Brain volume patterns in corticobasal syndrome versus idiopathic Parkinson's disease

Patients with a corticobasal syndrome (CBS) present a rare form of atypical parkinsonism characterized by asymmetric clinical symptoms and progressive motor and nonmotor impairment, such as apraxia, alien limb phenomenon, aphasia, myoclonus, dystonia, and cognitive impairment. At early stages, clinical differentiation between CBS and idiopathic Parkinson's disease (IPD) can be challenging.

Using high-resolution T1-weighted images and voxel-based morphometry (VBM), we sought to identify disease-specific patterns of brain atrophy in a small sample of CBS and IPD patients at early stages of disease. We acquired MR images of 17 patients diagnosed with CBS and compared them with MR images of 17 subjects affected by IPD. Images were preprocessed and analyzed using VBM.

When compared to each other, the CBS and IPD patients of our cohort showed differences in regional gray and white matter volume depending on the diagnosis, specifically in the superior longitudinal fascicle.

In our small patients' group, VBM was able to detect changes in regional gray and white matter volume between patients affected by CBS and patients with IPD as early as 1.5-2 years after the onset of the first motor symptoms.