Characteristics of Swallowing Function in People with Parkinson's Disease: A Scoping Review

BACKGROUND Most individuals with Parkinson's disease (PD) develop dysphagia during the course of their disease. It is crucial to comprehensively understand swallowing characteristics specific to PD for effective treatment.

OBJECTIVES To systematically analyze and synthesize swallowing characteristics in people with PD compared with healthy controls and to summarize the assessment methods used.

METHODS This scoping review was conducted in accordance with the Joanna Briggs Institute's (JBI) methodology. Systematic searches were conducted across six databases and one clinical trial registry. Original research articles reporting swallowing characteristics in cohorts comprising at least three individuals with PD were included. Studies published in English or German from the inception of the databases up to February 2024 were considered for inclusion. Independent reviewers assessed articles for eligibility and extracted relevant data. The scoping review protocol was registered and published (Open Science Framework, https://osf.io/8b3hm). Swallowing characteristics and assessment methods were systematically categorized. Significant characteristics, consistent across at least two studies, were included in the final analysis.

RESULTS Analysis included 46 studies with 1797 PD participants aged 35-85 years. Nineteen distinct oropharyngeal swallowing characteristics in individuals with PD were identified. Instrumental assessments (39/46, 85%), clinical assessments (10/46, 22%), and patient-related outcome measures (PROMs) (7/46, 15%) were used.

CONCLUSIONS Relevant swallowing abnormalities in PD can largely be interpreted as manifestations of bradykinesia, hypokinesia, and akinesia, supporting the view that dysphagia in PD constitutes a complex motor syndrome. Future research should aim to better characterize the manifestations within this syndrome and elucidate its underlying pathology. © 2026 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.