By Ted Swing, Ph.D.
Advancements in pain medicine depend primarily on clinical research trials carried out by private companies called “sponsors” under the supervision of the Food and Drug Administration (FDA). We take part in many of these studies, enrolling appropriate patients and delivering the new treatments to them. From 2012 to 2014, we took part in a study with Bioness testing an implanted device called the StimRouter.
The clinical trial tested this device for patients experiencing pain in a single peripheral nerve. “Peripheral nerve” simply means that the nerve is found outside of the head, neck or back. The pain typically affects part of a single limb along the path of the affected peripheral nerve. This type of pain may occur as a result of a physical injury or a surgical procedure. In some cases, even after the body has healed from the immediate injury, the affected nerve continues to send pain signals and this pain can last for years.
We enrolled 22 patients — the most of any site taking part in the study — who had moderate to severe pain to take part in this study. Another 104 patients were enrolled from more than ten other sites around the U.S. Each of these patients had a StimRouter implanted and were followed up for 12 months. The lead, a six-inch-long wire with three electrodes at one end, is implanted along the affected nerve. A rechargeable external pulse generator measuring roughly 1”x 2” x 1/2” is placed on the skin over the implanted lead with an adhesive patch. It delivers mild electrical stimulation through the skin, which the StimRouter lead directs to the target nerve. This electrical stimulation is perceived as a mild tingling sensation, which replaces the sensation of pain that normally comes from the limb.
For the first three months, half of the patients had the StimRouter set to a therapeutic setting and the other half had it set to a non-therapeutic setting to serve as an untreated comparison group. Patients and clinical staff were blinded as to the type of stimulation patients were receiving during this time. After three months, all devices were set to deliver therapeutic stimulation and continued to receive this for the remainder of the study. Patients were able to continue to use the devices after the end of the study.
During the initial three-month period, patients receiving therapeutic stimulation reported significantly greater reductions in pain than control patients. Many treated patients received 50% or greater pain relief. The device also proved safe and easy to use. Earlier this year, based on these results, Bioness received FDA approval for the StimRouter. This device is now available to the general public.
If you are interested in learning more about this device and whether this or another similar treatment may be right for you, you can discuss this study with your pain management providers. For additional information about this study you can contact me directly at TedS@arizonapain.com.
Ted Swing has more than 11 years of research experience in psychology and pain medicine and four years of teaching experience, has published in top psychology and medical journals, and has presented his research at major conferences. He received his Ph.D. in Social Psychology from Iowa State University and has been the Research Director at Arizona Pain since May 2012.