Epilepsy duration, febrile seizures, and cerebral glucose metabolism

Purpose: Studies using magnetic resonance imaging have shown that reduced hippocampal volume is associated with a history of febrile seizures, the duration of epilepsy. and the number of generalized tonic-clonic seizures. It is uncertain whether these factors have the same influence on functional as on structural measures of the integrity of the epileptogenic zone. Methods: We used positron emission tomography (PET) with fluorine IS 2-deoxyglucose to study 91 patients with temporal lobe seizure foci localized by ictal video-EEG. PET was performed in the awake interictal resting state with ears plugged and eyes patched. We recorded surface EEG during injection (5 mCi) and the 30-min uptake period. We used a standard template to analyze PET scans. Results: A significant negative relation was found between the duration of epilepsy and hippocampal glucose metabolism ipsilateral to the epileptic focus. Patients with a history of either any febrile seizures, or complex. or prolonged febrile seizures, did not have greater hypometabolism ipsilateral to the epileptic focus than did patients without a febrile seizure history. We found no effect of generalized tonic-clonic seizure history. Conclusions: Longer epilepsy duration is associated with greater hypometabolism. Suggesting that epilepsy is a progressive disease.