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.