Voxel-based morphometry and voxel-based relaxometry in multiple system atrophy-a comparison between clinical subtypes...

Area of Science:

• Neuroimaging
• Neurology
• Neurodegeneration

Background:

• Multiple system atrophy (MSA) is a rare, fatal neurodegenerative disorder.
• It affects multiple areas of the nervous system, including the basal ganglia, cerebellum, and brainstem.
• Clinical variants include cerebellar (MSA-C) and parkinsonian (MSA-P) types.

Purpose of the Study:

• To investigate structural brain changes in MSA using voxel-based morphometry (VBM) and voxel-based relaxometry (VBR).
• To compare brain abnormalities between MSA-C and MSA-P variants.
• To correlate structural changes with disease duration and severity.

Main Methods:

• Voxel-based morphometry (VBM) to assess gray and white matter volume.
• Voxel-based relaxometry (VBR) to measure relaxation rate R2.
• Analysis of 48 MSA patients (32 MSA-C, 16 MSA-P) and 46 healthy controls.

Main Results:

• MSA-C showed gray matter loss in the cerebellum, thalamus, putamina, and insular cortex, with white matter loss in the brainstem.
• VBR revealed decreased R2 in the cerebellum, brainstem, and insular cortex in MSA-C.
• MSA-P exhibited gray matter reduction in the cerebellum, midbrain, putamina, and insular cortex.
• Structural differences were more pronounced in infratentorial regions for MSA-C compared to MSA-P.

Conclusions:

• Both MSA-C and MSA-P involve widespread gray matter loss, with distinct patterns.
• White matter and R2 changes in the cerebellum and brainstem are significant in MSA-C.
• VBM and VBR are valuable tools for characterizing MSA neuropathology and differentiating variants.