Article

Motor practice is an important component of neurorehabilitation.
Imaging studies in healthy individuals show that dynamic brain activation changes
with practice. Defining patterns of functional brain plasticity associated with
motor practice following stroke could guide rehabilitation. The
authors aimed to test whether practice-related changes in brain activity differ
after stroke and to explore spatial relationships between activity changes and
patterns of structural degeneration. They studied 10 patients at least 6
months after left-hemisphere subcortical strokes and 18 healthy controls.
Diffusion-weighted magnetic resonance imaging (MRI) was acquired at baseline, and
functional MRI (fMRI) was acquired during performance of a visuomotor tracking
task before and after a 15-day period of practice of the same task. RESULTS:
Smaller short-term practice effects at baseline correlated with lower fractional
anisotropy in the posterior limbs of the internal capsule (PLIC) bilaterally in
patients (t > 3; cluster P < .05). After 15 days of motor practice a Group x Time
interaction (z > 2.3; cluster P < .05) was found in the basal ganglia, thalamus,
inferior frontal gyrus, superior temporal gyrus, and insula. In these regions,
healthy controls showed decreases and patients showed increases in activity with
practice. Some regions of interest had a loss of white matter connectivity at
baseline. CONCLUSIONS: Performance gains with motor practice can be associated
with increased activity in regions that have been either directly or indirectly
impaired by loss of connectivity. These results suggest that neurorehabilitation
interventions may be associated with compensatory adaptation of intact brain
regions as well as enhanced activity in regions with impaired structural
connectivity.

Langue : ANGLAIS