S1-4. PET imaging of epilepsy

If we can visualize the epileptogenic lesion, the intractable epilepsy might be cured by the resective surgery. PET is a common clinical imaging tool, and it can evaluate and visualize brain function quantitatively and multidimensionally with various radio ligands. (18) FDG-PET and (11) C-flumazenil-PET are mainly used in the clinical settings, and they showed the decrease of glucose metabolism and binding in the epilepsy focus. In this decade, many PET radio-ligands are developed for positive imaging of epileptogenic lesion. The first target is neuroinflammation, such as 18 kDa-translocator protein (TSPO). (11) PK-11195-PET showed increase of TSPO binding in the focus in animal model, however, this alteration is unclear in human clinical study. Glutamate receptors are believed to be a novel biomarkers of epileptogenesis in future, and our experimental study showed the possibility that it could be a positive marker. Furthermore, other PET studies for neurotransmitters reported the role of opioids, cannabinoids, acetylcholine, and dopamine in modulating neuronal hyperexcitability. PET has the possibility not only to visualize the epileptic foci, but also elucidate of the mechanism of epileptogenesis.