Spinal Cord Stimulation for Functional Restoration in Spinal Cord Injury: A Narrative Review

Abstract

Spinal cord injury (SCI) represents a significant medical challenge, leading to profound and often debilitating neurological deficits that adversely affect motor, sensory, and autonomic functions. Traditional rehabilitation strategies, while essential in the management of SCI, often exhibit limited efficacy in restoring lost functions, leaving many individuals with permanent disabilities. In this context, spinal cord stimulation (SCS) emerges as a novel and promising therapeutic approach with the potential to enhance neurological recovery by promoting neural plasticity and activating residual neural pathways. This narrative review provides a comprehensive examination of SCS, elucidating its underlying mechanisms of action, technological advancements, clinical applications, and associated outcomes in patients with SCI. Both invasive (epidural) and noninvasive (transcutaneous) SCS are discussed, emphasizing their therapeutic potentials with current established evidence. This narrative review integrates findings from preclinical and clinical studies, highlighting the role of SCS in facilitating functional recovery. Furthermore, this review highlights the challenges faced in the field, including variability in patient responses, lack of standardized stimulation protocols, and the need for further research to substantiate long-term outcomes. We conclude by discussing future directions for SCS research, including the development of closed-loop systems and innovative brain-spine interfaces, which may optimize treatment delivery and enhance functional recovery in individuals with SCI.

Keywords: clinical applications; neural plasticity; neuromodulation; spinal cord injuries; spinal cord stimulation.

Figure 1. Mechanisms of action in SCS

SCS: spinal cord stimulation; SCI: spinal cord injury The proposed mechanisms of SCS in SCI include (1) enhancement of monosynaptic reflex activation, (2) reorganization of spinal networks, and (3) strengthening response to supraspinal inputs (this figure was produced by the authors)