Acute Mechanisms of Cervical Transcutaneous Electrical Stimulation of the Spinal Cord

Investigating the Acute Effects of Transcutaneous Electrical Stimulation Parameters on Neural Circuits, Motoneuron Behavior and Motor Performance in Individuals With Cervical Spinal Cord Injury

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.

Study Overview

• Status: Withdrawn
• Conditions: Spinal Cord Injuries
• Intervention / Treatment: Device: Cervical Transcutaneous Electrical Spinal Cord Stimulation

• Study Type: Observational

Contacts and Locations

Study Locations

• United States
  • Kentucky
    • Louisville, Kentucky, United States, 40202
      • University of Louisville, Kentucky Spinal Cord Injury Research Centre

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Individuals with chronic, cervical spinal cord injury.

Description

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 exclusion criteria:

• participants with active or inactive implants including cardiac pacemakers, implantable defibrillators, ocular implants, deep brain stimulators, vagus nerve stimulator, and implanted medication pumps
• participants with conductive, ferromagnetic or other magnetic-sensitive metals implanted in their head
• participants with a history of seizures or epilepsy
• participants taking any medication which may reduce seizure threshold

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Individuals with cervical spinal cord injury; Cohort of individuals who have experiences a chronic spinal cord injury at the cervical level (specifically C5-C7).	Device: Cervical 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.; Other Names: tcES

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Motor evoked potentials recruitment curves	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.	Assessment up to 4 hours each visit; up to 4 visits per individual (32 hours)
Intracortical excitability	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.	Assessment up to 4 hours each visit; up to 4 visits per individual (32 hours)
Intramuscular coherence	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.	Assessment up to 4 hours each visit; up to 4 visits per individual (32 hours)
Force control	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.	Assessment up to 4 hours each visit; up to 4 visits per individual (32 hours)

Collaborators and Investigators

• Sponsor: University of Louisville
• Investigators: Principal Investigator: Jessica D'Amico, PhD, University of Louisville

Study record dates

Study Major Dates

• Study Start (Actual): April 6, 2021
• Primary Completion (Actual): February 22, 2022
• Study Completion (Actual): February 22, 2022

Study Registration Dates

• First Submitted: April 6, 2021
• First Submitted That Met QC Criteria: April 12, 2021
• First Posted (Actual): April 13, 2021

Study Record Updates

• Last Update Posted (Actual): October 30, 2023
• Last Update Submitted That Met QC Criteria: October 26, 2023
• Last Verified: October 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Central Nervous System Diseases; Nervous System Diseases; Wounds and Injuries; Trauma, Nervous System; Spinal Cord Diseases; Spinal Cord Injuries
• Other Study ID Numbers: 20.0593

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes