Status epilepticus following vaccination in children aged ≤24 months: A five-year retrospective observational study

Background: Status epilepticus is associated with significant morbidity and mortality. While vaccine proximate status epilepticus (VP-SE) has rarely been associated with cases of Dravet syndrome, it is not known whether VP-SE differs clinically from non-vaccine proximate status epilepticus (NVP-SE). Methods: Medical records of children aged <24 months, presenting to one of five Australian tertiary pediatric hospitals with their first episode of status epilepticus from 2013 to 2017 were identified using ICDcoded discharge diagnoses. Vaccination history was obtained from the Australian Immunisation Register. Hospitalization details, subsequent epilepsy diagnosis, and vaccination uptake were compared between VP-SE and NVP-SE cases. Results: Of 245 first status epilepticus hospitalization with immunization records, 35 (14%) were VP-SE and 21 (60%) followed measles-containing vaccines. Vaccine-proximate status epilepticus cases had a median age of 12.5 months [IQR 7.1-14.73], 23 (66%) were in males, 15 (43%) were febrile status epilepticus and 17 (49%) had an infection confirmed. There were no significant differences in hospitalization duration (P = 0.50) or intensive care unit admission (P = 0.42) between children with VP-SE compared to children with NVP-SE. Children with no history of seizures at their first VP-SE had longer hospitalizations, were more likely to require intensive care unit admission, but were less likely to have a subsequent diagnosis of epilepsy than children with previous seizures at their first VP-SE. Conclusion: First VP-SE was predominantly associated with a measles-containing vaccine at 12-months of age. Seizure severity was no different between first VP-SE and first NVP-SE. In children with VP-SE, subsequent seizure admissions and epilepsy diagnosis were associated with having seizure prior to their first SE. Crown Copyright CO 2022 Published by Elsevier Inc. All rights reserved.