Virtual reality brings real life Parkinson’s awareness

Neuroscientist Kaylena Ehgoetz Martens
Neuroscientist Kaylena Ehgoetz Martens

Canadian neuroscientist Kaylena Ehgoetz Martens has more than an academic interest in uncovering the reasons why almost half of everyone in the advanced stages of Parkinson’s disease experiences terrifying moments of being unable to move.

For three years, Ehgoetz Martens worked at an exercise rehabilitation program with a woman with Parkinson’s disease who experienced severe freezing of her gait. Three times a week, she helped the woman master a series of sensory-based and coordination exercises at the Movement Disorders Research and Rehabilitation Centre at Wilfrid Laurier University. At the end of their work together, the woman went from being largely wheelchair bound to walking short distances. More importantly, her less frequent falls and increased independence improved her outlook on life.

“It totally changed her mood,” Ehgoetz Martens says. “Whenever she was able to walk unassisted, her mouth would be open, smiling from ear-to-ear. It was really important to me that we were able to change how independent and worthwhile she felt for those last few years.”

The woman has since died, but she inspired the neuroscientist’s determination to pursue a research career focused on freezing of gait. Ehgoetz Martens pursued a PhD that demonstrated the link between anxiety and freezing.

Using virtual reality tools, she studied the gait of people with Parkinson’s who walked across a plank that was lying on the floor. When participants wore a headset that created a virtual environment, the program would suddenly “drop” the floor from under the plank, so the participants appeared to be walking nine metres above a deep pit.

Subjects involved in the study included a control group of people without Parkinson’s, and two groups of people who have Parkinson’s: those that experienced freezing of their gait; and those that did not. The latter group were classified as either high anxiety or low anxiety, through a questionnaire. Those with low anxiety reacted closer to people without Parkinson’s, and those with high anxiety reacted similar to those people with Parkinson’s who experience freezing of gait.

“The study demonstrated that anxiety provokes movement breakdown, slower walking and freezing in Parkinson’s disease,” says Ehgoetz Martens. Researchers are beginning to investigate more how the non-motor symptoms of Parkinson’s have an impact on the motor symptoms of the disease.

Last fall Ehgoetz Martens co-authored a research paper with Eric Beck and Dr. Quincey Almeida titled: “Freezing of Gait in Parkinson’s disease: An Overload Problem?”1. Partially funded by Parkinson Canada, the study involved a series of experiments to better understand the underlying causes of freezing of gait and to explore the interaction between cognitive function and sensory-perceptual influences, in this case visual cues. Beck was the primary investigator of the experiments at Wilfrid Laurier University, which were part of his ambitious undergraduate thesis.

Experiment pathways with and without visual cues and a devise to block the sight of leg movements.
Experiment pathways with and without visual cues and a devise to block the sight of leg movements.

Two groups of people with Parkinson’s – one group of “freezers” and one group of “non-freezers” – walked a straight path towards and through, a doorway. In one instance they also had to count the number of times they heard two digits spoken aloud while they walked (dual-task.) Sometimes the path they walked was marked into segments (visual cues) and sometimes the view of their legs moving was blocked from their vision. (See photo, right.) The gait and gaze of the participants was measured during these tasks.

The study found that freezing of gait (FOG) in people with Parkinson’s may be the result of an overload of processing resources in the brain. “The basal ganglia section of the brain, which is affected by Parkinson’s, contains a lot of our “core processors,” explains Ehgoetz Martens. “If they are damaged, our processing capacity is diminished. Visual cues may decrease the demand on the basal ganglia’s processing resources by promoting gait control though alternative pathways in the brain.”  However, Ehgoetz Martens acknowledges that most of us eventually “habitualize” visual cues, so they may no longer be helpful. Further investigation may help with effective strategies to alleviate freezing.

While attending an International Movement Disorder Congress in 2013, Ehgoetz Martens met associate professor Simon Lewis of the University of Sydney and director of the Parkinson’s Disease Research Clinic at the Brain & Mind Research Institute. The Australian researchers are some of the leaders in freezing of gait, reports Ehgoetz Martens.

When she completed her PhD in Canada, Ehgoetz Martens investigated research positions in Australia. She was awarded a two-year, $80,000 Basic Research Fellowship from Parkinson Canada’s National Research Program and is now living and working in Australia at the University of Sydney. “This funding from Parkinson Canada is absolutely critical,” says Ehgoetz Martens. “I could not have pursued this research without it and I am incredibly grateful!”

She will be investigating how anxiety triggers freezing in Parkinson’s by conducting research on patients participating in virtual reality scenarios while they are in a functional magnetic resonance imaging machine. As they manipulate foot pedals to simulate walking, the fMRI will scan their brains to chart the brain structures active during freezing.

It is hoped that the research will result in a new model to determine what causes freezing of gait and new ways to treat and reduce the anxiety that triggers it because part of improving quality of life and even disease severity, comes from treating these non-motor symptoms.
You can read more about this research, along with profiles of other projects funded by Parkinson Canada, at www.parkinson.ca.


1 Beck EN, Ehgoetz Martens KA, Almeida QJ (2015) Freezing of Gait in Parkinson’s Disease: An Overload Problem? PLoS ONE 10(12):e0144986. doi: 10.1371/journal.pone.0144986

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