# Clinical characteristics of 27 children with febrile infection‐related epilepsy syndrome in a single center

## TL;DR

This study examines the clinical features and risk factors in 27 children with febrile infection-related epilepsy syndrome (FIRES), finding a high mortality rate and the impact of factors like fever and diet on outcomes.

## Contribution

The study identifies seizure onset with fever, periodic discharges, and ketogenic diet as independent risk factors for mortality in FIRES patients.

## Key findings

- FIRES patients had a mortality rate of 33%, with seizure onset combined with fever and periodic discharges linked to worse outcomes.
- Ketogenic diet (KD) was associated with lower mortality, fewer seizures, and better functional outcomes compared to non-KD patients.
- A linear relationship was observed between body temperature and convulsion frequency in FIRES patients.

## Abstract

To investigate the clinical characteristics of febrile infection‐related epilepsy syndrome (FIRES). We used trajectory analysis and logistic regression analysis to investigate the clinical characteristics and prognostic risk factors respectively. Twenty‐seven patients (16 males) were included. The median age of onset was 7 (IQR: 4–9) years. Routine cerebrospinal fluid (CSF) examination was normal. Electroencephalogram (EEG) showed frequent microseizures and electroseizures in all patients. Eight patients had claustrum signs in the acute phase. Anesthetics and anti‐seizure medications (ASM) were used in all patients. All patients received immunotherapy, including plasma exchange (n = 4), immunoglobulin (n = 26), and corticosteroids (n = 19). Trajectory diagrams of seizure showed 6 patients had bimodal disease course. Besides, we found there may be a linear relationship between body temperature and convulsion frequency (R
2 = 0.25). The median Glasgow outcome scale (GOS) was 3 (IQR: 1–4). Nine deaths occurred, including abandonment of treatment (n = 3), hemodynamic instability (n = 3), brain hernia (n = 2), and brain hernia with hemodynamic instability (n = 1). Seizure onset combined with fever (p = 0.003), periodic discharge (p = 0.002), and non‐ketogenic diet (non‐KD) (p = 0.005) were independent risk factors for death. The KD group (n = 10) had lower mortality (p = 0.009), lower convulsion frequency at latest follow‐up (p < 0.001), less ASM (p = 0.002), and higher GOS (p < 0.001) than non‐KD group (n = 17). Therefore, some FIRES patients may have bimodal disease course. There may be a linear relationship between body temperature and convulsion frequency. Seizure onset combined with fever, periodic discharge and KD may affect the prognosis.

Our febrile infection‐related epilepsy syndrome (FIRES) patients had a poor prognosis with a mortality up to 33%. Seizure onset combined with fever, periodic discharges and ketogenic diet (KD) may affect the prognoses of FIRES patients. Among the above 3 independent risk factors for death, KD is a controllable factor for clinicians.