Impact of Natalizumab Treatment on Fatigue, Mood, and Aspects of Cognition in Relapsing–Remitting Multiple Sclerosis

BACKGROUND/OBJECTIVE: Fatigue, cognitive, and affective disorders are relevant symptoms in multiple sclerosis (MS). The treatment with Natalizumab has a positive effect on physical disabilities in patients with relapsing–remitting MS (RRMS). Some studies describe improvements in cognition and fatigue over 1 year of treatment. Only little is known about longer treatment effects especially on fatigue, and also on cognition and mood. Therefore, the present retrospective open label observational study investigates the effect of Natalizumab on fatigue, attention, and depression over a treatment period of 2 years. METHODS: About 51 RRMS patients who were treated with Natalizumab (male = 11, female = 40; mean age: 33. 9 ± 9. 1 years) were included. The neuropsychological assessment consisted of different tests of attention (TAP: alertness, divided attention, flexibility, SDMT, PASAT), fatigue (WEIMuS, FSMC), and depression (CES-D). The assessments occurred immediately before the first administration of Natalizumab, after 1 and 2 years of treatment. RESULTS: Significant improvements were found in aspects of attention and depression from baseline to follow-up 1 [alertness: reaction time (RT) cued, p < 0.05; divided attention: visual RT, p < 0.05; SDMT: p = 0.05; CES-D: p < 0.05] and from baseline to follow-up 2 (divided attention: visual RT: p < 0.001; errors: p < 0.01, omissions: p < 0.05; flexibility: RT, p < 0.05; SDMT: p < 0.01; CES-D: p < 0.05). No significant changes were detected in fatigue, probably because of the small sample size, especially in the second year of treatment (WEIMuS: N = 16, FSMC: N = 8). CONCLUSION: The results show a positive effect of Natalizumab on attention in patients with RRMS, and for the first time, also in depression after 2 years of observation, and support the efficacy of the treatment over 2 years. More research is needed for fatigue.