Effects of Transvertebral Direct Current Stimulation in Humans

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

Detailed Description
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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.

Official Title
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Effects of Transvertebral Direct Current Stimulation in Humans

Conditions
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Spinal Cord Injuries, Paraplegia and Tetraplegia

Intervention / Treatment
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* Device: transvertebral direct current stimulation (tvDCS)


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Anodal tvDCS<br>20 minutes of anodal tvDCS will be applied over the spine at 2.5mA. | Device: transvertebral direct current stimulation (tvDCS)<br>* tvDCS is a painless, non-invasive form of spinal stimulation which delivers safe, low levels of electrical current to the spinal cord through the back. It is believed to be able to influence the excitability of the brain and spinal cord.<br>|
| Experimental: Cathodal tvDCS<br>20 minutes of cathodal tvDCS will be applied over the spine at 2.5mA. | Device: transvertebral direct current stimulation (tvDCS)<br>* tvDCS is a painless, non-invasive form of spinal stimulation which delivers safe, low levels of electrical current to the spinal cord through the back. It is believed to be able to influence the excitability of the brain and spinal cord.<br>|
| Sham Comparator: Sham tvDCS<br>20 minutes of sham tvDCS will be applied over the spine. | Device: transvertebral direct current stimulation (tvDCS)<br>* tvDCS is a painless, non-invasive form of spinal stimulation which delivers safe, low levels of electrical current to the spinal cord through the back. It is believed to be able to influence the excitability of the brain and spinal cord.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in corticospinal excitability | This will be measured using transcranial magnetic stimulation to evoke responses in muscles of the lower leg. | Immediately before tvDCS, Immediately after tvDCS | 
| Change in spinal cord excitability | Hoffmann's reflex will be used to assess spinal cord excitability. For this text, pulses of electrical stimulation will be applied to the back of the knee and the response will be measured from the calf muscle. | Immediately before tvDCS, Immediately after tvDCS | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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neuroplasticity, transvertebral direct current stimulation, transspinal direct current stimulation