Serum neurofilament light chains in MS: Association with the Timed Up and Go

OBJECTIVE: This cross-sectional study aims to assess the association between neuroaxonal damage assessed by serum neurofilament light chain (sNfL) and the Timed Up and Go (TUG)—a reliable and rapid measure of global neurologic disability—in patients with MS. METHODS: A total of 41 consecutive patients with MS (38.0 ± 10.4 years; 57% women) with low level of disability (Expanded Disability Status Scale [EDSS] score 0–3) (EDSS score 1.0, interquartile range [IQR] 0.0–2.0) were included in this study. The TUG and sNfL were measured in a 6-month interval, together with a comprehensive neuropsychological and quantitative gait evaluation. The association of sNfL (dependant variable) with TUG, and other gait, cognitive, and behavioral measures (independent variables) were evaluated with multiple linear regressions adjusted for age, sex, and EDSS score. RESULTS: The sNfL concentration was 23.51 pg/mL (IQR 16.51–32.21 pg/mL), and the mean TUG was 9.27 ± 1.70 seconds. Only the TUG was associated with sNfL (β = 0.021; 95% CI 0.003–0.037; p = 0.022) (after adjusting for age, sex, and EDSS score), whereas this was not the case for gait and neuropsychological measures. CONCLUSIONS: The TUG—an easy and unexpansive measure of disability—is associated with the degree of neuroaxonal damage, as measured by sNfL, in patients with MS with low level of disability. These findings confirm the validity of the TUG as a reliable bedside measure of global neurologic disability as a result of neuroaxonal damage.