Biomarkers - Dr. Michael Vesia - Opening a new window on the link between intention and action in Parkinson’s Disease
Dr. Michael Vesia, Post-Doctoral Fellow
Sensorimotor Connectivity in Parkinson’s Disease: Bridging Neuroimaging, Neurophysiology, and Treatment
The intricate functional connections within the brain, and its ability to alter those connections to overcome damage or disease, make it a daunting subject for scientific inquiry. Michael Vesia, a post-doctoral fellow at Toronto’s Krembil Research Institute, is investigating the interaction between the area of the brain that collects, exchanges and communications information, and its ability to direct our physical movements, in an effort to get this complex organ to reveal its secrets.
Vesia uses a technique known as transcranial magnetic stimulation (TMS), involving a magnetic field that is directed across the brain. The technology produces electrical currents in targeted locations, allowing researchers to assess and alter brain activity in cases where that activity has been compromised by Parkinson’s disease.
For example, by identifying connections made in the brains of healthy individuals when they form the intention to move a hand, Vesia can compare the results with those of people with Parkinson’s disease who are asked to do the same thing.
“What we find in Parkinson’s patients is that some of these connections are aberrant — they’re misfiring, they’re overactive, under-active,” says Vesia.
Vesia also wants to document the brain activity in people with Parkinson’s who are taking dopamine replacement medication, such as levodopa. The medication replaces dopamine lost through Parkinson’s when dopamine-producing brain cells die.
“The goal is to see how under a particular treatment, such as L-dopa, these connections may change,” Vesia says.
Eventually, TMS might also be able to redirect brain connections, restoring people’s movement control.
“It might be a way of adjusting the circuitry based on the disease,” Vesia explains. “By studying how these circuits are modulated, we can investigate how different therapies may affect these circuits.”
Vesia’s work takes advantage of another well-established medical tool, functional magnetic resonance imaging (fMRI). This method also indicates functional locations within the brain, adding to the amount of information researchers can collect during the brain’s resting state as well as when the brain is undertaking a specific action. Vesia hopes this brain imaging approach will point to biomarkers to measure the effectiveness of different strategies for dealing with the disease. Such strategies can also act upon the brain’s extraordinary plasticity, its ability to rewire pathways in the brain that have malfunctioned.“You’re manipulating and reorganizing brain network interactions,” he concludes, “harnessing the brain’s plasticity to improve behaviour.”