Extended Antiepileptic Drug Prophylaxis and Late Onset Seizures in Aneurysmal Subarachnoid Hemorrhage

Abstract

Background: The indication and optimal duration of antiepileptic drug (AED) prophylaxis after aneurysmal subarachnoid hemorrhage (SAH) remains controversial. Our institution practices routine seizure prophylaxis for variable durations at the discretion of the neurosurgeon and neuro-intensivist. Given the propensity of late onset seizures to progress to chronic epilepsy, we sought to investigate the efficacy of extended AED prophylaxis in reducing the risk of late seizures. Methods: This retrospective study analyzed 36 patients who were admitted to our neurosurgical intensive care unit (NICU) over a 2-year period (1st November 2015 to 31st October 2017). All hospital admissions records, electronic medication records as well as outpatient visits up to 1 year were reviewed. Late onset seizures were defined as seizures occurring more than 7 days post-intervention (or presentation if no intervention was performed) up to 1 year of follow-up. Results: Majority of the patients received Levetiracetam (94%) as seizure prophylaxis and late onset seizures occurred in 6 (17%) of the patients. Those patients who received a greater proportion of in-patient stay with AED prophylaxis had a statistically significant lower risk of developing late seizures (OR = 0.964, 95%, p = 0.02). Although the value tended towards benefit (OR = 0.382) for AED > 21 days in-hospital, the result was not statistically significant (p = 0.307). Conclusion: An extended duration of AED prophylaxis, in particular Levetiracetam, may confer some benefit in reducing risk of developing late seizures. However, the optimal duration of therapy is yet to be determined and further large multi-centered randomized studies are necessary.