Developing an exercise prescription for stroke recovery
Researcher Andrew Robertson pulls headgear (he calls it a transcranial Doppler ultrasound) over his scalp and points to the computer screen in front of him.
The pointy graphs and colourful lines on the screen represent the speed of blood flow in the brain, measured by the headgear before, during and after exercise.
“We want to know how exercise changes blood flow to the brain,” says Dr. Robertson, a physiologist and post-doctoral researcher with the HSF Canadian Partnership for Stroke Recovery. “We want to know if there is an ideal prescription of exercise that promotes changes in the brain.”
And what does this have to do with stroke?
Researchers are looking to see if exercise can increase the amount of blood getting to under-supplied and sluggish areas, feeding cells and firing neurons. The goal is to help people with mild or moderate strokes to think more clearly and improve their memories.
As part of a CPSR-funded project called RISE (Recovery Improved post-Stroke with Exercise), Dr. Robertson is putting research participants on stationary bikes and measuring blood flow at low and high intensities of exercise. The purpose is to stimulate expansion of blood vessels and circulation in the brain.
“We believe the greatest benefit will be in areas of the brain involved with complex thought processes, such as decision-making and attention, which are important for maintaining independent living,” says Dr. Robertson, who is working with lead CPSR-Investigator Dr. Bradley MacIntosh on the project.
“We want to see if exercise is a way of increasing the amount of blood to an area of the brain that may already be at a disadvantage.”
The six-month study is a collaboration between researchers at Sunnybrook Health Sciences Centre and Toronto Rehab. In the first stage of the study, healthy volunteers take part in a supervised exercise routine at Sunnybrook one day a week and exercise at home four or five days a week. Researchers study brain blood flow at the three- and six-month marks to measure the relationship between blood pressure, blood flow in different regions of the brain and response to cognitive stimulation.
The next phase of the study involves people who have had TIAs, mild and moderate strokes.
“We want to see if we can train the blood vessels so they can respond more efficiently after exercise and help protect the brain in as many ways as possible,” Dr. Robertson says.