Study of Cortical Activation During Hand and Shoulder Movements in Healthy Subjects
Condition: Healthy
Study type: Observational

Summary: 
      Characterization of cortical activation patterns during movements in healthy adults may help
      our understanding of how the injured brain works. Upper limb motor tasks are commonly used to
      assess impaired motor function and to predict recovery in individuals with neurological
      disorders such as stroke. This study aimed to explore cortical activation patterns associated
      with movements of the hand and shoulder using functional near-infrared spectroscopy (fNIRS).
      The investigators hypothesized that the activation pattern observed with fNIRS would differ
      for shoulder and hand movements. More specifically, the investigators hypothesized that the
      cerebral activation during hand movements would mainly involve the contralateral hemisphere,
      particularly the lateral part of primary motor cortex; whereas activation during shoulder
      movements would be more medial and more extensive than that of the hand.
    

Detailed description: 
      Stroke is a leading cause of chronic disability worldwide in adults. Upper extremity (hand
      and arm) impairments are especially prevalent after stroke and cause lasting disabilities.
      Functional reorganization of the motor cortex may occur in both the ipsilesional and
      contralesional hemispheres. Thus, knowledge of brain activation patterns during execution of
      a movement is important both for neuroscience and neurorehabilitation.

      The use of brain imaging techniques for post-stroke follow-up is valuable for understanding
      the mechanisms of cerebral recovery. Functional Near-Infrared Spectroscopy (fNIRS) is a
      non-invasive technique that assesses neural activation through the measurement of cortical
      oxygenated and deoxygenated hemoglobin concentrations during motor tasks in a natural.

      As remapping of the sensorimotor cortex after stroke with hand impairment can involve the
      territory of the elbow or shoulder, the investigators aimed to determine if the cortical
      activation of these regions (hand and shoulder) could be distinguished by fNIRS recordings in
      healthy subjects. The investigators hypothesized that the activation pattern observed with
      fNIRS would differ for shoulder and hand movements. More specifically, the investigators
      hypothesized that the cerebral activation during hand movements would mainly involve the
      contralateral hemisphere, particularly the lateral part of primary motor cortex; whereas
      activation during shoulder movements would be more medial and more extensive than that of the
      hand, involving the contralateral premotor region and supplementary motor cortex. If these
      three cortical regions could be distinguished by fNIRS, this technique could be used to
      measure spontaneous motor recovery and rehabilitation-induced recovery after stroke.

      The investigations will be carried out by the principal investigator or by specialized
      technicians from the neurology functional exploration department.

      Each acquisition has a duration of 920 seconds, it begins with a rest period of 120 seconds,
      which corresponds to the baseline.

      For each condition the movements are performed at a frequency of 0.5 Hz which seems to be the
      optimal frequency for observing cortical activation using a metronome. Each movement is
      therefore performed 10 times per block.

      The order of placing the various conditions will be balanced. Between periods of movement,
      the subject is in a resting position for 30 seconds.

      The "movement" and "rest" instructions are given at the start of each phase.

      The protocol has 2 conditions:

        -  Shoulder task

        -  Hand task

      After recruiting the participants, the study investigator will check the inclusion and
      non-inclusion criteria.

      On the day of the first acquisition, the subject will present to the neurology department at
      the time of his appointment.

      Then the fNIRS acquisition headset (Brite 24) will be installed by a specialized technician
      and the procurement instructions will be given.

      The acquisition is then carried out. The helmet is only removed at the end of the acquisition
    

Intervention name(s): Hand and shoulder task
Intervention type(s): Device
Intervention description(s): Hand task: the participant is seated on a chair facing a table, both hands resting on the table. The participant is asked, for each block of 10 seconds, to perform flexion / extension movements of the fingers of the right hand at 0.5 Hz.
Shoulder task: the participant is seated on a chair facing a table, both hands resting on the table. The participant is asked, for each block of 10 seconds, to perform alternating movement of abduction and adduction of the right shoulder at 0.5 Hz with the elbow flexed.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        right handed healthy subjects aged between 18 and 40
      
Keywords: cortical activation; functional near-infrared spectroscopy; upper limb; motricity