Connectivity Analysis for Epileptogenic Focus Localization

The measure of Generalized Partial Directed Coherence (GPDC) and surrogate data analysis of intracranial electroencephalographic (iEEG) signals can be used to determine the functional connections between brain sites. Characteristics of the nodes of the thus derived network during seizures from 9 patients with temporal lobe epilepsy were studied using centrality measures (Degree, Eigenvector, Katz, PageRank, and Betweenness). The electrode sites with maximum Katz and degree centralities showed close association with the epileptogenic focus during seizures. These results indicate that connectivity analysis of the EEG can contribute to the accurate localization of the epileptogenic focus in patients with focal epilepsy.