Quantitative lingual, pharyngeal and laryngeal ultrasonography in swallowing research: a technical review

Methodological Procedures to Acquire and Analyze Ultrasound Images of Swallowing: A Scoping Review

This scoping review aimed to identify methodological procedures for acquiring and analyzing ultrasound images related to swallowing in adults and older adults. The inclusion criteria were based on the PCC strategy (participants, concept, and context), as follows: population (adults and older adults), concept (ultrasound assessment), and context (swallowing assessment). The review included observational, experimental, descriptive, and analytical studies and excluded those that were not available in full, animal studies, in vitro studies, letters to the editor, errata, study protocols, and those that used ultrasound for purposes other than swallowing. There were no language and time restrictions. Two independent blinded professionals selected 81 articles that met the inclusion criteria from different databases. The most evaluated parameters included tongue morphology and movements, hyoid bone displacement, swallowing muscle area, and pharyngeal residue detection, such as pharyngeal wall mobility. They used convex and linear transducers (3 MHz to 8 MHz) positioned in the submental, laryngeal, and lateral regions of the neck. The subjects were seated and instructed to eat different food volumes and consistencies. The literature mapping showed that ultrasound is a promising diagnostic tool, helping clinicians understand swallowing disorders, as it provides static and dynamic images in different modes and positions. Also, patients receive real-time biofeedback of changes related to dysphagia.

Application of Ultrasonography in Neurogenic Dysphagia: A Systematic Review

Swallowing disorders are common in neurological diseases, with dysphagia representing one of the most prevalent complications that may cause poor quality of life, reduce independence, and increase mortality. Rapid identification of dysphagia is necessary to reduce the risk of penetration and aspiration, and to early start rehabilitation protocols. Among the methods that can be used to evaluate dysphagia and its components, ultrasound imaging has been suggested to support the evaluation of dysphagia by providing measures of both static and dynamic anatomical components. The aim of this systematic review is to evaluate the usefulness of ultrasonography in neurogenic dysphagia according to current literature. From 2000 to 2020, 633 studies with the appropriate search terms for ultrasound and dysphagia were identified. After screening them, 10 studies were included in the qualitative analysis. Patients with the following neurologic conditions were studied with ultrasonography for dysphagia: Parkinson's disease, muscle dystrophy, amyotrophic lateral sclerosis, and stroke. The main outcomes of ultrasonography were swallowing muscles thickness (e.g., tongue), and dynamic measures such as hyoid displacement. The different protocols used in the studies, as well as their outcomes, did not allow to provide standard procedures and normative or cut-off values in the presented diseases. Because there are a variety of tools, methods, and techniques that have been used in the studies that were reviewed, it is difficult to evaluate them using established standards. However, ultrasonography correlates well with clinical evaluation of dysphagia and therefore has prognostic and rehabilitation potential. Future studies should aim to develop and utilize a common interdisciplinary protocol that includes standard procedures and outcomes to define normative values applicable in the different conditions.

Emerging Role of Ultrasound in Dysphagia Assessment and Intervention: A Narrative Review

Ultrasonography has gained increasing attention as a non-invasive and radiation-free instrument for the assessment of swallowing function. In the past decades, an extensive repertoire of ultrasonographic techniques, such as, B-mode dynamic scanning, pixel analysis, M-mode, Doppler, 3D reconstruction, and sonoelastography, has been applied in the evaluation of oropharyngeal structures and movement. Yet, a universal consensus on the examination protocols and clinical implications remains to be established. This review aimed to provide a brief introduction of the application of ultrasound in dysphagia assessment and intervention, encompassing the ultrasonography of swallowing-related muscles, tongue movement, and hyolaryngeal excursion, as well as ultrasound-guided interventions in the management of dysphagia. In addition to non-invasiveness, ultrasonography, a portable, easy to use, and low-cost technique, could compliment videofluoroscopic swallowing study as a first-line screening and follow-up tool for the evaluation of swallowing function, although further study is warranted to provide quantitative diagnostic and prognostic values. Finally, ultrasonography aids in the precisely targeted injection of botulinum toxin in patients exhibiting oropharyngeal muscle spasticity.

