Main idea: Patients with Parkinson’s disease can be diagnosed through posture sway which makes diagnostics easier.
The severity of Parkinson’s disease (PD) is difficult to assess objectively 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 underwent tests of cognition and quality of life: Montreal Cognitive Assessment (MoCA), Neuropsychiatry Unit Cognitive Assessment (NUCOG), and, for the patients, the Parkinson’s Disease Questionnaire (PDQ-39-1), and assessment of clinical status using the motor component of the MDS-UPDRS. 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, to a lesser degree, with the UPDRS-III in patients with PD. These results suggest that motor and non-motor symptoms of PD are associated in patients, and that postural sway shows potential as a possible measure of underlying disease status in PD.