Hippocampal atrophy, epilepsy duration, and febrile seizures in patients with partial seizures

Background: Previous studies have suggested a variety of factors that may b e associated with the presence of hippocampal formation (HF) atrophy in pat ients with complex partial seizures (CPS), including a history of complex o r prolonged febrile seizures (FS), age at seizure onset, and epilepsy durat ion. Objective: To determine whether epilepsy duration is related to HF atr ophy. Methods: We performed MRIs on 35 patients with uncontrolled CPS who h ad temporal lobe ictal onset on video-EEG. None had evidence for an alien t issue lesion or extra-hippocampal seizure onset. All had a history of secon dary generalization. Brain structures were drawn on consecutive images and pixel points summed from successive pictures to calculate volumes. Results: Nine patients with a history of complex or prolonged FS had smaller ipsila teral HF volume and ipsilateral/contralateral ratio than did patients witho ut a history of FS. Epilepsy duration had a significant relation to ipsilat eral HF volume and ipsilateral/contralateral ratio. In a multivariate analy sis, the effect of duration, but not age at onset or scan, was significant. Patients with a history of FS did not have earlier age at epilepsy onset o r longer duration. Conclusions: A history of FS predicted the severity of H F atrophy in our patients. Age at onset or study was not a significant fact or. Epilepsy duration, however, did have a significant effect, suggesting t hat, after an initial insult, progressive HF damage may occur in patients w ith persistent seizures.