Isometric tongue endurance and incomplete laryngeal vestibule closure in Parkinson's disease

Dysphagia is a common symptom of Parkinson's disease (PD). A delay in laryngeal vestibule closure (LVC) and a reduction in tongue pressure, may affect swallowing safety and increase the risk of pulmonary aspiration.

To verify the relationship between tongue pressure and airway protection in PD patients: (1) comparing tongue pressure measures and physiological events in the pharyngeal phase of swallowing between PD and controls and (2) analysing the association between tongue pressure and LVC in the PD group.

Twenty-three patients with idiopathic PD (64.9 years) and 24 healthy controls (64.1 years) participated in this study. All participants underwent the following procedures to verify tongue pressure measurements using the Iowa Oral Performance Instrument: maximum anterior and posterior pressure, isotonic and isometric tongue endurance and anterior and posterior tongue pressure during saliva swallowing. To verify swallowing safety, videofluoroscopic swallowing studies focusing on the pharyngeal phase were performed based on the MBSImP protocol.

Compared to healthy controls, PD exhibited a statistically significant decline in tongue pressure tasks: posterior maximum pressure, isotonic endurance, anterior and posterior isometric endurance and tongue pressure during posterior swallowing. Patients with PD had worse pharyngeal scores, including LVC scores, than controls. PD and incomplete LVC had lower anterior isometric endurance scores when compared to those with complete LVC.

PD with incomplete LVC scored lower in the anterior isometric endurance task. We observed a potential clinical use of this task for the assessment and management of dysphagia in patients with PD.