Swallowing dysfunction in healthy older people using pharyngeal pressure-flow analysis

Background: Age-related loss of swallowing efficiency may occur for multiple reasons. Objective assessment of individual dysfunctions is difficult and may not clearly differentiate these from normal. Pharyngeal pressure-flow analysis is a novel technique that allows quantification of swallow dysfunction predisposing to aspiration risk based on a swallow risk index (SRI). In this study, we examined the effect of ageing on swallow function. Methods: Studies were performed in 68 healthy subjects aged 20-91 years (mean 59 years; 29 male), asymptomatic for oropharyngeal disease. Swallowing of liquid and viscous boluses was recorded with a pressure-impedance catheter. Indices of swallow function including the SRI, postswallow residues, upper esophageal sphincter opening and bolus transit time were derived using purpose designed software. Key Results: Swallow function worsened with increasing age with a significant decline after 80 years. Higher SRI correlated with increasing age (r = 0.257, p < 0.05 for liquids and r = 0.361, p < 0.005 viscous bolus). Subjects over 80 years were overrepresented amongst those with an SRI considered diagnostically relevant (SRI > 15). In addition, upper esophageal sphincter opening was reduced and postswallow residues increased in older subjects. Conclusions & Inferences: Pharyngeal pressure-flow analysis reveals multiple functional abnormalities in older individuals. The higher SRI levels seen in asymptomatic elders possibly reflect a loss of functional reserve with ageing. Automated impedance manometry analysis of swallow function may allow the risk of developing disordered swallowing to be quantified numerically.