Effect of Transcranial Direct Current Stimulation (tDCS) on the Excitability of the Diaphragmatic Primary Motor Cortex

Study Overview
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Brief Summary
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Transcranial direct current stimulation (tDCS) is a non invasive, painless, harmless way to modulate cerebral cortex excitability. It was shown that anodal stimulation increases cortical excitability and the cathodal one decreases it (Nitsche and Paulus, 2000; Lang et al. 2004). To date, there is no data in the literature regarding the effect of tDCS on the corticodiaphragmatic pathways. This preliminary study aims to test and validate the modulating effect of tDCS on the excitability of the primary motor cortex dedicated to the hemi-diaphragms in a sample of healthy subjects, as a prelude to further large studies in patients with paretic hemi-diaphragms. Diaphragmatic motor evoked potentials will be assessed before and after applications of three different modalities of tDCS (anodal, cathodal and placebo).

Detailed Description
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We therefore expect to observe a significant increase of the mean values of the right hemidiaphragm's MEP's amplitudes after application of anodal tDCS compared to the baseline MEP obtained before this treatment.

Official Title
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Modulation de l'excitabilité Des Aires Corticales Motrices Primaires Correspondant Aux hémi Diaphragmes à l'Aide de la tDCS (Transcranial Direct Current Stimulation)

Conditions
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Excitability of Diaphragmatic Primary Motor Cortex

Intervention / Treatment
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* Device: Eldith DC stimulator ( Magstim Company Ltd. UK)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Right handed, Healthy male volunteers Aged ≥ 18 and ≤ 35 years No history of neurological or respiratory disease BMI (body mass index < 30) Exclusion Criteria: Female sex Vulnerable people as defined in the provisions relating to biomedical researches and described in the Code of Public Health. Recent or ongoing use of antibiotic drugs, antidepressants or psychotropic drugs. Recent hospitalization (within 3 months). No affiliation to a social security system.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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Male

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: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Anodal tDCS<br> | Device: Eldith DC stimulator ( Magstim Company Ltd. UK)<br>* Anodal tDCS: Intensity of 2 mA , during 10 min Cathodal tDCS: Intensity of 2 mA , during 10 min Placebo type tDCS: Intensity of 0 mA during 10 min<br>* Other names: Magstim 200 TMS(Magstim Company Ltd.UK);|
| Active Comparator: Cathodal tDCS<br> | Device: Eldith DC stimulator ( Magstim Company Ltd. UK)<br>* Anodal tDCS: Intensity of 2 mA , during 10 min Cathodal tDCS: Intensity of 2 mA , during 10 min Placebo type tDCS: Intensity of 0 mA during 10 min<br>* Other names: Magstim 200 TMS(Magstim Company Ltd.UK);|
| Placebo Comparator: Placebo type tDCS<br> | Device: Eldith DC stimulator ( Magstim Company Ltd. UK)<br>* Anodal tDCS: Intensity of 2 mA , during 10 min Cathodal tDCS: Intensity of 2 mA , during 10 min Placebo type tDCS: Intensity of 0 mA during 10 min<br>* Other names: Magstim 200 TMS(Magstim Company Ltd.UK);|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in the right side hemi-diaphragm's motor evoked potentials (MEPs) before and after applications of three different modalities of tDCS (anodal, cathodal and placebo) upon the left primary motor cortex. | The facilitating effect of tDCS in Anodal stimulation mode (a-tDCS) on the excitability of the left diaphragmatic primary motor cortex would result in a significant increase of the amplitude of the right hemidiaphragm motor evoked potentials (MEPs) (obtained by Transcranial magnetic motor stimulation of the left diaphragmatic primary) after this treatment. | Baseline MEPs (before tDCS), Post 0 MEPs (immediately after tDCS) and Post 10 MEPs (10 min after tDCS). | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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tDCS, Diaphragm, Cortical Excitability, MEPs, TMS