Kinematic and temporal factors associated with penetration-aspiration in swallowing liquids

Hyoid displacement during swallowing function for completely edentulous subjects rehabilitated with mandibular implant retained overdenture

BACKGROUND

Hyoid bone is attached to the mandible, tongue, larynx, temporal bone, and cervical spine via different types of muscles or ligaments. The tongue, mandible, and hyoid system play a crucial role in swallowing function. This within subject study aimed to evaluate the impact of mandibular implant overdentures on the displacement of the hyoid bones during the swallowing process.

METHODS

Twenty five healthy edentulous subjects were selected for participating in the study. New complete dentures were constructed for all the participants. Subsequently two dental implants were inserted in the canine regions of the participant's mandibular arch. In order to retain the mandibular prosthesis in place, ball attachments were incorporated into the mandibular dentures to convert them into implant overdentures. Using 10 ml of thin liquid bolus, videofluoroscopy swallowing examination was performed in three different oral conditions: without complete dentures (WCD), with complete denture (CDs), and with a mandibular implant overdenture (IODs). ANOVA with Bonferroni test was used to analyze the data in order to determine how the hyoid displacement varied throughout different oral conditions.

RESULTS

Compared to complete dentures, mandibular implant overdentures showed a significant decrease (P < 0.05) in both anterior hyoid displacement and duration of hyoid maximum anterior excursion (DOHMAE). However, there was a non-significant difference (P > 0.05) between the two oral circumstances in terms of superior hyoid displacement or duration for hyoid maximum elevation (DOHME). There is no penetration or aspiration for both complete denture and implant overdenture oral conditions.

CONCLUSION

Implant retained overdentures have a positive effect on hyoid displacement during swallowing of thin liquid bolus consistency relative to conventional complete dentures.

TRIAL REGISTRATION

Retrospectively registered (NCT06187181) 02/1/2024.

Automatic Tracking of Hyoid Bone Displacement and Rotation Relative to Cervical Vertebrae in Videofluoroscopic Swallow Studies Using Deep Learning

The hyoid bone displacement and rotation are critical kinematic events of the swallowing process in the assessment of videofluoroscopic swallow studies (VFSS). However, the quantitative analysis of such events requires frame-by-frame manual annotation, which is labor-intensive and time-consuming. Our work aims to develop a method of automatically tracking hyoid bone displacement and rotation in VFSS. We proposed a full high-resolution network, a deep learning architecture, to detect the anterior and posterior of the hyoid bone to identify its location and rotation. Meanwhile, the anterior-inferior corners of the C2 and C4 vertebrae were detected simultaneously to automatically establish a new coordinate system and eliminate the effect of posture change. The proposed model was developed by 59,468 VFSS frames collected from 1488 swallowing samples, and it achieved an average landmark localization error of 2.38 pixels (around 0.5% of the image with 448 × 448 pixels) and an average angle prediction error of 0.065 radians in predicting C2-C4 and hyoid bone angles. In addition, the displacement of the hyoid bone center was automatically tracked on a frame-by-frame analysis, achieving an average mean absolute error of 2.22 pixels and 2.78 pixels in the x-axis and y-axis, respectively. The results of this study support the effectiveness and accuracy of the proposed method in detecting hyoid bone displacement and rotation. Our study provided an automatic method of analyzing hyoid bone kinematics during VFSS, which could contribute to early diagnosis and effective disease management.

Timing of True Vocal Cords Closure for Safe Swallowing: A Review of 5 Studies Using 3D Analysis Using Computerized Tomography (CT)

Timely and complete laryngeal closure is critical for a successful swallow. Researchers have studied laryngeal closure, including true vocal cords (TVC) closure, closure of the arytenoids to the epiglottis base (laryngeal vestibule closure), and epiglottic inversion, but the most commonly available imaging tools have limitations that do not allow the study of these components individually. Swallowing computerized tomography (CT) has enabled three-dimensional dynamic visualization and quantitative evaluation of swallowing events providing a unique view of swallowing-related structures and their motion. Using CT, TVC closure can be visualized and evaluated on any plane or cross-section without being obscured by of laryngeal vestibule closure or epiglottis inversion. The current review summarizes the results of five papers evaluating the effects of bolus consistency and volume, posture, and age on TVC closure. The combined results of these studies suggest that TVC closure is responsive to oral sensory input based on bolus consistency and size and can be modulated in response to conditions perceived to increase the risk of airway invasion. These results are meaningful for dysphagia rehabilitation as it suggests that interventions to improve TVC closure are likely to enhance airway protection.

Temporal Characteristics of Penetration and Aspiration in Patients with Severe Dysphagia Associated with Lateral Medullary Syndrome

To assess the severity and timing of penetration and aspiration (PA) of severe dysphagia after lateral medullary syndrome (LMS) and its association with temporal characteristics. We performed videofluoroscopic swallowing studies (VFSS) in 48 patients with LMS and severe dysphagia and 26 sex- and age-matched healthy subjects. The following temporal measures were compared between groups: velopharyngeal closure duration (VCD); hyoid bone movement duration (HMD); laryngeal vestibular closure duration (LCD); upper esophageal sphincter (UES) opening duration (UOD); stage transition duration (STD) and the interval between laryngeal vestibular closure and UES opening (LC-UESop). The association between temporal measures and Penetration-Aspiration Scale (PAS) scores was analyzed. Differences in timing measures were compared between subgroups (safe swallows, and swallows with PA events during and after the swallow). PAS scores ≥ 3 were seen in 48% of swallows (4% occuring before, 35% occurred during and 61% after the swallow) from the LMS patients. Significantly longer STD and LC-UESop were found in the patients compared to the healthy subjects (p < 0.05). Significant negative correlations with PA severity were found for HMD, LCD, and UOD. Short UOD was the strongest predictor with an area under the receiver-operating-characteristic curve of 0.66. UOD was also significantly shorter in cases of PA after the swallow (p < 0.01). Patients with LMS involving severe dysphagia exhibit a high frequency of PA (mostly during and after swallowing). PA events were associated with shorter UOD, HMD, and LCD. Notably, shortened UOD appears to be strongly associated with PA.

A Large Cohort Analysis of Epiglottic Phenotypes and Pharyngeal Residue

OBJECTIVE

To describe the phenotypic characteristics of the epiglottis at rest and their impact on vallecular residue.

METHODS

Videofluoroscopic studies (VFSS) were pooled from 2 Laryngology practices, and Image J was used to measure epiglottic anatomic features at rest. Studies were rated by the MBSImp and presence of vallecular residue following swallow of thin and puree boluses. A conditional inference tree analysis was performed to isolate which epiglottic parameters were risk factors for presence of vallecular reside followed by logistic regression.

RESULTS

The majority of patients had a normal shaped epiglottis, followed by omega shape. The mean angle of the epiglottis from the hyoid was approximately 90°. Only abnormal epiglottic movement was associated with increased risk of residue for thin boluses (OR 35.09, CI 10.93-158.66, P < .001). However, in those with normal epiglottic movement, age >70 years old was associated with increased risk of residue (OR 3.98, CI 1.73-9.23, P = .001). For puree boluses, a normal or omega shaped epiglottis was associated with residue (OR 5.19, CI 2.41-11.51, P < .001), and this relationship was further modulated by increased distance of the epiglottic tip from the posterior pharyngeal wall. No other anatomic features of the resting epiglottis were associated with residue. Comorbidities potentially affecting swallow were infrequent in the cohort and were not associated with residue.

CONCLUSION

Abnormal epiglottic movement is associated with aspiration, and in this study we find that abnormal epiglottic movement increases the risk of vallecular residue and that older age is a risk factor for residue. The resting properties of the epiglottis do not appear to be associated with abnormal epiglottic movement or residue.

The effect of liquid consistency on penetration-aspiration: a Bayesian analysis of two large datasets

Introduction

Thickened liquids are commonly recommended to reduce the risk of penetration-aspiration. However, questions persist regarding the impact of bolus consistency on swallowing safety. The common practice of summarizing Penetration-Aspiration Scale (PAS) scores based on worst scores is a bias in prior analyses. The aim of this study was to examine the impact of liquid consistency on PAS scores using a Bayesian multilevel ordinal regression model approach, considering all scores across repeated bolus trials. A second aim was to determine whether PAS scores differed across thickener type within consistency.

Methods

We analyzed two prior datasets (D1; D2). D1 involved 678 adults with suspected dysphagia (289 female; mean age 69 years, range 20-100). D2 involved 177 adults (94 female; mean age 54 years, range 21-85), of whom 106 were nominally healthy and 71 had suspected dysphagia. All participants underwent videofluoroscopy involving ≥3 boluses of 20% w/v thin liquid barium and of xanthan-gum thickened barium in mildly, moderately and extremely thick consistencies. D2 participants also swallowed trials of slightly thick liquid barium, and starch-thickened stimuli for each thickened consistency. Duplicate blinded rating yielded PAS scores per bolus, with discrepancies resolved by consensus. PAS ratings for a total of 8,185 and 3,407 boluses were available from D1 and D2, respectively. Bayesian models examined PAS patterns across consistencies. We defined meaningful differences as non-overlapping 95% credible intervals (CIs).

