Objective:Long-term outcomes of percutaneous image-guided lumbar decompression for treatment of lumbar spinal stenosis with neurogenic claudication secondary to hypertrophic ligamentum flavum were assessed using extended follow-up of the treatment group in the MOTION prospective, multicenter randomized controlled trial. Originally performed with a control group consisting solely of conventional medical management (CMM-Alone), follow-up of the treatment group was extended to five years and analyzed as a modified intent-to-treat group. Methods:Spinal decompression was performed using the mild® Procedure (Stryker Corporation, Portage, MI, USA), with the treatment group also receiving CMM with no restrictions post-procedure (mild + CMM). Subjective outcomes were measured using validated patient-reported questionnaires including the Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ), and Numeric Pain Rating Scale (NPRS). Objective measurements included a validated Walking Tolerance Test (WTT), the rate of subsequent lumbar spine interventions (SLSI), and the occurrence of adverse events. An ad hoc analysis comparing 5-year outcomes for patients who were at least 65 years of age at the time of treatment to those of younger patients was also performed. In addition, long-term (4-year) outcomes were assessed for CMM-Alone patients who subsequently received the mild Procedure for relief of ongoing symptoms (crossover group). Results:As with the 1-, 2- and 3-year follow-up visits, all outcomes at the 5-year visit for the mild + CMM group remained significantly improved over baseline (N = 34, p < 0.0001), with ODI, NPRS back and leg, and ZCQ Symptom Severity and Physical Function improving by 20.6, 2.5, 4.6, 0.9, and 0.7, respectively. Walking times increased 326% from baseline, with three additional SLSI performed since the 3-year follow-up. No device- or procedure-related adverse events were reported over the entire 5-year follow-up period. At 5 years post-treatment, no significant differences in outcomes between older and younger patients were seen for any outcome. No significant differences were found in the crossover group when compared to the mild + CMM group using 4-year follow-up results. Conclusions:The use of the percutaneous mild Procedure, together with CMM, is shown to provide a safe, effective and durable treatment for symptomatic LSS. The procedure appears effective regardless of patient age at the time of treatment. Further, the ability of the mild Procedure to improve patient outcomes does not appear to be affected in those patients whose treatment is delayed by continued use of CMM.
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.
Peripheral nerve stimulation (PNS) has evolved substantially over recent decades in terms of hardware and evidence supporting efficacy. Treatment targets continue to expand and address both pain and functional applications. The American Society of Pain and Neuroscience (ASPN) seeks to substantially update and expand upon a review of the evidence supporting PNS as well as provide guidelines for clinical practice. A diverse multidisciplinary panel of experts was selected to provide opinions and guidance based on evidence-graded assessment and clinical knowledge. This document aims to serve as a resource for clinicians and payors in the interest of expanding awareness of the breadth of research in the field of PNS and expanding access to therapy.
BACKGROUND:The efficacy of EVOKE therapy, a closed-loop spinal cord stimulation (SCS) system, has been demonstrated in a double-blinded randomized controlled trial (RCT). RCT evidence, however, may not be generalizable to clinical practice, while limitations of real-world evidence may affect its validity. The aim of this study was to evaluate the effectiveness of EVOKE therapy in routine clinical practice employing a rigorous data collection approach. METHODS:The ECAP study was a prospective, multicenter, single-arm, pragmatic study that enrolled SCS candidates with chronic, intractable trunk and/or limb pain in 22 US investigational sites. PROMIS-29 questionnaire and objective neurophysiological metrics were collected, and minimal clinically important differences (MCIDs) were used to characterize baseline dysfunction and response to EVOKE therapy both at trial end and maximal analgesic effect post-implant visit. Pre-specified subgroup analyses were conducted based on diagnosis. RESULTS:EVOKE therapy observed included a dose ratio of 1.3 and neural dose accuracy of 2.8 μV. Improvements of >1 MCID were observed for all domains and improvements of ≥2 MCIDs were observed for six of the seven domains. Improvements observed at trial end were maintained or improved at post-implant visit, with statistically significant improvement in holistic MCID (MD 0.2, 95% CI 0.1 to 0.4, p=0.004), and a significantly greater proportion of patients considered holistic MCID responders (p=0.047). Subgroup analysis by diagnosis showed similar outcomes. CONCLUSIONS:EVOKE therapy was associated with clinically meaningful improvements in a real-world chronic pain population across different subgroups and disease pathologies, with effects observed at trial end reproduced at post-implant visit.
