Abstract
INTRODUCTION: Intermittent dosing (ID), in which periods of stimulation-on are alternated with periods of stimulation-off, is generally employed using 30 sec ON and 90 sec OFF intervals with burst spinal cord stimulation (SCS). The goal of this study was to evaluate the feasibility of using extended stimulation-off periods in patients with chronic intractable pain. MATERIALS AND METHODS: This prospective, multicenter, feasibility trial evaluated the clinical efficacy of the following ID stimulation-off times: 90, 120, 150, and 360 sec with burst waveform parameters. After a successful trial (≥50% pain relief) using ID stimulation, subjects were titrated with OFF times beginning with 360 sec. Pain, quality of life, disability, and pain catastrophizing were evaluated at one, three, and six months after permanent implant. RESULTS: Fifty subjects completed an SCS trial using ID stimulation settings of 30 sec ON and 90 sec OFF, with 38 (76%) receiving ≥50% pain relief. Pain scores were significantly reduced from baseline at all time points (p < 0.001). Improvements in quality of life, disability, and pain catastrophizing were aligned with pain relief outcomes; 45.8% of the subjects that completed the six-month follow-up visit used an OFF period of 360 seconds. CONCLUSIONS: ID burst SCS effectively relieved pain for six months. The largest group of subjects used IDB settings of 30 sec ON and 360 sec OFF. These findings present intriguing implications for the optimal "dose" of electricity in SCS and may offer many advantages such as optimizing the therapeutic window, extending battery life, reducing recharge burden and, potentially, mitigating therapy habituation or tolerance.