10khz SCS Provides Effective Treatment for Non-surgical Back Pain Across Pain Types, Including Nociceptive

Introduction: Spinal cord stimulation (SCS) has been traditionally understood to only treat neuropathic pain,1 but it is commonly understood that many patients with chronic pain have mixed pain types, and a nociplastic category has also been defined related to altered nociception due to central sensitization.2 10 kHz SCS was demonstrated superior to traditional SCS (tSCS) in 2015,3 with the capability to do anatomical placement of leads, and lack of paresthesia side effect suggesting a different mechanism of action from tSCS.4,5 It is uncertain if this different mechanism of action would provide higher likelihood of treating non-neuropathic pain. This analysis was designed to understand if pain type influences therapeutic outcome with 10 kHz SCS.

Methods: The painDETECT questionnaire has been accepted as a valid method to quantify neuropathic pain,6 and was administered to patients enrolled in an RCT evaluating 10kHz SCS for the treatment of nonsurgical back pain (NSRBP-RCT).7 The baseline painDETECT score and the 24-month responder status from 125 implanted patients who participated in the NSRBP RCT were included in this analysis. A painDETECT score < 13 indicates nociceptive pain, a score between 13 and 19 is defined as “unclear”, a score ≥19 indicates neuropathic pain component is likely. A chi-square test of independence was performed to examine the relation between pain type (PainDETECT grouping) versus 24-month responders achieving ≥50% pain relief (yes/no) with 10 kHz SCS therapy.

Results: Table 1 indicates the distribution of pain types (nociceptive, unclear, neuropathic) across the 125 patients treated in the NSRBP-RCT. The distribution shows that patient selection led to an uneven distribution across pain types (χ2 (2, N = 125) = 8.13, p = 0.017). The responder rates for each of the pain types are shown in Table 1, with a trend towards higher responder rate for patients with neuropathic pain type, but pain type did not significantly influence outcome based on chi-square analysis. The distribution of PainDETECT scores for both responders and non-responders is shown in Figure 1.

Conclusion: This analysis demonstrates the treatment efficacy of 10 kHz SCS across a wide range of pain types, from neuropathic to nociceptive/nociplastic. It may be that the putative mechanism of 10 kHz SCS (predominant drive of inhibitory dorsal horn neurons 4 ) can be effective in reducing spinal central sensitization, a hallmark of both neuropathic and nociplastic pain.