Feasibility and utility of transcutaneous spinal cord stimulation combined with walking-based therapy for people with motor incomplete spinal cord injury

Study design: Prospective case series. Objectives: To evaluate the feasibility and preliminary efficacy of combining transcutaneous spinal cord stimulation (TSCS) with walking-based physical therapy. Setting: Hospital-based outpatient center in Maryland, United States. Methods: Ten individuals with chronic (>1 year) motor incomplete spinal cord injury (iSCI) completed 23 sessions of 2-h therapy over 8 weeks. TSCS was delivered for the first 30 min of each session using a clinically available device with adjustable current. To assess feasibility of the intervention, we tracked pain, adverse events, and participant retention. Preliminary efficacy was assessed by evaluating changes in walking speed, endurance, and quality following the intervention with select functional outcome measures (10-m walk test (10MWT), 6-min walk test (6MWT), timed up and go, and walking index for spinal cord injury II). Results: We found that the combined intervention was feasible in an outpatient clinical setting. Participants tolerated the TSCS well, with no reports of significant adverse events or other issues (e.g., skin irritation or pain that disrupted training). None of the participants elected to discontinue the study. Participants also showed significant improvements in each measure of walking function following the intervention. Changes in walking speed, as measured by the 10MWT (0.56 ± 0.29 m/s to 0.72 ± 0.36 m/s), exceeded the minimal clinically important difference for individuals with iSCI. Changes in walking quality and endurance, as measured by the 6MWT (149.88 ± 99.87 m to 194.53 ± 106.56 m), exceeded the minimal detectable change for individuals with iSCI. Conclusions: These results indicate that TSCS is clinically feasible and may be useful as an adjunct to walking-based therapy for adults with iSCI.