title: Cerebral Arteriovenous Malformations and Epilepsy, Part 2: Predictors of Seizure Outcomes Following Radiosurgery.
abstract: OBJECTIVE
  Seizure outcomes after arteriovenous malformation (AVM) management with radiosurgery are incompletely understood. In this case-control study, we aim to determine the incidences and define the predictors of seizure improvement and de novo seizures in patients with AVM with and without seizures at presentation, respectively.
  
  
  METHODS
  We evaluated our institutional AVM radiosurgery database to determine the factors that were associated with favorable seizure outcome (seizure improvement or lack of de novo seizures). In patients with seizures at presentation, seizure improvement was defined as decreased seizure frequency or complete seizure remission. In patients without seizures at presentation, de novo seizures were defined as new-onset seizures after radiosurgery. Logistic regression analyses were performed to identify predictors of favorable seizure outcome.
  
  
  RESULTS
  In 229 patients with seizures at presentation, the rates of seizure improvement and seizure remission were 57% and 20%, respectively. Prior AVM hemorrhage (P = 0.015), longer follow-up (P < 0.0001), and lack of hemorrhage after radiosurgery (P = 0.048) were independent predictors of seizure improvement in the multivariate analysis. In 778 patients without seizures at presentation, the overall rate of de novo seizures was 1.7%. Prior AVM hemorrhage (P = 0.001) and higher Spetzler-Martin grade (P = 0.018) were independent predictors of the absence of de novo seizures in the multivariate analysis. AVM obliteration was not significantly associated with seizure outcomes after radiosurgery.
  
  
  CONCLUSIONS
  Radiosurgery provides reasonable rates of seizure improvement for patients with AVM who present with seizures. For patients with AVM without seizures at presentation, the risk of de novo seizures after radiosurgery is very low, obviating the need for prophylactic antiepileptic drug therapy. Further investigation of epilepsy in patients with AVM undergoing stereotactic radiosurgery should be considered with validated outcome measures and prospective study design.
authors.affiliation: Department of Neurosurgery, University of Virginia School of Medicine, Charlottesville, Virginia, USA.
authors.forename: Dale
authors.initials: D
authors.lastname: Ding
authors.affiliation: Department of Neurology, University of Virginia School of Medicine, Charlottesville, Virginia, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Quigg
authors.affiliation: Department of Neurosurgery, University of Virginia School of Medicine, Charlottesville, Virginia, USA.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Starke
authors.affiliation: Department of Neurosurgery, University of Virginia School of Medicine, Charlottesville, Virginia, USA.
authors.forename: Chun-Po
authors.initials: CP
authors.lastname: Yen
authors.affiliation: University of Virginia School of Medicine, Charlottesville, Virginia, USA.
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Przybylowski
authors.affiliation: Department of Neurosurgery, University of Virginia School of Medicine, Charlottesville, Virginia, USA.
authors.forename: Blair K
authors.initials: BK
authors.lastname: Dodson
authors.affiliation: Department of Neurosurgery, University of Virginia School of Medicine, Charlottesville, Virginia, USA. Electronic address: jps2f@virginia.edu.
authors.forename: Jason P
authors.initials: JP
authors.lastname: Sheehan
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D004827:Epilepsy / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000150:complications* / Q000453:epidemiology / Q000601:surgery*; D020300:Intracranial Hemorrhages / Q000150:complications / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011446:Prospective Studies; D016634:Radiosurgery / Q000379:methods*; D012640:Seizures / Q000453:epidemiology* / Q000209:etiology; D016896:Treatment Outcome
keywords: Epilepsy; Gamma Knife; Intracranial arteriovenous malformations; Neurologic manifestations; Radiosurgery; Seizures; Vascular malformations