Novel Intermittent Dosing Burst Paradigm in Spinal Cord Stimulation

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.

Keywords: chronic pain; cycling; intermittent dosing burst; spinal cord stimulation.

© 2020 The Authors. Neuromodulation: Technology at the Neural Interface published by Wiley Periodicals LLC on behalf of International Neuromodulation Society.

Figures

Figure 1

Schematic representation of post‐trial IDB titration process. [Color figure can be viewed at wileyonlinelibrary.com]

Figure 2

(a): IDB program usage at the six‐month follow‐up visit. (b) Average ODI scores at the six‐month follow‐up of subjects who used the three shorter OFF periods and subjects who used the longer OFF periods (150, 120, and 90 sec OFF). Error bars represents 95% confidence intervals. Statistical differences were observed between the two OFF groups using a Mann–Whitney test. [Color figure can be viewed at wileyonlinelibrary.com]

Figure 3

Effect of titrated IDB SCS on pain. Overall (a), back (b), and leg (c) average pain at baseline and at follow‐up visits (p < 0.001). Error bars represents 95% confidence intervals. Statistical differences were observed between baseline and all other follow‐up visits using Friedman's test. [Color figure can be viewed at wileyonlinelibrary.com]

Figure 4

Effect of titrated IDB SCS on subjects' functionality. (a) Average EQ‐5D scores at baseline, trial and at follow‐up visits (p < 0.001); dashed line represents U.S. population norm for age group 55–64 years (0.776 (22)), error bars represents 95% confidence intervals. Statistical differences were observed between baseline and all other follow‐up visits using Friedman's test. (b) Percentage of subjects in each of the Oswestry Disability Index categories at baseline, trial, and at follow‐up visits. [Color figure can be viewed at wileyonlinelibrary.com]

Figure 5

Effect of titrated IDB SCS on subjects' perception of pain and impression of change. (a) Average Pain Catastrophizing Scale scores (p < 0.001); dashed line represents nonpain population norm (13.9 (20)), error bars represents 95% confidence intervals. Statistical differences were observed between baseline and all other follow‐up visits using Friedman's test. (b) Average Pain Catastrophizing Scale subcomponents, error bars represent 95% confidence intervals. (c) Patient General Impression of Change at the six‐month follow‐up visit; blue box contains the categories that reported “somewhat better” or more marked impression of change. [Color figure can be viewed at wileyonlinelibrary.com]