ORIGINAL ARTICLE Variations in Tongue-Palate Swallowing Pressures When Swallowing Xanthan Gum-Thickened Liquids

The Author(s) 2014. This article is published with open access at Springerlink.com Abstract Thickened liquids are frequently recommended to reduce the risk of aspiration in patients with oropha-ryngeal dysphagia. Although it has previously been reported that tongue-palate pressures increase when swal-lowing spoon-thick and semi-solid consistencies compared to thin liquids, relatively little is known about how swal-lowing behaviors differ when swallowing liquids of nectar-or honey-thick consistency. Furthermore, previous studies have primarily used starch-based thickeners, and little is known about swallowing behaviors with xanthan gum-thickened liquids, which have recently been introduced for dysphagia management. In this study, we measured varia-tions in tongue-palate pressures during the swallowing of liquids thickened to apparent viscosities of 190, 250, and 380 mPa s at 50/s using increasing concentrations of xan-than gum (0.5, 0.63 and 0.87 w/w%). The viscosity dif-ferences between these nectar- and honey-thick stimuli were confirmed to exceed sensory perceptual discrimina-tion thresholds. Data were collected from 78 healthy adults in two sex-balanced age-groups (young; mature) and compared to reference values obtained during water swallowing. The results confirm that increased amplitudes of tongue-palate pressure were used when swallowing the thickened liquid stimuli, compared to swallows of water, and for the honey-thick liquid compared to the two nectar-thick liquids. Age-related reductions were seen in tongue strength but not in swallowing pressures, which fell below 40 % of maximum isometric pressure values. Thus, the use of xanthan gum-thickened liquids is unlikely to tax the swallowing system in terms of tongue pressure generation requirements, even in seniors with reduced maximum isometric tongue pressure measures