Efficacy of exercise intervention programs on cognition in people suffering from multiple sclerosis, stroke and Parkinson's disease: A systematic review and meta-analysis of current evidence

BACKGROUND: Cognitive impairment is a well-established sequela of people suffering from neurological pathologies. OBJECTIVE: To examine the effects of exercise intervention programs on cognitive performance in participants suffering from stroke, multiple sclerosis and Parkinson's disease. METHODS: Four online databases (CINAHL, Cochrane Library, MEDLINE, PEDro) were comprehensively searched from their inception through December 2014. The search query was phrased as follows: In people suffering from MS, stroke or Parkinson's disease, do exercise intervention programs improve cognitive performance? RESULTS: Twelve controlled clinical trials met our inclusion criteria. Studies were classified according to three clinical subgroups: Parkinson's disease (n = 3), stroke (n = 1) and multiple sclerosis (n = 8). Eight studies employed an aerobic intervention program; one used an active exercise program based on virtual reality systems, three reports examined the effect of yoga and one compared the intervention program with sport climbing. Significant improvements in cognition were found in nine out of the twelve studies. Nevertheless, the total effect size was non-significant (0.18 (95% CI, -4.1, 3.8)) for changes in executive functions. CONCLUSION: Due to lack of commonality between measures of cognition, training sequences and intervention period, it remains unclear as to whether exercise training can be effective in improving the cognitive functions of neurological patients.