Enhancing Corticospinal Activation for Improved Walking Function

For many people with spinal cord injury (SCI), the goal of walking is a high priority. There
are many approaches available to restore walking function after SCI; however, these
approaches often involve access to intensive training programs, facilities, qualified staff,
and advanced technology that make practicing walking at home difficult. For this reason,
developing training approaches that could be easily performed in the home would be of great
value. In addition, research suggests that enhancing brain excitability might have benefits
for improving the communication between the brain and spinal cord. Transcranial direct
current stimulation (tDCS) is a type of non-invasive brain stimulation that has been shown to
directly increase brain excitability, which may make it easier for the brain and nervous
system to respond to training. Combining motor skill exercises with brain stimulation may
enhance the restoration of walking function in persons with SCI. Based on these findings, the
primary aim of this proof-of-concept study is to inform future intervention development. To
meet this aim, we will determine if moderate-intensity, motor skill training can improve
walking-related outcomes among persons with SCI and to determine if the addition of
non-invasive brain stimulation will result in greater improvements in function compared to
training alone.

Participants in the proposed study will complete one baseline testing session, 3 motor
training sessions, and one follow-up session over 5 consecutive days. During the first and
fifth sessions, participants will complete assessments only, which will take approximately
2-3 hours each day. During the second, third, and fourth sessions, participants will perform
a series of 6 standing motor skill exercises designed to challenge balance, lower extremity
coordination, agility, and speed. Participants will be randomized to either a motor training
only group or a motor training + tDCS group. The motor training + tDCS group will receive
brain stimulation during the motor skill training, while the motor training only group will
receive sensory level brain stimulation only. Each participant will complete the 6 motor
skill exercise circuit 4 times. Motor training exercise sessions will last approximately
25-30 minutes and will be preceded and followed by assessments of walking function,
spasticity, and ankle strength in order to determine changes in these measures over time.

Inclusion Criteria:

- Have a spinal cord injury (neurological level C3-T10);

- Chronic SCI (12 months or greater);

- Neurological impairment classification C or D;

- Able to stand for at least 5 minutes (with or without an assistive device);

- Able to move each leg independently for at least 3 steps;

- Able to rise from sit to stand with moderate assistance from one person;

- Ability and willingness to consent and authorize use of personal health information.

Exclusion Criteria:

- Progressive spinal lesions including degenerative, or progressive vascular disorders
of the spine and/or spinal cord;

- Injuries below the neurological spinal level of T10;

- History of cardiovascular irregularities;

- Altered cognitive status;

- Presence of orthopedic conditions that would adversely affect participation in
exercise;

- Implanted metallic objects in the head;

- History of seizures;

- Inability and unwillingness to consent and authorize use of personal health
information.