title: Epilepsy surgery failure in children: a quantitative and qualitative analysis.
abstract: OBJECTIVE
  Resection is a safe and effective treatment option for children with pharmacoresistant focal epilepsy, but some patients continue experience seizures after surgery. While most studies of pediatric epilepsy surgery focus on predictors of postoperative seizure outcome, these factors are often not modifiable, and the reasons for surgical failure may remain unclear.
  
  
  METHODS
  The authors performed a retrospective cohort study of children and adolescents who received focal resective surgery for pharmacoresistant epilepsy. Both quantitative and qualitative analyses of factors associated with persistent postoperative seizures were conducted.
  
  
  RESULTS
  Records were reviewed from 110 patients, ranging in age from 6 months to 19 years at the time of surgery, who underwent a total of 115 resections. At a mean 3.1-year follow-up, 76% of patients were free of disabling seizures (Engel Class I outcome). Seizure freedom was predicted by temporal lobe surgery compared with extratemporal resection, tumor or mesial temporal sclerosis compared with cortical dysplasia or other pathologies, and by a lower preoperative seizure frequency. Factors associated with persistent seizures (Engel Class II-IV outcome) included residual epileptogenic tissue adjacent to the resection cavity (40%), an additional epileptogenic zone distant from the resection cavity (32%), and the presence of a hemispheric epilepsy syndrome (28%).
  
  
  CONCLUSIONS
  While seizure outcomes in pediatric epilepsy surgery may be improved by the use of high-resolution neuroimaging and invasive electrographic studies, a more aggressive resection should be considered in certain patients, including hemispherectomy if a hemispheric epilepsy syndrome is suspected. Family counseling regarding treatment expectations is critical, and reoperation may be warranted in select cases.
authors.affiliation: UCSF Comprehensive Epilepsy Center and 
authors.forename: Dario J
authors.initials: DJ
authors.lastname: Englot
authors.forename: Seunggu J
authors.initials: SJ
authors.lastname: Han
authors.forename: John D
authors.initials: JD
authors.lastname: Rolston
authors.forename: Michael E
authors.initials: ME
authors.lastname: Ivan
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Kuperman
authors.forename: Edward F
authors.initials: EF
authors.lastname: Chang
authors.forename: Nalin
authors.initials: N
authors.lastname: Gupta
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Sullivan
authors.forename: Kurtis I
authors.initials: KI
authors.lastname: Auguste
mesh_terms: D000293:Adolescent; D000927:Anticonvulsants / Q000008:administration & dosage; D002648:Child; D002675:Child, Preschool; D004351:Drug Resistance; D004569:Electroencephalography; D004827:Epilepsy / Q000175:diagnosis / Q000188:drug therapy / Q000601:surgery*; D004833:Epilepsy, Temporal Lobe / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D053208:Kaplan-Meier Estimate; D008297:Male; D059906:Neuroimaging; D019635:Neurosurgical Procedures / Q000379:methods*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D012640:Seizures / Q000517:prevention & control*; D013702:Temporal Lobe / Q000601:surgery*; D017211:Treatment Failure; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000927:Anticonvulsants
keywords: CHRCO = Children's Hospital and Research Center Oakland; ECoG = electrocorticography; EEG = electroencephalography; FCD = focal cortical dysplasia; MCD = malformation of cortical development; MTS = mesial temporal sclerosis; TLE = temporal lobe epilepsy; UCSF = University of California, San Francisco; epilepsy surgery; focal cortical dysplasia; mesial temporal sclerosis; recurrence; seizure outcome