Operant Conditioning of Spinal Reflexes Training System--Reflex Operant Down Conditioning

Medical University of South Carolina (MUSC)

Status: Enrolling

Conditions: Spasticity, Muscle; Spinal Cord Injuries; Neurological Injury; Paralysis

Treatments: Behavioral: Spinal Reflex Operant Down Conditioning

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT05094362

00095583

4U44NS114420-03 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

The purpose of this study is to validate the capacity of a reflex training system to change the size of the targeted reflex. For this, the researchers are recruiting 25 individuals with chronic incomplete SCI who have spasticity in the leg to participate in the reflex training procedure. The study involves approximately 45 visits with a total study duration of about 6 months.

Enrollment: 25 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. a clinically stable spinal cord injury (above T11) that occurred at least one year previously
2. the ability to ambulate at least 10 m with or without an assistive device (i.e., walker, crutches, or cane, not parallel bars) within 100 sec (those with 10-meter walking time >100 sec are excluded because it is unlikely that they are able to participate in and complete our planned locomotion evaluation procedures)
3. clinical signs of spasticity in the plantarflexor muscles at least unilaterally (i.e., hyperreactivity to Achilles tendon tap, and increased muscle tone, score >1 on Modified Ashworth scale)
4. spastic hyperreflexia reflected in exaggerated H-reflex
5. functionally and medically stable for at least 3 months
6. medical clearance to participate
7. reasonable expectation that current medications (including antispasticity medication such as baclofen, diazepam, and tizanidine) will not change over the conditioning period. Each participant's medication and dosage will be monitored and recorded throughout the study. Once enrolled, the subject will remain enrolled even if medication changes. (Because only neurologically stable subjects will enter this study, medication changes will be unlikely.)

Exclusion criteria

1. motoneuron injury;
2. a cardiac condition (history of myocardial infarct, pacemaker use, etc.)
3. an unstable medical condition
4. a pre-existing or confounding neurological condition (e.g., history of Multiple Sclerosis (MS), Traumatic Brain Injury (TBI), Stroke, Parkinson's disease)
5. a condition that prevents lower extremity mobility testing or weight bearing (e.g. fracture, severe sprain/strain, botox muscular injection) (orthotic knee hyperextension is not excluded; in severe cases of knee hyperextension, the brace can be worn during the study sessions)
6. a cognitive impairment that precludes giving informed consent (e.g., severe intellectual disability)
7. use of a functional electrical stimulation (FES) foot-drop stimulator or an FES bicycle on a daily basis (FES applied to the arm is acceptable)
8. deep vein thrombosis within the past 6 months
9. depression (due to potential interference of anti-depressant medication with the intervention and possible reduced participation reliability)
10. pregnancy (due to expected changes in weight and posture and potentially unstable medical condition).

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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25 participants in 1 patient group

Validation of the new training system

Experimental group

Description:

The researchers will measure changes in H-reflex size achieved with the use of the new system and compare these measures with the existing results in 25 spastic individuals with chronic incomplete SCI. Each participant completes 6 baseline sessions and 30 conditioning sessions. In the 30 conditioning sessions, the soleus H-reflex will be down-conditioned to decrease the activity of the hyperactive spinal stretch reflex pathway in people with spasticity that is characterized by exaggerated reflex activity. It is anticipated that the magnitude of reflex change obtained with the use of the new system would be greater or at least the same as the bench-marked values from the previous studies that used the old prototype reflex conditioning system.

Treatment:

Behavioral: Spinal Reflex Operant Down Conditioning