High-resolution manometry of pharyngeal swallow pressure events associated with head turn and chin tuck

Dendritic alterations precede age-related dysphagia and nucleus ambiguus motor neuron death

Motor neurons (MNs) within the nucleus ambiguus innervate the skeletal muscles of the larynx, pharynx and oesophagus, which are essential for swallow. Disordered swallow (dysphagia) is a serious problem in elderly humans, increasing the risk of aspiration, a key contributor to mortality. Despite this importance, very little is known about the pathophysiology of ageing dysphagia and the relative importance of frank muscle weakness compared to timing/activation abnormalities. In elderly humans and in aged Fisher 344 (F344) rats, a variety of motor pools exhibit weakness and atrophy (sarcopenia), contemporaneous to MN death. Synchronisation of swallow is dependent on the stability of MN dendrites, which integrate neural circuits. Dendritic derangement occurs in many neuromotor degenerative conditions prior to MN death. We hypothesise behavioural weakness and death of nucleus ambiguus MNs will occur by age 24 months in F344 rats and that this will be preceded by swallow-respiration dyscoordination and dendritic arbour degenerations from 18 months compared to controls at 6 months. Using pressure catheters to estimate laryngeal and diaphragm function during naturalistic water bolus applications, we show that swallow number and post-swallow apnoeas are altered from 18 months. Swallow pressure (weakness) and nucleus ambiguus MN numbers (evaluated via stereological assessments of Nissl staining) were reduced at 24 months. Dendritic lengths, surface areas and dendritic spines were reduced in nucleus ambiguus MNs from 18 months (evaluated by confocal imaging of Golgi-Cox impregnated brainstem). These results show that synapse loss occurs prior to MN death and behavioural weakness. Strategies to preserve synapses may be of utility in ameliorating sarcopenia. KEY POINTS: Dysphagia is a major contributor to ageing morbidity and mortality, but the underling pathophysiology is unexplored. Here, in Fischer 344 rats, we use pressure and timing evaluations of swallow-respiration, showing timing impairments occur prior to frank pressure defects. In nucleus ambiguus motor neurons, dendritic defects were apparent with the onset of swallow-respiration dyscoordination, with frank motor neuron loss occurring subsequently to synapse loss. Our results show that synapse loss occurs prior to motor neuron death and behavioural impairments. Strategies to preserve synapses may be of utility in ameliorating sarcopaenia.

Effects of Capsaicin on Masticatory and Swallowing Function

INTRODUCTION

Recent studies have shown that capsaicin improves the pharyngeal swallowing reflex. However, the mechanism by which capsaicin alters mastication and oesophageal function remains unclear. This study aimed to investigate the effects of capsaicin on masticatory and oesophageal function.

MATERIALS AND METHODS

Participants were 12 healthy individuals (7 men, 5 women: aged 31.5 ± 3.0 years). The participants ingested five rice cakes without capsaicin and then five rice cakes containing capsaicin. Total mastication frequency, total mastication time, and mastication rate were measured. Pharyngeal and upper oesophageal sphincter (UES) parameters were evaluated using high-resolution manometry (HRM). The masticatory and HRM parameters were compared between the ingestion of capsaicin-containing and non-capsaicin containing rice cakes.

RESULTS

The total mastication frequency and total mastication time(s) for capsaicin ingestion were significantly smaller (20.3 ± 9.4 vs. 22.4 ± 7.4; p = 0.011) and shorter (14.2 ± 7.0 vs. 15.4 ± 5.6; p = 0.038), respectively, than those for non-capsaicin ingestion. Comparison of the HRM parameters revealed significantly higher hypopharyngeal contractile integral (mmHg-s-cm) (56.6 ± 40.7 vs. 49.7 ± 43.6; p = 0.016) and proximal oesophageal contractile integral (mmHg-s-cm) (492.3 ± 292.64 vs. 381.2 ± 266; p < 0.001), significantly shorter UES basal pressure (mmHg) (93.6 ± 37.8 vs. 114.5 ± 43.4; p < 0.001), and significantly longer UES relaxation time (ms) (486.7 ± 90.7 vs. 431.2 ± 82.3; p < 0.001) for capsaicin ingestion than for non-capsaicin ingestion.

CONCLUSIONS

Decreased mastication frequency and time, increased hypopharyngeal and proximal oesophageal contractile integral, and prolonged UES opening time with capsaicin ingestion suggests that capsaicin improves oral, pharyngeal and oesophageal phases of swallowing.

Compensatory Swallowing Strategies Recommended in Oncology Practice: Practice Patterns and Relationship to Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) Grades

Compensatory swallow strategies are recommended to improve swallow safety and efficiency; however, there is limited evidence on use in specific populations or their relationship to swallow study results. We sought to describe/explore strategy recommendations in an oncology practice and their relationship to Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) grades as a marker of clinical utility of the tool. This is a sub-study of a STARI-guided retrospective implementation evaluation at a single comprehensive cancer center. Electronic health record databases were queried to sample all modified barium swallow studies (MBS) for all adult oncology patients from 2016 to 2021, excluding total laryngectomy, leak studies and those with missing DIGEST grades. For patients with multiple MBS studies across the study period, one MBS was randomly selected to be included in the analytic sample. DIGEST grade, diet recommendation, oncologic details, and swallow strategy details were chart abstracted. Strategies and oral intake recommendations were classified from least to most restrictive. This study included 4570 patients representing diverse oncology populations (46% head and neck). DIGEST grades indicating at least mild dysphagia (grades ≥ 1) were reported in 2486 of MBS (54%). Strategies were recommended in 2028 MBS (44%). As DIGEST grade increased so did strategy utilization and complexity (Spearman's r (rS) = 0.76, p < 0.0001). This pattern was consistent for Safety (rS = 0.68) and Efficiency (rS = 0.73) grades (both p < 0.0001). Swallow strategies are frequently recommended in oncology populations. This is the first study to show a systematic link between DIGEST grade and MBS compensatory strategy recommendations, supporting clinical effectiveness of DIGEST as an evidence-based practice tool.

Physiology and Execution of Swallowing Maneuvers in 3D Videos: Integrating the Technology into Patient Care

Educational technologies have proven to be an effective way to guide and educate patients, allowing them to increase awareness of their dysphagia condition and how treatment will help them. In this sense, this study aimed to develop and validate the content and appearance of 3D iconographic videos, which addressed the physiological demonstration and execution of protective and facilitating swallowing maneuvers, as well as verifying the feasibility of its use in teleconsultation, having adults and elderly people with oropharyngeal dysphagia as the main target audience. The development of the 3D videos was elaborated based on a guiding scientific script, constructed from an integrative literature review. After the development of the 3D videos by the digital designer, a committee of 12 expert judges evaluated the material produced to validate the content and appearance where a minimum agreement index of 0.8 among the judges was considered satisfactory. Subsequently with the validated material, the proof of concept was conducted together with the target population of 10 dysphagic patients through individual teleconsultation via Google Meet platform. After the teleconsultation, patients responded to a Google Forms questionnaire, analyzing the videos presented. From the integrative literature review, 29 studies that contained relevant information about the physiological effects caused by swallowing maneuvers were selected. Based on this information, the scientific script was created, allowing a detailed description of the physiological events that occurred during swallowing while executing the maneuvers. With the finished script, 3D videos of swallowing maneuvers were produced. After developing the material, the committee of expert judges validated the content and appearance. The twelve items that had an agreement index below 0.8 were adjusted. Once the adjustments were completed, the videos were analyzed again, obtaining approval from the judges, and ensuring the validation of content and appearance of the material developed. A proof of concept was conducted on ten dysphagic patients. The maneuver applied was chosen according to the patient's physiological changes, causing only 4 of the 9 maneuvers to be tested, as the patients did not demonstrate changes in swallowing that would justify the use of the other maneuvers. After this, patients answered a form in which all items covered received positive evaluations, related to both ease of understanding and learning. This study allowed the development of the 3D videos with a didactic demonstration of the physiology and execution of protective and facilitating swallowing maneuvers, in addition to having its content and appearance validity assured through analysis by the committee of expert judges.

