Brain Blood Flow Studies of Language and Memory

Positron Emission Tomography (PET) is a technique used to investigate the functional activity of the brain. The PET technique allows doctors to study the normal processes of the brain (central nervous system) of normal individuals and patients with neurologic illnesses without physical / structural damage to the brain. When a region of the brain is active, it uses more fuel in the form of oxygen and sugar (glucose). As the brain uses more fuel it produces more waste products, carbon dioxide and water. Blood carries fuel to the brain and waste products away from the brain. As brain activity increases blood flow to and from the area of activity increases also. Knowing these facts, researchers can use radioactive water (H215O) and PET scans to observe what areas of the brain are receiving more blood flow. This study is designed to use positron emission tomography (PET) with radioactive water (H215O) to determine the areas of the brain associated with memory and language. Patients participating in the study will be made up of normal volunteers, patients with epilepsy, and patients with other abnormalities related to the surface of the brain (non-epileptic focal cortical dysfunctions).