title: Localization of ictal onset zones in Lennox-Gastaut syndrome using directional connectivity analysis of intracranial electroencephalography.
abstract: BACKGROUND
  Neuroscientists are becoming interested in the application of computational EEG analysis to the identification of ictal onset zones; however, most studies have focused on the localization of ictal onset zones in focal epilepsy. The present study aimed to estimate the ictal onset zone of Lennox-Gastaut syndrome (LGS) with bilaterally synchronous epileptiform discharges from intracranial electroencephalography (iEEG) recordings using directional connectivity analysis.
  
  
  METHODS
  We analyzed ictal iEEG data acquired from three LGS patients who underwent epileptic surgery with favorable surgical outcomes. To identify the ictal onset zones, we estimated the functional directional connectivity network among the intracerebral electrodes using the directed transfer function (DTF) method.
  
  
  RESULTS
  The analysis results demonstrated that areas with high average outflow values corresponded well with the surgical resection areas identified using electrophysiologic data and conventional neuroimaging modalities.
  
  
  CONCLUSIONS
  Our results suggest that the DTF analysis can be a useful auxiliary tool for determining surgical resection areas prior to epilepsy surgery in LGS patients. This is the first research article demonstrating that directional connectivity analysis of iEEG recording data can be used for delineating surgical resection areas in generalized epilepsy patients who need surgical treatment.
authors.affiliation: Department of Biomedical Engineering, Yonsei University, Wonju, Kangwon-do, Republic of Korea.
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Jung
authors.forename: Hoon-Chul
authors.initials: HC
authors.lastname: Kang
authors.forename: Keom-Ok
authors.initials: KO
authors.lastname: Choi
authors.forename: Joon Soo
authors.initials: JS
authors.lastname: Lee
authors.forename: Dong-Seok
authors.initials: DS
authors.lastname: Kim
authors.forename: Jae-Hyun
authors.initials: JH
authors.lastname: Cho
authors.forename: Shin-Hye
authors.initials: SH
authors.lastname: Kim
authors.forename: Chang-Hwan
authors.initials: CH
authors.lastname: Im
authors.forename: Heung Dong
authors.initials: HD
authors.lastname: Kim
mesh_terms: D000465:Algorithms; D002675:Child, Preschool; D003627:Data Interpretation, Statistical; D004351:Drug Resistance; D004567:Electrodes, Implanted; D004569:Electroencephalography; D005583:Fourier Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008607:Intellectual Disability / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D007361:Intelligence Tests; D065768:Lennox Gastaut Syndrome; D008279:Magnetic Resonance Imaging; D008297:Male; D019635:Neurosurgical Procedures; D049268:Positron-Emission Tomography; D012640:Seizures / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D013036:Spasms, Infantile / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome