Cervical Spinal Cord Transcutaneous Stimulation Improves Upper Extremity and Hand Function in People With Complete Tetraplegia: A Case Study

Recovery of the upper extremity (UE) and hand function is considered the highest priority for people with tetraplegia, because these functions closely integrate with their activities of daily living. Spinal cord transcutaneous stimulation (scTS) has great potential to facilitate functional restoration of paralyzed limbs by neuro-modulating the excitability of the spinal network. Recently, this approach has been demonstrated effective in improving UE function in people with motor complete and incomplete cervical SCI. However, the research thus far is limited by the lack of a comprehensive assessment of functional improvement and neurological recovery throughout the intervention. The goal of this study was to investigate whether scTS can also facilitate UE functional restoration in an individual with motor and sensory complete tetraplegia. A 38-year-old male with a C5 level, ASIA Impairment Scale-A SCI (15 years post-injury, left hand dominant pre- and post-injury), received 18 sessions (60 minutes/session) of scTS combined with task-specific hand training over the course of 8 weeks. The total score of the Graded Redefined Assessment of Strength, Sensibility, and Prehension significantly improved from 72/232 to 96/232 at post-intervention, and maintained ranging from 82/232 to 86/232 during the three months follow-up without any further treatment. The bilateral handgrip force improved by 283.4% (left) and 30.7% (right), respectively at post-intervention. These strength gains were sustained at 233.5% -250% (left) and 11.5%-73.1% (right) during the follow-up evaluation visits. Neuromuscular Recovery Scale demonstrated dramatic and long-lasting improvements following the completion of the intervention. Changes of spinal motor evoked potentials from pre- to post-intervention indicated an increased level of spinal network excitability. The present data offer preliminary evidence that the novel scTS intervention combined with hand training can enhance UE functional use in people with motor and sensory complete SCI.