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

Operant Conditioning of Spinal Reflexes to Enhance Motor Function Recovery After Spinal Cord Injury

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.

Study Overview

• Status: Recruiting
• Conditions: Paralysis; Spinal Cord Injuries; Spasticity, Muscle; Neurological Injury
• Intervention / Treatment: Behavioral: Spinal Reflex Operant Down Conditioning

• Study Type: Interventional
• Enrollment (Estimated): 25
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Blair Dellenbach, MSOT; Phone Number: 843-792-6313; Email: stecb@musc.edu

Study Locations

• United States
  • South Carolina
    • Charleston, South Carolina, United States, 29425
      • Recruiting
      • Medical University of South Carolina
      • Contact: Blair Dellenbach, MSOT; Phone Number: 843-792-6313; Email: stecb@musc.edu
    • Charleston, South Carolina, United States, 29425
      • Not yet recruiting
      • Medical University of South Carolina
      • Contact: Blair Dellenbach, MSOT; Phone Number: 843-792-6313; Email: stecb@musc.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Validation of the new training system; 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; 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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 Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in the level of assistance required to walk 10 meters as measured by the Walking Index for Spinal Cord Injury (WI-SCI)	WI-SCI classifies the level of assistance needed to perform the 10MWT; the scale is from 0-20 with 20 being no assistance required at all. An increase of score indicates increased level of independence while walking.	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)	A decrease in the score on the MAS indicates a decrease in spasticity. To measure spasticity, resistance to passive movement about a joint is tested at a range of velocities. The score ranges from 0-4 (i.e., 0: normal muscle tone; 4: rigid in flexion or extension).	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	An increase in score on the Berg Balance scale indicates better balance and decreased fall risk. For each item, the score ranges from 0-4 with a maximum total score of 56.	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)	An increase in the the score on the SCIM III indicates increased basic functional independence. This is a self report questionnaire with 19 items in three sub-scales: (1) self-care (6 items, subscore 0-20); (2) respiration and sphincter management (4 items, subscore 0-40); and (3) mobility (9 items, subscore 0-40). The total score ranges from 0-100.	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)	An increase in the score on the FIM indicates and increase in functional independence. This 18-item, clinician-reported scale assesses function in 6 areas including self-care, continence, mobility, transfers, communication, and cognition. Each of the 18 items is graded on a scale of 1-7 based on level of independence in that item (1 = total assistance required, 7 = complete independence).	Before Baseline, after completion of intervention sessions (approximately 10 weeks), 1 month and 3 months after the completion of intervention
Change in quality of life as measured by Spinal Cord Injury Quality of Life and Participation Questionnaire (SCI-QOL)	An increase in score on the SCI-QOL indicates an increase in quality of life.	Before Baseline, after completion of intervention sessions (approximately 10 weeks), 1 month and 3 months after the completion of intervention
Change is strength of key muscles in the lower extremity as measured by Manual Muscle Testing (MMT)	To test the strength against the examiner's resistance and grading the patient's strength on a 0 to 5 scale. 0: No muscle activation; 1: Trace muscle activation, such as a twitch, without achieving full range of motion; 2: Muscle activation with gravity eliminated, achieving full range of motion; 3: Muscle activation against gravity, full range of motion; 4: Muscle activation against some resistance, full range of motion; 5: Muscle activation against examiner's full resistance, full range of motion.	Before Baseline, after completion of intervention sessions (approximately 10 weeks), 1 month and 3 months after the completion of intervention
Change in dynamic and static muscle length and joint range of motion (ROM) as measured by Tardieu Scale	An increase in joint range of motion (deg) indicates ROM more similar to individuals without injury	Before Baseline, after completion of intervention sessions (approximately 10 weeks), 1 month and 3 months after the completion of intervention

Collaborators and Investigators

• Sponsor: Medical University of South Carolina
• Collaborators: National Institute of Neurological Disorders and Stroke (NINDS)
• Investigators: Principal Investigator: Aiko Thompson, PhD, Medical University of South Carolina

Study record dates

Study Major Dates

• Study Start (Actual): August 23, 2023
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: October 14, 2021
• First Submitted That Met QC Criteria: October 14, 2021
• First Posted (Actual): October 26, 2021

Study Record Updates

• Last Update Posted (Estimated): September 9, 2025
• Last Update Submitted That Met QC Criteria: September 5, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: Neuroplasticity; Spinal Reflex
• Additional Relevant MeSH Terms: Neurologic Manifestations; Musculoskeletal Diseases; Central Nervous System Diseases; Nervous System Diseases; Muscular Diseases; Muscle Hypertonia; Neuromuscular Manifestations; Wounds and Injuries; Spinal Cord Diseases; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Muscle Spasticity; Spinal Cord Injuries; Paralysis; Trauma, Nervous System
• Other Study ID Numbers: 00095583; 4U44NS114420-03 (U.S. NIH Grant/Contract)

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: No
• product manufactured in and exported from the U.S.: No