Iron deposition in multiple sclerosis: overall load or distribution alteration?

Area of Science:

• Neuroimaging
• Neurology
• Biomedical Engineering

Background:

• Abnormal iron deposition is observed in specific brain regions in multiple sclerosis (MS).
• Previous studies have not determined if the overall brain iron quantity is altered in MS.
• This study investigates whether aberrant iron deposition in MS is due to global load or regional distribution.

Purpose of the Study:

• To determine if multiple sclerosis involves an altered global brain iron load or a regional distribution of iron.
• To compare global and regional brain iron concentrations between MS patients and healthy controls.

Main Methods:

• Quantitative susceptibility mapping from 3-T MRI scans of 30 MS patients and 15 controls.
• Analysis by neuroradiologists, a radiology software engineer, and neurologists.
• Assessment of global brain iron load and regional iron concentrations in lesions, white matter, thalami, and basal ganglia.

Main Results:

• Global brain iron load was comparable between MS patients and controls after volume adjustment (p = 0.660).
• Regional iron concentrations were significantly different in MS patients compared to controls (p ≤ 0.031).
• Regional iron concentrations, but not global load, correlated with age, disease duration, and disability grade in MS patients (p ≤ 0.039).

Conclusions:

• Aberrant iron deposition in multiple sclerosis is primarily a problem of regional distribution.
• The overall global brain iron load does not appear to be significantly altered in MS.