A cross-sectional study of autonomic dysfunction in patients with Parkinson's disease and vascular parkinsonism

This study aimed to evaluate autonomic function differences between Parkinson's disease (PD) and vascular parkinsonism (VP) for improved differential diagnosis. A total of 120 patients (60 PD, 60 VP) underwent comprehensive autonomic assessments, including skin scratch test, oculocardiac reflex, postural heart rate changes, heart rate variability (HRV), and 24-hour urinary vanillylmandelic acid (VMA). Disease severity was measured using MDS-UPDRS and Hoehn-Yahr staging in PD and NIHSS in VP. Results demonstrated significantly more severe autonomic impairment in PD across all measures (all P < 0.001). Subgroup analyses showed greater dysfunction in female PD patients and those with advanced disease, with strong correlations between disease duration and severity (rho > 0.80). In VP, autonomic abnormalities were milder and showed no sex-related differences. ROC analysis identified six autonomic indices with high discriminative power (AUC 0.94-0.99). A composite score incorporating red streak duration, HRV, and VMA effectively distinguished PD from VP. These findings indicate that PD is characterized by more extensive autonomic dysfunction than VP, influenced by disease progression and sex. The developed autonomic function score provides a practical, non-invasive tool for differential diagnosis, facilitating individualized management of these parkinsonian disorders.