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

Preliminary trials report that Scrambler Therapy, a form of electroanalgesia, may improve discomfort from chemotherapy-induced peripheral neuropathy (CIPN). 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. 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. 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. 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.