Objective: To examine factors associated with drooling in patients with Parkinson’s disease (PD), patient awareness and perceptions of botulinum toxin therapy, and the relative contributions of autonomic dysfunction and dysphagia.
Background: Chronic sialorrhea is common in PD, yet its clinical correlates and patient awareness of approved treatments remain unclear.
Method: We conducted a questionnaire study of consecutive PD outpatients at Keio University Hospital (October–December 2025). Drooling was defined using MDS-UPDRS Part II item 2 (very mild to severe). Autonomic symptoms were assessed with SCOPA-AUT and swallowing with the Swallowing Disturbances Questionnaire (SDQ). Clinical variables and 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy indices were abstracted from records. K-means clustering (k=3) was performed among droolers using standardized SCOPA-AUT total scores and SDQ scores.
Results: Among 208 patients, 116 (55.8%) were droolers. Droolers were more often male and had longer disease and treatment duration, higher Hoehn & Yahr stage, higher levodopa equivalent daily dose, higher SDQ scores, and greater autonomic symptom burden, which remained higher even after exclusion of the drooling-related SCOPA-AUT item. Droolers also had lower early and delayed MIBG heart-to-mediastinum ratios. Only 34.5% of droolers perceived a drooling problem; 14.7% were aware of botulinum toxin therapy; 21.6% were willing to receive injections. Clustering identified three phenotypes: low autonomic/low dysphagia, high autonomic/high dysphagia, and high autonomic/low dysphagia.
Conclusion: Chronic sialorrhea in PD is associated with male sex, greater motor severity, higher dysphagia burden, and broader autonomic dysfunction. Patients’ low awareness of drooling and botulinum toxin therapy highlights the need for systematic screening and education. Cluster-derived phenotypes may facilitate more personalized management.
To cite this abstract in AMA style:
S. Okusa, R. Okochi, Y. Sakai, T. Nukariya, Y. Nihei, J. Nakahara, M. Seki. Clinical and Autonomic Correlates of Chronic Sialorrhea in Parkinson’s Disease: A Questionnaire-Based Study with Cluster Analysis of Autonomic and Dysphagia Burden [abstract]. Mov Disord. 2026; 41 (suppl 1). https://www.mdsabstracts.org/abstract/clinical-and-autonomic-correlates-of-chronic-sialorrhea-in-parkinsons-disease-a-questionnaire-based-study-with-cluster-analysis-of-autonomic-and-dysphagia-burden/. Accessed October 1, 2026.« Back to 2026 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/clinical-and-autonomic-correlates-of-chronic-sialorrhea-in-parkinsons-disease-a-questionnaire-based-study-with-cluster-analysis-of-autonomic-and-dysphagia-burden/