Evidence indicates that EES may promote functional recovery in patients with chronic incomplete SCI and in a subset of those clinically classified as having “motor-complete” SCI; however, its therapeutic benefit is influenced by the complex interaction of multiple factors, including the integrity of spared pathways, the level of injury, stimulation parameters, electrode configuration, and rehabilitation intensity.
Abstract
Lower extremity motor dysfunction after spinal cord injury (SCI) represents a major determinant of long-term disability and reduced quality of life. Although conventional pharmacotherapy and rehabilitation training may partially attenuate secondary injury and preserve residual function, their capacity to restore motor networks below the level of injury remains limited. In recent years, epidural electrical stimulation (EES), through targeted modulation of lumbosacral dorsal root afferents and local interneuronal circuits, has been shown to increase the excitability of spinal motor networks and augment residual descending input. Moreover, when integrated with task-specific training, EES has been associated with improvements in lower extremity motor functions, including standing, stepping, walking, and spasticity control. This study narratively reviews the pathophysiological basis of SCI, the neural mechanisms underlying EES, its clinical efficacy, combined therapeutic approaches, individualized parameter optimization, and current limitations. Available evidence, though currently limited by small sample sizes and study heterogeneity, indicates that EES may promote functional recovery in patients with chronic incomplete SCI and in a subset of those clinically classified as having “motor-complete” SCI; however, its therapeutic benefit is influenced by the complex interaction of multiple factors, including the integrity of spared pathways, the level of injury, stimulation parameters, electrode configuration, and rehabilitation intensity. Further progress is required, particularly in multicenter randomized controlled trials, standardized outcome assessments, closed-loop programming, and long-term safety evaluation, to support the translation of EES from an investigational neuromodulation strategy into a broadly applicable, precision-oriented rehabilitation modality.
Cervical spinal cord injury (CSCI) leads to severe impairment of the upper limb, which leads to tetraplegia and decreased independence in aspects of self-care and grasping. Conventional rehabilitation provides limited recovery, particularly in the case of complete American Spinal Injury Association (ASIA) Impairment Scale (AIS) A–B injuries, and there is a growing interest in multimodal rehabilitation strategies. This systematic review summarized evidence from 38 studies including pilot studies, preclinical investigations, and randomized controlled trials published between 2016 and 2026. Interventions were systematically classified and data extracted for the primary upper-limb outcomes, the Action Research Arm Test, grip strength, Graded Redefined Assessment of Strength, Sensibility and Prehension, Upper Extremity Motor Score, and Spinal Cord Independence Measure. About three-quarters of the studies reported improvements in at least one upper-limb outcome and almost half the studies had clinically meaningful improvements. However, 44% of studies were judged to have a high or critical risk of bias due to small sample sizes and limited controls; more than 90% reported no major safety concerns. Orthotic and robotic interventions maintained functional improvements, whereas hybrid neuromodulation approaches led to the largest gains in grip strength. Pharmacological therapies were of little benefit. In conclusion, multimodal non-invasive rehabilitation strategies might be promising for the improvement of upper-limb recovery after CSCI, but larger, high-quality clinical trials are needed.
Received: 24 March 2026 | Revised: 18 June 2026 | Accepted: 11 August 2026
Conflict of Interest
The authors declare that they have no conflicts of interest to this work.
Data Availability Statement
Data sharing is not applicable to this article as no new data were created or analyzed in this study.
Author Contribution Statement
Krishnakumar Sankar: Conceptualization, Methodology, Validation, Investigation, Resources, Data curation, Writing – original draft, Writing – review & editing, Visualization, Supervision, Project administration. Yazhini Arulselvam: Conceptualization, Investigation, Data curation, Writing – original draft, Writing – review & editing, Visualization. Supriya Harikrishna: Conceptualization, Investigation, Data curation, Writing – original draft, Writing – review & editing, Visualization.
This review catalogs recent conceptual and technological developments contributing to the emergence of brain-spine interfaces and suggests they may have potential to improve the quality of life for SCI patients.
