Efficacy of Closed Loop Spinal Cord Stimulation for Chronic Back and Leg Pain: A Systematic Review

ABSTRACT Background Spinal cord stimulation (SCS) is an established therapy for chronic pain of the trunk and limbs. Conventional open‐loop systems are sometimes limited by habituation, positional variability, and inconsistent neural recruitment. Closed‐loop SCS is an approach that uses evoked compound action potentials (ECAPs) to adjust stimulation in real time to maintain consistent therapeutic effects. A systematic review is indicated to bring clarity to the efficacy and safety of these systems. Objective To evaluate the efficacy of closed‐loop SCS for chronic back and leg pain in persistent spinal pain syndromes. Methods A comprehensive search of MEDLINE, Embase, Scopus, ScienceDirect, Cochrane Library, Google Scholar, and clinicaltrials.gov was conducted through April 2025. Eligible studies included Randomized Controlled Trials (RCT), prospective or retrospective cohort studies, and real‐world observational studies evaluating closed‐loop SCS in adults with lumbar radiculopathy, chronic back and leg pain, or persistent spinal pain syndromes. Outcomes included pain intensity, percentage of pain relief, disability, health‐related quality of life, mood, sleep, and opioid use. Risk of bias was assessed using the Review Manager (Revman) tool within the Cochrane Collaboration resources. Results Four eligible studies met inclusion criteria for chronic back and leg pain, with responder rates (≥ 50% pain reduction) ranging from 68% to 92% and high‐responder rates (≥ 80% pain reduction) from 50% to 60% across follow‐up periods up to 36 months. Significant improvements were observed in disability (ODI), sleep quality (PSQI), mood (POMS), and quality of life (EQ‐5D‐5L). The EVOKE RCT trial demonstrated closed‐loop SCS superiority over open‐loop stimulation in both pain reduction and functional outcomes. Opioid use decreased substantially, with up to 83% of patients reducing or discontinuing opioids at 24 months. Reported adverse events were consistent with those seen in conventional SCS, and no unexpected safety concerns were identified. Conclusion Growing evidence suggests closed‐loop SCS provides predictive and durable pain relief with concurrent functional improvements in chronic back and leg pain, with additional benefits in opioid reduction for persistent spinal pain syndromes. Trial Registration PROSPERO registration number: CRD42024580458