Temporal and spatial evolution of grey matter atrophy in primary progressive multiple sclerosis

Area of Science:

• Neuroimaging
• Neurology
• Neurodegeneration

Background:

• Grey matter (GM) atrophy is an early feature of primary progressive multiple sclerosis (PPMS).
• The regional and temporal patterns of GM atrophy progression and their association with clinical outcomes in early PPMS remain unclear.
• Understanding these patterns is crucial for assessing disease progression and evaluating potential treatments.

Purpose of the Study:

• To investigate the temporal and regional evolution of GM volume loss over five years in early PPMS.
• To examine the relationship between the rate of GM atrophy and disability progression in PPMS patients.
• To compare GM atrophy rates between PPMS patients and healthy controls.

Main Methods:

• Longitudinal voxel-based morphometry (VBM) was applied to serial MRI scans of 36 PPMS patients and 19 healthy controls over five years.
• Clinical assessments included the Expanded Disability Status Scale (EDSS) and MS Functional Composite (MSFC).
• Rates of local GM volume change were compared between groups and correlated with clinical outcomes.

Main Results:

• PPMS patients exhibited significantly greater GM volume loss than controls in regions including the cingulate cortex, thalamus, putamen, precentral gyrus, insula, and cerebellum.
• The rate of GM volume loss varied across brain regions, with the cingulate cortex showing the fastest decline.
• Higher rates of GM atrophy in the cingulate cortex correlated with greater MSFC-measured disability at five years.

Conclusions:

• GM atrophy in PPMS progresses at different rates across various brain regions, with early and steady involvement of the cingulate cortex.
• The rate of GM atrophy, particularly in the cingulate cortex, is associated with clinical disability progression in PPMS.
• These findings offer insights into PPMS neurodegeneration and highlight the potential of brain atrophy as an outcome measure in clinical trials.