Influence of Area of Brain Damage on Brain Reorganization After Chronic Stroke
Condition: Central Nervous System Disease; Cerebrovascular Accident; Stroke
MeSH terms: Stroke; Nervous System Diseases; Central Nervous System Diseases
Study type: Observational

Summary: 
      This study will examine how the brain rewires itself to make up for the lack of movement many
      people with stroke experience. It will try to determine if the rewiring differs depending on
      the location of the stroke and the amount of time since the stroke occurred. For some stoke
      patients, weakness may persist, while others recover completely after time. It is not known
      which parts of the brain are involved in the recovery of different types of stroke and if the
      type of stroke affects recovery.

      People 18 years of age and older who have had subacute thromboembolic or hemorrhagic stroke
      more than 3 months before enrolling may participate in this study.

      Participants come to the NIH Clinical Center three times every 2 years for up to 10 years. At
      the first visit, patients have a neurological examination and perform tests of motor
      abilities such as lifting small objects, turning cards, using a spoon, stacking checkers and
      lifting cans during a short period of time as rapidly as possible.

      At the second visit, subjects have structural magnetic resonance imaging (MRI) scans of the
      brain. MRI uses a strong magnetic field and radio waves to obtain images of body organs and
      tissues. The MRI scanner is a metal cylinder surrounded by a strong magnetic field. During
      the scan, the subject lies on a table that can slide in and out of the cylinder, wearing
      earplugs to muffle loud knocking noises associated with the scanning process. Total scan time
      is about 30 minutes

      At the third visit, subjects perform some simple movement tasks during functional MRI (fMRI)
      scans. The procedure is the same as with structural MRI, except that subjects are asked to
      perform simple movement tasks in the scanner. Before the fMRI scans, electrodes are attached
      to the subject's arms and legs to monitor muscle activity (surface electromyography). Total
      scan time is about 1.5 hours. Movement tasks might include pinching a force-measuring
      instrument with the fingers, pressing different keys on a keyboard as fast as possible,
      inserting pegs into small holes on a board, lifting weights, flipping cards or similar
      activities.
    

Detailed description: 
      OBJECTIVES:

      The purpose of this protocol is to acquire information on the types of cortical
      reorganization associated with different stroke lesions. This is important for formulating
      hypotheses on lesion-specific types of cortical plasticity following stroke. Understanding
      lesion-specific cortical reorganization is essential to advancing our understanding of the
      mechanism(s) underlying functional reorganization and recovery after stroke.

      This protocol will establish a neuroimaging database of brain activations in stroke patients
      with various lesion sites using task-controlled functional and high-resolution structural
      magnetic resonance imaging (MRI) methods and detailed monitoring of task performance in the
      scanner (electromyography [EMG] and motor kinematics). Specifically, we propose to acquire
      the following from each new patient in the clinic who has had a stroke at least 3 months
      prior to their visit:

        1. A high-resolution T1-weighted structural scan and T2-weighted MRI; used to characterize
           lesion location and to quantify tissue loss.

        2. A functional magnetic resonance imaging (fMRI) scan with standardized motor tasks.

      Both will be repeated every two years, for up to 10 years to provide preliminary information
      on the consistency of plastic changes over time in the chronic stage. This information will
      be used to generate future hypotheses and power analysis on lesion-specific forms of cortical
      reorganization.

      STUDY POPULATION:

      One hundred and twenty five stroke patients aged 18 or above with motor function impairment.

      DESIGN:

      All stroke patients under this protocol will complete the following evaluations during their
      initial visit: clinical interview and neurological exam, the National Institutes of Health
      Stroke Scale (NIH Stroke Scale), the Medical Research Council (MRC), and Jebsen-Taylor
      scores.

      Following the initial screening, subjects will be asked to participate in up to two MRI
      sessions every two years. Session 1 includes anatomical MRI scans (T1- and T2-weighted);
      Session 2 involves BOLD functional MRI scans.

      OUTCOME MEASURES:

      Outcome measures will include lesion loci and size, gray matter loss (volume size), white
      matter loss (volume size), total white matter volume, total gray matter volume, patterns of
      fMRI BOLD activation within and across sessions, the NIH Stroke scale, the MRC, and
      Jebsen-Taylor test scores.
    

Time perspective: Other
Keywords: Stroke; Rehabilitation; Plasticity; fMRI; Reorganization