title: Pre-seizure architecture of the local connections of the epileptic focus examined via graph-theory.
abstract: Epilepsy is characterized by unpredictable and sudden paroxysmal neuronal firing occurrences and sometimes evolving in clinically evident seizure. To predict seizure event, small-world characteristic in nine minutes before seizure, divided in three 3-min periods (T0, T1, T2) were investigated.
  
  
  
  Intracerebral recordings were obtained from 10 patients with drug resistant focal epilepsy examined by means of stereotactically implanted electrodes; analysis was focused in a period of low spiking (Baseline) and during two seizures. Networks' architecture is undirected and weighted. Electrodes' contacts close to epileptic focus are the vertices, edges are weighted by mscohere (=magnitude squared coherence).
  
  
  
  Differences were observed between Baseline and T1 and between Baseline and T2 in theta band; and between Baseline and T1, Baseline and T2, and near-significant difference between T0 and T2 in Alpha 2 band. Moreover, an intra-band index was computed for small worldness as difference between Theta and Alpha 2. It was found a growing index trend from Baseline to T2.
  
  
  
  Cortical network features a specific pre-seizure architecture which could predict the incoming epileptic seizure.
  
  
  
  Through this study future researches could investigate brain connectivity modifications approximating a clinical seizure also in order to address a preventive therapy.
authors.affiliation: Brain Connectivity Laboratory, IRCCS San Raffaele Pisana, Rome, Italy. Electronic address: fabrizio.vecchio@uniroma1.it.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Vecchio
authors.affiliation: Brain Connectivity Laboratory, IRCCS San Raffaele Pisana, Rome, Italy; Institute of Neurology, Dept. Geriatrics, Neuroscience & Orthopedics, Catholic University, Policlinico A. Gemelli, Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Miraglia
authors.affiliation: Institute of Neurology, Dept. Geriatrics, Neuroscience & Orthopedics, Catholic University, Policlinico A. Gemelli, Rome, Italy.
authors.forename: Catello
authors.initials: C
authors.lastname: Vollono
authors.affiliation: Institute of Neurosurgery, Dept Surgery of Head and Neck, Catholic University, Rome, Italy.
authors.forename: Filomena
authors.initials: F
authors.lastname: Fuggetta
authors.affiliation: IRCCS Centro Neurolesi Bonino-Pulejo, Messina, Italy.
authors.forename: Placido
authors.initials: P
authors.lastname: Bramanti
authors.affiliation: Institute of Neurosurgery, Dept Surgery of Head and Neck, Catholic University, Rome, Italy.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Cioni
authors.affiliation: Brain Connectivity Laboratory, IRCCS San Raffaele Pisana, Rome, Italy; Institute of Neurology, Dept. Geriatrics, Neuroscience & Orthopedics, Catholic University, Policlinico A. Gemelli, Rome, Italy.
authors.forename: Paolo Maria
authors.initials: PM
authors.lastname: Rossini
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology; D063132:Connectome; D000069279:Drug Resistant Epilepsy / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D013826:Theta Rhythm
keywords: Epilepsy; Functional connectivity; Graph theory; Seizure; Small-world; eLORETA; sEEG