[Magnetic resonance spectroscopy in Parkinson's disease and multiple system atrophy].

Recent advances in magnetic resonance spectroscopy(MRS) allow to assay noninvasively key molecules of brain metabolism in living patients. There are several reports of MRS in Parkinson's disease(PD) and multiple system atrophy(MSA). 1H-MRS of the striatum revealed the reduced NAA/Cr and Cho/Cr ratio in MSA patients and the preserved NAA/Cr and Cho/Cr ratio in PD patients. The reduced NAA/Cr ratio probably reflects striatal neuronal loss. 1H-MRS of the striatum showed increased Cho/Cr ratio in the "on" state compared with that in the "off" state in the PD patients. The increased Cho/Cr ratio may reflect some membrane alteration or change of choline metabolism in PD with the "wearing-off" phenomena. Although studies are still preliminary, MRS shows great possibility for aiding in the differential diagnosis of parkinsonism and it will contribute to a better understanding of the pathogenesis of PD and MSA.