Functional brain network alterations in epilepsy: A magnetoencephalography study

To test the hypotheses that brain networks of patients with epilepsy differ from that of healthy controls and functional interactions in the brain are correlated to the duration of epilepsy.

The present study recorded Magnetoencephalography (MEG) data from twenty patients with epilepsy and twenty healthy controls, constructed the whole functional brain network based on phase lag index (PLI), compared the differences in functional connectivity and network measures between patients with epilepsy and healthy controls, and analyzed the correlation between network measures and the duration of epilepsy.

The patients with epilepsy showed significant increase in mean functional connectivity in the alpha band, gamma band and ripple band, significant increase in mean clustering coefficient in the theta band, beta band and ripple band, significant increase in average shortest path length in the theta band and alpha band. Only in the alpha band, a significant negative correlation between mean clustering coefficient and the duration of epilepsy was detected.

Our results indicated that the alterations of functional brain network are related to a functional imbalance that resulted from epileptic activity and the brain network of patients with epilepsy become more pathological over time.