Evaluating Improvement in Pain and Sensory Function When Using High-Frequency (10-kHz) Spinal Cord Stimulation in Individuals With Painful Diabetic Neuropathy: A Multicenter Randomized Controlled Trial (PDN-Sensory)

OBJECTIVE: The PDN-Sensory randomized controlled trial (RCT) evaluated the effects of high-frequency 10-kHz spinal cord stimulation (10-kHz SCS) on pain and sensory function in individuals with painful diabetic neuropathy (PDN). RESEARCH DESIGN AND METHODS: Participants were randomized 1:1 to conventional medical management (CMM) alone or 10-kHz SCS plus CMM. The primary and key secondary end points were the proportions of participants with pain response (≥50% lower limb pain relief) and sensory improvement (≥3-point reduction in modified Toronto Clinical Neuropathy Score [mTCNS]). Hierarchical secondary outcomes included intraepidermal nerve fiber density (IENFD), sleep, and health and neuropathy-related quality of life (QoL). IENFD and mTCNS assessments were allocation blinded. RESULTS: A total of 91 participants were randomly assigned to CMM alone (n = 50) or 10-kHz SCS plus CMM (n = 41). In a modified intention-to-treat worst-case analysis, 27 of 34 participants in the 10-kHz SCS group who underwent a temporary trial achieved the primary outcome, versus 2 of 50 CMM-alone participants (P < 0.001). Among those with 6-month data, mTCNS sensory improvement was observed in 16 of 29 (55.2%) 10-kHz SCS participants versus 12 of 48 (25.0%) CMM-alone participants (P = 0.01). The mean change in lower-calf IENFD was 0.58 fibers/mm with 10-kHz SCS versus -0.07 with CMM alone (P = 0.03). Eight of 10 hierarchical secondary end points were met (including sleep and QoL). CONCLUSIONS: The PDN-Sensory RCT replicated previous pain-reduction findings and showed prespecified, objective improvements in sensory function and IENFD. These 6-month findings support clinically meaningful benefit and are consistent with a potential disease-modifying effect that requires longer-term confirmation.