MRI gray and white matter measures in progressive supranuclear palsy and corticobasal syndrome

We evaluated MRI measures of gray and white matter damages in 19 patients with progressive supranuclear palsy (PSP), 11 with corticobasal syndrome (CBS), and 14 healthy subjects (HS) to differentiate patients with PSP from those with CBS. We calculated surface-based maps of the cortical volume, cortical thickness, surface area, and voxel level maps of sub-cortical volume, and diffusion tensor imaging parameters using automated scripts implemented in FreeSurfer and FSL toolboxes. No significant differences in cortical volume loss were observed between PSP and CBS. When cortical volume was divided into cortical thickness and surface area, cortical thickness in peri-rolandic brain regions was significantly smaller in CBS than in PSP patients, whereas surface area was significantly smaller in PSP than HS. We also found widespread volume loss in sub-cortical structures in patients with PSP and CBS in comparison to HS. Both patient groups displayed diffusion tensor imaging abnormalities: compared to HS, widespread fractional anisotropy and radial diffusivity changes were observed in PSP, whereas axial and radial diffusivity changes were prominent in CBS. Mini-mental state examination positively correlated with diffusion changes in patients with PSP. In conclusion, cortical thickness, surface area, and diffusion tensor imaging parameters may be sensitive enough to help differentiate patients with PSP from those with CBS.