Febrile infection-related epilepsy syndrome (FIRES) in adults: a case report and review of factors associated with survival

INTRODUCTION: Febrile infection-related epilepsy syndrome (FIRES) is a subtype of new onset refractory status epilepticus (NORSE) that has, in recent years, been recognized to not only affect pediatric but adult patients too. While inpatient mortality in adult-onset FIRES has been suggested to be higher than in pediatric patients, little is known about the factors associated with survival, hampering research into developing prognostic and stratification models and also posing a challenge for clinical communications and decision making. METHODS: We report a fatal case of FIRES in a 21-year-old lady and performed a review of literature involving adult-onset FIRES from 1 Aug 2022 to 17 Aug 2024, analyzing the data to identify factors associated with survival of the initial hospital stay. RESULTS: Including our case, 49 patients of adult-onset FIRES were identified. Of the 47 patients who had MRI brain scan findings described at any time during the illness, 35 patients (74.5%) had abnormal findings in at least one scan, and the most common site of abnormality was the temporal lobe (59.6%). A total of 41 patients survived the initial hospital stay (83.7%). The presence of MRI temporal lobe abnormalities was associated with survival at discharge (p = 0.013), and the association remained significant on multivariate analysis with corticosteroid usage. CONCLUSION: In adult-onset FIRES, MRI temporal lobe abnormalities may be associated with survival beyond the acute phase. Our study findings suggest that the site of MRI abnormalities in FIRES may have value in the clinical stratification and prognostication of adult-onset FIRES.