Positron emission tomography studies in movement disorders. 
Positron emission tomography (PET) scanning provides a sensitive means of detecting and characterizing regional changes in brain metabolism and receptor binding in movement disorders.  PET allows the quantitative examination of regional cerebral blood flow, regional glucose and oxygen metabolism, and brain pharmacology.  In this article, the particular use of PET to determine the effects of therapeutic stereotactic surgery, including transplantation, on brain function in Parkinson's disease and in tremor patients is highlighted.