Jessica Nguyen

Parkinson’s Disease (PD) is expected to affect more than one million people in the United States by the year 2030, highlighting the growing need for more precise tools for measuring and monitoring symptom progression for the purpose of better patient-specific treatment, and care options for those affected. The clinical pull test is used to determine the progression of balance impairment during disease progression, but is limited by its inconsistency of perturbation. Additionally, its use of coarse rating causes difficulty when measuring fine differences in balance impairment. Being able to track small differences in balance impairment across time may allow for better understanding of patient-specific rate of balance impairment, potentially as a predictive measure of future progression. In this experiment, a treadmill method for the pull test was used to standardize the balance perturbation, and gait timing was quantified by a blind rater to explore whether measurements of balance impairment could distinguish between PD patients with and without REM Sleep Without Atonia (RSWA). Here we show there is no significant correlation between duration of the swing phase of steps following a postural perturbation and diagnosis of PD-RSWA+/- groups, nor is there a significant correlation for the number of steps taken to regain balance. Therefore, coarse measurements of balance impairment may not be appropriate for distinguishing RSWA in PD patients, and a different method such as center of pressure principal component analysis may be beneficial to analyze in the future, to further explore the RSWA prognosis. An application of the treadmill method that will be analyzed is the comparison of rates of balance impairment between subgroups over three years. Swing duration and step count are insufficient gait parameters for association with RSWA, but rate of progression of these parameters may be able to distinguish RSWA and allow for prediction of prognosis.