Efficacy and Safety of "Vacuum Swallowing" Based on a Strong Negative Esophageal Pressure in Healthy Individuals

Vacuum swallowing is a unique method for improving the pharyngeal passage of a bolus by creating subatmospheric negative pressure in the esophagus. However, whether healthy individuals and other patients with dysphagia can reproduce vacuum swallowing remains unclear. Therefore, this study aimed to assess whether healthy individuals verified using high-resolution manometry (HRM) could reproduce vacuum swallowing and evaluate its safety using a swallowing and breathing monitoring system (SBMS). Two healthy individuals who mastered vacuum swallowing taught this method to 12 healthy individuals, who performed normal and vacuum swallowing with 5 mL of water five times each. The minimum esophageal pressure and the maximum pressure of the lower esophageal sphincter (LES) were evaluated during each swallow using the HRM. Additionally, respiratory-swallowing coordination was evaluated using the SBMS. Ten individuals reproduced vacuum swallowing, and a total of 50 vacuum swallows were analyzed. The minimum esophageal pressure (-15.0 ± 4.9 vs. -46.6 ± 16.7 mmHg; P < 0.001) was significantly lower, and the maximum pressure of the LES (25.4 ± 37.7 vs. 159.5 ± 83.6 mmHg; P < 0.001) was significantly higher during vacuum swallowing. The frequencies of the I-SW and SW-I patterns in vacuum swallowing were 38.9% and 0%, respectively, using the SBMS. Vacuum swallowing could be reproduced safely in healthy participants with instruction. Therefore, instructing exhalation before and after vacuum swallowing is recommended to prevent aspiration.

Normative High-Resolution Pharyngeal Manometry: Impact of Age, Size of System, and Sex on Primary Metrics and Pressure Stability

There have been many reports of normative pharyngeal swallowing pressures using high-resolution pharyngeal manometry, but there is a fair amount of between-subject variance in reported pressure parameters. The purpose of this study was to put forward normative pharyngeal high-resolution manometry measures across the lifespan and investigate the effects of age, size of system, and sex. High-resolution pharyngeal manometry was performed on 98 healthy adults (43 males) between the ages 21 and 89. Pressure duration, maxima, integral, and within-individual variability metrics were averaged over 10 swallows of 10-ml thin liquid. Multiple linear and logistic regressions with model fitting were used to examine how pharyngeal pressures relate to age, pharyngeal size, and sex. Age was associated with tongue base maximum pressure, tongue base maximum variability, and upper esophageal sphincter-integrated relaxation pressure (F3,92 = 6.69; p < 0.001; adjusted R2 = 0.15). Pharyngeal area during bolus hold was associated with velopharynx integral (F1,89 = 5.362; p = 0.02; adjusted R2 = 0.05), and there was no significant model relating pharyngeal pressures to C2-C4 length (p < 0.05). Sex differences were best described by tongue base integral and hypopharynx maximum variability (χ2 = 10.27; p = 0.006; pseudo R2 = 0.14). Normative data reveal the distribution of swallow pressure metrics which need to be accounted for when addressing dysphagia patients, the importance of pressure interactions in normal swallow, and address the relative stability of swallow metrics with normal aging.

Residual effect of sequential 4-channel neuromuscular electrical stimulation evaluated by high-resolution manometry

BACKGROUND

High-resolution manometry (HRM) can quantify swallowing pathophysiology to evaluate the status of the pharynx. Sequential 4-channel neuromuscular electrical stimulation (NMES) was recently developed based on the normal contractile sequences of swallowing-related muscles. This study aimed to examine the effects of sequential 4-channel NMES for compensatory application during swallowing and to observe the residual effects after the application of NMES using HRM.

RESULTS

Sequential 4-channel NMES significantly improved the HRM parameters, with respect to the maximal pressure and area of the velopharynx (VP), maximal pressure and area of the mesopharynx (MP), and upper esophageal sphincter (UES) activation and nadir duration. Furthermore, the improvement in the pressure and area variables of the VP and MP showed a tendency to maintain even when measured after NMES, but there are no significant differences.

CONCLUSIONS

The present study suggests that the sequential 4-channel NMES application of the suprahyoid and infrahyoid muscles during swallowing improves the pressure, area, and time variables of the oropharynx, as measured by HRM, and it is likely that the effects may persist even after stimulation. Trial Registration Clinicaltrials.gov, registration number: NCT02718963 (initial release: 03/20/2016, actual study completion date: 06/24/2016, last release: 10/20/2020).

Comprehensive assessment and treatment strategies for dysphagia in the elderly population: Current status and prospects

As the population ages, the prevalence of dysphagia among older adults is a growing concern. Age-related declines in physiological function, coupled with neurological disorders and structural changes in the pharynx associated with aging, can result in weakened tongue propulsion, a prolonged reaction time of the submental muscles, delayed closure of the laryngeal vestibule, and delayed opening of the upper esophageal sphincter (UES), increasing the risk of dysphagia. Dysphagia impacts the physical health of the elderly, leading to serious complications such as dehydration, aspiration pneumonia, malnutrition, and even life-threatening conditions, and it also detrimentally affects their psychological and social well-being. There is a significant correlation between frailty, sarcopenia, and dysphagia in the elderly population. Therefore, older adults should be screened for dysphagia to identify both frailty and sarcopenia. A reasonable diagnostic approach for dysphagia involves screening, clinical assessment, and instrumental diagnosis. In terms of treatment, multidisciplinary collaboration, rehabilitation training, and the utilization of new technologies are essential. Future research will continue to concentrate on these areas to enhance the diagnosis and treatment of dysphagia, with the ultimate aim of enhancing the quality of life of the elderly population.

The Manometric Representation of the Upper Esophageal Sphincter During the Resting State: A Descriptive Study

The upper esophageal sphincter (UES) is the high-pressure zone marking the transition between the hypopharynx and esophagus. There is limited research surrounding the resting UES using pharyngeal high-resolution manometry (HRM) and existing normative data varies widely. This study describes the manometric representation of the resting UES using a clinically accessible method of measurement. Data were obtained from 87 subjects in a normative database of pharyngeal HRM with simultaneous videofluoroscopy. The resting UES manometric region was identified and ten measurement segments of this region were taken throughout the duration of the study using the Smart Mouse function within the manometry software. Intraclass correlation coefficients (ICC) were used to analyze within-subject reliability across measurements. Linear mixed-effects regression models were used to analyze how subject characteristics and manometric conditions influence resting UES pressure. There was excellent within-subject reliability between resting UES mean pressures (ICC = 0.96). In bivariate analysis, there were significant effects of age, number of sensors contained within the resting UES, and preceding swallow volume on mean resting UES pressure. For every 1 unit increase in age, there was a 0.19 unit decrease in resting UES pressure (p = 0.008). For every 1 unit increase in number of sensors contained within the resting UES, there was a 3.71 unit increase in resting UES pressure (p < 0.001). This study presents normative data for the resting UES, using a comprehensive and clinically accessible protocol that can provide standard comparison for the study of populations with swallowing disorders, particularly UES dysfunction, and provides support for UES-directed interventions.

The effectiveness of chin-down manoeuvre in patients with dysphagia: A systematic review and meta-analysis

AIM

The chin-down posture is a widely used compensatory manoeuvre for patients with dysphagia. The aim of this study was designed to systematically measure the effectiveness of chin-down manoeuvre application.

METHODOLOGY

We retrieved the PubMed, Web of Science, Embase, Cochrane Library, EBSCO, Medline, CNKI, WANFANG, VIP and SinoMed databases from inception to 30 August 2022. Raters independently screened literature according to inclusion and exclusion criteria. The quality of the included literature was evaluated, and data were extracted. The software Review Manager software 5.3 was used for statistical analysis.

RESULTS

Fourteen studies with a total of 571 patients were included in this meta-analysis. The meta-analysis indicated that chin-down manoeuvre could significantly reduce the risk of aspiration (MD = -1.35, 95% CI [-2.25, -0.44], Z = 2.92, p < .01), decrease the chin angle (MD = -12.20, 95% CI [-14.61, -9.79], Z = 9.91, p < .001), shorten oral transit time (MD = -0.81, 95% CI [-1.20, -0.43], Z = 4.17, p < .001), reduce the maximum swallowing pressure at upper oesophageal sphincter (MD = -82.07, 95% CI [-112.77, -51.37], Z = 5.24, p < .001) and decrease pharyngeal residue.

CONCLUSIONS

Existing evidence indicated that chin-down manoeuvre could reduce the risk of aspiration and pharyngeal residue, decrease the maximum swallowing pressure at UES. More large-sample, high-quality clinical trials are still needed in the future to further ascertain the results of this research.

A Systematic Review of Pharyngeal High-Resolution Manometry Normative Data

PURPOSE

The utilization of high-resolution pharyngeal manometry (HRPM) in the evaluation of pharyngeal dysphagia has been increasing; however, standardization of its use has lagged behind. Without standardization using normative values, it is difficult for clinicians to adopt this emerging technology into meaningful use. Our goal is to map and compare the published normative values for common HRPM metrics in order to help establish consensus reference values.

