From iRBD to Parkinson’s disease: Tracking Glymphatic Dysfunction Using Automated DTI-ALPS Analysis

This is the authors' abstract. We don't add key points for this paper.

Diffusion tensor image analysis along the perivascular space (DTI-ALPS) is a non-invasive marker of glymphatic function that typically relies on manual region of interest (ROI) placement. This study compared glymphatic function in treatment-naïve, de novo diagnosed patients with Parkinson’s disease (PD), patients with isolated REM behavior disorder (iRBD), and healthy controls using both manual and automatic DTI-ALPS methods. ALPS scores were analyzed bilaterally and correlated with clinical severity (MDS-UPDRS) and nigrostriatal denervation (DAT-SPECT). The study included 79 PD patients (60±12 years), 57 iRBD patients (67±7 years), and 48 controls (62±10 years). ANCOVA revealed significant inter-group differences using both manual (p=0.018) and automatic (p=0.002) methods. Automatic analysis showed significantly lower ALPS scores in PD compared to controls (p=0.001) and iRBD (p=0.009). ALPS scores correlated with symptom severity and nigrostriatal degeneration. These findings highlight early glymphatic dysfunction in PD and demonstrate the reliability of the automatic DTI-ALPS method.