Associations between Subjective Symptoms and Instrumental Dysphagia Measures in Parkinson's Disease

Dysphagia is a critical manifestation of Parkinson's disease (PD) contributing to morbidity and mortality. Although patient-reported measures are widely used for screening, concordance with objective impairment, particularly over time, remains uncertain.

The aim is to investigate cross-sectional and longitudinal associations between patient-reported swallowing symptoms and objective findings in PD.

We retrospectively analyzed 103 PD patients who underwent the Swallowing Disturbance Questionnaire (SDQ) and videofluoroscopic swallowing study. The Videofluoroscopic Dysphagia Scale (VDS) quantified objective impairment. Longitudinal associations were examined in 24 patients (39 paired observations) over a median follow-up of 1.2 years. Multivariable and linear mixed-effects models were used for adjusting age, sex, disease duration, and Hoehn and Yahr scale.

Cross-sectional analysis demonstrated a significant association between total SDQ and VDS scores (β = 1.18, P < 0.001), with a stronger relationship in pharyngeal (β = 1.32) than oral domain (β = 0.71). Higher SDQ scores correlated with lower American Speech-Language-Hearing Association National Outcomes Measurement System (ASHA NOMS) levels [odds ratio (OR) = 0.95, P = 0.010]. Changes in SDQ scores were significantly associated with changes in VDS scores in longitudinal analysis (total: β = 0.78; oral: β = 0.67; pharyngeal: β = 0.75).

In the clinically referred cohort of PD patients, SDQ scores were associated with the severity and within-person changes of objective swallowing impairment. Although not replacing instrumental assessments, SDQ may help track progression and identify the need for further evaluation. Larger prospective studies are needed to clarify the role of patient-reported measures in long-term dysphagia monitoring in PD.