Dynamic functional reorganization of the motor execution network after stroke

Area of Science:

• Neuroscience
• Neurology
• Systems Neuroscience

Background:

• Cortical reorganization is believed to aid motor function recovery post-stroke.
• The temporal dynamics of these brain changes during recovery remain understudied.

Purpose of the Study:

• To investigate dynamic changes in the topological characteristics of the motor execution network during stroke recovery.
• To understand the evolution of functional organization during the post-stroke period.

Main Methods:

• Resting-state functional magnetic resonance imaging (fMRI) was used in 10 subcortical stroke patients over five time points within a year.
• Motor execution networks were analyzed using graph theory and functional connectivity matrices.
• Mixed-effects models evaluated dynamic topological changes over time.

Main Results:

• The motor execution network transitioned towards a more random configuration during recovery, suggesting less optimized reorganization.
• Increased regional centrality was observed in the ipsilesional primary motor cortex and contralesional cerebellum.
• Decreased centrality in the ipsilesional cerebellum and altered functional connectivity were noted, correlating with clinical variables.

Conclusions:

• Stroke recovery involves dynamic alterations in the motor execution network's topology.
• These findings suggest a less optimized but adaptive reorganization process contributing to motor function restoration.
• The study provides insights into lesion-induced network plasticity and offers a framework for future research.