A Cochrane review [Abstract] 1 included 7 RCTs with 625 participants. They mostly had relapsing-remitting, secondary-progressive or primary-progressive MS. The efficacy of donepezil (2 trials, n=189), ginkgo biloba (2 trials, n=164), memantine (one trial, n=126) and rivastigmine (2 trials, n=146) vs. placebo was assessed in improving memory performance with diverse assessment scales. Due to methodological limitations in studies, a meta-analysis was not possible. A subgroup analysis for donepezil vs. placebo (treatment duration 24 weeks, 2 trials, n=189) showed no treatment effects on total recall on the Selective Reminding Test (MD 1.68, 95% CI -2.21 to 5.58), total correct scores on the 10/36 Spatial Recall Test (MD -0.93, 95% CI -3.18 to 1.32), the Symbol Digit Modalities Test (MD -1.27; 95% CI -3.15 to 0.61) and the Paced Auditory Serial Addition Test (2+3 sec) (MD 2.23, 95% CI -1.87 to 6.33). Concerning safety in the same trials, the main adverse events were diarrhoea (RR 3.88, 95% CI 1.66 to 9.05), nausea (RR 1.71; 95% CI 0.93 to 3.18) and abnormal dreams (RR 2.91; 95% CI 1.38 to 6.14). For other trials, assessed separately, no significant differences were found for the memory parameters evaluated with any of the medications. No serious adverse events were attributed to the treatments in all experimental groups.
Comment: The quality of evidence is downgraded by study quality (short follow-up time), inconsistency (heterogeneity in patients, interventions and outcomes), indirectness (differences in studied patients) and imprecise results (limited study size for each comparison).
Primary/Secondary Keywords