Brain Iron at Quantitative MRI Is Associated with Disability in Multiple Sclerosis

Area of Science:

• Neuroimaging
• Neurodegeneration
• Magnetic Resonance Imaging

Background:

• Multiple sclerosis (MS) involves complex neurodegenerative processes affecting deep gray matter.
• Assessing iron deposition in deep gray matter is crucial for understanding MS evolution and disability.
• Quantitative susceptibility mapping (QSM) offers a novel method to measure iron-related changes.

Purpose of the Study:

• To investigate deep gray matter susceptibility in MS using QSM.
• To evaluate the association between deep gray matter susceptibility and clinical disability in MS patients.
• To compare susceptibility differences between MS patients and healthy controls.

Main Methods:

• Prospective study of 600 MS patients and 250 healthy controls using 3.0-T MRI.
• Quantitative susceptibility mapping (QSM) to measure magnetic susceptibility in deep gray matter.
• Region of interest and voxelwise analyses, controlling for age and sex, to assess associations with clinical outcomes.

Main Results:

• MS patients showed lower thalamic susceptibility and higher basal ganglia susceptibility compared to controls.
• Lower thalamic susceptibility correlated with longer disease duration, greater disability, and progressive MS.
• Higher globus pallidus susceptibility was associated with increased disability, independent of atrophy.

Conclusions:

• Altered deep gray matter iron, detected by QSM, is associated with MS progression and disability.
• These findings suggest iron deposition plays a role in MS pathogenesis and clinical outcomes.
• QSM provides valuable insights into MS pathophysiology beyond tissue atrophy.