Quantitative imaging of tongue kinematics during infant feeding and adult swallowing reveals highly conserved patterns

Tongue motility is an essential physiological component of human feeding from infancy through adulthood. At present, it is a challenge to distinguish among the many pathologies of swallowing due to the absence of quantitative tools. We objectively quantified tongue kinematics from ultrasound imaging during infant and adult feeding. The functional advantage of this method is presented in several subjects with swallowing difficulties. We demonstrated for the first time the differences in tongue kinematics during breast- and bottle-feeding, showing the arrhythmic sucking pattern during bottle-feeding as compared with breastfeeding in the same infant with torticollis. The method clearly displayed the improvement of tongue motility after frenotomy in infants with either tongue-tie or restrictive labial frenulum. The analysis also revealed the absence of posterior tongue peristalsis required for safe swallowing in an infant with dysphagia. We also analyzed for the first time the tongue kinematics in an adult during water bolus swallowing demonstrating tongue peristaltic-like movements in both anterior and posterior segments. First, the anterior segment undulates to close off the oral cavity and the posterior segment held the bolus, and then, the posterior tongue propelled the bolus to the pharynx. The present methodology of quantitative imaging revealed highly conserved patterns of tongue kinematics that can differentiate between swallowing pathologies and evaluate treatment interventions. The method is novel and objective and has the potential to advance knowledge about the normal swallowing and management of feeding disorders.

Using ultrasound to characterize the tongue-food interface: An in vitro study examining the impact of surface roughness and lubrication

We measured the apparent reflection coefficient of a 1-MHz ultrasound compressional wave at the interface between rough and lubricated tongue mimicking surfaces and various food gels, composed of agar or gelatin. For the smoothest mimicking surface, when a lubricating layer was present, the apparent reflection coefficient was fairly similar for the different food gels (33.6% on average). The apparent reflection coefficient was significantly larger in the following situations: (i) tongue asperities were high and dense; (ii) lubrication levels were low; and (iii) gels were less rigid (range for the different gels-45.9-84.3%). The apparent reflection coefficient conveys the ability of food gels to mold themselves to surface asperities or to form a coupling film of liquid at the interface. This study demonstrates that ultrasound methods can and should be used to explore the physical phenomena that underlie the texture perceptions resulting from tongue-palate interactions.

Assessment of Tongue Position and Laryngeal Height in Two Professional Voice Populations

Purpose To advance our current knowledge of singer physiology by using ultrasonography in combination with acoustic measures to compare physiological differences between musical theater (MT) and opera (OP) singers under controlled phonation conditions. Primary objectives addressed in this study were (a) to determine if differences in hyolaryngeal and vocal fold contact dynamics occur between two professional voice populations (MT and OP) during singing tasks and (b) to determine if differences occur between MT and OP singers in oral configuration and associated acoustic resonance during singing tasks. Method Twenty-one singers (10 MT and 11 OP) were included. All participants were currently enrolled in a music program. Experimental procedures consisted of sustained phonation on the vowels /i/ and /ɑ/ during both a low-pitch task and a high-pitch task. Measures of hyolaryngeal elevation, tongue height, and tongue advancement were assessed using ultrasonography. Vocal fold contact dynamics were measured using electroglottography. Simultaneous acoustic recordings were obtained during all ultrasonography procedures for analysis of the first two formant frequencies. Results Significant oral configuration differences, reflected by measures of tongue height and tongue advancement, were seen between groups. Measures of acoustic resonance also showed significant differences between groups during specific tasks. Both singer groups significantly raised their hyoid position when singing high-pitched vowels, but hyoid elevation was not statistically different between groups. Likewise, vocal fold contact dynamics did not significantly differentiate the two singer groups. Conclusions These findings suggest that, under controlled phonation conditions, MT singers alter their oral configuration and achieve differing resultant formants as compared with OP singers. Because singers are at a high risk of developing a voice disorder, understanding how these two groups of singers adjust their vocal tract configuration during their specific singing genre may help to identify risky vocal behavior and provide a basis for prevention of voice disorders.

Presbyphagia Diagnostics Using M-Mode Ultrasound: Changes in the Tongue Movement Pattern

Age-related physiological changes of the swallowing act impair particularly the oral phase and the tongue function, which is very important for bolus preparation and transfer. At present, there are no easily applicable methods for measurement of this phase of swallowing. This study was designed to investigate the deglutitive tongue movement by M-mode ultrasound and to compare the collected parameters of different age groups. In this exploratory prospective study, the tongue and its movements of 20 younger and 30 older women were examined during swallowing by B-mode and M-mode ultrasound. Preexisting dysphagia or malnutrition as well as psychic or neurological deficits were excluded by clinical examination and screening with the Mini Nutritional Assessment-Short Form (MNA-SF), the Gugging Swallowing Screen (GUSS), the Mini-Mental State Examination (MMSE) and the Barthel Index. The data were compared with each other and statistically analyzed. With increasing age, a change in the tongue movement pattern becomes apparent. In the group of older women, the vertical lingual movement had a smaller amplitude (p < 0.001) and a shorter time to the maximum amplitude (p < 0.03) than in the group of younger women. However, there were no differences in the tongue diameter (p > 0.4). The tongue movement pattern appears to be subject to age-specific changes, in contrast to anatomy. The use of M-mode ultrasonography is an easy, radiation-free and cost-effective method for the assessment of the oral phase of swallowing. Limitations are the widely scattered values of the ultrasound findings. Further studies are needed for validation and definition of standard values for this promising method.

