Combining tsDCS and Exoskeleton Gait Training on Spinal Excitability in SCI

Not Applicable

Completed

Conditions: Spinal Cord Injury

Interventions: Device: Ekso
Device: cathode tsDCS
Device: anode tsDCS

Registration Number: NCT02862080

Lead Sponsor: The University of Texas Health Science Center, Houston

Brief Summary: 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: 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.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 4

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

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
no intervention; then no intervention; then anode tsDCS + Ekso; then Ekso; then anode tsDCS + Ekso	Ekso	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.
no intervention; then no intervention; then cathode tsDCS + Ekso; then Ekso; then cathode tsDCS+Ekso	Ekso	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.
no intervention; then no intervention; then Ekso; then cathode tsDCS + Ekso; then Ekso	cathode tsDCS	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.
no intervention; then no intervention; then Ekso; then cathode tsDCS + Ekso; then Ekso	Ekso	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.
no intervention; then no intervention; then Ekso; then anode tsDCS + Ekso; then Ekso	Ekso	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.
no intervention; then no intervention; then cathode tsDCS + Ekso; then Ekso; then cathode tsDCS+Ekso	cathode tsDCS	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.
no intervention; then no intervention; then anode tsDCS + Ekso; then Ekso; then anode tsDCS + Ekso	anode tsDCS	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.
no intervention; then no intervention; then Ekso; then anode tsDCS + Ekso; then Ekso	anode tsDCS	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.

Primary Outcome Measures

Name	Time	Method
Change in Spinal Cord Excitability as Assessed by Percent Change in Soleus H-Reflex From Beginning of Session to End of the Same Session	before and after intervention on day 5	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.
Change in Spinal Cord Excitability as Measured by Percent Change in Soleus H-Reflex From Beginning of Session to End of the Same Session	beginning and end of first no-intervention visit (7 days before any intervention)	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.

Secondary Outcome Measures

Name	Time	Method
Gait Speed as Assessed by 10 Meter Walk Test	Day 5 of intervention	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.