The effect of natalizumab on cognitive function in patients with relapsing-remitting multiple sclerosis: preliminary results of a 1-year follow-up study.

The objective of the study was to assess the natalizumab effect on the course of cognitive impairment in patients with relapsing-remitting multiple sclerosis (MS). Patients with active relapsing-remitting MS (n = 17) were treated with natalizumab for 1 year. The quasi control group included patients (n = 7) with clinically stable MS. Assessment of disease course [expanded disability status scale (EDSS); number of relapses] and neuropsychological impairment [Wisconsin card sorting test (WCST); controlled oral word associations; verbal/non-verbal memory tests; paced auditory serial addition test] was conducted at baseline and after 1 year. Natalizumab-treated patients experienced significantly fewer relapses compared with the previous year (P < 0.05). At 1-year follow-up, EDSS score was unchanged and neuropsychological assessments of memory/executive functions showed a significant improvement in natalizumab-treated patients (all P < 0.05). No changes were observed in the quasi control group. This preliminary study suggests that natalizumab could be effective in ameliorating cognitive functions in patients with active relapsing-remitting MS, over 1-year follow-up.