Poster Abstract #14: Magnetic Resonance Disease Severity Scale (MRDSS) Predicts Clinical Progression in Multiple Sclerosis

Abstract

Objective Combine MRI measures of disease severity into a composite score in patients with multiple sclerosis (MS). Background Brain MRI lesion and atrophy measures assessed individually have fairly weak ability to predict clinical progression in MS. Methods In the Comprehensive Longitudinal Investigation of MS at Brigham, we studied 103 patients [age (mean ± SD) 42.7 ± 9.1 years, disease duration 14.1 ± 9.2 years, Expanded Disability Status Scale (EDSS) score 3.3 ± 2.2, 60% (n = 62) relapsing–remitting (RR), 32% (n = 33) secondary progressive (SP), and 8% (n = 8) primary progressive]. Brain MRI measures included baseline T2 hyperintense (T2LV) and T1 hypointense (T1LV) lesion volume, and brain parenchymal fraction (BPF), a marker of global atrophy. The ratio of T1LV to T2LV assessed lesion severity. A Magnetic Resonance Disease Severity Scale (MRDSS) score, on a continuous scale from 0 to 10, was derived for each patient using T2LV, BPF, and T1/T2 ratio. Results MRDSS score averaged 5.1 ± 2.6. Baseline MRI and EDSS correlations were moderate for BPF, T1/T2, and MRDSS and weak for T2LV. MRDSS showed a larger effect size than any of the individual MRI components in distinguishing RR from SP patients. Models containing either T2LV or MRDSS were significantly associated with EDSS disability progression during the 3.2 ± 0.3 year observation period, when adjusting for baseline EDSS score. Conclusions These results show that combining brain MRI lesion and atrophy measures can predict clinical progression in patients with MS and provide the basis to develop an MRI-based continuous scale as a marker of MS disease severity.