Abstracts

Rationale: Epilepsy surgery of refractory SE could be challenging. To identify the epileptogenic focus is very difficult because the EEG does not show clear-cut focal epileptiform abnormalities. Ictal 18F-FDG-PET is useful in delineating the epileptogenic area in view of possible resective surgery.Methods: Patients with refractory SE who had ictal PET, MRI and EEG monitoring were reviewed. All PET scans were conducted after the radiotracer was injected under EEG recording during ongoing SE. Epilepsy surgery was performed in selected cases guided by localizing information from ictal EEG, MRI and PET data.Results: Ictal F18-FDG-PET was obtained in 7 cases (M 3, F 4), who have refractory SE. Ictal PET was used as crucial localizing information together with MRI brain and EEG to make a decision for epilepsy surgery. Three cases had concordant localizing information of ictal PET and MRI data, but ictal PET provided more delineating localizing information. One case had a lesion demonstrated on the MRI, which on the wrong site, but ictal PET provide correct localizing information concordant with EEG data. One case had ictal SPECT that showed no localizing information, but ictal PET provided a correct localization. Three cases underwent for epilepsy surgery and all became seizure-free post-operatively. Ictal PET also showed well localizing information of the epileptogenic focus in cases who did not go for epilepsy surgery, because the refractory SE was stopped beforehand.Conclusions: Ictal PET is valuable tool used to identify the epileptogenic focus in refractory SE. It provided delineating localizing information that helps for planning epilepsy surgery in selected cases with refractory SE. A concordant data of a localizing information from ictal PET, ictal EEG and MRI provided a good surgical outcome. Also, the information of ictal PET in SE gives an understanding of a pathophysiology during the SE.