METHOD

A systematic review was conducted on prospective and retrospective studies that included HRPM metrics, defined by an international working group consensus, in healthy adult populations. Data on the following variables were extracted when available: contractile integrals of the pharynx (PhCI), velopharynx, mesopharynx, and hypopharynx, as well as the upper esophageal sphincter (UES) integrated relaxation pressure (IRP), relaxation time (RT), maximum admittance, and hypopharyngeal intrabolus pressure.

RESULTS

Thirty studies were included. Significant variation existed in the technique and equipment used to perform procedures between the different studies. Lower PhCIs and UES IRPs were seen in younger compared to older individuals. Higher UES RTs were found in individuals in the upright position compared to the supine position and in those using larger boluses sizes or smaller catheters.

CONCLUSIONS

Due to the wide variety of protocols, catheter configurations, manufacturers, and software used in the existing literature, it is difficult to formulate consensus on HPRM normative values using pooled data. Prospective studies adhering to standardized HRPM protocols for specific catheter configurations and manufacturers with larger cohorts of normal individuals are necessary to establish proper reference values for HRPM metrics.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24843753.

Differences in velopharyngeal pressures during speech sound production in patients with unilateral cleft lip and palate (UCLP) and healthy individuals

Background

During articulation the velopharynx needs to be opened and closed rapidly and a tight closure is needed. Based on the hypothesis that patients with cleft lip and palate (CLP) produce lower pressures in the velopharynx than healthy individuals, this study compared pressure profiles of the velopharyngeal closure during articulation of different sounds between healthy participants and patients with surgically closed unilateral CLP (UCLP) using high resolution manometry (HRM).

Materials and methods

Ten healthy adult volunteers (group 1: 20-25.5 years) and ten patients with a non-syndromic surgically reconstructed UCLP (group 2: 19.1-26.9 years) were included in this study. Pressure profiles during the articulation of four sounds (/i:/, /s/, /ʃ/ and /n/) were measured by HRM. Maximum, minimum and average pressures, time intervals as well as detection of a previously described 3-phase-model were compared.

Results

Both groups presented with similar pressure curves for each phoneme with regards to the phases described and pressure peaks, but differed in total pressures. An exception was noted for the sound /i:/, where a 3-phase-model could not be seen for most patients with UCLP. Differences in velopharynx pressures of 50% and more were found between the two groups. Maximum and average pressures in the production of the alveolar fricative reached statistical significance.

Conclusions

It can be concluded that velopharyngeal pressures of patients with UCLP are not sufficient to eliminate nasal resonance or turbulence during articulation, especially for more complex sounds. These results support a general understanding of hypernasality during speech implying a (relative) velopharyngeal insufficiency.

The dynamics of deglutition during head rotation using dynamic 320-row area detector computed tomography

Objective

We aimed to elucidate the dynamics of deglutition during head rotation by acquiring 320-row area detector computed tomography (320-ADCT) images and analyzing deglutition during head rotation.

Methods

This study included 11 patients experiencing globus pharyngeus. A 320-ADCT was used to acquire images in two types of viscosity (thin and thick), with the head rotated to the left. We measured the movement time of deglutition-related organs (soft palate, epiglottis, upper esophageal sphincter [UES], and true vocal cords) and pharyngeal volume (bolus ratio at the start of UES opening [Bolus ratio], pharyngeal volume contraction ratio [PVCR], and pharyngeal volume before swallowing [PVBS]). A two-way analysis of variance was performed for statistical analysis, and all items were compared for significant differences in terms of head rotation and viscosity. EZR was used for all statistical analyses (p-value <.05).

Results

Head rotation significantly accelerated the onset of epiglottis inversion and UES opening compared with no head rotation. The duration of epiglottis inversion with the thin viscosity fluid was significantly longer. The bolus ratio increased significantly with thick viscosity. There was no significant difference in viscosity and head rotation in terms of PVCR. PVBS increased significantly with head rotation.

Conclusion

The significantly earlier start of epiglottis inversion and UES opening due to head rotation could be caused by: (1) swallowing center; (2) pharyngeal volume; and (3) pharyngeal contraction force. Thus, we plan to further analyze swallowing with head rotation by combining swallowing CT with manometry and examine its relationship with pharyngeal contraction force.

Level of Evidence

3b.

Economic Evaluation of Clinical, Nutritional and Rehabilitation Interventions on Oropharyngeal Dysphagia after Stroke: A Systematic Review

Background: Post-stroke oropharyngeal dysphagia (PS-OD) and its complications increase healthcare costs, suggesting that its appropriate management is cost-effective. We aimed to assess the efficiency of healthcare interventions in PS-OD management. Methods: A systematic review was conducted following PRISMA recommendations. Four databases were searched from inception through 30 June 2021. Outcome measures were cost-effectiveness and cost-savings of healthcare interventions. English and Spanish literature were included. Narrative and tables were used to present and synthesise evidence. Quality was evaluated using the CHEERS Statement. Results: A total of 244 studies were identified, and 10 were included. Screening and diagnosis of PS-OD studies found: (1) adjusted reduction in hospitalisation costs when assessed during the first admission day; (2) non-significant reduction in hospitalisation costs with OD management after thrombolysis; and (3) videofluoroscopy as the most cost-effective screening method (compared to bedside evaluation and a combination of both). Two studies showed cost-effective rehabilitation programmes, including OD management. Pelczarska et al. showed an incremental cost–utility ratio of texture-modified diets using a gum-based thickener of 20,977 PLN (4660€) following a dynamic model, and Kotecki et al. commercially prepared thickened fluids that were 44% to 59% less expensive than in situ prepared fluids. Elia et al. showed home enteral nutrition was cost-effective (£12,817/QALY), and Beavan et al. showed higher nutrient intake and low increase in hospitalisation costs using looped-nasogastric tubes (£5.20 for every 1% increase). Heterogeneity between studies precluded a quantitative synthesis. Conclusions: Included studies suggest that healthcare interventions aiming to prevent OD complications are cost-effective. However, studies assessing novel strategies are needed.

A Novel Approach to Severe Chronic Neurogenic Dysphagia Using Pharyngeal Sensory Electrical Stimulation

ABSTRACT

The treatment options for severe chronic neurogenic dysphagia are limited. A patient, after resection of medulla oblongata hemangioblastoma, who failed to respond to 7 mos of traditional dysphagia rehabilitation therapy, was treated with prolonged pharyngeal sensory electrical stimulation for 39 sessions over 57 days. For the first time, this case report showed improvement in hypopharyngeal peak pressure (9.1 vs. 90.8 mm Hg) using high-resolution manometry. Reductions in the penetration and aspiration scale, secretion, and residue of the vallecular and pyriform sinus were verified by videofluoroscopic swallowing study and flexible endoscopic evaluation of swallowing. The Functional Oral Intake Scale score increased from 1 to 6. No adverse event was observed. This case report presented a potential therapeutic protocol for severe chronic neurogenic dysphagia, which might be instructive for clinical practice.

Toward a robust swallowing detection for an implantable active artificial larynx: a survey

Total laryngectomy consists in the removal of the larynx and is intended as a curative treatment for laryngeal cancer, but it leaves the patient with no possibility to breathe, talk, and swallow normally anymore. A tracheostomy is created to restore breathing through the throat, but the aero-digestive tracts are permanently separated and the air no longer passes through the nasal tracts, which allowed filtration, warming, humidification, olfaction, and acceleration of the air for better tissue oxygenation. As for phonation restoration, various techniques allow the patient to talk again. The main one consists of a tracheo-esophageal valve prosthesis that makes the air passes from the esophagus to the pharynx, and makes the air vibrate to allow speech through articulation. Finally, swallowing is possible through the original tract as it is now isolated from the trachea. Yet, many methods exist to detect and assess a swallowing, but none is intended as a definitive restoration technique of the natural airway, which would permanently close the tracheostomy and avoid its adverse effects. In addition, these methods are non-invasive and lack detection accuracy. The feasibility of an effective early detection of swallowing would allow to further develop an implantable active artificial larynx and therefore restore the aero-digestive tracts. A previous attempt has been made on an artificial larynx implanted in 2012, but no active detection was included and the system was completely mechanic. This led to residues in the airway because of the imperfect sealing of the mechanism. An active swallowing detection coupled with indwelling measurements would thus likely add a significant reliability on such a system as it would allow to actively close an artificial larynx. So, after a brief explanation of the swallowing mechanism, this survey intends to first provide a detailed consideration of the anatomical region involved in swallowing, with a detection perspective. Second, the swallowing mechanism following total laryngectomy surgery is detailed. Third, the current non-invasive swallowing detection technique and their limitations are discussed. Finally, the previous points are explored with regard to the inherent requirements for the feasibility of an effective swallowing detection for an artificial larynx. Graphical Abstract.

