Exercise can significantly improve brain function after stroke

American Stroke Association Meeting Report - Session A14 - Abstract 96

February 22, 2017

Science Daily/American Heart Association

Structured physical activity training after a stroke effectively improves brain function. Training that lasts as little as 12 weeks can be an effective treatment to limit cognitive decline following a stroke. Exercise can improve brain function in chronic stroke patients.

Stroke is the fifth leading cause of death in the United States, and the leading cause of long-term disability. Studies estimate that up to 85 percent of people who suffer a stroke will have cognitive impairments, including deficits in executive function, attention and working memory. Because there are no drugs to improve cognitive function, physical activity -- such as physical therapy, aerobic and strength training -- has become a low-cost intervention to treat cognitive deficits in stroke survivors.

In a meta-analysis of 13 intervention trials that included 735 participants, researchers analyzed the effects of various types of physical activity on cognitive function among stroke survivors. They found that structured physical activity training significantly improved cognitive deficits regardless of the length of the rehabilitation program (i.e., training longer than 3 months as well as from 1 to 3 months led to improvements in cognitive performance).

The researchers also found that cognitive abilities can be enhanced even when physical activity is introduced in the chronic stroke phase (beyond 3 months after a stroke).

"Physical activity is extremely helpful for stroke survivors for a number of reasons, and our findings suggest that this may also be a good strategy to promote cognitive recovery after stroke" said lead author Lauren E. Oberlin, a graduate student at the University of Pittsburgh. "We found that a program as short as twelve weeks is effective at improving cognition, and even patients with chronic stroke can experience improvement in their cognition with an exercise intervention."

The researchers analyzed general cognitive improvement, as well as improvement specific to areas of higher order cognition: executive function, attention and working memory. Exercise led to selective improvements on measures of attention and processing speed.

The researchers also examined if cognitive improvements depended on the type of physical activity patients engaged in. Previous studies on healthy aging and dementia populations have found that aerobic exercise by itself is enough to improve cognition, but the effects are increased when combined with an activity such as strength training. Consistent with this work, the authors found that combined strength and aerobic training programs yielded the largest cognitive gains.

"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," Oberlin said. "This has substantial effects on quality of life and functional improvement, and I think it's really important to integrate this into rehabilitative care and primary practice."

https://www.sciencedaily.com/releases/2017/02/170222152746.htm

Exercise can reduce stroke risk

July 18, 2013

Science Daily/University of Alabama at Birmingham

A new study from researchers at the University of Alabama at Birmingham (UAB) is one of the first to study the relationship between exercise and stroke in a large biracial cohort of men and women in the United States. The findings are published in the American Heart Association Journal Stroke.

Using 27,000 stroke-free blacks and whites ages 45 and older in the United States from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study cohort, researchers examined the association of self-reported physical activity with incident of stroke.

Participants were classified at baseline as being in active (i.e., no workouts in a typical week), moderately active (workouts one to three times per week) or vigorously active (workouts more than four times per week), and they were followed for an average of 5.7 years.

The results showed that physical inactivity was reported by 33 percent of participants and was associated with a 20 percent increased risk of stroke. Those who reported they exercised at least four times a week were less likely to experience a stroke or mini-stroke. Among men, only those who exercised four or more times a week had a lower stroke risk. Among women, the relationship between stroke and frequency of activity was less clear.

"The protective effect of intense physical activity may be through its impact on traditional risk factors such as hypertension and diabetes," explained Virginia Howard, Ph.D., UAB professor of epidemiology and senior study author.

"These findings confirm past results of studies done in only men or only women in limited geographical areas," Howard said. "By using the REGARDS cohort, our study was able to use a larger and more diverse population to show that participating in regular physical activity is associated with lower stroke risk."

Howard added that stroke is preventable, and physical activity is a major modifiable risk factor for stroke. "This should be emphasized more in routine physician check-ups, along with general education on the proven health benefits of regular physical activity on other stroke-risk factors including high blood pressure, diabetes and obesity," Howard said.

Study limitations highlighted include that the results are based on self-reported levels of physical activity, and self-reported data may not be a reflection of the truth. Also, investigators did not have data on the type or duration of the exercise in which people engaged, nor the number of sessions. Howard suggested future studies should consider different ways to measure physical activity through: use of more questions; devices such as accelerometers and heart monitors that can provide more objective data; and capturing information on other dimensions of physical activity such as frequency, intensity and duration.

http://www.sciencedaily.com/releases/2013/07/130718130456.htm