Iron Rims in Patients With Multiple Sclerosis as Neurodegenerative Marker? A 7-Tesla Magnetic Resonance Study

Area of Science:

• Neuroscience
• Radiology
• Biomarkers

Background:

• Multiple sclerosis (MS) is a central nervous system disease causing demyelination and neurodegeneration, leading to physical and neuropsychological deficits.
• Iron rim lesions (IRLs) in MS are associated with severe tissue destruction and clinical disability accumulation.
• Understanding the role of IRLs and associated biomarkers is crucial for tracking MS progression.

Purpose of the Study:

• To assess subcortical atrophy and ventricular enlargement using 7 Tesla (T) MRI in MS patients with and without IRLs.
• To evaluate serum neurofilament light chain (sNfL) levels as a biomarker for neurodegeneration in MS patients with IRLs.
• To correlate imaging and biomarker data with neuropsychological performance in MS patients with and without IRLs.

Main Methods:

• Utilized 7-T MRI (SWI, FLAIR, MP2RAGE) and 3D Segmentation Software for volumetric analysis of lesions, subcortical structures, and ventricles in 29 MS patients.
• Measured serum neurofilament light chain (sNfL) concentrations using the Simoa SR-X Analyzer.
• Conducted neurological and neuropsychological examinations, including the Symbol Digit Modalities Test (SDMT), to assess clinical and cognitive status.

Main Results:

• Patients with IRLs had higher FLAIR lesion counts and greater MP2Rage lesion volume.
• IRL patients exhibited smaller thalamic volumes and enlarged lateral ventricles over 3 years.
• Higher sNfL concentrations were observed in IRL patients and correlated with poorer SDMT performance, irrespective of IRL presence.

Conclusions:

• IRL patients demonstrate increased lesion burden, thalamic atrophy, and elevated sNfL levels compared to non-IRL patients.
• The combination of IRL imaging and sNfL biomarkers may indicate neurodegenerative processes in MS.
• Preliminary findings support the destructive nature of IRLs in MS pathogenesis and progression.