Radiologically Isolated Syndrome Carries a Multiple Sclerosis–Like Patient-Reported Burden: Disease-Specific Quality of Life Comparable to Relapsing–Remitting Multiple Sclerosis

Background: Radiologically isolated syndrome (RIS) is defined by MRI findings suggestive of multiple sclerosis (MS) in the absence of prior clinical demyelinating events. We aimed to compare health-related quality of life (HRQoL) between RIS and relapsing–remitting MS (RRMS) after adjusting for fatigue, cognition, and psychological distress, and to contextualize generic HRQoL relative to healthy controls. Methods: Data from 30 RIS, 29 RRMS, and 30 healthy controls were analyzed. MS-specific HRQoL (patients only) was assessed with the Functional Assessment of Multiple Sclerosis (FAMS), and generic HRQoL (all participants) was assessed with the EuroQol-5D (EQ-5D) visual analogue scale and utility index. Multivariable linear regression with robust (HC3) standard errors adjusted for demographics, fatigue impact, cognitive performance, and psychological distress. Results: FAMS totals were similar in RIS vs RRMS (median 167.50 vs 164.0; p=0.694) and remained non-different after adjustment (β=−2.37, 95% CI −10.18 to 5.44; p=0.544). EQ-5D outcomes showed an unadjusted gradient across groups, but adjusted differences relative to RIS were not statistically significant. Greater fatigue impact was associated with poorer HRQoL across all models (all p < 0.001). Psychological distress was associated with lower FAMS (β = -14.53; p < 0.001) but not with EQ-5D outcomes. Conclusion: HRQoL in RIS was comparable to RRMS; fatigue impact was the most consistent correlate of poorer HRQoL.