Adaptive and Maladaptive Brain Functional Network Reorganization After Stroke in Hemianopia Patients: An...

Area of Science:

• Neuroscience
• Neurophysiology
• Systems Neuroscience

Background:

• Occipital stroke often leads to hemianopia, traditionally attributed to local damage.
• Functional connectivity network (FCN) reorganization in distant brain regions is observed, but its adaptive or maladaptive nature remains unclear.

Purpose of the Study:

• To investigate local and global brain plasticity after occipital stroke.
• To characterize FCN reorganization using electrophysiology.
• To correlate FCN changes with visual performance.

Main Methods:

• Resting-state electroencephalography (EEG) was recorded in chronic stroke patients and controls.
• Imaginary part of coherence was calculated to assess FCNs.
• Graph theory metrics were correlated with visual detection and reaction time.

Main Results:

• Stroke brains exhibited altered FCNs in alpha and low beta bands in occipital and temporal regions.
• Global FCN organization was less efficient.
• Local reorganization showed increased rigidity in the occipital network and increased efficiency in the temporal network, correlating with visual performance.

Conclusions:

• Occipital stroke induces both local and global FCN reorganization, which can be adaptive or maladaptive.
• A more regular FCN structure in the intact visual cortex may represent maladaptive plasticity, contributing to perceptual deficits.
• Reorganization in temporal regions appears adaptive, potentially enhancing peripheral movement perception.