Results

Across D1 and D2, penetration occurred on 10.87% of trials compared to sensate (0.68%) and silent aspiration (1.54%), with higher rates of penetration (13.47%) and aspiration (3.07%) on thin liquids. For D1, the probability of a PAS score > 2 was higher for thin liquids with weighted PAS scores of 1.57 (CI: 1.48, 1.66) versus mildly (1.26; CI: 1.2, 1.33), moderately (1.1; CI: 1.07, 1.13), and extremely thick liquids (1.04; CI: 1.02, 1.08). D2 results were similar. Weighted PAS scores did not meaningfully differ between thin and slightly thick liquids, or between starch and xanthan gum thickened liquids.

Discussion

These results confirm that the probability of penetration-aspiration is greatest on thin liquids compared to thick liquids, with significant reductions in PAS severity emerging with mildly thick liquids.

Dysphagia Pattern in Early to Moderate Parkinson's Disease Caused by Abnormal Pharyngeal Kinematic Function

Airway invasion is common in patients with Parkinson's disease (PD) and can cause serious complications. However, a PD-related dysphagic pattern has not been clearly elucidated. In this study, 53 patients with early to moderate PD were enrolled to undergo a videofluoroscopic study of swallowing evaluation (VFSS) and a battery of neuropsychological assessments. A set of VFSS variables (three visuoperceptual, nine temporal, and six spatial) were measured. The main effects of bolus viscosity and volume on airway invasion were calculated. Statistical analyses were performed to determine key kinematic factors of airway invasion for swallowing each bolus type. Airway invasion frequency was significantly higher for liquid boluses (liquid vs. pudding P < 0.001; liquid vs. honey P = 0.006). Laryngeal vestibule closure reaction time (LVCrt) was the key kinematic factor of airway invasion for 3 ml liquid swallow (P = 0.040), anterior displacement of hyoid bone was the key kinematic factor for both 5 ml and 10 ml liquid swallows (P = 0.010, 0.034, respectively). Male sex and advanced Hoehn and Yahr stage were significantly related to reduced anterior displacement of hyoid bone. These results reveal the dysphagic pattern related to PD, demonstrating that prolonged LVCrt and reduced anterior displacement of hyoid bone are two crucial kinematic factors contributing to airway invasion during the liquid swallow. In addition, hyoid bone dysfunction was correlated with disease severity and male sex. Our findings warrant further investigation of the pathophysiological mechanism of dysphagia in PD and would guide clinical intervention.

Impacts of Deep Brain Stimulation of the Globus Pallidus Internus on Swallowing: A Retrospective, Cross-Sectional Study

Deep brain stimulation (DBS) is a common treatment for motor symptoms of Parkinson disease (PD), a condition associated with increased risk of dysphagia. The effect of DBS on swallowing function has not been comprehensively evaluated using gold-standard imaging techniques, particularly for globus pallidus internus (GPi) DBS. The objective of this retrospective, cross-sectional study was to identify differences in swallowing safety and timing kinematics among PD subjects with and without GPi DBS. We investigated the effects of unilateral and bilateral GPi DBS as well as the relationship between swallowing safety and DBS stimulation parameters, using retrospective analysis of videofluoroscopy recordings (71 recordings from 36 subjects) from electronic medical records. Outcomes were analyzed by surgical status (pre-surgical, unilateral DBS, bilateral DBS). The primary outcome was percent of thin-liquid bolus trials rated as unsafe, with Penetration-Aspiration Scale scores of 3 or higher. Secondary analyses included swallowing timing measures, relationships between swallowing safety and DBS stimulation parameters, and Dynamic Imaging Grade of Swallowing Toxicity ratings. Most subjects swallowed all boluses safely (19/29 in the pre-surgical, 16/26 in the unilateral DBS, and 10/16 in the bilateral DBS conditions). Swallowing safety impairment did not differ among stimulation groups. There was no main effect of stimulation condition on timing metrics, though main effects were found for sex and bolus type. Stimulation parameters were not correlated with swallowing safety. Swallowing efficiency and overall impairment did not differ among conditions. These results provide evidence that GPi DBS does not affect pharyngeal swallowing function. Further, prospective, investigations are needed.

Quantitative Analysis of Temporal Parameters Correlated with Aspiration and Lesion Location in Stroke Patients

The purpose of this study was to identify differences in temporal parameters correlating to the presence of aspiration and the severity of penetration-aspiration scale (PAS) in patients with dysphagia after stroke. We also investigated whether there was a significant difference in temporal parameters based on the location of the stroke lesion. A total of 91 patient videofluoroscopic swallowing study (VFSS) videos of stroke patients with dysphagia were retrospectively analyzed. Various temporal parameters including oral phase duration, pharyngeal delay time, pharyngeal response time, pharyngeal transit time, laryngeal vestibule closure reaction time, laryngeal vestibule closure duration, upper esophageal sphincter opening duration and upper esophageal sphincter reaction time were measured. Subjects were grouped by the presence of aspiration, PAS score, and location of the stroke lesion. Pharyngeal response time, laryngeal vestibule closure duration, and upper esophageal sphincter opening duration were significantly prolonged in the aspiration group. These three factors showed positive correlation with PAS. In terms of stroke lesion, oral phase duration was significantly prolonged in the supratentorial lesion group, while upper esophageal sphincter opening duration was significantly prolonged in the infratentorial lesion group. We have demonstrated that quantitative temporal analysis of VFSS can be a clinically valuable tool identifying dysphagia pattern associated with stroke lesion or aspiration risk.

Videofluoroscopic Measures of Swallowing After Partial Epiglottidectomy for Dysphagia

OBJECTIVE

Partial epiglottidectomy has a role in improving dysphagia due to epiglottic obstruction. This study evaluates objective parameters of swallow function in patients who underwent partial epiglottidectomy.

STUDY DESIGN

Retrospective study design.

SETTING

Tertiary Care University Academic Medical Center.

METHODS

A review was performed of patients who underwent CO2 laser partial epiglottidectomy for the treatment of dysphagia at a single tertiary care academic center over a 4-year period. Objective swallowing parameters were evaluated from pre- and postoperative modified barium swallow studies using SwallowTail Advanced Measurement software using blinded reviewers. The postswallow pharyngeal residue (bolus clearance ratio or BCR), spatiotemporal swallowing variables (oropharyngeal [OPT], hypopharyngeal [HPT], and total pharyngeal transit times [TPT]), and airway protection (Penetration-Aspiration Scale [PAS]) were analyzed. Student paired t test was used to determine significant changes in outcome parameters pre- and postsurgery.

RESULTS

Forty-three patients (age range 45-92 years, median 70) met the inclusion criteria. A majority (69.8%) had a history of external beam radiation therapy for head and neck cancer. BCR decreased significantly from a mean of 31.7% presurgery to 24.2% (p = .01) postsurgery. OPT, HPT, and TPT did not differ significantly postsurgery. The mean Eating Assessment Tool-10 score improved from 25.1 to 20.2 after treatment (p = .03). PAS score improved by 15.4% and remained stable at 66.2% after surgery.

CONCLUSION

Partial epiglottidectomy improves pharyngeal bolus clearance in properly selected patients with dysphagia due to epiglottic obstruction. Patients demonstrated stable swallow function with the benefit of reduced postswallow residue following surgical intervention.

Quantitative approach to analyze hyoid bone movement during swallowing by ultrasound: an integrative review

PURPOSE

To synthesize the scientific knowledge on which measurements of hyoid bone movement during swallowing are obtained by ultrasonography and how to extract these measures.

RESEARCH STRATEGIES

The PECO question and combinations of descriptors and keywords were formulated in the electronic databases Medline/PubMed, EMBASE, Web of Science, Scopus and Lilacs.

SELECTION CRITERIA

Articles that used ultrasonography to analyze measurements of hyoid bone movement during swallowing were included, regardless of language, year of publication, or presence of deglutition disorders.

DATA ANALYSIS

The included articles were analyzed for: year, study site, study design, population, sample size, equipment used, transducer positioning, measurements obtained, method of extraction, and reliability of measurements.

RESULTS

Twenty-six articles met the eligibility criteria. The most frequent measurement was hyoid movement maximum amplitude, followed by time and velocity. There was great variability in the study population, equipment used, positioning of the transducer and method of extraction of the measurements. Thus, it was not possible to find a standard model to extract the measures. The level of reliability was investigated in only eight articles.

CONCLUSION

Amplitude, time and velocity are the measures of hyoid bone movement during swallowing that can be obtained by ultrasonography. There is no standardization on how to extract these measurements.