The Biomechanical Characteristics of Swallowing in Tracheostomized Patients with Aspiration following Acquired Brain Injury: A Cross-Sectional Study

Objectives: Investigate the biomechanical characteristics in tracheostomized patients with aspiration following acquired brain injury (ABI) and further explore the relationship between the biomechanical characteristics and aspiration. Methods: This is a single-center cross-sectional study. The tracheostomized patients with aspiration following ABI and age-matched healthy controls were recruited. The biomechanical characteristics, including velopharynx (VP) maximal pressure, tongue base (TB) maximal pressure, upper esophageal sphincter (UES) residual pressure, UES relaxation duration, and subglottic pressure, were examined by high-resolution manometry and computational fluid dynamics simulation analysis. The penetration−aspiration scale (PAS) score was evaluated by a videofluoroscopic swallowing study. Results: Fifteen healthy subjects and fifteen tracheostomized patients with aspiration following ABI were included. The decreased VP maximal pressure, increased UES residual pressure, and shortened UES relaxation duration were found in the patient group compared with the control group (p < 0.05). Furthermore, the subglottic pressure significantly decreased in patients (p < 0.05), while no significant difference was found in TB maximal pressure between groups (p > 0.05). In addition, in the patient group, VP maximal pressure (rs = −0.439; p = 0.015), UES relaxation duration (rs = −0.532; p = 0.002), and the subglottic pressure (rs = −0.775; p < 0.001) were negatively correlated with the PAS score, while UES residual pressure (rs = 0.807; p < 0.001) was positively correlated with the PAS score (p < 0.05), the correlation between TB maximal pressure and PAS score (rs = −0.315; p = 0.090) did not reach statistical significance. Conclusions: The biomechanical characteristics in tracheostomized patients with aspiration following ABI might manifest as decreased VP maximal pressure and subglottic pressure, increased UES residual pressure, and shortened UES relaxation duration, in which VP maximal pressure, UES relaxation duration, subglottic pressure, and UES residual pressure were correlated with aspiration.

Deglutition and the Regulation of the Swallow Motor Pattern

Despite centuries of investigation, questions and controversies remain regarding the fundamental genesis and motor pattern of swallow. Two significant topics include inspiratory muscle activity during swallow (Schluckatmung, i.e., "swallow-breath") and anatomical boundaries of the swallow pattern generator. We discuss the long history of reports regarding the presence or absence of Schluckatmung and the possible advantages of and neural basis for such activity, leading to current theories and novel experimental directions.

Evaluation of Dysphagia and Inhalation Risk in Neurologically Impaired Children Using Esophageal High-Resolution Manometry with Swallowing Analysis

BACKGROUND

Dysphagia in neurologically impaired children is associated with feeding difficulties, malnutrition and aspiration pneumonia. Esophageal high-resolution manometry (HRM) has been used in the diagnosis of motility disorders affecting the swallowing process. The aim of this study was to analyze swallowing functions in NI children by using HRM in order to establish swallow parameters identifying inhalation risk.

METHODS

Twenty-five NI children with cerebral palsy were submitted to esophageal HRM with UES analysis, comparing the results with non-NI children. The following parameters were evaluated: maximum pressure and duration of contraction of the velopharynx (VP) and tongue base (TB), and maximal, minimal, resting pressure and relaxation duration of the upper esophageal sphincter (UES).

RESULTS

pVP max, pTB max, pUES max and resting pressure were lower, while p UES minimal was higher and relaxation duration was shorter in NI children vs. the control group. Predictive values of inhalation risk were evaluated.

CONCLUSIONS

This study evaluates inhalation risk in NI children using HRM to study UES function. Our results confirm the alterations described in NI children: insufficient contraction and clearing force for bolus transmission through the pharynx and incomplete UES relaxation can predispose to pharyngeal residues and inhalation independently of swallowing because of lower values of UES resting.

Biomechanical mechanism of reduced aspiration by the Passy-Muir valve in tracheostomized patients following acquired brain injury: Evidences from subglottic pressure

Objective

Aspiration is a common complication after tracheostomy in patients with acquired brain injury (ABI), resulting from impaired swallowing function, and which may lead to aspiration pneumonia. The Passy-Muir Tracheostomy and Ventilator Swallowing and Speaking Valve (PMV) has been used to enable voice and reduce aspiration; however, its mechanism is unclear. This study aimed to investigate the mechanisms underlying the beneficial effects of PMV intervention on the prevention of aspiration.

Methods

A randomized, single-blinded, controlled study was designed in which 20 tracheostomized patients with aspiration following ABI were recruited and randomized into the PMV intervention and non-PMV intervention groups. Before and after the intervention, swallowing biomechanical characteristics were examined using video fluoroscopic swallowing study (VFSS) and high-resolution manometry (HRM). A three-dimensional (3D) upper airway anatomical reconstruction was made based on computed tomography scan data, followed by computational fluid dynamics (CFD) simulation analysis to detect subglottic pressure.

Results

The results showed that compared with the non-PMV intervention group, the velopharynx maximal pressure (VP-Max) and upper esophageal sphincter relaxation duration (UES-RD) increased significantly (P < 0.05), while the Penetration-Aspiration Scale (PAS) score decreased in the PMV intervention group (P < 0.05). Additionally, the subglottic pressure was successfully detected by CFD simulation analysis, and increased significantly after 2 weeks in the PMV intervention group compared to the non-PMV intervention group (P < 0.001), indicating that the subglottic pressure could be remodeled through PMV intervention.

Conclusion

Our findings demonstrated that PMV could improve VP-Max, UES-RD, and reduce aspiration in tracheostomized patients, and the putative mechanism may involve the subglottic pressure.

Clinical trial registration

[http://www.chictr.org.cn], identifier [ChiCTR1800018686].

The Natural Swallow: Factors Affecting Subject Choice of Bolus Volume and Pharyngeal Swallow Parameters in a Self-selected Swallow

Predetermined volumes are used extensively throughout clinical assessment of swallowing physiology, but bolus volumes selected by an individual in their natural swallow can vary greatly from those used in structured assessment. This study aims to identify factors influencing self-selected volume and how the mechanics of self-selected volume swallows differ from predetermined volume swallows. We used pharyngeal high-resolution manometry (HRM) with simultaneous videofluoroscopy to measure swallowing pressures in the velopharynx, hypopharynx, and upper esophageal sphincter (UES). Data were collected from 95 healthy adults during thin liquid swallows of 10 mL and a self-selected comfortable volume. An intraclass correlation coefficient (ICC) was calculated to analyze within-subject self-selected volume reliability. Linear mixed effects regression models were used to examine the association of subject characteristics with self-selected swallow volume and of self-selected volumes on pharyngeal swallowing pressures and timing events. Mean self-selected volume was 16.66 ± 7.70 mL. Increased age (p = 0.002), male sex (p = 0.021), and increased pharyngeal hold area (p = 0.007) were significantly associated with increase in self-selected bolus volume. There was good reliability between subjects' individual swallow volumes (ICC = 0.80). Velopharyngeal maximum pressure and pressure integral, tongue base duration and maximum pressure, UES pre- and post-swallow maximum pressure, and overall pharyngeal contractile integral decreased significantly with self-selected boluses. Understanding a patient's natural swallow volume, and how their natural swallow functions, will be important for designing clinical evaluations that place stress on the patient's natural swallowing mechanics in order to assess for areas of dysfunction.

Comparison of methods for evaluation of upper esophageal sphincter (UES) relaxation duration: Videofluoroscopic swallow study versus high-resolution manometry

This study aims to compare the 2 methods of upper esophageal sphincter (UES) relaxation measurement and determine which method has better diagnostic value in UES relaxation impairment The study included 140 patients with pharyngeal dysphagia who underwent both videofluoroscopic swallow study (VFSS) and high-resolution manometry (HRM). Feeding method was determined to oral or non-oral feeding based on the severity of dysphagia; 103 patients were in oral feeding group and 37 were in non-oral feeding group. UES relaxation duration was measured using VFSS and HRM, respectively. Receiver-operating characteristic curve analysis was conducted to validate the UES relaxation duration in determination of feeding method. UES relaxation duration was more decreased in non-oral feeding group than in oral feeding group on both VFSS and HRM. Receiver-operating characteristic analysis revealed that the optimal cutoff value of UES relaxation duration to determine feeding method (oral or non-oral feeding) was 0.42 seconds on VFSS and 0.44 seconds on HRM. The sensitivity for feeding method was higher in VFSS than HRM (83.5% vs 70.9%), while the specificity was higher in HRM than VFSS (48.6% vs 54.1%). VFSS and HRM have complementary ability in evaluating UES relaxation duration in patients with oropharyngeal dysphagia.

