Limbic system damage in MS: MRI assessment and correlations with clinical testing

Area of Science:

• Neuroimaging
• Neurology
• Biomarker Discovery

Background:

• Multiple Sclerosis (MS) is associated with limbic system volume loss.
• In vivo assessment of tissue microstructure integrity in MS remains underexplored.
• Limbic system dysfunction contributes to cognitive and physical impairment in MS.

Purpose of the Study:

• To quantitatively assess limbic system volume and tissue integrity in MS patients.
• To evaluate the association of these measures with cognitive and physical dysfunction.
• To introduce R2t* as a novel biomarker for MS-related tissue damage.

Main Methods:

• Utilized multi-gradient-echo MRI to calculate tissue-specific parameter R2t*.
• Separated R2t* from BOLD contributions and accounted for physiological artifacts.
• Measured normalized limbic system volumes from MPRAGE images in 80 MS patients and 31 healthy controls.

Main Results:

• MS patients exhibited lower R2t* and smaller normalized volumes in key limbic regions (hippocampus, amygdala) compared to controls.
• R2t* alterations correlated more broadly with clinical and neurocognitive scores than volume loss.
• R2t* proved more sensitive to limbic system tissue damage than atrophy measurements.

Conclusions:

• R2t* is a sensitive indicator of limbic system tissue integrity loss in MS.
• R2t* measurements offer a distinct and complementary biomarker to volumetric analysis in MS.
• This approach enhances the understanding and assessment of MS pathology and its functional consequences.