Gray and normal-appearing white matter in multiple sclerosis: an MRI perspective

Area of Science:

• Neuroimaging
• Neurology
• Pathology

Background:

• Multiple sclerosis (MS) involves gray matter and normal-appearing white matter (NAWM) abnormalities beyond focal lesions.
• Conventional MRI often misses significant gray matter pathology in MS.
• Quantitative MRI reveals NAWM abnormalities suggesting axonal damage, demyelination, and glial changes, though histopathology remains unclear.

Purpose of the Study:

• To review recent advances in MRI studies of gray matter and NAWM in MS.
• To highlight the need for improved detection and characterization of MS-related cortical pathology.
• To emphasize the importance of understanding the relationship between NAWM/gray matter changes and clinical outcomes.

Main Methods:

• Discussion of recent advances in quantitative magnetic resonance imaging (MRI) techniques.
• Review of studies investigating NAWM abnormalities using quantitative MRI.
• Examination of gray matter pathology detection using advanced MRI techniques like 3D double-inversion recovery.
• Analysis of cortical thickness and atrophy measurements for neurodegeneration assessment.

Main Results:

• Quantitative MRI detects NAWM abnormalities consistent with axonal damage, demyelination, and glial cell increase.
• Advanced MRI techniques show promise for detecting cortical pathology previously missed by conventional MRI.
• Cortical thickness and atrophy measurements quantify neurodegeneration in MS.

Conclusions:

• Further in vivo MRI studies are crucial for understanding NAWM and gray matter changes in MS.
• Spatially specific investigations, potentially using diffusion fiber-tracking, are needed to link NAWM/cortical changes to clinical deficits.
• Integrating advanced MRI findings with clinical data will improve comprehension of MS progression and impact.