title: Epilepsy after subarachnoid hemorrhage: the frequency of seizures after clip occlusion or coil embolization of a ruptured cerebral aneurysm: results from the International Subarachnoid Aneurysm Trial.
abstract: OBJECTIVE
  The aim of this study was to determine the probability of seizures after treatment of a ruptured cerebral aneurysm by clip occlusion and coil embolization, and to identify the risks and predictors of seizures over the short- and long-term follow-up period.
  
  
  METHODS
  The study population included 2143 patients with ruptured intracranial aneurysms who were enrolled in 43 centers and randomly assigned to clip application or coil placement. Those patients suffering a seizure were identified prospectively at various time points after randomization, as follows: before treatment; after treatment and before discharge; after discharge to 1 year; and annually thereafter.
  
  
  RESULTS
  Two hundred thirty-five (10.9%) of the 2143 patients suffered a seizure after randomization; 89 (8.3%) of 1073 and 146 (13.6%) of 1070 in the endovascular and neurosurgical allocations, respectively (p = 0.014). In 19 patients the seizure was associated with a rehemorrhage. Of those patients who underwent coil placement alone, without additional procedures, 52 suffered a seizure, and in the group with clip occlusion alone, 91 patients suffered a seizure. The risk of a seizure after discharge in the endovascular group was 3.3% at 1 year and 6.4% at 5 years. In the neurosurgical group it was 5.2% at 1 year and 9.6% at 5 years. The risk of seizure was significantly greater in the neurosurgical group at both 2 years and at up to 14 years (p = 0.005 and p = 0.013, respectively). The significant predictors of increased risk were as follows: neurosurgical treatment allocation, hazard ratio (HR) 1.64 (95% CI 1.19-2.26); younger age, HR 1.54 (95% CI 1.14-2.13); Fisher grade > 1 on CT scans, HR 1.34 (95% CI 0.62-2.87); delayed ischemic neurological deficit due to vasospasm, HR 2.10 (95% CI 1.49-2.94); and thromboembolic complication, HR 5.08 (95% CI 3.00-8.61). A middle cerebral artery (MCA) aneurysm location was also a significant predictor of increased risk in both groups; the HR was 2.23 (95% CI 1.57-3.17), with the probability of seizure at 6.1% and 11.5% at 1 year in the endovascular and neurosurgery groups, respectively.
  
  
  CONCLUSIONS
  The risk of seizures after coil embolization is significantly lower than that after clip occlusion. An MCA aneurysm location increased the risk of seizures in both groups.
authors.affiliation: Department of Neurology, Royal Victoria Infirmary, Newcastle Upon Tyne, United Kingdom.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Hart
authors.forename: Mary
authors.initials: M
authors.lastname: Sneade
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Birks
authors.forename: Joan
authors.initials: J
authors.lastname: Rischmiller
authors.forename: Richard
authors.initials: R
authors.lastname: Kerr
authors.forename: Andrew
authors.initials: A
authors.lastname: Molyneux
mesh_terms: D017542:Aneurysm, Ruptured / Q000453:epidemiology* / Q000209:etiology; D004621:Embolization, Therapeutic / Q000009:adverse effects / Q000706:statistics & numerical data*; D004827:Epilepsy / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000009:adverse effects / Q000706:statistics & numerical data*; D011183:Postoperative Complications / Q000453:epidemiology / Q000517:prevention & control; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D013345:Subarachnoid Hemorrhage / Q000453:epidemiology* / Q000209:etiology; D013525:Surgical Instruments / Q000706:statistics & numerical data