Evaluating pain and neurological function with high frequency 10 kHz spinal cord stimulation in the treatment of painful diabetic neuropathy: design of a multicentre, randomised controlled trial (PDN-Sensory)

Introduction Current pharmacological treatment options for painful diabetic neuropathy (PDN) often fail to provide adequate pain relief. However, in the recent SENZA-PDN study, high-frequency 10 kHz spinal cord stimulation (SCS) demonstrated significant long-term improvements in lower limb pain and health-related quality of life (HRQoL) in a PDN population. Furthermore, more than half of 10 kHz SCS recipients showed improved sensory function based on non-blinded clinical assessments in post hoc analysis. We report the design of the PDN-Sensory study, which aims to evaluate changes in pain and neurological function with 10 kHz SCS in the treatment of PDN. The study will include objective measures of neurological function, including the modified Toronto Clinical Neuropathy Score (mTCNS) and intraepidermal nerve fibre density (IENFD).

Methods and analysis This multicentre, prospective, randomised controlled trial will compare conventional medical management (CMM) with 10 kHz SCS+CMM in individuals with diabetes and chronic, intractable lower limb pain due to PDN. Participants will be randomised 1:1 to CMM alone or 10 kHz SCS+CMM, with optional crossover at 6 months. The primary outcome is the proportion of participants at 6 months achieving ≥50% pain relief from baseline. The key secondary endpoint is the proportion of participants at 6 months with a reduction in mTCNS of ≥3 points from baseline (excluding changes in foot pain). Additional endpoints at 6 and 12 months include changes from baseline in mTCNS, IENFD, 7-day averaged pain score, pain-related interference, HRQoL, sleep, psychological outcomes, functional status and metabolic parameters.