title: Dynamics of regional brain activity in epilepsy: a cross-disciplinary study on both intracranial and scalp-recorded epileptic seizures.
abstract: OBJECTIVE
  Recent cross-disciplinary literature suggests a dynamical analogy between earthquakes and epileptic seizures. This study extends the focus of inquiry for the applicability of models for earthquake dynamics to examine both scalp-recorded and intracranial electroencephalogram recordings related to epileptic seizures.
  
  
  METHODS
  First, we provide an updated definition of the electric event in terms of magnitude and we focus on the applicability of (i) a model for earthquake dynamics, rooted in a nonextensive Tsallis framework, (ii) the traditional Gutenberg and Richter law and (iii) an alternative method for the magnitude-frequency relation for earthquakes. Second, we apply spatiotemporal analysis in terms of nonextensive statistical physics and we further examine the behavior of the parameters included in the nonextensive formula for both types of electroencephalogram recordings under study.
  
  
  RESULTS
  We confirm the previously observed power-law distribution, showing that the nonextensive formula can adequately describe the sequences of electric events included in both types of electroencephalogram recordings. We also show the intermittent behavior of the epileptic seizure cycle which is analogous to the earthquake cycles and we provide evidence of self-affinity of the regional electroencephalogram epileptic seizure activity.
  
  
  CONCLUSIONS
  This study may provide a framework for the analysis and interpretation of epileptic brain activity and other biological phenomena with similar underlying dynamical mechanisms.
authors.affiliation: Department of Electronic and Computer Engineering, Brunel University Uxbridge, Middlesex, UB8 3PH, UK.
authors.forename: George
authors.initials: G
authors.lastname: Minadakis
authors.forename: Errikos
authors.initials: E
authors.lastname: Ventouras
authors.forename: Stylianos D
authors.initials: SD
authors.lastname: Gatzonis
authors.forename: Anna
authors.initials: A
authors.lastname: Siatouni
authors.forename: Hara
authors.initials: H
authors.lastname: Tsekou
authors.forename: Ioannis
authors.initials: I
authors.lastname: Kalatzis
authors.forename: Damianos E
authors.initials: DE
authors.lastname: Sakas
authors.forename: John
authors.initials: J
authors.lastname: Stonham
mesh_terms: D001921:Brain / Q000502:physiology*; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000295:instrumentation / Q000379:methods*; D004827:Epilepsy / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D012535:Scalp / Q000502:physiology*; D012640:Seizures / Q000175:diagnosis / Q000503:physiopathology