Functional Lingual Pressure Thresholds for Swallowing Safety and Efficiency Impairments in Amyotrophic Lateral Sclerosis

Although reductions in lingual strength are reported in individuals with amyotrophic lateral sclerosis (ALS) that are associated with dysphagia; determination of a functional lingual pressure threshold (FLPT) has not yet been established. The present study therefore sought to identify an FLPT for impaired swallowing safety and efficiency in individuals with ALS.Thirty individuals with ALS completed a standardized videofluoroscopic swallowing examination and maximum anterior isometric lingual pressure testing using the Iowa Oral Performance Instrument. Duplicate, blinded ratings of the validated Penetration-Aspiration Scale (PAS) scores and Analysis of Swallowing Physiology: Events, Kinematics and Timing (ASPEKT) were performed. Binary classifications of safety (unsafe: PAS: ≥ 3) and efficiency (inefficient: ≥ 3% worst total pharyngeal residue) were derived. Descriptives and receiver operating characteristic curve analyses (AUC, sensitivity, specificity) were performed.Unsafe and inefficient swallowing were instrumentally confirmed in 57% and 70% of ALS patients, respectively. Across the entire cohort, the mean maximum lingual physiologic capacity was 32.1 kilopascals ('kPa'; SD: 18.1 kPa). The identified FLPT for radiographically confirmed unsafe swallowing was 43 kPa (sensitivity: 94%, specificity: 62%, AUC 0.82, p = 0.003). FLPT for inefficient swallowing was 46 kPa (sensitivity: 86%, specificity: 56%, AUC = 0.77, p = 0.02).These data provide preliminary FLPT data in a small cohort of individuals with ALS that need to be further investigated in larger cohorts to inform clinical screening practices.

Temporal Sequence of Laryngeal Vestibule Closure and Reopening is Associated With Airway Protection

BACKGROUND

Upper esophageal sphincter opening (UESO), and laryngeal vestibule closure (LVC) are two essential kinematic events whose timings are crucial for adequate bolus clearance and airway protection during swallowing. Their temporal characteristics can be quantified through time-consuming analysis of videofluoroscopic swallow studies (VFSS).

OBJECTIVES

We sought to establish a model to predict the odds of penetration or aspiration during swallowing based on 15 temporal factors of UES and laryngeal vestibule kinematics.

METHODS

Manual temporal measurements and ratings of penetration and aspiration were conducted on a videofluoroscopic dataset of 408 swallows from 99 patients. A generalized estimating equation model was deployed to analyze association between individual factors and the risk of penetration or aspiration.

RESULTS

The results indicated that the latencies of laryngeal vestibular events and the time lapse between UESO onset and LVC were highly related to penetration or aspiration. The predictive model incorporating patient demographics and bolus presentation showed that delayed LVC by 0.1 s or delayed LVO by 1% of the swallow duration (average 0.018 s) was associated with a 17.19% and 2.68% increase in odds of airway invasion, respectively.

CONCLUSION

This predictive model provides insight into kinematic factors that underscore the interaction between the intricate timing of laryngeal kinematics and airway protection. Recent investigation in automatic noninvasive or videofluoroscopic detection of laryngeal kinematics would provide clinicians access to objective measurements not commonly quantified in VFSS. Consequently, the temporal and sequential understanding of these kinematics may interpret such measurements to an estimation of the risk of aspiration or penetration which would give rise to rapid computer-assisted dysphagia diagnosis.

LEVEL OF EVIDENCE

2 Laryngoscope, 133:521-527, 2023.

Non-Invasive Sensor-Based Estimation of Anterior-Posterior Upper Esophageal Sphincter Opening Maximal Distension

OBJECTIVE

Dysphagia management relies on the evaluation of the temporospatial kinematic events of swallowing performed in videofluoroscopy (VF) by trained clinicians. The upper esophageal sphincter (UES) opening distension represents one of the important kinematic events that contribute to healthy swallowing. Insufficient distension of UES opening can lead to an accumulation of pharyngeal residue and subsequent aspiration which in turn can lead to adverse outcomes such as pneumonia. VF is usually used for the temporal and spatial evaluation of the UES opening; however, VF is not available in all clinical settings and may be inappropriate or undesirable for some patients. High resolution cervical auscultation (HRCA) is a noninvasive technology that uses neck-attached sensors and machine learning to characterize swallowing physiology by analyzing the swallow-induced vibrations/sounds in the anterior neck region. We investigated the ability of HRCA to noninvasively estimate the maximal distension of anterior-posterior (A-P) UES opening as accurately as the measurements performed by human judges from VF images.

METHODS AND PROCEDURES

Trained judges performed the kinematic measurement of UES opening duration and A-P UES opening maximal distension on 434 swallows collected from 133 patients. We used a hybrid convolutional recurrent neural network supported by attention mechanisms which takes HRCA raw signals as input and estimates the value of the A-P UES opening maximal distension as output.

RESULTS

The proposed network estimated the A-P UES opening maximal distension with an absolute percentage error of 30% or less for more than 64.14% of the swallows in the dataset.

CONCLUSION

This study provides substantial evidence for the feasibility of using HRCA to estimate one of the key spatial kinematic measurements used for dysphagia characterization and management. Clinical and Translational Impact Statement: The findings in this study have a direct impact on dysphagia diagnosis and management through providing a non-invasive and cheap way to estimate one of the most important swallowing kinematics, the UES opening distension, that contributes to safe swallowing. This study, along with other studies that utilize HRCA for swallowing kinematic analysis, paves the way for developing a widely available and easy-to-use tool for dysphagia diagnosis and management.

Qualifications, professional roles and service practices of nurses, occupational therapists and speech-language pathologists in the management of adults with oropharyngeal dysphagia: a Nordic survey

PURPOSE

To identify the qualifications, professional roles and service practices of nurses, occupational therapists (OTs) and speech-language pathologists (SLPs) in the management of adults with oropharyngeal dysphagia (OD) in the Nordic countries.

METHODS

A web-based survey was developed that consisted of 50 questions on respondent demographics, education, experience, roles and service practices provided for adults with OD. The survey was distributed to practicing nurses, OTs, and SLPs in five Nordic countries via professional associations, social media, online networks and snowballing.

RESULTS

Data from 396 nurses, OTs and SLPs whom provided services for adults with OD revealed that the majority of respondents worked in acute care and inpatient rehabilitation facilities. Most respondents had minimal undergraduate education and practical clinical training in OD. Notable variances in roles and service practices in OD between professions and countries were found. OTs were the primary service provider for OD management in Denmark, while SLPs had this role in the other Nordic countries. Nurses were mainly involved in screening and some compensatory treatments in most Nordic countries. Limited use of evidence-based screening, non-instrumental or instrumental clinical assessments and rehabilitative therapeutic methods was evident.

CONCLUSIONS

Study results highlight challenges in education and training of professionals responsible for the management of adults with OD in the Nordic countries. Increased use of evidence-based assessment and exercise-based treatments to improve swallowing are warranted. Adherence to European and international clinical practice guidelines for the management of adults with OD is recommended.

Deep Learning for Automatic Hyoid Tracking in Videofluoroscopic Swallow Studies

The hyoid bone excursion is one of the most important gauges of larynx elevation in swallowing, contributing to airway protection and bolus passage into the esophagus. However, the implications of various parameters of hyoid bone excursion, such as the horizontal or vertical displacement and velocity, remain elusive and raise the need for a tool providing automatic kinematics analysis. Several conventional and deep learning-based models have been applied automatically to track the hyoid bone, but previous methods either require partial manual localization or do not transform the trajectory by anatomic axis. This work describes a convolutional neural network-based algorithm featuring fully automatic hyoid bone localization and tracking and spine axis determination. The algorithm automatically estimates the hyoid bone trajectory and calculates several physical quantities, including the average velocity and displacement in horizontal or vertical anatomic axis. The model was trained in a dataset of 365 videos of videofluoroscopic swallowing from 189 patients in a tertiary medical center and tested using 44 videos from 44 patients with different dysphagia etiologies. The algorithm showed high detection rates for the hyoid bone. The results showed excellent inter-rater reliability for hyoid bone detection, good-to-excellent inter-rater reliability for calculating the maximal displacement and the average velocity of the hyoid bone in horizontal or vertical directions, and moderate-to-good reliability in calculating the average velocity in horizontal direction. The proposed algorithm allows for complete automatic kinematic analysis of hyoid bone excursion, providing a versatile tool with high potential for clinical applications.

Dysphagia Presentation, Airway Invasion, and Gender Differences in a Clinically Based Sample of People with Parkinson's Disease

Dysphagia in People with Parkinson's Disease (PWPD) is expected to occur in most individuals. The manifestation of dysphagia and its salient swallow dysfunction characteristics leading to decreased airway safety are not well understood. The aim of this study was to quantify dysphagia presentation and severity, examine contributors to airway invasion, and explore gender differences in dysphagia manifestation in PWPD. 60 PWPD in clinical, healthcare settings underwent a Videofluoroscopic Swallow Study (VFSS) after referral for complaints of dysphagia. VFSS records and videos were analyzed to obtain dysphagia diagnosis, Videofluoroscopic Dysphagia Scale (VDS) scores, laryngeal vestibule kinematic timings, and Penetration-Aspiration Scale scores. Frequencies of VDS component and PAS scores were examined. MANOVA and logistic regression analyses were used to identify predictors of penetration and aspiration. Pharyngeal stage dysphagia was prevalent throughout PWPD and presented more frequently than oral stage dysphagia. Pharyngeal residue was a significant predictor for aspiration events. Laryngeal vestibule closure reaction time (LVCrt) and duration time (LVCd) were significant predictors of airway invasion, as were bolus consistency and volume. LVCrt, LVCd, and pharyngeal stage VDS scores were significantly altered in men compared to women in PWPD. A broad clinical sample of PWPD displayed atypical frequencies of airway invasion and frequent atypical scores of oral and pharyngeal stage physiologies. Thicker and smaller bolus consistencies significantly reduced the odds of airway invasion. Men and women presented with significantly different swallow physiology including prolonged LVCrt, LVCd, and more frequent atypical scores of pharyngeal residue and laryngeal elevation.Journal instruction requires a country for affiliations; however, these are missing in affiliation [1, 2]. Please verify if the provided country are correct and amend if necessary.Yes, USA is correct as the provided country.