Effects of Capsaicin on Older Patients with Oropharyngeal Dysphagia: A Double-Blind, Placebo-Controlled, Crossover Study

BACKGROUND/AIMS

The standard of care for older patients with oropharyngeal dysphagia (OD) is poor. Stimulation of transient receptor potential vanilloid 1 might become a pharmacological strategy for these patients. This study aimed to compare the therapeutic effect of film food containing 0.75 µg of capsaicin in these patients.

METHODS

In a crossover, randomized trial, 49 patients with OD were provided capsaicin or identical placebo at least 7 days apart. Patients' reported symptoms during repeated swallowing, the volume, pH and substance P (SP) concentrations in saliva, and cervical esophageal wall motion evaluated by ultrasonographic tissue Doppler imaging were obtained before and after capsaicin or placebo administration.

RESULTS

Significantly more patients with OD who took capsaicin experienced improvement in symptoms than those who took placebo. Salivary SP levels were significantly increased after capsaicin administration compared with placebo in the effective group. The duration of cervical esophageal wall opening was significantly shorter in capsaicin administration in the effective group. Furthermore, a significant negative correlation was found between the duration of cervical esophageal wall opening and salivary SP levels.

CONCLUSION

Elevated salivary SP concentrations stimulated by capsaicin greatly improve the safety and efficacy of swallowing, and shorten the swallow response in older patients with OD.

New ultrasonographic screening method for oropharyngeal dysphagia: tissue Doppler imaging

Ultrasound tissue Doppler imaging (US-TDI) has been used to diagnose regional wall motion (WM) abnormalities in coronary artery disease but has not been applied to oropharyngeal diseases. This study aimed first to validate an US-TDI method to assess cervical esophageal (CE) WM and secondly to use the method to evaluate CE WM in patients with oropharyngeal dysphagia (OD). First, we enrolled 22 healthy men (mean age: 59.7 yr) who all underwent both US-TDI and videofluoroscopy (VF) and then esophageal high-resolution manometry (HRM) in the same week. We evaluated the reproducibility of the US-TDI and the relationship between US-TDI and other modalities (VF and HRM). Second, we enrolled 56 mild OD patients (mean age: 58.0 yr) and age- and sex-matched healthy controls. Difference in CE WM between these groups was evaluated by US-TDI. All healthy subjects underwent US-TDI, VF, and HRM successfully, with a sufficiently high reproducibility coefficient for this method, and significant correlation between US-TDI and VF/HRM parameters. US-TDI showed mean time to open CE wall and mean velocity of CE wall opening significantly differed between patients and healthy controls ( P < 0.01). In conclusion, we have developed a US-TDI method for easily assessing CE WM in daily practice and also found significant differences in CE WM between mild OD patients and healthy controls. NEW & NOTEWORTHY A new ultrasonographic screening method using tissue Doppler imaging for oropharyngeal dysphagia was found to be a reliable, reproducible, and well-tolerated method. There is a significant correlation between this new method and conventional methods. This method revealed that patients having mild symptoms of oropharyngeal dysphagia had already significantly delayed cervical esophageal wall opening.

Análise quantitativa das curvas de língua na avaliação ultrassonográfica da fala para o som [j] em adultos e crianças

RESUMO Objetivo Analisar e comparar os contornos médios de língua e os gestos articulatórios na produção do [j] em adultos e crianças com desenvolvimento típico e crianças com desenvolvimento atípico de fala. As crianças com desenvolvimento atípico de fala apresentavam desordens nos sons da fala caracterizadas como desvio fonológico. Método O diagnóstico foi determinado pelas avaliações fonoaudiológicas. Desse modo, a amostra foi constituída por três grupos: 30 adultos com desenvolvimento típico de fala (idades entre 19 e 44 anos), 30 crianças com desenvolvimento típico de fala e 30 crianças com desvio fonológico, denominadas neste estudo como atípicas (idades entre quatro anos e oito anos e onze meses). Para todos os grupos, foi realizada avaliação ultrassonográfica dos movimentos da língua. A pesquisa comparou os contornos médios de língua entre os três grupos em diferentes contextos vocálicos seguintes ao som [j]. Para a delimitação dos gestos, considerou-se a elevação máxima da ponta da língua, utilizando-se software Articulate Assistant Advanced (AAA) e imagens no plano sagital/Modo B. Os pontos que interceptaram as curvas de língua foram analisados pela ferramenta estatística R. Os gráficos dos contornos de língua foram obtidos através do cálculo de intervalo com 95% de confiança. Depois dessa etapa, foram obtidas as regiões com diferenças significativas (p-valor ≤ 0,05) entre os grupos de CT e CA. Resultados Os contornos médios de língua demonstraram o gesto para a semivogal [j] na comparação entre crianças típicas e atípicas. Para a semivogal [j], há um gesto de língua, de dorso, em direção à área central do palato duro, sendo observadas diferenças significativas entre as crianças. Conclusão Os resultados permitiram concluir que existem diferenças entre os grupos de crianças quanto à capacidade de refinar os gestos articulatórios.

