Voxel-Based Meta-Analysis of Gray Matter Abnormalities in Multiple System Atrophy

Area of Science:

• Neuroimaging and Neuropathology
• Neurodegenerative Diseases

Background:

• Multiple system atrophy (MSA) is a progressive neurodegenerative disorder with two main clinical subtypes: parkinsonism (MSA-P) and cerebellar (MSA-C).
• Understanding the distinct neuropathological underpinnings of these subtypes is crucial for accurate diagnosis and targeted therapeutic strategies.

Approach:

• A systematic literature search was conducted across PubMed, Embase, and Web of Science for voxel-based morphometry (VBM) studies comparing MSA subtypes with healthy controls.
• Quantitative meta-analysis was performed using the Signed Differential Mapping (ES-SDM) method, with validation through Seed-based d Mapping with Permutation of Subject Images (SDM-PSI) and familywise error rate (FWE) correction.

Key Points:

• Both MSA-P and MSA-C subtypes exhibited cerebellar and cerebral cortex atrophy.
• Basal ganglia atrophy was uniquely identified in the MSA-P subtype.
• Specific cortical regions showed differential atrophy patterns between MSA-P and MSA-C, aligning with their clinical presentations.

Conclusions:

• The study identified distinct patterns of gray matter volume loss in MSA-P and MSA-C, supporting their classification as separate clinicopathological entities.
• These findings provide neuroimaging evidence for the differing pathophysiology underlying the clinical manifestations of MSA subtypes.