Observational Learning in Stroke Patients
Condition: Stroke
MeSH terms: Stroke
Study type: Observational

Summary: 
      This study will determine how people who have had a stroke learn to perform a movement by
      observation, as compared with people who have not had a stroke. Normally, a person learns a
      new hand movement automatically by observing the movement performed by others. Improvement
      with practice also relies on visual feedback. This "observational training" - i.e., the
      repeated observation of a movement - is sufficient for normal individuals to learn a
      movement. This study will examine brain activity related to motor learning in stroke patients
      and in healthy control subjects to see whether stroke patients process visual-motor
      information the same way normal subjects do.

      Normal volunteers and stroke patients between 18 and 75 years of age may be eligible for this
      study. Patients must have had paralysis on one side of the body due to a stroke that occurred
      at least 3 months before entering the study. Candidates who have not had a recent health
      screening will have a clinical and neurological examination.

      Participants undergo the following procedures:

        -  Brain magnetic resonance imaging (MRI), if one has not been done recently. This test
           uses a strong magnetic field and radio waves to obtain images of body organs and
           tissues. The subject lies on a table that can slide in and out of the cylindrical
           scanner and wears earplugs to muffle loud noises caused by switching of magnetic fields.
           Scanning time varies from 20 minutes to 3 hours, with most sessions lasting 45 to 90
           minutes.

        -  Task training. The subject practices the task to be performed during functional MRI (see
           below). The subject makes finger tapping movements, then watches finger movements on a
           video screen for several minutes, during which time the movie stops from time to time
           without warning. When the movie stops, the subject must reproduce the last finger
           movement that appeared on the screen. During this session, the electrical signals of the
           subject's forearm muscles are recorded at the skin surface. This session lasts up to 3
           hours.

        -  Functional MRI. The subject undergoes MRI scanning while performing the same tasks done
           in the training session. This session lasts about 3 hours.
    

Detailed description: 
      In normal subjects, the learning of new hand movements initially relies on the automatic
      ability to elaborate a motor plan from the simple observation of movements performed by
      others. The improvement of motor performance during practice also relies on a correct
      visuomotor processing of visual feedback and it has been demonstrated that the repeated
      observation of a gesture, named observational training is sufficient to induce motor
      learning. However, it is not known if stroke patients process visuomotor information in the
      same manner as normal subjects.

      Objectives:

      The purpose of this protocol is to determine the pattern of brain activations related to
      motor learning induced by observational training in stroke patients as compared to normal
      volunteers. We hypothesize that observational motor learning in stroke patients will rely on
      an increased activity in premotor cortex as compared to normal volunteers.

      Study population:

      This protocol will include chronic stroke patients with subcortical lesions and good motor
      recovery from an initial upper-limb paresis, and a control population of age and gender
      matched normal volunteers.

      Design:

      We will conduct a functional MRI (fMRI) experiment assessing observational training of finger
      sequences. Three conditions of finger sequences will be compared: 1) a sequence visually
      trained during the fMRI session, 2) a non-trained sequence (control 1), and 3) a sequence
      visually trained before the fMRI session (control 2). The fMRI session will be split into 3
      separate runs. The first run will assess brain activity related to the motor performance of
      the 3 finger sequences. The second run will explore the brain activity during observational
      training of the sequence. The third run will re-assess the brain activity related to the
      motor performance of the 3 finger sequences.

      Outcome measures:

      The endpoint measure of the experiment will be an increase in the number of activated voxels
      in premotor cortex during the motor learning induced by observational training in the stroke
      patients as compared to normal volunteers.
    

Keywords: Brain Plasticity; Functional MRI; Finger Movement; Rehabilitation; Improvement; Stroke; Motor Recovery; Observation; fMRI; Healthy Volunteer; HV