Vijay Sivan, Zahin Alam, H. Polavarapu et al.· Neurosurgical review· 0 citations
Background Spinal cord injury (SCI) leads to significant motor and sensory impairments, reducing independence and quality of life. Conventional rehabilitation often lacks the intensity and task specificity required for optimal gait recovery. Powered lower-limb exoskeletons have emerged as a promising adjunct to enhance functional outcomes through repetitive, task-oriented training. Objective This meta-analysis aimed to evaluate the effectiveness and safety of exoskeleton-assisted rehabilitation compared with conventional therapy in improving walking ability, motor function, and activities of daily living in individuals with SCI. Methods A systematic search of PubMed, Embase, Cochrane Library, Scopus, Web of Science, CNKI, Wanfang, and VIP databases was conducted for studies published between January 2016 and December 2024. Ten controlled trials involving 412 participants were included. Primary outcomes were Berg Balance Scale (BBS), 6-Minute Walk Distance (6MWD), Lower Extremity Motor Score (LEMS), Walking Index for Spinal Cord Injury II (WISCI-II) and Modified Barthel Index (MBI). Data were pooled using fixed- or random-effects models based on heterogeneity. Results Exoskeleton-assisted rehabilitation significantly improved balance (BBS: MD 4.84, 95% CI 4.19–5.50; p < 0.001), walking endurance (6MWD: MD 31.09 m, 95% CI 27.25–34.93; p < 0.001), LEMS (MD 10.00, 95% CI 8.31–11.69; p < 0.001), gait independence (WISCI-II: MD 3.25, 95% CI 2.65–3.85; p < 0.001), and activities of daily living (MBI: MD 3.44, 95% CI 1.23–5.65; p = 0.003). Improvements were also observed in the ASIA lower-limb motor score (MD 7.28, 95% CI 6.44–8.12; p < 0.001). Substantial heterogeneity was present in some outcomes. No serious adverse events related to exoskeleton use were reported across the included studies. Conclusion Exoskeleton-assisted rehabilitation is associated with statistically significant improvements in balance, walking performance, motor function, and functional independence in individuals with SCI compared with conventional therapy.
Peishi Feng, Jinglong Li, Sheng Lu et al.· Frontiers in Neurorobotics· 0 citations
BACKGROUND
Upper extremity motor dysfunction is common after stroke. Based on the inter-hemispheric inhibition model, cathodal transcranial direct current stimulation (c-tDCS) applied over the contralesional primary motor cortex (M1) is a promising adjuvant neuromodulation, but high-quality evidence for its efficacy, optimal parameters, and safety remains limited.
METHODS
We searched 10 databases through January 25, 2026, for parallel randomized controlled trials (RCTs). Methodological quality was assessed using Cochrane Risk of Bias 2.0, and meta-analyses were performed using RevMan 5.4 and Stata/SE 15.1.
RESULTS
Twenty-six RCTs (1038 patients) were included. Compared with controls, c-tDCS significantly improved upper extremity motor function, manual dexterity, and daily living activities, while also reducing elbow spasticity and overall neurological impairment (all p < 0.05). Resting motor threshold remained unchanged. Subgroup analyses showed stable efficacy at 1-2 mA, 20 min/session, 5 sessions/week, and ≥2 weeks of treatment. Short-term benefits were preserved, while long-term durability needs verification. Adverse events were mild and transient, mainly local tingling and itching.
CONCLUSIONS
Adjuvant c-tDCS improves upper limb motor function, daily living activities, elbow spasticity, and global neurological status in stroke survivors, with favorable safety and short-term durability. A regimen of 1-2 mA for 20 min, 5 sessions/week for ≥2 weeks is recommended.
Jiangmei Chen, Liqiang Yu, Fang Liu et al.· Brain Injury· 0 citations
With the continuous development of artificial intelligence, novel biomaterials, and immersive technologies such as virtual reality, BCIs are expected to evolve toward more personalized, home-based, and intelligent rehabilitation solutions, accelerating their clinical application and offering new therapeutic hope for SCI patients.
Xudong Zhao, Keyi Chen, Jinquan Ma et al.· Spine Research· 0 citations
Background/Objectives: Spinal cord epidural stimulation (scES) holds significant potential for restoring autonomic function after chronic spinal cord injury (SCI). A significant and often debilitating sequela of SCI is neurogenic lower urinary tract dysfunction, characterized by loss of voluntary bladder control, which adversely impacts patients’ dignity, urological health, and overall quality of life. In a pilot study of three individuals with SCI, an epidural electrode array was implanted between L2 and sacral segments to modulate lower urinary tract function for efficient emptying. Methods: Three participants with chronic thoracic clinically complete SCI were implanted with an epidural stimulator over the lumbosacral spinal cord. Array placement was confirmed using intraoperative and postoperative spatiotemporal mapping of known motor neuron pools following published protocols. In a controlled laboratory mapping, bladder storage and voiding neural networks were targeted during filling cystometry by interactively optimizing lower urinary tract stimulation parameters (electrode configuration, frequency, intensity, and pulse width). Efficacy was assessed during six-hour laboratory sessions of natural bladder filling, followed by approximately four months of daily at-home use. Results: Pre-implant cystometry revealed poor voiding efficiency and absent bladder sensation. Following bladder scES mapping and home training, one of the three participants regained direct bladder sensation, exceeded the 90% clinical threshold for efficient voiding, and continues to use scES for bladder management instead of intermittent catheterization, with no urinary tract infections reported since completion of training (February 2022). The inability of two participants to attain high voiding efficiency may be due to suboptimal adherence to prescribed bladder training protocols in one case and the presence of an elevated bladder neck in the other. All three participants reported off-target improvements in bowel and sexual functions. Conclusions: The present novel pilot study provides the first evidence supporting the potential use of epidural stimulation for bladder management and the importance of activity-based recovery training for durable performance.
Charles H. Hubscher, Siqi Wang, T. Manning et al.· Journal of Clinical Medicine· 0 citations
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