Longitudinal change in swallow function in patients with Parkinson's disease (PD)

ObjectiveParkinson's disease (PD) frequently involves dysphagia, yet real-world longitudinal data capturing its progression and response to clinical care remain limited. Most prior studies exclude treated patients or rely solely on subjective or cross-sectional data. This study investigates long-term changes in swallowing physiology and diet in a pragmatic, treated PD population.MethodsWe retrospectively reviewed patients with PD who underwent at least two videofluoroscopic swallow studies (VFSS) ≥ 1 year apart at a tertiary laryngology center. Individuals with comorbid neurologic or structural disease were excluded. Standardized metrics included the Dynamic Imaging Grade of Swallowing Toxicity (DIGEST), Penetration Aspiration Scale (PAS), Functional Oral Intake Scale (FOIS), and International Dysphagia Diet Standardization Initiative (IDDSI), with kinematic analysis of Pharyngeal Constriction Ratio (PCR) and Maximum Pharyngoesophageal Segment Opening (PESmax). Ordinal outcomes were compared using Wilcoxon signed-rank tests; kinematic changes were analyzed with paired <i>t</i>-tests.ResultsNineteen patients (mean age 79.4 years, 73% male) completed 38 VFSS over a mean 2.6-year interval. Despite an average of 9.7 swallow therapy sessions per patient, significant declines were observed in PESmax (<i>p</i> < 0.001), DIGEST Overall (<i>p</i> = 0.024), Efficiency (<i>p</i> = 0.039), and IDDSI solids (<i>p</i> = 0.041). Subgroup analysis of mild-to-moderate PD (H&Y 1-3) showed similar trends.ConclusionSwallowing function deteriorates over time in PD, even with treatment. This study highlights the value of instrumental reassessment and supports proactive, longitudinal management in real-world care settings.