The Effects of Aerobic Exercise on Cognitive Function in Patients Post Stroke

Background: Approximately 795 000 people have a stroke each year,of those 470 000 survive with mild to severe cognitive dysfunction.Stroke is the second leading cause of cognitive impairment and dementia in the country and the leading cause of disability.Only 1% of the brain has to be effected by stroke to lead to cognitive impairment.Because of the large impact stroke has on cognitive function it is critical to find cost effective ways to improve cognitive function in surviving stroke patients. Aerobic exercise has been shown to cause vascular changes with enhancement of cerebral blood flow, increase in neurotrophin factors and change the regulation of neurotransmitter synthesis in healthy adults.The purpose of this systematic review is to determine if stroke patients have the same improvement in cognitive function with aerobic exercise as healthy adults. Method: An exhaustive literature search was conducted in Medline-OVID, CINAHL and Web of Science using the search terms stroke, cognition and aerobic exercise. Scientific terms that were synonymous to these three terms, including, cognitive function, exercise and cerebral vascular accident were searched to prevent any relevant research articles to be overlooked. Articles were limited to English only and conducted on humans. Excluded were articles that included children, subjects with prior cognitive delay, dementia, psychiatric disorders and systematic reviews. There were no exclusions using GRADE criteria. Results: Four articles met the inclusion and exclusion criteria for the systematic review. One study was a randomized control trial, one was a randomized crossover trial and two were quasi-experimental design. Three of the four articles found a positive correlation between aerobic exercise and cognitive function, while one study was unable to reveal an association between the two variables. All studies found a positive correlation with motor function and aerobic exercise. Conclusion: This systematic review determined that there is a correlation between improved cognitive function and aerobic exercise. There were many limitations to each study and future research is warranted due to the impact that improved cognitive function will have on stroke patients.