Motoneuron Recruitment and Motor Evoked Potential Up-Conditioning (MEP) in Spinal Cord Injury (SCI)

Medical University of South Carolina (MUSC)

Status

Enrolling

Conditions

Spinal Cord Injuries and Disorders (SCI/D)

Spinal Cord Injury

Treatments

Behavioral: Motor Evoked Potential (MEP) Operant Conditioning

Study type

Interventional

Funder types

Other

NIH

Identifiers

NCT07179822

1R21HD118383 (U.S. NIH Grant/Contract)

Pro00145581

Details and patient eligibility

About

The purpose of this research study is to examine the effect of a brain stimulation training to improve the function of brain-spinal cord- muscle connections. Because brain-to-muscle pathways are very important in our movement control, restoring function of these pathways may improve movement problems after injuries. Spinal cord injury causes damage to the brain-to-muscle connection. However, when the injury is "incomplete", there is a possibility that some of the brain-to-muscle pathways are still connected and may be trained to improve movement function. For examining brain-to-muscle pathways, investigators use a transcranial magnetic stimulator. Investigators hope that the results of this research study will help us develop new treatments for people who have movement disabilities. This study will require about 42 visits over the first 14 weeks, and another 6 visits over an additional 3 months. Each visit will take about 1 ½ hours.

Full description

Regaining arm/hand function is one of the top priorities of individuals with tetraplegia and is a challenging problem, partly due to the complex nature of upper limb motor function. Through mass practice and conventional therapy, functions can be restored partially, likely through compensation rather than induction of relevant corticospinal plasticity. In such cases, corticospinal recruitment of motoneurons and resulting muscle activation could remain impaired and continue to limit function recovery. In people with incomplete SCI, voluntary activation of the muscles below the injury level is often diminished, due at least partly to impaired motor unit behaviors. Abnormal motoneuron recruitment and motor unit firing, also found in other CNS disorders, would certainly hinder effective production of motor functions. Thus, to enhance upper limb motor rehabilitation beyond what conventional therapy has been able to achieve, a method to improve corticospinal recruitment of a targeted pool of motoneurons would be needed. Here, investigators hypothesize that wrist extensor MEP up-conditioning can improve forearm motor functions in people with cervical SCI by increasing the corticospinal excitability and improving corticospinal recruitment of wrist extensor motoneurons.

Enrollment

15 estimated patients

Sex

All

Ages

18+ years old

Volunteers

No Healthy Volunteers

Inclusion criteria

Adult (≥18 yrs old)
a history of injury to spinal cord at or above C6
neurologically stable (>1 year post SCI)
medical clearance to participate
weak wrist extension at least unilaterally
expectation that current medication will be maintained without change for at least 3 months.
- Stable use of anti-spasticity medication (e.g., baclofen, diazepam, tizanidine) is accepted. (Because only neurologically stable subjects will enter this study, medication changes will be unlikely.)
- In participants with bilateral wrist extension weakness in whom Extensor Carpi Radialis (ECR) MEP can be elicited in both arms, the more severely impaired arm is studied. In participants with unilateral wrist weakness or in participants with bilateral wrist weakness in whom an ECR MEP can be elicited in only one arm, that arm is studied.

Exclusion criteria

motoneuron injury
unstable medical condition
cognitive impairment (because the studied intervention is a learning-based intervention)
a history of epileptic seizures
a pre-existing or confounding neurological condition (e.g., history of MS, Stroke, Parkinson's disease)
metal implants in the cranium
implanted biomedical device in or above the chest (e.g., a cardiac pacemaker, cochlear implant)
no measurable MEP elicited in the ECR
inability to produce any voluntary ECR EMG activity
extensive use of functional electrical stimulation to the arm on a daily basis (as it may interfere with or augment the effects of MEP conditioning itself)
pregnancy (due to changes in posture and potential medical instability)
inability or unwillingness of subject or legal guardian/representative to give informed consent