BACKGROUND: Cognitive decline has been recognised as a frequent symptom in multiple sclerosis (MS). Cholinesterase inhibitors (ChEIs) are employed for the treatment of Alzheimer’s disease, but there is some evidence that ChEIs might also be effective in MS patients with cognitive deficits, particularly deficits of memory function.
OBJECTIVE: The aim of this study was to evaluate efficacy on memory function and safety of the ChEI rivastigmine in MS patients with cognitive deficits as measured by the change from baseline of the total recall score of the selective reminding test (SRT) after 16 weeks of treatment.
METHODS: Efficacy and safety of rivastigmine were analysed in a 16-week, multicentre, double-blind, randomised, placebo-controlled study, followed by an optional one-year open-label treatment phase. Effects of rivastigmine and placebo were compared by an analysis of covariance.
RESULTS: In total, 86 patients were enrolled. Patients who received rivastigmine (n = 43) showed a non-significant increase in total recall score (sum of all words immediately recalled over all six trials) over placebo (n = 38) after 16 weeks of treatment (p = 0.2576). Other outcome measures provided no evidence supporting benefits of rivastigmine. Treatment with rivastigmine was well tolerated.
CONCLUSIONS: With the results of this study, the need for an effective therapy in cognitively impaired MS patients is still required. Thus, intensive and continued clinical research is required to explore therapeutic options for cognitive deficits in MS patients.
This study failed to show any evidence of benefit with Rivastigmine a non-significant increase is not good enough, it is not significant and this is no effect of drug. However, this was a small study, was it too small? Underpowered studies do us little favours because they usually mean nothing conclusive and trials need to be done again, wasting time and resource. Furthermore because of failure, interest in a repeat trial is not there. They should be done once properly and get definitive answers.