FDG-PET AND MRI IN TEMPORAL-LOBE EPILEPSY - RELATIONSHIP TO FEBRILE SEIZURES, HIPPOCAMPAL SCLEROSIS AND OUTCOME

Objective - To correlate the volumetric head magnetic resonance imagin g (MRT) and fluorodeoxyglucose-positron emission tomography (FDG-PET) scan findings with the history intracarotid amobarbital procedure, pat hology, and outcome in patients with medically refractory temporal lob e epilepsy. Material and methods - Thirty-eight patients with temporal lobe epilepsy treated surgically following a comprehensive presurgica l evaluation. Follow-up ranged from 12 to 44 months, Results - Volumet ric MRI showed ipsilateral hippocampal atrophy in 29 (76%), and PET sc an showed ipsilateral temporal hypometabolism (PET-TH) in 31 (81.5%) o f patients. Eighty-three percent of those patients with hippocampal sc lerosis on MRI (MRI-HS) had ipsilateral PET-TH, Sixty-six percent of p atients with MRI-HS had a history of prolonged febrile convulsions or a childhood febrile illness accompanied by convulsions, and 77% of pat ients with MRI-HS had pathologically proven hippocampal sclerosis (HS) . Ninety percent became seizure free or had rare seizures. Conclusion - FDG-PET scans and head MRIs were complementary; 95% of patients had either MRI-HS or temporal hypometabolism. MRI-HS correlated with a his tory of febrile seizures and pathologically demonstrated hippocampal s clerosis. Ninety-three percent of patients had focal functional defici ts on the epileptogenic side, Concordance between PET temporal hypomet abolism and MRI-HS correlated with better outcome.