V41. Static sway patterns of individuals with increased risk for, and converters to Parkinson’s disease. Analysis of 700 participants of the TREND-study

Abstract

Background and aim Quantitative assessment of prodromal presentations (e.g. motor signs, hyposmia, depression, REM sleep behavior disorder) of Parkinson’s disease (PD) may be the key to eventually enable earlier diagnosis of this disease. Recent observations indicate that subtle balance deficits belong to these prodromal presentations. Moreover, the higher the number of risk markers and prodromal presentations an individual combines, the more likely is it that this person gets PD. We therefore hypothesized that individuals with a high number of risk factors for PD, as well as individuals with PD who were assessed two and four years before diagnosis (already) show altered static sway characteristics in this risk and prodromal phase of PD. Methods In the first wave of the longitudinal TREND ( Tu binger evaluation of R isk factors for E arly detection of N euro D egeneration)-study ( www.trend-studie.de ), 657 older individuals with and without risk factors for PD (0 risk factors, N = 315; 1 risk factor, N = 240; 2 risk factors, N = 90; 3 risk factors, N = 12) as well as 35 PD patients without clinical evidence for a balance deficit were investigated. Seven individuals out of the 645 developed PD during the subsequent observation period of four years (PD converters). From these individuals, quantitative sway parameters data of the first as well as of the second wave were included in the analysis. Quantitative balance assessment was performed with the McRoberts Dynaport® sensor at the lower back. Participants were asked to stand for 30 s on foam in semitandem stance (i) with eyes closed and (ii) with eyes open. Parameters of area of sway, velocity, acceleration, JERK and mean power frequency (MPF) of sway were analyzed. Results Under eyes-closed conditions, PD patients had a larger area and a lower MPF of sway, compared to the 0, 1 and 2 risk factor(s) cohorts ( p -values. Conclusion To the best of our knowledge, this is the first study reporting about quantitative cross-sectional balance assessment in a large cohort of individuals at risk for PD, as well as about longitudinal balance assessment in PD converters during their prodromal phase over observation periods of up to four years. Our findings confirm previous results from a smaller study which demonstrated static balance differences between high risk individuals for PD and PD patients which were only visible under most challenging conditions. Moreover, results obtained from the PD converters argue for the potential of quantitative balance parameters as trait and state markers in the prodromal phase of PD. Further implications and potential clinical impact of this will be discussed.