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

NCT05094362 | Recruiting

• 2 other identifiers: 000955834U44NS114420-03
• Study Type: interventional
• Target: 25
• Locations: 1 country
• Sites: 2

Brief Summary

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.

Conditions

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

Keywords

Neuroplasticity; Spinal Reflex

Outcome Measures

Primary Outcomes (3)

• Change in reflex activity as measured by the H-reflex amplitude (mV) in response to nerve stimulation

  Decreased H-reflex amplitude indicates reduced reflex activity and a more normal reflex response to muscle activity

  Before Baseline, after completion of intervention sessions (approximately 10 weeks), 1 month and 3 months after the completion of intervention

• Change in walking speed (m/s) as measured by the 10-meter Walk Test (10MWT)

  Speed of the participant's fastest comfortable walking speed across 10 meters. Decreased time (sec) demonstrates increased walking speed (m/s)

  Before Baseline, after completion of intervention sessions (approximately 10 weeks), 1 month and 3 months after the completion of intervention

• Change in walking distance (meters) as measured by the 6-minute walk test

  The distance walked in 6 minutes in measured. The participant is asked to walk at his/her fastest comfortable speed on an indoor walkway.

  Before Baseline, after completion of intervention sessions (approximately 10 weeks), 1 month and 3 months after the completion of intervention

Secondary Outcomes (8)

• Change in the level of assistance required to walk 10 meters as measured by the Walking Index for Spinal Cord Injury (WI-SCI)

  Before Baseline, after completion of intervention sessions (approximately 10 weeks), 1 month and 3 months after the completion of intervention

• Change in level of spasticity in the more affected leg as measured by the Modified Ashworth Scale (MAS)

  Before Baseline, after completion of intervention sessions (approximately 10 weeks), 1 month and 3 months after the completion of intervention

• Change in balance as measured by Berg Balance Scale

  Before Baseline, after completion of intervention sessions (approximately 10 weeks), 1 month and 3 months after the completion of intervention

• Change in basic functional independence as measured by the Spinal Cord Independence Measure (SCIM III)

  Before Baseline, after completion of intervention sessions (approximately 10 weeks), 1 month and 3 months after the completion of intervention

• Change in functional independence as measured by the Functional Independence Measure (FIM)

  Before Baseline, after completion of intervention sessions (approximately 10 weeks), 1 month and 3 months after the completion of intervention

Study Arms (1)

Validation of the new training system

EXPERIMENTAL

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.

Behavioral: Spinal Reflex Operant Down Conditioning

Interventions

Spinal Reflex Operant Down Conditioning BEHAVIORAL

This is a training intervention in which people with a spinal cord injury are trained to reduce the activity of a certain spinal reflex. By decreasing this reflex, individuals decrease hyperactivity in the reflex and can reduce spasticity.

Validation of the new training system

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• a clinically stable spinal cord injury (above T11) that occurred at least one year previously
• 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)
• 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)
• spastic hyperreflexia reflected in exaggerated H-reflex
• functionally and medically stable for at least 3 months
• medical clearance to participate
• 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.)

You may not qualify if:

• motoneuron injury;
• a cardiac condition (history of myocardial infarct, pacemaker use, etc.)
• an unstable medical condition
• a pre-existing or confounding neurological condition (e.g., history of Multiple Sclerosis (MS), Traumatic Brain Injury (TBI), Stroke, Parkinson's disease)
• 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)
• a cognitive impairment that precludes giving informed consent (e.g., severe intellectual disability)
• 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)
• deep vein thrombosis within the past 6 months
• depression (due to potential interference of anti-depressant medication with the intervention and possible reduced participation reliability)
• pregnancy (due to expected changes in weight and posture and potentially unstable medical condition).

Sponsors & Collaborators

• Medical University of South Carolina: lead
• National Institute of Neurological Disorders and Stroke (NINDS): collaborator

Study Sites (2)

Medical University of South Carolina

Charleston, South Carolina, 29425, United States

NOT YET RECRUITING

Medical University of South Carolina

Charleston, South Carolina, 29425, United States

RECRUITING

MeSH Terms

Conditions

Spinal Cord Injuries; Trauma, Nervous System; Paralysis; Muscle Spasticity

Condition Hierarchy (Ancestors)

Spinal Cord Diseases; Central Nervous System Diseases; Nervous System Diseases; Wounds and Injuries; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Muscular Diseases; Musculoskeletal Diseases; Muscle Hypertonia; Neuromuscular Manifestations

Study Officials

• Aiko Thompson, PhD

  Medical University of South Carolina

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Blair Dellenbach, MSOT

CONTACT

843-792-6313; stecb@musc.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: October 14, 2021
• First Posted: October 26, 2021
• Study Start: August 23, 2023
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: September 9, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

US (2)