Abstracts

Rationale: Status epilepticus (SE) is a neurological emergency with a high mortality rate. The SE Severity Score (STESS) uses age, seizure semiology, level of alertness and history of epilepsy to predict mortality, but does not include the etiology of the seizures as a factor. In 2014, the International League Against Epilepsy (ILAE) classified the etiology of SE as acute known, progressive known, remote known, status in electroclinical syndromes and cryptogenic. In 2017, a different ILAE classification included the categories structural, metabolic, infectious, immune, genetic and unknown. There is a paucity of studies describing how these different categories correlate with mortality. The main objective of this study was to evaluate how the ILAE 2014 and 2017 etiological groupings correlated with in-hospital mortality.

Methods: This study is a retrospective data analysis using electronic health records from a tertiary care center. Patients at least 18 years old that had a clinical or electrographic diagnosis of SE were included. Those with hypoxic-ischemic encephalopathy were excluded. 602 subjects that had continuous EEG monitoring between July/2017 and December/2019 were screened. 435 were excluded due to not meeting criteria for SE, meeting exclusion criteria, or having insufficient chart documentation, leaving 167 individuals in the final sample. Demographic, clinical, radiographic and laboratory data were collected and patients were divided using the ILAE 2014 and ILAE 2017 etiology classifications. The STESS score was also calculated for each patient. In-hospital mortality was then compared separately for the categories in both classifications. Continuous variables were compared using t-test or Mann-Whitney U test. Categorical data were analyzed using chi-square test or Fisher’s exact test. Univariate logistic regression models were created to determine the odds ratio of patients dying. SAS Enterprise Guide 7.15 HF3 was used to conduct the statistical analysis.

Results: The results are summarized in Tables 1 and 2. Significant findings included a difference in mortality for the different etiology groups using the ILAE 2014 classification (p-value 0.02). In the total sample, mean age was significantly different between patients that lived vs. died (60.11 vs 69.2 years, p-value 0.01). For every one year increase, patients were 1.05 times more likely to die (p-value 0.01). The mean STESS Score was significantly different between patients that lived vs. died (2.52 vs 3.93, p-value < .01). For every one point increase in the STESS score, patients were 1.77 times more likely to die (p-value < 0.01).