Gait Mate: Examining Neural Networks Engaged During Lower Extremity Movement in the MRI
Condition: Stroke; Motor Activity
Study type: Observational

Summary: 
      Less than 50% of stroke survivors progress to independent community ambulation. Even among
      the stroke survivors who achieve independent ambulation, significant residual deficits
      persist in balance and gait speed, with 60% of persons post-stroke reporting limitations in
      mobility related to walking.Consequently maximizing recovery of locomotor function is the
      focus of neurorehabilitation efforts worldwide. A recently completed clinical trial from
      members of this investigative team demonstrated that 6 weeks of treadmill training elicits
      substantial improvements in over ground walking speed and symmetry in persons following
      stroke. Consistent with the goals of the South Carolina Stroke Rehabilitation Research Center
      (SCSRRC) and NIH Brain Initiative, the investigators now plan to investigate the effects
      treadmill-assisted gait training have on cortical control of bipedal movement in chronic
      stroke patients. Although previous investigators have assessed neural activity during
      simulated walking using motor imagery, motor imagery does not simulate the typical sensory
      feedback associated with active movement. To move the field forward, it is necessary to
      measure active bipedal movement in the MR-environment in healthy volunteers, before moving
      forward in stroke patients.
    

Detailed description: 
      The overarching goal of this Discovery Proposal is to evaluate neural activity during
      unipedal and bipedal movement in a cohort of healthy individuals (Aim 1).

      The rigor and reproducibility will be evaluated by comparing the results of 1) active
      movement -Bipedal with 2) active movement -unipedal 4 and 3) imagined movement.

      Dependent measures include: 1) head motion during the fMRI task, 2) BOLD signal in the
      ipsilateral and contralateral motor cortex during the fMRI task, 3) force applied during the
      fMRI task, and 4) participant feedback using a modified version of the Presence Questionnaire
      (a standard tool to assess ecological validity of virtual environments.

      Each Aim has a development and evaluation aspect. Through this 1 year proposal the
      investigators will determine if the bipedal fMRI protocol (active movement) is able to engage
      neural networks more robustly (e.g. greater effect size) than bipedal imagery alone in
      Healthy Volunteers.

      Specific Aim #1: Healthy volunteers: The investigators will test the hypothesis that with
      active bipedal movement there will be 1) no difference in head movement, but 2) greater motor
      cortex BOLD signal, 3) smoother force exchange between the feet, 4) higher participant
      satisfaction than unipedal movement or motor imagery alone. This sample size was selected
      based on a prior publication of imagined movement. The outcome of this aim may result in the
      first publication in the field to evaluate bipedal movement in an MR-environment.
    

Intervention name(s): GAITRite assessment
Intervention type(s): Device
Intervention description(s): The fMRI Bipedal Paradigm will allow investigators to study the effects treadmill-assisted gait training have on cortical control of bipedal movement in chronic stroke patients.
Other intervention name(s): fMRI Bipedal Paradigm
Sampling method: Non-Probability Sample
Study population: 
        Healthy volunteers will be screened for eligibility who are right hand dominant.
      
Keywords: fMRI; BOLD Signal; Rehabilitation