Main idea: These results suggest that motor and non-motor symptoms of PD are associated in patients, and, in particular, that postural sway shows potential as a possible measure of underlying disease status in PD, either alone or in combination with other measures.
The severity of Parkinson’s disease (PD) is difficult to assess owing to the lack of a robust biological marker of underlying disease status. The current standard tool is the Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) Postural sway has been shown to correlate with complex brain functioning in other conditions. This study aimed to investigate the relationship between postural sway, MDS-UPDRS and other non-motor measures of disease severity in patients with PD. 25 patients with PD and 18 age-matched controls participated in the study. All participants underwent assessment of postural sway using a force plate, with eyes open and closed. Participants also underwent tests of cognition and quality of life. Patients swayed significantly more than controls. This was most obvious in the eyes-closed condition. Sway path length showed strong correlations with PDQ-39-1, MoCA, and the verbal fluency component of the NUCOG, and in patients with PD.