Abstracts

Rationale: Febrile status epilepticus (FSE) is associated with hippocampal injury and often precedes intractable temporal lobe epilepsy. Respiratory viruses are a common cause of childhood fevers and can give rise to FSE. Previous clinical observations identified unexpectedly low FSE cases in the year 2020 alongside the outbreak of Sars-CoV-2. Only three febrile status cases were seen in the first six months of the outbreak, as opposed to the expected number of ten. The goal of the study was to measure the association between the presence of respiratory viral load in the community and the number of FSE cases at Children’s National Hospital.

Methods: Retrospective chart reviews were performed on all FSE patients presenting to the Children’s National emergency department (ED) since 2014. Eligible patients were between 1 month and 6.0 years old and had a seizure(s) lasting ≥ 30 minutes accompanied by a fever ≥ 38.4 ˚C within 24 hours of cessation. Patients were excluded if they had prior afebrile seizures, known seizure disorder, neurological impairments, or global developmental delay. In order to examine community viral load, we used monthly positive respiratory PCR tests performed on patients admitted to our ED. Linear regression analyses were used to test the association between monthly rates of positive viral pathogens and monthly FSE case numbers. For viruses with more than one type (e.g., RSV A and RSV B), we tested them both individually and combined.

Results: A total of 98 FSE cases presented to the emergency department between March of 2014 and October of 2020. The mean age of febrile status patients was 22.3 ± 14.7 months; the incidence of FSE ranged from 0 to 5 cases per month (average 1.3/month). An average of 96.3 ± 191.6 respiratory PCRs were performed per month. Most viruses were not associated with FSE. However, HHV-6 (R² = 0.25) and Sars-CoV-2 (R² = 0.20) were found to be moderately associated with FSE. Governmental data regarding positive cases of influenza A and B within the District of Columbia were compared to ED data between the years 2015 and 2020 and showed a regression correlation of R² = 0.52.

Conclusions: The incidence of febrile status epilepticus is not strongly associated with community respiratory viral load as measured by the positivity of respiratory viral PCR testing in this ED. The moderate negative association observed between Sars-CoV-2 and FSE supports the hypothesis that decreased presentation of febrile status is a result of increased quarantining by children in the community due to COVID-19. The positive association of HHV-6 with FSE supports previous literature. The strong association between D.C. and ED influenza data shows that the ED viral identification is representative of the community viral load.

Funding: Please list any funding that was received in support of this abstract.: NINDS R21NS109669.