Abstracts

Rationale: In patients with intractable temporal lobe epilepsy scalp electrodes are used to determine lateralization and localization of epileptic focus in presurgical evaluation. In some cases the detection of epileptic discharges from mesial temporal structure is inadequate by scalp electrodes. The aim of this study is to investigate the contribution of sphenoidal electrodes placed under fluoroscopy to anterior temporal electrodes in lateralization of bilateral refractory temporal lobe epilepsy. Methods: We performed a prospective study on 10 patients with intractable epilepsy who underwent Sphenoidal electrode placement at Katip Celebi University Ataturk Training and Research Hospital during the time period from 2010 to 2012 . Refractory temporal lobe epilepsy patients whose localization and lateralization of epileptic focus couldn t established with scalp video-EEG, or patients diagnosed bitemporal epilepsy with bitemporal seizure activity in video-EEG but no seizure onset identified, were evaluated. 5 females and 5 males were identified, ages 18-47 with medically intractable epilepsy. All patients were in the process of completing a presurgical evaluation. Sphenoidal electrodes placed double-sided to patients in sedation under fluoroscopy in the operating room. The appropriate position in order to view Foramen Ovale(FO) was given to the patient before starting the interference. The position was supine, shoulder supported by pad, head and neck were neutral in hyperextension position. Fluoroscopy displayed biplanar (lateral and submentovertical) images; Lateral for the entry point of the needle, submentovertical imaging for FO view . Electrode-needle system is inserted to the skin just 3-5 mm below the zygoma, through the middle of coronoid processes and condylar processes. It s advanced 1-2 cm parallel to the base of the skull. The process continued until the electrode tip reached anterolateral of foramen ovale by guidance of fluoroscopy.After the process is complete, the control of the SpE s last position displayed with three-dimensional skull CT .The measurements were performed and recorded several parameters . Patients monitorized at video-EEG unit.SpE and TE recordings obtained. Statistical analysis was performed by using SPSS (Statistical Package for Social Sciences) for Windows 15.0 package program. Pearson Chi-square and Fisher's exact test was used in comparison of statistical analysis of data . Results were evaluated in the confidence interval of 95%, p <0.05 was considered statistically significant, p> 0.05 was considered statistically insignificant. Results: The utility rate of sphenoidal electrode recordings were found to be 28.1%. 2 of 10 cases was not lateralized with scalp EEG were localized, 4 of 8 patients were lateralized. Conclusions: Sphenoidal electrodes and temporal electrodes are similar in their ability to detect seizures. The optimal placement of SpE with our technique provided additional localizing and lateralizing information in this series.