Fei T, Polacco RC, Hori SE, Molfenter SM, Peladeau-Pigeon M, Tsang C, Steele CM.
Dysphagia. 2013 May 16.
The tongue plays a key role in the generation of pressures for transporting liquids and foods through the mouth in swallowing. Recent studies suggest that there is an age-related decline in tongue strength in healthy adults. However, whether age-related changes occur in tongue pressures generated for the purpose of swallowing remains unclear. Prior literature in this regard does not clearly explore the influence of task on apparent age-related differences in tongue pressure amplitudes. Furthermore, differences attributable to variations across individuals in strength, independent of age, have not clearly been elucidated. In this study, our goal was to clarify whether older adults have reduced tongue–palate pressures during maximum isometric, saliva swallowing, and water swallowing tasks, while controlling for individual variations in strength. Data were collected from 40 healthy younger adults (under age 40) and 38 healthy mature adults (over age 60). As a group, the mature participants had significantly lower maximum isometric pressures (MIPs). Swallowing pressures differed significantly by task, with higher pressures seen in saliva swallows than in water swallows. Age-group differences were not seen in swallowing pressures. Consideration of MIP as a covariate in the analysis of swallowing pressures revealed significant correlations between strength and swallowing pressures in the older participant group. Age-group differences were evident only when strength was considered in the model, suggesting that apparent age-related differences are, in fact, explained by differences in strength, which tends to be lower in healthy older adults. Our results show no evidence of independent differences in swallowing pressures attributable to age.
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Nagy A, Leigh C, Hori SF, Molfenter SM, Shariff T, Steele CM.
Dysphagia. 2013 Mar 1
Temporal parameters such as stage transition duration, bolus location at swallow onset, and pharyngeal transit time are often measured during videofluoroscopy, but these parameters may vary depending on assessment instructions. Specifically, “command” (cued) swallows have been observed to alter timing compared to spontaneous (noncued) situations in healthy older adults. The aim of our study was to confirm whether healthy young people show timing differences for thin liquid swallows between cued and noncued conditions. Twenty healthy young adults swallowed 10-cc boluses of ultrathin barium in videofluoroscopy. The cued condition was to hold the bolus in the mouth for 5 s before swallowing. Three noncued swallows were also recorded. In the cued condition, bolus advancement to the pyriform sinuses prior to swallow initiation was seen significantly less frequently. Stage transition durations showed a nonsignificant trend toward being shorter. Pharyngeal transit times and pharyngeal response time (a measure capturing the interval between hyoid movement onset and bolus clearance through the upper esophageal sphincter) were both significantly longer in the cued condition. Our study in healthy young adults confirms findings previously observed in older adults, namely, that swallow onset patterns and timing differ between cued and noncued conditions. In particular, bolus advancement to more distal locations in the pharynx at the time of swallow onset is seen more frequently in noncued conditions. This pattern should not be mistaken for impairment in swallow onset timing during swallowing assessment.
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Fakhry N, Puymerail L, Michel J, Santini L, Lebreton-Chakour C, Robert D, Giovanni A, Adalian P, Dessi P.
Dysphagia. 2013 Feb 28.
The aim of this study was to obtain a quantitative anatomical description of the hyoid bone using modern 3D reconstruction tools and to discuss potential applications of the knowledge in clinical practice. The study was conducted on 88 intact hyoid bones taken from cadavers during forensic autopsies (group 1) and on 92 bones from CT scan images of living adult subjects (group 2). Three-dimensional reconstructions were created from CT scan images using Amira 5.3.3® software. An anatomical and anthropological study of hyoid bones was carried out using metric and morphological analyses. Groups 1 and 2 were compared to evaluate the influence of muscle traction on hyoid bone shape. Characteristics of the hyoid bone were highly heterogeneous and were closely linked with the sex, height, and weight of the individuals. Length and width were significantly greater in men than in women (39.08 vs. 32.50 mm, p = 0.033 and 42.29 vs. 38.61 mm, p = 0.003), whereas the angle between the greater horns was larger in females (44.09 vs. 38.78, p = 0.007). There was a significant positive correlation between the height (Pearson coefficient correlation r = 0.533, p = 0.01) and weight (r = 0.497, p = 0.01) of subjects and the length of the hyoid bone. Significant metric differences were shown between group 1 and group 2. This very reproducible methodology is important because it may lead to clinical studies in, e.g., head and neck cancer or sleep apnea. Such studies are ongoing in our research program.
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Ianessa A. Humbert, Rebecca Z. German
Oropharyngeal swallowing is a complex sensorimotor phenomenon that has had decades of research dedicated to understanding it more thoroughly. However, the underlying neural mechanisms responsible for normal and disordered swallowing remain very vague. We consider this gap in knowledge the result of swallowing research that has been broad (identifying phenomena) but not deep (identifying what controls the phenomena). The goals of this review are to address the complexity of motor control of oropharyngeal swallowing and to review the principles of motor learning based on limb movements as a model system. We compare this literature on limb motor learning to what is known about oropharyngeal function as a first step toward suggesting the use of motor learning principles in swallowing research.
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Dysphagia. 2011 Sep;26(3):238-45. doi: 10.1007/s00455-010-9292-2. Epub 2010 Jul 27.
Hori K, Tamine K, Barbezat C, Maeda Y, Yamori M, Müller F, Ono T.
The purpose of this study was to investigate the influence of chin-down posture and bolus size on tongue pressure during swallowing. Eleven healthy volunteers (7 men, 4 women; age range = 26-59 years) participated in the experiments. Tonguepressure during dry and 5- and 15-ml water swallows in neutral and chin-down postures was measured using a sensor sheet system with five measuring points on the hard palate. Sequential order, maximal magnitude, duration, and integrated value oftongue pressure at each measuring point were compared between postures and bolus sizes. Onset of tongue pressure at posterior-circumferential parts occurred earlier in dry swallow than in 5- and 15-ml water swallows in each posture. Chin-down posture was most effective for increasing tongue pressure in the 5-ml water swallow compared with dry swallow and the 15-ml water swallow, but it had almost no influence on tongue pressure with the 15-ml water swallow. These results suggest that chin-down posture increases the tongue driving force for small boluses in healthy subjects, which can be interpreted to mean that oropharyngeal swallowing in a chin-down posture requires more effort.
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