Combining tsDCS and Exoskeleton Gait Training on Spinal Excitability in SCI

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

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

Conditions
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Spinal Cord Injury

Intervention / Treatment
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* Device: cathode tsDCS
* Device: Ekso
* Device: anode tsDCS


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: no intervention; then no intervention; then cathode tsDCS + Ekso; then Ekso; then cathode tsDCS+Ekso<br>Non-invasive transcutaneous spinal direct current stimulation (tsDCS) applies electrical current to the spinal cord via surface electrodes placed on the skin. Ekso is a type of wearable robotic exoskeleton that provides support to an individual with lower extremity paralysis for standing and walking. Cathode tsDCS + Ekso will combine the use of cathode tsDCS application followed by a walking session in Ekso. Ekso will consist of a walking session in Ekso with no tsDCS. | Device: cathode tsDCS<br>* Non-invasive electrical stimulation, transcutaneous spinal direct current stimulation (tsDCS) is the application of electrical current to the spinal cord via surface electrodes placed on the skin.<br>Device: Ekso<br>* Ekso is a type of wearable robotic exoskeleton that provides support to an individual with lower extremity paralysis for standing and walking.<br>|
| Experimental: no intervention; then no intervention; then Ekso; then cathode tsDCS + Ekso; then Ekso<br>Non-invasive transcutaneous spinal direct current stimulation (tsDCS) applies electrical current to the spinal cord via surface electrodes placed on the skin. Ekso is a type of wearable robotic exoskeleton that provides support to an individual with lower extremity paralysis for standing and walking. Cathode tsDCS + Ekso will combine the use of cathode tsDCS application followed by a walking session in Ekso. Ekso will consist of a walking session in Ekso with no tsDCS. | Device: cathode tsDCS<br>* Non-invasive electrical stimulation, transcutaneous spinal direct current stimulation (tsDCS) is the application of electrical current to the spinal cord via surface electrodes placed on the skin.<br>Device: Ekso<br>* Ekso is a type of wearable robotic exoskeleton that provides support to an individual with lower extremity paralysis for standing and walking.<br>|
| Experimental: no intervention; then no intervention; then anode tsDCS + Ekso; then Ekso; then anode tsDCS + Ekso<br>Non-invasive transcutaneous spinal direct current stimulation (tsDCS) applies electrical current to the spinal cord via surface electrodes placed on the skin. Ekso is a type of wearable robotic exoskeleton that provides support to an individual with lower extremity paralysis for standing and walking. Anode tsDCS + Ekso will combine the use of anode tsDCS application followed by a walking session in Ekso. Ekso will consist of a walking session in Ekso with no tsDCS. | Device: Ekso<br>* Ekso is a type of wearable robotic exoskeleton that provides support to an individual with lower extremity paralysis for standing and walking.<br>Device: anode tsDCS<br>* Non-invasive electrical stimulation, transcutaneous spinal direct current stimulation (tsDCS) is the application of electrical current to the spinal cord via surface electrodes placed on the skin.<br>|
| Experimental: no intervention; then no intervention; then Ekso; then anode tsDCS + Ekso; then Ekso<br>Non-invasive transcutaneous spinal direct current stimulation (tsDCS) applies electrical current to the spinal cord via surface electrodes placed on the skin. Ekso is a type of wearable robotic exoskeleton that provides support to an individual with lower extremity paralysis for standing and walking. Anode tsDCS + Ekso will combine the use of anode tsDCS application followed by a walking session in Ekso. Ekso will consist of a walking session in Ekso with no tsDCS. | Device: Ekso<br>* Ekso is a type of wearable robotic exoskeleton that provides support to an individual with lower extremity paralysis for standing and walking.<br>Device: anode tsDCS<br>* Non-invasive electrical stimulation, transcutaneous spinal direct current stimulation (tsDCS) is the application of electrical current to the spinal cord via surface electrodes placed on the skin.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Spinal Cord Excitability as Measured by Percent Change in Soleus H-Reflex From Beginning of Session to End of the Same Session | This visit includes assessment of soleus H-Reflex on arrival and 40 minutes after the initial assessment--change between these two readings is reported. Subjects will be asked to minimize their activity between the two assessments by either sitting in a chair or lying on a mat. The H-reflex is a reaction of muscles after electrical stimulation (this stimulation is not the intervention, but is instead part of the H-reflex assessment). H-reflex will be elicited by placing the cathode of an electrical stimulator in the popliteal fossa (a shallow depression located at the back of the knee joint) and stimulating the tibial nerve. To record the electrical-induced muscle activity (that is, to measure H-reflexes), surface electromyography electrodes will be placed at the soleus muscle of the testing leg. | beginning and end of first no-intervention visit (7 days before any intervention) | 
