Age effects on the temporal evolution of isometric and swallowing pressure

Background. The tongue plays a key role in bolus propulsion through the oro pharyngeal chamber. In this study, possible age effects on the magnitude an d timing of lingual pressure generation were analyzed. Methods. Oral pressure was measured during isometric and swallowing tasks f or 10 elderly (mean age = 81 years) and 10 young (mean age = 51 years) subj ects. Three trials each of the isometric task and swallows of three differe nt boluses (3 mi semisolid, 3 mi liquid, and 10 mi liquid) were performed b y each subject. The timing and magnitude of isometric and swallowing pressu re generation along with the pattern of the swallowing pressure waveform we re analyzed. Results. Whereas maximum lingual isometric pressures decreased with age (p < .001), no significant age difference was found for swallowing pressure. T ime taken to reach peak pressure also was reduced with age in both the isom etric task and swallows of liquid boluses (p < .05), while no significant a ge 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 bu ilding"), a pattern demonstrated by both young and elderly groups for semis olids. Conclusions. Decreased lingual strength with age combined with unchanging s wallowing pressure leads to a decreased "pressure reserve," perhaps leaving older individuals more at risk for dysphagia resulting from insults direct ly or indirectly to the swallowing system. Additionally, swallowing is gene rally "slowed" with age, apparently due to both central and peripheral fact ors, and this change may have an impact on bolus flow outcomes.