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.

Increased cortical-medulla functional connectivity is correlated with swallowing in dysphagia patients with subacute infratentorial stroke

Patients with infratentorial stroke (IS) exhibit more severe dysphagia and a higher risk of aspiration than patients with supratentorial stroke. Nevertheless, a large proportion of patients with IS regain swallowing function within 6 months; however, the neural mechanism for this recovery remains unclear. We aimed to investigate possible neuroplastic changes involved using functional magnetic resonance imaging (fMRI) and their relation to swallowing function. We assessed 21 patients with IS (mean age: 59.9 ± 11.1 years) exhibiting dysphagia in the subacute phase and 21 healthy controls (mean age: 57.1 ± 7.8 years). Patient evaluations were based on the functional oral intake scale (FOIS), videofluoroscopic swallow study (VFSS), and fMRI. Temporal swallowing measures and the penetration-aspiration scale (PAS) were obtained using VFSS. Whole-brain-medulla resting-state functional connectivity (rsFC) was calculated and compared between patients and healthy controls. The rsFCs were also correlated with functional measures within the patient group. In patients with IS, whole-brain-medulla rsFCs were significantly higher in the precuneus, the left and right precentral gyrus, and the right supplementary motor area compared to those in healthy controls (P < 0.001, family-wise error-corrected cluster-level P < 0.05). The rsFCs to the medulla for the left (r = -0.507, P = 0.027) and right side (r = -0.503, P = 0.028) precentral gyrus were negatively correlated with the PAS. The rsFC between the left (r = 0.470, P = 0.042) and right (r = 0.459, P = 0.048) precentral gyrus to the medulla was positively correlated with upper esophageal sphincter opening durations (UOD). In addition, PAS was also correlated with UOD (r = -0.638, P = 0.003) whereas the laryngeal closure duration was correlated with the hyoid bone movement duration (r = 0.550, P = 0.015). Patients with IS exhibited overall modulation of cortical-medulla connectivity during the subacute phase. Patients with higher connectivities showed better swallowing performance. These findings support that there is cortical involvement in swallowing regulation after IS and can aid in determining potential treatment targets for dysphagia.

Automated assessment of hyoid movement during normal swallow using ultrasound

BACKGROUND

The potential for using ultrasound by speech and language therapists (SLTs) as an adjunct clinical tool to assess swallowing function has received increased attention during the COVID-19 pandemic, with a recent review highlighting the need for further research on normative data, objective measurement, elicitation protocol and training. The dynamic movement of the hyoid, visible in ultrasound, is crucial in facilitating bolus transition and protection of the airway during a swallow and has shown promise as a biomarker of swallowing function.

AIMS

To examine the kinematics of the hyoid during a swallow using ultrasound imaging and to relate the patterns to the different stages of a normal swallow. To evaluate the accuracy and robustness of two different automatic hyoid tracking methods relative to manual hyoid position estimation.

METHODS & PROCEDURES

Ultrasound data recorded from 15 healthy participants swallowing a 10 ml water bolus delivered by cup or spoon were analysed. The movement of the hyoid was tracked using manually marked frame-to-frame positions, automated hyoid shadow tracking and deep neural net (DNN) tracking. Hyoid displacement along the horizontal image axis (HxD) was charted throughout a swallow, and the maximum horizontal displacement (HxD max) and maximum hyoid velocity (HxV max) along the same axis were automatically calculated.

OUTCOMES & RESULTS

The HxD and HxV of 10 ml swallows are similar to values reported in the literature. The trajectory of the hyoid movement and its location at significant swallow event time points showed increased hyoid displacement towards the peak of the swallow. Using an interclass correlation coefficient, HxD max and HxV max values derived from the DNN tracker and shadow tracker are shown to be in high agreement and moderate agreement, respectively, when compared with values derived from manual tracking.

CONCLUSIONS & IMPLICATIONS

The similarity of the hyoid tracking results using ultrasound to previous reports based on different instrumental tools supports the possibility of using hyoid movement as a measure of swallowing function in ultrasound. The use of machine learning to automatically track the hyoid movement potentially provides a reliable and efficient way to quantify swallowing function. These findings contribute towards improving the clinical utility of ultrasound as a swallowing assessment tool. Further research on both normative and clinical populations is needed to validate hyoid movement metrics as a means of differentiating normal and abnormal swallows and to verify the reliability of automatic tracking.

WHAT THIS PAPER ADDS

What is already known on this subject There is growing interest in the use of ultrasound as an adjunct tool for assessing swallowing function. However, there is currently insufficient knowledge about the patterning and timing of lingual and hyoid movement in a typical swallow. We know that movement of the hyoid plays an essential role in bolus transition and airway protection. However, manual tracking of hyoid movement is time-consuming and restricts the extent of large-scale normative studies. What this study adds We show that hyoid movement can be tracked automatically, providing measurable continuous positional data. Measurements derived from this objective data are comparable with similar measures previously reported using videofluoroscopy and of the two automatic trackers assessed, the DNN approach demonstrates better robustness and higher agreement with manually derived measures. Using this kinematic data, hyoid movement can be related to different stages of swallowing. Clinical implications of this study This study contributes towards our understanding of the kinematics of a typical swallow by evaluating an automated hyoid tracking method, paving the way for future studies of typical and disordered swallow. The challenges of image acquisition highlight issues to be considered when establishing clinical protocols. The application of machine learning enhances the utility of ultrasound swallowing assessment by reducing the labour required and permitting a wider range of hyoid measurements. Further research in normative and clinical populations is facilitated by automatic data extraction allowing the validity of prospective hyoid measures in differentiating different types of swallows to be rigorously assessed.

Scoring the Penetration-Aspiration Scale (PAS) in Two Conditions: A Reliability Study

A widely applied metric for identifying airway invasion events is the Penetration-Aspiration Scale (PAS). PAS scores are often included as primary outcome measures in clinical interventional studies, applied to characterize airway protection in a particular disease, used to establish a normal referent for control group comparisons without dysphagia, and as determinants or predictors of clinical outcomes. Despite the widespread use of the PAS, there is variability in scoring condition. One common method used in research studies includes rater scores applied to each single swallow that occurred during a modified barium swallow study (MBSS) of the same patient. A second common method includes raters scoring single swallow segments that have been spliced from full MBSS from different patients. These single swallow segments are then randomly distributed and the rater is blinded to all swallows that occurred during that patient MBSS. The potential effects of different scoring conditions on rater reliability and score accuracy have not been studied and may have high relevance for the conclusion drawn from the result. The primary aim of this investigation is to determine the impact of two scoring conditions on rater reliability and score accuracy: 1. Contextual, unblinded scoring condition and 2. Randomized, blinded condition. Results of the present study show that no statistically significant differences in PAS rater reliability and score accuracy were found between the two scoring conditions. If findings from this pilot study are reproduced in larger sample sizes, the time and intensity involved in splicing and randomizing MBSS for scoring may not be necessary.

Reliability of the Penetration-Aspiration Scale and Temporal and Clearance Measures in Poststroke Dysphagia: Videofluoroscopic Analysis From the Swallowing Treatment using Electrical Pharyngeal Stimulation Trial

PURPOSE

Information on reliability of outcome measures used to assess the effectiveness of interventions in dysphagia rehabilitation is lacking, particularly when used by different research groups. Here, we report on reliability of the penetration-aspiration scale (PAS) and temporal and clearance measures, determined using videofluoroscopy.

METHOD

Secondary analysis used videofluoroscopies from the Swallowing Treatment using Electrical Pharyngeal Stimulation trial in subacute stroke. PAS scores (719 scores from 18 participants) were evaluated and compared to the original PAS scores from the trial. Five conditions were assessed, including reliability for every swallow and overall mean of the worst PAS score. Operational rules for assessing temporal and clearance measures were also developed using the same data, and reliability of these rules was assessed. Reliability of component-level and derivative-level scores was assessed using the intraclass correlation coefficient (ICC) and weighted kappa.

RESULTS

Image quality was variable. Interrater reliability for the overall mean of the worst PAS score was excellent (ICC = .914, 95% confidence interval [CI] [.853, .951]) but moderate for every swallow in the bolus (ICC = .743, 95% CI [.708, .775]). Intrarater reliability for PAS was excellent (all conditions). Excellent reliability (both inter- and intrarater > .90) was seen for temporal measures of stage transition duration (ICC = .998, 95% CI [.993, .999] and ICC = .995, 95% CI [.987, .998], respectively) as well as initiation of laryngeal closure and pharyngeal transit time and all individual swallow events. Strong scores were obtained for some clearance measures; others were moderate or weak.

