Baseline Wearable Turning-Derived Signature and Dopamine Transporter-Derived Measures in Relation to Subsequent Motor Progression in Parkinson’s Disease: An Exploratory Longitudinal Study

Parkinson’s disease (PD) shows heterogeneity in motor progression, complicating prognostic assessment. Dopamine transporter (DAT) imaging provides an in vivo measure of nigrostriatal dopaminergic integrity, whereas wearable gait assessment quantifies motor performance. However, the prognostic value of baseline (BL) DAT-derived measures and wearable gait characteristics remains incompletely understood. We investigated whether BL DAT-derived measures and a limb-focused wearable turning movement-dynamics signature (turning-derived signature) were associated with subsequent motor progression in PD. Twenty-three individuals with PD underwent BL PET imaging, wearable gait assessment, and clinical follow-up. Motor progression was defined using a cohort-specific exploratory threshold of ΔUnified Parkinson’s Disease Rating Scale (UPDRS) Part III ≥ 1.5 points, derived within this cohort using Hoehn and Yahr (H&Y)-stage worsening as the clinical anchor. Twelve participants were classified as motor progressors and 11 as non-progressors. The turning signature yielded an AUC of 0.750, while DAT-model AUCs ranged from 0.462 to 0.500. The clinical model yielded an AUC of 0.962; adding the turning signature yielded an AUC of 0.871. These findings suggest that the BL turning-derived signature contains an exploratory prognostic signal but does not establish incremental value beyond clinical severity. The progression outcome was derived within this small cohort, and external validation is required.