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Dopaminergic Function and Dopamine Transporter Binding Assessed With Positron Emission Tomography in Parkinson Disease

2002; American Medical Association; Volume: 59; Issue: 4 Linguagem: Inglês

10.1001/archneur.59.4.580

1538-3687

Maria-João Ribeiro, Marie Vidailhet, Christian Loc’h, Corinne Dupel, Jean Paul Nguyen, M. Ponchant, Frédéric Dollé, Marc Peschanski, Philippe Hantraye, Pierre Césaro, Yves Samson, Philippe Rémy,

Genetic Neurodegenerative Diseases

Background: Measuring progression of Parkinson disease (PD) using positron emission tomography may help demonstrate the efficacy of neuroprotective treatments.To date, 18 F-dopa has been the gold standard to measure presynaptic dopaminergic function in PD, but this tracer might overestimate the rate of neuronal death in PD because its uptake also depends on dopamine turnover rather than exclusively on the density of dopaminergic terminals in the striatum.The latter might be assessed using newly developed ligands of the membrane dopamine transporter.Objective: To compare the striatal uptakes of 18 F-dopa and 76 Br-FE-CBT, a dopamine transporter ligand, in patients with PD.Patients and Methods: The striatal uptakes of 76 Br-FE-CBT and 18 F-dopa were compared using positron emission tomography in 10 patients with early PD and 8 with advanced PD. Correlation of uptakes with motor performance was investigated. Results:The reduction in 76 Br-FE-CBT binding to 43% of control values was more severe than the reduction in 18 F-dopa uptake (63% of control values) in the putamen of patients with early PD.No significant difference was found between either tracer's uptake in the putamen of patients with advanced PD. Motor performance was highly correlated to 18 F-dopa uptake, whereas correlation to 76 Br-FE-CBT binding was weak.Conclusions: Uptake of 18 F-dopa may be up-regulated in early PD, suggesting a compensatory increase of dopamine synthesis in surviving dopaminergic terminals.Positron emission tomography dopamine transporter ligands and 18 F-dopa give complementary information on the presynaptic status of the nigrostriatal dopaminergic system and might be associated to investigate the efficacy of neuroprotective treatments in PD.