title: Tumor location and IDH1 mutation may predict intraoperative seizures during awake craniotomy.
abstract: OBJECTIVE
  Intraoperative seizures during awake craniotomy may interfere with patients' ability to cooperate throughout the procedure, and it may affect their outcome. The authors have assessed the occurrence of intraoperative seizures during awake craniotomy in regard to tumor location and the isocitrate dehydrogenase 1 (IDH1) status of the tumor.
  
  
  METHODS
  Data were collected in 137 consecutive patients who underwent awake craniotomy for removal of a brain tumor. The authors performed a retrospective analysis of the incidence of seizures based on the tumor location and its IDH1 mutation status, and then compared the groups for clinical variables and surgical outcome parameters.
  
  
  RESULTS
  Tumor location was strongly associated with the occurrence of intraoperative seizures. Eleven patients (73%) with tumor located in the supplementary motor area (SMA) experienced intraoperative seizures, compared with 17 (13.9%) with tumors in the other three non-SMA brain regions (p < 0.0001). Interestingly, there was no significant association between history of seizures and tumor location (p = 0.44). Most of the patients (63.6%) with tumor in the SMA region harbored an IDH1 mutation compared with those who had tumors in non-SMA regions. Thirty-one of 52 patients (60%) with a preoperative history of seizures had an IDH1 mutation (p = 0.02), and 15 of 22 patients (68.2%) who experienced intraoperative seizures had an IDH1 mutation (p = 0.03). In a multivariate analysis, tumor location was found as a significant predictor of intraoperative seizures (p = 0.002), and a trend toward IDH1 mutation as such a predictor was found as well (p = 0.06). Intraoperative seizures were not associated with worse outcome.
  
  
  CONCLUSIONS
  Patients with tumors located in the SMA are more prone to develop intraoperative seizures during awake craniotomy compared with patients who have a tumor in non-SMA frontal areas and other brain regions. The IDH1 mutation was more common in SMA region tumors compared with other brain regions, and may be an additional risk factor for the occurrence of intraoperative seizures.
authors.affiliation: Department of Neurosurgery.
authors.forename: Tal
authors.initials: T
authors.lastname: Gonen
authors.forename: Rachel
authors.initials: R
authors.lastname: Grossman
authors.forename: Razi
authors.initials: R
authors.lastname: Sitt
authors.forename: Erez
authors.initials: E
authors.lastname: Nossek
authors.forename: Raneen
authors.initials: R
authors.lastname: Yanaki
authors.forename: Emanuela
authors.initials: E
authors.lastname: Cagnano
authors.forename: Akiva
authors.initials: A
authors.lastname: Korn
authors.forename: Daniel
authors.initials: D
authors.lastname: Hayat
authors.forename: Zvi
authors.initials: Z
authors.lastname: Ram
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000235:genetics / Q000473:pathology / Q000601:surgery*; D003399:Craniotomy / Q000009:adverse effects*; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology*; D007521:Isocitrate Dehydrogenase / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000473:pathology; D009154:Mutation; D019635:Neurosurgical Procedures / Q000009:adverse effects*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012640:Seizures / Q000209:etiology* / Q000235:genetics*; D016896:Treatment Outcome
chemical_list: D007521:Isocitrate Dehydrogenase; C543588:IDH1 protein, human
keywords: 2-HG = 2-hydroxyglutarate; AED = antiepileptic drug; HGG = high-grade glioma; KPS = Karnofsky Performance Scale; LGG = low-grade glioma; LOS = length of hospital stay; SMA = supplementary motor area; awake craniotomy; brain tumors; isocitrate dehydrogenase 1 mutation; oncology; seizures; supplementary motor area