Positron Emission Tomography in Parkinson’s Disease

Abstract

ABSTRACT:Positron emission tomography (PET) allows the study of physiological and neurochemical processes which would otherwise be inaccessible, using radioactive labels on biological compounds to follow their fate in the body. By analysing changes of concentration with time we can measure blood flow, neuronal metabolism and receptor ligand interactions. In Parkinson’s disease (PD), PET has been used to examine the dopaminergic deficit and its relationship to motor performance. It has also been shown to detect asymptomatic dopaminergic lesions that have implications for the etiology of PD. In untreated PD there is increased density of D2 binding sites, while in chronically treated PD with motor fluctuations, D2 receptor density is reduced. [18F]-fluorodeoxyglucose studies of demented PD patients show a pattern of cortical metabolism similar to Alzheimer’s disease. Activation studies, which measure changes in blood flow during the performance of motor tasks, show reduced activation of medial frontal areas in PD.