Epileptic amnesic syndrome.

Thirteen patients with "epileptic amnesic syndrome" (EAS) presented with adult-senile onset of a severe memory complaint that started before or at the same time as seizures. All were diagnosed as temporal lobe epilepsy (TLE). The seizures were stereotyped, with only short loss of contact and oral automatisms, and because they were not obvious or disturbing, they remained underdiagnosed for a long time. Nine cases also presented attacks of transient anteroretrograde amnesia after the seizures--called "epileptic amnesic attacks" (EAA)--during which the patients were able to perform complex actions. EAA are similar to the attacks of transient global amnesia (TGA) but are more frequent, shorter, accompanied by clear-cut clinical and electroencephalographic epileptic manifestations, and respond favorably to antiepileptic therapy. Neuropsychological investigation ruled out global mental deterioration, showing only selective memory impairment in a few long-term tasks and dissociation between formal findings and the relevant memory complaint. These cases have uniform anamnestic, clinical, and neuropsychological characteristics and represent a particular clinical expression of TLE, namely EAS. We suggest that an epileptic origin be entertained in patients presenting repeated amnesic attacks resembling TGA or who complain of persistent memory disturbance, after more common etiologies have been excluded.