Media Coverage

Rebuilding the Body

122831-38589Katherine Dedyna, Times Colonist
Published: Thursday, January 14, 2010

An estimated 6,500 British Columbians suffer strokes every year, and barely a third recover with only minor or no impairment.

To better those odds, neuroscientist Paul Zehr is bringing 19th-century research into the 21st century at the Centre for Biomedical Research at the University of Victoria.




The approach involves strengthening the body's dominant side, which was found at Yale University back in 1894 to automatically boost the weaker side by one-third the improvement in the stronger side. Called cross-education, it sounds counter-intuitive but holds "tremendous" potential, Zehr says.

"For a long time, strength training after stroke was not thought to be a good idea," he explains.

While there's now more medical literature in favour, "it's not universally well-known that it's beneficial."

Strength training is being tried in tandem with so-called "forced use" of the limbs on the side most affected by the stroke, rather than learning to do tasks with the less affected side.

"The best thing is always to use the hand or the leg that's really hard to move," he says. It's hard work, fatiguing and painfully slow but ultimately the way to rebuild neural pathways to maximize recovery.

And if the hand or leg is just too incapacitated to move?

That's where cross-education comes in.

After a colleague in Australia alerted Zehr to the Yale study, another colleague in Saskatchewan tested it on volunteers wearing casts.

"They were able to offset most of the strength loss in their casted limb, which is really cool," Zehr told the December meeting of Café Scientifique.

He squishes a Nerf brain to illustrate the brain's remarkable ability to rebound after blot clots cause oxygen deprivation.

The UVic lab is already working with stroke patients who have experienced "drop foot" on a leg that cannot be activated. They're trying to strengthen the weak leg muscles that produce drop foot through six-week sessions of strengthening exercise.

"Ideally you could strengthen the muscles in the leg, and hopefully the expression of the drop foot would be reduced in walking," Zehr says.

This capitalizes on neuroplasticity -- the nervous system's ability to reconfigure itself and continue to control movement by forming new neural connections that compensate for injury.

Increasing the strength of the weak limb to the point it can be exercised is "such a big part" of patients' ability to do the exercises central to stroke recovery.

"You can recover a lot of function in the brain after damage," Zehr says, but "unless the nervous system is called upon to make these changes, it won't happen."

Zehr will know more about how useful the current cross-education research will be within the next year.

Meanwhile, he's looking for 75 more people who have had strokes six months ago or longer to take part in research. Call 250-472-5487 or e-mail This email address is being protected from spambots. You need JavaScript enabled to view it.

This email address is being protected from spambots. You need JavaScript enabled to view it.




- About 50,000 strokes occur each year in Canada, with some people having more than one.

- About 14,000 Canadians die from stroke annually; 300,000 are living with the effects.

- A stroke survivor has a 20 per cent chance of having another stroke within two years.

- After age 55, the risk of stroke doubles every 10 years.

Of every 100 people who have a stroke:

- 15 die

- 10 recover completely

- 25 recover with a minor impairment or disability

- 40 are left with a moderate to severe impairment

- 10 are so severely disabled they require long-term care

- The average acute care cost per stroke is $27,500

Source: Heart and Stroke Foundation of Canada