Objective: We aimed to investigate the influence of natalizumab (NTZ) treatment on multiple sclerosis course in patients with and without spinal involvement.
Methods: Annualized relapse rate (ARR), disability progression and occurrence of new brain and spinal T2 lesions (N2TL) in 68 spinal (S-P) versus 68 non-spinal matched patients (NS-P) were retrospectively collected and compared between before (2 years) and after NTZ treatment using multivariate regression models.
Results: Mean duration of NTZ treatment was 31.3 ± 16.3 months in S-P and 32.1 ± 15.1 months in N-SP (p = 0.56). The mean ARR after NTZ treatment was similarly reduced in both S-P (0.07 ± 0.19) and N-SP (0.07 ± 0.16) (p < 0.001 for both). Disability progression after NTZ start was similarly low in S-P and NS-P. However, when compared to before NTZ start, disability progression was significantly reduced in S-P (p = 0.017), but not in NS-P (p = 0.68). This was largely mediated by a higher disability progression before NTZ start in S-P than N-SP. The risk of developing N2TL during NTZ was not different between S-P and NS-P (p = 0.10).
Conclusions: NTZ similarly reduced the occurrence of relapses and NT2L in S-P and NS-P, whereas the effect on disability progression was particularly evident in the presence of spinal involvement. NTZ appears to be a treatment of high efficacy in both S-P and NS-P.
Keywords: multiple sclerosis; natalizumab; relapses; spinal cord.