Stroke victims aided by walk
Study: Exercise changes brain
WASHINGTON - Walking on a treadmill three times a week helped stroke survivors improve their mobility and physical conditioning but also led to a "rewiring" of the brain reflecting these gains, US researchers said yesterday.
Some of the treadmill walkers achieved major improvement despite coming into the study needing a wheelchair or walker to get around, and brain scans revealed positive brain changes following six months of such exercise, the researchers said.
"I think it's one of the better pieces of news in a while - in a long while - for the stroke survivor," Dr. Daniel Hanley, a neurology professor at Johns Hopkins University School of Medicine in Baltimore who helped lead the study, said in a telephone interview.
"Improvement can occur a long time - meaning months and years - after the stroke," added Hanley, whose findings were published in the American Heart Association's journal Stroke.
Stroke survivors can be left with paralysis or loss of muscle movement. A stroke can impair a person's gait, reducing one's mobility and fitness and promoting chronic disability.
Stroke most commonly occurs when the blood supply to a part of the brain is stopped or greatly reduced, depriving it of oxygen.
The study involved 71 patients, average age 63, who had a stroke an average of about four years earlier. About half were selected to walk on a treadmill for 40 minutes three times a week for six months, while the rest did stretching exercises for the same amount of time instead of the treadmill.
Because of their stroke-related physical impairment, some of the treadmill walkers were assisted by a supporting sling or tether in order to do the exercise.
To assess possible brain changes, the researchers performed functional magnetic resonance imaging exams before and after the six months of the study on 32 of the people, selected equally from the two groups.
In the treadmill walkers, the scans detected increased activation in brain areas associated with controlling gait and walking, including the cerebellum and midbrain, researchers said. No such changes were seen in the others.
In addition, the treadmill walkers improved their walking speed by 51 percent compared with 11 percent for the stretching group. And the treadmill walkers improved their mobility and aerobic fitness by about 18 percent, compared with no improvement in the stretching group, the researchers said. "Some of these people were actually in a wheelchair when they started, and a lot were using canes and walkers," Hanley said, noting that some were able to give these up or lessen their dependence on them after the treadmill use.
Hanley said the gains came even after those in the study had finished standard physical therapy following their stroke.
"Many stroke survivors believe there's nothing to be gained from further rehabilitation, but our results suggest that health and functional benefits from walking on a treadmill can occur even decades out from stroke," added Dr. Richard Macko, a professor of neurology at the University of Maryland School of Medicine who also helped lead the study.