Cognitive deficits are a common manifestation in multiple sclerosis (MS) and have a wide effect on the patient's quality of life. Alleviation of the harmful effects caused by these deficits should be a major goal of MS research and practice.
The aim of this review was to evaluate the effects of neuropsychological/cognitive rehabilitation in MS by conducting a systematic review.
A systematic literature search was carried out on reports drawn from Cochrane MS Group Specialised Register (To October 2010), Evidence-based medicine (EBM) reviews (To September 2010), MEDLINE (January 1950 to September 2010), EMBASE (1974 to September 2010), PsycINFO (January 1806 to September 2010), WEB OF SCIENCE (WOS) (January 1986 to September 2010), CINAHL (1982 to September 2010), and identified from the references in these reports.
Randomised Controlled Trials (RCTs) and quasi-randomised trials evaluating the effects of neuropsychological rehabilitation in MS compared to other interventions or no intervention at all and employing neuropsychological rehabilitation methods and outcome measures were included.
Data collection and analysis
Two review authors individually judged the relevance, risk of bias, and content of the included studies. Results were combined quantitatively with meta-analyses according to the intervention type: 1) Cognitive training and 2) Cognitive training combined with other neuropsychological rehabilitation methods. In addition, narrative presentation was used in reporting the results of those studies which were inappropriate to be included in the meta-analysis.
Fourteen studies (770 MS patients) fulfilled the inclusion criteria. On the basis of these studies, low level evidence was found that neuropsychological rehabilitation reduces cognitive symptoms in MS. Cognitive training was found to improve memory span (standardised mean difference 0.54 (95% confidence interval 0.2 to 0.88, P = 0.002)), working memory (standardised mean difference 0.33 (95% confidence interval 0.09 to 0.57, P = 0.006)), and immediate visual memory (standardised mean difference 0.32 (95% confidence interval 0.04 to 0.6, P = 0.02)). There was no evidence of an effect of cognitive training combined with other neuropsychological rehabilitation methods on cognitive or emotional functions. The overall quality as well as the comparability of the included studies were relatively low due to methodological limitations and heterogeneity of outcome measures. Although most of the pooled results in the meta-analyses yielded no significant findings, twelve of the fourteen studies showed some evidence of positive effects when the studies were individually analysed.
The review indicates low level evidence for the positive effects of neuropsychological rehabilitation in MS. Interventions included in the review were heterogeneous. Consequently, clinical inferences can basically be drawn from single studies. Therefore, new trials may change the strength and direction of the evidence. To further strengthen the evidence, well-designed high quality studies are needed. In this systematic review, recommendations are given for improving the quality of future studies on the effects of neuropsychological rehabilitation in MS.