Spinal Cord Injuries
Conditions
Brief summary
The purpose of this study is to examine how delivery of subthreshold electrical stimulation of the spinal cord alters the excitability of neural pathways and consequently movement performance in healthy and spinal cord injured individuals. Specifically, we assess how stimulation parameters such as electrode configurations and stimulation frequency affect spinal excitability, corticospinal excitability, intracortical excitability, motor unit properties and force production. This study is not an intervention study, but a mechanistic study trying to shed light on how this novel neuromodulatory technique acutely affects the central nervous system.
Interventions
DEVICECervical Transcutaneous Electrical Spinal Cord Stimulation
Surface electrodes are placed over the cervical spinal cord. Constant current is delivery through these electrodes. Stimulation frequency and electrode configuration are manipulated, and outcome measures are recorded.
Sponsors
University of Louisville
Study design
Observational model
CASE_CROSSOVER
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
* cervical level injury (C5 to C7) * at least 1 year post-injury
Exclusion criteria
* individuals with damage to the nervous system other than to the spinal cord * pregnant women (effects of stimulation on the fetus are unknown). Transcranial magnetic stimulation-specific
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Motor evoked potentials recruitment curves | Assessment up to 4 hours each visit; up to 4 visits per individual (32 hours) | Motor evoked potentials are obtained to assess changes in the input/output properties of the corticospinal tract during delivery of tcES. Comparisons are made between no stimulation and stimulation at different frequencies, or with different electrode configurations. This assessment is repeated for different muscles on different days. |
| Intracortical excitability | Assessment up to 4 hours each visit; up to 4 visits per individual (32 hours) | Paired stimulation of the motor cortex is used to assess short interval intracortical inhibition intracortical facilitation during delivery of tcES. Comparisons are made between no stimulation and stimulation at different frequencies, or with different electrode configurations. This assessment is repeated for different muscles on different days. |
| Intramuscular coherence | Assessment up to 4 hours each visit; up to 4 visits per individual (32 hours) | High-density surface electromyography is used to decompose motor units and assess changes in intramuscular coherence during performance of a motor task in the presence of tcES. Comparisons are made between no stimulation and stimulation at different frequencies, or with different electrode configurations. This assessment is repeated for different muscles on different days. |
| Force control | Assessment up to 4 hours each visit; up to 4 visits per individual (32 hours) | Force control during a variety of motor tasks is assessed during delivery of tcES. Comparisons are made between no stimulation and stimulation at different frequencies, or with different electrode configurations within each session. This assessment is repeated for different muscles on different days. |
Countries
United States
Outcome results
None listed