Related Experiment Video
Updated: Feb 13, 2026

Comprehensive Autopsy Program for Individuals with Multiple Sclerosis
Published on: July 19, 2019
Heterogeneous Deep Gray Matter Iron Deposition Patterns across Multiple Sclerosis Subgroups Defined by the
Jinlin Jiao1, Ruisi Gong1, Hao Zhang1
1Department of Radiology, The First Hospital of China Medical University, P.R. China.
None:
The clinico-radiological paradox in multiple sclerosis (MS) describes the disconnect between white matter lesion load and clinical disability. This study investigated the role of deep gray matter (DGM) iron deposition in this paradox, specifically regarding cognitive impairment. We classified 134 MS patients into subgroups based on T2-lesion volume (LV) and disability (EDSS): LL/LD, HL/LD, LL/HD, HL/HD, comparing them to 46 healthy controls (HCs). Using quantitative susceptibility mapping (QSM) and volumetric analysis, we assessed iron content and atrophy in DGM nuclei, alongside cognitive testing (MoCA, SDMT). Subgroups with high lesion burden (HL/LD, HL/HD) showed significantly increased iron and atrophy in the globus pallidus, putamen, and caudate versus HCs. A critical group-by-volume interaction on susceptibility was found in the putamen for HL/LD (β=-0.55) and HL/HD (β=-0.35) subgroups. Mediation analysis revealed that putamen volume mediates the effect of iron on cognition, with significant indirect effects on SDMT (β=-0.18) and MoCA (β=-0.14) across all patients. In the HL/HD subgroup, this pathway accounted for 45.8 % of iron's total effect on processing speed (SDMT). Our findings demonstrate heterogeneous DGM iron deposition and identify putaminal iron-induced atrophy as a key mechanistic pathway for cognitive deficits, offering a novel explanation for the paradox and a potential biomarker for cognitive risk stratification.
Related Concept Videos
Classifying Matter by Composition
According to its composition, the matter can be classified into two broad categories — pure substances and mixtures.
A pure substance is a form of matter that has a constant composition throughout with uniform properties. For example, any sample of sucrose has the same composition and same physical properties, such as melting point, color, and sweetness, regardless of the source from which it is isolated.
A mixture is composed of two or...
¹H NMR Signal Multiplicity: Splitting Patterns
Classifying Matter by State
The Atomic Theory of Matter
Physical and Chemical Properties of Matter
Phase Transitions: Sublimation and Deposition

