SPINAL CORD STIMULATION TREATMENT IN A PORCINE MODEL OF CHRONIC PAIN

Spinal cord stimulation (SCS) is a promising therapy for chronic pain, yet its paradigm-specific efficacy and underlying mechanisms remain poorly understood. This study aims to address that gap by examining these treatments in a porcine model of chronic pain. Peripheral nerve trauma (PNT) model was induced in six female Danish landrace pigs by ligation of the ulnar nerve with CFA-presoaked sutures on the right forelimb. Three weeks later, SCS leads were implanted epidurally at C6-8. Four paradigms, including 40-Hz at 80% motor threshold, 90-Hz at 40%, 1000-Hz at 40-60%, and SHAM, were applied in a randomized-crossover design, each lasting 3 days. Mechanical hypersensitivity test, measured weekly using pressure algometry on the right forelimb’s lateral side, showed reduced thresholds in PNT pigs, 54.98% on average over time compared to baseline (pre-injury) value. SCS effects appeared to be paradigm-specific, with the 90-Hz and 1000-Hz pigs exhibiting 87.97% and 70.31% changes, respectively, compared with pre-injury thresholds. Meanwhile, SHAM SCS pigs showed a 48.54% change, and the 40-Hz pigs showed a 57.22% change. Reduced motor control was observed with 40-Hz SCS. Regarding other tests, brush measurements did not show nerve intervention effects, whereas thermal hypersensitivity assessed with the laser test warrants further investigation. This is the first study evaluating SCS therapy in a porcine model of chronic pain, providing a platform to investigate its complex mechanisms. Ongoing experiments aim to unravel the electrophysiological effects of SCS. Using a highly translational species, our approach may help close the gap between rodent and human studies.