Pain Remission at One-Year Follow-Up With Spinal Cord Stimulation

Objectives: Spinal Cord Stimulation (SCS) is an effective treatment for chronic pain. How often pain remission follows SCS has not been evaluated. This is a retrospective analysis of patients who underwent an implantation of spinal cord stimulators for various chronic pain conditions. The objective of the study was to elucidate characteristics and features of patients with pain relief greater than 80% after one year of treatment.

Methods: A total of 86 patients with thoracic SCS and 12-month follow-up data were identified. Patients were divided into a remission group (>80% improvement in Numeric Pain Rating Scale [NRS] pain scale), average responders (20-80% improvement) and a non-responder group (less than 20% improvement). These patient groups were compared via the following outcome measures: NRS, Oswestry Disability Index (ODI), Pain Catastrophizing Scale (PCS), McGill Pain Questionnaire (MPQ), and Insomnia Severity Index (ISI). Correlations with age, body mass index (BMI), tobacco and alcohol usage, patient satisfaction with SCS, disability status, and opioid usage were assessed.

Results: Nineteen of 86 patients (22%) were remitters at one year follow-up, including 17 patients who had an NRS = 0 at that time. Upon analyzing the three patient groups (non-responders, average responders, and remitters), remitter patients showed the greatest change over the one-year post-operative period in ODI (F(2) = 8.101, p < 0.01) and PCS (F(2) = 7.607, p < 0.01). Moreover, remission was less likely when the patients were on disability prior to implant (χ² (2) = 6.469, p < 0.05) and on opioids pre-operatively (χ² (2) = 17.688, p < 0.01).

Conclusions: Our study demonstrates a remission rate of 22% with SCS at one-year follow with a total of 19.8% of our total patient cohort having an NRS of 0. Greater decreases in PCS and ODI correlate with remission. Further, pre-operative disability and opioid use correlate with lower likelihood of remission.