Associating clinical outcomes and number of antiseizure medications in refractory status epilepticus

Background/objective: Prior studies have not directly evaluated the association between number of antiseizure medications (ASMs) and neurological outcomes. The objective of this study was to evaluate the association between the number of ASMs administered to patients in refractory SE and modified Rankin Scale (mRS) score at discharge. Methods: This was a retrospective cohort analysis of adults with SE from 2020 to 2023. Exclusion criteria included pregnancy, post-arrest myoclonus, and ≤ 2 non-benzodiazepine ASMs during admission. Patients were grouped by number of non-benzodiazepine ASMs received during admission (2, 3, or ≥4 ASMs). The primary outcome was mRS score at discharge. Results: The study included 287 patients (2 ASMs: 86, 3 ASMs: 82, ≥4 ASMs: 119), predominantly white (52.6 %) non-Hispanic (92.0 %) males (57.8 %) aged 55 – 60 years. Most patients had a history of epilepsy (73.9 %) and presented with convulsive SE (66.9 %). Patients receiving ≥ 4 ASMs had a higher median mRS score (4 vs. 1 vs. 1, p = 0.0001) and higher level of care at discharge (p = 0.0001) than comparators. Hospital and intensive care unit lengths of stay were longer in the ≥ 4 ASM group (12.2 and 6.0 days, respectively) than in comparator groups (2 ASMs: 5.5 and 2.2 days; 3 ASMs: 5.8 and 2.8 days; p < 0.001). Conclusions: The results of this study suggest that patients requiring ≥ 4 ASMs for treatment of SE have worse neurological outcomes. These results may inform treatment preferences for refractory SE and provide data for risk-benefit discussions.