INFLUENCE OF AGING ON ORAL-PHARYNGEAL BOLUS TRANSIT AND CLEARANCE DURING SWALLOWING - SCINTIGRAPHIC STUDY

The aim of the study was to determine the influence of normal aging on regional transit and the efficiency of bolus clearance during the ora l and pharyngeal phases of swallowing. We compared scintigraphically d erived oral-pharyngeal transit times and isotope clearance during swal lowing in 21 healthy aged volunteers (mean age 68 +/- 8 yr) and 9 youn g controls (mean age 28 +/- 7.5 yr). Subjects swallowed 5- and 10-ml w ater boluses mixed with 30 MBq (99m)technetium tin colloid. Oral and p haryngeal transit times, pharyngeal clearance time, and postswallow re sidual counts in each region were derived from time-activity curves. P haryngeal residual counts were significantly greater in the aged than in controls (P = 0.0008), but age did not influence oral residual. Agi ng significantly prolonged oral transit time (P = 0.02), pharyngeal tr ansit time (P = 0.0004), and pharyngeal clearance time (P = 0.0001). W e conclude that normal aging impairs the efficiency of pharyngeal clea rance during swallowing, prolongs scintigraphic measures of oral-phary ngeal transit, and increases the exposure time of the glottis to the s wallowed bolus.