Measuring the brain's white matter and how it affects thinking in Parkinson’s disease

Alex MacKay, Professor, Department of Radiology, Physics and Astronomy; Director, MRI Research Centre, University of British Columbia
Funded by Quebec Research Fund on Parkinson and Parkinson Society British Columbia
Pilot Project Grant: $45,000

Scientific Title: Assessment of “normal appearing” white matter in Parkinson's disease and its association with cognitive dysfunction

One of the substances in the central nervous system that appears critical for healthy thinking and reasoning is myelin – the fatty tissue known as white matter in neurons, which connects and conducts the signals cells send to one another. The more myelin, the faster those connections among cells.

At the University of British Columbia, physicist Alex MacKay and his colleagues have created a new technique using Magnetic Resonance Imaging (MRI) to measure the myelin in people's brains. Now, they're testing the theory that the breakdown or loss of myelin within the brain contributes to the problems in thinking and reasoning that many people with Parkinson's disease experience, sometimes before the stiffness, rigidity and tremors that more commonly flag their diagnosis.

MacKay and his team have demonstrated that people with multiple sclerosis have less myelin and also have cognitive problems, and drug companies are already testing medications that can either reduce or prevent the breakdown of myelin. If MacKay can demonstrate that the same process occurs in people with Parkinson's, the new drugs under development for MS and other diseases could ultimately help people with Parkinson's disease too. The companies will also have a way to tell if their drugs are repairing myelin or stopping its loss.

“It's a very exciting time,” says MacKay. “Clinical trials are happening as we speak.”

McKay will use this non-invasive imaging technique to measure the myelin in the brains of people with Parkinson's disease, particularly in the frontal lobe, which controls judgment, reasoning and other forms of executive functioning. The people participating in the imaging study will also undergo cognitive testing, so the researchers can correlate their thinking and reasoning skills to their myelin measurements.

This is the first time researchers have used MRI scans to investigate a link between myelin and Parkinson's, and there is still a lot of work necessary to understand how myelin breakdown is related to the death of dopamine-producing cells, MacKay cautions. But he hopes this new line of enquiry will explain one portion of the Parkinson's puzzle – a puzzle in which he has a personal stake.

“I have two very good friends who have Parkinson's disease,” says MacKay. “I relate very much to this disease and how rough it is on those who have it.”