FLUORODOPA AND RACLOPRIDE PET ANALYSIS OF PATIENTS WITH MACHADO-JOSEPH-DISEASE

We performed [F-18]G-fluoro-L-dopa (6-FD) and [C-11]raclopride (RAG) P ET studies in six patients with Machado-Joseph disease (MJD) (age, 17 to 61 years; duration of illness, 3 to 10 years), normal controls (n = 10 in 6-FD-PET, n = 8 in RAG-PET), and patients with idiopathic parki nsonism (n = 15 in 6-FD-PET). The youngest patient with MJD had promin ent dystonia and pyramidal features (type 1 MJD), whereas the remainde r were prominently ataxic (types 2 and 3 MJD). Striatal RAC binding wa s normal in patients with MJD. Striatal 6-FD influx constants (Ki) wer e low in the range of idiopathic parkinsonism in two patients with MJD (youngest and oldest patients), whereas striatal Ki were normal in th e remaining patients with MJD. The impairment of the nigrostriatal dop aminergic pathway did not correlate with the phenotype, CAG repeat len gth, disease duration, or age of onset of patients with MJD. Our resul ts suggest that striatal D2 receptors are normal and the nigral damage is diverse in MJD.