Expanding Instrumental Options for Dysphagia Diagnosis and Research: Ultrasound and Manometry

Diagnostic assessment of swallowing in routine clinical practice relies heavily on the long-standing techniques of videofluoroscopic swallowing study (VFSS) and videoendoscopic evaluation of swallowing (VEES). These complementary and sophisticated techniques provide a real-time visualization of biomechanical movements of the structures involved in swallowing and consequent effects on bolus flow. Despite the sophistication of this instrumentation, interpretation relies heavily on subjective clinical judgement and temporal resolution is limited, limitations that may influence patient management. Adjunctive diagnostic assessments may be utilized to compensate for the limitations posed by VFSS and VEES. Ultrasound and pharyngeal manometry do not represent the latest in technological advances, with both emerging in swallowing research over 20 years ago. However, both have resisted integration into routine clinical practice, despite the fact that they offer quantitative metrics of swallowing that are not available using standard techniques. The aim of this review is to present recent research on these two less frequently used modalities in clinical swallowing assessment, discuss potential applications in clinical practice and review supportive data on test-retest reliability, rater reliability and validity. The paper will conclude with a case report that exemplifies the unique contribution of these modalities in executing and revising therapeutic approaches for a patient with neurogenic dysphagia.

The progression of thyroid cartilage calcification as it relates to the utilization of laryngeal ultrasound

OBJECTIVES/HYPOTHESIS

The purpose of this study is to review the computed tomography (CT) scans of infants, children, and adults to assess the degree of calcification of the thyroid cartilage at various ages in order to understand in which age group laryngeal ultrasound can be utilized.

STUDY DESIGN

Retrospective.

METHODS

Two hundred patients from newborn to 50 years who received a CT scan of the neck were identified. The Hounsfield units (HU) of the thyroid cartilage were calculated at one o'clock, four o'clock, eight o'clock, and eleven o'clock at the level of the true and false vocal fold. The Spearman correlation coefficient was calculated to evaluate the correlation between each measure and age, then a linear regression with a logarithmic transformation was applied to further study how the measures were related to age.

RESULTS

The Spearman correlation coefficients ranged from 0.58 to 0.75. The P values of these coefficients were all < 0.0001, showing a significant relationship to age. The age increase by 1 year resulted in increased calcification by 1.5% to 4%. The Wilcoxon signed rank test compared the rate of calcification at each site measured. This showed that the two posterolateral sites calcify faster than the two anteromedial sites.

CONCLUSION

The thyroid cartilage calcifies at a rate that is significantly related to increasing age and calcifies in a posterolateral to anteromedial direction. Based on the HU, the thyroid cartilage is not consistently denser than soft tissue until greater than 40 years of age, which would make laryngeal ultrasound feasible for this population.

LEVEL OF EVIDENCE

4.

Application of B+M-Mode Ultrasonography in Assessing Deglutitive Tongue Movements in Healthy Adults

Background

The purpose of this study was to evaluate tongue movements during swallowing in healthy adults using the B+M-mode ultrasonography, and to determine a common feature in the M-mode traces for quantitative measurement and individual comparison of tongue movements.

Material/Methods

Ninety healthy subjects were divided into 3 groups according to age (20–39, 40–59, and 60–80 years). The tongue movements during 3 saliva swallows were examined using real-time B+M-mode ultrasonography. The M-mode traces of tongue movements were recorded and evaluated.

Results

Both intra-individual and inter-individual differences were detected in the M-mode traces during the 3 saliva swallows. Characteristic types were seen during the individual swallowing phases of M-mode traces: 2 activity types in phase I, 2 types in phase IIb, and 3 types in phase III. However, no variations were seen during phase IIa, in which all subjects displayed a continuous upsloping trace. The average range of swallow-related tongue radial displacement during phase IIa decreased gradually with age, while the average duration of tongue movement during phase IIa increased gradually with age. These 2 trends were not statistically significant across age groups. However, differences between sexes were found in both the range of tongue radial displacement and the duration of deglutitive lingual actions during phase IIa in all 3 age groups (P<0.05).

