Introduction

Spinal Cord Stimulation (SCS) is regularly utilized at amplitudes below perception threshold enabling patients to achieve paresthesia-free pain relief. Despite success of this approach, to date, patients utilizing this method do not report onset of pain relief for up to 24-48 hours. The drawback to this latent interval between stimulation and clinical effect are the constraints imposed on identification of the optimal parameters that allow for maximum pain relief within each patient. We conducted an observational case-series using a new, paresthesia-free SCS technique that was reported to elicit pain relief within seconds to minutes after initial stimulation.

Methods/Materials

This is a single-center, observational case-series of de novo patients permanently-implanted for up to 6-months post-implant. A neurostimulator (Spectra WaveWriter) was used that provides high-resolution neural targeting capabilities and a proprietary algorithm designed to facilitate therapeutic paresthesia-free stimulation in combination with a tightly-spaced contact lead(s). Data was collected per standard of care which included reporting of pain scores (NRS).

Results

So far, 6 patients with chronic pain (diagnoses: FBSS, CRPS) were assessed in this evaluation. At baseline, mean NRS pain score was found to be 8.17 (±0.21, S.E). The mean NRS following initial programming of patient-specific stimulation parameters [paresthesia-free stimulation ON] was 0.58 (±0.24, S.E). All patients were observed to achieve paresthesia-free pain relief within seconds of turning on stimulation. Additionally, mean NRS at 3-month follow-up was 1.17 (±0.54, S.E).

Discussion

Intriguingly, the results obtained in this initial real-world observational study are consistent with those reported by Metzger. This would suggest that achieving pain relief using sub-perception SCS is possible and that a putative mechanism of action is potentially mediating rapid onset of analgesia. Furthermore, we observed that precise targeting of neural stimulation seemed to be required to obtain these clinical outcomes. The implications of this study suggest that this approach may be a more beneficial way of employing paresthesia-free SCS as it enables much faster identification of a patient’s unique “sweet spot(s)” and provides pain relief almost instantaneously.

Conclusions

In conclusion, we observed patients who used this new method of paresthesia-free SCS achieve very substantial pain relief within seconds that was sustained out to 3-months post-implant. In our experience, this is an unprecedented observation using paresthesia-free SCS. Therefore, these results strongly argue in favor for additional studies and a randomized controlled trial.

References

Tiede J, Brown L, Gekht G, Vallejo R, Yearwood T, Morgan D. Novel spinal cord stimulation parameters in patients with predominant back pain. Neuromodulation. 2013 Jul-Aug;16(4):370-5.

Al-Kaisy A, Van Buyten JP, Smet I, Palmisani S, Pang D, Smith T. Sustained effectiveness of 10 kHz high-frequency spinal cord stimulation for patients with chronic, low back pain: 24-month results of a prospective multicenter study. Pain Med. 2014 Mar;15(3):347-54.

Metzger, Clark. “A Novel Sub-Perception SCS Therapy Enabling Clinically Significant Pain Relief and Fast Onset” [Abstract]. Biennial Meeting of the International Neuromodulation Society (INS), 2019.