Effects of Transvertebral Direct Current Stimulation in Humans

Effects of Transvertebral Direct Current Stimulation in Humans

This study will evaluate the effects of non-invasive stimulation of the spinal cord in people with spinal cord injury.

This study will use a non-invasive form of spinal stimulation, called transvertebral direct current stimulation, or tvDCS. It currently is not clear what effects this type of stimulation has on the excitability of the brain and spinal cord in people with spinal cord injury. In this study, subjects will participate in 3 sessions, with at least 1 week in between sessions, during which they will get a different condition of tvDCS. We will test the excitability of the brain and spinal cord before and after tvDCS in each session.

Inclusion Criteria:

• 18 to 65 years of age
• Motor incomplete spinal cord injury classified as B, C, or D by the American Spinal Injury Association Impairment Scale (AIS)
• More than 12 months post-injury
• Lesion at of above thoracic level T8
• Body mass index <30 (in order to facilitate reliable location of body landmarks guiding stimulation)
• Severe gait deficit

Exclusion Criteria:

• Unstable cardiopulmonary conditions
• History of seizure, head injury with loss of consciousness, severe alcohol or drug abuse, and/or psychiatric illness
• Cognitive deficits severe enough to preclude informed consent
• Positive pregnancy test of being of childbearing age and not using appropriate contraception
• Ferromagnetic material in the brain or in the spine (except for titanium for segmental fixation of the spine)
• Cardiac or neural pacemakers
• Fixed contractures in the lower extremities
• Uncontrolled diabetes
• Severe osteoporosis
• Severe spasticity
• Decubitus ulcers which interfere with harness support or walking
• Severe orthostatic hypotension