CONCLUSIONS

Interrater reliability for PAS is acceptable but depends on how the PAS scores are handled in the analysis. Interrater reliability for most temporal measures was high, although some measures required additional training. No clearance measures had excellent reliability.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19090088.

Determining the Relationship Between Hyoid Bone Kinematics and Airway Protection in Swallowing

PURPOSE

Research remains equivocal regarding the links between hyoid movement and penetration-aspiration. The aims of this study were (a) to explore associations between hyoid parameters, laryngeal vestibule closure (LVC) parameters, and penetration-aspiration on thin liquids; and (b) to determine which of these parameters are the strongest predictors of penetration-aspiration.

METHOD

This study involved retrospective analysis of an existing videofluoroscopy data set, collected in 305 participants (152 males) with noncongenital/nonsurgical/non-oncological risk for dysphagia. We extracted data for six thin liquid swallows per participant, and obtained measures of hyoid movement (peak position, speed) and LVC (complete/incomplete, timing, duration). Resulting values were coded as typical/atypical relative to healthy reference data. Relationships were explored using chi-square tests and odds ratios (a) for the entire data set and (b) for the subset of data with complete LVC. Hierarchical logistic regression models determined the strongest predictors of penetration-aspiration.

RESULTS

Significant associations were found between penetration-aspiration and incomplete LVC, prolonged time-to-most-complete-LVC, short LVC duration, reduced anterior hyoid peak position, and reduced hyoid speed. Hyoid measures were also significantly associated with LVC parameters. In the first regression model, incomplete LVC and prolonged time-to-most-complete-LVC were the only significant predictors of penetration-aspiration. For cases with complete LVC, the only significant predictor was prolonged time-to-most-complete-LVC.

CONCLUSIONS

Although reduced anterior hyoid peak position and speed are associated with penetration-aspiration on thin liquids, these measures do not independently account for penetration-aspiration when considered in conjunction with measures of LVC. When identifying mechanisms explaining penetration-aspiration, clinicians should focus on LVC (complete/incomplete) and timeliness of LVC.

Swallowing kinematic analysis might be helpful in predicting aspiration and pyriform sinus stasis

Aspiration due to dysphagia can lead to aspiration, which negatively impacts a patient’s overall prognosis. Clinically, videofluoroscopic swallow study (VFSS) is considered the gold-standard instrument to determine physiological impairments of swallowing. According to previously published literature, kinematic analyses of VFSS might provide further information regarding aspiration detection. In this study, 449 files of VFSS studies from 232 patients were divided into three groups: normal, aspiration, and pyriform sinus stasis. Kinematic analyses and between-group comparison were conducted. Significant between-group differences were noted among parameters of anterior hyoid displacement, maximal hyoid displacement, and average velocity of hyoid movement. No significant difference was detected in superior hyoid displacement. Furthermore, receiver-operating characteristic (ROC) analyses of anterior hyoid displacement, velocity of anterior hyoid displacement, and average velocity of maximal hyoid displacement showed acceptable predictability for detecting aspiration. Using 33.0 mm/s as a cutoff value of average velocity of maximal hyoid displacement, the sensitivity of detecting the presence of aspiration was near 90%. The investigators therefore propose that the average velocity of maximal hyoid displacement may serve as a potential screening tool to detect aspiration.

The effect of the Shaker head‐lift exercise on swallowing function following treatment for head and neck cancer: Results from a randomized, controlled trial with videofluoroscopic evaluation

Background

Dysphagia is common following treatment for head and neck cancer (HNC) and intervention to improve swallowing function is warranted. This study aimed to evaluate the efficacy of the Shaker head‐lift exercise (HLE) to improve dysphagia in HNC patients.

Methods

Patients treated for HNC with radiochemotherapy and with subsequent dysphagia were randomly assigned to intervention (HLE, n = 25) and control (standard dysphagia management, n = 27) groups. Videofluoroscopic evaluation of penetration‐aspiration, initiation, residue, movement of selected structures, and self‐perceived swallowing function, before and after 8 weeks of treatment, were compared.

Results

Although adherence to training was high, no statistically significant differences in objectively measured swallowing function between the groups or within‐group changes were found. Self‐perceived swallowing function improved in the intervention group.

Conclusions

In this HNC population, neither HLE nor standard dysphagia management improved objectively measured swallowing function as evaluated after 8 weeks. Future research focusing on finding effective interventions for dysphagia is warranted.

Oral support for patients with severe motor and intellectual disabilities

BACKGROUND

Oral support during feeding was clinically provided to patients with severe motor and intellectual disabilities (SMID) for the prevention of dysphasia. The present study investigated the advantages of oral support anatomically and functionally.

METHODS

A videofluoroscopic swallowing study was conducted on nine patients with SMID (age = 5-41 years; mean age = 15.0; four males, five females) and 24 healthy adults (age = 26-67 years; mean age = 44.3; 16 males, eight females). The movements of the hyoid bone and mandible during pharyngeal swallowing were tracked, and the pharyngeal residues were evaluated. The temporal and spatial features of the movements were compared between patients with and without oral support as well as healthy adults.

RESULTS

The mandible moved downward earlier and showed larger displacement in the patients with SMID. The patients also had insufficient anterior displacement of the hyoid, which was associated with the pharyngeal residue. This displacement was enhanced, and the pharyngeal residue decreased with oral support.

CONCLUSIONS

Oral support to hold the mandible successfully improved hyoid excursion and reduced pharyngeal residue during swallowing, which is a simple and reliable strategy for the prevention of dysphasia in patients with SMID.

Interrater reliability in the temporal quantitative analysis of oropharyngeal swallowing using a specific software

PURPOSE

This study aims to analyze inter-judge reliability by measuring a few temporal parameters of swallowing using a specific software.

METHODS

Six databases that include the results of reliability tests performed in prior studies by the present research group were employed. The datasets were obtained using the same measurement method and include data obtained based on puree (level 3) consistency and liquid (level 0) consistency according to the International Dysphagia Diet Standardization Initiative. In this study, the reliabilities corresponding to the total oral transit time (TOTT), initiation of the pharyngeal response time (PRT), and the pharyngeal transit time (PTT) were measured using the same software; the evaluations performed by a single rater for all datasets were used as the benchmark, and evaluations performed by new raters for each dataset were also included. The intra-class correlation coefficient (ICC) with a 95% confidence interval was employed.

RESULTS

A total of 244 videofluoroscopic swallowing study images were analyzed. In all analyses, the ICCs were >0,75 and showed excellent agreement between the senior and junior raters. The TOTT for level 3 showed ICCs from 0.936 to 1.000 and that for level 0 showed ICCs from 0.997 to 1.000. Further, the PRT showed ICCs from 0.916 to 1.000 for level 3 and from 0.978 to 1.000 for level 0. The PTT showed ICCs from 0.848 to 1.000 for level 3 and from 0.984 to 1.000 for level 0.

CONCLUSION

The reliabilities obtained using this specific software for the TOTT, PRT, and PTT showed excellent agreement.

Hyoid bone movement during swallowing and mechanism of pharyngeal residue in patients with profound intellectual and multiple disabilities

OBJECTIVES

Dysphagia is linked to mortality risk among patients with profound intellectual and multiple disabilities (PIMD); the present study therefore aimed to clarify the characteristics of hyoid movements during swallowing and to examine the mechanism of dysphagia in patients with PIMD.

METHODS

A retrospective video fluoroscopic swallowing study was conducted on 43 patients with PIMD (mean age = 25.4; 25 males, 18 females) and 24 healthy adults (mean age = 44.3; 16 males, 8 females). The movements of the hyoid bone and mandible were tracked frame by frame in the video footage, and their range of movements and trajectories were analyzed.

RESULTS

Most patients showed atypical movement trajectories of the hyoid, such as insufficient anterior movement and increased range of mandibular downward movement, compared with normal adults. Moreover, the mechanism of dysphagia was revealed by structural equation modeling, indicating that insufficient anterior movement could lead to pharyngeal residue in the pyriform sinus.

CONCLUSION

The insufficient anterior movement of the hyoid could be caused by weak ventral suprahyoid muscles and atypical head and neck posture characteristic of patients with PIMD. It may be useful to predict pharyngeal residue from the range of hyoid movements and trajectories for the prevention of aspiration.

