Quantitative evaluation of age-related alteration of swallowing function: Videofluoroscopic and manometric studies.

Objective: Swallowing function progressively deteriorates with advancing age, leading to high morbidity and mortality in the elderly population. To establish strategies for treatment of age-related swallowing disorders, the mechanisms of such disorders must be quantitatively clarified. The purpose of this paper was to elucidate the swallowing function of healthy elderly individuals by comparison with that of young adults by videofluorographic and manometric examinations.

Methods: The subjects were 70 healthy volunteers with no history of diseases affecting swallowing function. They were classified into three groups according to age: the young adult group (21-32 years of age, n=8), early elderly group (60-69 years of age, n=39), and late elderly group (70-83 years of age, n=23). Their swallowing functions were quantitatively evaluated by videofluorographic and manometric studies.

Results: Videofluorographic examination showed no significant differences in the moving distances of the hyoid bone and larynx in the pharyngeal swallowing phase between the young and elderly groups. The pharyngeal transit time (PTT) of the bolus in the elderly group was longer and the percentage of laryngeal elevation (%LE) was lower than those in the young group. Manometric examination revealed higher hypopharyngeal swallowing pressure in the elderly groups. The traveling velocity of the swallowing pressure in the upper esophageal sphincter (UES) region and the UES relaxation time decreased with aging. Reduction of the UES pressure during the pharyngeal swallowing phase was insufficient in 15.4% of the early elderly group and 30.4% of the late elderly group. Additionally, the UES zone was broadened in 20.5% of the early elderly group and 26.1% of the late elderly group.

Conclusion: Videofluorographic and manometric examinations quantitatively demonstrated that the swallowing reflex was delayed and UES opening was impaired by aging. UES dysfunction may develop secondary by increased tonicity and decreased elasticity of the cricopharyngeal muscle. Stimulation of oropharyngeal sensory function and exercising the laryngeal levator muscles may be effective for age-related swallowing disorders.