Metaplasticity in Human Pharyngeal Motor Cortex

Study Overview
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Brief Summary
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The purpose of the study is to determine the effects of giving 2 doses of brain stimulation through repetitive transcranial magnetic stimulation (rTMS) on swallowing neurophysiology (brain function) in healthy adults.

Detailed Description
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Recent studies have suggested that repetitive transcranial magnetic stimulation (rTMS), which is a well-established and tried and tested non-invasive (no surgical procedures involved) brain stimulation technique that can vary brain activities, may be used as a treatment for patients with swallowing difficulties. However, results have also showed that the response to the treatment is different among individuals. A possible explanation for this variation is related to the brain's level of activity preceding rTMS. The hypothesis of this study is that this variation may be minimized by regulating the brain state with an additional dose of rTMS prior to the intended rTMS session (preconditioned rTMS). This may subsequently improve the outcomes of rTMS. Therefore, this study aims to better regulate the response of the brain to rTMS. The findings of this study will provide the basis for future development of optimal rTMS treatment protocols for patients with swallowing difficulties.

Official Title
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Inducing Metaplasticity in Human Pharyngeal Motor Cortex Through Preconditioned Repetitive Transcranial Magnetic Stimulation (rTMS)

Conditions
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Deglutition, Physiology

Intervention / Treatment
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* Device: rTMS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy volunteers aged 18 years old or above; and No medical complications or significant past medical history Exclusion Criteria: History of epilepsy; Previous history of neurosurgery; Previous swallowing problem; Implanted brain electrodes, cardiac pacemaker; or Use of medications (predominantly taking multiple anti-depressants) that lower neural threshold

Ages Eligible for Study
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Minimum Age: 18 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: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sham Comparator: Sham 1Hz rTMS--5Hz rTMS<br>Participants will receive sham 1Hz rTMS, then immediately followed by 5Hz rTMS. | Device: rTMS<br>* rTMS is a non-invasive brain stimulation technique. It can regulate brain activities with electrical pulses sent to the brain through electromagnetic induction.<br>|
| Experimental: 1Hz rTMS--5Hz rTMS<br>Participants will receive 1Hz rTMS, then immediately followed by 5Hz rTMS. | Device: rTMS<br>* rTMS is a non-invasive brain stimulation technique. It can regulate brain activities with electrical pulses sent to the brain through electromagnetic induction.<br>|
| Experimental: 1Hz rTMS--30-minute break--5Hz rTMS<br>Participants will receive 1Hz rTMS, then followed by 30 minutes break, then followed by 5Hz rTMS. | Device: rTMS<br>* rTMS is a non-invasive brain stimulation technique. It can regulate brain activities with electrical pulses sent to the brain through electromagnetic induction.<br>|
| Experimental: 1Hz rTMS--60-minute break--5Hz rTMS<br>Participants will receive 1Hz rTMS, then followed by 60 minutes break, then followed by 5Hz rTMS. | Device: rTMS<br>* rTMS is a non-invasive brain stimulation technique. It can regulate brain activities with electrical pulses sent to the brain through electromagnetic induction.<br>|
| Sham Comparator: Sham 5Hz rTMS--1Hz rTMS<br>Participants will receive sham 5Hz rTMS, then immediately followed by 1Hz rTMS. | Device: rTMS<br>* rTMS is a non-invasive brain stimulation technique. It can regulate brain activities with electrical pulses sent to the brain through electromagnetic induction.<br>|
| Experimental: 5Hz rTMS--1Hz rTMS<br>Participants will receive 5Hz rTMS, then immediately followed by 1Hz rTMS. | Device: rTMS<br>* rTMS is a non-invasive brain stimulation technique. It can regulate brain activities with electrical pulses sent to the brain through electromagnetic induction.<br>|
| Experimental: 5Hz rTMS--45-minute break--1Hz rTMS<br>Participants will receive 5Hz rTMS, then followed by 45 minutes break, then followed by 1Hz rTMS. | Device: rTMS<br>* rTMS is a non-invasive brain stimulation technique. It can regulate brain activities with electrical pulses sent to the brain through electromagnetic induction.<br>|
| Experimental: 5Hz rTMS--90-minute break--1Hz rTMS<br>Participants will receive 5Hz rTMS, then followed by 90 minutes break, then followed by 1Hz rTMS. | Device: rTMS<br>* rTMS is a non-invasive brain stimulation technique. It can regulate brain activities with electrical pulses sent to the brain through electromagnetic induction.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pharyngeal motor evoked potentials (PMEPs) | Motor evoked potentials from the pharynx will be elicited by single pulse transcranial magnetic stimulation and recorded. | Change from baseline up to 150 minutes after rTMS | 
| Thenar (hand) motor evoked potentials (TMEPs) | Motor evoked potentials from the hand will be elicited by single pulse transcranial magnetic stimulation and recorded. | Change from baseline up to 150 minutes after rTMS | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Non-invasive brain stimulation, Swallowing, Metaplasticity