Abstracts

Rationale: While the primary objective of seizure localization in the epilepsy monitoring unit (EMU) is to capture seizures, this must be balanced by the morbidity associated with seizure clusters. Seizure clusters that occur during monitoring pose both neurophysiological and clinical complications (Haut 2002); a seizure cluster may interfere with identification of predominant seizure onset zone, result in injuries and increase risk for post-ictal psychosis. Abortive medications are routinely given to break up a seizure cluster, but there is no standardization or consensus on which abortive is most effective with regards to seizure recurrence or time to next abortive use. The purpose of this study was to determine if there are differences in seizure recurrence risk and time to next abortive use with the 4 abortive types (Ativan 0.5 mg, Ativan 1 mg, Ativan 2 mg and “other”) used at Johns Hopkins epilepsy monitoring unit (JHEMU).

Methods: This is a retrospective chart review of 187 patients who were admitted to JHEMU from January 1, 2019, to December 31, 2019. For each patient, the following information was collected: age at admission, gender, which event type was captured (epileptic seizures, non-epileptic seizures, both), length of stay, number of antiseizure medications (ASM) at admission, scalp or intracranial EEG monitoring, abortive (Ativan 0.5 mg, Ativan 1 mg, Ativan 2 mg or “other”) used to break up a seizure cluster during the admission, time to next seizure and/or abortive after first abortive was given. We then utilized Cox proportional hazards model with failure event defined as recurrent seizure after first abortive given, and observed time interval as time to seizure recurrence and time to next abortive after first abortive given.

Results: Of the 113 patients who had epileptic seizures, 74 patients needed abortive medications to be given during their EMU stay. Thirty patients (40.5%) were given Ativan 0.5 mg, 34 patients (45.9%) were given Ativan 1 mg, 4 patients (5.4%) were given Ativan 2 mg and 6 patients (8.1%) were given “other seizure medication” as their abortive for a seizure cluster. Forty-five patients of the 74 patients (60.8%) who received the first abortive were given a second abortive. Twenty-two patients of the 30 patients (73.3%) who received Ativan 0.5 mg as a first abortive needed a second abortive seizure medication at median of 6.5 hours (SD = 27.9). Nineteen out of 34 patients (55.6%) who received Ativan 1 mg as a first abortive needed a second abortive seizure medication at a median of 13.6 hours (SD = 22.5). One out of 4 patients (25%) who received Ativan 2 mg as a first abortive needed a second abortive at 96.3 hours. Three out of 6 patients (50%) who received "other seizure medications" as a first abortive needed a second abortive at a median of 10.7 hours (mean = 30; SD = 37.1). K-wallis test showed statistically significant difference (p=0.03) between the medians of the 4 abortive types.

Conclusions: Our results suggest that Ativan 2 mg was more effective in preventing seizure clustering in the EMU compared to lower doses of Ativan or other seizure medications. Ativan 2 mg was also associated with longer times to next seizure. Larger studies need be done to corroborate these results.

Funding: None