Clinical features and surgical outcomes in temporal lobe epilepsy with amygdala enlargement - a single tertiary center study

Objective: To analyze and summarize clinical features and surgical outcomes in temporal lobe epilepsy with amygdala enlargement (TLE-AE) in a single tertiary center. Methods: Patients with TLE-AE admitted to the Neurological Disease Center of Peking University International Hospital from January 2016 to September 2022 were continuously collected. The clinical data of TLE-AE patients were retrospectively analyzed. Results: A total of 19 patients with TLE-AE were included. The average age at onset was (29.0 ± 14.5) years and all patients had focal impairment awareness seizure (FIAS). Ten (52.6%) patients were in line with drug-resistant epilepsy and 8 cases received surgical treatment. Focal temporal interictal epileptiform discharges on scalp electroencephalography were exclusively present ipsilateral to AE in 15 (78.9%) patients. Stereo-electroencephalography analysis found the ictal onset zone involved not only the enlarged amygdala but also the hippocampus in 2 patients. Two patients who responded well to antiseizure medication exhibited AE remission on follow-up MRI. Histopathology of the amygdala showed focal cortical dysplasia (FCD) in 7 patients and ganglioglioma in 1 patient. The 8 surgical patients were followed up for 13-79 months after operation. Six (75.0%) patients achieved Engel class Ia or I outcome, whereas 2 cases did not fully respond to the surgery (Engel class II). Conclusions: Patients with TLE-AE had a later age of seizure onset and FIAS was common. The epileptogenic zone in TLE-AE patients may be located in the enlarged amygdala and ipsilateral hippocampus. AE might be a secondary seizure-induced change in a subset of patients with favorable responses to drugs. As for drug-resistant patients, FCD may be the most common pathological change and surgical treatment could be taken into consideration.