Conclusions

B+M-mode ultrasonography may offer a quick and safe alternative for the preliminary evaluation of deglutitive tongue movements.

Ultrasound Imaging for Analyzing Lateral Tongue Movements during Mastication in Adults with Cerebral Palsy Compared with Adults without Oral Motor Disabilities

Described here is an ultrasound technique used to study tongue movements, particularly lateral tongue movements, during mastication. A method to analyze spatial and temporal tongue movements was developed, and the feasibility of using this method was evaluated. Biplane ultrasound images of tongue movements of four adults without oral motor disability and two adults with oral motor disability as a result of cerebral palsy, were acquired. Tongue movements were analyzed in the coronal and sagittal planes using B-mode and M-mode ultrasonography. Inter-rater and intra-rater agreement for manual tracing of tongue contours was good (ICC = 0.81 and 0.84, respectively). There were significant differences between the two adult groups in movement frequency in the horizontal direction in both coronal and sagittal planes. In the coronal plane, differences in movement frequency and range of vertical movement were detected. Data obtained from sagittal images, with the exception of vertical frequency, indicated no differences between the groups. The protocol developed in this study (using B-mode and M-mode) proved to be valid and reliable. By using this protocol with individuals with and without oral motor disability, we were able to illustrate the clinical application of our protocol to evaluation of differences in tongue movements during mastication.

Reliability of ultrasound evaluation of hyoid-larynx approximation with positional change

We evaluated the reliability of ultrasound evaluation of hyoid-larynx approximation with positional change. Twenty healthy volunteers (10 men, 10 women) participated in this study. The distance between the hyoid bone and thyroid cartilage was measured by ultrasound in both the sitting and supine positions. Hyoid-larynx approximation was defined as the shortest distance between the lower tip of the hyoid bone and the upper end of the thyroid cartilage during swallowing. The transducer was placed in a longitudinal position above the midline of the larynx, which allowed visualization of the hyoid bone and thyroid cartilage. Patients were given 5 mL of water and swallowed. The measurement was repeated three times to enable averaging in each position. Using the mean distance at rest and the shortest distance during swallowing, we calculated relative laryngeal elevation. There was no significant difference in resting distance between the hyoid bone and thyroid cartilage with positional change or gender, with identical relative laryngeal elevation. However, there was a negative correlation between the resting and approximation distance and body mass index. In conclusion, ultrasound evaluation in healthy volunteers revealed no difference in hyoid-laryngeal approximation on swallowing in either the supine or sitting position. This finding is likely to be of value in the investigation of dysphagia.

Motor functions in trumpet playing-a real-time MRI analysis

INTRODUCTION

The function of the orofacial and pharyngeal musculature for sound generation in brass instruments is insufficiently investigated. The contribution of muscles defying direct observation remains poorly understood. Time-resolved magnetic resonance imaging (MRI) allows visualization of muscle function as well as changes of the oropharyngeal cavities during muscle activation.

METHODS

We used fast 3-T MRI imaging to analyze motor activation during sound generation in brass instruments. Twelve professional trumpeters were analyzed at different pitch, loudness and dynamic. MR images were analyzed for position of the mouthpiece to lips and teeth, pivoting, nasopharyngeal closure and changes in the area of oral and pharyngeal cavity.

RESULTS

Of the 12 subjects, eight positioned the mouthpiece mainly to the upper lip, three in equal parts to upper and lower lip, and only one mostly to the lower lip. The last turned out to be the only subject with upward pivoting. All subjects had a complete velopharyngeal closure. Measurements of the oral and pharyngeal cavities showed an increase when subjects were playing higher pitches. The increase in areas of oral and pharyngeal cavity was present also when switching from lower to higher loudness and when performing crescendo to decrescendo. Enlargement of the oral and pharyngeal cavity was less pronounced with increasing loudness. But no general difference in change of oral and pharyngeal cavity could be observed.

CONCLUSIONS

The present study shows that it is possible to measure motor function and its implications on oral as well as pharyngeal cavities during sound generation in brass instruments. These changes seem to follow a reproducible pattern.

