A handy manometric evaluation of swallowing-related tongue function

Objectives: The tongue plays a key role in bolus propulsion through the oropharyngeal chamber. This study aims to clarify whether tongue function quantified by measuring the swallowing pressure is related to swallowing function or not.

Methods: Healthy volunteers without the history of the cerebrovascular accident and the neuromuscular disease (n=452, 63.1±18.5 years) participated in the study and were divided into two groups (healthy group and risk group for swallowing function) by using Repetitive Saliva Swallowing Test (RSST) and Water Swallowing Test (WST) as screening tests of dysphagia. In healthy group, subgroups were established by gender and age (young group 18-39 years, middle group 40-64 years, young-old group 65-74 years and old-old group 75-89 years). Using our prototyped portable device for tongue pressure measurement, functional parameters including maximum voluntary tongue pressure (MVTP), maximum swallowing tongue pressure (MSTP), pressure reserve (=MVTP-MSTP), duration of tongue pressure, number of pressure spikes and time integrated value of swallowing pressure for a single 5 ml water swallowing. The effect of gender, age and swallowing function on these parameters were examined.

Results: No statistical difference was found between male and female volunteers. Pressure reserve decreased along with age (p<0.05, ANOVA), while number of pressure spikes and duration of tongue pressure increased (p<0.05, ANOVA). Number of pressure spikes, duration of tongue pressure and time integrated value of swallowing pressure were significantly related to the evaluation of swallowing function (p<0.05, logistic regression).

Conclusions: Age and swallowing function were related to the swallowing pressure. Measuring swallowing tongue pressure may be an effective method for quantitative evaluation of swallowing function.