Brain Anatomy and Function

Anatomy of the Brain Separated into right and left halves by the Interhemispheric Fissure The Central Sulcus runs down & forward The Lateral Fissure runs backward & up

Frontal and Temporal Lobes Thought Voluntary movement Speech motor Covers 1/3rd of area of the brain Memory Auditory function Complex movements

Parietal and Occipital Lobes Sensation Touch Pressure Pain Temperature Texture Position/spatial orientation Vision Visual processes Reading Complex movements

Medulla Oblongata, Cerebellum, and Pons Large Muscle Coordination Balance Walking, Writing Respiration Heart rate Continuous with the spinal cord (2.5 cm) Pons Complex movements Relay between the cerebral hemispheres and the cerebellum

Basal Ganglia and Thalamus “The Brakes” Modifies movement on a minute-to-minute basis Inhibits Movement Coordination Cortical relay

Limbic System Attention Sensory gateway Memory processing Rage Aggression Sexuality Appetite/Thirst

The Nerve Cell Synaptic junction

Lichtman, J., et al Washington University 2002 Neurotransmitters Serotonin – major – emotions, judgment, eating and sleep disorders (associated with frontotemporal disorder) Glutamate/GABA - Widespread, anxiety, sleep, (Valium targets this) Dopamine – memory, mood, movement, Parkinson's Disease, psychiatric problems Endorphins – relief of pain, (Morphine targets this) Lichtman, J., et al Washington University 2002

Serotonin Glutamate/GABA Normal functions Emotions Judgment Sleep Involved in most facets of brain function Imbalances Depression Suicidal behavior Anxiety Impulsive behavior Eating disorders Imbalances Memory disturbances Sleep disturbances Anxiety

Dopamine Endorphins Normal functions Normal functions Imbalances Relieve pain Induce euphoria Normal functions Mood Movement Memory Imbalances Movement disorders Schizophrenia Addiction

Normal Aging Brain Brain weight and volume decrease Grooves widen Surface smoothes Neurofibrillary tangles increase Understanding normal variation is key to interpretation

Brain Glucose Metabolism – Normal Normal brain tissue actively metabolizes glucose and its analogue (F-18 FDG) Glucose metabolism provides 95% of the energy required for brain function FDG is irreversibly trapped within brain cells in proportion to its use because it cannot be broken down or stored unlike glucose

FDG-PET Normal Brain Metabolism

FDG-PET Abnormal Brain Imaging Dementia Memory loss Cognitive Decline Epilepsy Localization of a seizure focus Tumor Assessment Radiation Necrosis vs Tumor Grade Objective Imaging Diagnosis of Movement Disorders Huntington’s Disease Parkinson’s Disease

Dementia Diagnosis: Current Methods History and physical examination Neurologist (Sens. = 50-80%) Neuropsychologist / Neuropsychiatrist Neuropsychological testing MRI / CT Blood testing Functional Neuroimaging (SPECT/ PET/MR) Sens.=80-90%

Summary Normal Brain Anatomy Normal Brain Function Current PET Brain Applications: Diagnosis of Dementia Seizure Localization Tumor Assessment Objective Imaging Diagnosis of Movement Disorders (not CMS approved)

Contributors Rebecca Trunnell Hyman Coordinator of PET Services Clinical PET of West County - Creve Coeur, MO Kevin L. Berger, M.D. Assistant Professor of Radiology Director of PET Imaging Michigan State University – East Lansing, MI