Reflex Training for Spinal Cord Injury

Overseen By Blair Dellenbach, MSOT

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Medical University of South Carolina

Must be taking: Antispasticity medications

Must not be taking: Antidepressants

Disqualifiers: Motoneuron injury, Cardiac condition, Neurological condition, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 39

25 Participants Needed

Trial Summary

What is the purpose of this trial?

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.

Will I have to stop taking my current medications?

The trial does not require you to stop taking your current medications. However, your medications, including any for spasticity, should remain stable during the study. Changes in medication are unlikely but will be monitored and recorded.

What data supports the effectiveness of the treatment Spinal Reflex Operant Down Conditioning for spinal cord injury?

Research shows that operant conditioning of spinal reflexes can improve walking and balance in people with incomplete spinal cord injuries by targeting specific reflex pathways, leading to widespread beneficial changes in the nervous system. People have reported walking faster and farther, with less spasticity and better balance after undergoing this treatment. ^{1 2 3 4 5}

Is reflex training for spinal cord injury safe for humans?

Studies in humans and animals suggest that operant conditioning of spinal reflexes is generally safe, with no significant safety concerns reported. This method has been used to improve motor function in people with spinal cord injuries, indicating its potential as a safe rehabilitation therapy. ^{1 2 3 6 7}

How is the Reflex Training for Spinal Cord Injury treatment different from other treatments?

This treatment is unique because it uses operant conditioning to gradually change spinal reflexes, which can improve movement and walking in people with spinal cord injuries by promoting beneficial changes in the nervous system. ^{1 2 5 8 9}

Research Team

Aiko Thompson, PhD

Principal Investigator

Medical University of South Carolina

Eligibility Criteria

This trial is for individuals with chronic incomplete spinal cord injury who can walk at least 10 meters, have leg spasticity, and are medically stable. They must be able to consent and not expect medication changes during the study. Excluded are those with unstable health, cognitive impairments, other neurological conditions, daily use of certain electrical stimulation devices, motoneuron injuries, serious heart issues, inability to test lower limb mobility or weight bearing, recent deep vein thrombosis or pregnancy.

Inclusion Criteria

My spinal cord injury above T11 has been stable for over a year.

Medical clearance to participate

My current medications are expected to stay the same during the trial's start period.

Exclusion Criteria

I have a history of heart issues, like a heart attack or use a pacemaker.

I have had a deep vein thrombosis in the last 6 months.

I cannot perform tests that require walking or standing.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Baseline

Participants complete 6 baseline sessions to measure initial reflex activity

2 weeks

6 visits (in-person)

Conditioning

Participants undergo 30 conditioning sessions to down-condition the soleus H-reflex

10 weeks

30 visits (in-person)

Follow-up

Participants are monitored for changes in spasticity, muscle strength, and functional independence

3 months

3 visits (in-person)

Treatment Details

Interventions

• Spinal Reflex Operant Down Conditioning

Trial Overview The trial tests a reflex training system designed to reduce the size of targeted muscle reflexes in people with spinal cord injuries. Participants will undergo about 45 sessions over six months to see if this method can help manage spasticity in their legs by conditioning their spinal reflexes.

Participant Groups

Group I: Validation of the new training system Experimental Treatment 1 Intervention

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.

Who Is Running the Clinical Trial?

Medical University of South Carolina

Lead Sponsor

Trials

994

Recruited

7,408,000+

National Institute of Neurological Disorders and Stroke (NINDS)

Collaborator

Trials

1,403

Recruited

655,000+

Findings from Research

Operant-conditioning protocols that reward specific electromyographic responses can effectively modify spinal reflex pathways, leading to changes in reflex activity and associated behaviors in both animals and humans.

In individuals with partial spinal cord injuries, these conditioning techniques can enhance locomotion and promote widespread beneficial plasticity in the nervous system, suggesting a promising therapeutic approach for rehabilitation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Targeted neuroplasticity for rehabilitation. Thompson, AK., Wolpaw, JR.[2018]

Operant conditioning of spinal reflexes has evolved over 35 years from basic science to a promising rehabilitation therapy for spinal cord injuries, showing significant potential for enhancing nervous system plasticity.

Initial studies in both animal models and humans indicate that reflex conditioning can lead to exciting therapeutic outcomes, highlighting the importance of basic research in informing clinical applications.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Operant conditioning of spinal reflexes: from basic science to clinical therapy. Thompson, AK., Wolpaw, JR.[2022]

Operant conditioning of spinal reflexes can significantly improve motor function in individuals with incomplete spinal cord injury (SCI), as shown by down-conditioning the soleus H-reflex, which led to increased walking speed and symmetry in patients.

