Using non-invasive brain stimulation to unfreeze gait

Alexandra Potvin-Desrochers
PhD Student
McGill University
Graduate Student Award
$20,000 over 2 years
Neural mechanisms of freezing of gait in Parkinson’s disease

Freezing in place while walking, which can also result in falling, is an aspect of Parkinson’s disease some people experience daily.

Often, freezing contributes to social isolation, because people are afraid to leave home in case they get stuck or fall.

At McGill University, PhD student Alexandra Potvin-Desrochers is studying the areas of the brain involved in freezing of gait, to try to come up with an effective treatment.

She has already demonstrated that in people with Parkinson’s, there is an increased level of connectivity between the areas of their brain responsible for sensory processing and visual spatial processing, compared to the brains of people with Parkinson’s who don’t experience freezing of gait.

Potvin-Derochers’ hypothesis is that freezing occurs as a result of an overload in the processing of a variety of inputs into the brain, including messages from the cognitive, limbic and motor and sensory regions.

Now Potvin-Desrochers is using rTMS—repetitive Transcranial Magnetic Stimulation—to pinpoint the precise areas of the brain involved in processing sensory data. This non-invasive technique places a magnetic coil on the scalp and creates a low-level magnetic field to stimulate or reduce the activity of the neurons in the areas of the brain it is placed above.

Potvin-Desrochers is determining whether treating people with Parkinson’s with rTMS can reduce freezing. By changing the placement of the magnetic coil and then testing people’s walking ability, she’ll locate the precise areas of the brain that are involved.

“There are not a lot of treatment options for freezing of gait. We would really like to find a way to reduce freezing of gait in these patients.”

Ultimately, she hopes to combine rTMS with balance and gait training to see if people get better results than with balance and gait training alone.

“There are not a lot of treatment options for freezing of gait,” Potvin-Desrochers says. “We would really like to find a way to reduce freezing of gait in these patients.”

Some clinics in Canada already use rTMS to treat depression, and Potvin-Desrochers hopes her work will eventually lead to making the technology more accessible for people with Parkinson’s and other neurological diseases.

Potvin-Desrochers was just 8 years old when she received a model of the brain for Christmas, sparking her love affair with neuroscience. She remains fascinated by how the brain controls movement, and her determination to discover new knowledge and apply it to clinical practice led her to this research.

“It’s important for me to be involved in the clinical aspect of what I do, so it can better guide the practices of physicians and neurologists,” she says.