18F-FDG PET and FIRES

Fever-induced refractory epileptic encephalopathy in school-age children (FIRES) is a recently described epileptic entity whose etiology remains unknown. Brain abnormalities shown by MRI are usually limited to mesial-temporal structures and do not account for the catastrophic neuropsychologic findings.

Research published in the January issue of The Journal of Nuclear Medicine shows that positron emission tomography (PET) scans can offer an evaluation of cognitive dysfunction of fever-induced refractory epileptic encephalopathy(FIRES), its evolution and further prognosis.

FIRES, a recently named condition, occurs in previously healthy children who, after a brief fever, experience acute seizures that are resistant to medication and last for several weeks. After the seizures stop, children are left with severe cognitive dysfunction, mainly involving language, memory and behavior.

The study, "18F-FDG PET Reveals Frontotemporal Dysfunction in Children with Fever-Induced Refractory Epileptic Encephalopathy," was conducted with eight patients diagnosed with FIRES. The patients were given a neuropsychologic evaluation, a brain MRI and an 18F-FDG PET scan. Severe cognitive dysfunction was noted, and while the MRI tests showed no abnormalities for the patients, the PET scans reported significant cognitive impairment.

Researchers compared the FIRES patients with a pseudo-control group of epilepsy patients with normal MRI and PET scan results. Using statistical parametric mapping, an objective approach to analyzing brain activity, the study exposed that the brain dysfunction was related to the epilepsy in the FIRES patients.