Memory improvement in multiple sclerosis after an extensive cognitive rehabilitation program in groups with a multicenter double-blind randomized trial

Objective: The aim of this study is to determine the effectiveness of an extended cognitive rehabilitation program in group's sessions in multiple sclerosis. Design: Double-blind multicenter randomized trial. Participants: People with multiple sclerosis of 18 to 60 years, Expanded Disability Status Scale <= 6.0, mild to moderate cognitive impairment. Interventions: They were randomized into cognitive rehabilitation program (ProCog-SEP) or in a placebo program. ProCog-SEP comprises 13 group's sessions over 6 months and includes psychoeducational advices and cognitive exercises. Placebo program included non-cognitive exercises. No strategy and no cognitive advice were provided. Main measures: The primary endpoint was the percentage of verbal memory learning measured by the Selective Reminding Test. A comprehensive neuropsychological assessment is carried out before and after interventions by a neuropsychologist blinded to intervention. Effectiveness of the ProCog-SEP versus Placebo has been verified using linear regression models. Results: In total, 128 participants were randomized and 110 were included in the study after planning session in groups; 101 completed this trial (77.2% females); mean age: 46.1 years (+/- 9.6); disease duration: 11.8 years (+/- 7.5). ProCog-SEP was more effective in increasing in learning index (9.21 (95% confidence interval (CI): 1.43, 16.99); p = 0.02) and in working memory on manipulation (0.63 (95% CI: 0.17, 1.09); p = 0.01), and updating capacities (-1.1 (95% CI: -2.13, -0.06); p = 0.04). No difference was observed for other neuropsychological outcomes. Regarding quality of life outcomes, no change was observed between the two groups. Conclusion: These findings suggest that ProCog-SEP could improve verbal learning abilities and working memory in people with multiple sclerosis. These improvements were observed with 13 group sessions over 6 months.