Whole-brain functional connectivity increases with extended duration of focal epileptiform activity

The analysis of interictal epileptiform discharges (IEDs) using magnetoencephalography (MEG) is utilized for the localization of seizure onset zones in the presurgical planning of epilepsy patients. Additionally, resting-state functional connectivity analyses using the IED area may provide novel insight into the underlying brain networks. In this study, we evaluate whether chronicity of seizures is related to whole-brain functional connectivity metrics using the area of IED generation (derived from MEG) as the seed region. We found a positive correlation between the duration of seizures and beta-band functional connectivity between the epileptogenic zone and other brain areas. This suggests the presence of inhibitory GABAergic modulation of distal brain regions in response to chronic epileptiform activity.