Functional Implication of Corpus Callosum in Voluntary Strength in COPD Patients

Study Overview
=================
Brief Summary
-----------------
Patients with COPD have lower capability of activating their muscles. At the cortical level, force production is not only controlled by contralateral primary motor cortex but also by ipsilateral motor cortex. The aim of this study is to determine whether ipsilateral areas are functionally impaired in COPD.

Detailed Description
-----------------
Chronic obstructive pulmonary disease (COPD) patients exhibit not only respiratory symptoms but also a peripheral muscular weakness. This weakness is characterized by a loss in strength, harmful for the patients' life quality and vital prognosis (Swallow et al., 2007). Even if many studies have enlightened damages at a peripheral level, the muscular atrophy itself cannot totally explain the loss in force (Menon et al., 2012). Furthermore, the contractile properties of COPD muscles fibres are preserved (Debigare et al., 2003). Consequently, peripheral muscle weakness cannot only be explained by peripheral factors and central structures must be investigated. At the central level, it is admitted that force production is controlled by the activation of contralateral motor areas. In COPD, these areas were found to be less activated than in controls during force production (Alexandre et al., 2014). However, recent studies bring the evidence that ipsilateral motor areas are also mobilized to cope demand during such task. The activation of ipsilateral areas is possible through inter hemispheric pathways, as the corpus callosum. Recently, the integrity of the corpus callosum have been linked to the capability of activating the ipsilateral motor cortex (Chiou et al., 2014) during force production. This is of concern knowing that several studies reported white matter lesions in the brain of COPD patients (Dodd et al, 2012) and more precisely in regions containing the corpus callosum (Lahousse et al., 2013). Therefore, we hypothesize that COPD patients have a lower capability of activating their ipsilateral motor cortex during force production compared to controls.

Official Title
-----------------
Functional Implication of Corpus Callosum in Voluntary Strength in COPD Patients

Conditions
-----------------
Neurophysiology, Physiology

Intervention / Treatment
-----------------
* Other: Transcranial magnetic stimulation (TMS)


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Health insurance Patients : COPD Gold II-IV Exclusion Criteria: Pregnant women Seizures Unable to give written consent Metalic object above shoulders Dermatological issue concerning surface electrodes Caffeine consumption > 4 coffee / day Neurological disorders Opioid-based treatment Patients : recent exacerbation (< 4 weeks) Patients : rehabilitation in previous 1 year

Ages Eligible for Study
-----------------
Minimum Age: 40 Years
Maximum Age: 75 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Interventional Model Description: COPD Patients vs. Controls
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: COPD patients group<br>COPD patients undergoing transcranial magnetic stimulation (TMS) evaluations. | Other: Transcranial magnetic stimulation (TMS)<br>* Evaluations by TMS<br>|
| Active Comparator: Controls group<br>Healthy matched controls undergoing transcranial magnetic stimulation (TMS) evaluations. | Other: Transcranial magnetic stimulation (TMS)<br>* Evaluations by TMS<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ipsilateral excitability ratio : rest - 50% mvic | Ratio of ipsilateral excitability. Measured at rest, and during a 50% max. isometric contraction. Then, ipsilateral excitability ratio = rest / 50% * 100. | Baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ipsilateral inhibition ratio : rest - 50% mvic | Ratio of ipsilateral inhibition. Measured at rest, and during a 50% max. isometric contraction. Then, ipsilateral inhibition ratio = rest / 50% * 100. SICI (2ms) method is used to quantify inhibition. | Baseline | 
| Interhemispheric inhibition | Interhemispheric inhibition, from contralateral to ipsilateral motor cortex, using reference method from Ferbert et al., 1992. | Baseline | 
| Relationship between inter hemispheric inhibition and voluntary strength | Correlation coefficient between inter hemispheric inhibition and maximal isometric force production | Baseline | 
| S100B and GFAP | Serum concentrations of S100B and GFAP proteins, brain lesions markers | Baseline | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
COPD, Transcranial magnetic stimulation, Motor-evoked potentials, Muscle weakness, Interhemispheric, Inhibition