Factors associated with learning and memory rehabilitation efficacy in MS: preliminary data of a sub-analysis of the MEMREHAB trial
Objectives: This study explored the influence of disease duration and motor disability on benefit from treatment with the mSMT.
Methods: This sub-analysis of the double-blind, placebo-controlled, randomized clinical trial included 56 participants. Participants were randomly assigned to the treatment (n= 29) or placebo-control group (n= 27). The present study represents a post-hoc analysis to examine the role of disease duration and motor disability on treatment efficacy. At baseline and immediate follow-up all participants performed the California Verbal Learning Test (CVLT). The mSMT is a 10 session (5 weeks) behavioral intervention that teaches context and imagery to facilitate learning and memory.
Results: The treatment group showed a significantly improved CVLT learning slope (1-4) relative to the placebo-control group post-treatment (F (1, 55) = 4.53, p=.04), after co-varying disease duration and motor disability. Disease duration (F (1, 55) = .87, ns) and motor disability (F (1, 55) = 1.32, ns) were not significant predictors of benefit from mSMT treatment, beyond group assignment. Post-hoc analysis showed no significant correlations between change score on CVLT learning slope (1-4) and disease duration (r = -.12, ns), or motor disability (r= -.2, ns).
Conclusions: This study suggest that individuals with MS can benefit from learning and memory rehabilitation programs independent of motor disability or disease duration. Prior research has shown that disease progression is associated with decline in cognitive function and higher levels of brain pathology, however disease duration did not impact the efficacy of mSMT on learning and memory in MS in the current study. Further studies are needed to understand the interaction between degree of brain pathology and the efficacy of mSMT.