Connectivity Measures Differentiate Cortical and Subcortical Sub-Acute Ischemic Stroke Patients

Area of Science:

• Neuroscience
• Neurology
• Biomedical Engineering

Background:

• Cerebral ischemia causes brain lesions, leading to widespread network disturbances and altered functional connectivity.
• Quantitative electroencephalography (qEEG) is used to study post-stroke brain activity and connectivity, but results are often inconsistent.
• Understanding how lesion location influences these changes is crucial for interpreting findings and predicting outcomes.

Purpose of the Study:

• To investigate how brain activity and functional connectivity change after stroke, considering lesion location.
• To explore the relationship between EEG measures, lesion type, and functional recovery.
• To identify potential biomarkers for predicting spontaneous recovery in stroke patients.

Main Methods:

• Utilized basic and advanced electroencephalography (EEG) methods to analyze resting-state EEG data.
• Recruited 33 sub-acute stroke patients (cortico-subcortical and subcortical groups) and 10 healthy controls.
• Assessed neurophysiological (EEG) and clinical (Barthel Index) measures longitudinally from 45 days to 3 months post-stroke.

Main Results:

• Theta-band power normalized over time in the cortico-subcortical group but not the subcortical group.
• Significant differences in beta-band connectivity and network measures (Integration, Segregation, Small-worldness) were observed between patient groups at baseline.
• Baseline connectivity measures showed a group-dependent predictive role for functional recovery.

Conclusions:

• Brain connectivity patterns and their correlation with recovery after stroke are significantly influenced by lesion location.
• These findings may explain the heterogeneity in previous stroke EEG studies and offer potential biomarkers for recovery prediction.
• EEG-based network measures could aid in selecting homogenous patient groups for future clinical trials.