Pharyngeal Pressure Variability During Volitional Swallowing Maneuvers

PURPOSE

Within-individual pharyngeal swallowing pressure variability differs among pharyngeal regions in healthy individuals and increases with age. It remains unknown if pharyngeal pressure variability is impacted by volitional swallowing tasks. We hypothesized that pressure variability would increase during volitional swallowing maneuvers and differ among pharyngeal regions depending on the type of swallowing task being performed.

METHOD

Pharyngeal high-resolution manometry was used to record swallowing pressure data from 156 healthy participants during liquid (5 cc) or saliva swallows, and during volitional swallowing tasks including effortful swallow, Mendelsohn maneuver, Masako maneuver, or during postural adjustments. The coefficient of variation was used to determine pressure variability of velopharynx, tongue base, hypopharynx, and upper esophageal sphincter regions. Repeated-measures analysis of variance was used on log-transformed data to examine effects of pharyngeal region and swallowing tasks on swallow-to-swallow variability.

RESULTS

There was a significant main effect of task with greater pressure variability for the effortful swallow (p = .002), Mendelsohn maneuver (p < .001), Masako maneuver (p = .002), and the head turn (p = .006) compared with normal effort swallowing. There was also a significant main effect of region (p < .01). In general, swallowing pressure variability was lower for the tongue base and upper esophageal sphincter regions than the hypopharynx. There was no significant interaction of task and region (effortful, p = .182; Mendelsohn, p = .365; Masako, p = .885; chin tuck, p = .840; head turn, p = .059; and inverted, p = .773).

CONCLUSIONS

Pharyngeal swallowing pressure variability increases in healthy individuals during volitional swallowing tasks. Less stable swallow patterns may result when tasks are less automatic and greater in complexity. These findings may have relevance to swallowing motor control integrity in healthy aging and individuals with neurogenic dysphagia.

Effect of Topical Nasal Anesthetic on Comfort and Swallowing in High-Resolution Impedance Manometry

OBJECTIVES/HYPOTHESIS

Use of topical nasal anesthetic (TNA) is common in high-resolution impedance manometry (HRIM). This study investigated the effect of TNA on swallowing and procedure tolerability during HRIM with a 4.2-mm catheter, a more commonly used catheter size with impedance capabilities.

STUDY DESIGN

Randomised experimental study with blinding of participants.

METHODS

Twenty healthy participants (mean age = 33 years, 16 female) were randomized to undergo HRIM using the ManoScan™ ESO Z 4.2-mm catheter twice, 1 week apart, under two conditions: with TNA (viscous lidocaine) and with placebo. Analyses included esophageal data of three saliva, three saline (5 mL), and three bread swallows (2 cm × 2 cm) performed while reclined 45°, and pharyngeal data under the same conditions while seated upright. Pharyngeal and upper esophageal sphincter (UES) HRIM parameters were analyzed using the Swallow Gateway analysis platform. Visual analogue scale (VAS) scores rating procedural comfort were analyzed.

RESULTS

There were no significant physiological differences in pharyngeal and UES parameters between conditions. There were also no significant differences in VAS scores under placebo (mean = 54.8, standard deviation (SD) = 19.3) and TNA (mean = 60.0, SD = 21.9) (t[19] = -0.9, P = .4) conditions; however, there was a significant difference in the first versus second session (t[19]) = 5.1, P < .05).

CONCLUSIONS

TNA did not improve comfort, but it also did not significantly affect swallowing behavior. There was, however, a practice effect regardless of TNA use with improved tolerance of the 4.2-mm catheter and likely more natural swallowing behavior during the second session of HRIM.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

Can Videofluoroscopic Swallowing Kinematic Analysis Predict Recovery of Oral Intake in Postoperative Oral Cancer Patients Requiring Nasogastric Tube Feeding?

This retrospective study determined the significant predictive factors for the number of days required to remove nasogastric tubes (NGTs) after surgery in patients with oral cancer (OC). In this study, patients underwent a videofluoroscopic swallowing study (VFSS) approximately 2 weeks after surgery. Videofluoroscopic images were analyzed, and variables such as swallowing and swallowing kinematics were measured. Patient characteristics, swallowing kinematics, and swallowing results were assessed using a Cox proportional hazards model. This study assessed 129 participants (66 men, 63 women, mean age: 69.0 ± 14.1 years) with nine types of cancer. The Cox proportional hazard ratio revealed that sex, body mass index before surgery, radiotherapy and/or chemotherapy, dysphagia before surgery, normalized pharyngeal constriction ratio, upper esophageal sphincter (UES) opening, and laryngeal vestibule disclosure (LVC) disorder were predictive factors for the removal of NGTs when adjusted for age. The study identified several predictive factors for the removal of NGTs and oral intake recovery in patients with OC. Regarding swallowing kinematics, UES opening is the most significant predictive factor. After surgery for OC, VFSS should be performed to assess safe eating methods and predict the recovery of oral intake and removal of the NGT.

Blowing time ratio and high-resolution manometry to evaluate swallowing function of patients with oral and oropharyngeal cancer

OBJECTIVE

The blowing time ratio, which is the ratio of the blowing time when the nostrils are open and closed, is significantly correlated with velopharyngeal pressure, not only during speech but also during swallowing. This study aimed to further evaluate the usefulness of the blowing time ratio as a screening tool to evaluate the swallowing pressure of patients treated for oral and oropharyngeal cancers using high-resolution manometery (HRM).

METHODS

Ten patients treated for oral or oropharyngeal cancer were recruited for this study. Swallowing pressures at the velopharynx, oropharynx, and upper esophageal sphincter (UES) were measured using HRM. Their correlations with the blowing time ratio were analyzed.

RESULTS

The blowing time ratio was significantly correlated with the swallowing pressures of the oropharynx (CC = 0.815, p = 0.004) and the velopharynx (CC = 0.657, p = 0.039), but not of the UES.

CONCLUSIONS

The present results further support our previous finding that the blowing time ratio is a useful screening tool to evaluate velopharyngeal and oropharyngeal swallowing pressures in patients treated for oral and oropharyngeal cancer.

PHARYNGEAL, UPPER ESOPHAGEAL SPHINCTERIC AND ESOPHAGEAL PRESSURES RESPONSES RELATED TO VOCAL TASKS AT THE LIGHT OF HIGH RESOLUTION MANOMETRY

BACKGROUND

High-resolution manometry (HRM) represents a potential tool for measuring pharyngoesophageal phonation pressures.

OBJECTIVE

This study aims to evaluate pharyngeal, esophageal upper sphincteric and esophageal pressures during different phonation tasks.

METHODS

12 (six males, mean age 27 years) professional singers underwent HRM and produced four different vocal tasks at low, medium and high vocal loudness: vowel /ae/, ascending five note scale, word /hey/ and word /go/. Pressures were measured at pharynx, upper esophageal sphincter (UES) and esophagus. Visual analysis of the HRM topographic plots were performed.

RESULTS

Esophageal pressures are higher during vocalization than at rest. Pharyngeal and UES phonation pressures does not differ significantly from rest pressures. Visual analysis of the topographic plots showed an important UES pressure increasement during phonation.

CONCLUSION

HRM is a valuable tool for measuring pharyngoesophageal pressures during phonation. Esophageal pressures are higher during phonation than at rest and tend to increase with vocal loudness increment. The topographic plot provides additional data about phonatory mechanism physiology, especially at the UES region.

Mechanisms and management considerations of parent-chosen feeding approaches to infants with swallowing difficulties: an observational study

Videofluoroscopy swallow studies (VFSS) and high-resolution manometry (HRM) methods complement to ascertain mechanisms of infant feeding difficulties. We hypothesized that: (a) an integrated approach (study: parent-preferred feeding therapy based on VFSS and HRM) is superior to the standard-of-care (control: provider-prescribed feeding therapy based on VFSS), and (b) motility characteristics are distinct in infants with penetration or aspiration defined as penetration-aspiration scale (PAS) score ≥ 2. Feeding therapies were nipple flow, fluid thickness, or no modification. Clinical outcomes were oral-feeding success (primary), length of hospital stay and growth velocity. Basal and adaptive HRM motility characteristics were analyzed for study infants. Oral feeding success was 85% [76-94%] in study (N = 60) vs. 63% [50-77%] in control (N = 49), p = 0.008. Hospital-stay and growth velocity did not differ between approaches or PAS ≥ 2 (all P > 0.05). In study infants with PAS ≥ 2, motility metrics differed for increased deglutition apnea during interphase (p = 0.02), symptoms with pharyngeal stimulation (p = 0.02) and decreased distal esophageal contractility (p = 0.004) with barium. In conclusion, an integrated approach with parent-preferred therapy based on mechanistic understanding of VFSS and HRM metrics improves oral feeding outcomes despite the evidence of penetration or aspiration. Implementation of new knowledge of physiology of swallowing and airway protection may be contributory to our findings.

