Reflex Conditioning for Cerebral Palsy

(SRC-CP Trial)

Overseen by Kathleen Friel, PhD

Age: 18+

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Academic

Recruiting

Sponsor: Burke Medical Research Institute

Must not be taking: Antiseizure medicines

Disqualifiers: Pregnancy, Uncontrolled diabetes, Cardiac conditions, others

No Placebo Group

Trial Summary

What is the purpose of this trial?

This trial involves training reflexes to reduce muscle tightness in adults with spastic Cerebral Palsy. The treatment uses exercises to help the body learn to control muscle tightness better. If successful, it could offer a new, non-invasive way to improve movement and daily activities for these patients.

Will I have to stop taking my current medications?

No, you will not have to stop taking your current medications. The trial requires that your current medication remains unchanged for 3 months.

What data supports the effectiveness of the treatment Soleus Stretch Reflex Operant Conditioning for cerebral palsy?

Research shows that operant conditioning of the soleus stretch reflex can change reflex size, which is related to motor function, and may improve movement rehabilitation in people with central nervous system disorders. Additionally, a study found that feedback training to reduce the stretch reflex gain significantly decreased spasticity in individuals with cerebral palsy. ^{1 2 3 4 5}

Is reflex conditioning for cerebral palsy safe for humans?

Research shows that reflex conditioning, like the soleus H-reflex operant conditioning, does not cause long-term changes in muscle reflexes or disturb normal movement in healthy people. Additionally, studies on people with cerebral palsy indicate that reflex training can reduce muscle stiffness without harmful effects. ^{1 2 4 5 6}

How is the Soleus Stretch Reflex Operant Conditioning treatment different from other treatments for cerebral palsy?

This treatment is unique because it uses operant conditioning to change the size of the soleus stretch reflex, which can improve motor function by enhancing the brain and spinal cord's ability to adapt and learn new motor skills. Unlike other treatments, it focuses on modifying reflex pathways directly related to movement, potentially offering a novel approach to rehabilitation for cerebral palsy. ^{1 2 3 4 7}

Research Team

Kathleen Friel, PhD

Principal Investigator

Burke Neurological Institute

Eligibility Criteria

Adults over 18 with spastic Cerebral Palsy, able to walk at least 10 meters with or without help. They should be classified as level I-III in motor function and not planning any medication changes for three months. Participants must not be pregnant, have uncontrolled diabetes, skin disorders, heart conditions, latex allergies, recent Botox treatments or surgeries on the affected leg.

Inclusion Criteria

I am 18 years old or older.

I have been diagnosed with spastic Cerebral Palsy.

I can walk or move with some assistance.

Exclusion Criteria

I have not had a seizure since I was 2 years old.

I have a history of heart conditions.

I have weak muscle movement in my ankle and foot.

Trial Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Baseline

Participants complete 6 baseline sessions to establish initial reflex measurements

2 weeks

6 visits (in-person)

Treatment

Participants undergo 24 down conditioning sessions to decrease the magnitude of the H-Reflex

8 weeks

24 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

3 months

3 visits (in-person)

Treatment Details

Interventions

• Soleus Stretch Reflex Operant Conditioning (Behavioral Intervention)

Trial Overview The trial is testing a technique called spinal reflex conditioning on adults with Cerebral Palsy to reduce the H-Reflex magnitude in their muscles. It involves baseline assessments followed by sessions thrice weekly where participants work to decrease this reflex through specific trials.

Participant Groups

Group I: Spinal reflex conditioning Experimental Treatment 1 Intervention

The OC intervention includes 6 baseline sessions and 24 conditioning/ no conditioning sessions held 3 times/week. To elicit an H-reflex, participants will be asked to stand in a comfortable position. Small pulses of energy will be applied to a nerve in the leg called the tibial nerve. We will record when the participant maintains leg muscle activity. During the intervention, participants will be trained to decrease their reflex in their calf.

Who Is Running the Clinical Trial?

Burke Medical Research Institute

Lead Sponsor

Trials

24

Recruited

1,500+

Findings from Research

Operant conditioning can effectively change the size of the soleus stretch reflex (M1), with participants able to significantly increase or decrease M1 size, indicating potential for rehabilitation in individuals with CNS disorders.

The study found that changes in the stretch reflex involved both immediate task-dependent adaptations and longer-term changes, suggesting that this method could be a valuable tool for enhancing motor function and rehabilitation strategies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Acquisition of a simple motor skill: task-dependent adaptation and long-term changes in the human soleus stretch reflex. Mrachacz-Kersting, N., Kersting, UG., de Brito Silva, P., et al.[2020]

In a study involving normal humans, down-conditioning of the soleus H-reflex led to a significant reduction of 27.2% in reflex size, but this did not translate into long-term changes in the medial and lateral gastrocnemius H-reflexes or improvements in locomotion.

The results suggest that while task-dependent adaptations occur in normal subjects, they do not lead to the beneficial long-term changes seen in individuals with incomplete spinal cord injury, highlighting a difference in reflex plasticity and its impact on movement between these populations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Operant conditioning of the soleus H-reflex does not induce long-term changes in the gastrocnemius H-reflexes and does not disturb normal locomotion in humans. Makihara, Y., Segal, RL., Wolpaw, JR., et al.[2021]

Ambulatory individuals with cerebral palsy can modulate lower-limb reflexes, as shown by a significant reduction in soleus H-reflex excitability when performing a more complex unilateral standing task, indicating some retained neural control capabilities.

There is a strong positive correlation between refined neural control during walking and the ability to modulate reflex excitability, suggesting that deficits in motor control may impact reflex modulation in this population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Soleus H-reflex modulation in cerebral palsy and its relationship with neural control complexity: a pilot study. Conner, BC., Spomer, AM., Bishe, SSPA., et al.[2023]

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]

References

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

Acquisition of a simple motor skill: task-dependent adaptation and long-term changes in the human soleus stretch reflex. [2020]

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

Operant conditioning of the soleus H-reflex does not induce long-term changes in the gastrocnemius H-reflexes and does not disturb normal locomotion in humans. [2021]

3. Germany pubmed.ncbi.nlm.nih.gov

Soleus H-reflex modulation in cerebral palsy and its relationship with neural control complexity: a pilot study. [2023]

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

Soleus H-reflex operant conditioning changes the H-reflex recruitment curve. [2022]

5. England pubmed.ncbi.nlm.nih.gov

Reduction of spasticity in cerebral palsy using feedback of the tonic stretch reflex: a controlled study. [2019]

6. England pubmed.ncbi.nlm.nih.gov

Evaluation of extensibility, passive torque and stretch reflex responses in triceps surae muscles following serial casting to correct spastic equinovarus deformity. [2019]

7. Switzerland pubmed.ncbi.nlm.nih.gov

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