Combining tsDCS and Exoskeleton Gait Training on Spinal Excitability in SCI

Impact of Combining tsDCS and Robotic Exoskeleton Gait Training on Spinal Excitability and Gait Function in Individuals With SCI

The purpose of the study is to determine whether transcutaneous spinal direct current stimulation (tsDCS) is safe for individuals with spinal cord injury (SCI). tsDCS is an electrical current applied to the skin. The plan is to also study the potential neurophysiological changes (changes in speed and excitability of the nerves) and functional improvements in gait (for example, gait quality, speed and walking distance) for individuals with SCI after combined application of tsDCS and exoskeleton assisted gait training.

Subjects will participate in two baseline visits, 4 days apart. Each baseline visit will last 1 hour and will include assessment of soleus H-Reflex and 10 meter walk test on arrival and 40 minutes after the initial assessment. Subjects will be asked to minimize their activity between assessments by either sitting in a chair or lying on a mat.

Each training visit will involve either an exoskeleton intervention or a combined exoskeleton and tsDCS intervention. Each training visit will include assessment of soleus H-Reflex and 10 meter walk test before and after the exoskeleton intervention or before and after the combined exoskeleton and tsDCS intervention.

Inclusion Criteria:

• Male or non-pregnant female
• ≥18 years of age
• Able to achieve adequate fit within exoskeleton
• Diagnosis of spinal cord injury (SCI), T10 level and above (T11 and 12 may participate if no clinical signs of lower motor neuron lesion present)
• Minimum of 6 months post injury
• Sufficient range of motion to attain normal, reciprocal gait pattern, and transition from normal sit to stand or stand to sit
• Weight <220 pounds
• Intact skin on all surfaces in contact with device and load bearing surfaces
• Ability to perform informed consent

Exclusion Criteria:

• Pregnancy
• Spinal instability
• Unhealed limb or pelvic fractures or any condition restricting weight bearing in limbs
• Presence of peripheral neuropathy or any pathology that could influence reflex excitability
• Diagnosis of other neurological injury other than SCI such as stroke/cerebrovascular accident (CVA), multiple sclerosis (MS), acquired brain injury (ABI), cerebral palsy (CP)
• Uncontrolled spasticity (≥3 on Modified Ashworth Scale)
• Colostomy
• Decreased range of motion or contractures in legs (>10° at hips, knees or ankles)
• Uncontrolled autonomic dysreflexia
• Unresolved deep vein thrombosis
• Inability to tolerate standing due to cardiovascular issues or orthostatic hypotension
• Severe comorbidities: active infections, heart, lung, or circulatory conditions
• Pressure sores, impaired skin integrity
• Use of mechanical ventilation for respiratory support
• Presence of any of the following contraindications to electrical stimulation: cardiac pacemaker, deep brain stimulator, or evidence of cancerous (malignant) tissue
• Presence of metal in thoracic spine or region of electrode placement