Role of the SMA During Unimanual and Bimanual Movements Preparation: the Mirror Movements Paradigm
Condition: Congenital Mirror Movements
Study type: Interventional

Summary: 
      The aim of the project is to study the role of secondary motor area (more precisely the
      supplementary motor area, or SMA) during unimanual and bimanual voluntary movements
      externally (cue) or internally (subject's choice) triggered. In that view, we will study 3
      experimental groups :

        -  a group of healthy volunteers (control group)

        -  the same group of healthy volunteers after a transient inactivation of the SMA (by the
           aim of repetitive trans cranial magnetic stimulation or TMS)

        -  a group of patients suffering from congenital mirror movements who are suspected to
           present a dysfunction of the SMA (according to our previous results) In each of these
           groups, by the aim of a serial reaction time task, we will study the influence of a SMA
           stimulation on the excitability of the primary motor cortex (M1) during the preparation
           of a voluntary movement (unimanual or bimanual). This will allow us to assess the
           communication between the SMA and M1 during movement preparation. Using the same task in
           functional imagery, we will study the activation's pattern of primary and secondary
           motor areas during movement preparation. This multimodal approach should allow us to
           better understand the synergistic functioning of these different structures involved in
           movement preparation. An other interesting aspect will be to determine the role of these
           structures in movement lateralization. Eventually, our results might allow us to precise
           to role of the motor preparation's dysfunction in the genesis of congenital mirror
           movements.

      In the first place, this study aims at a better understanding of the cerebral physiology of
      movement preparation (which is not well known) using the mirror movements paradigm as a
      dysfunction model (according to our previous results). According to our hypothesis, there is
      a strong link between the SMA and M1 during movement preparation. This hypothesis will be
      assessed by the use of the same experimental task with combined neurophysiological and
      neuroimaging approaches, thus increasing the validity of the results obtained.

      A secondary aim of this protocol is to precise the role of motor planning dysfunction in
      patients with congenital mirror movements. A better understanding of the mechanisms
      responsible for this condition is necessary in a medium-term therapeutic prospect.
    


Intervention name(s): Healthy volunteers; Congenital mirror movements
Intervention type(s): Other; Other
Intervention description(s): Morphological and functional brain MRI; transcranial magnetic stimulation; Morphological and functional brain MRI; transcranial magnetic stimulation
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Congenital mirror movements; SMA; Movement preparation; Movement lateralization; MRI; Transcranial magnetic stimulation