The short-term and long-term outcome of febrile infection-related epilepsy syndrome in children

Abstract

Background: The febrile infection-related epilepsy syndrome (FIRES) is a catastrophic epileptic encephalopathy which developed the refractory status epilepticus following or during a nonspecific febrile illness. To analyze the short-term and long-term outcome of FIRES in the children, we retrospectively analyzed the related data.

Methods: The motor outcome was evaluated by modified Rankin scale (mRS). Poor motor outcome was defined as a mRS score of 4 or higher at discharge. Significant motor decline was defined as the mRS difference more than 2 before hospital admission and at discharge.

Results: We totally enrolled 25 patients for analysis. Four patients were expired during hospitalization, and one patient was lost to follow-up after discharge. Therefore, a total 20 patients were finally analyzed. The age of disease onset ranged from 1.6 to 17.2 years (mean: 9.6 ± 4.4 years). Newly acquired epilepsy and cognitive deficit occurred in 100% and 61%, respectively. The duration of the anesthetic agents ranged from 7 to 149 days (mean: 34.2 ± 36.1 days). The duration of anesthetic agent usage (p = 0.011), refractory epilepsy (p = 0.003), and the use of ketogenic diet (p = 0.004) were significantly associated with the poor long-term motor outcome, and the number of anesthetic agents tended to be associated with the poor long-term motor outcome (p = 0.050). In-hospital mortality was 16%. Significant functional decline at discharge occurred in 100%. However, there was improvement in long-term follow-up.

Conclusion: The outcome of FIRES is poor with significant mortality and morbidities. Refractory epilepsy with cognitive deficit in survived cases is common, but improvement is possible.

Keywords: Cognitive outcome; Febrile infection-related epilepsy syndrome; Motor long-term outcome; Refractory epilepsy.