Tonic Spinal Cord Stimulation Reduces Diabetic Neuropathy Pain

By Lisa Rappaport

July 22, 2020

(Reuters Health) - Tonic spinal cord stimulation (t-SCS) can help relieve pain from diabetic neuropathy, and some newer neuromodulation therapies also have potential, a systematic review and meta-analysis suggests.

Researchers examined data from 15 previously published studies that looked at pain outcomes for people with diabetic neuropathy who received different types of invasive neuromodulation. For the meta-analysis, researchers converted pain scores in the smaller studies to a standard 100-point scale to examine the effectiveness of techniques including t-SCS, dorsal root ganglion stimulation (DRGS), high frequency spinal cord stimulation (hf-SCS), and burst spinal cord stimulation (b-SCS).

The majority of evidence to date supports use of t-SCS, a more established treatment, and other approaches show some promise but require more evaluation, the study team writes in Neuromodulation.

Two randomized controlled trials found t-SCS improved pain more than what researchers called "best medical therapy" at six months (38/100, 95% CI 29-47). At 12 months, per-protocol case series found pain improved by 56 with t-SCS (95% CI: 39-73) and by 55 with DRGS (95% CI: 22-87).

"The findings do suggest both dorsal root ganglion stimulation and tonic conventional spinal cord stimulation have a significant chance of helping those with diabetic induced neuropathy," said Dr. Timothy Deer, president and chief executive of the Spine and Nerve Center of the Virginias in Charleston, West Virginia, who wasn't involved in the study.

Patients should first be treated with more conservative intervention for pain due to diabetic neuropathy including controlling blood sugar, non-opioid medications, and physical therapy, Dr. Deer said by email. Temporary neuromodulation should also be tried and show a significant amount of pain relief before moving forward with a permanent device, said Dr. Deer, who has financial ties to companies including Medtronic, Abbott, Boston Scientific, Nevro, Nalu, and Saluda.

Additional long-term studies are needed to help determine which patients are the best candidates for invasive neuromodulation for pain due to diabetic neuropathy, Dr. Deer said.

With t-SCS, the analysis also found that the risk of failing to respond to treatment was 16% and the infection risk was 4%.

In addition, the risk of lead problems that required revision surgery was 13%, with a rate of 4% per year of follow-up. There was no risk of implanted pulse generator replacement at six months, but this risk rose to 12% at two years, 17% at three years, and 45% at five years.

After permanent implantation of t-SCS, the risk of removal at five years was 20%.

There was insufficient evidence to make determinations about the safety or effectiveness of b-SCS, hf-SCS, or DRGS, the study authors note.

"Most of the evidence is with SCS with very limited case series and reports for DRGS and only one case report of deep brain stimulation in a patient with perineal pain which is not diabetic painful neuropathy," said Dr. Rayaz Malik, a professor of medicine at Weill Cornell Medicine-Qatar who wasn't involved in the study and reported no financial ties to companies that produce treatments for painful diabetic neuropathy.

"SCS or DRGS are options for patients who are refractory to conventional medical therapy used as single agents or in combination as well as topical therapies," Dr. Malik said by email.

Multiple authors involved in the study have received funding such as grants and personal fees from companies including Abbott, NovoNordisk, and Medtronic. Lead and corresponding author Ashley Raghu of the University of Oxford in the UK didn't respond to requests for comment.

SOURCE: Neuromodulation, online June 26, 2020.