Motor practice promotes increased activity in brain regions structurally disconnected after subcortical stroke

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Neuroimaging

Background:

• Motor practice is crucial for neurorehabilitation.
• Brain activation patterns change with practice in healthy individuals.
• Understanding functional brain plasticity post-stroke can inform rehabilitation strategies.

Purpose of the Study:

• To determine if practice-related brain activity changes differ between stroke survivors and healthy controls.
• To investigate the relationship between brain activity changes and structural damage patterns.

Main Methods:

• 10 subcortical stroke patients and 18 healthy controls underwent diffusion-weighted and functional MRI (fMRI).
• fMRI was performed during a visuomotor tracking task before and after 15 days of practice.
• Structural integrity was assessed using fractional anisotropy.

Main Results:

• Lower fractional anisotropy in the posterior limbs of the internal capsule correlated with smaller practice effects in patients.
• A significant Group × Time interaction was observed in the basal ganglia, thalamus, inferior frontal gyrus, superior temporal gyrus, and insula.
• Healthy controls showed decreased activity with practice, while stroke patients showed increased activity in these regions.

Conclusions:

• Performance gains in motor tasks post-stroke can be linked to increased activity in impaired or indirectly affected brain regions.
• Neurorehabilitation may involve compensatory adaptations in intact brain areas and enhanced activity in structurally compromised regions.