Dynamic disability measures decrease the clinico-radiological gap in people with severely affected multiple sclerosis

Background Expanded Disability Status Scale (EDSS) is limited when utilized in highly disabled people with multiple sclerosis (pwMS). Objetive To explore the relationship between disability measures and MRI outcomes in severely-affected pwMS. Methods PwMS recruited from The Boston Home (TBH), a specialized residential facility for severly-affected pwMS and University at Buffalo (UB) MS Center were assessed using EDSS, MS Severity Scale, age-related MSS, Scripps Neurological Rating Scale (SNRS) and Combinatorial Weight-Adjusted Disability Score (CombiWISE). In all scores except SNRS, higher score indicates greater disability. MRI measures of T1, T2-lesion volume (LV), whole brain, gray matter, medulla oblongata and thalamic volumes (WBV, GMV, MOV, TV) and thalamic dysconnectivity were obtained. Results Greatest disability differences between the TBH and UB pwMS were in SNRS (24.4 vs 71.9, p<0.001, Cohen's d=4.05) and CombiWISE (82.3 vs. 38.9, p<0.001, Cohen's d=4.02). In combined analysis of all pwMS, worse SNRS scores were correlated with worse MRI pathology in 8 out of 9 outcomes. EDSS only with 3 measures (GMV, MOV and TV). In severely-affected pwMS, SNRS was associated with T1-LV, T2-LV and WBV (not surviving false discovery rate (FDR) correction for multiple comparisons) whereas EDSS did not. Conclusion Granular and dynamic disability measures may bridge the clinico-radiologcal gap present in severely affected pwMS.