Structural and Functional Brain Changes in Response to Post-Stroke Rehabilitation

A third of American Veterans is left with moderate to severe motor deficits after stroke.
Intensive rehabilitation can resolve some of these deficits. Motor function restoration is
associated with and dependent on reorganization of neuronal networks (i.e. plasticity).
However, our understanding of human brain plasticity during functional recovery is
incomplete. Furthermore, it is unknown what patterns of structural brain changes are
associated with greater gains in motor function as a result of motor learning therapy. The
main objective of the study is to characterize the reorganization of brain structure and
function that is associated with greater gains in motor function following restorative
rehabilitation for chronic survivors. This will further our understanding of recovery after
brain injury and subsequently assist in more accurately directing rehabilitation therapies
to produce the best possible outcomes.

The two hypotheses are: I. There is reorganization of both movement control brain regions
and pathways between regions that is associated with functional motor recovery in response
to intensive motor learning after stroke; and II. For stroke victims with upper extremity
deficits, motor recovery is associated with changes in the sequential timing of activity
across cortical regions.

Design and Methods. A cohort of chronic stroke survivors with upper extremity deficits will
be treated by our intensive multimodal 12-week motor learning program. Brain imaging
(functional Magnetic Resonance Imaging (fMRI) and Diffusion Tensor Imaging (DTI)) and
neurophysiological (Electroencephalogram (EEG)) studies as well as functional motor tests
(Arm Motor Activity test and Fugl-Meyer Coordination test) will be obtained before and after
the treatment. Age-matched control subjects will be evaluated as well. DTI/fMRI and EEG/fMRI
combination techniques will be used to determine changes in brain structure and function as
a result of the treatments. A regression analysis will determine which brain structure
parameters can predictor greater motor function gains.

Inclusion Criteria for chronic stroke patients:

1. Medically stable and at least 6 months post ischemic stroke.

2. Inability to use upper limb for functional tasks

3. Sufficient endurance to participate in rehabilitation

4. Cognition sufficiently intact to give valid informed consent to participate

5. Ability to follow two stage commands

6. Trace or better contraction of the following muscles: finger flexors, wrist flexors
and extensors, shoulder flexors or abductors, shoulder horizontal abductors, scapular
retractors

7. Muscle tone of fingers, wrist and elbow flexors ≤3 (Ashworth scale)

8. Age > 21

Exclusion Criteria

1. Acute or progressive cardiac, renal, respiratory, neurological disorders or
malignancy

2. Active psychiatric diagnosis or psychological condition

3. Lower motor neuron damage or radiculopathy

4. Hand grasp and release sufficient to grasp 4 oz. can, lift 12 inches, replace it in
original position and release grasp within 1-2 seconds of the time of the unaffected
extremity

5. Absent position sense at elbow or wrist

6. More than one ischemic strokes or stroke affecting both sides

7. Metal implants, pacemaker, claustrophobia, or inability to operate the MRI patient
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