Abstracts

Rationale: Lesion in amygdala is one of the causes of mesial temporal lobe epilepsy (MTLE). The adjacent hippocampus is not necessarily epileptogenic. We investigated the seizure and neuropsychological outcomes after selective resection of lesion in amygdale sparing hippocampus. Methods: We reviewed our database between July 2008 to August 2015 in Taipei Veterans General Hospital, Taiwan. Patients with MTLE who had lesion limited to the amygdala and underwent amygdala lesionectomy sparing the hippocampus were enrolled. Presurgical work-up included long term video-EEG monitoring, brain MRI, fluorodeoxyglucose-positron emission tomography, and neuropsychological tests. Electrocorticography was also performed during the surgery. Postoperative seizure outcomes at 2 years were obtained. Wechsler Adult Intelligence Scale, the third edition, Wechsler Memory Scale Quality, the third edition, and Quality of Life(QOLIE-89) were used to evaluate the neuropsychological and QOL outcomes after surgery. We also reviewed all postoperative MRI to assure that the hippocampus was spared. Results: Twenty patients, 13 male and 7 female, were followed for more than 2 years after surgery. Among them 12 (60%) were seizure-free, 7 had occasional auras (35%), and one had disabling seizure while skipping AEDs. The most common pathological finding were tumor (55%), followed by vascular malformation (25%). Seven cases had intraoperative recoding of hippocampus after removal of amygdala and five of them showed spikes. Fourteen patients completed the neuropsychological and QOL assessment before and after surgery. The QOLIE-89 one year after the surgery showed improvement compared to the pre-surgical conditions in total scores, epilepsy and physical health domains (p = 0.011, 0.008, and 0.008, respectively). The neuropsychological outcomes showed no significant change in IQ or associated index. There was no change in verbal memory including word lists, verbal paired association, and logical memory. However, significant improvement in delayed face recognition was noted. (p = 0.016) Conclusions: MTLE with amygdala lesion after lesionectomy with sparing of hippocampus could achieve excellent seizure outcomes and QOL outcomes without negative impact on cognition. Funding: Nil