title: Millimeter-scale epileptiform spike propagation patterns and their relationship to seizures.
abstract: OBJECTIVE
  Current mapping of epileptic networks in patients prior to epilepsy surgery utilizes electrode arrays with sparse spatial sampling (∼1.0 cm inter-electrode spacing). Recent research demonstrates that sub-millimeter, cortical-column-scale domains have a role in seizure generation that may be clinically significant. We use high-resolution, active, flexible surface electrode arrays with 500 μm inter-electrode spacing to explore epileptiform local field potential (LFP) spike propagation patterns in two dimensions recorded from subdural micro-electrocorticographic signals in vivo in cat. In this study, we aimed to develop methods to quantitatively characterize the spatiotemporal dynamics of epileptiform activity at high-resolution.
  
  
  METHODS
  We topically administered a GABA-antagonist, picrotoxin, to induce acute neocortical epileptiform activity leading up to discrete electrographic seizures. We extracted features from LFP spikes to characterize spatiotemporal patterns in these events. We then tested the hypothesis that two-dimensional spike patterns during seizures were different from those between seizures.
  
  
  RESULTS
  We showed that spatially correlated events can be used to distinguish ictal versus interictal spikes.
  
  
  CONCLUSIONS
  We conclude that sub-millimeter-scale spatiotemporal spike patterns reveal network dynamics that are invisible to standard clinical recordings and contain information related to seizure-state.
authors: Department of Electrical and Computer Engineering, United States Naval Academy, Annapolis, MD, USA.
authors: Ann C
authors: AC
authors: Vanleer
authors: Justin A
authors: JA
authors: Blanco
authors: Joost B
authors: JB
authors: Wagenaar
authors: Jonathan
authors: J
authors: Viventi
authors: Diego
authors: D
authors: Contreras
authors: Brian
authors: B
authors: Litt
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D002415:Cats; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000379:methods*; D012640:Seizures / Q000503:physiopathology*