Introduction: Spinal cord stimulation (SCS) is an established, effective method of treating chronic pain. High frequency stimulation (HFS) is an alternative SCS waveform that has been shown to alleviate pain but also necessitates more frequent recharging. The purpose of this pilot study is to evaluate efficacy of alternating conventional stimulation and HFS (termed "shuffle" stimulation) in improving SCS outcomes.
Methods: Shuffle stimulation was designed to deliver conventional stimulation in upright positions with relative HFS in lying positions, automated through accelerometer technology. In this 13-week cross-over study, patients were randomized to receiving conventional and shuffle stimulation in four-week blocks. Pain outcomes and sensory testing were compared from preoperative baseline and at the conclusion of each study period.
Results: Twelve patients completed this study. Two patients showed no change from baseline visual analogue scale (VAS) with either type of stimulation and were excluded from statistical analysis of pain outcomes. Mean numerical rating scale (NRS) scores assessing current pain were significantly lower in shuffle stimulation (4.0 ± 1.6) compared to conventional stimulation (5.8 ± 2.3) (p = 0.024). In the total cohort, 7 of 11 patients preferred shuffle over conventional stimulation.
Conclusions: This study generated preliminary evidence showing improved NRS current pain scores in shuffle stimulation compared to conventional stimulation. More patients preferred shuffle stimulation compared to conventional stimulation. Optimizing stimulation when patients are recumbent may increase patient satisfaction and pain control. The potential advantages of shuffle stimulation may warrant further investigation.
Keywords: Cross-over study; high frequency stimulation; pilot study; spinal cord stimulation; stimulation parameters.
© 2018 International Neuromodulation Society.