Memory after temporal lobe epilepsy surgery: Risk and reward

Anterior temporal lobectomy (ATL) is a common surgical intervention for drug-resistant mesial temporal lobe epilepsy (mTLE) that results in seizure freedom for approximately two-thirds of patients and reduces seizure frequency in about 15% more.1 Felicitous seizure outcome often is accompanied by stability of cognitive performance because the resected anterior temporal lobe, especially the hippocampus, was structurally and functionally abnormal before ATL, as demonstrated by MRI, PET, EEG, and neuropsychological assessment. In some cases, however, the postsurgical summary is not all fit for banner and blazon. Devastating memory loss after ATL has been quite rare since it was discovered more than 50 years ago that bilateral hippocampal ablation or injury could result in permanent global amnesia. However, a sizable minority of patients with ATL experience a post-ATL decrease in performance on one or more standardized memory tests. During the past 20 years, the potential epilepsy, cognitive, and demographic variables associated with this post-ATL memory decline …