Assortative mixing in functional brain networks during epileptic seizures

Area of Science:

• Neuroscience
• Epilepsy Research
• Network Science

Background:

• Epileptic seizures involve complex brain network dynamics.
• Understanding seizure generation, propagation, and termination is crucial for epilepsy treatment.
• Previous studies noted changes in global statistical properties and synchronizability during seizures.

Purpose of the Study:

• To investigate the assortativity of functional brain networks before, during, and after epileptic seizures.
• To determine if assortativity is inherent to seizure dynamics and how it evolves over time.
• To explore the relationship between network segregation and seizure termination.

Main Methods:

• Construction of binary functional brain networks from multi-channel electroencephalographic (EEG) data.
• Analysis of time-resolved estimates of the assortativity coefficient.
• Inclusion of data from 60 epilepsy patients across 100 seizures with varying anatomical onset locations.

Main Results:

• Positive degree-degree correlations, indicating assortativity, are inherent to epileptic seizure dynamics.
• Assortativity increases as seizures evolve, suggesting functional network segregation into sparsely interconnected brain regions.
• A decrease in assortativity is observed prior to seizure termination.

Conclusions:

• Assortativity is a key characteristic of functional brain network dynamics during epileptic seizures.
• Network segregation plays a role in seizure evolution and termination.
• These findings contribute to a deeper understanding of the complex mechanisms underlying epileptic seizures.