Focal cortical dysplasia alters electrophysiological cortical hubs in the resting-state

Objective: To test the hypothesis that epilepsy patients with focal cortical dysplasia (FCD) have different electrophysiological functional cortical hubs from those of healthy controls. Methods: Resting-state functional networks in the theta, alpha, beta and gamma frequency bands were evaluated in 35 epilepsy patients with histopathologically verified FCD as a single pathology and in 46 age-matched healthy controls. Using magnetoencephalography (MEG), we investigated the network differences between the two groups by comparing the nodal efficiency (Enodal) and betweenness centrality (BC) values at the source level. Results: The FCD patients had significant Enodal increases in the functional cortical hubs in the left anterior, middle, and posterior cortices and the medial orbital superior frontal cortex in the beta band. The left posterior cingulate cortex showed significant BC increases in the theta, alpha, and beta bands. There was a negative correlation between Enodal and age at seizure onset. Conclusions: Cortical dysplasia alters whole brain functional cortical hubs compared to healthy controls. The age at seizure onset was negatively correlated with Enodal in the beta band in FCD patients. Significance: Our study for the first time investigated the functional cortical hubs and their alteration in the resting-state functional network in epilepsy patients with FCD using noninvasive MEG signals. (c) 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.