Febrile infection-related epilepsy syndrome (FIRES): therapeutic complications, long-term neurological and neuroimaging follow-up

Purpose: To understand the long-term neurological outcomes and chronological changes of brain MRIs in patients with febrile infection-related epilepsy syndrome (FIRES). Methods: From December 2000 to May 2016, 29 patients diagnosed with FIRES were collected retrospectively. The demographic distribution, clinical manifestations, neuroimaging findings, and treatment methodology were described. Follow-up clinical outcomes and chronological evolution of neuroimaging findings were analyzed. Results: The median age of disease onset was 8.9 years. The median duration of hospitalization was 87 days. During the period of hospitalization, more than 50% of patients exhibited complications such as skin rash, liver function impairment, and arrhythmia. Abnormal findings were found in 38% of neuroimaging studies in the initial study and in 87% of the follow-up brain MRI. Focal abnormal signal changes over the periventricular white matter suggested the more extensive lesions would be associated with a poorer clinical outcome. The median duration of follow-up was 5 years in 23 patients. In total, 87% of patients exhibited residual and/or refractory epilepsy. Regarding cognitive function, 26% of patients had normal intelligence quotient, 26% had learning disability and mild to moderate mental retardation, and 48% had severe mental retardation or vegetative status. The mortality rate at acute stage was 10%, and that at chronic stage was 13%. Conclusions: Liver function impairment, skin rash, and arrhythmia are frequently seen during hospitalization for FIRES at the acute stage of disease course. The higher grade of periventricular white matter lesions suggested poorer neurological outcomes. Studies on the pathomechanism of FIRES are crucially needed so that new treatment strategies for FIRES can be developed, which may improve long-term outcomes. (C) 2018 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.