The relationship between hyoid and laryngeal displacement and swallowing impairment

Tongue brushing enhances the myoelectric activity of the suprahyoid muscles in older adults: a six-week randomized controlled trial

Tongue brushing improves respiratory function in older adults. Considering connection between the respiratory-related and suprahyoid muscles, this study aimed to investigate whether tongue-brushing interventions can improve myoelectric activity during respiration. A six-week randomized controlled trial was conducted in Kitakyushu, Japan, with 50 participants aged ≥ 65 years. The participants were allocated to the intervention (tongue brushing with routine oral hygiene) or control (routine oral hygiene alone) groups. Surface electromyography (sEMG) was used to assess the myoelectric activity of the suprahyoid muscles during inhalation, exhalation, and forced vital capacity (FVC). A survey was conducted at baseline and the end of the follow-up period. Thirty-six participants were recruited for the analysis. The root mean squares (RMS) of sEMG during exhalation increased significantly at the end of the follow-up period compared with that at baseline in the intervention group [48.7 (18.0-177.5) vs. 64.9 (21.6-163.0), p = 0.001], but not in the control group. The generalized linear model revealed that the ratio of change in FVC was correlated with the change in the RMS of sEMG of the suprahyoid muscles during exhalation after adjusting for potential confounders. Tongue brushing enhances the myoelectric activity of the suprahyoid muscle.

Analysis of the suprahyoid muscles during tongue elevation: High-density surface electromyography as a novel tool for swallowing-related muscle assessment

BACKGROUND

High-density surface electromyography (HD-sEMG) has enabled non-invasive analysis of motor unit (MU) activity and recruitment, but its application to swallowing-related muscles is limited.

OBJECTIVE

We aimed to investigate the utility of HD-sEMG for quantitatively evaluating the MU recruitment characteristics of the suprahyoid muscles during tongue elevation.

METHODS

We measured the sEMG activity of the suprahyoid muscles of healthy participants during tongue elevation using HD-sEMG. Maximum voluntary contraction (MVC) was measured, followed by data collection during sustained and ramp-up tasks to capture suprahyoid muscle activity. Changes in the temporal/spatial MU recruitment patterns within individual suprahyoid muscles were analysed.

RESULTS

This study enrolled 16 healthy young adults (mean age: 27.8 ± 5.3 years; eight males and eight females). Increasing muscle force corresponded to a decrease in modified entropy and correlation coefficient and an increase in the coefficient of variation. No significant differences were observed between male and female participants.

CONCLUSION

The results of this study, consistent with those observed in other muscles, such as the vastus lateralis muscle, suggest that HD-sEMG is a valuable and reliable tool for quantitatively evaluating MU recruitment in the suprahyoid muscles. This measurement technique holds promise for novel assessments of swallowing function.

Morphological and functional changes of the geniohyoid muscle in elderly patients after hip fracture surgery: Comparison of ultrasound images with a focus on swallowing function

OBJECTIVE

The purpose of this study was to clarify, using ultrasound imaging, (1) whether the area and contraction of GH change in elderly patients after hip fracture surgery and (2) whether the changes in the area and contraction of GH are related to decline in swallowing function.

METHODS

The participants were 21 female patients over 65 years of age who underwent hip fracture surgery. The patients were divided into two groups based on the results of swallowing assessment by water drinking: One with normal swallowing function (NSF) and the other with suspected decline in swallowing function (DSF). Sagittal cross-sectional area (SA) of GH at rest and the shortening rate (SR) of GH upon contraction during swallowing were compared at two time points: immediately and 2 weeks after surgery. Wilcoxon signed-rank test was used for intra-group comparisons, and Mann-Whitney U-test was used for between-group comparisons.

RESULT

SA of GH decreased significantly at 2 weeks after surgery in both groups, regardless of their swallowing function. In the intra-group comparison, SR significantly decreased (worsened) only in DSF group. SR at 2 weeks after surgery was significantly higher in NSF than in the DSF. In the inter-group comparison, DSF showed a significantly smaller (worse) change of SR than NSF in 2 weeks after surgery.

CONCLUSION

Decrease in muscle mass, or atrophy, of GH observed in both NSF and DSF, did not coincide with the post-operative change in GH contraction of the two groups. The results suggest the importance of continuous swallowing assessment in the elderly individuals during their perioperative period.

