Cortical/subcortical disease burden and cognitive impairment in patients with multiple sclerosis

BACKGROUND AND PURPOSE: We assessed whether the extent of macro- and microscopic disease in the cortical and subcortical brain tissue, as revealed by MR and magnetization transfer (MT) imaging, correlates with cognitive dysfunction in patients with multiple sclerosis (MS). METHODS: Dual-echo rapid acquisition with relaxation enhancement (RARE), fast fluid-attenuated inversion recovery (fast-FLAIR), T1-weighted, and MT MR images of the brain were obtained from 16 MS patients with cognitive impairment and from six without. Impaired and unimpaired patients were similar across demographic and other disease-related variables. Total and cortical/subcortical lesion loads were assessed using RARE, fast-FLAIR, and T1-weighted sequences. In each patient, cortical/subcortical disease was also assessed by means of MT ratio (MTR) histographic analysis. RESULTS: All the impaired patients had multiple hyperintense lesions in the cortical/sub-cortical regions on both RARE and fast-FLAIR images; two unimpaired patients had such lesions on the RARE images and four had them on the fast-FLAIR images. Total and cortical/ subcortical RARE/fast-FLAIR hyperintense and T1 hypointense lesion loads were significantl