Age Effects on the Temporal Evolution of Isometric and Swallowing Pressure

TLDR

The tongue is essential for bolus propulsion in the oropharyngeal chamber, and swallowing is generally slowed with age due to central and peripheral factors, potentially affecting bolus flow outcomes. The study examined age effects on the magnitude and timing of lingual pressure generation during isometric and swallowing tasks in 10 elderly and 10 young adults. The authors measured oral pressure during isometric and swallowing tasks, performing three trials per task and three bolus types (3 ml semisolid, 3 ml liquid, 10 ml liquid) per subject, and analyzed timing, magnitude, and waveform patterns. Maximum lingual isometric pressures were significantly lower in elderly subjects, while swallowing pressures did not differ by age; however, elderly individuals reached peak pressure faster during isometric tasks and liquid swallows, exhibited a pressure‑building pattern requiring multiple lingual gestures for liquid swallows, and the combination of reduced lingual strength and unchanged swallowing pressure may diminish pressure reserve and increase dysphagia risk.

Abstract

The tongue plays a key role in bolus propulsion through the oropharyngeal chamber. In this study, possible age effects on the magnitude and timing of lingual pressure generation were analyzed.Oral pressure was measured during isometric and swallowing tasks for 10 elderly (mean age = 81 years) and 10 young (mean age = 51 years) subjects. Three trials each of the isometric task and swallows of three different boluses (3 ml semisolid, 3 ml liquid, and 10 ml liquid) were performed by each subject. The timing and magnitude of isometric and swallowing pressure generation along with the pattern of the swallowing pressure waveform were analyzed.Whereas maximum lingual isometric pressures decreased with age (p < .001). no significant age difference was found for swallowing pressure. Time taken to reach peak pressure also was reduced with age in both the isometric task and swallows of liquid boluses (p < .05), while no significant age effect was found for semisolid swallows. Finally, only elderly subjects showed a pattern of liquid swallowing pressure generation in which multiple lingual gestures were required to reach peak pressure (termed "pressure building"), a pattern demonstrated by both young and elderly groups for semisolids.Decreased lingual strength with age combined with unchanging swallowing pressure leads to a decreased "pressure reserve," perhaps leaving older individuals more at risk for dysphagia resulting from insults directly or indirectly to the swallowing system. Additionally, swallowing is generally "slowed" with age, apparently due to both central and peripheral factors, and this change may have an impact on bolus flow outcomes.