Scrambler therapy improves pain in neuromyelitis optica: A randomized controlled trial

Abstract

Objective: To determine whether Scrambler therapy is an effective, acceptable, and feasible treatment of persistent central neuropathic pain in patients with neuromyelitis optica spectrum disorder (NMOSD) and to explore the effect of Scrambler therapy on co-occurring symptoms.

Methods: We conducted a randomized single-blind, sham-controlled trial in patients with NMOSD who have central neuropathic pain using Scrambler therapy for 10 consecutive weekdays. Pain severity, pain interference, anxiety, depression, and sleep disturbance were assessed at baseline, at the end of treatment, and at the 30- and 60-day follow-up.

Results: Twenty-two patients (11 per arm) were enrolled in and completed this trial. The median baseline numeric rating scale (NRS) pain score decreased from 5.0 to 1.5 after 10 days of treatment with Scrambler therapy, whereas the median NRS score did not significantly decrease in the sham arm. Depression was also reduced in the treatment arm, and anxiety was decreased in a subset of patients who responded to treatment. These symptoms were not affected in the sham arm. The safety profiles were similar between groups.

Conclusions: Scrambler therapy is an effective, feasible, and safe intervention for central neuropathic pain in patients with NMOSD. Decreasing pain with Scrambler therapy may additionally improve depression and anxiety.

Clinicaltrialsgov identifier: NCT03452176.

Classification of evidence: This study provides Class II evidence that Scrambler therapy significantly reduces pain in patients with NMOSD and persistent central neuropathic pain.

© 2020 American Academy of Neurology.

Figures

Figure 1. Example of electrode placement for Scrambler therapy recipient

Electrode placement is demonstrated on a participant with neuromyelitis optica spectrum disorder with a cape pattern of pain from C3 to C8 dermatomal involvement. The goal is to surround the area of pain with pairs of electrodes. Each pair is indicated by a double blue arrow. An additional pair (not shown) went from the C2 to T1 region, to the right of the spinal column. Scrambler therapy electric signal travels between each pair of electrodes. The signal is alternating current, maximum 5.5 mA, maximum current density 0.0002009 W/cm2, and 16 different waveforms.

Figure 2. Consolidates Standard of Reporting Trials (CONSORT) flow diagram

Figure 3. Box and whisker plots depicting median change in NRS pain scores across time points

(A) Scrambler-treated and (B) sham arms. NRS = numeric rating scale.