Positron emission tomography in partial epilepsies: the clinical point of view

Epilepsy research using positron emission tomography (PET) has advanced our understanding of the pathophysiology and neurochemical correlates of both focal and generalized epilepsies, but from the clinical viewpoint its major contribution has been in the presurgical evaluation of patients with medically intractable partial seizures. Depending on the tracer used, PET may provide information on regional cerebral blood flow and glucose metabolism, and the binding of specific ligands to receptors that are thought to be related to the genesis and propagation of epileptic activity. In this communication, we discuss the diagnostic yield, limitations and perspectives of 18F-fluorodeoxyglucose (FDG) and 11C-flumazenil (FMZ) PET in partial epilepsies. The current evidence regarding the pathophysiology of the focal changes is also presented, with an emphasis on issues which must be carefully addressed for effective and reliable clinical research.