| Change in Spinal Cord Excitability as Assessed by Percent Change in Soleus H-Reflex From Beginning of Session to End of the Same Session | This visit includes assessment of soleus H-Reflex on arrival and 40 minutes after the initial assessment--change between these two readings is reported. Subjects will be asked to minimize their activity between the two assessments by either sitting in a chair or lying on a mat. The H-reflex is a reaction of muscles after electrical stimulation (this stimulation is not the intervention, but is instead part of the H-reflex assessment). H-reflex will be elicited by placing the cathode of an electrical stimulator in the popliteal fossa (a shallow depression located at the back of the knee joint) and stimulating the tibial nerve. To record the electrical-induced muscle activity (that is, to measure H-reflexes), surface electromyography electrodes will be placed at the soleus muscle of the testing leg. | beginning and end of second no-intervention visit (3 days before any intervention) | 
| Change in Spinal Cord Excitability as Assessed by Percent Change in Soleus H-Reflex From Beginning of Session to End of the Same Session | Soleus H-Reflex is assessed on arrival and then after the intervention is applied--change between these two readings is reported. The H-reflex is a reaction of muscles after electrical stimulation (this stimulation is not the intervention, but is instead part of the H-reflex assessment). H-reflex will be elicited by placing the cathode of an electrical stimulator in the popliteal fossa (a shallow depression located at the back of the knee joint) and stimulating the tibial nerve. To record the electrical-induced muscle activity (that is, to measure H-reflexes), surface electromyography electrodes will be placed at the soleus muscle of the testing leg. | before and after intervention on day 1 | 
| Change in Spinal Cord Excitability as Assessed by Percent Change in Soleus H-Reflex From Beginning of Session to End of the Same Session | Soleus H-Reflex is assessed on arrival and then after the intervention is applied--change between these two readings is reported. The H-reflex is a reaction of muscles after electrical stimulation (this stimulation is not the intervention, but is instead part of the H-reflex assessment). H-reflex will be elicited by placing the cathode of an electrical stimulator in the popliteal fossa (a shallow depression located at the back of the knee joint) and stimulating the tibial nerve. To record the electrical-induced muscle activity (that is, to measure H-reflexes), surface electromyography electrodes will be placed at the soleus muscle of the testing leg. | before and after intervention on day 5 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gait Speed as Assessed by 10 Meter Walk Test | The 10 Meter Walk Test (10MWT) will assess subject's gait speed. Four marks will be placed on the ground at 0, 2, 12 and 14 meters. Subjects will walk a total of 14 meters. The middle 10 meters (between marks at 2 and 12 meters) will be timed and recorded as their gait speed. | first no-intervention visit (7 days before any intervention) | 
| Gait Speed as Assessed by 10 Meter Walk Test | The 10 Meter Walk Test (10MWT) will assess subject's gait speed. Four marks will be placed on the ground at 0, 2, 12 and 14 meters. Subjects will walk a total of 14 meters. The middle 10 meters (between marks at 2 and 12 meters) will be timed and recorded as their gait speed. | second no-intervention visit (3 days before any intervention) | 
| Gait Speed as Assessed by 10 Meter Walk Test | Subjects will undergo a walking session with Ekso, Ekso will then be removed, and subjects will then perform a 10 Meter Walk Test (10MWT) without use of Ekso exoskeleton. The 10MWT will assess subject's gait speed. Four marks will be placed on the ground at 0, 2, 12 and 14 meters. Subjects will walk a total of 14 meters. The middle 10 meters (between marks at 2 and 12 meters) will be timed and recorded as their gait speed. | Day 1 of intervention | 
| Gait Speed as Assessed by 10 Meter Walk Test | Subjects will undergo a walking session with Ekso, Ekso will then be removed, and subjects will then perform a 10 Meter Walk Test (10MWT) without use of Ekso exoskeleton. The 10MWT will assess subject's gait speed. Four marks will be placed on the ground at 0, 2, 12 and 14 meters. Subjects will walk a total of 14 meters. The middle 10 meters (between marks at 2 and 12 meters) will be timed and recorded as their gait speed. | Day 2 of intervention | 
| Gait Speed as Assessed by 10 Meter Walk Test | Subjects will undergo a walking session with Ekso, Ekso will then be removed, and subjects will then perform a 10 Meter Walk Test (10MWT) without use of Ekso exoskeleton. The 10MWT will assess subject's gait speed. Four marks will be placed on the ground at 0, 2, 12 and 14 meters. Subjects will walk a total of 14 meters. The middle 10 meters (between marks at 2 and 12 meters) will be timed and recorded as their gait speed. | Day 3 of intervention | 
| Gait Speed as Assessed by 10 Meter Walk Test | Subjects will undergo a walking session with Ekso, Ekso will then be removed, and subjects will then perform a 10 Meter Walk Test (10MWT) without use of Ekso exoskeleton. The 10MWT will assess subject's gait speed. Four marks will be placed on the ground at 0, 2, 12 and 14 meters. Subjects will walk a total of 14 meters. The middle 10 meters (between marks at 2 and 12 meters) will be timed and recorded as their gait speed. | Day 4 of intervention | 
| Gait Speed as Assessed by 10 Meter Walk Test | Subjects will undergo a walking session with Ekso, Ekso will then be removed, and subjects will then perform a 10 Meter Walk Test (10MWT) without use of Ekso exoskeleton. The 10MWT will assess subject's gait speed. Four marks will be placed on the ground at 0, 2, 12 and 14 meters. Subjects will walk a total of 14 meters. The middle 10 meters (between marks at 2 and 12 meters) will be timed and recorded as their gait speed. | Day 5 of intervention |