Hippocampal and Deep Gray Matter Nuclei Atrophy Is Relevant for Explaining Cognitive Impairment in MS: A Multicenter...

Area of Science:

• Neuroimaging
• Neurology
• Radiology

Background:

• Structural magnetic resonance imaging (MR) correlates of cognitive impairment in multiple sclerosis (MS) remain debated.
• Understanding these correlates is crucial for managing MS-related cognitive dysfunction.

Purpose of the Study:

• To identify MR imaging variables most closely associated with cognitive dysfunction in MS.
• To assess lesional and atrophy measures of white matter and gray matter involvement.

Main Methods:

• Acquired brain MR scans (dual-echo, 3D T1-weighted, double inversion recovery) at 3T from 62 MS patients and 65 controls.
• Identified focal white matter (WM) and cortical lesions; obtained volumetric measures of WM, cortical gray matter (GM), hippocampus, and deep GM nuclei.
• Used age- and site-adjusted models and multivariate analysis to associate MR imaging variables with cognitive scores and disability.

Main Results:

• 38% of MS patients were cognitively impaired.
• Cognitively impaired MS patients showed higher T2 and T1 lesion volumes and a trend toward more cortical lesions compared to cognitively preserved patients.
• Significant atrophy in the brain, cortical GM, hippocampus, deep GM nuclei, and WM was observed in cognitively impaired MS patients.

Conclusions:

• Hippocampal and deep GM nuclei atrophy are key factors associated with cognitive impairment in MS.
• WM atrophy is the strongest predictor of disability in MS.
• These MR imaging measures show potential for multicenter application with cognition as a clinical outcome.