A transcutaneous electrical nerve stimulation device for the relief of neuropathic pain in NMOSD: A randomized, double-blind, sham-controlled trial

Background Individuals with neuromyelitis optica spectrum disorder (NMOSD) often suffer from severe, disabling, and treatment-refractory neuropathic pain. Transcutaneous electrical nerve stimulation (TENS) therapy is a non-invasive, pain-modifying device.Objective To determine whether TENS therapy is safe, tolerable, and effective for neuropathic pain in patients with NMOSD.Methods We conducted a four-week, randomized, double-blind, sham-controlled, remote trial of TENS in patients with NMOSD who have neuropathic pain, followed by a 12-week open-label extension period. The difference in the Numeric Rating Scale current pain scores between 0 weeks and 4 weeks was the primary outcome measure.Results Forty-six patients (23 per arm) were enrolled in this trial, of which 40 were included in the primary analysis (four in the intervention arm and two in the sham arm withdrew prior to assessment of the primary outcome). Both the sham and intervention arms demonstrated significant decreases in average pain, worst pain, and current pain rating between baseline and 4 weeks, but there was no significant difference between the two arms.Conclusions In conclusion, there was no demonstrated benefit of TENS over sham TENS treatment, however, both arms demonstrated significant decreases in reported pain between baseline and 4 weeks. This trial is registered with ClinicalTrials.gov, NCT04614454.