Febrile Infection-Related Epilepsy Syndrome (FIRES) in children: a retrospective cohort study.

This study aimed to analyze the clinical and electroencephalogram (EEG) data of a cohort of children diagnosed with Febrile Infection-Related Epilepsy Syndrome (FIRES) to provide a comprehensive evaluation of the acute and chronic phases of the disease and their associated clinical outcomes. A retrospective cohort study involved 19 pediatric patients admitted to two tertiary centers in Egypt. Data collection encompassed clinical manifestations, laboratory investigations, brain magnetic resonance imaging (MRI), and EEG findings. The study included 19 children with FIRES, with a median age at onset of 7 years, and 68.4% were male. All patients presented with fever before the onset of illness, followed by early convulsions that rapidly progressed to status epilepticus (SE). Seizures began 2-9 days after fever onset, with the acute phase lasting a median of 29 days and SE lasting a median of 20 days. Seizure types were primarily focal (52.6%). Abnormal MRI findings were observed in 84.2% of cases. During the acute phase, EEG showed a complete loss of normal background activity in all patients. In the chronic phase, EEG background activity gradually normalized, and epileptiform activity remained prevalent in all patients, with multifocal spikes and slow waves in 94.7% and extreme delta brush noted in 36.8% of patients. FIRES in children is associated with significant morbidity and mortality, characterized by prolonged refractory seizures and enduring neurological impairments. Early recognition and aggressive management are crucial in improving clinical outcomes. What is Known: • Febrile Infection-Related Epilepsy Syndrome (FIRES) is a rare, severe, and often fatal form of epileptic encephalopathy that has been a focus of significant attention in medical literature over the past two decades.  What is New: • This study provides a detailed analysis of clinical and EEG data in children with FIRES, highlighting distinct characteristics of the acute and chronic phases. •The findings underscore the critical need for early recognition and aggressive management to address prolonged refractory seizures and mitigate enduring neurological impairments.