The study indicates that targeting specific reflex pathways not only enhances the targeted reflex but also promotes widespread recovery, resulting in noticeable improvements in daily activities such as walking, balance, and reduced spasticity.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Restoring walking after spinal cord injury: operant conditioning of spinal reflexes can help. Thompson, AK., Wolpaw, JR.[2022]

A new conditioning protocol targeting the swing-phase of locomotion in individuals with incomplete spinal cord injury (SCI) significantly reduced the size of the H-reflex more quickly and effectively than traditional steady-state methods, with effects lasting at least 6 months.

This swing-phase conditioning not only decreased the reflex but also improved walking speed and muscle activity, suggesting a promising approach for enhancing recovery in SCI and potentially other movement disorders.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

H-reflex conditioning during locomotion in people with spinal cord injury. Thompson, AK., Wolpaw, JR.[2022]

Operant conditioning protocols can effectively modify spinal reflexes, which are fundamental behaviors, providing valuable insights into the mechanisms of learning.

These protocols can also promote neural plasticity, potentially aiding in the recovery of motor skills like walking in individuals with spinal cord injuries or related disorders.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The simplest motor skill: mechanisms and applications of reflex operant conditioning. Thompson, AK., Wolpaw, JR.[2021]

The corticospinal tract (CST) is crucial for both the acquisition and maintenance of a conditioned decrease in the H-reflex, a model for studying spinal cord reflexes, as shown in a rat study involving various spinal cord transections.

Other major spinal pathways, such as the dorsal column and lateral column, do not play a significant role in this process, suggesting that targeting the CST could lead to new strategies for enhancing recovery of motor functions after spinal cord injuries.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Probable corticospinal tract control of spinal cord plasticity in the rat. Chen, XY., Wolpaw, JR.[2017]

Spinal stretch reflexes (SSRs) can be conditioned to be either smaller or larger, as shown in studies with monkey models and able-bodied humans, indicating a potential for rehabilitation strategies.

Conditioning techniques have been successful in reducing hyperactive SSRs in spinal-cord-injured patients with some residual control, suggesting that these methods could improve movement control in this population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Plasticity in the Central Nervous System: Operant Conditioning of the Spinal Stretch Reflex. Segal, RL.[2016]

In a study involving 12 participants with chronic spastic hemiparesis after stroke, operant down-conditioning successfully reduced the soleus H-reflex size by an average of 30% in half of the participants, indicating potential for reflex modification even in cases of supraspinal injury.

Participants whose H-reflex decreased also showed improvements in walking speed, with an average increase of 0.14 m/s, suggesting that reflex down-conditioning can enhance motor function in stroke patients, although the overall success rate was lower than in individuals with incomplete spinal cord injury.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Operant down-conditioning of the soleus H-reflex in people after stroke. Thompson, AK., Gill, CR., Feng, W., et al.[2023]

In a study involving individuals with chronic incomplete spinal cord injury, down-conditioning the soleus H-reflex through 30 sessions led to significant improvements in locomotion, with two-thirds of participants experiencing a decrease in H-reflex size and reporting faster, more symmetrical walking.

The results indicate that reflex-conditioning protocols can effectively enhance recovery of motor function by targeting specific spinal pathways, suggesting potential for personalized rehabilitation strategies in spinal cord injuries and other movement disorders.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Operant conditioning of a spinal reflex can improve locomotion after spinal cord injury in humans. Thompson, AK., Pomerantz, FR., Wolpaw, JR.[2022]

References

1. Netherlands pubmed.ncbi.nlm.nih.gov

Targeted neuroplasticity for rehabilitation. [2018]

2. Switzerland pubmed.ncbi.nlm.nih.gov

Operant conditioning of spinal reflexes: from basic science to clinical therapy. [2022]

3. United States pubmed.ncbi.nlm.nih.gov

Restoring walking after spinal cord injury: operant conditioning of spinal reflexes can help. [2022]

4. England pubmed.ncbi.nlm.nih.gov

H-reflex conditioning during locomotion in people with spinal cord injury. [2022]

5. United States pubmed.ncbi.nlm.nih.gov

The simplest motor skill: mechanisms and applications of reflex operant conditioning. [2021]

6. United States pubmed.ncbi.nlm.nih.gov

Probable corticospinal tract control of spinal cord plasticity in the rat. [2017]

7. England pubmed.ncbi.nlm.nih.gov

Plasticity in the Central Nervous System: Operant Conditioning of the Spinal Stretch Reflex. [2016]

8. Switzerland pubmed.ncbi.nlm.nih.gov

Operant down-conditioning of the soleus H-reflex in people after stroke. [2023]

9. United States pubmed.ncbi.nlm.nih.gov

Operant conditioning of a spinal reflex can improve locomotion after spinal cord injury in humans. [2022]