The Surface-In Effect: Multiple Sclerosis MRI Imaging Maps the Path of Decay

Is there a geometric logic to neurodegeneration? We often view lesions as scattered buckshot, random hits across the white matter. Yet, a closer look suggests a more insidious, directional force at work. New research investigates the "surface-in" distribution of damage, asking if the fluid-filled centres of the brain are the starting point for a creeping decay.

New clarity from Multiple Sclerosis MRI imaging

The investigators applied multi-shell diffusion techniques to map the health of axons and myelin. They were not merely counting spots; they measured the slope of damage. The data indicates clear periventricular gradients in both Axonal Water Fraction (AWF) and Myelin Volume Fraction (MVF). Simply put, the tissue closest to the ventricles suffers the most, with health improving as one moves deeper into the parenchyma.

This is not a uniform effect. The study identified these gradients specifically in the Association and Projection tracts. Notably, this pattern aligns with T₁ "black holes"—areas of permanent tissue destruction—rather than simple inflammatory lesions. It suggests that proximity to the ventricles is a liability.

The findings also highlight a correlation with the enlargement of the lateral ventricles and the choroid plexus, particularly in patients with higher disability scores. While the scan measures structural changes, the spatial association implies a pathogenic link. Factors within the cerebrospinal fluid or the choroid plexus may be diffusing outward, eroding the white matter from the inside edge.