TOPLINE:

A slower peak angular velocity during turning while walking could help in tracking motor progression in the prediagnostic phase of Parkinson's disease (PD) and predicting an elevated risk in older adults approximately 8.8 years before clinical diagnosis.

METHODOLOGY:

• Researchers conducted a decade-long longitudinal study to assess whether a decline in turning performance among older adults could predict the future risk for PD.
• They included 933 participants aged 51-85 years who were followed up over five visits between 2013 and 2023. Of these, 23 were diagnosed with prediagnostic PD.
• Participants' turning performance was assessed using multiple Opal sensors with one positioned on the lower back at the level of the fourth and fifth lumbar vertebrae, while walking along a 20-m hallway at a normal pace for 1 minute.
• Turning measures were calculated from three or more turns, focusing on seven metrices, including turn angle; turn duration; angular velocity at the start, middle, and end of the turn; and mean and peak angular velocity across the entire turn.

TAKEAWAY:

• Participants later diagnosed with PD had a mean interval of 5.3 years between their first turning assessment and diagnosis and were 5.1 years older at their first assessment than control participants not diagnosed with PD.
• A slower peak angular velocity at baseline was significantly associated with a higher risk of developing PD (model coefficients exp [β], 0.988; P = .045), with abnormalities detected approximately 8.8 years before diagnosis. Other turning characteristic did not show any significant association with the risk.
• Each year increase in age was associated with a 15% higher risk of developing PD, and male sex was associated with a fourfold higher risk (P < .05 for both).
• An up-sampled XGBoost classification model, using baseline age, sex, and peak angular velocity, achieved a sensitivity of 60% for identifying those with prediagnostic PD and a specificity of 80.5% for identifying those without prediagnostic PD (area under the curve, 0.805).

IN PRACTICE:

"Our results suggest that turning measures may aid in predicting the clinical PD diagnosis and enhance a panel of prediagnostic markers for identifying high-risk individuals," the authors wrote.

SOURCE:

This study was led by Morad Elshehabi, MD, MSc, Department of Neurology, University Medical Center Schleswig-Holstein and Kiel University, Kiel, Germany. It was published online on October 21, 2025, in Annals of Neurology.

LIMITATIONS:

This study included a limited number of participants with prediagnostic PD, which may have affected the precision and generalisability of the findings. The algorithm used for the analysis of lumbar wearable device data had limitations in detecting the turning angle. Subtle changes in the prediagnostic stages of turning certainly led to wide CIs when estimating how long before diagnosis these changes occurred.

DISCLOSURES:

This study received open access funding from Projekt DEAL. The authors reported having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.