Asst. Prof. Lara Boyd’s research is already showing promising results - photo by Martin Dee

UBC Reports | Vol. 55 | No. 2 | Feb. 5, 2009

Priming the Brain to Recover from Stroke

By Catherine Loiacono

For the 300,000 Canadians living with the aftermath of a stroke, partial paralysis and loss of independence is a daily reality.

Now a UBC brain stimulation technique that primes the brain to relearn and retain old movements is showing encouraging results for faster and more effective recovery. A wand, connected to a computer, is placed adjacent to persons head and a stimulus is applied.

“Currently, there are no drugs to help stroke patients regain mobility,” says Lara Boyd, UBC assistant professor of Physical Therapy in UBC’s Faculty of Medicine. “Thus far, physical therapy has proven to be an effective treatment for stroke patients to regain mobility. However, one of the biggest challenges is the time and amount of practice it takes for the brain to relearn an old movement.”

The two-part study tests a healthy brain first to ensure the technique is safe and that there are no adverse effects and then applies the same technique to a stroke-affected brain. The study is currently in the second phase.

Following a stroke, the affected part of the brain is no longer active because of the loss of blood flow, which causes brain cell death. The area of the brain affected by the injury determines the patient’s inability to move, see, remember, speak, reason and read and/or write.

“One of the reasons that it is so difficult for the brain to recover from a stroke and reorganize itself is that the side of the brain that is damaged becomes suppressed while the undamaged side becomes hyperactive,” says Boyd, who is a Canada Research Chair in Neurobiology of Motor Learning. “The left and right side of the brain become unbalanced. It becomes more difficult for the affected side of the body to move because the damaged side of the brain is suppressed. Conversely, the unaffected side of the body moves much easier because the undamaged side of the brain becomes hyperactive.”

This negative feedback loop helps explain why it becomes increasingly difficult for stroke patients to regain mobility.

“Fortunately, the brain is an amazingly dynamic organ that can reorganize itself,” says Boyd, whose current study looks at the benefits of applying an electromagnetic stimulus to the stroke affected section of the brain. “What we want to do is to stimulate and enhance brain cell reorganization around the damaged part of the brain.”

In doing so, Boyd believes that the brain can reorganize itself and find an alternate pathway to performing a previous movement.

The first part of the study tested individuals who had never suffered a stroke. The participants received an electromagnetic stimulus and were then asked to practice a specific movement. Participants who received the stimulus demonstrated increased and improved learning for 15 - 20 minutes following the stimulus.

“Preliminary results of our research on non-stroke patients show that if you pre-excite the brain by applying an electromagnetic stimulus, motor learning and retention of skill is improved and retained,” says Boyd. “We are currently applying this technique to the stroke affected brain and the available data is positive. We are quite optimistic that this approach will work and we expect results in the coming months.”

According to the Heart and Stroke Foundation, each year, there are between 40,000 to 50,000 strokes in Canada and close to 16,000 Canadians die.