Efficacy of recurrent transcutaneous magnetic stimulation in the treatment of diabetic peripheral neuropathy: Multicenter randomized trial.

Aims: Transcutaneous magnetic stimulation (TCMS) is successful in decreasing pain in several neurologic conditions. This multicenter parallel double-blind phase II clinical trial is a follow-up to a pilot study that demonstrated pain relief in patients with diabetic peripheral neuropathy (DPN) treated with TCMS.

Methods: Thirty-four participants with confirmed DPN and baseline pain score ≥ 5 were randomized to treatment at two sites. Participants were treated with either TCMS (n = 18) or sham (n = 16) applied to each foot once a week for four weeks. Pain scores using the Numeric Pain Rating Scale after 10 steps on a hard floor surface and answers to Patient-Reported Outcomes Measurement Information System pain questions were recorded by participants daily for 28 days.

Results: Thirty-one participants completed the study and were analyzed. Average pain scores decreased from baseline in both the groups. The difference in pain scores between TCMS and sham treatments was -0.55 for morning, -0.13 for evening, and -0.34 overall, below the pre-determined clinically relevant difference of -2. Moderate adverse events that resolved spontaneously were experienced in both treatment arms.

Conclusion: In this two-arm trial, TCMS failed to demonstrate a significant benefit over sham in patient reported pain suggesting a substantial placebo effect in our previous pilot study.

Trial Registration: TCMS for the Treatment of Foot Pain Caused By Diabetic Neuropathy, https://clinicaltrials.gov/ct2/show/NCT03596203, ID-NCT03596203.