Transvertebral direct current stimulation paired with locomotor training in chronic spinal cord injury: A case study

STUDY DESIGN: This double-blind, sham-controlled, crossover case study combined transvertebral direct current stimulation (tvDCS) and locomotor training on a robot-assisted gait orthosis (LT-RGO). OBJECTIVE: Determine whether cathodal tvDCS paired with LT-RGO leads to greater changes in function and neuroplasticity than sham tvDCS paired with LT-RGO. SETTING: University of Kentucky (UK) HealthCare Stroke and Spinal Cord Neurorehabilitation Research at HealthSouth Cardinal Hill Hospital. METHODS: A single subject with motor incomplete spinal cord injury (SCI) participated in 24 sessions of sham tvDCS paired with LT-RGO before crossover to 24 sessions of cathodal tvDCS paired with LT-RGO. Functional outcomes were measured with 10 Meter Walk Test (10MWT), 6 Minute Walk Test (6MWT), Spinal Cord Independence Measure-III (SCIM-III) mobility component, lower extremity manual muscle test (MMT), and Berg Balance Scale (BBS). Corticospinal changes were assessed using transcranial magnetic stimulation. RESULTS: Improvement in 10MWT speed, SCIM-III mobility component, and BBS occurred with both conditions. 6MWT worsened after sham tvDCS and improved after cathodal tvDCS. MMT scores for both lower extremities improved following sham tvDCS but decreased following cathodal tvDCS. Corticospinal excitability increased following cathodal tvDCS but not sham tvDCS. CONCLUSION: These results suggest that combining cathodal tvDCS and LT-RGO may improve functional outcomes, increase corticospinal excitability, and possibly decrease spasticity. Randomized controlled trials are needed to confirm these conclusions.