New tools to change the course of natural recovery after stroke
With sensors strapped to her arm, research assistant Tea Lulic closes her eyes and reaches forward to press a big red doorbell. If she veers off course, Tea hears a musical tone, adjusts her movement and continues towards the target.
To the untrained observer, the activity looks a bit like a party game. But CPSR-Investigator Dr. Joyce Chen is using information gathered from this research to gain valuable insight into how sound promotes learning in the brain, moves muscles, guides limbs and potentially changes the course of natural recovery after stroke.
In the near future, Dr. Chen will use functional Magnetic Resonance Imaging (fMRI) to study the brains of people before and after sound-based therapy to determine how it alters interaction among brain regions.
Her goal is to use sounds, and eventually music, to help people learn to move efficiently and smoothly — preventing pain and promoting use of stroke-affected limbs.
“When you listen to music, many people start moving and tapping to the beat almost spontaneously,” says Dr. Chen, who first trained as a physiotherapist and was “always fascinated by how musical cues could facilitate movements and improve speed of walking in patients with stroke.”
This fascination led her to complete a PhD in cognitive neuroscience and brain imaging at McGill University, examining the neural interactions between auditory and motor systems. She followed that with post-doctoral studies looking at how these brain regions are connected at the University of Oxford, and stroke rehabilitation at Harvard University.
“There is something about music and movement that’s linked . . . We want to know, if we use music as a tool, can we facilitate recovery to a greater extent? What are the brain regions that are helping you learn?” asks Dr. Chen. “We are just beginning to understand how music taps into the reward areas of the brain. Can reward-based learning vis-à-vis music help with stroke recovery?”
In addition to stimulating recovery with sound, Dr. Chen is seeking to activate the brain with non-invasive electrical stimulation.
A study, in collaboration with Dr. Robert Chen (no relation) at Toronto Western Hospital, examines how different types of electrical stimulation affect excitability of neurons in movement areas of the brain. For this they are using transcranial magnetic stimulation and transcranial direct current stimulation. Research is now focused on healthy volunteers, but testing will begin on stroke patients later this year.
With electrical stimulation, researchers want to turn down over-activity on the healthy side of the brain and help boost neuronal activity on the stroke-affected side to restore function.
“What if we apply stimulation early after a stroke? Can we actually change the course of natural recovery?” asks Dr. Chen. “That’s why there is this excitement about brain stimulation.”