Nuclear Medicine Imaging in Epilepsy

Abstract

For epilepsy patients who are not responding to anticonvulsant medications, surgery is an alternative treatment. A key issue in epilepsy surgery is the accurate localization of the “epileptogenic zone”. To date, pre-surgical evaluation of the epileptogenic network can be carried out by Electroencephalogram (EEG), video-EEG, magnetic resonance imaging, magneto-encephalography, single-photon emission computed tomography (SPECT) and positron emission tomography (PET). The interictal FDG-PET reveals hypometaboism at the epileptic focus, and it has been demonstrated to be much more sensitive than the interictal SPECT, and similarly sensitive to the ictal SPECT for the accurate localization of epileptogenic foci prior to surgical therapy. Visual assessment of 18F-FDG-PET is associated with interobserver and intraobserver variability. We have studied the issues of rigorous quantitation of FDG-PET brain studies and developed self-normalization technique. In addition to FDG-PET imaging, PET receptor imaging has also been demonstrated to provide significant insight into the mechanisms of neurotransmitters in epileptogenesis. In conclusion, we believe that nuclear medicine imaging can facilitate the identification of epileptic foci and investigate novel treatment for epilepsy.