Role of laryngeal movement and effect of aging on swallowing pressure in the pharynx and upper esophageal sphincter

Objectives: Describe contribution of laryngeal movement to pressure changes at the upper esophageal sphincter (UES) and the effect of aging on the swa llowing function Study Design: Manofluorography an 56 nondysphagic adults d ivided into three age groups: the 21- to 31-year-old group (n = 32), the 61 - to 74-years-old group (n = 12) and the 75- to 89-year-old group (n = 12). Analyses of the bolus transit time, the amplitudes and durations of pharyn geal pressures, the timing of a pressure fall at the UES and the laryngeal movements. Methods: Intraluminal strain-gauge sensors recorded pressure cha nges in the oropharynx, hypopharynx and the UES. Motion pictures of the vid eotapes were fed into a personal computer, and movements of the hyoid bone were measured in both the horizontal and vertical directions as an indicati on of laryngeal movement. Results: In 26- and 70-year-old men with calcific ation of the thyroid cartilage, it was determined that the larynx and hyoid bone moved in consonance until the end of the rapid hyoid movements in bot h the superior and anterior directions. In the 21- to 31-year-old group, th e magnitude of the pressure fall at the UES was maximal before or almost at the same time as the bolus arrival, in preparation for smooth passage of t he bolus from the pharynx to the esophagus. The rapid superior movements of the hyoid bone started significantly early as compared with its anterior m ovements (P =.0001). The rapid anterior movements of the hyoid bone started simultaneously with the pressure fall at the UES. In the elderly, all segm ental transit times mere significantly increased. The timing of the pressur e fall at the UES was significantly delayed and the UES pressure reached it s minimum value after arrival of the bolus at the UES. The minimum pressure at the UES increased to a significantly positive value. The rapid anterior movements of the hyoid were significantly delayed, suggesting that this de lay causes the delay in the pressure fall at the UES. Conclusions: The rapi d superior and anterior movements of the hyoid bone are considered to start at the same time as those of the larynx. In the young group, it is suggest ed that superior laryngeal movement protects the lower airway prior to the anterior laryngeal movement, causing the pressure fall at the UES to enable the passage of a bolus into the UES, In the elderly, smooth passage of the bolus from the pharynx to the esophagus is hindered and the system that pr events aspiration is rendered inefficient by changes in the swallowing pres sures and laryngeal movements with aging.