Anticonvulsant drug therapy after aneurysmal subarachnoid hemorrhage: A critically appraised topic

Background: Seizures are a complication of aneurysmal subarachnoid hemorrhage (aSAH). Objective: To evaluate whether antiepileptic drug (AED) prophylaxis after aSAH reduces seizure risk and whether it is associated with improved neurological outcomes. Methods: The objective was addressed through the development of a critically appraised topic that included a clinical scenario, structured question, search strategy, critical appraisal, assessment of results, evidence summary, commentary, and bottom line conclusions. Neurology consultants and residents, a medical librarian, clinical epidemiologists, and content experts in the fields of epilepsy, neurosurgery, and critical care contributed to the review and placed the evidence in clinical context. Results: There were no relevant randomized, controlled trials that addressed the question. A post hoc analysis of data from 4 trials of tirilazad for aSAH showed that prophylactic AED therapy was associated with worse Glasgow Outcome Scale scores at 3 months (odds ratio 1.56, 95% confidence interval 1.16-2.10; P = 0.003) but numerous confounders limit data interpretation. Conclusions: There are insufficient data to support or refute the prophylactic use of AED therapy after aSAH. Randomized, controlled trials are needed to address the efficacy and risks of AEDs in this setting and should take into account factors such as aneurysmal factors (location, hemorrhage grade, degree of parenchymal injury), type of aneurysm surgery (clip vs. coil), and evaluate the timing and duration of AED use.