Cervical spinal cord stimulation for Upper Limb Paralysis

Recent advances in cervical spinal cord stimulation (SCS) have demonstrated improved efficacy as a therapeutic intervention for restoring hand functions in individuals with spinal cord injury or stroke. Accumulating evidence consistently shows that cervical SCS yields significant improvements in grip force, proximal arm strength, and muscle activation, with immediate and sustained effects. This review synthesizes the evidence that electrical stimulations modulate the spinal and supraspinal organization of uninjured descending motor tracts, primarily the residual corticospinal tract, reticulospinal tract, and propriospinal network of neurons, as well as increasing the sensitivity of spinal interneurons at the stimulated segments to these inputs. Additionally, we examine contemporary strategies to achieve more precise patterned stimulations, including intraspinal microstimulation, ventral cord stimulation, and closed-loop neuromodulation. They discuss the potential benefits of incorporating cervical SCS into a multimodal treatment paradigm. Level of evidence: V ¹⁾

The review presents a compelling case for the efficacy of cervical SCS in restoring hand function post-SCI and stroke, backed by emerging mechanistic and clinical evidence. However, its reliance on lower-level evidence, insufficient discussion of patient variability, and limited coverage of potential risks necessitate further scrutiny. Future research should focus on controlled clinical trials, personalized stimulation paradigms, and long-term outcome assessments to fully establish the role of cervical SCS in neurorehabilitation. Despite these limitations, the ongoing advancements in stimulation strategies suggest a promising trajectory for this intervention in motor recovery.