A study has found that restorative neurostimulation continues to be effective in treating low-back pain caused by multifidus dysfunction after three years. This type of dysfunction occurs when the multifidis muscles, which are important to spine stability, are inhibited by back pain from intervertebral discs and facet joints. An implanted restorative neurostimulation device has electrodes that stimulate the nerves that control these muscles. Patients can self-administer the treatment for up to 60 minutes per day.
The Food and Drug Administration approved the device after one year of successful study results, but researchers at Brigham and Women's Hospital, Harvard Medical School, in Boston, MA, have continued to study patients using the device to evaluate long-term effectiveness.
Dr. Christopher Gilligan, the principal investigator on the ReActiv8-B study, said the results indicate that this procedure offers "an effective, durable, and safe treatment for patients with disabling chronic low-back pain associated with multifidus dysfunction." Dr. Gilligan is the lead author of the abstract, "3-Year Durability of Symptom Relief with Restorative Neurostimulation for Chronic Mechanical Low Back Pain," which was chosen as one of the 21st Annual Pain Medicine Meeting's Best of Meeting abstracts. Dr. Gilligan will present the findings at a session on Friday, November 18, at 8 am, at the Hilton Bonnet Creek in Orlando, FL.
At the start of the study, participants on average were relatively young (47 years) and had severe back pain scores (7.3 out of 10) for 14 years. Three-year data available for 133 participants showed that three-quarters of them reported a greater than 50% reduction in pain; two-thirds reported resolution of pain (defined as less than 2.5 out of 10 pain score); and two-thirds had an Oswestry Disability Index improvement of greater than 20 out of 100 points. The majority (83%) had a clinically substantial improvement in pain and/or disability, and 86% said that they were "definitely satisfied" with the treatment.
Patients' disabling chronic low-back pain had been previously treated with medical management, which included at least pain medications and physical therapy. They had no indications for spine surgery and tested positive on the prone instability test, a physical test for multifidus dysfunction. All participants were followed up at 1, 2 and 3 years.
Of participants using opioids before study start, 49% had voluntarily discontinued them. Gilligan reported that the overall safety profile of the therapy is favorable compared to other published neurostimulation studies for chronic pain and no lead migrations were observed, which is a potential complication of implanted stimulation devices.