Neuroscience researcher turns spotlight on gaps in stroke rehabilitation

In the days following a stroke, more than 60 per cent of patients suffer from vision problems. These impairments can manifest in many ways, but all are detrimental to overall stroke recovery and quality of life. While common, post-stroke vision problems and their connection to motor impairments are vastly under-studied.

For Dr. Isabelle Poitras, PhD, this area of stroke rehabilitation is where she hopes to make an impact. “Helping people is my main goal. It has been since I started my training, and it stays my main goal,” she says. Poitras, a postdoc in the Department of Clinical Neuroscience at the Cumming School of Medicine (CSM), has been awarded a Killam Postdoctoral Fellowship to research better assessment and treatment of post-stroke visual problems.

The two types of visual problems that Poitras will be researching are visual field loss and visual neglect. Visual field loss is the experience of patients no longer being able to see in certain parts of their field of vision, creating a "blind spot." Visual neglect is when patients aren’t able to pay attention to part of their field of vision, often one side of their body or the other. In both cases, patients’ eyes are functioning normally, but the brain can’t process what the eyes are seeing.

If a patient’s brain can’t process what they see, patients aren’t able to interact with their environment using their limbs. In typical stroke rehabilitation, clinicians will prioritize treating motor impairments, without having a full understanding of how a patients’ visual impairments are affecting their motor skills.

If these problems persist, they can make it extremely challenging for patients to return to daily life. “After a stroke, more than a quarter of patients will have visual neglect, and approximately half will have visual field loss,” says Poitras. “Approximately half of them will regain full vision, but the other half will still have deficits after six months. They will have trouble doing activities of daily living like cooking or dressing themselves. If they are young, they may not return to work.”

Developing new assessment and treatment protocols

Poitras’ goal is to enhance our understanding of the impact of visual problems on stroke survivors, so that they can be assessed and treated more effectively. First, she will be using specialized robotic equipment that can assess how a patient’s eye movement and motor movements relate to one another.

Patients sit with their arms supported by a robotic exoskeleton, while looking at a screen that is showing a game that requires patients to use their eye-hand co-ordination. Their eye and arm movements are being tracked at the same time, allowing Poitras to assess how a patients visual and motor impairments are related.

“Visual impairments are typically not systematically assessed post-stroke, and we don't have a lot of information on them,” Poitras says. By following this assessment protocol, Poitras will establish a comprehensive database on visual impairments and abnormalities in eye movements during the stroke recovery process.

The second phase of Poitras’ research is to test an intervention using non-invasive brain stimulation, combined with visual rehabilitation. Brain stimulation (called repetitive transcranial magnetic stimulation, or rTMS) is delivered via a large magnet, called a “coil,” that patients sit under as it stimulates a specific area of the brain. After 20 minutes under the magnet, patients will do motor or visual therapy activities.

“When you stimulate a part of the brain, it’s possible for the brain to reorganize information more than just with therapy by itself,” Poitras says. “If you do rTMS alone, not a lot of results will come from that. But, for example, if you gain 20-per cent improvement from just doing the therapy alone, you can gain 30-35 per cent with the rTMS.”

Making a difference, thanks to the Killam Postdoctoral Fellowship

For Poitras, the goals of her research are tied to her previous training as an occupational therapist. When working in clinics, she often saw patients who didn’t have adequate services or treatments available to help them rehabilitate. “I’m really interested in undertreated conditions,” she says. “It’s seeing what patients need and trying to make the best project so that they can have services in the future.”

Poitras moved to Calgary from Quebec City only recently, joining Dr. Sean Dukelow’s lab at CSM. Dukelow, MD, PhD, is a professor in the Department of Clinical Neuroscience and medical director of stroke rehabilitation for the Calgary Stroke Program. After an internship in Dukelow’s lab in 2022, Poitras was impressed and inspired by the stroke-treatment research underway at UCalgary and wanted to come back.

“The Killam Fellowship allows me to be here and do research that I’m passionate about, and give back to my community,” says Poitras. “It means that I can come here and make a difference.”