A Retrospective Analysis of Swallowing Function and Physiology in Patients Living with Dementia

Dysphagia is commonly diagnosed in patients living with dementia, but we lack understanding of changes in swallowing physiology and the resulting relationship to impairments of safety and efficiency. The purpose of this study was to describe the pathophysiology of dysphagia in a retrospective sample of patients living with dementia. Videofluoroscopy data from 106 adults (mean age: 84) diagnosed with dementia were scored by blinded raters. Raters analyzed 412 thin liquid swallows for safety [Penetration-Aspiration Scale (PAS)], efficiency [% of (C2-C4)²], timing [Pharyngeal Transit Time (PTT), Swallow Reaction Time (SRT), Laryngeal Vestibule Closure Reaction Time (LVCrt), Upper Esophageal Sphincter Opening Duration (UESO)], and kinematics (pharyngeal constriction). Impairment thresholds from existing literature were used to characterize swallowing. Chi-square tests and Pearson's correlations were used to determine associations between swallowing physiology and function. Compared to published norms, we identified significant differences in PTT, SRT, LVCrt, UESO, and degree of maximum pharyngeal constriction. Unsafe swallowing (PAS > 2) was seen in 17% of swallows. Clinically significant residue (i.e., % of (C2-C4)² > 0.54 vallecular; > 0.34 pyriforms) was seen in most patients. Chi-square tests revealed significant associations between LVCrt and unsafe swallowing. There was a weak positive association between post-swallow residue in the pyriforms and poor pharyngeal constriction. Detailed analysis of swallowing physiology in this sample provides insight into the pathophysiological mechanisms associated with dysphagia in patients living with dementia. Further work is needed to explore additional bolus consistencies and to identify how physiology changes based on type and severity of dementia diagnosis.

The Role of White Matter in the Neural Control of Swallowing: A Systematic Review

Background: Swallowing disorders (dysphagia) can negatively impact quality of life and health. For clinicians and researchers seeking to improve outcomes for patients with dysphagia, understanding the neural control of swallowing is critical. The role of gray matter in swallowing control has been extensively documented, but knowledge is limited regarding the contributions of white matter. Our aim was to identify, evaluate, and summarize the populations, methods, and results of published articles describing the role of white matter in neural control of swallowing.

Methods: We completed a systematic review with a multi-engine search following PRISMA-P 2015 standards. Two authors screened articles and completed blind full-text review and quality assessments using an adapted U.S. National Institute of Health's Quality Assessment. The senior author resolved any disagreements. Qualitative synthesis of evidence was completed.

Results: The search yielded 105 non-duplicate articles, twenty-two of which met inclusion criteria. Twenty were rated as Good (5/22; 23%) or Fair (15/22; 68%) quality. Stroke was the most represented diagnosis (n = 20; 91%). All studies were observational, and half were retrospective cohort design. The majority of studies (13/22; 59%) quantified white matter damage with lesion-based methods, whereas 7/22 (32%) described intrinsic characteristics of white matter using methods like fractional anisotropy. Fifteen studies (68%) used instrumental methods for swallowing evaluations. White matter areas commonly implicated in swallowing control included the pyramidal tract, internal capsule, corona radiata, superior longitudinal fasciculus, external capsule, and corpus callosum. Additional noteworthy themes included: severity of white matter damage is related to dysphagia severity; bilateral white matter lesions appear particularly disruptive to swallowing; and white matter adaptation can facilitate dysphagia recovery. Gaps in the literature included limited sample size and populations, lack of in-depth evaluations, and issues with research design.

Conclusion: Although traditionally understudied, there is sufficient evidence to conclude that white matter is critical in the neural control of swallowing. The reviewed studies indicated that white matter damage can be directly tied to swallowing deficits, and several white matter structures were implicated across studies. Further well-designed interdisciplinary research is needed to understand white matter's role in neural control of normal swallowing and in dysphagia recovery and rehabilitation.

Respiratory-swallow coordination in a rat model of chemoradiation

BACKGROUND

Chemoradiation treatment (CRT) for head and neck cancer (HNC) is associated with postswallow inhale events that elevate the risk of penetration/aspiration. The purpose of this study was to assess the validity of a rat model for investigating the effect of CRT on respiratory-swallow coordination.

METHODS

Videofluoroscopic swallow study was performed on 10 Sprague-Dawley rats 3 months post-CRT (3 mg/kg Cisplatin, 10 fractions of 4.5 Gy/day radiotherapy to tongue base), and 10 naïve controls. We examined the effect of CRT on swallow apnea duration, diaphragm movement, and bolus kinematics.

RESULTS

CRT rats had a significant increase in postswallow inhale (p = 0.008), which was associated with significantly longer swallow apnea durations, lower diaphragm displacement at swallow onset, and faster pharyngoesophageal bolus speed.

CONCLUSION

The rat CRT model is valid for the study of respiratory-swallow coordination due to the consistency of findings in this study with those reported in clinical CRT studies in HNC.

Pilot Study of Quantitative Methods for Differentiating Pharyngeal Swallowing Mechanics by Dysphagia Etiology

Quantitative analysis of modified barium swallow (MBS) imaging is useful to determine the impact of various disease states on pharyngeal swallowing mechanics. In this retrospective proof of concept study, kinematic analysis and computational analysis of swallowing mechanics (CASM) were used to demonstrate how these methods differentiate swallowing dysfunction by dysphagia etiology. Ten subjects were randomly selected from four cohorts of dysphagic patients including COPD, head and neck cancer (HNC), motor neuron disease, and stroke. Each subject was age- and gender-matched with healthy, non-dysphagic controls. MBS videos of 5 ml thin and 5 ml thick bolus trials from each subject were used. A MATLAB tracker tool was adapted and updated to collect and compile data for each video (n = 160). For kinematic measurements, a MANOVA was performed with post-hoc analyses to determine group differences. For CASM measurements, a morphometric canonical variate analysis with post hoc analysis was performed to determine group differences. Kinematic analyses indicated statistically significant differences between HNC cohort and controls in distance measurements for hyolaryngeal approximation (p = .001), laryngeal elevation (p = 0.0001), pharyngeal shortening (p = 0.0002), and stage transition duration timing (p = 0.002). Timing differences were noted between the stroke cohort and controls for pharyngeal transit time (p = 0.007). Multivariate morphometric canonical variate analysis showed significant differences between etiology groups (p < 0.0001) with eigenvectors indicating differing patterns of swallowing mechanics. This study demonstrated that swallowing mechanics among cohorts of dysphagic patients can be differentiated using kinematics and CASM, providing different but complementary quantitative methods for investigating the impact of various disease states on swallowing function.

Influence of Thermal and Gustatory Stimulus in the Initiation of the Pharyngeal Swallow and Bolus Location Instroke

INTRODUCTION/OBJECTIVE

The aim of this study is to analyze the influence of sour taste and cold temperature in the initiation of the pharyngeal swallow (IPS) and bolus location at pharyngeal swallow onset in individuals after stroke.

METHODS

Cross-sectional prospective study. The study included 52 individuals with unilateral ischemic stroke. Each individual was assessed by videofluoroscopic swallowing study with 5ml of paste bolus offering four different stimuli (natural, cold, sour, and sour-cold). The individuals were divided into two groups according to the offer sequence. Group 1 (G1) - received a randomized sequence of stimuli (24 individuals), and Group 2 (G2) -the stimuli were offered in the following order: natural, cold, sour, and sour-cold(28 individuals). The IPS time and bolus location at pharyngeal swallow onset were analyzed. The bolus location at pharyngeal swallow onset was defined using six different levels.

RESULTS

Individuals in G1 did not show a significant difference in IPS time between stimuli. However, individuals in G2 presented a significantly shorter IPS time with the sour and sour-cold stimuli than with natural or cold stimuli. The bolus location at pharyngeal swallow onset did not show significant difference between stimuli in both groups. On the other hand, in the G2 it was observed higher frequency of swallowing with sour-cold stimulus at level 1 (the bolus head was located in any region between the fauces pillar and the point where the tongue crosses the inferior border of the mandible).

CONCLUSION

The sour and sour-cold stimuli influenced the IPS time when they were offered in a sequential order. Moreover, both the IPS time and bolus location at pharyngeal swallow onset were not influenced by the sour and sour cold-bolus when offered in a random sequence.

The Influence of Airflow Via High-Flow Nasal Cannula on Duration of Laryngeal Vestibule Closure

The purpose of this experimental study was to investigate the influence of airflow via high-flow nasal cannula (HFNC) on the duration of laryngeal vestibule closure (dLVC) and Penetration-Aspiration Scale (PAS) scores. Twenty-nine healthy adults participated in a repeated-measures design. Each participant completed a videofluoroscopic swallow study while receiving airflow via HFNC across a control condition of zero flow and conditions of 10, 20, 30, 40, 50, and 60 L/min. Five raters rated dLVC and PAS scores. Laryngeal vestibule closure was complete on all swallows. Linear regression revealed that the amount of airflow via HFNC significantly influenced dLVC, F(1, 810) = 19.056, p < .001. The mode of airway invasion for each airflow condition was PAS 2, with > 80% frequency compared to other PAS scores. Aspiration (PAS 7 or 8) did not occur. A Fisher's Exact test determined there was no association between normal/abnormal PAS score and no airflow/HFNC (p = .610). Findings indicate that for healthy adults, airflow via HFNC influenced dLVC in a dose-dependent manner with no change in airway invasion. The influence of HFNC on dLVC was a positive relationship, meaning when airflow increased, dLVC increased, and when airflow decreased, dLVC decreased. Modulation of dLVC in response to the amount of airflow highlights the ability of healthy adults to adapt to swallow conditions as needed to protect the airway.

How Closely do Machine Ratings of Duration of UES Opening During Videofluoroscopy Approximate Clinician Ratings Using Temporal Kinematic Analyses and the MBSImP?

