Longitudinal changes in functional connectivity networks in the first year following stroke

Area of Science:

• Neuroscience
• Brain Imaging
• Neuroplasticity

Background:

• Brain functional organization involves modular subsystems with inter-hemispheric communication.
• Stroke causes neuroplastic changes, but longitudinal human studies are scarce.
• Understanding post-stroke brain dynamics is crucial for recovery.

Purpose of the Study:

• To investigate longitudinal changes in brain functional organization after stroke.
• To analyze neuroplasticity using resting-state functional MRI connectivity measures.
• To compare stroke survivors to healthy controls over 12 months.

Main Methods:

• Analyzed modularity, hemispheric symmetry, and homotopic connectivity.
• Used resting-state functional MRI in 17 stroke survivors at 1, 3, and 12 months post-stroke.
• Compared data to 13 age-matched healthy controls.

Main Results:

• Modularity decreased over 12 months, indicating less organized brain networks.
• Hemispheric symmetry initially decreased then recovered towards control levels.
• Homotopic connectivity showed a U-shaped recovery, decreasing then increasing over time.

Conclusions:

• Brain reorganization post-stroke is complex and dynamic.
• Different connectivity measures show distinct recovery trajectories.
• Findings highlight the brain's adaptive capacity following injury.