title: Seizures and the natural history of World Health Organization Grade II gliomas: a review.
abstract: OBJECTIVE
  The majority of adults with low-grade gliomas have seizures. Despite the frequency of seizures as initial symptoms and symptoms of later disease, seizures in relation to the natural course of low-grade gliomas have received little attention.
  
  
  METHODS
  In this review, we provide an update of the literature on the prognostic impact of preoperative seizures and discuss the tumor- and treatment-related factors affecting seizure control at later stages of the disease.
  
  
  RESULTS
  Seizures occur most frequently at disease presentation and predict a more favorable outcome. Initial seizures are correlated with tumor location and possibly indirectly to the molecular profile of the tumor. About 50% of all patients with seizures at presentation continue to have seizures before surgery. Maximal tumor resection, including resection of epileptic foci, is a valuable strategy for improving seizure control. In addition, radiotherapy and chemotherapy, as single therapies or in combination with surgery, have shown beneficial effects in terms of seizure reduction. Recurrent seizures after macroscopically complete tumor resection may be a marker for accelerated tumor growth. Recurrent seizures after an initial transient stabilization after radiotherapy and/or chemotherapy may be a marker for anaplastic tumor transformation.
  
  
  CONCLUSIONS
  Preoperative seizures likely reflect, apart from tumor location, intrinsic tumor properties as well. Change in seizure control in individual patients is frequently associated with altered tumor behavior. Including seizures and seizure control as clinical parameters is recommended in future trials of low-grade gliomas to further establish the prognostic value of these symptoms and to identify the factors affecting seizure control.
authors.affiliation: Department of Neuroscience and Neurology, Uppsala University, University Hospital, Uppsala, Sweden. Anja.Smits@neuro.uu.se
authors.forename: Anja
authors.initials: A
authors.lastname: Smits
authors.forename: Hugues
authors.initials: H
authors.lastname: Duffau
mesh_terms: D001932:Brain Neoplasms / Q000175:diagnosis* / Q000601:surgery; D005910:Glioma / Q000175:diagnosis* / Q000601:surgery; D006801:Humans; D011182:Postoperative Care / Q000379:methods; D012640:Seizures / Q000175:diagnosis* / Q000601:surgery; D016896:Treatment Outcome; D014944:World Health Organization