Durability of Evoked Compound Action Potential (ECAP)-Controlled, Closed-Loop Spinal Cord Stimulation (SCS) in a Real-World European Chronic Pain Population

Transforming Chronic Pain Management: Integrating Neuromodulation with Advanced Technologies to Tackle Cognitive Dysfunction - A Narrative Review

Chronic pain is a complex and multidimensional condition that disrupts both physical function and cognitive processing, creating a bidirectional cycle that amplifies symptom burden and complicates clinical management. Cognitive dysfunction, characterized by deficits in memory, attention, and executive function, further impairs treatment adherence and functional recovery. Conventional pharmacologic therapies frequently fail to address this dual burden and are associated with adverse effects, including dependence and cognitive impairment. Neuromodulation has emerged as a promising nonpharmacologic alternative, capable of modulating neuroplastic, neuroinflammatory, and neurotransmitter pathways implicated in both pain and cognitive decline. This narrative review examines the mechanisms and clinical applications of spinal cord stimulation (SCS), transcutaneous electrical nerve stimulation (TENS), and neuromuscular electrical stimulation (NMES), and evaluates emerging innovations such as EcoAI™, an artificial intelligence-driven, non-invasive neuromodulation platform. By integrating physiological and behavioral biomarkers with real-time adaptive therapy, EcoAI and similar technologies represent a shift toward personalized, precision-based interventions. Additional advances in remote patient monitoring (RPM) and closed-loop feedback systems further enhance therapeutic responsiveness and continuity of care. Collectively, these approaches offer a scalable, patient-centered framework for managing chronic pain and its cognitive comorbidities. Future priorities include the development of validated biomarkers, rigorous clinical evaluation of AI-integrated systems, and equitable implementation strategies to ensure broad access to next-generation neuromodulation.

Closed-Loop Spinal Cord Stimulation in Chronic Pain Management: Mechanisms, Clinical Evidence, and Emerging Perspectives

Background: Chronic pain remains a major clinical challenge, which is often resistant to conventional treatments. Spinal cord stimulation has been used for decades to manage refractory pain, traditionally relying on open-loop systems with fixed-output stimulation. However, these systems fail to account for physiological variability, leading to inconsistent pain relief. Closed-loop spinal cord stimulation represents a significant advancement by utilizing evoked compound action potentials to continuously modulate stimulation intensity in real-time, ensuring more stable and effective pain management. Methods: A comprehensive literature review was conducted using PubMed and ClinicalTrials.gov to identify and synthesize relevant published and ongoing studies with a focus on open-loop spinal cord stimulation for managing lower back pain. Results: Clinical trials, including the Avalon and Evoke studies, have demonstrated that closed-loop spinal cord stimulation provides superior pain relief, functional improvement, and reduced opioid dependence compared to traditional open-loop systems. Patients receiving closed-loop stimulation reported significantly higher rates of sustained pain reduction, improved quality of life, and fewer complications related to overstimulation. Emerging studies suggest its potential for conditions beyond back pain, such as neuropathic pain, cancer-related pain, and Raynaud's phenomenon. Furthermore, cost-effectiveness analyses indicate that closed-loop spinal cord stimulation is a more economically viable treatment option compared to conventional medical management and open-loop systems. Conclusions: Closed-loop spinal cord stimulation represents a transformative development in neuromodulation, offering personalized and adaptive pain management that is distinct from open-loop spinal cord stimulation. Further research is warranted to explore its long-term durability, broader applications, and integration with emerging technologies in pain management.

Research hotspots and frontiers of neuromodulation technology in the last decade: a visualization analysis based on the Web of Science database

Background

Since the 1990s, neuromodulation technology has experienced rapid advancements, providing new therapeutic approaches for clinical rehabilitation in neurological disorders. The objective of this study is to utilize CiteSpace and VOSviewer to investigate the current research status, key topics, and future trends in the field of neuromodulation technology over the past decade.

Methods

Relevant literature in the field of neuromodulation technology published in Web of Science database from January 1, 2014 to June 18, 2024 were retrieved, and imported into CiteSpace and VOSviewer for visualization. VOSviewer was used for counties, institutions, authors and keywords analyses. CiteSpace was used for presentation visualization analysis of co-cited references, keywords clusters and bursts.

Results

This study encompasses a total of 1,348 relevant publications, with the number of publications showing an increasing trend year by year. The most significant growth was observed between 2020 and 2021. The United States, China and the United Kingdom are the three leading countries with high output in this regard. The top three institutions in terms of the publication volume are Harvard Medical School, the University of Toronto and Stanford University. Keyword co-occurrence and cluster analysis identified that deep brain stimulation, transcranial magnetic stimulation, transcranial direct current stimulation, and focused ultrasound stimulation are the most widely used central nerve stimulation techniques in neuromodulation. The treatment of intractable chronic pain also emerged as a key focus within neuromodulation techniques. The recent keywords bursts included terms such as recovery, movement, nucleus, modeling and plasticity, suggesting that the future research trend will be centered on these areas.

Conclusion

In conclusion, neuromodulation technology is garnering increasing attention from researchers and is currently widely used in brain diseases. Future research is expected to delve deeper, particularly into exploring deep brain structure stimulation targets and restoring motor function based on neuroplasticity theory.

Is There a Correlation Between Objective Measurement Tools and Self-Reporting Questionnaires To Evaluate Physical Activity and Health Status in Patients With Persistent Spinal Pain Syndrome Type 2 Before and After Spinal Cord Stimulation? Outcomes of a Feasibility Study

INTRODUCTION

The effect of spinal cord stimulation (SCS) on physical activity in patients with persistent spinal pain syndrome (PSPS) type 2 is commonly evaluated with standardized, validated self-reporting questionnaires. However, questionnaires are susceptible to subjective bias and may not align with objective data.

OBJECTIVE

We investigated the correlation among objective measurement devices, the Oswestry Disability Index (ODI), and patient's health status regarding physical activity in patients with PSPS type 2 receiving SCS.

MATERIALS AND METHODS

Alongside the ODI, we used an activity tracker to objectively measure physical activity and a neurostimulator device to objectively measure body positions at baseline and three-month follow-up. In addition, health status was measured using the positive model of health.

RESULTS

We included 20 patients, of whom 17 completed the three-month follow-up period. At three months follow-up, we found a significant correlation between the activity tracker's steps (r = -0.636, p = 0.006) and distance per day (r = -0.649, p = 0.005) with the ODI and a significant correlation of the neurostimulator's mobile position with the ODI (r = -0.497, p = 0.043). Furthermore, the activity tracker showed a significant increase in strenuous physical activity at three-month follow-up (p = 0.039). We also observed a substantial improvement across the domains of bodily function, social and societal participation, and daily functioning of the positive model of health.

CONCLUSIONS

This study showed significant correlations among objective measurement devices, the ODI, and health status, which could contribute to a more holistic approach to evaluating the effect of SCS. Prospective powered studies with a control group are needed to better understand this area.

CLINICAL TRIAL REGISTRATION

The protocol was registered in the Dutch Trial Register (NTR) on March 13, 2021 under registration number NL 9301 (number NL-OMON21829).