Multiphase Spinal Cord Stimulation in Participants With Chronic Back or Leg Pain: Results of the BENEFIT-02 Randomized Clinical Trial

Spinal Cord Stimulation Explantation and Chronic Pain: A Systematic Review and Technology Recommendations

Background

Chronic pain affects 20.5% of the US population, costing $296 billion annually in lost productivity. Spinal cord stimulation (SCS) has become a key treatment for refractory neuropathic and nociceptive pain, with increasing usage due to technological advancements. However, the durability of SCS therapy, including explantation rates, remains a concern. Understanding explantation causes is essential for improving patient selection and device effectiveness. This study aims to analyze SCS explantation rates and reasons, as well as evaluate the financial burden of these procedures on the healthcare system.

Methods

Three primary screening methods were used: manual search with keywords, MeSH term query, and reference list screening. The search covered PubMed, Cochrane, and Web of Science databases from inception to November 2024, yielding 719 articles. After applying eligibility criteria, 72 articles were identified, and 25 were selected for analysis. Data extraction was done by independent reviewers, with a second reviewer ensuring accuracy. Discrepancies were resolved by the corresponding editor.

Results

We reviewed data from 13,026 patients who underwent permanent SCS implantation between 1984 and 2024, across 25 studies. A total of 1882 patients (9.82%) underwent explantation. The most common reason was lack of efficacy and inadequate pain relief (38%), followed by lead failure (15%) and infection (14%). While SCS is generally effective, issues related to device longevity and patient satisfaction persist, with explantation rates due to technical failures and lack of efficacy being concerns.

Conclusion

SCS efficacy varies, with explantation rates reaching up to 38%, often due to inadequate pain relief. Most explantations occur within the first year, despite SCS being a safe and effective treatment. High implantation costs ($35,000 to $70,000) and revision costs ($15,000 to $25,000) raise concerns among payors. The hardware-driven model limits waveform flexibility, highlighting the need for innovation.

Functional Ultrasound Imaging Reveals Activation Properties of Clinical Spinal Cord Stimulation Therapy Programming

Objective

Spinal cord stimulation (SCS) therapy is an established treatment for chronic neuropathic pain, but methodological limitations have prohibited detailed investigation of activation patterns it produces in the SC. Functional ultrasound imaging (fUS) is an emerging technology that monitors local hemodynamic changes in the brain with high sensitivity and spatiotemporal resolution that are tightly coupled to neural functional activity. In this study, fUS was used to investigate neuromodulation patterns produced by clinical SCS paradigms in an ovine model that enabled testing with implanted clinical hardware.

Materials and Methods

Activation of local superficial dorsal horn (SDH) regions during SCS therapy was evaluated using fUS to detect hemodynamic changes in spinal blood volume (∆SBV). Standard SCS leads were percutaneously implanted midline overlying the dura of the exposed cord (T12-L1) to enable stimulation and recording evoked compound action potentials (eCAPs). Hemodynamic activation patterns were mapped across two vertebral segments at amplitudes between 100-200% eCAP threshold for conventional tonic, multiphase, burst, high frequency and multi-frequency SCS paradigms.

Results

SCS stimulation resulted in significant activation of the SDH in differing patterns across two vertebral segments. The magnitude and volume of ∆SBV increased at higher amplitudes and was typically maximal in the SDH regions underlying the active electrodes. Therapy mode significantly influenced total area and depth of ∆SBV. Multiphase therapy produced the largest area of ∆SBV followed by multi-frequency and other SCS modes. Multiphase therapy also produced the greatest depth of ∆SBV followed by multi-frequency and burst therapies.

Conclusion

This work demonstrates that fUS can effectively measure SCS neural response patterns in the pain processing laminae of a large animal model implanted with a clinical SCS system. Hemodynamic responses in the SC varied significantly across SCS therapy modes, with multiphase stimulation providing a greater area of coverage and depth of response versus other common stimulation types.

Cylindrical vs Paddle Leads in Spinal Cord Stimulation for the Long-term Treatment of Chronic Pain: A Systematic Review and Meta-analysis

OBJECTIVES

This systematic review compares the long-term efficacy of cylindrical-lead spinal cord stimulation (CL-SCS) vs paddle-lead spinal cord stimulation (Paddle-SCS) for chronic pain management.

MATERIALS AND METHODS

We included prospective and retrospective studies with at least ten patients reporting on the efficacy of either lead type. Primary outcomes were pain score reduction (measured by the visual analog scale [VAS] and numeric rating scale [NRS]) and 50% pain relief after at least 12 months. Secondary outcomes included functional disability and complications, such as lead migration and infection rates. Meta-analyses compared effect sizes, while meta-regression and subgroup analyses addressed heterogeneity.

RESULTS

A total of 96 studies, comprising 7726 patients, met the inclusion criteria. Paddle-SCS demonstrated superior pain reduction, with a standardized mean difference (SMD) of 5.37 (95% CI [5.35, 5.38]) compared with CL-SCS, which had an SMD of 4.09 (95% CI [4.08, 4.10]) on the VAS. However, CL-SCS outperformed Paddle-SCS on the NRS, with SMDs of 4.39 vs 2.35, respectively. For 50% pain relief, Paddle-SCS had a success rate of 41.4%, as opposed to 35.4% for CL-SCS. Paddle-SCS showed a lower migration rate (4.3% vs 7.2% for CL-SCS) but higher infection rates (5.0% vs 3.3%).

