多発性硬化症で低および高障害を持つ人々における軸索およびミエリン微細構造の脳室周囲勾配の存在

MS imaging studies have demonstrated an ependymal "surface-in" distribution of white matter damage. The origin of this effect and how it impacts myelinated axons in people with MS (PwMS) is poorly understood.

To investigate (1) whether there is clear evidence of tract-wise, periventricular damage, based on fractional anisotropy, mean diffusivity, axonal water fraction (AWF) and myelin volume fraction (MVF), in PwMS, (2) if such tissue damage is associated with T₁-"black-hole" (T₁-BH) and/or non-BH lesions, and (3) if periventricular quantitative MRI abnormalities are correlated with lateral ventricle (LV) and choroid plexus (CP) enlargement.

We applied structural, MT-weighted, and multi-shell diffusion MRI in healthy controls and PwMS to quantify periventricular gradient damage to axons and myelin. We also evaluated the correlation between such gradient damage and both non-BH and T₁-BH lesion loads, and brain volume changes.

Clear periventricular gradients exist in both AWF and MVF measures in the Association and Projection Tracts. They are strongly correlated with T₁-BH lesion load, and with LV and CP enlargement in PwMS with EDSS > 2.

Tract-specific, periventricular gradients in PwMS exist prominently in AWF and MVF, are strongly associated with T₁-BH lesion loads, and correlate with LV and CP enlargement.