Clinical Trials Logo

Clinical Trial 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.


Clinical Trial Description

The purpose of this study is to investigate neuromodulation as new approach to enhance rehabilitation for people who have upper limb movement impairment after neurological injury such as stroke or spinal cord injury. Emerging evidence demonstrates that animals and people can exert control over the level of excitability in neural pathways 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. Behaviors that are rewarded with positive reinforcement are displayed more frequently. In recent years, operant conditioning has been applied to spinal reflex responses in mice, rats, monkeys and people. Evidence suggests that it is possible to increase or decrease a neural circuit's excitability, by electrically stimulating a nerve or an area of the brain, then recording the muscle response and rewarding responses that are within a desirable range. This may alter the level of resting muscle tone, as well the muscle's contribution to intentional movements and its readiness to respond to unexpected perturbations. To date, only one research group has applied operant conditioning to improve motor performance in people. Their work has focused on modifying spinal reflexes for a lower limb muscle and the effects on walking. In the proposed project, we will expand the use of operant conditioning to muscles of the upper limb and to people with movement impairment following stroke and spinal cord injury, and to another neural pathway in addition to the spinal reflex. This study will include procedures necessary to measure excitability of the nervous system at the level of the spinal cord and at the level of the brain. Spinal reflex excitability will be quantified by electrically stimulating a peripheral nerve and recording the muscle response (ie. the H-reflex) with electromyography. Excitability of the motor pathway from brain to muscle (the corticospinal tract) will be quantified by stimulating a specific area of the brain (the motor cortex) with transcranial magnetic stimulation, and recording the muscle response (ie. The motor evoked potential) with electromyography. In addition, upper limb movement impairment will be assessed by measuring muscle tone, sensation, ability to generate force, and performance on a computer-based wrist motor control task. In subjects who have neurological conditions, upper limb function will be assessed using standardized tests, including the Fugl-Meyer a assessment of the Upper Extremity, the Action Research Arm Test, and the Box and Blocks Test. This study will test the effectiveness of operant conditioning as an intervention to modify neural excitability. After baseline testing, subjects will participate in up to 12 sessions of sham intervention followed by up to 24 sessions of real operant conditioning intervention. Each session will include 225 trials (3 sets of 75), lasting about 30 minutes. For each trial during real intervention, a stimulus will be delivered while the subject maintains a low level muscle contraction, the muscle's response to stimulation will be recorded, and immediate feedback will be displayed on a computer screen, showing the subject whether their muscle response was within the desired range or not. For example, a green bar will appear if the muscle response was 'good', otherwise a red bar will appear. The subject's 'percent success' also will be displayed and updated after each trial. During sham intervention, all procedures will be identical except that no feedback will be provided to the subject, and there will be no instructions to either increase or decrease their muscle responses. In healthy people, we will aim to shift spinal reflex excitability (H-reflexes) of an upper extremity muscle either upward or downward, expanding on previous findings showing those effects in a lower limb muscle, with no effect on normal movement ability (Thompson et al., 2009, Makihara et al., 2014). Also in healthy people, we will aim to shift excitability of the pathway from brain to muscle either upward or downward, using operant conditioning of motor evoked potentials. Only one prior study (Majid et al., 2015) has demonstrated a downward shift, and the first studies investigating the ability to increase motor evoked potentials currently are in progress. People with neurological conditions often have abnormally increased spinal reflex excitability affecting certain muscles, resulting in increased tone, stiffness, and difficulty moving. Therefore, we will aim to reduce spinal reflex excitability in over-active muscles, by eliciting H-reflexes and rewarding responses that are below a threshold. In addition, people with neurological conditions often have disrupted connections from brain to muscle, resulting in weakness (diminished ability to generate force). Therefore, we will aim to increase excitability of the pathway from brain to muscle, by eliciting motor evoked potentials and rewarding responses that are above a threshold. ;


Study Design


Related Conditions & MeSH terms


NCT number NCT03461159
Study type Interventional
Source University of Iowa
Contact Stacey L DeJong, PhD, PT
Phone 319-335-6842
Email stacey-dejong@uiowa.edu
Status Recruiting
Phase N/A
Start date June 8, 2018
Completion date June 30, 2024

See also
  Status Clinical Trial Phase
Recruiting NCT06052553 - A Study of TopSpin360 Training Device N/A
Completed NCT05511077 - Biomarkers of Oat Product Intake: The BiOAT Marker Study N/A
Recruiting NCT04632485 - Early Detection of Vascular Dysfunction Using Biomarkers From Lagrangian Carotid Strain Imaging
Completed NCT05931237 - Cranberry Flavan-3-ols Consumption and Gut Microbiota in Healthy Adults N/A
Completed NCT04527718 - Study of the Safety, Tolerability and Pharmacokinetics of 611 in Adult Healthy Volunteers Phase 1
Terminated NCT04556032 - Effects of Ergothioneine on Cognition, Mood, and Sleep in Healthy Adult Men and Women N/A
Completed NCT04107441 - AX-8 Drug Safety, Tolerability and Plasma Levels in Healthy Subjects Phase 1
Completed NCT04998695 - Health Effects of Consuming Olive Pomace Oil N/A
Completed NCT04065295 - A Study to Test How Well Healthy Men Tolerate Different Doses of BI 1356225 Phase 1
Completed NCT01442831 - Evaluate the Absorption, Metabolism, And Excretion Of Orally Administered [14C] TR 701 In Healthy Adult Male Subjects Phase 1
Terminated NCT05934942 - A Study in Healthy Women to Test Whether BI 1358894 Influences the Amount of a Contraceptive in the Blood Phase 1
Recruiting NCT05525845 - Studying the Hedonic and Homeostatic Regulation of Food Intake Using Functional MRI N/A
Completed NCT05515328 - A Study in Healthy Men to Test How BI 685509 is Processed in the Body Phase 1
Completed NCT05030857 - Drug-drug Interaction and Food-effect Study With GLPG4716 and Midazolam in Healthy Subjects Phase 1
Completed NCT04967157 - Cognitive Effects of Citicoline on Attention in Healthy Men and Women N/A
Recruiting NCT04494269 - A Study to Evaluate Pharmacokinetics and Safety of Tegoprazan in Subjects With Hepatic Impairment and Healthy Controls Phase 1
Recruiting NCT04714294 - Evaluate the Safety, Tolerability and Pharmacokinetics Characteristics of HPP737 in Healthy Volunteers Phase 1
Completed NCT04539756 - Writing Activities and Emotions N/A
Recruiting NCT04098510 - Concentration of MitoQ in Human Skeletal Muscle N/A
Completed NCT03308110 - Bioavailability and Food Effect Study of Two Formulations of PF-06650833 Phase 1