title: Clinical factors predict surgical outcomes in pediatric MRI-negative drug-resistant epilepsy.
abstract: OBJECTIVE
  Lack of a potentially epileptogenic lesion on brain magnetic resonance imaging (MRI) is a poor prognostic marker for epilepsy surgery. We present a single-center series of childhood-onset MRI-negative drug-resistant epilepsy (DRE) and analyze surgical outcomes and predictors.
  
  
  METHODS
  Children with MRI-negative DRE who had resective surgery from January 2007 to December 2013 were identified using an institutional database. Relevant clinical, neurophysiological, imaging, and surgical data was extracted. The primary outcome measure was seizure freedom. Predictors of seizure freedom were obtained using multivariate logistic regression.
  
  
  RESULTS
  Out of 47 children with MRI-negative DRE, 12 (25.5%) were seizure free (International League Against Epilepsy [ILAE] outcome class I), after mean follow-up of 2.75 (±1.72) years. Seizure-free proportion was significantly higher in patients with single seizure semiology and concordant ictal EEG (50.0% vs. 15.2%, p=0.025). Multivariate analysis using only non-invasive pre-surgical data showed that children with daily seizures (OR 0.02, 95% CI<0.001-0.55), and earlier onset of seizures (OR 0.72, 95% CI 0.52-0.99) were less likely to be seizure-free. Also, each additional anti-epileptic drug (AED) tried before surgery decreased the probability of seizure-free outcome (OR 0.16, 95% CI 0.04-0.63). Repeat multivariate analysis after including surgical variables found no additional significant predictors of seizure-freedom. Cortical dysplasia (ILAE type IB) was the commonest histopathology.
  
  
  CONCLUSIONS
  Surgical outcomes in children with MRI-negative DRE are determined by clinical factors including seizure frequency, age of onset of seizures, and number of failed AEDs.
authors.affiliation: Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA. Electronic address: Ravindra.Arya@cchmc.org.
authors.forename: Ravindra
authors.initials: R
authors.lastname: Arya
authors.affiliation: Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: James L
authors.initials: JL
authors.lastname: Leach
authors.affiliation: Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Division of Epidemiology and Biostatistics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Horn
authors.affiliation: Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Hansel M
authors.initials: HM
authors.lastname: Greiner
authors.affiliation: Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Gelfand
authors.affiliation: Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Anna W
authors.initials: AW
authors.lastname: Byars
authors.affiliation: Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Todd M
authors.initials: TM
authors.lastname: Arthur
authors.affiliation: Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Tenney
authors.affiliation: Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Sejal V
authors.initials: SV
authors.lastname: Jain
authors.affiliation: Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Leonid
authors.initials: L
authors.lastname: Rozhkov
authors.affiliation: Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Hisako
authors.initials: H
authors.lastname: Fujiwara
authors.affiliation: Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Douglas F
authors.initials: DF
authors.lastname: Rose
authors.affiliation: Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Francesco T
authors.initials: FT
authors.lastname: Mangano
authors.affiliation: Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
authors.forename: Katherine D
authors.initials: KD
authors.lastname: Holland
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D000069279:Drug Resistant Epilepsy / Q000000981:diagnostic imaging* / Q000601:surgery*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D016015:Logistic Models; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D009493:Neurosurgery / Q000379:methods*; D017063:Outcome Assessment, Health Care; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: Childhood epilepsy; Drug-resistant epilepsy; Epilepsy surgery; MRI negative epilepsy; Outcomes