This multi-site study found group-specific associations between cognitive domains—especially executive function—and quantitative postural sway across sensory standing conditions in people with Parkinson’s disease, older adults, and younger adults, with better executive function unexpectedly linked…

Although it does not identify molecular or druggable targets, the study has translational value for PD by linking cognition to fall-risk phenotypes and supporting sensor-based monitoring and cognitive/rehabilitative interventions to mitigate postural instability.

BACKGROUND: Postural instability is one of the most debilitating symptoms of Parkinson's disease (PD). It is also major concern in healthy older adults (OA), contributing to increased fall risk. Cognitive function plays a critical role in postural control. However, little is known about the specific cognitive domains related to postural control in these populations. This study aimed to examine how postural control relates to different domains of cognitive function across varying standing sensory conditions, and how these associations are influenced by age, PD and PD severity. METHODS: A total of 232 participants (127 people with PD (PwPD) aged 69.51 (7.67)), 52 OA (aged 68.78 (7.92) and 53 younger adults (YA) (aged 23.58 (4.02) were assessed across two sites. PwPD were also categorised based on Hoehn and Yahr (H&Y) stage I, II and III. Participants completed cognitive tests and four standing tasks (eyes open/closed, firm/foam surface). Sway measures (area, velocity, jerkiness, root mean square, and frequency) were collected using six wearable inertial sensors. Hierarchical linear regression analysis examined cognitive predictors of sway within each group. RESULTS: Regression analyses revealed group-specific cognitive-postural associations. In PwPD, OA, YA, and H&Y II, better executive function was linked to increased sway outcomes. CONCLUSIONS: Increased sway outcomes may reflect a more flexible, adaptive postural control strategy, while reduced sway outcomes may reflect a more constrained postural strategy linked to poorer cognition. These findings highlight the importance of considering performance on specific cognitive domains, age, and disease severity when assessing postural control and fall risk in OA and PwPD.