Abstracts

Rationale: To evaluate metabolic pattern of FDG-PET abnormalities in children with epilepsia partialis continua (EPC).Methods: We evaluated 18 EPC patients (12M:6F), including detailed clinical, neuroimaging (MRI, FDG-PET), and electrophysiological data. FDG-PET was acquired during EPC, and continuous EEG monitoring was performed during FDG uptake period.Results: Mean age at EPC onset was 7.3±3.3 years. Ten patients had left-sided, 7 had right-sided and one had bilateral involvement. All of them had a history of prior seizures, including history of suspected Rasmussen encephalitis in 14 patients, and one who presented with EPC only. Multiple seizure types were noted, including absence, simple, complex and generalized seizure types. FDG-PET was abnormal in all 18 patients showing both areas of hypo- and hypermetabolism in 13, and only areas of hypometabolism in the remaining 5 patients. EEG during PET was normal in 3 and showed spike & wave discharges with or without diffuse slowing in 15). In 4 patients, FDG-PET showed bilateral abnormalities even though the clinical manifestations were unilateral with EEG showing bilateral sharp wave activity in only one of them. One patient had FDG-PET hypometabolism ipsilateral to the EPC manifestations (leg, arm and tongue involvement), without any EEG changes on either side; a subsequent transcranial magnetic stimulation study also suggested abnormality in the ipsilateral cortex (consistent with FDG-PET findings). MRI was completely normal in 6 patients.Conclusions: FDG PET can be valuable in the evaluation of children with EPC, as it reveals cortical abnormalities, even when EEG or MRI is normal, and frequently reveals more extensive functional abnormalities than suggested by the MRI.