Spectral arc length as a method to quantify pharyngeal high-resolution manometric curve smoothness

BACKGROUND

Pharyngeal high-resolution manometry (HRM) has emerged over the last decade as a valuable assessment tool for oropharyngeal dysphagia. Data analysis thus far has focused primarily on measures of pressure and duration within key anatomic regions. We apply spectral arc length (SPARC), a dimensionless metric for quantifying smoothness felt to indirectly reflect neuromuscular coordination, as a new method of describing manometric curves. We then use it to distinguish swallows from healthy subjects and those with dysphagia related to stroke.

METHODS

Previously collected pharyngeal HRM data from eight subjects with history of stroke and eight age- and sex-matched controls were reviewed. Receiver operating characteristic (ROC) analysis was used to optimize SPARC inputs. SPARC was then computed for the velopharynx, tongue base, hypopharynx, and upper esophageal sphincter (UES), and the values were compared between the two subject groups.

RESULTS

Optimized parameter settings yielded an ROC curve with area under the curve (AUC) of 0.953. Mean SPARC values differed between control and stroke subjects for the velopharynx (t = 3.25, p = 0.0058), tongue base (t = 4.77, p = 0.0003), and hypopharynx (t = 2.87, p = 0.0124). Values were similar for the UES (t = 0.43, p = 0.671).

CONCLUSIONS

In this preliminary study, SPARC analysis was applied to distinguish control from post-stroke subjects. Considering alternative methods of analyzing pharyngeal HRM data may provide additional insight into the pathophysiology of dysphagia beyond what can be gleaned from measures of pressure and duration alone.

Measurement of Pharyngeal Air Pressure During Phonation Using High-Resolution Manometry

Purpose The study of air pressure in the vocal tract is essential to understanding vocal function. Changes in vocal tract shape during different phonatory gestures are hypothesized to produce nonuniform air pressure across lower vocal tract locations. Current methods of air pressure measurement, however, are limited to a single location in the anterior oral cavity. The purposes of this study were (a) to assess the feasibility of a novel method of simultaneously measuring phonatory air pressure at multiple locations across the lower vocal tract using high-resolution pharyngeal manometry (HRM) and (b) to compare pressure across locations and among phonatory tasks. Method Two subjects underwent HRM while performing phonatory tasks. A catheter was passed transnasally and air pressure was measured simultaneously at five locations between the velopharyngeal port and the upper esophageal sphincter. Descriptive statistics were calculated for each location by task, and for each task averaged across locations. Results HRM was well tolerated, and air pressures from multiple locations in the lower vocal tract were able to be obtained simultaneously. During vocal tract semi-occlusion tasks, air pressures differed by location. Pressures averaged across locations demonstrated a pattern of increasing pressure with increasing semi-occlusion. Conclusions HRM is feasible for measuring air pressure simultaneously at multiple locations in the lower vocal tract during phonation with high spatial and temporal resolution, providing rich data to augment understanding of vocal function. The high spatial and temporal resolution yielded by this new method, paired with preliminary evidence that pressures change by location as a function of phonatory task, may be useful in future assays exploring differences in lower vocal tract air pressures between normal and disordered populations.

Impact of the Chin-Down Posture on Temporal Measures of Patients With Dysphagia: A Pilot Study

Purpose The chin-down position is a commonly prescribed posture by health care professionals to alleviate the symptoms of dysphagia. Yet, how the technique influences swallowing physiology lacks clarity. Our goal was to examine the impact of the postural technique on patients with various medical conditions and swallowing impairments. Method Temporal and functional measures were examined with videofluoroscopy in the chin-down and neutral head position on 15 patients. Also, timing differences between head positions were examined to determine the presence of improvement during the chin-down posture. Results The primary finding was chin-down posture swallows prolonged the elapsed time between when the prematurely spilled bolus entered the pharynx relative to swallow onset compared to the neutral head position (p = .006). Also, no improvement in airway protection was found when performing the postural technique. Conclusions The chin-down posture may benefit patients with specific swallowing impairments. However, the general use of the technique for all patients who experience swallowing difficulty might be negligent and could potentially have adverse or no effect on patient outcomes. Future studies examining patients with the same pathophysiology are needed to understand the benefit of the chin-down posture based on swallowing impairment.

The Effect of Combined Guidance of Botulinum Toxin Injection with Ultrasound, Catheter Balloon, and Electromyography on Neurogenic Cricopharyngeal Dysfunction: A Prospective Study

BACKGROUND

Cricopharyngeal botulinum toxin (BTX) injection is one of the treatments for neurogenic cricopharyngeal dysfunction (CPD). We conducted this prospective study to investigate the effect and safety of BTX injection for neurogenic CPD with a novel guidance.

METHODS

Twenty-one patients with neurogenic CPD whose symptoms did not reduce after conventional swallowing therapy were included in this study. The impact of BTX injection on the swallowing function of the patients was evaluated.

KEY RESULTS

After the injection, the Functional Oral Intake Scale (FOIS) score increased in 17 of 21 patients (80.9%), which ranged from 1 to 3 (P < 0.001). Moreover, there was a significant reduction in the UES opening impairment (P < 0.01), UES residual pressure (P < 0.05), duration of UES relaxation, penetration-aspiration scale score (P < 0.05), secretion (P < 0.05), vallecular residue (P < 0.01), and left (P < 0.05) and right (P < 0.05) pyriform sinus residue. With at least 6 months of follow-up, we found that FOIS continued to increase in patients who showed improvement after the injection (i.e., FOIS 5-7 points), while it remained unchanged in patients without improvement after the injection. There were no side effects reported in this study.

CONCLUSION & INFERENCES

BTX injection into the cricopharyngeal muscle guided by ultrasound, catheter balloon, and electromyography possibly has a long-lasting effect that can effectively and safely improve the swallowing function of patients with neurogenic CPD.

Adequate Number of Swallows for Pharyngeal Pressure Measurement of a Subject using High-resolution Manometry

Introduction  The number of pressure measurements that need to be recorded using high-resolution manometry (HRM) for the accurate evaluation of pharyngeal function is not well established.

Objective  The purpose of this study is to clarify the number of swallows required to obtain an accurate pharyngeal manometric profile of a person.

Methods  Forty healthy adults performed a dry swallow and bolus swallows using 3-, 5-, or 10 ml of water and underwent measurements using the Starlet HRM system. Each subject underwent 10 swallows for each of the four bolus volume conditions.

Results  The mean of up to seven measurements of maximum pre-swallow upper esophageal sphincter pressure with 10 ml of swallow was close to the mean of up to eight measurements in 95% of the subjects. Similarly, the rate of change of the average for the eighth and ninth measurements and the rate of change for the average of the ninth and tenth measurements were less than 5%. When the other parameters were similarly measured up to the sixth measurement, no major change in the average value was observed even if more measurements were taken.

Conclusion  A minimum of six measurements are required, and seven swallows are sufficient for evaluating the pharyngeal manometric profile of a single person. This number of measurements can be a useful criterion when performing HRM measurements on individual subjects.

Effects of Chin-Down Maneuver on Pharyngeal Pressure Generation According to Dysphagia and Viscosity

Objective

To demonstrate the effects of chin-down maneuver on swallowing by using high-resolution manometry (HRM).

Methods

HRM data of 20 healthy subjects and 64 dysphagic patients were analyzed. Participants swallowed 5 mL of thin and honey-like liquids in neutral and chin-down positions. HRM was used to evaluate maximal velopharyngeal pressure/area, maximal tongue base pressure/area, maximal pharyngeal constrictor pressure, pre-/post-swallow upper esophageal sphincter (UES) peak pressure, minimal UES pressure, UES activity time, and nadir duration.

Results

Compared to the neutral position, the chin-down maneuver significantly increased tongue base pressure in both normal and dysphagic groups as well as for both honey-like and thin viscosities, although the honey-like liquid did not reach statistical significance in the dysphagic group. Regarding pharyngeal constrictors and pre-swallow peak UES pressure, the healthy group showed a significant decrease in thin liquid swallowing and decreasing tendency in honeylike liquid swallowing. UES nadir duration was significantly decreased for honey-like liquid swallowing in the dysphagic group and for both thin and honey-like liquids in the healthy group. UES nadir duration of honey-like and thin flow swallowing in the dysphagia group was 0.26 seconds after the chin-down maneuver, which was severely limited.

Conclusion

This study showed a different kinetic effect of the chin-down maneuver between the healthy and dysphagic groups, as well as between thin and honey-like viscosities. The chin-down maneuver increased tongue base pressure and decreased UES nadir duration, which the latter was severely limited in dysphagic patients. Therefore, appropriate application of the chin-down maneuver in clinical practice is required.