Clinicians evaluate swallow kinematic events by analyzing videofluoroscopy (VF) images for dysphagia management. The duration of upper esophageal sphincter opening (DUESO) is one important temporal swallow event, because reduced DUESO can result in pharyngeal residue and penetration/aspiration. VF is frequently used for evaluating swallowing but exposes patients to radiation and is not always feasible/readily available. High resolution cervical auscultation (HRCA) is a non-invasive, sensor-based dysphagia screening method that uses signal processing and machine learning to characterize swallowing. We investigated HRCA's ability to annotate DUESO and predict Modified Barium Swallow Impairment Profile (MBSImP) scores (component #14). We hypothesized that HRCA and machine learning techniques would detect DUESO with similar accuracy as human judges. Trained judges completed temporal kinematic measurements of DUESO on 719 swallows (116 patients) and 50 swallows (15 age-matched healthy adults). An MBSImP certified clinician completed MBSImP ratings on 100 swallows. A multi-layer convolutional recurrent neural network (CRNN) using HRCA signal features for input was used to detect DUESO. Generalized estimating equations models were used to determine statistically significant HRCA signal features for predicting DUESO MBSImP scores. A support vector machine (SVM) classifier and a leave-one-out procedure was used to predict DUESO MBSImP scores. The CRNN detected UES opening within a 3-frame tolerance for 82.6% of patient and 86% of healthy swallows and UES closure for 72.3% of patient and 64% of healthy swallows. The SVM classifier predicted DUESO MBSImP scores with 85.7% accuracy. This study provides evidence of HRCA's feasibility in detecting DUESO without VF images.

Correction to: An Exploratory Study of Hyoid Visibility, Position, and Swallowing-Related Displacement in a Pediatric Population

This letter notifies the readers of the Dysphagia journal of an error in the original published version of this manuscript, describing hyoid position during swallowing in children using an available pediatric dataset. A previously available open source spreadsheet tool had been used to calculate the position of the hyoid bone on lateral view videofluoroscopic images. An error in the mathematical formula built into the spreadsheet resulted in a reversal of reported results for measures of peak hyoid position in the X and Y planes of measurement. This erratum provides corrections to the results and interpretations of the original manuscript.

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.

Best Practices in Modified Barium Swallow Studies

Purpose The modified barium swallow study (MBSS) is a widely used videofluoroscopic evaluation of the functional anatomy and physiology of swallowing that permits visualization of bolus flow throughout the upper aerodigestive tract in real time. The information gained from the examination is critical for identifying and distinguishing the type and severity of swallowing impairment, determining the safety of oral intake, testing the effect of evidence-based frontline interventions, and formulating oral intake recommendations and treatment planning. The goal of this review article is to provide the state of the science and best practices related to MBSS. Method State of the science and best practices for MBSS are reviewed from the perspectives of speech-language pathologists (SLPs) and radiologists who clinically practice and conduct research in this area. Current quandaries and emerging clinical and research trends are also considered. Results This document provides an overview of the MBSS and standards for conducting, interpreting, and reporting the exam; the SLPs' and radiologist's perspectives on standardization of the exam; radiation exposure; technical parameters for recording and reviewing the exam; the importance of an interdisciplinary approach with engaged radiologists and SLPs; and special considerations for examinations in children. Conclusions The MBSS is the primary swallowing examination that permits visualization of bolus flow and swallowing movement throughout the upper aerodigestive tract in real time. The clinical validity of the study has been established when conducted using reproducible and validated protocols and metrics applied according to best practices to provide accurate and reliable information necessary to direct treatment planning and limit radiation exposure. Standards and quandaries discussed in this review article, as well as references, provide a basis for understanding the current best practices for MBSS.

Tracking Hyoid Bone Displacement During Swallowing Without Videofluoroscopy Using Machine Learning of Vibratory Signals

Identifying physiological impairments of swallowing is essential for determining accurate diagnosis and appropriate treatment for patients with dysphagia. The hyoid bone is an anatomical landmark commonly monitored during analysis of videofluoroscopic swallow studies (VFSSs). Its displacement is predictive of penetration/aspiration and is associated with other swallow kinematic events. However, VFSSs are not always readily available/feasible and expose patients to radiation. High-resolution cervical auscultation (HRCA), which uses acoustic and vibratory signals from a microphone and tri-axial accelerometer, is under investigation as a non-invasive dysphagia screening method and potential adjunct to VFSS when it is unavailable or not feasible. We investigated the ability of HRCA to independently track hyoid bone displacement during swallowing with similar accuracy to VFSS, by analyzing vibratory signals from a tri-axial accelerometer using machine learning techniques. We hypothesized HRCA would track hyoid bone displacement with a high degree of accuracy compared to humans. Trained judges completed frame-by-frame analysis of hyoid bone displacement on 400 swallows from 114 patients and 48 swallows from 16 age-matched healthy adults. Extracted features from vibratory signals were used to train the predictive algorithm to generate a bounding box surrounding the hyoid body on each frame. A metric of relative overlapped percentage (ROP) compared human and machine ratings. The mean ROP for all swallows analyzed was 50.75%, indicating > 50% of the bounding box containing the hyoid bone was accurately predicted in every frame. This provides evidence of the feasibility of accurate, automated hyoid bone displacement tracking using HRCA signals without use of VFSS images.

A Cross-Sectional, Quantitative Videofluoroscopic Analysis of Swallowing Physiology and Function in Individuals With Amyotrophic Lateral Sclerosis

Purpose To date, research characterizing swallowing changes in individuals with amyotrophic lateral sclerosis (ALS) has primarily relied on subjective descriptions. Thus, the degree to which swallowing physiology is altered in ALS, and relationships between such alterations and swallow safety and/or efficiency are not well characterized. This study provides a quantitative representation of swallow physiology, safety, and efficiency in a sample of individuals with ALS, to estimate the degree of difference in comparison to published healthy reference data and identify parameters that pose risk to swallow safety and efficiency. Secondary analyses explored the therapeutic effect of thickened liquids on swallowing safety and efficiency. Method Nineteen adults with a diagnosis of probable-definite ALS (El-Escorial Criteria-Revised) underwent a videofluoroscopic swallowing study, involving up to 15 sips of barium liquid (20% w/v), ranging in thickness from thin to extremely thick. Blinded frame-by-frame videofluoroscopy analysis yielded the following measures: Penetration-Aspiration Scale, number of swallows per bolus, amount of pharyngeal residue, degree of laryngeal vestibule closure (LVC), time-to-LVC, duration of LVC (LVCdur), pharyngeal area at maximum constriction, diameter of upper esophageal sphincter opening, and duration of UES opening (UESOdur). Measures of swallow physiology obtained from thin liquid trials were compared against published healthy reference data using unpaired t tests, chi-squared tests, and Cohen's d effect sizes (adjusted p < .008). Preliminary relationships between parameters of swallowing physiology, safety, and efficiency were explored using nonparametric Cochrane's Q, Friedman's test, and generalized estimating equations (p < .05). Results Compared to healthy reference data, this sample of individuals with ALS displayed a higher proportion of swallows with partial or incomplete LVC (24% vs. < 1%), increased time-to-LVC (d = 1.09), reduced UESwidth (d = 0.59), enlarged pharyngeal area at maximum constriction, prolonged LVCdur (d = 0.64), and prolonged UESOdur (d = 1.34). Unsafe swallowing (i.e., PAS ≥ 3) occurred more frequently when LVC was partial/incomplete or time-to-LVC was prolonged. Pharyngeal residue was associated with larger pharyngeal areas at maximum constriction. Unsafe swallowing occurred less frequently with extremely thick liquids, compared to thin liquids. No significant differences in pharyngeal residue were observed based on liquid thickness. Conclusions Quantitative videofluoroscopic measurements revealed moderate-to-large differences in swallow physiology between this sample of individuals with ALS and healthy reference data. Increased time-to-LVC, noncomplete LVC, and enlarged pharyngeal area at maximum constriction were associated with impaired swallow safety or efficiency. Thickened liquids may mitigate the risk of acute episodes of aspiration in individuals with ALS. Further work is needed to corroborate these preliminary findings and explore how swallowing profiles evolve throughout disease progression.

Effects of Expiratory Muscle Strength Training on Videofluoroscopic Measures of Swallowing: A Systematic Review

Purpose Expiratory muscle strength training (EMST) is increasingly utilized in dysphagia rehabilitation; however, little is known about the effects of this approach on swallowing function or physiology. We conducted a systematic review to appraise and synthesize evidence regarding the effects of EMST on videofluoroscopic measures of swallowing in individuals with medical diagnoses, in which dysphagia is a concern. Method A literature search was conducted according to Cochrane guidelines. Of 292 nonduplicate articles, 11 were judged to be relevant for review. These underwent detailed review for study quality, risk of bias evaluation, and synthesis of swallowing outcomes. Results The selected articles described EMST in a variety of patient populations using either the EMST150 or the Phillips Threshold positive expiratory pressure device. The typical protocol involved five sets of five breaths through the device (25 breaths/day), 5 days per week for 4 weeks. Exercise loads were set between 50% and 75% depending on the population, and treatment was typically supervised by a clinician weekly. The Penetration-Aspiration Scale was the most commonly reported videofluoroscopic outcome measure. Conclusions differed as to whether or not swallowing improved following a course of EMST. Differences in videofluoroscopy protocols, methods of summarizing participant performance, and statistical approaches across studies meant that meta-analysis of swallowing outcomes could not be completed. Conclusion This review failed to find clear evidence regarding the effects of EMST on videofluoroscopic measures of swallowing. Heterogeneity in the etiologies and baseline severity of dysphagia across studies and in the methods used to measure swallowing outcomes was a particular barrier to data synthesis.

