Doctors often struggle to distinguish early dementia with Lewy bodies from early Parkinson's disease. The two neurological conditions share many symptoms, including changes in movement, and are frequently misdiagnosed in their early stages. New research from the University of Waterloo suggests that quantifying walking behaviour might be a useful way to tell these diseases apart.
The study found that people with early dementia with Lewy bodies walk more slowly, take shorter steps and have a lower walking rhythm than people with early Parkinson's disease. These differences were most pronounced when participants walked while performing a second task, such as counting backward.
"We compared stepping patterns between individuals with early dementia with Lewy bodies and people with early Parkinson's disease to see whether walking behaviour could help distinguish the two conditions and found that they can," said Dr. Kaylena Ehgoetz Martens , a professor in Waterloo's Department of Kinesiology and Health Sciences and lead author of the study. "The findings highlight the promise of measuring movement in a more detailed manner which could address a significant clinical problem. Because the two diseases look similar in their early stages, patients may receive an incorrect diagnosis, which affects treatment decisions, care planning and expectations for patients and their families."
Simple yet quantitative walking assessments, which can be performed in clinical settings, could help clinicians diagnose patients more accurately and at an earlier stage. Earlier diagnosis may allow for earlier intervention, more targeted symptom management and clearer guidance for caregivers.
While the researchers expected to see differences between the groups, one result stood out.
"Walking without interference from a secondary task was less effective at identifying differences than walking while multitasking," Ehgoetz Martens said. "Asking participants to walk while counting backward revealed changes that weren't as obvious during regular walking.
"Ultimately, the goal is to identify individuals sooner, intervene earlier and improve quality of life before symptoms become more severe."
The results point to the importance of cognitive load — how attention and movement interact — in distinguishing neurological diseases that can otherwise appear similar.
The work reflects the University of Waterloo's Health Futures focus, which brings together researchers across health, engineering and data science to develop practical, technology-enabled approaches to improving care. By translating everyday movement into meaningful clinical insight, the research highlights how accessible tools can support more equitable and accurate diagnosis.
The researchers plan to expand their approach to other conditions and to people in the earliest, pre-clinical stages of disease, including those known to be at higher risk.
The study, titled " Differentiating gait behaviours between early-stage dementia with Lewy bodies and Parkinson's disease ," was published in the journal Gait & Posture.
