Neuropathic Pain and Operant Conditioning of Cutaneous Reflexes After SCI

Targeted Spinal Cord Plasticity for Alleviating SCI-related Neuropathic Pain

The purpose of the second part of the study is to examine the effect of reflex training in the leg to decrease neuropathic pain. For this, the researchers are recruiting 15 individuals with neuropathic pain due to spinal cord injury to participate in the reflex training procedure. The study involves approximately 50 visits with a total study duration of about 6.5 months (3 months for baseline and training phases followed by 1 month and 3 month follow-up visits).

Study Overview

• Status: Recruiting
• Conditions: Pain; Neuropathic Pain; Spinal Cord Injuries; Neurological Injury
• Intervention / Treatment: Behavioral: Operant Conditioning of Cutaneous Reflexes

Detailed Description

As part of the larger study of the relationship between reflexes in the leg and the presence of neuropathic pain, the researchers are also recruiting 30 individuals with spinal cord injury (SCI) total, 15 individuals with neuropathic pain due to SCI and 15 individuals without neuropathic pain. For this portion of the study, there are 2 visits. The first visit will examine cutaneous reflexes in the leg. During the second visit, the study team will assess sensation in the leg and administer questionnaires about pain, functioning, and quality of life. This portion of the study does not involve an intervention.

The study will then recruit 15 individuals who will participate in reflex training, as described in the brief summary.

• Study Type: Interventional
• Enrollment (Estimated): 15
• 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

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. neurologically stable (>1 year post SCI)
2. medical clearance to participate
3. ability to stand with or without an assistive device for at least 3 minutes at a time
4. expectation that current medication will be maintained without change for at least 3 months (stable use of anti-spasticity medication is accepted)
5. For participants with neuropathic pain, the area of neuropathic pain must include lower leg.

Exclusion Criteria:

1. motoneuron injury
2. known cardiac condition
3. medically unstable condition (incl. pregnancy)
4. cognitive impairment
5. uncontrolled peripheral neuropathy
6. frequent use of electrical spinal stimulation (either transcutaneous or epidural) for pain treatment
7. daily use of electrical stimulation to the leg
8. complete lack of cutaneous sensation around foot.

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: Operant Conditioning of Cutaneous Reflexes; Each participant completes 6 baseline sessions and 30 conditioning sessions. In each of the 30 conditioning sessions, while the participant is standing nerves in the lower leg and ankle are stimulated to activate the reflex. The participant attempts to change the reflex activity based on visual feedback. In this way the cutaneous reflex (skin reflex) will be changed to decrease neuropathic pain resulting from spinal cord injury.

Behavioral: Operant Conditioning of Cutaneous Reflexes; This is a training intervention in which people with a spinal cord injury are trained to change (increase or decrease) the activity of a certain spinal reflex. By changing this reflex, it is hypothesized that individuals can reduce pain due to spinal cord injury.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in minimum stimulation intensity required to barely detect the sensation (perceived threshold, perT)	This is measured by slowly increasing the nerve stimulation and recording the minimum intensity of stimulation at which the participant is barely able to perceive the sensation. A decrease in this threshold would demonstrate improved sensation.	change from baseline to immediately after completing the training protocol, at 1 month follow up and at 3 months follow up
Change in minimum intensity at which the sensation covers the maximum area of skin (radiating threshold, RT)	This is measured by slowly increasing the nerve stimulation and recording the minimum intensity of stimulation at which the sensation covers the maximum skin area). A decrease in this threshold indicates improved sensation.	change from baseline to immediately after completing the training protocol, at 1 month follow up and at 3 months follow up
Change in minimum intensity at which the stimulus become painful (pain threshold, PainT)	This is measured by slowly increasing the nerve stimulation and recording the intensity of stimulation at which the stimulation first becomes painful. An increase in this threshold indicates an increased tolerance to pain.	change from baseline to immediately after completing the training protocol, at 1 month follow up and at 3 months follow up
Change in pain as measured by the McGill Pain Questionnaire (MPQ)	The MPQ is a self-report questionnaire that assesses quality and intensity of pain. Scores range from 0 (no pain) to 78 (severe pain).	Completed at baseline, start of conditioning visits 13, 19, and 25, after completing 30 conditioning sessions, 1 month follow up, and 3 months follow up
Change in neuropathic pain as measured by the Neuropathic Pain Symptom Inventory (NPSI)	The NPSI is a self-report questionnaire that characterizes neuropathic pain symptom severity. Participants rate different symptoms of neuropathic pain on a scale of 0 (no pain) to 10 (intense pain).	Completed at baseline, start of conditioning visits 13, 19, and 25, after completing 30 conditioning sessions, 1 month follow up, and 3 months follow up

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in ability to perceive various types of sensations as indicated by Quantitative Sensory Testing (QST)	The QST is a battery of assessments that measure sensory thresholds for pain, touch, vibration, and hot and cold temperature sensations.	Completed at baseline, start of conditioning visits 13, 19, and 25, after completing 30 conditioning sessions, 1 month follow up, and 3 months follow up
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, with higher scores indicated increase independence.	Completed at baseline, after completing 30 conditioning sessions, 1 month follow up, and 3 months follow up
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).	Completed at baseline, after completing 30 conditioning sessions, 1 month follow up, and 3 months follow up
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	Completed at baseline, after completing 30 conditioning sessions, 1 month follow up, and 3 months follow up

Collaborators and Investigators

• Sponsor: Medical University of South Carolina
• Collaborators: United States Department of Defense
• Investigators: Principal Investigator: Aiko Thompson, PhD, Medical University of South Carolina

Study record dates

Study Major Dates

• Study Start (Actual): March 27, 2023
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): October 1, 2026

Study Registration Dates

• First Submitted: August 5, 2022
• First Submitted That Met QC Criteria: August 5, 2022
• First Posted (Actual): August 8, 2022

Study Record Updates

• Last Update Posted (Estimated): October 10, 2025
• Last Update Submitted That Met QC Criteria: October 8, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Keywords: Neuroplasticity
• Additional Relevant MeSH Terms: Neurologic Manifestations; Central Nervous System Diseases; Nervous System Diseases; Wounds and Injuries; Neuromuscular Diseases; Peripheral Nervous System Diseases; Spinal Cord Diseases; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain; Neuralgia; Spinal Cord Injuries; Trauma, Nervous System
• Other Study ID Numbers: 118771; CDMRP-SC210118 (Other Grant/Funding Number: Department of Defense)

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