Relationship between sialorrhea and dysphagia in Chinese patients with Parkinson's disease

Abstract

Objective To explore the prevalence of sialorrhea and its clinical correlation with dysphagia in Chinese patients with Parkinson's disease (PD). Methods One hundred and sixteen consecutive patients with a clinical diagnosis of PD were selected. Demographic data included sex, age, years of education, age at onset of PD, clinical genotype, disease duration, treatment, Hoehn and Yahr (H&Y) stage. Sialorrhea was assessed using the Unified Parkinson's Disease Rating Scale (UPDRS) Ⅱ item number 6. All patients were studied with videofluoroscopic study of swallowing (VFSS). Results The prevalence rate of sialorrhea in PD was 59.5% (69/116, 95% CI 50.6%-68.4%). Males were more likely to develop sialorrhea than females (47/70 vs 22/46, χ2=4.298, P=0.038). PD patients' sialorrhea correlated with oral dysphagia: with food leaking from the mouth (liquid r=0.229, P=0.014; juice r=0.197, P=0.034; pudding viscosities r=0.231, P=0.013; solid food r=0.255, P=0.006), with more than 1 ml of oral food residues (liquid r=0.319, P<0.01; solid food r=0.185, P=0.047), with delay in food transfer to the root of the tongue (liquid r=0.279, P=0.002; juice r=0.209, P=0.024), and delayed swallow transfer (pudding viscosities r=0.257, P=0.005). Sialorrhea score was not related to H&Y stage, clinical course and levodopa equivalent doses (LED). The prevalence rate of dysphagia in PD was 87.1% (95% CI 81.0%-93.2%). Liquid was more likely to cause pharyngeal dysphagia (P=0.03). With the increase in H&Y stage, so did the oral and pharyngeal stages of dysphagia. Late and mid-course was more likely to develop oral and pharyngeal dysphagia than those with early clinical course. Conclusions Sialorrhea and dysphagia are common non-motor symptoms in PD patients. Sialorrhea is more prevalent in males and correlates with oral phase of dysphagia. Liquid is more likely to cause pharyngeal dysphagia. With increase in H&Y stage, so did oral and pharyngeal dysphagia. Even though late clinical course is more likely to develop oral and pharyngeal dysphagia than early clinical course, the comparison between late and intermediate clinical courses does not reach statistical significance. Key words: Parkinson's disease; Sialorrhea; Dysphagia; Videofluoroscopic study of swallowing