Abstracts

Rationale: Febrile infection-related epilepsy syndrome (FIRES) is a devastating epilepsy syndrome in patient with previous normal development, but the underlying etiology of this disease is not clear. There were many hypothesizes about immunologic, genetic, metabolic causes. MRI findings are usually normal and do not explain for the deteriorating neuropsychologic process. Methods: In the beginning of the process of disease, 2-Deoxy-2[18F]fluoro-D-glucose (FDG) PET scan (18FDG-PET) was performed in 4 patients (age range 2 to 10 years, 3 boys, 1 girl) with satisfied the inclusion criteria for FIRES.Voxel-based analyses of cerebral glucose metabolism were performed using statistical parametric mapping and an adult control group for 3 patients older than 6 years. Results: The FDG-PET findings of 4 patients showed symmetric decreased glucose metabolism including bilateral frontal, temporal areas with sparing of both occipital cortex areas. Whereas, the brain MRI performed at the same time with FDG-PET scan showed non specific findings. SPM analysis was done in 3 of 4 patients, except 1 patient who is under the age of 6. Group comparison of 18FDG-PET images between FIRES patients and normal controls patients showed decreased glucose metabolism in large areas including inferior frontal, temporal, insular area and bilateral cerebellum at FDR corrected P<0.05. The Individual analysis in patients revealed significantly hypometabolic area in bilateral inferior frontal, temporal and insular areas, a relative concordant result between the visual and SPM analyses. Conclusions: Although this is small group study, FDG-PET scan showed global symmetric decreased glucose metabolism in all four FIRES patients before the changes of MRI of patients. these findings might suggest possible genetic or metabolic underlying causes in FIRES. 18FDG-PET findings suggest the reason of the intractabilities of epilepsy and catastrophic neuropsychologic dysfunctions.