Abstract
Study design
Feasibility study, consisting of random-order, cross-over study of a single intervention session, followed by a parallel-arm study of 16 sessions.
Objectives
To investigate the feasibility of a novel combinatorial approach with simultaneous delivery of transcutaneous spinal direct current stimulation (tsDCS) and locomotor training (tsDCS + LT) after spinal cord injury, compared to sham stimulation and locomotor training (sham + LT), and examine preliminary effects on walking function.
Setting
Clinical research center in the southeastern United States.
Methods
Eight individuals with chronic incomplete spinal cord injury (ISCI) completed the two-part protocol. Feasibility was assessed based on safety (adverse responses), tolerability (pain, spasticity, skin integrity), and protocol achievement (session duration, intensity). Walking function was assessed with the 10 m and 6 min walk tests.
Results
There were no major adverse responses. Minimal reports of skin irritation and musculoskeletal pain were consistent between groups. Average training peak heart rate as percent of maximum (mean(SD); tsDCS + LT: 66 (4)%, sham + LT: 69 (10)%) and Borg ratings of perceived exertion (tsDCS + LT: 17.5 (1.2), sham + LT: 14.4 (1.8)) indicate both groups trained at high intensities. Walking speed gains exceeded the minimal clinically important difference (MCID) in three of four who received tsDCS + LT (0.18 (0.29) m/s) and one of four in sham + LT (−0.05 (0.23) m/s). Gains in walking endurance exceeded the MCID in one of four in each group (tsDCS + LT: 36.4 (69.0) m, sham + LT: 4.9 (56.9) m).
Conclusions
Combinatorial tsDCS and locomotor training is safe and feasible for individuals with chronic ISCI, even those with considerable walking impairment. Study outcomes support the need to investigate the efficacy of this approach.
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Data availability
The datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request.
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Acknowledgements
The authors would like to acknowledge the participants and their families for their time and dedication to SCI rehabilitation research.
Funding
This work was supported by the REACT Center of NIH/NICHD [RFA-HD-15-010], Brooks-PHHP Research Collaboration, the NIH National Center for Medical Rehabilitation Research T32 Neuromuscular Plasticity Training Program [grant number T32HDO43730] and the NIH/NICHD K12 Rehabilitation Research Career Development Program [grant number HDO55929].
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DDF, DJC, and EJF conceived and designed the study. KAH, LAD, AV, HJS, CC, CW, GT, and EJF collected the data. KAH, LAD, HJS, and EJF performed the analysis and interpretation. KAH and EJF drafted the article. KAH, LAD, AV, HJS, CC, CW, GT, DDF, DJC, and EJF critically reviewed the draft and provided revisions. KAH, LAD, AV, HJS, CC, CW, GT, DDF, DJC, and EJF approved the final version to be published.
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The Institutional Review Board at the University of Florida approved the study (201801582) and all research was performed in accordance with the Declaration of Helsinki. We certify that all applicable institutional and governmental regulations concerning the ethical use of human volunteers were followed during the course of this research.
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Hawkins, K.A., DeMark, L.A., Vistamehr, A. et al. Feasibility of transcutaneous spinal direct current stimulation combined with locomotor training after spinal cord injury. Spinal Cord 60, 971–977 (2022). https://doi.org/10.1038/s41393-022-00801-1
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DOI: https://doi.org/10.1038/s41393-022-00801-1
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