Transcutaneous Auricular Vagus Nerve Stimulation to Enhance Motor Learning

Study Overview
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Brief Summary
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Vagus nerve stimulation (VNS) activates neural pathways leading to the release of chemicals that promote plasticity and learning. Previous work has shown that the auricular branch of the vagus nerve innervates landmarks on the external ear. Work from the PI's laboratory has shown that electrical current applied to the external ear activates neural pathways implicated in the therapeutic effects of VNS. The broad objective of this project is to better understand physiological mechanisms that are modulated by auricular stimulation and its potential to enhance motor learning.

Official Title
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Transcutaneous Auricular Vagus Nerve Stimulation: Mechanisms and Therapeutic Potential

Conditions
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Neurological Injury, Motor Disorders, Paresis

Intervention / Treatment
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* Other: Transcutaneous Vagus Nerve Stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: (For prospective subjects diagnosed with stroke) Confirmed diagnosis of a single stroke at least six months prior to participation Exclusion Criteria: History of vestibular disorders or dizziness Diagnosis of neurological disorders affecting movement Ocular disease and/or impairment in more than one eye Pregnant or expecting to become pregnant Difficulty maintaining alertness and/or remaining still

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Sham-controlled
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Transcutaneous Vagus Nerve Stimulation<br>Transcutaneous vagus nerve stimulation paired with visuomotor task training | Other: Transcutaneous Vagus Nerve Stimulation<br>* Visuomotor task training with transcutaneous stimulation targeting landmark that activates biomarker<br>|
| Placebo Comparator: Transcutaneous Stimulation (Sham)<br>Transcutaneous stimulation paired with visuomotor task training | Other: Transcutaneous Vagus Nerve Stimulation<br>* Visuomotor task training with transcutaneous stimulation targeting landmark that activates biomarker<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Precision grip stability (coefficient of variation or root-mean-square error) | The ability to stabilize precision grip according to target force and/or preload force will be quantified by calculating coefficient of variation (CV) or root-mean-square error (RMSE) which characterize variability in relation to mean force or target force. | 1 month post training | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Force signal composition (Fourier transform) | The force signal oscillates at various frequencies and will be decomposed with a Fourier transform to quantify the relative contribution of higher frequencies. | 1 month post training |