Effect of Tongue-Hold Swallow on Pharyngeal Contractile Properties in Healthy Individuals

Tongue-hold swallow (THS) is a swallow exercise in which an individual swallows saliva while holding the anterior portion of the tongue between the front teeth. The effect of THS on pharyngeal contractile vigor is still unclear. The purpose of this study was to quantify THS using high-resolution manometry with a contractile integral analysis. Twenty-two healthy participants performed three different saliva swallow tasks: normal swallow, weak THS (in which the tongue was protruded 1 cm outside the upper incisors), and strong THS (in which the tongue was protruded 2 cm outside the upper incisors). The participants repeated each task twice randomly. Pharyngeal and upper esophageal sphincter metrics, including the pharyngeal contractile integral, were analyzed. Both weak and strong THS enhanced the velopharyngeal contractile integral and peak pressure compared with normal swallow (P < 0.01). THS also prolonged mesopharyngeal contraction (P < 0.01). Holding the tongue anteriorly during swallow requires significant biomechanical changes to pharyngeal contractile properties at the superior and middle pharyngeal constrictor levels; thus, it may serve as a resistance exercise for the muscles that are involved in bolus propulsion.

Evaluation of the pharynx and upper esophageal sphincter motility using high-resolution pharyngeal manometry for Parkinson's disease

Parkinson's disease (PD) is associated with a high incidence of dysphagia. Aspiration pneumonia due to dysphagia is a major cause of death in patients with PD, and therefore accurately evaluating dysphagia should help improve prognosis. It has been reported that the severity of dysphagia does not always correlate with the Hoehn and Yahr (H&Y) stage for classifying PD severity. However, no reports have quantitatively evaluated the relationship between severity of dysphagia and H&Y stage. High-resolution pharyngeal manometry (HRPM) is a quantitative method that can be used to measure swallowing pressure from the velopharynx to the entry of the upper esophageal sphincter (UES). We used HRPM to measure swallowing pressure in 51 patients with PD. As PD progresses, atrophy and degeneration of the pharyngeal muscles become more pronounced, which contributes to dysphagia. However, thus far there is no quantitative clinical evidence for this pathological change. To evaluate the relationship between severity of underlying PD and dysphagia, patients were categorized by H&Y stage, as follows: stage II in four patients, stage III in 23, stage IV in 14, and stage V in 10. In patients with H&Y stages II, III, IV, and V, the respective velopharyngeal pressures were 179.8 ± 32.5, 157.6 ± 62.2, 172.2 ± 48.9, and 107.4 ± 44.0 mmHg, the mesopharyngeal pressures were 126.8 ± 53.2, 121.6.1 ± 50.4, 142.1 ± 57.8, and 61.4 ± 19.6 mmHg, the residual UES pressure were -8.0 ± 10.8, 10.3 ± 16.1, 16.5 ± 37.9, and 11.2 ± 16.2 mmHg, and the resting UES pressure were 49.5 ± 30.0, 15.8 ± 25.7, 1.85 ± 14.1, and -1.2 ± 12.2 mmHg. Patients with severe PD demonstrated significantly decreased velopharyngeal and oropharyngeal pressures, along with incomplete UES opening and contraction. HRPM can detect subtle abnormalities by quantifying swallowing pressure in patients with PD. Evaluating swallowing pressure with HRPM provides insights into neuromuscular dysfunction that causes abnormal pressure generation during pharyngeal swallowing in patients with PD.

Aspects of the assessment and management of pharyngoesophageal dysphagia

Swallowing complaints are common and may have significant consequences for nutrition and pulmonary health. Etiology varies and different aspects of the deglutitive system may be affected. A thorough assessment from the oral cavity to the stomach will provide physiologic information that enables specific targeted management plans to be devised. Although the swallow trajectory bridges anatomic areas, there has previously been a tendency to compartmentalize assessment and treatment by arbitrary anatomic boundaries. It is now clear that this approach fails to appreciate the complexity of swallow mechanics and that systems (oral, pharyngeal, esophageal, and pulmonary) are intertwined and codependent. Swallowing specialists from different backgrounds and with complementary skill sets form a multidisciplinary team that can provide insight and address multiple areas of management. With the advent of new tools for instrumental evaluation, such as manometry, targeted rehabilitative strategies can be informed by physiology, increased in precision and breadth, and assessed quantitatively. Surgical approaches have evolved toward endoscopic techniques, and food technology is expanding options in dietary management. The multidisciplinary team is core to managing this varied and often neglected patient population. This review is for clinicians treating swallowing disorders and will explore the selected aspects of the assessment and management of pharyngoesophageal swallowing disorders.

Motor Learning, Neuroplasticity, and Strength and Skill Training: Moving From Compensation to Retraining in Behavioral Management of Dysphagia

Purpose Learning a motor skill and regaining a motor skill after it is lost are key tenets to the field of speech-language pathology. Motor learning and relearning have many theoretical underpinnings that serve as a foundation for our clinical practice. This review article applies selective motor learning theories and principles to feeding and swallowing across the life span. Conclusion In reviewing these theoretical fundamentals, clinical exemplars surrounding the roles of strength, skill, experience, compensation, and retraining, and their influence on motor learning and plasticity in regard to swallowing/feeding skills throughout the life span are discussed.

KSNR Clinical Consensus Statements: Rehabilitation of Patients with Parkinson's Disease

Clinical consensus statements (CCSs) aim to improve care for patients with Parkinson's disease (PD) and reduce the variability of rehabilitation methods in clinical practice. A literature search was conducted to find available evidence on the rehabilitation of patients with PD and to determine the scope of CCSs. The selection of PD rehabilitation domains and key questions was done using the modified Delphi method in 43 expert panels. These panels achieved a consensus on 11 key questions regarding rehabilitation assessment and goal setting, gait and balance, activities of daily living, and swallowing and communication disorders. After the completion of an agreement procedure, 11 key consensus statements were developed by the consensus panel. These statements addressed the needs of rehabilitation as a continuum in patients with PD. They included the appropriate rehabilitation initiation time, assessment items, rehabilitation contents, and complication management. This agreement can be used by physiatrists, rehabilitation therapists, and other practitioners who take care of patients with PD. The consensus panel also highlighted areas where a consensus could not be reached. The development of more focused CCS or clinical practice guidelines that target specific rehabilitation approaches is considered the next needed step.

Pharyngeal Swallowing Pressures in Patients with Radiation-Associated Dysphagia

Dysphagia associated with radiotherapy for head and neck cancer is complex and can be difficult to treat. Videofluoroscopic swallow studies (VFSS) are the current gold-standard instrumented swallow assessment. High-resolution manometry (HRM) is an additional approach that provides objective measurements of swallowing-related pressures in the pharynx and esophagus. This can provide functional information on the pressure gradients underlying bolus propulsion, and is relevant for this patient population, where radiation-related fibrosis can lead to weakness and impaired pressure generation. The purpose of this preliminary study was to describe pharyngeal swallowing pressures in patients with radiation-associated dysphagia (RAD) and late radiation-associated dysphagia (LRAD) using HRM. RAD occurs during and immediately following treatment, whereas LRAD is a more recently described phenomenon in which the patient experiences an onset of dysphagia at least 5 years post-treatment. We performed a retrospective analysis of pharyngeal swallowing pressures from 21 patients with RAD or LRAD and 21 healthy sex/age-matched controls. Patients with RAD or LRAD exhibited decreased swallowing pressure durations throughout the pharynx (p ≤ 0.002), as well as decreased hypopharynx maximum pressure (p = 0.003) and pharyngeal contractile integral ( p < 0.0001). Understanding how pharyngeal pressure generation is altered in patients with a history of radiotherapy can help clinicians form more precise treatment plans.

Swallowing Pressure Variability as a Function of Pharyngeal Region, Bolus Volume, Age, and Sex

OBJECTIVES

Within-individual movement variability occurs in most motor domains. However, it is unknown how pharyngeal swallowing pressure varies in healthy individuals. We hypothesized that: 1) variability would differ among pharyngeal regions; 2) variability would decrease with increased bolus volume; 3) variability would increase with age; and 4) there would be no sex differences.

STUDY DESIGN

Case series.

METHODS

We used pharyngeal high-resolution manometry to measure swallowing pressure in the following regions: velopharynx, tongue base, hypopharynx, and upper esophageal sphincter. Data were collected from 97 healthy adults (41 male) aged 21 to 89 years during thin liquid swallows: 2 mL, 10 mL, and participant-selected comfortable volume. Pressure variability was measured using coefficient of variation. Repeated measures analysis of variance was used to assess impacts of region, bolus volume, age, and sex on pressure variability.

