Abstract
BACKGROUND: Dysphagia in Parkinson's disease (PD) is a common manifestation, particularly in advanced disease stages. However, the pathophysiology and time course of dysphagia progression remains unclear in non-advanced disease stages (e.g., Hoehn & Yahr stages I-III). Conflicting reports from investigations of the perception of dysphagia in people with PD further complicates our understanding of dysphagia in this population. OBJECTIVE: The objectives of this research were to evaluate the ability of screening tools to detect swallowing impairments and how laryngeal kinematics predict the occurrence of abnormal swallowing events. METHODS: 14 individuals with non-advanced PD, no previous history of dysphagia diagnosis, and self-reported difficulty swallowing participated. The Swallow Disturbance Questionnaire (SDQ) and 3-oz water swallow test (WSST) were administered, along with a videoflouroscopic swallow study (VFSS). Laryngeal kinematics were represented by laryngeal vestibule closure reaction time (LVrt) and laryngeal vestibule closure duration (LVCd). The Penetration-Aspiration Scale (PAS) was used to quantify airway invasion. RESULTS: A logistic regression indicated a significant model of predicting airway invasion from our predictors (p = 0.003). LVrt and SDQ (p < 0.05) provided the largest impact (OR = 1.11; 1.17). The WSST showed no significance in predicting swallow impairment (p > 0.05). CONCLUSION: Decreased airway safety related to laryngeal kinematic function in PD may be manifesting at non-advanced disease stages to varied degrees. Our results support expectations of dysphagia manifestation in PD although screening practices may not adequately identify impairment. Future research should target specific laryngeal characteristics within this population to better understand the physiological cause of swallowing impairment and developof targeted interventions.