Hippocampal and amygdaloid damage in partial epilepsy - A cross-sectional MRI study of 241 patients

Patients with drug-refractory temporal lobe epilepsy (TLE) often have hippo campal and amygdaloid damage. The present study investigated the factors as sociated with the occurrence and severity of damage in patients with partia l epilepsy. Magnetic resonance imaging was used to measure the volumes of t he hippocampus and the amygdala in 241 patients with different durations of epilepsy. We also investigated the association of damage with the location of seizure focus and clinical factors (age at onset of seizures, lifetime seizure number and medical history of complex febrile convulsions, intracra nial infection or status epilepticus) with regression analysis. We found th at high lifetime seizure number (P < 0.05), history of complex febrile conv ulsions (P < 0.01), and age 15 years at the time of the first seizure (P < 0.01) were significant risk factors far reduced hippocampal volume in TLE p atients. The severity of amygdaloid damage did not differ between TLE patie nts with different durations of epilepsy or seizure frequency, but complex febrile convulsions (P < 0.05) and intracranial infection (P < 0.05) were a ssociated with amygdaloid damage. In patients with extratemporal or unclass ified partial epilepsy, the hippocampal and amygdaloid volumes did not diff er when patients with different durations of epilepsy were compared with co ntrols. The present findings indicate that a high seizure number, the occur rence of complex febrile convulsions, and an early onset of seizures contri bute to hippocampal volume reduction in patients with TLE. The data provide d have important implications with regard to early and effective management and seizure control in vulnerable patients. (C) 2001 Published by Elsevier Science B.V.