RESULTS

There was a significant region × volume interaction (P < .001) and significant main effect of age (P = .005). Pressures in the hypopharynx region were more variable than all other regions (P ≤ .028), and pressures in the tongue base region were less variable than all other regions (P ≤ .002) except at 2 mL volumes (P = .065). Swallowing pressure variability was significantly different in the velopharynx and upper esophageal sphincter regions, with comfortable volume and 2 mL swallows having greater variability than 10 mL swallows (P ≤ .026). Pressure variability significantly increased with increasing age (P = .002). There were no effects of sex on pressure variability (P ≥ .15).

CONCLUSION

Pharyngeal swallowing pressure variability differs according pharyngeal region, volume, and age but not sex. Abnormal swallowing pressure variability may reflect deviations in motor control in persons with swallowing impairment, and results from this study can be used as normative data for future investigations evaluating swallowing pressure generation.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E52-E58, 2021.

Artificial Intelligence Applied to Gastrointestinal Diagnostics: A Review

Artificial intelligence (AI), a discipline encompassed by data science, has seen recent rapid growth in its application to healthcare and beyond, and is now an integral part of daily life. Uses of AI in gastroenterology include the automated detection of disease and differentiation of pathology subtypes and disease severity. Although a majority of AI research in gastroenterology focuses on adult applications, there are a number of pediatric pathologies that could benefit from more research. As new and improved diagnostic tools become available and more information is retrieved from them, AI could provide physicians a method to distill enormous amounts of data into enhanced decision-making and cost saving for children with digestive disorders. This review provides a broad overview of AI and examples of its possible applications in pediatric gastroenterology.

Three-dimensional imaging of upper esophageal sphincter resting pressure

OBJECTIVE

High-resolution manometry (HRM) is used to analyze upper esophageal sphincter (UES) physiology. Conventional HRM can yield imprecise measurements of UES resting pressure given its unidirectional sensors and averaging of circumferential pressure. In contrast, three-dimensional (3D) measurements can yield precise UES resting pressure data over the entire length of the UES. This study conducted a detailed analysis of UES resting pressure as evaluated by 3D-HRM.

METHODS

Seventeen young, healthy adult participants (7 females and 10 males) were recruited. The 3D-HRM system used includes a pressure sensor catheter (outer diameter, 4 mm) and eight-channel transducers arranged circumferentially to acquire pressure data at 45° intervals. The catheter was inserted transnasally into the esophagus and automatically retracted at a speed of 1 mm/s. Participants performed the following tasks: maintain resting breathing, perform breath holding, and perform the Valsalva maneuver. Data were obtained and compared per millimeter over the longitudinal UES length.

RESULTS

Clear 3D waveforms were identified, with greater mean UES pressures in anterior-posterior directions than in lateral directions (P < .05). The anterior distribution was located superior to the posterior portion. Significant differences were observed in mean UES pressures and UES resting integrals between resting breathing and the Valsalva maneuver (P < 0.05). No differences in functional UES length were observed.

CONCLUSIONS

The normal UES resting pressure was not directionally uniform in the luminal structure. 3D-HRM imaging of UES resting pressure can help deepen our understanding of UES physiology.

LEVEL OF EVIDENCE

4.

Deglutition in Patients With Hypernasality Associated With Unilateral Cleft Lip and Palate Evaluated With High-Resolution Manometry

Objective:

To evaluate pharyngeal pressure profiles during swallowing in patients with unilateral cleft lip and palate (UCLP) and identify compensation mechanisms.

Design:

Prospective experimental study.

Setting:

University Hospital and Medical School.

Participants:

Ten volunteers and 10 patients with nonsyndromic repaired UCLP with hypernasality (age: 19-27 years, 5 females and 5 males per group) were included.

Interventions:

All participants swallowed 2 and 10 mL of water and underwent high-resolution manometry (HRM).

Main Outcome Measures:

Pharyngeal and upper esophageal sphincter (UES) parameters were measured using HRM. Student t test was used for statistical intergroup comparisons. Additionally, the Sydney Swallowing Questionnaire (SSQ) was used as a subjective measure.

Results:

Patients exhibited reduced velopharyngeal closing pressure and velopharyngeal and tongue base (TB) region contraction times, compared to volunteers ( P < .05). The UES opening and closing functions did not change. The SSQ revealed nasal regurgitation in some patients.

Conclusions:

In patients with UCLP, velopharyngeal region alterations are caused by impaired muscle force and function. The reduced TB contraction time may be a compensation mechanism allowing bolus transportation without nasal regurgitation. However, deglutition is not completely altered since UES function remains normal. Future studies will need to reveal at which point a decrease in velopharyngeal closing pressure will result in velopharyngeal insufficiency.

Elicitation of the Swallowing Reflex by Esophageal Stimulation in Healthy Subjects: An Evaluation Using High-Resolution Manometry

The purposes of this human study using high-resolution manometry were to verify whether the swallowing reflex can be evoked by intra-esophageal fluid injection and whether the reflex latency and manometric variables differ depending on the injected location, amount, or speed. Ten healthy individuals participated in this study. The tip of the intranasal catheter for injection was placed at 5 cm (upper), 10 cm (upper-middle), 15 cm (lower-middle), or 20 cm (lower) from the distal end of the upper esophageal sphincter (UES). An intra-esophageal injection of 3 mL or 10 mL of thickened water was administered and controlled at 3 mL/s or 10 mL/s. Latencies from the start of the injection to the onset of UES relaxation were compared regarding injection locations, amounts, and rates. Manometric variables of intra-esophageal injection and voluntary swallowing were compared. The latency became shorter when the upper region was injected. Latency after the 10-mL injection was shorter than that after the 3-mL injection (p < 0.01) when faster injection (10 mL/s) was used. Faster injection induced shorter latency (p < 0.01) when a larger volume (10 mL) was injected. Pre-maximum and post-maximum UES pressures during voluntary swallowing or during spontaneous swallowing when injecting the upper esophageal region were significantly higher than spontaneous swallowing at other regions (p < 0.01). Intra-esophageal fluid injection induces the swallowing reflex in humans. The most effective condition for inducing the swallowing reflex involved a larger fluid amount with a faster injection rate in the upper esophagus.

Swallowing Disorders in the Older Population

Swallowing problems, or dysphagia, are common as people age, and are associated with significant negative outcomes, including weight loss, pneumonia, dehydration, shortened life expectancy, reduced quality of life, and increased caregiver burden. In this article, we will discuss the complex process of swallowing in normal circumstances and with healthy aging, then review etiologies that contribute to dysphagia. We will discuss approaches to evaluating and treating dysphagia, providing relevant data where they are available. We highlight the desperate need for high-quality research to guide best practices in treating dysphagia in older adults. J Am Geriatr Soc 67:2643-2649, 2019.

Pharyngeal contractile and regulatory characteristics are distinct during nutritive oral stimulus in preterm-born infants: Implications for clinical and research applications

BACKGROUND

Maturation of pharyngeal swallowing during neonatal oral feeding is unknown. Our objective was to evaluate pharyngeal functioning using high-resolution manometry (HRM) during nutritive oral stimulus and test the hypothesis that pharyngeal contractility and regulation are distinct in preterm-born infants.

METHODS

High-resolution manometry data during oral milk feeding were analyzed for pharyngeal contractile (PhCI, mm Hg cm s) and regulatory (number and frequency of pharyngeal contractions and bursts, pharyngeal activity-to-quiescence ratio, upper esophageal sphincter nadir pressure) characteristics in 23 preterm (<38 weeks' gestation) and 18 full-term-born infants at term maturation. Mixed linear models and stepwise regression methods were used.

RESULTS

Despite more oral feeding experiences (P < 0.05), preterm infants (vs full-term), consumed less milk volume (P < 0.001), had lesser pharyngeal contractions within bursts (P = 0.04), lower pharyngeal contraction frequency (P < 0.01), and lower pharyngeal activity (P = 0.03), but higher PhCI per individual contraction (P = 0.01). PhCI is higher for longer PMA (P < 0.05), higher UES nadir pressures (P < 0.05), and lower pharyngeal contraction frequency (P < 0.05).

CONCLUSIONS

Nutritive oral milk stimulus provoked pharyngeal contractility characteristics is distinct in preterm-born. Despite more oral nutritive experiences, preterm infants had underdeveloped excitatory and inhibitory rhythmic activity. Cranial nerve IX and X effects on sensory-motor responses and feedback (excitation-inhibitory rhythm regulation) remain immature among preterm-born even at full-term maturational status. We speculate the relationship between PhCI and UES regulatory activity contributes to the observed differences in preterm and full-term infants.