Different Imaging Evaluating Performances Between Glymphatic System and Motor Symptoms and Levodopa Responsiveness of Parkinson Disease

Background and Purpose: Parkinson disease (PD) is defined by its unique motor symptoms, where responsiveness to levodopa (L-DOPA) is fundamental for management. Recent research has highlighted a significant relationship between PD symptoms and glymphatic dysfunction. This study endeavors to clarify the connection between glymphatic system functionality and initial motor symptoms in PD, utilizing imaging biomarkers to determine its predictive capacity for L-DOPA responsiveness (LR). Materials and Methods: Retrospective study of 86 PD patients with 3.0-T MRI scans (July 2019 to March 2021), assessing the diffusion tensor image analysis along the perivascular space (DTI-ALPS) methods, enlarged perivascular spaces (ePVSs) load, and choroid plexus volume (CPV). Analyzed metrics versus the third part of the Unified Parkinson Disease Rating Scale (UPDRSIII) scores and %LR using linear regression, creating a %LR prediction model for the L-DOPA challenge. Explored relationships with age, sex, Hoehn and Yahr stage, Montreal Cognitive Assessment scores, and Mini-Mental State Examination score. Examined DTI-ALPS index, ePVSs, and CPV interrelations. Results: Pre-L-DOPA, UPDRSIII inversely correlated with DTI-ALPS index ( P =0.049), positively with bilateral basal ganglia ePVSs ( P <0.001). Age-adjusted BG-ePVSs-UPDRSIII link ( P <0.001). Post-L-DOPA, UPDRSIII correlated similarly and CPV was positive. %LR positively linked to DTI-ALPS index ( P <0.001), negatively to BG-ePVSs ( P =0.04), CPV ( P <0.001). Adjusted %LR-DTI-ALPS index positive ( P =0.005), %LR-CPV negative ( P =0.04). DTI-ALPS index, CPV predicted LCT outcomes (%LR ≥33%) with area under the curves 0.78, 0.79; accuracies 86.01%, 81.4%. The combined model area under the curve is 0.82, with an accuracy of 87.2%. Significant linear correlations were observed (CPV-DTI-ALPS, CPV-ePVSs, DTI-ALPS-ePVSs). Conclusions: A study affirms the link between glymphatic impairment, motor symptoms, and L-DOPA responses in PD. As glymphatic function declines, symptoms worsen, and L-DOPA effectiveness diminishes. The DTI-ALPS index and CPV emerge as potential predictors of PD patient LCT outcomes.