高齢者と気管食道科 高齢者のえん下機能

Abstract

Swallowing is one of the most basic of the behaviors needed to sustain life. Clarification of swallowing mechanisms in the elderly is essential from the viewpoint of the prevention and treatment of dysphagia. In the second stage of the act of swallowing, the afferent nerve fibers of the internal branch of the superior laryngeal nerve (SLN), which innervate the pharyngeal and supralaryngeal mucosa, are concentrated in the interstitial subnucleus (ni) of the nucleus solitarius. In senile patients, presynaptic nerve fibers responded to chemostimulation, such as pure water, and/or a pressure stimulus from a limited area of the base of the epiglottis, aryepiglottic folds and arytenoid region. Furthermore, cortical evoked potentials were recorded at the frontal part of the orbital gyrus bilaterally after stimulating the SLN. In this study, subjects over the age of 65 were recruited for analysis of their swallowing mechanisms using a newly devised manometric measuring apparatus for the oropharynx, hypopharynx and respiratory phases. The results were as follows: 1) The oro-pharyngeal coupling time (OPCT) was defined as the period (msec) from the production of the final pressure peak in the oropharyngeal propelling force to the maximum pressure peak in the hypopharynx during swallowing. In the elderly, this OPCT was prone to prolongation over 420msec. 2) The second purpose of this study was to correlate standard parameters from the viewpoint of videofluorescent analysis with the qualitative characteristics of liquid and semi-solid bolus transport in the elderly. This investigation was carried out by measuring individual viscosities of variable radio-opaque materials for use in angiography using a viscosi-meter. Viscosity was calculated as the shear stress divided by the shear rate. In the elderly, it an incoordination in terms of coupling time was found between the conveyance of the bolus to the hypopharynx in the oropharynx and the closing of the laryngeal vestibule.