The Quantitative 18-fluorodeoxyglucose PET Study in the Differential Diagnosis between Idiopathic Parkinson's Disease and Multiple System Atrophy

ABSTRACT

BACKGROUND: Overlapping clinical features of idiopathic Parkinson's disease (IPD) and multiple system atrophy (MSA) make it difficult to conduct an accurate differential diagnosis. We performed a quantitative F18- fluorodeoxyglucose PET (FDG PET) and measured the striatal and cerebellar glucose metabolism to evaluate the efficacy of a FDG PET study in the differential diagnosis between IPD and MSA. METHODS: This study included 19 patients with IPD, 28 patients with MSA (MSA-P : MSA-C = 19 : 9) and 12 age matched normal controls. A FDG PET study was performed in all subjects and the original PET image was corrected with the radioactivity curve obtained by repetitive sampling of the radial arterial blood. RESULTS: The measurements of striatal and cerebellar glucose metabolisms of the patients with MSA-P were significantly lower than those of the patients with IPD (P<0.001). However, the measurement of the caudate nucleus provided the most reliable clue for the differential diagnosis between IPD and MSA-P (sensitivity 94.7% and specificity 94.7%). In the patients with MSA-C, the glucose metabolism of the cerebellar vermis (P<0.001), cerebellar cortex (P<0.001) and putamen (P<0.05) was significantly lower than those of the patients with IPD. CONCLUSIONS: Quantitative FDG PET is a useful and reliable method in making a differential diagnosis between IPD and MSA.