April 17, 2026 | Early dementia with Lewy bodies (DLB) and early Parkinson’s disease share several symptoms and are often misdiagnosed in early stages. It is critical to accurately distinguish the two diseases because of their contrasting disease paths. DLB has a median survival rate of less than five years while Parkinson’s patients can live a decent quality of life for 10-15 years. Reliable early diagnostic markers that can help track disease progression are key to preventing misdiagnosis and ensuring patients receive the correct treatment. Fortunately, walking behaviors may be early diagnostic markers for neurodegeneration.
“Walking is a very complicated motor behavior,” says Kaylena Ehgoetz Martens, associate professor of the Department of Kinesiology and Health Services at the University of Waterloo and lead author of the study. “Because it's control requires coordination across a distributed network of brain regions spanning the brainstem, the midbrain, and the cortex, detecting different walking features might indicate pathological burden at an early stage.”
Ehgoetz Martens and her team conducted a study to characterize and differentiate the walking behaviors between Parkinson’s patients and DLB patients at early stages during normal walking and when performing tasks (Gait & Posture, DOI: 10.1016/j.gaitpost.2025.110034).
Difference in Gait Behaviors
The study consisted of 26 early Parkinson’s patients, 20 early DLB patients, and 16 participants in a healthy control group. Participants were excluded if they had any co-existing neurological conditions or movement disorders outside of Parkinson’s and DLB. Participants were also excluded if they had a mood disorder and/or severe mental illness, such as bipolar disorder, anxiety disorders, depression, and schizophrenia. The patients were tested while still on their medications with 26 Parkinson’s patients and seven DLB patients on levodopa or a dopamine agonist. 19 DLB patients were on cholinesterase inhibitors for their cognitive symptoms.
The team had the participants walk across a pressure sensor walkway under three different conditions: Baseline (normal self-paced walking), Easy Dual Task (self-paced walking while counting backward from 100 by serial 1’s), and Hard Dual Task (self-paced walking while counting backward from 100 by serial 7’s). The participants were not given instructions regarding task prioritization when completing the dual task walking conditions.
According to Ehgoetz Martens, the dual-task conditions were meant to unearth potential symptoms that may be concealed. When visiting a doctor, some patients may mask their symptoms, which can prevent an accurate diagnosis.
When examining the gait characteristics during baseline walking, it was revealed that velocity, step length, step time, stance time, and variability were able to distinguish DLB from Parkinson’s with moderate accuracy. The researchers found that DLB patients had substantially worse gait performance compared to Parkinson’s patients. Mainly, DLB patients had decreased velocity and step length and longer stance time. These results support previous studies on DLB patients that also demonstrated slower speeds, shorter stride lengths, and longer stance time. DLB patients also took wider steps than Parkinson’s patients during normal walking, which the researchers believe was done to compensate for instability.
There were no differences in asymmetry between the DLB and Parkinson’s groups, which contrasts with previous studies. A possible explanation could be due to medication, as drugs like levodopa are meant to alleviate motor symptoms.
More Information is Needed
A first-of-its-kind feature of this study was investigating whether increasing cognitive complexity during dual tasking influenced gait performance between Parkinson’s and DLB patients. Increasing the complexity during dual-task walking while counting backwards by 1’s to 7’s did not show additional gait differences between the two diseases. However, 25% of DLB patients were unable to complete the serial 7’s task, indicating that, from a clinical perspective, counting back from 100 by seven could be used to indicate if a patient has DLB instead of Parkinson’s. Though, it should also be considered that the serial 7’s task may be too difficult for the DLB patients to carry out, which could be considered a study limitation.
“Unfortunately, if they couldn't finish the trial, we couldn’t look at their walking during that difficult condition,” explains Ehgoetz Martens. The team is currently trying to optimize the right dual-task pairing that can retain participants while still making it complex enough to reveal differences, with counting backward by serial 3’s being a possible “sweet spot.”
Another limitation of the study is the small sample size. To fully assess the significance of gait measurement, a larger population is needed. Ehgoetz Martens also mentions that some of the variability results were underpowered due to the small sample size. Another limitation is testing participants who are already on treatment. There is an effect of treatment that may also “mask” some inherent difference that would be there in prodrome because the patients haven’t started treatment yet, explains Ehgoetz Martens.
Are Gait Measurements Clinical-Ready?
“I think we’re a little bit premature in terms of if clinicians could use this now based on these study results,” states Ehgoetz Martens. “But I think starting to use and embed digital measures within the clinic is definitely imminent.”
Despite the small sample size, walking behavior shows promise as a reliable prognostic and diagnostic marker for neurodegenerative diseases. More importantly, the study serves as “scaffolding” with other works of looking for prodromal signals over time and cross-sectionally across different diseases that have overlapping symptoms.
“It’s just such a rich and complex behavior that we need to lean into and maybe consider amongst the other clinical tasks using a more quantitative lens.”