Exercise Promotes Cognitive Recovery After Stroke
HOUSTON, Texas — Structured physical activity can improve brain function after stroke, a meta-analytic review of relevant studies shows.
"We found that a program as short as 12 weeks is effective at improving cognition, and even patients with chronic stroke can experience improvement in their cognition with an exercise intervention," lead author Lauren E. Oberlin, a graduate student at the University of Pittsburgh in Pennsylvania, said in a statement.
Oberlin presented her research at a briefing here at the International Stroke Conference (ISC) 2017.
She noted that cognitive deficits after stroke are prevalent, affecting 30% to 85% of stroke survivors, and persistent. Post-stroke cognitive deficits increase the risk for long-term disability, functional decline, dependent living, and death.
Structured physical activity has been shown to enhance cognitive function in other at-risk populations, including healthy aging adults and those with multiple sclerosis, dementia, and Parkinson's disease.
Never Too Late to Start
In their meta-analysis, Oberlin and colleagues synthesized data from 736 stroke patients enrolled in 14 trials testing various types of physical activity (aerobic, strength training, or a combination vs control) on neurocognitive function.
Physical activity training had a positive moderate effect size on global cognition (Hedges' g = 0.56; 95% confidence interval [CI], 0.41 - 0.70; P < .001). A mixed-effects analysis indicated that physical activity training led to significantly greater cognitive gains relative to controls (P = .002).
Specifically, physical activity training had positive moderate effects on attention and processing speed (Hedges' g = 0.31; 95% CI, 0.10 - 0.51; P = .004). "We didn't find significant effects with executive function or working memory; however, this analysis was done with only 5 studies so interpretation is limited," Oberlin said.
Physical activity training had benefits on cognition regardless of the length of training. Programs lasting greater than 3 months, as well as those lasting from 1 to 3 months, led to improvements in cognitive performance.
Cognitive improvements were seen in patients who started an exercise program within 3 months of stroke and in those who started much later in the chronic stroke phase. "What's really striking," said Oberlin, "is that a total of 10 studies looked at exercise effects in chronic stroke, and across those 10 studies individuals started exercising on average more than 2 and a half years after stroke and still experienced cognitive improvement."
Combining aerobic exercise with stretching, toning, and balance training resulted in the largest cognitive gains, she noted.
"Physical activity shouldn't be overlooked as a way to promote cognitive recovery after a stroke," said Oberlin. "Integrating aerobic training into rehabilitation is very important, and for patients with mobility limitations, exercise can be modified so they can still experience increases in their fitness levels," she noted. "This has substantial effects on quality of life and functional improvement."
Reached for comment, Anand Patel, MBBS, vascular neurologist at Northwell Health's Neuroscience Institute in Manhasset, New York, who wasn't involved in the study, said, "We all know there is a cognitive impact after the stroke and exercise is one way we can improve cognition after stroke without any significant side effects.
"This analysis showed definite improvement in cognition with exercise, even months after the stroke. This was a meta-analysis, not a randomized controlled trial, so we can say there is an association but the causation is still lacking," said Dr Patel.
"We like stroke patients to do exercises as soon as possible. Even in the hospital before discharge to rehabilitation, we almost always ask the patient to do some kind of exercise to get started," Dr Patel added.
The study had no funding, and the authors have disclosed no relevant financial relationships.
International Stroke Conference (ISC) 2017. Abstract 96. Presented February 22, 2017.
SOURCE: Medscape, February 28, 2017