A systematic review of evidence comparing spinal cord stimulation to sham or conservative medical management in the treatment of persistent spinal pain syndrome - Type 2.

Objective: To assess the effectiveness of dorsal column spinal cord stimulation (SCS) in treating persistent spinal pain syndrome - Type 2 (PSPS-T2). Design: Systematic review. Methods: PICOS (Population, Intervention, Comparison, Outcomes, and Studies) criteria were developed to include randomized controlled trials (RCTs) examining dorsal column stimulation for PSPS-T2 compared to conventional medical management or sham. Eight reviewers independently assessed publications through April 2025 and utilized the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) framework to evaluate the overall quality of evidence. Outcomes included measures of pain, function, quality of life, and adverse events. Results: Of the 1988 publications initially screened, six publications were included, comprising a total of 448 participants, of which 257 were randomized to an SCS trial and 220 ultimately received SCS implants. Follow-up periods for the primary endpoints varied across the studies, ranging from 1 month to 2 years. For studies reporting success rates for achieving at least a 50% reduction in pain, responder rates spanned from 14% to 80% in the tonic SCS groups, compared with 3%-20% for CMM. The mean improvement in pain levels between 1 month and 6 months varied between 16% and 48% for tonic SCS, 16 and 17% for burst SCS, -15% and 16% for CMM, and 10 and 16% for sham. The mean improvement in function at six months ranged from 21 to 45% for the tonic SCS group, compared with 0-21% for CMM. Adverse events reported in these studies included lead migration (10-14%), IPG site pain (1-12%), infection (6.9-10%), and dural puncture (6%). Cochrane risk of bias assessments revealed low risks for one-third of the included studies, while some concerns were noted for over half of the studies. According to the GRADE system, based on the available RCTs, there is moderate-quality evidence overall that SCS is clinically effective in reducing pain and disability in patients with PSPS-T2 at 6 months. Discussion/conclusion: Substantial proportions of patients achieved ≥50% relief at 6 months following tonic SCS when compared with CMM, demonstrating clinical effectiveness. Significant improvements in function and quality of life were observed at study endpoints ranging from 3 to 24 months following tonic SCS. No studies included in this review utilized newer and potentially more effective SCS technologies such as closed loop, high frequency, or multiple waveform SCS. The only sham-controlled study included did not demonstrate efficacy of burst SCS. Adverse event rates, including infection and implant site pain, varied significantly between studies, with the newer and older studies representing the lower and upper ends of these ranges, respectively.