Increased periventricular thalamic damage gradient in multiple sclerosis detected by quantitative gradient echo MRI.

Objective: Thalamic tissue damage in multiple sclerosis (MS) follows a 'surface-in' gradient from the ventricular surface. The clinical consequences of this gradient are not completely understood. Using quantitative gradient-recalled echo (qGRE) MRI, we evaluated a periventricular thalamic gradient of tissue integrity in MS and its relationship with clinical variables.
Methods: Structural and qGRE MRI scans were acquired for a cohort of MS patients and healthy controls (HC). qGRE-derived R2t* values were used as a measure of tissue integrity. Thalamic segmentations were divided into 1-mm concentric bands radiating from the ventricular surface, excluding the CSF-adjacent band. Median R2t* values within these bands were used to calculate the periventricular thalamic gradient.
Results: We included 44 MS patients and 17 HC. R2t* increased slightly with distance from the ventricular surface in HC. MS patients had a steeper periventricular thalamic gradient compared to HC (mean slope 0.55 vs. 0.36; p < 0.001), which correlated with longer disease duration (β = 0.001 /year; p = 0.027) and higher Expanded Disability Status Scale (EDSS) score (β = 0.07 /EDSS point; p = 0.019). Left and right thalamus were symmetrically affected.
Conclusions: We detected an increased thalamic gradient in MS in vivo using qGRE MRI, which correlated with disease duration and greater clinical disability. These findings further support the 'surface-in' pathology hypothesis in MS and suggest a CSF-mediated process given symmetric bi-thalamic involvement.
Competing Interests: Declaration of competing interest JRC has received grant support from the National MS Society and consulting honoraria from EMD Serono, Genentech, Janssen Pharmaceuticals, and Novartis. AHC has received consulting honoraria from Biogen, Bristol Myers Squibb, EMD Serono, and Genentech/F. Hoffman-La Roche, Horizon, Janssen, Novartis, Octave, and TG Therapeutics. MRB has received consulting honoraria from Bristol Myers Squibb, EMD Serono, Novartis, and TG Therapeutics.
(Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)