| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 3052242 | Epilepsy Research | 2013 | 13 Pages |
•The “network concept” of epilepsy is applicable to juvenile myoclonic epilepsy (JME).•Interictal EEG background activity in JME shows abnormal network characteristics.•Abnormally increased connectivity (hypercoupling) is maximal among cortical areas that subserve motor functions and sensory-motor integration.•The baseline network abnormality is further amplificated in the immediate preictal state.
SummaryIntroductionThe neuronal mechanisms of enduring seizure propensity and seizure precipitation in juvenile myoclonic epilepsy (JME) are not known. We investigated these issues, within the framework of the “network concept” of epilepsy.MethodsDesign1: 19, unmedicated JME patients were compared with nineteen, age-, and sex-matched normal control persons (NC). A total of 120 s, artifact-free, paroxysm-free, eyes-closed, resting state EEG background activity was analyzed for each person. Design2: interictal and immediate preictal periods of the JME patients were compared in order to explore interictal–preictal network differences. For both comparison designs, statistically significant differences of EEG functional connectivity (EEGfC), nodal and global graph parameters were evaluated.Main resultsDesign1: maximum abnormalities were: increased delta, theta, alpha1 EEGfC and decreased alpha2 and beta EEGfC in the JME group as compared to the NC group, mainly among cortical areas that are involved in sensory-motor integration. Nodal degree and efficiency of three, medial, basal frontal nodes were greater in JME than in NC, in the alpha1 band. Design2: preictal delta EEGfC showed further increase in the above-mentioned areas, as compared to the interictal state.DiscussionIncreased EEGfC indicates a hypercoupled state among the specified cortical areas. This interictal abnormality further increases in the preictal state. Nodal graph statistics indicates abnormal neuronal dynamics in the cortical area that is the ictal onset zone in JME.SignificanceInterictal and preictal neuronal dysfunction has been described in terms of network dynamics and topography in JME patients. Forthcoming investigations of seizure precipitation and therapeutic drug effects are encouraged on this basis.
