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Operant Conditioning for Neuromodulation

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ClinicalTrials.gov Identifier: NCT03461159
Recruitment Status : Recruiting
First Posted : March 9, 2018
Last Update Posted : July 3, 2018
Sponsor:
Collaborator:
Roy J. Carver Charitable Trust
Information provided by (Responsible Party):
Stacey Dejong, University of Iowa

Brief Summary:
Emerging evidence demonstrates that animals and people can exert control over the level of excitability in spinal and corticospinal neural circuits that contribute to movement. This discovery has important implications, as it represents a new strategy to improve motor control in people of all ability levels, including those with neurological conditions. Operant conditioning is a well-studied mechanism of learning, in which the modification of a behavior can be brought about by the consequence of the behavior, and reinforcement causes behaviors to become more frequent. In recent years, operant conditioning has been applied to spinally-mediated reflex responses in mice, rats, monkeys and people. By electrically stimulating a peripheral nerve, recording the muscle response, and rewarding responses that are within a desirable range, it is possible to increase or decrease the neural circuit's excitability. This may alter the level of resting muscle tone and spasticity, as well the muscle's contribution to planned movements and responses to unexpected events. Operant conditioning of spinal reflexes has been applied to a lower limb muscle in healthy people and those with spinal cord injuries. In this project, we will expand the use of operant conditioning to muscles of the upper limb, demonstrating feasibility and efficacy in healthy people and people post-stroke. We will determine whether operant conditioning can be used to decrease excitability of spinal reflexes that activate a wrist flexor muscle. Additionally, in a separate group of healthy people, we will determine whether operant conditioning can be used in a similar way to increase corticospinal excitability. We will stimulate the motor cortex with transcranial magnetic stimulation to elicit motor evoked potentials in the same wrist flexor muscle, and will reward responses that exceed a threshold value. We will examine the effects of these interventions on motor control at the wrist, using an innovative custom-designed cursor-tracking task to quantify movement performance. We will determine whether changes in spinal reflex excitability or corticospinal excitability alter motor control. The overall goal of this research is to develop a new, evidence-based strategy for rehabilitation that will improve recovery of upper limb function in people after stroke.

Condition or disease Intervention/treatment Phase
Stroke Healthy Other: Operant conditioning of H-reflexes Other: Operant conditioning of motor evoked potentials Not Applicable

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 60 participants
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Operant Conditioning of Spinal Reflexes and Motor Evoked Potentials
Actual Study Start Date : June 8, 2018
Estimated Primary Completion Date : March 2020
Estimated Study Completion Date : March 2020

Arm Intervention/treatment
Experimental: H-reflex conditioning - Healthy
Operant conditioning of H-reflexes in healthy volunteers
Other: Operant conditioning of H-reflexes
Spinal reflex responses will be elicited in a wrist flexor muscle using a peripheral nerve stimulator. During training trials, the size of the participant's response will be shown on a screen and the participant will be asked to decrease the size of the H-reflex response over successive trials. Responses that are below a threshold will be rewarded and those above will not.

Experimental: H-reflex conditioning - Stroke
Operant conditioning of H-reflexes in people post-stroke
Other: Operant conditioning of H-reflexes
Spinal reflex responses will be elicited in a wrist flexor muscle using a peripheral nerve stimulator. During training trials, the size of the participant's response will be shown on a screen and the participant will be asked to decrease the size of the H-reflex response over successive trials. Responses that are below a threshold will be rewarded and those above will not.

Experimental: MEP conditioning - Healthy
Operant conditioning of motor evoked potentials in healthy volunteers
Other: Operant conditioning of motor evoked potentials
Motor evoked potentials will be elicited in a wrist flexor muscle using transcranial magnetic stimulation. During training trials, the size of the participant's response will be shown on a screen and the participant will be asked to increase the size of the MEP response over successive trials. Responses that are above a threshold will be rewarded and those below will not.

Experimental: MEP conditioning - Stroke
Operant conditioning of motor evoked potentials in people post-stroke
Other: Operant conditioning of motor evoked potentials
Motor evoked potentials will be elicited in a wrist flexor muscle using transcranial magnetic stimulation. During training trials, the size of the participant's response will be shown on a screen and the participant will be asked to increase the size of the MEP response over successive trials. Responses that are above a threshold will be rewarded and those below will not.




Primary Outcome Measures :
  1. Maximum H-reflex amplitude of target muscle (wrist flexor) [ Time Frame: baseline, before and after up to 8 weeks of operant conditioning and follow up 3 months later ]
    After operant conditioning of H-reflexes, the pre-training vs post-training change in the maximum H-reflex, identified using recruitment curves, will be the primary outcome measure.

