An SEEG study of bilateral temporal lobe epilepsy suggested by scalp EEG

Abstract

Objective To explore the lateralizing value of stereotactic electroencephalography (SEEG) in bilateral temporal lobe epilepsy (BTLE) suggested by scalp EEG and to assess the surgical outcomes. Methods A retrospective study was conducted on the clinical features and SEEG monitoring results of 10 patients who were diagnosed as BTLE based on scalp EEG and underwent SEEG implantation from January 2014 to December 2015 at Renji Hospital, School of Medicine, Shanghai Jiaotong University. According to the SEEG results, anterior temporal lobectomy with amygdalohippocampectomy (ATL-AH) was performed for unilateral temporal lobe epilepsy (UTLE) and BTLE with unilaterally dominant epileptic focus, and neuromodulation was performed for BTLE without unilaterally dominant epileptic focus. Results SEEG monitoring data revealed UTLE in 7 out of the 10 patients and BTLE in the other 3 patients including 1 with unilaterally dominant epileptic focus. Among the 8 patients undergoing ATL-AH, 6 patients were classified as Engel I and 2 as Engel Ⅱ post surgery. Neuromodulation was performed in 2 patients and both reported an Engel class III outcome. Conclusions In patients with BTLE suggested by scalp EEG, unilateral onset might be identified in most cases which could achieve good surgical outcomes following ATL-AH. SEEG seems to be a safe and effective method to lateralize BTLE as indicated by scalp EEG. Patients with UTLE and BTLE with unilaterally dominant epileptic focus could obtain good outcomes (Engel class I and II) post ATL-AH. Moreover, neuromodulation seems to be an effective therapy for BTLE without unilaterally dominant epileptic focus. Key words: Epilepsy, temporal lobe; Stereoelectroencephalography; Neurosurgical procedures; Evaluation studies