Randomized Trial of Scrambler Therapy for Chemotherapy-Induced Peripheral Neuropathy: Crossover Analysis

Context: Preliminary trials report that Scrambler Therapy, a form of electroanalgesia, may improve discomfort from chemotherapy-induced peripheral neuropathy (CIPN). Objective: The objective of this phase II, randomized controlled trial was to evaluate the efficacy of Scrambler therapy vs. transcutaneous electrical nerve stimulation (TENS) in treating CIPN. Methods: Fifty patients were accrued for the first half of this two-part, crossover trial consisting of a 2-week treatment period with either Scrambler or TENS, followed by an 8-week observation period, and then crossover treatment. Twenty-two patients proceeded to the crossover phase. The primary means of assessment was patient-reported outcomes, including symptom severity scales and Global Impression of Change questionnaires. Symptoms were assessed daily during the treatment period and weekly during an 8-week observation period. Results: A 50% or greater reduction in primary symptom (pain or tingling) score on the last day of treatment was achieved by 6 of 10 Scrambler-treated patients (60%) and 3 of 12 TENS-treated patients (25%) after crossover (P = 0.11). By day 4 of treatment, the two arms diverged with respect to mean change in primary symptom score; this effect was largely carried through to the end of the two-week treatment period. Similarly, Scrambler therapy appeared better than TENS when assessed by Global Impression of Change for neuropathy, pain, and overall quality of life. Conclusions: Similar findings from the initial randomization and crossover phases of this study support further evaluation of the efficacy of Scrambler therapy in alleviating CIPN symptoms. Evaluation in a larger, randomized controlled trial with standardized treatment is warranted.