Changes of deep gray matter magnetic susceptibility over 2 years in multiple sclerosis and healthy control brain

Area of Science:

• Neuroimaging
• Neurodegeneration
• Magnetic Resonance Imaging

Background:

• Multiple sclerosis (MS) involves both myelin and iron abnormalities in deep gray matter (DGM).
• Longitudinal characterization of these changes using advanced MRI techniques is lacking.

Purpose of the Study:

• To investigate longitudinal tissue changes related to myelin and iron in the DGM of MS patients.
• To utilize quantitative susceptibility mapping (QSM) for sensitive detection of these pathological alterations.

Main Methods:

• Prospective study with 120 MS patients and 40 healthy controls.
• Quantitative susceptibility mapping (QSM) MRI performed at baseline and 2-year follow-up.
• Statistical analysis (ANOVA, t-tests) to compare cross-sectional and temporal differences in brain magnetic susceptibility.

Main Results:

• MS patients exhibited significantly higher susceptibility in the caudate and globus pallidus, and lower susceptibility in the thalamus compared to controls.
• Susceptibility increased in the caudate nucleus in both MS patients and controls over two years.
• Thalamic findings in MS patients suggest a biphasic pathology involving initial iron/myelin changes followed by later iron depletion/calcium deposition.

Conclusions:

• QSM is a sensitive tool for detecting longitudinal iron and myelin-related changes in MS DGM.
• MS DGM exhibits distinct susceptibility patterns, with caudate and globus pallidus showing increased susceptibility and thalamus showing decreased susceptibility.
• The observed thalamic changes in MS patients indicate a complex, multi-stage pathological process over time.