Lateral pharyngeal wall motion analysis using ultrasonography in stroke patients with dysphagia

We aimed to analyze lateral pharyngeal wall (LPW) motion using ultrasonography. The subjects were stroke patients with dysphagia (n = 26) and normal controls (n = 15). The stroke patients were divided into two groups based on a videofluoroscopic swallowing study (VFSS). Group A (n = 12) had a penetration or aspiration in VFSS findings, while group B (n = 14) had no evidence of a penetration or aspiration. We assessed LPW motion using B/M-mode ultrasonography. We performed the comparative analysis among each group and the relationship between LPW motion parameters and the VFSS parameters of the pharyngeal phase. The mean LPW displacement of group A, B was significantly decreased than that of normal controls. The mean LPW duration of group A, B was increased than that of normal controls, but not statistically significant. The mean LPW displacement of group A was significantly correlated with the residue in valleculae, pharyngeal delay time and laryngeal elevation, but that of group B was not significantly correlated. The mean LPW duration of group A, B was not significantly correlated with the VFSS parameters of the pharyngeal phase. We suggest that LPW motion analysis could be a useful alternative method for the evaluation of the pharyngeal phase in stroke patients with a penetration or aspiration in VFSS findings.

Application of ultrasonography in assessing oropharyngeal dysphagia in stroke patients

This study applied submental ultrasonography (SUS) to measure changes in dysphagic stroke patients' tongue thickness and hyoid bone displacement when swallowing 5 mL of water and correlated the results with the severity of clinical dysphagia. We included 60 stroke patients (30 tube-feeding-dependent and 30 on regular oral intake) and 30 healthy controls. An additional 10 healthy people were recruited to assess the reliability of SUS. Measurements of hyoid bone displacement using videofluoroscopic swallowing study (VFSS) and SUS were compared for 12 stroke patients to assess the correlation between the two methods. Changes in tongue thickness and hyoid bone displacement were significantly less in the tube-feeding group. Those with a tongue thickness change of less than 1.0 cm and hyoid bone displacement of less than 1.5 cm were likely to be tube-feeding. SUS showed good intra-rater/inter-rater reliability and correlated well with VFSS measurement. SUS can be an adjunct assessment tool of swallowing.

Intra- and inter-rater reliability for analysis of hyoid displacement measured with sonography

PURPOSE

Anterior hyoid displacement is essential for efficient swallowing and is usually investigated with videofluoroscopy. Ultrasound offers a less expensive and noninvasive method of investigation. The present study investigated the viability of a novel method of quantifying hyoid displacement from sonograms using an anatomic reference point, through an evaluation of inter- and intra-rater reliability.

METHODS

Three raters reviewed the sonographic video sweeps of five discrete swallows from each of five participants for inter-rater reliability. The primary investigator measured each swallow on two occasions for intra-rater reliability. Electronic calipers were used to measure distances from a "rest" frame prior to the swallow of interest and a "maximal displacement" frame, at which the hyoid bone was at maximal anterior displacement during each swallow.

RESULTS

Single-measure intraclass correlation coefficient was high for inter-rater agreement at 0.86 for rest measures and 0.86 for maximal displacement. Intra-rater reliability was even higher at 0.95 for rest and 0.98 for maximal displacement.

CONCLUSIONS

These preliminary results suggest that by using a novel analysis approach involving an anatomic reference point, raters can achieve high agreement on measurement of position of hyoid at maximal displacement relative to rest.

Tongue-pressure and hyoid movement timing in healthy liquid swallowing

It was hypothesized that tongue-palate pressure generation might directly facilitate hyoid movement in swallowing through the anatomical connections of the extrinsic tongue muscles. If true, non-invasive measures of tongue-palate pressure timing might serve as a proxy measure of hyoid excursion. The timing relationships between events in the tongue-palate pressure and hyoid movement profiles during water and nectar-thick liquid swallowing in healthy adults were explored. Concurrent intra-oral manometry and submental B-mode midsagittal ultrasound were recorded. It was determined that there is no obligate sequence in the onsets, or offsets, of tongue-palate pressures and hyoid excursion. Timing lags (either of hyoid movement lagging tongue-palate pressures or vice versa) fell within 0.5 s, on average. It is concluded that tongue-palate pressure generation and hyoid movement are separate phenomena in the swallowing sequence and that non-invasive measures of tongue-pressure timing cannot be used reliably as proxy measures of hyoid movement timing.

