Impact of expiratory muscle strength training on swallowing function in Parkinson's disease: insights from high-resolution videomanometry.

INTRODUCTION: Expiratory Muscle Strength Training (EMST) is used for the rehabilitation of oropharyngeal dysphagia in patients with Parkinson's Disease (PD). MATERIALS & METHODS: Twenty individuals (16-men) with PD underwent High-Resolution Videomanometry (HRVM) before, during, and after training. RESULTS: Participants' mean age was 68.2 ± 8.5 years, with PD staging corresponding to Hoehn and Yahr stage 2 (1.0-3.6). Maximum Expiratory Pressure (MEP) was 79.2 ± 24 cmH2O. After training, there was an increase in laryngeal elevation and total displacement (10 mL nectar; r = 0.46, 95% CI [0.8, 8.8], p = 0.044 and r = 0.53, 95% CI [1.5, 5.9], p = 0.018, respectively). In addition, Intrabolus Pressure (IBP) increased during uncontrolled swallowing (nectar; r = 0.56, 95% CI [4.9, 18.6], p = 0.017). Moderate direct and inverse correlations were observed. A direct correlation was found between the Upper Esophageal Sphincter (UES) opening size and age (10 mL nectar; p = 0.037), and between laryngeal anteriorization and stage (10 mL nectar; p = 0.012). An inverse correlation was observed between UES opening size and MEP (10 mL pudding; p = 0.020). A direct correlation was observed between UES relaxation time and stage (10 mL nectar; p = 0.051), and between IBP during uncontrolled swallowing and stage (p = 0.008). The nadir of UES relaxation during uncontrolled swallowing showed a direct correlation with MEP (p = 0.031) and an inverse correlation with stage (p = 0.005). CONCLUSION: EMST influences laryngeal displacement. Disease stage, age, and MEP are relevant parameters that should be analyzed during PD rehabilitation. HRVM is a comprehensive tool for evaluating the impacts of EMST both during execution and on swallowing function in patients with PD.