Assistant Professor Kristan Leech has received a new grant to study how motivation and walking work together in patients post-stroke.

BY KATHARINE GAMMON

STROKES CAN IMPACT PEOPLE IN MANY WAYS — for example, some people have to relearn to walk or talk. But, in about a third of people who experience stroke, a surprising side effect can appear: apathy.

Apathy has to do with the part of the brain that impacts motivation to engage in different behaviors, Assistant Professor Kristan Leech said.

Leech, who is interested in figuring out how the systems of motor control and apathy are intertwined, has received a federal research grant designed to support an early-stage investigator pursuing a new direction of research.

While Leech has been looking at gait recovery following stroke using biofeedback and intensity-based gait training, the funding will allow her to pursue the new direction of studying the psychiatric phenomenon of apathy.

“I realized there might be something really interesting in understanding this condition that’s present in about 30 percent of people,” she said. “Apathy is a pathological loss of motivation, but — in these cases — we think the stroke has affected a part of their brain that we think is responsible for motivation, so they now have kind of a fundamental loss of motivation due to the stroke.”

Looking at motivation’s impact

The interdisciplinary study will observe 125 people post-stroke with varying degrees of apathy, measuring their walking speed and community engagement using GPS tracking.

The team hopes to determine the relationship between post-stroke apathy and gait speed reserve — “basically, how fast they can walk versus how fast they choose to walk,” Leech explained.

Through the GPS tracking, the researchers can also understand how much people are engaging with their community after a stroke — for example, how much they leave their house to be with others.

The grant also includes funds for brain imaging to identify a brain network linked to apathy.

Leech says that previous research shows that people with stroke have a decrease in the amount of walking they do, but researchers don’t yet know which physical therapy interventions increase the number of steps people take per day — or if that improves one’s mobility within the community.

“We don’t really know where people are taking those steps,” she added. “It’s kind of assumed that if you increase the number of steps you take per day, you’re increasing your participation in your daily life.”

Finally, the study will use MRI to capture imaging to identify the specific signatures in the brain linked to apathy. The scientific community has identified a brain network for apathy in older adults, and the researchers hope to understand if the same network is affected in people who have post stroke apathy by the stroke lesion. “The hope is to understand both the behavioral manifestation and the brain mechanism of apathetic behavior,” Leech said, “to round out the picture of the person.”

Discoveries could lead to better treatment options

The work will ultimately lead to better treatments for people after strokes, by providing a more comprehensive view of how the body and brain work together. “In physical therapy, we’re really focused on the motor behavior that we want to improve,” Leech said. “But I think in the last few years, there’s been more attention paid to, you know, mindset, motivation and other things that impact people’s behavior. If we can uncover a relationship or an association of the psychiatric condition to motor behaviors that we focus on in physical therapy, it can lead to a more well-rounded treatment approach.”

Many disciplines are contributing to the study, including collaborators like Wendy Mack at SC CTSI, Professor of Psychology and Family Medicine Duke Han and Associate Professors of Occupational Science and Occupational Therapy Sook-Lei Liew and Stacey Schepens-Niemiec.

“To do good science just requires a team-based approach at this point,” Leech explained. “There is no way to look at how a psychiatric condition impacts mobility and the underlying brain mechanism without pulling in people that are experts in imaging, psychiatry and neuropsychology.”

The grant also focuses on shifting perspectives in science — something that Leech feels strongly about. This study was inspired by questions that arose in her studies of gait and cognition. “You have to go where the science takes you,” she said. “If you’re too narrowly focused on one thing, you risk not seeing what’s right in front of you.”