Upper cervical cord atrophy is independent of cervical cord lesion volume in early multiple sclerosis: A two-year longitudinal study

Background: Upper cervical cord atrophy and lesions have been shown to be associated with disease and disability progression already in early relapsing-remitting multiple sclerosis (RRMS). However, their longitudinal relationship remains unclear. Objective: To investigate the cross-sectional and longitudinal relation between focal T2 cervical cord lesion volume (CCLV) and regional and global mean upper cervical cord area (UCCA), and their relations with disability. Methods: Over a two-year interval, subjects with RRMS (n = 36) and healthy controls (HC, n = 16) underwent annual clinical and MRI examinations. UCCA and CCLV were obtained from Cl through C4 level. Linear mixed model analysis was performed to investigate the relation between UCCA, CCLV, and disability over time. Results: UCCA at baseline was significantly lower in RRMS subjects compared to HCs = 0.003), but did not decrease faster over time (p >= 0.144). UCCA and CCLV were independent of each other at any of the time points or cervical levels, and over time. Lower baseline UCCA, but not CCLV, was related to worsening of both upper and lower extremities function over time. Conclusion: UCCA and CCLV are independent from each other, both cross-sectionally and longitudinally, in early MS. Lower UCCA, but not CCLV, was related to increasing disability over time.