  2. Motor evoked potential amplitude of target muscle (wrist flexor) [ Time Frame: baseline, before and after up to 8 weeks of operant conditioning and follow up 3 months later ]
    After operant conditioning of motor evoked potentials, the pre-training vs post-training change in the MEP amplitude for the target muscle will be the primary outcome measure. Stimulus intensity will be kept constant during pre and post testing (e.g. 110% of the baseline resting motor threshold).


Secondary Outcome Measures :
  1. Maximum H-reflex amplitude of an antagonist muscle (wrist extensor) [ Time Frame: baseline, before and after up to 8 weeks of operant conditioning and follow up 3 months later ]
    pre-training vs post-training change in the maximum H-reflex of the antagonist muscle, identified using recruitment curves

  2. Motor evoked potential amplitude of an antagonist muscle (wrist extensor) [ Time Frame: baseline, before and after up to 8 weeks of operant conditioning and follow up 3 months later ]
    Pre-training vs post-training change in the motor evoked potential amplitude for the antagonist muscle.

  3. Wrist motor control total error score [ Time Frame: baseline, before and after up to 8 weeks of operant conditioning and follow up 3 months later ]
    Wrist motor control will be assessed using a novel instrumented device and a computer-based force-tracking task that requires a high level of precise motor control at the wrist.

  4. Maximum voluntary isometric contraction [ Time Frame: baseline, before and after up to 8 weeks of operant conditioning and follow up 3 months later ]
    Maximum wrist flexion force production

  5. Action Research Arm Test [ Time Frame: baseline, before and after up to 8 weeks of operant conditioning and follow up 3 months later ]
    For participants with stroke only, this standardized test will be used to quantify upper limb function.

  6. Fugl-Meyer Assessment of the Upper Extremity [ Time Frame: baseline, before and after up to 8 weeks of operant conditioning and follow up 3 months later ]
    For participants with stroke only, this standardized test will be used to quantify upper limb impairment.



Information from the National Library of Medicine

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Ages Eligible for Study:   21 Years to 90 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria for Healthy Group:

  • Able and willing to provide informed consent
  • Normal function of both upper extremities
  • Generally in good health

Exclusion Criteria for Healthy Group:

  • Any self-reported disease or disorder that might affect this study, including neurologic, psychiatric, muscular, orthopedic, cardiac, vascular, pulmonary, hematologic, infectious, immune, gastrointestinal, urogenital, integumentary, oncologic, or endocrine conditions
  • Any self-reported or demonstrated loss of sensation, passive range of motion, or motor function affecting any part of the upper limb on either side

Inclusion Criteria for Stroke Group:

  • Able and willing to provide informed consent
  • Subcortical ischemic stroke OR incomplete spinal cord injury, diagnosed by a neurologist at least 3 months before enrollment
  • Upper limb sensorimotor impairment on one or both sides, as indicated by a score of 10 to 56 out of 66 points on the Fugl-Meyer Assessment of the Upper Extremity
  • Cognitive ability that is normal or only mildly impaired, as indicated by a score of 9 or less on the Short Blessed Test
  • Normal receptive and expressive language abilities, as indicated by a score of 0 on the Best Language item of the National Institutes of Health Stroke Scale

Exclusion Criteria for Stroke Group:

  • Any self-reported or medically documented disease or disorder that might affect this study, including other neurologic conditions besides stroke or spinal cord injury, psychiatric, muscular, orthopedic, cardiac, vascular, pulmonary, hematologic, infectious, immune, gastrointestinal, urogenital, integumentary, oncologic, or endocrine conditions
  • Diagnosis of hemorrhagic stroke or hemorrhagic conversion
  • Diagnosis of an infarct affecting the motor cortex

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03461159


Contacts
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Contact: Stacey L DeJong, PhD, PT 319-335-6842 stacey-dejong@uiowa.edu
Contact: Kim A Streeby 319-384-4735 kimberly-streeby@uiowa.edu

Locations
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United States, Iowa
University of Iowa Recruiting
Iowa City, Iowa, United States, 52242
Contact: Stacey L DeJong, PhD, PT    319-335-6842    stacey-dejong@uiowa.edu   
Contact: Kim A Streeby    319-384-4735    kimberly-streeby@uiowa.edu   
Principal Investigator: Stacey L DeJong, PhD, PT         
Sponsors and Collaborators
Stacey Dejong
Roy J. Carver Charitable Trust
Investigators
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Principal Investigator: Stacey L DeJong, PhD, PT University of Iowa

Publications:
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Responsible Party: Stacey Dejong, Assistant Professor, University of Iowa
ClinicalTrials.gov Identifier: NCT03461159     History of Changes
Other Study ID Numbers: 201712733
First Posted: March 9, 2018    Key Record Dates
Last Update Posted: July 3, 2018
Last Verified: July 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Keywords provided by Stacey Dejong, University of Iowa:
operant conditioning
H-reflex
motor evoked potential
transcranial magnetic stimulation
motor control