CONCLUSIONS

Paddle-SCS offers superior pain reduction (as measured by the VAS) and a lower migration rate, but a higher infection risk compared with CL-SCS. CL-SCS showed better outcomes as measured by the NRS. The choice between Paddle-SCS and CL-SCS should be individualized according to patient-specific factors and treatment goals. Further research with rigorous study designs is needed to provide clearer comparisons between these interventions.

A Review of the Prospera Spinal Cord Stimulation System with Multiphase Stimulation and Proactive Care

PURPOSE OF REVIEW

The purpose of this review is to describe the development and key features of the Prospera™ Spinal Cord Stimulation (SCS) System, as well as the clinical evidence supporting its use. Prospera delivers therapy using a proprietary multiphase stimulation paradigm and is the first SCS system to offer proactive care through automatic, objective, daily, remote device monitoring and remote programming capabilities.

RECENT FINDINGS

Results from the recently published BENEFIT-02 trial support the short-term safety and efficacy of multiphase stimulation in patients with chronic pain. BENEFIT-03 is an ongoing, multicenter, single-arm study with 24-month follow-up; interim analyses suggest that multiphase therapy is safe and effective and that patients and clinicians have positive experiences with remote device management. Preliminary evidence suggests that the Prospera SCS System represents an opportunity to improve patient care by combining an effective multiphase stimulation paradigm with an efficient proactive care model.

Spinal Cord Stimulation for Low Back Pain: A Systematic Review

PURPOSE OF REVIEW

Chronic low back pain (LBP) is a prevalent and debilitating condition affecting millions worldwide. Among emerging interventions, spinal cord stimulation (SCS) has gained attention as a potential alternative for managing chronic LBP, particularly when alternative approaches fail to provide adequate relief.

RECENT FINDINGS

This systematic review focuses on both residual pain levels and ability to perform daily tasks after treatment with SCS. The present investigation includes a systematic search for studies from PubMed, Google Scholar, and Cochrane, and Embase. Sources were eligible for inclusion in the review if they were published from 2010 to present (May 1, 2024). 8 studies involving a total of 1,172 patients were evaluated. This systematic review demonstrated that SCS is superior to conventional medical management (CMM) for both short and long-term pain relief, functionality, psychological well-being, and opioid dependency. Furthermore, newer SCS approaches, such as high frequency (HF), differential target multiplexed (DTM), and multiphase SCS all demonstrated improved efficacy over traditional SCS for pain relief and functionality scores. Adverse event rates for all trials were low and represent the safety of SCS treatments. The present investigation provides insight into the capabilities of both traditional SCS and HF SCS, DTM SCS, and multiphase SCS as compared to baseline pain and functionality as well as conventional medical management (CMM). This review grants physicians a broader picture of the applicability of SCS, its safety profile, and the opportunities it offers for pain reduction and functionality over CMM.

Pathophysiology of Pain and Mechanisms of Neuromodulation: A Narrative Review (A Neuron Project)

Pain serves as a vital innate defense mechanism that can significantly impact an individual's quality of life. Understanding the physiological effects of pain well plays an important role in developing novel pain treatments. Nociceptor neurons play a key role in pain and inflammation. Interactions between nociceptors and the immune system occur both at the site of injury and within the central nervous system. Modulating chemical mediators and nociceptor activity offers promising new approaches to pain management. Essentially, the sensory nervous system is essential for modulating the body's protective response, making it critical to understand these interactions to discover new pain treatment strategies. New innovations in neuromodulation have led to alternatives to opioids individuals with chronic pain with consequent improvement in disease-based treatment and nerve targeting. New neural targets from cellular and structural perspectives have revolutionized the field of neuromodulation. This narrative review aims to elucidate the mechanisms of pain transmission and processing, examine the characteristics and properties of nociceptors, and explore how the immune system influences pain perception. It further provides an updated overview of the physiology of pain and neuromodulatory mechanisms essential for managing acute and chronic pain. We assess the current understanding of different pain types, focusing on key molecules involved in each type and their physiological effects. Additionally, we compare painful and painless neuropathies and discuss the neuroimmune interactions involved in pain manifestation.

Current Waveforms in Spinal Cord Stimulation and Their Impact on the Future of Neuromodulation: A Scoping Review

BACKGROUND

Neuromodulation is a standard and well-accepted treatment for chronic refractory neuropathic pain. There has been progressive innovation in the field over the last decade, particularly in areas of spinal cord stimulation (SCS) and dorsal root ganglion stimulation. Improved outcomes using proprietary waveforms have become customary in the field, leading to an unprecedented expansion of these products and a plethora of options for the management of pain. Although advances in waveform technology have improved our fundamental understanding of neuromodulation, a scoping review describing new energy platforms and their associated clinical effects and outcomes is needed. The authors submit that understanding electrophysiological neuromodulation may be important for clinical decision-making and programming selection for personalized patient care.

OBJECTIVE

This review aims to characterize ways differences in mechanism of action and clinical outcomes of current spinal neuromodulation products may affect contemporary clinical decision-making while outlining a possible path for the future SCS.

STUDY DESIGN

The study is a scoping review of the literature about newer generation SCS waveforms.

MATERIALS AND METHODS

A literature report was performed on PubMed and chapters to include articles on spine neuromodulation mechanism of action and efficacy.

RESULTS

A total of 8469 studies were identified, 75 of which were included for the scoping review after keywords defining recent waveform technology were added.

CONCLUSIONS

Clinical data suggest that neuromodulation remains a promising tool in the treatment of chronic pain. The evidence for SCS for treating chronic pain seems compelling; however, more long-term and comparative data are needed for a comparison of waveforms when it comes to the etiology of pain. In addition, an exploration into combination waveform therapy and waveform cycling may be paramount for future clinical studies and the development of new technologies.