title: Neurophysiology of juvenile myoclonic epilepsy: EEG-based network and graph analysis of the interictal and immediate preictal states.
abstract: BACKGROUND
  The 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.
  
  
  METHODS
  Design1: 19, unmedicated JME patients were compared with nineteen, age-, and sex-matched normal control persons (NC). A total of 120s, 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.
  
  
  RESULTS
  Design1: 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.
  
  
  CONCLUSIONS
  Increased 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.
  
  
  CONCLUSIONS
  Interictal 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.
authors.affiliation: Kenézy Hospital Ltd., Department of Neurology, Debrecen, Hungary.
authors.forename: B
authors.initials: B
authors.lastname: Clemens
authors.forename: S
authors.initials: S
authors.lastname: Puskás
authors.forename: M
authors.initials: M
authors.lastname: Besenyei
authors.forename: T
authors.initials: T
authors.lastname: Spisák
authors.forename: G
authors.initials: G
authors.lastname: Opposits
authors.forename: K
authors.initials: K
authors.lastname: Hollódy
authors.forename: A
authors.initials: A
authors.lastname: Fogarasi
authors.forename: I
authors.initials: I
authors.lastname: Fekete
authors.forename: M
authors.initials: M
authors.lastname: Emri
mesh_terms: D000293:Adolescent; D000465:Algorithms; D000513:Alpha Rhythm / Q000502:physiology; D002540:Cerebral Cortex / Q000503:physiopathology; D002648:Child; D003627:Data Interpretation, Statistical; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D020190:Myoclonic Epilepsy, Juvenile / Q000503:physiopathology*; D009415:Nerve Net / Q000503:physiopathology; D012640:Seizures / Q000503:physiopathology*; D013826:Theta Rhythm / Q000502:physiology; D055815:Young Adult
keywords: E(g); E(l); EEG; EEG functional connectivity; EEGfC; FDR; Functional connectivity; GMSW; Graph analysis; IGE; JME; Juvenile myoclonic epilepsy; LORETA; LORETA source correlation; LSC; NC; Network; ROI; SPN; false detection rate; generalized spike-wave (paroxysm); global efficiency; idiopathic generalized epilepsy; ii; interictal; juvenile myoclonic epilepsy; local efficiency; low resolution electromagnetic tomography; normal (healthy) control; pi; preictal; region of interest; statistical parametric network