Ultrasonographic evaluation of geniohyoid muscle movement during swallowing: a study on healthy adults of various ages

Our purpose in this study was to investigate the application of B+M-mode ultrasound (B/M-mode) imaging as a new approach to quantifying activity patterns of the geniohyoid muscles during swallowing and to assess how these patterns differ according to age and gender. Sixty healthy volunteers (30 men, 30 women) were divided into three age groups (20-39, 40-59, 60-79 years). The subjects were then given 10 ml of mineral water. Ultrasonographic imaging was repeated 5 times and measurements were averaged. Simultaneous B/M-mode images were captured at two regions along the lateral geniohyoid muscle wall. All geniohyoid muscle movement was recorded by real-time B/M-mode. In all cases, ultrasonographic images of the geniohyoid muscle movement during swallowing were easily visualized with the use of real-time B/M-mode. The average moving distance and the duration of movement of the geniohyoid muscle during contraction increased gradually with age. There was a significant difference in ultrasonic measurements of the moving distance and the duration of movement during swallowing between males and females in the three age groups (P < 0.05). B/M-mode imaging provides a simple, noninvasive technique for visual assessment of the lateral geniohyoid muscle wall and may provide a clinical method for evaluating swallowing.

Tongue position after deglutition in subjects with habitual open-mouth posture under different functional conditions

OBJECTIVE

To test the null hypothesis of no significant differences in (1) the duration of the post-deglutory, cranial tongue rest position (CTP) between different functional orofacial conditions and (2) the presence or absence of an oral screen (OS) in subjects with a habitual open-mouth posture.

SUBJECTS

Twenty-nine subjects (aged 6-16; mean: 9.69 years; 13/16 girls/boys) were selected according to the inclusion criterion of a habitual, daytime open-mouth posture.

METHODS

Deglutition was screened at baseline during resting respiration using orofacial polysensography and simultaneous assessment of tongue-to-palate position and nasal airstream, during five functional intervals of 8 min each: F1 without instruction (RR); F2 the same, but including an oral screen (RROS); F3 with OS and the instruction to maintain a tongue-to-palate contact (IROS); F4 with OS and the instruction to perform tongue repositioning manoeuvres at the time of spontaneous swallowing (TRMOS); and F5 corresponds to F3 omitting OS (IR). Duration and frequency of deglutition were analysed descriptively as well as by anova and subsequent multiple comparisons, and the CTP was evaluated with chi-square tests and paired comparisons at a significance level of 5%.

RESULTS

Of 542 identified swallowing acts, 75% were accompanied by a post-deglutory CTP. Mean duration of CTP increased for functional conditions RR/1.01s > RROS/2.56s > IR/3.21s > IROS/6.53s > TRMOS/6.58s. The null hypothesis (1) was rejected in comparison of resting respiration (F1, F2) with IROS and TRMOS, whereas the use of an oral screen alone did not significantly prolong the duration of CTP.

Non-invasive assessment of benign vocal folds lesions in children by means of ultrasonography

OBJECTIVES

Flexible fiberoptic endoscopes have made pediatric laryngeal examinations an everyday practice, even though fiberoptic-flexible laryngoscopy (FFL) is not always well tolerated in young children because of limited cooperation. Laryngeal ultrasonography (LUS) has been applied to normal and pathological findings in infants and children, allowing the assessment of subglottic hemangiomas, laryngeal stenosis and paralysis. No previous study assessed benign vocal folds lesions by LUS in children. The aim of this study is to evaluate the possibility of LUS to detect benign vocal fold lesions in children by comparing the results of FFL in 16 children with those of LUS.

METHODS

Sixteen children (9 males and 7 females) with a mean age of 7.5+/-4.0 years were included in the study. Each child underwent FFL performed by a skilled phoniatrician and LUS performed blindly by an expert radiologist.

RESULTS

On FFL bilateral vocal folds nodules were found in 9 patients, vocal fold cyst in 2 other patients, while in 2 children the vocal folds appeared normal. Laryngeal papyllomatosis, vocal fold polyp and vocal fold irregularity were found in only one patient. LUS enabled the diagnosis in all the 14 patients with vocal fold lesions. Bilateral hyperechoic lesions were visible in 10 patients, while hypoechoic lesions were found in three patients. No lesion were found in two children, while one patient presented with a monolateral hyperechoic lesion.

CONCLUSIONS

LUS was accurate, safe, well accepted and tolerated. LUS appears to be a useful diagnostic tool for supplementing FFL in the assessment of benign vocal fold lesions in children and may represent an interesting alternative in everyday clinical practice.

