The contribution of sphenoidal electrodes placed under fluoroscopy in lateralization of bilateral refractory temporal lobe epilepsy: a clinical study

Abstract

Aim: The aim of this study is to investigate the contribution of sphenoidal electrodes placed under fluoroscopic guidance to scalp electrodes, in the lateralization of temporal ictal onsets in bilateral refractory temporal lobe epilepsy. Also we determine the actual locations of sphenoidal electrodes by computerized tomography. Materials and Methods: We performed a prospective study on 10 patients with intractable epilepsy who has underwent sphenoidal electrode placement from 2010 to 2012. Refractory temporal lobe epilepsy patients whose localization and lateralization of epileptic focus couldn’t established with scalp EEG, or patients diagnosed bitemporal epilepsy with bitemporal seizure activity in video-EEG but no seizure onset identified, were evaluated. Sphenoidal electrodes placed double-sided to patients under sedation in the operating room. The control of the sphenoidal electrodes’ last position and several parameters displayed with 3D tomography. Patients monitorized at video-EEG unit. Simultaneously sphenoidal electrodes and scalp electrodes recordings obtained. Sphenoidal electrode lateralization results are compared with MRI, PET, SCALP EEG lateralization. Results: The utility rate of sphenoidal electrode recordings were found to be 28.1%. 2 of 10 cases lateralized were localized, 4 of 8 patients were lateralized by sphenoidal electrodes. Conclusion: Sphenoidal electrodes and scalp electrodes are similar in their ability to detect seizures. The optimal placement of sphenoidal electrodes with our technique provided additional localizing and lateralizing information in this series.