title: Preresection intraoperative electrocorticography (ECoG) abnormalities predict seizure-onset zone and outcome in pediatric epilepsy surgery.
abstract: OBJECTIVE
  The predictive value of intraoperative electrocorticography (ECoG) in pediatric epilepsy surgery is unknown. In a population of children undergoing ECoG followed typically by invasive extraoperative monitoring (IEM) and resection, we aimed to determine the relationship between frequent ECoG abnormalities and the seizure onset zone and outcome after resection.
  
  
  METHODS
  We retrospectively identified 103 children with preresection ECoG of sufficient technical quality. ECoG records were scored based on electrode location and frequency, blinded to the seizure-onset zone and outcome. Electrographic seizure and spike locations were identified. Locations of seizures and spike populations were then compared to the location of seizure-onset zone defined by IEM using subdural electrodes and resection margin.
  
  
  RESULTS
  Electrographic seizures were identified in 11 (11%) of 103 patients. A spike population of one or more was noted in 79 (77%) of 103 patients. In 50 (63%) of 79 patients, spike populations correlated with seizure-onset zone location. The overall surgical outcome was good (ILAE 1 to 3) in 53 (52%) of 101 patients. Outcome was good in seven (78%) of nine patients when electrographic seizure location was resected. The best outcomes were obtained with resection of both the seizure-onset zone and ECoG abnormalities to include seizures and spike locations (22/33 good outcome, 67%, p = 0.008). There was a significantly better outcome in children with complete resection of ECoG-identified spike populations (14/26, 62% good outcome) compared to when none were resected (4/14, 29%, p = 0.043).
  
  
  CONCLUSIONS
  Electrographic seizures and frequent spikes are frequently seen on pre-resection ECoG in children. The brain locations corresponding to these discharges are highly concordant with the seizure-onset zone; resection of these regions is correlated with good seizure outcome. Further research is needed to design interventions that increase the reliability of ECoG prediction of the epileptogenic zone and obviate the need for IEM.
authors.affiliation: Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A.
authors.forename: Hansel M
authors.initials: HM
authors.lastname: Greiner
authors.affiliation: Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Horn
authors.affiliation: Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Tenney
authors.affiliation: Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A.
authors.forename: Ravindra
authors.initials: R
authors.lastname: Arya
authors.affiliation: Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A.
authors.forename: Sejal V
authors.initials: SV
authors.lastname: Jain
authors.affiliation: Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A.
authors.forename: Katherine D
authors.initials: KD
authors.lastname: Holland
authors.affiliation: Division of Neuroradiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A.
authors.forename: James L
authors.initials: JL
authors.lastname: Leach
authors.affiliation: Division of Pathology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A.
authors.forename: Lili
authors.initials: L
authors.lastname: Miles
authors.affiliation: Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A.
authors.forename: Douglas F
authors.initials: DF
authors.lastname: Rose
authors.affiliation: Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A.
authors.forename: Hisako
authors.initials: H
authors.lastname: Fujiwara
authors.affiliation: Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, U.S.A.
authors.forename: Francesco T
authors.initials: FT
authors.lastname: Mangano
mesh_terms: D000293:Adolescent; D002648:Child; D000069280:Electrocorticography / Q000379:methods*; D004567:Electrodes, Implanted; D004827:Epilepsy / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D016343:Monitoring, Intraoperative / Q000379:methods*; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods; D012189:Retrospective Studies; D012640:Seizures / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome
keywords: ECoG; Electrocorticography; Invasive EEG; Nonlesional