Tremor, bradykinesia (slowness of movement), rigidity (stiffness) and walking/balance impairment are the major signs of Parkinson's disease; a middle-age onset with slow progression is archetypal. However, subgroups of PD patients are thought to have a ‘more rapid’ or ‘slower progression’ of clinical decline than the average case.
We will access the well-established longitudinal Movement Disorder Data Repository at Rush University Medical Center with attention to three key features of PD: age of onset, profile of tremor and postural-imbalance/gait, and exposure to amantadine. We will analyze the individual experiences of around 15,000 office visits by 2,000 PD patients and study the standard rating scale of PD impairment (i.e., the motor UPDRS), while carefully maintaining the privacy of the individual records. We are searching for “slow progressors” whose PD remains mild over a long duration. It is thought that slow progressors may hold molecular or environmental keys to future interventions to slow disease progression. Identification of this relevant subgroup is therefore important for future research.
In this study we aim to answer three main questions: (1) whether age of onset distinguishes “slow progressors” from more rapid progressors, (2) whether individuals with more prominent tremor symptoms than postural-imbalance gait symptoms progress at a different speed from those with less prominent tremor, and (3) whether amantadine exposure in a clinical practice is associated with a different rate of progression. These questions are to be answered based on the experience of the patients in the data repository.
Dr. Leurgens aimed to determine whether age of onset, profile of tremor, and postural-imbalance/gait or early use of amantidine predict patient-specific trajectories of motor UPDRS scores and Hoehn and Yahr staging.
This project demonstrated the importance of non-tremor scores in predicting disease progression. The higher the non-tremor score, the more likely the patient was to progress more quickly. Age of onset did not influence changes in tremor scores or disease progression. Higher non-tremor score at first visit predicted increased disease worsening. Early amantadine treatment did not affect disease progression.