How a personalised transportable folding device for seating impacts dysphagia

PURPOSE

A personalised transportable folding device for seating (DATP) on a standard seat was developed by an occupational therapist at the Toulouse University Hospital Centre (patent no. WO 2011121249 A1) based on the hypothesis that the use of a seat to assist with better positioning on any chair during meals modifies the sitting posture and has an impact on cervical statics which increases the amplitude of movements of the axial skeleton (larynx and hyoid bone) and benefits swallowing. The aim of this work is to demonstrate that an improvement in sitting posture with the help of the DATP, through Hyoid bone motion, has an impact on the quality of swallowing in a dysphagic population which benefits from the device in comparison to a dysphagic population which does not benefit from the device after 1 month of care. The secondary endpoints concern the evaluation of the impact on other characteristics of swallowing, posture, the acceptability of the device and the quality of life.

METHODOLOGY

This is a randomised comparative clinical trial. The blind was not possible for the patients but the examiner who evaluated the outcome criterion was blinded to the group to which the patient belonged. The outcome criterion was the measurement of the hyoid bone movement during swallowing. The other criteria were collected during the videofluoroscopic examination of swallowing and by use of a questionnaire. Fifty-six (56) patients were included: 30 in the group without device (D-) and 26 in the group with the device (D+). All the patients benefited from a training course on seating. Only the D+ patients participated in this course where the use of the device was explained and the device was then kept for use at home for 1 month.

RESULTS

A significant improvement was noted in the postural criteria before and after use, in favour of a better posture for the two groups (p < 0.001) and more hyoid bone motion in the D+ group. The difference was significant in the bivariate analysis for horizontal movement (p = 0.04). After adjustment of potential factors of confusion, we noted a significant mean difference for the three distances in the D+ group in comparison to the D- group, of + 0.33 (95% CI [+ 0.17; + 0.48]) for horizontal movement, + 0.22 (95% CI [+ 0.03; + 0.40]) for vertical movement and + 0.37 (95% CI = [+ 0.20; + 0.53]) for horizontal movement. However, the other parameters, and notably the other swallowing markers were not significantly modified by the use of the device.

CONCLUSION

The personalised transportable folding device for seating developed to reduce dysphagia has an action on hyoid bone motion during swallowing. However, this positive effect on an intermediate outcome criterion of the quality of swallowing was not associated with an improvement in swallowing efficiency in the study population. The diversity of diseases with which the patients in this study were afflicted is a factor to be controlled in future studies with this device.

Impaired Movement Scaling and Reduced Synchrony with Vestibule Closure Characterize Swallowing in Severe Dysphagia

The contribution of hyoid and laryngeal movement deficits to penetration or aspiration in dysphagia is unclear, partly due to large variations in normal hyolaryngeal kinematics for swallowing. In healthy volunteers, laryngeal and hyoid kinematics relate to the requirements for laryngeal vestibule closure suggesting a central schematic control of movement magnitude and patterning for airway protection. Our first aim was to determine if patients with severe dysphagia showed evidence of an impaired swallowing schema, by examining if their kinematic measures were related to their hyolaryngeal space before swallow onset, and if hyolaryngeal movement synchrony for vestibule closure was disrupted. Our second aim was to determine the kinematic measures that predicted bolus penetration and aspiration in dysphagia. The methods included two-dimensional measures of the hyoid and laryngeal anterior and superior displacement and velocity, and the change in laryngeal vestibule area made from videofluoroscopic swallow recordings of 21 healthy volunteers and 21 patients with dysphagia on tube feeding secondary to the stroke or head and neck cancer. The results demonstrated that the patients did not adapt their hyolaryngeal movements during swallowing to their initial hyolaryngeal space. Further, none of the patients' measures of hyoid or laryngeal peak velocity timing were synchronized with vestibule closure, demonstrating a disorganized movement patterning. Laryngeal elevation peak velocity independently predicted penetration and aspiration. In conclusion, the central schema for swallowing patterning was disturbed, impairing the integration of kinematic actions for airway protection in severe dysphagia, while laryngeal peak elevation velocity predicted penetration and aspiration on patient swallows.

Automatic Detection of the Pharyngeal Phase in Raw Videos for the Videofluoroscopic Swallowing Study Using Efficient Data Collection and 3D Convolutional Networks †

Videofluoroscopic swallowing study (VFSS) is a standard diagnostic tool for dysphagia. To detect the presence of aspiration during a swallow, a manual search is commonly used to mark the time intervals of the pharyngeal phase on the corresponding VFSS image. In this study, we present a novel approach that uses 3D convolutional networks to detect the pharyngeal phase in raw VFSS videos without manual annotations. For efficient collection of training data, we propose a cascade framework which no longer requires time intervals of the swallowing process nor the manual marking of anatomical positions for detection. For video classification, we applied the inflated 3D convolutional network (I3D), one of the state-of-the-art network for action classification, as a baseline architecture. We also present a modified 3D convolutional network architecture that is derived from the baseline I3D architecture. The classification and detection performance of these two architectures were evaluated for comparison. The experimental results show that the proposed model outperformed the baseline I3D model in the condition where both models are trained with random weights. We conclude that the proposed method greatly reduces the examination time of the VFSS images with a low miss rate.

Validation of the Normalized Laryngeal Constriction Ratio in Normal and Disordered Swallowing

PURPOSE

The timing of laryngeal vestibule closure (LVC) is important for airway protection during swallowing. However, it is unknown whether the extent of LVC contributes to airway protection. The goal of this study is to validate the extent of LVC via a measure called laryngeal constriction ratio (LCR).

METHODS

A retrospective analysis of videofluoroscopic swallows was conducted on 38 stroke participants and 40 healthy controls. The LCR was calculated by deriving a size-normalized area of airspace from a 1) maximum closed laryngeal vestibule and a 2) maximum open laryngeal airspace (at rest). Airway invasion severity was derived via the Penetration-Aspiration Scale score.

RESULTS

Six hundred forty-nine videofluoroscopic swallows were analyzed. A mixed model analysis revealed a statistically significant mean difference between the normalized laryngeal constriction ratios of healthy individuals (mean (m) = 0.003) versus older dysphagic patients (m = .026) (P = 0.001), quantifying less closure in older patients with dysphagia. Additionally, swallows with airway compromise had a statistically worse LCR when compared to swallows without airway compromise (P = 0.001).

CONCLUSION

The normalized LCR might be a valid fluoroscopic surrogate measure for LVC and, furthermore, airway compromise during swallowing. By investigating spatial measurements in the laryngeal vestibule during safe and unsafe swallows, the LCR provides a direction for further research to allow for critical examination of the physiology relating to closure degree in order to precisely detect and treat abnormalities during swallowing.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:E190-E198, 2020.

Temporal characteristics of laryngeal penetration and aspiration in stroke patients

BACKGROUND

Despite the importance of understanding penetration-aspiration (PA) in patients with stroke, the pathophysiology of PA remains unclear.

OBJECTIVES

This study aimed to investigate the temporal characteristics of PA in post-stroke patients in terms of the timing of the PA event and hyolaryngeal incoordination.

METHODS

Fifty-eight swallows (38 stroke patients), showing PA when swallowing a thin liquid, were included. The timing of PA was classified kinematically as before or during the swallow. The movement sequence of vertical laryngeal elevation, horizontal hyoid excursion, and epiglottic rotation were compared with healthy controls. Spatiotemporal measurements, videofluoroscopic dysphagia scale parameters were compared between subgroups.

RESULTS

Thirteen swallows (22.4%) were classified as PA before the swallow and 45 were classified as PA during the swallow (77.6%). Among the PA during the swallow, 26 (57.8%) swallows exhibited abnormal sequences of hyolaryngeal movements and 19 (42.2%) swallows showed normal sequences of hyolaryngeal movements compared with healthy controls. The onset time of horizontal hyoid excursion (P = 0.028), the time to maximal horizontal hyoid excursion (P = 0.010), and maximal epiglottic rotation (P = 0.030) were significantly more delayed in the PA during the swallow group than in the PA before the swallow group. In the swallows with abnormal sequential movements, the onset of horizontal hyoid excursion occurred significantly later than the onset of epiglottic rotation (P < 0.001). Pyriform sinus residue was observed significantly more often in the swallows with abnormal sequences (P = 0.030) than in the swallows with normal sequences.

CONCLUSIONS

The timing of PA can be classified as before and during the swallow with significantly different temporal characteristics. The horizontal movement of hyoid is the most important factor associated with the pathophysiology of PA in stroke patients.