Spatial Correlation of Pathology and Perfusion Changes within the Cortex and White Matter in Multiple Sclerosis

Area of Science:

• Neuroimaging
• Neurology
• Radiology

Background:

• The relationship between white matter (WM) and cortical gray matter (GM) disease in multiple sclerosis (MS) is not fully understood.
• Previous studies have not utilized perfusion MR imaging to assess this spatial correlation.

Purpose of the Study:

• To investigate the association between lobar WM and cortical GM volume and perfusion in MS.
• To differentiate the pathophysiology of WM and GM damage in MS using quantitative MR perfusion imaging.

Main Methods:

• Quantitative MR perfusion imaging (CBF, CBV, MTT) was performed on 19 secondary-progressive MS, 19 relapsing-remitting MS, and 19 healthy controls.
• Multivariate linear regression analysis, corrected for clinical factors, assessed correlations between perfusion and volume measures in global and lobar WM, cortical GM, and lesions.
• Bonferroni adjustment was applied for statistical significance.

Main Results:

• Global cortical GM and WM volumes were reduced in MS patients compared to controls, with varying patterns.
• Cortical GM perfusion (CBF, CBV) was reduced in SPMS but not RRMS compared to controls.
• WM perfusion did not significantly differ across groups, and associations between WM and GM volume/perfusion were weak, suggesting independent pathologies.

Conclusions:

• The weak correlation between lobar WM and cortical GM volume loss and perfusion reduction suggests independent pathophysiological processes.
• Perfusion MR imaging provides insights into the distinct disease mechanisms affecting WM and GM in MS.
• These findings highlight the complexity of MS pathology and the need for targeted therapeutic strategies.