Spinal Plasticity to Enhance Motor Retraining After Stroke

Study Overview
=================
Brief Summary
-----------------
The objective of this project is to study the effects of an emerging noninvasive neuromodulation strategy in human stroke survivors with movement-related disability. Muscle weakness after stroke results from the abnormal interaction between cells in the brain that send commands to control movement and cells in the spinal cord that cause muscles to produce movement. The neuromodulation strategy central to this project has been shown the strengthen the physical connection between both cells, producing a change in movement potential of muscles weakened by stroke.

Detailed Description
-----------------
Stroke is a leading cause of serious long-term disability in the United States with 795,000 individuals suffering a new or recurrent stroke each year. In most cases, disability is associated with incomplete motor recovery of the paretic limb. Full recovery is often not achieved, creating a need for neuromodulation strategies that target the physiological mechanisms impaired by stroke to fully harness the adaptive capacity of the nervous system. The neuromodulation protocol that will be tested in these experiments will target connections between the brain and spinal cord with noninvasive stimulation to enhance movement potential of the hand. Individuals who experienced a single stroke at least 6 months ago may be eligible to participate.

Official Title
-----------------
Plasticity in the Spinal Cord to Enhance Motor Retraining After Stroke

Conditions
-----------------
Stroke, Cerebrovascular Accident, Hemiparesis

Intervention / Treatment
-----------------
* Procedure: Noninvasive neuromodulation via paired corticospinal-motoneuronal stimulation (PCMS)


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Between the ages of 18 and 75 years old Diagnosis of first-ever stroke Stroke onset of at least six months prior to the time of participation Exclusion Criteria: History of seizure or epilepsy Ferromagnetic metallic implants, pacemakers, other implanted devices, or ventilators (for subjects undergoing MRI) Pregnant or expecting to become pregnant Difficulty maintaining alertness and/or remaining still Body weight > 300 lbs due to MRI scanner dimensions (for subjects undergoing MRI) Cognitive or language impairments that would interfere with the ability to follow simple instructions, as judged by the investigators Diagnosis of movement disorder(s) other than stroke

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Transcranial magnetic stimulation targeting the region of the brain responsible for voluntary movement control and electrical stimulation to a peripheral nerve innervating hand muscles will be triggered at an interval that elicits action potentials arriving in a set sequence and predetermined delay in the spinal cord.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Physiology<br>Different neural elements will be stimulated and evoked potentials will be recorded via electromyography. Metrics used to quantify evoked potentials will be used to infer changes in physiological functioning of the nervous system. | Procedure: Noninvasive neuromodulation via paired corticospinal-motoneuronal stimulation (PCMS)<br>* This study is a novel approach to studying neuroplasticity after stroke. Previous work in humans with incomplete spinal cord injury demonstrates that the resulting plasticity transiently enhances motor output, indicating that there is also therapeutic potential. This study will attempt to induce bi-directional plasticity in corticospinal-motoneuronal synapses serving an intrinsic hand muscle of the hemiparetic limb. Control experiments will be completed to provide evidence of the neurophysiological mechanism(s) mediating the effect and to examine behavioral effects.<br>|
| Experimental: Behavior<br>A visuomotor task will be performed and force signals will be recorded. Metrics used to quantify force signals will be used to infer changes in control processes governing movement. | Procedure: Noninvasive neuromodulation via paired corticospinal-motoneuronal stimulation (PCMS)<br>* This study is a novel approach to studying neuroplasticity after stroke. Previous work in humans with incomplete spinal cord injury demonstrates that the resulting plasticity transiently enhances motor output, indicating that there is also therapeutic potential. This study will attempt to induce bi-directional plasticity in corticospinal-motoneuronal synapses serving an intrinsic hand muscle of the hemiparetic limb. Control experiments will be completed to provide evidence of the neurophysiological mechanism(s) mediating the effect and to examine behavioral effects.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Physiology | Different neural elements will be stimulated and evoked potentials will be recorded via electromyography. Metrics used to quantify evoked potentials will be used to infer changes in physiological functioning of the nervous system. | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Behavior | A visuomotor task will be performed and force signals will be recorded. Metrics used to quantify force signals will be used to infer changes in control processes governing movement. | 12 months | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Neuromodulation, Transcranial magnetic stimulation (TMS), Electrical stimulation