Structural MRI Corrrelates of Cognitive Impairment in Patients with Multiple Sclerosis: A Multi Center Study (S33.002)

OBJECTIVE: To apply a voxel-wise analysis to high-resolution T1-weighted and diffusion tensor (DT)-MRI scans to assess the structural correlates of cognitive dysfunction in multiple sclerosis (MS) patients and their validity in a multicenter setting. BACKGROUND: The assessment of regional brain gray matter (GM) and white matter (WM) damage using voxel-wise approaches has provided valuable correlates of clinical disability and cognitive impairment in MS. DESIGN/METHODS: Brain dual-echo, 3DT1-weighted, and DT-MRI sequences were collected from 62 relapsing-remitting MS patients and 65 healthy controls (HC) from seven European centers. The Expanded Disability Status Scale score, RAO’s neuropsychological battery and Wisconsin Card Sorting Test were assessed. Patients with 蠅2 abnormal neuropsychological tests were considered cognitively impaired (CI). The distribution of GM and WM atrophy and microstructural WM damage were assessed using voxel-wise approaches. RESULTS: No groupxcenter interaction was found for T2-hyperintense, T1-hypointense lesion volume, GM and WM volumes, whereas significant interaction for GM and WM DT-MRI metrics was found. Twenty-three (37%) MS patients were classified as CI. Compared to cognitively preserved (CP), CI patients had higher T2 and T1 lesion volume, and lower volumes of the whole brain, WM, GM and deep GM nuclei. From DT-MRI analysis, intrinsic damage within T2 lesions, but not damage to the WM and GM, was more severe in CI vs CP patients. Using voxel-based morphometry, compared to CP patients and HC, CI patients had atrophy of the thalami, hippocampi, several fronto-parietal GM regions and the posterior corpus callosum (CC). At the level of the CC, CI patients also had lower fractional anisotropy. CONCLUSIONS: The application of voxel-wise methods to define the regional distribution of brain damage in a multicenter setting in MS patients is feasible and contributes to better characterize disease manifestations. Regional atrophy evaluation seems to be less affected than DT-MRI evaluation by a multicenter set-up. Study Supported by: