188 Randomized Controlled Clinical Trial Evaluating the Safety and Effectiveness of 10 kHz High-Frequency and Traditional Low-Frequency Stimulation for the Treatment of Chronic Back and Leg Pain: 18-Month Results.

INTRODUCTION: A randomized controlled trial with appropriate statistical power and long-term outcomes is the hallmark of level 1 clinical evidence. The SENZA-RCT multicenter pivotal study was powered to directly compare highfrequency spinal cord stimulation (SCS) at 10 kHz (HF10 therapy) and traditional lowfrequency (∼50 Hz) SCS. The comparative efficacy of these modalities for the treatment of chronic back and leg pain for 18 months is presented.

METHODS: Baseline assessments were performed before the randomization of 198 patients. One hundred seventy-one patients responded during a trial phase of the assigned SCS system and were implanted. Eighteen month results were available for 165 of these patients. Responders were defined as having at least 50% pain reduction, while pain remitters were defined as having a VAS pain score of 2.5 or less out of 10.

RESULTS: At 18 months, back pain decreased to a greater degree for patients receiving HF10 therapy (64.9% ± 30.8%) than with traditional SCS (42.5% ± 35.9%), P < .001. Similarly, leg pain decreased to a greater degree for HF10 therapy patients (65.4% ± 35.2%) than with traditional SCS (45.0% ± 40.3%), P < .001. More patients were pain responders to HF10 therapy than traditional SCS (back pain: 75.9% for HF10 therapy, 47.7% for traditional SCS, P < .001; leg pain: 77.0% for HF10 therapy, 53.8% for traditional SCS, P < .001). More patients were also pain remitters with HF10 therapy than traditional SCS (back pain: 62.1% for HF10 therapy, 30.8% for traditional SCS, P < .001; leg pain: 64.4% for HF10 therapy, 38.5% for traditional SCS, P < .001). Patients classified as remitters in both groups combined had a back pain score of 1.2 ± 0.8 and a leg pain score of 1.0 ± 0.8. Safety profiles were similar.

CONCLUSION: The SENZA-RCT study provides strong level 1 evidence in support of long-term use HF10 therapy compared with traditional low-frequency SCS for the treatment of chronic back and leg pain.