PET study of striatal fluorodopa uptake and dopamine D₂ receptor binding in a patient with juvenile parkinsonism

We studied pre-synaptic and post-synaptic function in the striatum of a patient with juvenile parkinsonism (JP) using positron emission tomography (PET). [¹⁸F]6-fluorodopa (¹⁸FDOPA), ¹¹C-YM-09151-2 and [¹⁸F]fluoro-2-deoxy-D-glucose (¹⁸FDG) were used to measure fluorodopa uptake, dopamine D₂ receptor binding and glucose metabolism, respectively. In this patient, ¹⁸FDOPA accumulation was decreased markedly in the caudate nucleus and the putamen bilaterally. In the images of ¹¹C-YM-09151-2 and ¹⁸FDG, in contrast, no conspicuous changes were observed in the striatum. Thus our PET studies using ¹⁸FDOPA, ¹¹C-YM-09151-2 and ¹⁸FDG provide a useful approach for assisting the diagnosis of JP, because the present findings are different from the results in patients with dopa-responsive dystonia and hereditary progressive dystonia with marked diurnal fluctuation. Furthermore, our findings are of particular interest in relation to the pathogenesis of JP.