Ultrasonographic evaluation of hyoid-larynx approximation in dysphagic stroke patients

Hyoid-larynx approximation is an essential part of the swallowing process, and is related to airway protection. We aimed to evaluate the reliability of ultrasonographic examination of hyoid-larynx approximation and measure the approximation in stroke patients with or without dysphagia. Fifteen normal subjects and 40 stroke patients with or without dysphagia admitted to the Department of Rehabilitation Medicine of a tertiary hospital between July 2006 and February 2007 participated in this study. The distance between the thyroid cartilage and hyoid bone during swallowing was measured by ultrasound. Hyoid-larynx approximation was defined as the distance obtained by subtracting the shortest distance between the hyoid bone and thyroid cartilage during swallowing from the initial resting distance. Ten stroke patients with dysphagia also underwent standard videofluoroscopic swallowing study (VFSS). The change percentage of hyoid-larynx approximation was very similar between ultrasonographic examination and VFSS. There was no significant difference in resting distances between the thyroid cartilage and hyoid bone between normal subjects and stroke patients with or without dysphagia. Among stroke patients, hyoid-larynx approximation was less in the dysphagia group than in the nondysphagia group. In conclusion, ultrasound can quantitatively measure hyoid-larynx approximation with good reliability. Hyoid-larynx approximation was significantly reduced in stroke patients with dysphagia.

Biomecânica ultra-sonográfica da deglutição: estudo preliminar

OBJETIVO: Verificar, por meio da ultra-sonografia, os parâmetros espaciais do complexo hiolaríngeo na dinâmica da deglutição e a associação entre idade e efeitos. MATERIAIS E MÉTODOS: Neste estudo quantitativo e prospectivo foram incluídos 39 indivíduos sadios, de ambos os gêneros, na faixa etária de 20 a 70 anos (média, 45,56; desvio-padrão, 14,53). Avaliou-se a biomecânica da deglutição correspondente à medida da distância entre a porção superior do osso hióide e a borda superior da cartilagem tireóide, no momento de máxima elevação laríngea. As medidas foram realizadas com a ingestão de alimentos de consistências líquida e pastosa. RESULTADOS: A variação da distância da laringe ao hióide apresentou associação positiva com a idade, somente na deglutição de alimento pastoso, consistência na qual é solicitada maior atividade de propulsão lingual do que nos líquidos. CONCLUSÃO: É possível que o aumento da distância entre o hióide e a laringe, que representa menor elevação laríngea, na deglutição de pastosos, ocorra por efeito do envelhecimento, processo no qual se verifica diminuição de reservas funcionais, mesmo em indivíduos sadios. A ultra-sonografia pode detectar comportamentos relacionados a consistências alimentares, o que mostra sua possível potencialidade diagnóstica na avaliação da deglutição.

Mechanical basis for lingual deformation during the propulsive phase of swallowing as determined by phase-contrast magnetic resonance imaging

The tongue is an intricately configured muscular organ that undergoes a series of rapid shape changes intended to first configure and then transport the bolus from the oral cavity to the pharynx during swallowing. To assess the complex array of mechanical events occurring during the propulsive phase of swallowing, we employed tongue pressure-gated phase-contrast MRI to represent the tissue's local strain rate vectors. Validation of the capacity of phase-contrast MRI to represent local compressive and expansive strain rate was obtained by assessing deformation patterns induced by a synchronized mechanical plunger apparatus in a gelatinous material phantom. Physiological strain rate data were acquired in the sagittal and coronal orientations at 0, 200, 400, and 600 ms relative to the gating pulse during 2.5-ml water bolus swallows. This method demonstrated that the propulsive phase of swallowing is associated with a precisely organized series of compressive and expansive strain rate events. At the initiation of propulsion, bolus position resulted from obliquely aligned compressive and expansive strain, vertically aligned compressive strain and orthogonal expansion, and compressive strain aligned obliquely to the styloid process. Bolus reconfiguration and translocation resulted from a combination of compressive strain occurring in the middle and posterior tongue aligned obliquely between the anterior-inferior and the posterior-superior regions with commensurate orthogonal expansion, along with bidirectional contraction in the distribution of the transversus and verticalis muscle fibers. These data support the concept that propulsive lingual deformation is due to complex muscular interactions involving both extrinsic and intrinsic muscles.

A guide to analysing tongue motion from ultrasound images

This paper is meant to be an introduction to and general reference for ultrasound imaging for new and moderately experienced users of the instrument. The paper consists of eight sections. The first explains how ultrasound works, including beam properties, scan types and machine features. The second section discusses image quality, including the interpretation of anatomical features and artefacts seen in the image. The third section discusses the validity of the data collection procedures, including the effects of stabilizing the transducer and head position, and discusses some methods for stabilization. Section four discusses validation of the ultrasound and stabilization systems. The fifth section presents a sample recording set-up, supplemental information, and normalization strategies for sessions and subjects. In section six are methods of extracting contours from ultrasound images, displaying them, and analysing them. The seventh section considers the tracking of pellets on the tongue surface and the differences between tracking tissue points and continuous surfaces. The last section presents methods, challenges and results of 3D, computerized reconstruction of tongue surfaces. An outline of the paper can be found in Appendix I.