Neurophysiology, Physiology
Conditions
Keywords
COPD, Transcranial magnetic stimulation, Motor-evoked potentials, Muscle weakness, Interhemispheric, Inhibition
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.
Interventions
OTHERTranscranial magnetic stimulation (TMS)
Evaluations by TMS
Sponsors
5 Santé
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
COPD Patients vs. Controls
Eligibility
Sex/Gender
ALL
Age
40 Years to 75 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Ipsilateral excitability ratio : rest - 50% mvic | Baseline | Ratio of ipsilateral excitability. Measured at rest, and during a 50% max. isometric contraction. Then, ipsilateral excitability ratio = rest / 50% \* 100. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Ipsilateral inhibition ratio : rest - 50% mvic | Baseline | 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. |
| Interhemispheric inhibition | Baseline | Interhemispheric inhibition, from contralateral to ipsilateral motor cortex, using reference method from Ferbert et al., 1992. |
| Relationship between inter hemispheric inhibition and voluntary strength | Baseline | Correlation coefficient between inter hemispheric inhibition and maximal isometric force production |
| S100B and GFAP | Baseline | Serum concentrations of S100B and GFAP proteins, brain lesions markers |
Countries
France
Outcome results
None listed