate nerves for the treatment of inflammatory diseases such as rheumatoid arthritis.

The research grew out of past work in which the vagus nerve – a bundle of fibers that connects with the immune system – was stimulated in order to encourage the circulation of immune cells throughout the body. However, this approach requires surgically implanting electrodes. In two new animal studies, the researchers targeted a main branch of the vagus nerve which passes through the spleen. When this area was stimulated with ultrasonic waves, the result appeared to be equally effective as direct stimulation of the vagus nerve.

In the first study on rats, inflammatory response to an injected toxin was diminished after only a few minutes of ultrasound treatment to the splenic nerve. In the second study, it was found that stimulating the splenic nerve for 20 minutes per day over the course of a week reduced arthritis symptoms in mice.

By targeting the spleen, the researchers are hopeful that the overall effect on the body will be lessened, but it is still unknown if long term ultrasound stimulation will have any harmful effects. A clinical study is currently underway to assess the safety and effectiveness of the method for treatment of rheumatoid arthritis in humans.