Accelerated long-term forgetting of verbal information in unilateral temporal lobe epilepsy: Is it related to structural hippocampal abnormalities and/or incomplete learning?

The factors contributing to accelerated long-term forgetting (ALF) are not yet clear. In this study, a 12-item word list was presented repeatedly to 23 patients with temporal lobe epilepsy (TLE) and 27 control participants (NC) until it was recalled completely on two consecutive trials or until 12 trials were undertaken. Compared to NCs, patients with hippocampal lesions and those who failed to learn the list showed ALF by one day post learning, but the alternative patient groups also showed ALF when tested after seven days. Overall, our findings suggest that in patients with TLE neither a preserved hippocampus nor intact learning protects against ALF.