Terje Kirketeig: Spinal Cord Stimulation for Chronic Pain: Real-World Outcomes and Sham-Controlled Evidence

Abstract

Chronic neuropathic pain is associated with substantial suffering, reduced quality of life, impaired work ability, and high societal costs. Spinal cord stimulation (SCS) is an established treatment for selected patients with refractory neuropathic pain, but important uncertainties remain regarding real-world outcomes, long-term treatment burden, societal impact, and efficacy beyond placebo for newer stimulation paradigms. The overall aim of this thesis was to evaluate SCS using complementary observational and experimental approaches. This thesis comprises four studies. Paper I examined nationwide Swedish register data on work disability and indirect costs before and after SCS in working-age patients, compared with matched controls. Paper II evaluated patient-reported analgesic outcomes and explantation due to insufficient pain relief in a registry-based cohort linked to national registers. Paper III analyzed a prospective clinical registry to characterize adverse events and their temporal patterns during long-term neurostimulation therapy. Paper IV was a two-center, randomized, blinded, sham-controlled triple-crossover trial evaluating passive-recharge burst SCS in patients with painful radiculopathy. In Paper I, SCS was associated with 21 fewer net disability days and lower indirect costs of approximately €4,100 per patient, although the effect was modest relative to the high baseline level of work disability. In Paper II, outcomes in routine care were heterogeneous: at one year, 48% of patients reported at least 30% pain reduction, while the cumulative risk of explantation due to insufficient pain relief was 10% at two years and 21% at ten years. In Paper III, 41% of patients experienced at least one adverse event during a mean follow-up of 3.6 years, with lead migration, implant-site pain, and lead fracture accounting for most events. In Paper IV, passive-recharge burst SCS did not demonstrate superiority over sham. In conclusion, SCS appears to provide meaningful benefit for some patients, but outcomes are heterogeneous and accompanied by substantial long-term treatment burden. The sham-controlled findings further indicate that one established SCS paradigm may not provide benefit beyond placebo under controlled conditions. These findings support cautious patient selection, realistic risk–benefit communication, long-term follow-up, and continued use of independent registries and sham-controlled trials in the evaluation of neuromodulation therapies.