PET (POSITRON EMISSION TOMOGRAPHY)
Positron emission tomography is a test used to visualize the metabolic activity (glucose/sugar use by cells) of the brain. The substance administered during a PET scan is glucose (sugar) tagged with a radioisotope (18F- fluoro-deoxy-glucose). Once administered, a scan is then performed to detect the how much of this radioisotope goes to different parts of the brain. Areas of the brain that are less metabolically active will consume less glucose and will contain lower amounts of radioisotope. Those areas of the brain that consume less glucose (hypometabolic areas) are usually those areas that correspond to the seizure focus. The test is performed on an outpatient basis in the nuclear medicine department. Since this test is sensitive only if performed in the interictal (between seizure) period, it is preferable that the patient undergo simultaneous EEG recording, to make sure that no seizures have occurred before, during, or after the study