Brainstem Metabolites in Multiple System Atrophy of Cerebellar Type: 3.0-T Magnetic Resonance Spectroscopy Study

Background: The aim of this study was to find biomarkers of disease severity in multiple system atrophy of cerebellar type by imaging disease specific regions using proton magnetic resonance spectroscopy on a 3.0 T system. Methods: We performed proton magnetic resonance spectroscopy separately in the pons and medulla on 12 multiple system atrophy of cerebellar type patients and 12 age and gender matched control subjects. The metabolite concentrations were estimated from single-voxel proton magnetic resonance spectra measured by point resolved spectroscopy, which were then correlated with clinical severity using Part I, II, and IV of the unified multiple system atrophy rating scale. Results: Proton magnetic resonance spectroscopy showed that myo-inositol concentrations in both the pons and medulla were significantly higher in multiple system atrophy of cerebellar type patients compared to those of the control subjects (P < 0.05). By contrast, total N-acetylaspartate (the sum of N-acetylaspartate and N-acetylaspartylglutamate) and total choline compounds concentrations in both the pons and medulla were significantly lower in multiple system atrophy of cerebellar type patients compared to control subjects (P < 0.05). Creatine concentration in the pons was significantly higher in multiple system atrophy of cerebellar type patients compared to the control subjects (P < 0.05). Furthermore, a significant correlation was found between the myo-inositol/creatine ratio in the pons and clinical severity, defined by the sum score of unified multiple system atrophy rating scale (I+II+IV) (r = 0.76, P < 0.01). Conclusion: Proton magnetic resonance spectroscopy, in conjunction with a 3.0 T system, can be feasible to detect part of pathological changes in the brainstem, such as gliosis and neuronal cell loss, and the metabolites can be used as biomarkers of clinical severity in multiple system atrophy of cerebellar type patients. (C) 2011 Movement Disorder Society