Magnetoencephalography Reveals a Widespread Increase in Network Connectivity in Idiopathic/Genetic Generalized Epilepsy

PLoS One. 2015 Sep 14;10(9):e0138119. doi: 10.1371/journal.pone.0138119. eCollection 2015.

Abstract

Idiopathic/genetic generalized epilepsy (IGE/GGE) is characterized by seizures, which start and rapidly engage widely distributed networks, and result in symptoms such as absences, generalized myoclonic and primary generalized tonic-clonic seizures. Although routine magnetic resonance imaging is apparently normal, many studies have reported structural alterations in IGE/GGE patients using diffusion tensor imaging and voxel-based morphometry. Changes have also been reported in functional networks during generalized spike wave discharges. However, network function in the resting-state without epileptiforme discharges has been less well studied. We hypothesize that resting-state networks are more representative of the underlying pathophysiology and abnormal network synchrony. We studied functional network connectivity derived from whole-brain magnetoencephalography recordings in thirteen IGE/GGE and nineteen healthy controls. Using graph theoretical network analysis, we found a widespread increase in connectivity in patients compared to controls. These changes were most pronounced in the motor network, the mesio-frontal and temporal cortex. We did not, however, find any significant difference between the normalized clustering coefficients, indicating preserved gross network architecture. Our findings suggest that increased resting state connectivity could be an important factor for seizure spread and/or generation in IGE/GGE, and could serve as a biomarker for the disease.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Epilepsy, Generalized / physiopathology*
  • Genetic Diseases, Inborn / physiopathology*
  • Humans
  • Magnetoencephalography*
  • Middle Aged
  • Models, Neurological*
  • Nerve Net / physiopathology*

Grants and funding

AE was supported by the Werner Reichardt Centre for Integrative Neuroscience (URL: http://www.cin.uni-tuebingen.de, Grants: PP 2011-14 and PP 2014-02), and Deutsche Forschungsgemeinschaft (URL: http://www.dfg.de, Grant: CIN EXC 307). The authors acknowledge support by Open Access Publishing Fund of University of Tübingen. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.