Motor Symptom Localization Profiles to Track Disease Progression in Parkinson’s Disease
Veronica Ferrer1, Venkat Lavu2, Qingqi Yuan1, Jagan Mohan Reddy Dwarampudi3, Diego Guarin1, Joshua Wong4
1University of Florida, 2University of Arkansas Medical Sciences, 3University of Houston, 4University of Florida College of Medicine - Neurology
Objective:
To determine whether baseline motor symptom localization profiles predict differential rates of motor progression in Parkinson’s disease, aiming to establish localization-based profiles as a tool for better prognostic stratification.
Background:
Parkinson’s disease (PD) often presents with asymmetric motor symptoms, yet this asymmetry is not taken into consideration from the numerous previous motor subtyping algorithms. Given the asymmetric brain changes that are apparent on molecular imaging such as via DaTSCAN, we may be missing an important component of motor phenotyping by not considering symptom localization. Here we propose a quadrant-based labeling system to stratify patients and assess longitudinal disease progression.
Design/Methods:
We conducted a retrospective study of the Parkinson’s Progression Marker Initiative database and collected the following clinicodemographic information: date of diagnosis, disease duration, and the Movement Disorders Society Unified Parkinson’s Disease Rating Scale Part III motor score (UPDRS III) in the medication OFF state. Scores were divided by limb quadrant and classified using percentile (≤33rd percentile = mild, 34-66th percentile = moderate, >67th percentile = severe) and ROC-based thresholds. Patients were categorized by dominance pattern (quadrant, hemibody, bilateral, or none), and these classifications were used to model longitudinal changes in UPDRS III using an ANOVA model.
Results:
602 patients were analyzed. Bilateral patients demonstrated the fastest progression in motor symptoms, while hemibody-dominant patients showed intermediate progression, and isolated quadrant-dominant patients exhibited the slowest progression within the first 5 years of diagnosis. 5 years after diagnosis, there was a statistically significant difference in UPDRS III scores between the groups (p = 0.0005). The mean (SD) for bilateral, hemibody-dominant, and quadrant-dominant patients at 5 years after diagnosis were 34.677 (10.038), 30.474 (15.253), and 24.923 (11.312), respectively.
Conclusions:
This labeling framework provides a novel method for stratifying PD patients and may support earlier identification of individuals at risk for faster decline, guiding monitoring and care strategies.
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