Pharmacologic treatment for memory disorder in multiple sclerosis.

BACKGROUND:

Memory disorder is one of the most frequent cognitive impairment and has a great negative impact on the quality of life in patients with multiple sclerosis (MS). A few pharmacologic agents appear to be effective to memory disorder in patients with MS in some existing randomised controlled trials.

OBJECTIVES:

To assess the absolute and comparative efficacy, tolerability and safety of pharmacologic treatments for memory disorder in adult patients with MS.

SEARCH STRATEGY:

We searched the Cochrane Multiple Sclerosis Group's Trials Register (17 January 2011), PsycINFO (January 1980 - April Week 4 2011) and CBMdisc (January 1978 - 6 April 2011), and checked reference lists of identified articles, searched some relevant journals manually, registers of clinical trials and published abstracts of conference proceedings.

SELECTION CRITERIA:

All double-blind, randomized controlled parallel trials on pharmacologic treatment versus placebo treatment or no treatment or one or more pharmacologic treatments, without restrictions regarding dose, route of administration and frequency, administration duration≥12 weeks for memory disorder in adult patients with MS who display at least mild memory impairment at 0.5 standard deviations below age -and-sex-based normative data on a validated memory scale. Adequately randomized or quasi-randomized trials were included.

DATA COLLECTION AND ANALYSIS:

Two review authors independently assessed trial quality and extracted data. Disagreements were discussed and resolved by consensus among review authors. Principal investigators of included studies were contacted for additional data or confirmation.

MAIN RESULTS:

Four RCTs involving adult patients with all the types of MS and at least mild memory impairment were included, evaluating donepezil, Ginkgo biloba (GB), memantine and rivastigmine respectively vs placebo in treating memory disorder in MS.There were no serious adverse events in intervention groups.The quality of the included studies was overall low, some of important variables were not matched between groups at baseline, the samples of subjects were relatively small and the follow-up was short. Three RCTs which evaluate GB, memantine, rivastigmine respectively vs placebo are currently ongoing.

AUTHORS' CONCLUSIONS:

Until the results of ongoing studies are available, there is no convincing evidence to support pharmacologic intervention as an effective treatment for memory disorder in MS patients. However, donepezil, Ginkgo biloba, memantine and rivastigmine resulted to be safe and well tolerated as adverse events such as nausea, diarrhea, somnolence, and constipation were not frequent,  while no serious adverse effects were reported. Future high quality randomised controlled trials are needed.