• multiple system atrophy;
  • ataxia;
  • neurodegenerative disorders;
  • parkinsonian syndromes;
  • MR imaging;
  • voxel-based morphometry


To visualize and quantify disease progression in multiple system atrophy (MSA) from cerebellar type (MSA-C), we combined two magnetic resonance imaging (MRI) techniques, voxel-based morphometry (VBM) and 3D-based volumetry. Patients suffering from MSA-C (n = 14) were imaged twice with an interval of 2.0 ± 0.2 years. We first applied VBM to map brain morphology changes between MSA patients and controls and to identify brain areas that showed a significant amount of atrophy. Using 3D-based volumetry, we confirmed that in MSA-C patients, the brainstem including medulla and pons, vermis and cerebellar hemispheres, caudate nucleus and putamen showed significant atrophy compared with controls. Next, we used 3D-based volumetry to analyze the atrophy rates. Atrophy rates in patients with MSA were significantly different from controls for putamen (−11.4% ± 2.6%/year), vermis (−12.3% ± 2.9%/year), and cerebellar hemispheres (−6.6% ± 1.1%/year). The results show that 3D-based MRI volumetry is a tool that allows the disease progression of MSA to be followed over a time period of 2 years and suggest that it may serve as a surrogate marker in clinical trials to measure disease progression. © 2006 Movement Disorder Society