Chemoradiation to the submental muscles alters hyoid movement during swallowing in a rat model

Hyolaryngeal dysfunction is a commonly reported swallowing problem after chemoradiation treatment for head and neck cancer. The displacement of the hyolaryngeal complex during swallowing protects the airway and assists in opening the upper esophageal sphincter. Activation of the submental muscles, specifically the mylohyoid and geniohyoid muscles, is thought to facilitate movement of the hyoid. The purpose of this study was to determine if targeted radiation to the submental muscles given concurrently with chemotherapy alters hyolaryngeal displacement 1 mo after treatment. We hypothesized that chemoradiation treatment would result in abnormal patterns of hyoid movement compared with controls. Furthermore, we propose that these changes are associated with alterations in bolus size and discoordination of the jaw during drinking. Eighteen rats underwent either chemoradiation, radiation, or no treatment. Radiation treatment was targeted to submental muscles using a clinical linear accelerator given in 12 fractions of 4 Gy (3 days per week). Cycles of 1 mg/kg of cisplatin were administered concurrently each week of radiation. One month posttreatment, videofluoroscopy swallow studies (VFSS) were performed in self-drinking rats using a fluoroscope customized with a high-speed camera. The hyoid, jaw, and hard palate were tracked during swallowing from VFSS. Hyoid kinematics were analyzed from the start to the end of hyoid movement, and parameters were compared with bolus size and jaw movement. Significant differences in hyoid retraction parameters were found postchemoradiation. Alterations in the trajectory of hyoid motion during swallowing were observed. The findings demonstrate early changes in hyoid motion during swallowing associated with chemoradiation treatment.NEW & NOTEWORTHY Chemoradiation treatment for head and neck cancer can cause functional impairments in swallowing, which can adversely affect quality of life. This study provides new evidence that chemoradiation targeted to the submental muscles provokes early adaptations in hyoid movement during swallowing, which correlate with changes in bolus size. We also demonstrate a method for tracking the hyoid during swallowing in a rat model of chemoradiation injury.

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 Oropharyngeal Resting Tremor on Swallowing Function in a Clinical Cohort of People with Parkinson's Disease

Parkinson's Disease (PD) is a progressive neurodegenerative disease, with hallmark symptomology typically consisting of tremor, bradykinesia, and rigidity. Though the classic "pill-rolling" rest tremor in the hand or upper limb are often the most salient, it can occur throughout the body including the lower limbs, jaw, face, or tongue. There have been investigations into other motor related phenomena potentially affecting swallow function in PwPD previously. However, there have been no investigations of how oropharyngeal resting tremor in structures such as the tongue or larynx explicitly affects swallowing physiology. A retrospective analysis of previously conducted VFSS on 34 patients diagnosed with idiopathic PD (IPD) was performed to examine how individuals that displayed resting tremor during VFSS (Tremor +) and those who did not (Tremor-) differ in swallowing function. Measures of swallowing function including timing intervals of key swallow events, post-swallow residue, and penetration-aspiration scale (PAS) scores were recorded, and key demographic information including time since diagnosis and medication status were extracted from the medical records available. Multivariate models were used to identify differences between tremor groups for timing intervals and post-swallow residue, and chi-squares were computed for differences in PAS score distribution by group and bolus. Sixty-eight percent (23/34) of this sample displayed oropharyngeal resting tremor in at least one structure during VFSS. There were no instances of other tremor types observed in this sample. All participants were taking medication to manage PD symptomology. Significant effects of tremor group were observed for swallow timing intervals related to airway closure (p < 0.001), post-swallow residue (p < 0.05), and swallow safety at the bolus level in the Tremor + group (p < 0.001). These results suggest that PwPD who present with resting tremor in oropharyngeal structures may manifest with different variations in swallowing physiology, including altered timings of swallow events, increased pharyngeal residue, and greater associations of airway invasion with thinner and larger volume boluses. This study highlights the need for substantially more research into how motor fluctuations and phenotypes of PwPD contribute to alterations in swallowing function.

Differences in the swallowing process of newborns and healthy preterm infants: first results with a non-invasive bioimpedance and electromyography measurement system

PURPOSE

Preterm infants (PI) have difficulty coordinating sucking, swallowing and breathing, and there is a risk of aspiration. The causes of this are not yet sufficiently understood. The aim of this study was to test a novel measurement device to measure breathing and pharyngeal processes involved in swallowing externally in everyday life to identify possible differences in neonates (NB) and PI.

METHODS

Forty healthy NB were studied at 4-8 weeks of age (mean: 6.7 weeks) and 20 healthy PI (mean gestational age 30.5 weeks) at postmenstrual age (PMA) 34/35 weeks (mean PMA 35.1 weeks) during a single feeding. Surface electrodes were used to measure bioimpedance and electromyography reflecting swallow-related changes in the pharynx and muscle activation of the tongue and submental muscles. A respiratory belt was combined with recording of the depth of chest movements and the occurrence of pauses in breathing.

RESULTS

Velocity and extent of pharyngeal closure did not differ significantly across the feeding period (velocity: p=0.09, closure: p=0.17), but during the first two suck-swallow bursts PI had greater velocity (p<0.001*) and extent of pharyngeal closure (p=0.004*) than NB. The duration of swallowing phases was significantly longer in PIs (p<0.001*), their muscle activation decreased faster (p<0.001*), and they had more pauses in breathing than NBs.

CONCLUSIONS

The novel measurement device allowed, for the first time in everyday life, the measurement of factors influencing swallowing and breath-swallow coordination in NBs and PIs. PIs showed differences from NBs most likely due to differences in muscle strength and condition.

Diagnostic value of a deep learning-based hyoid bone tracking model for aspiration in patients with post-stroke dysphagia

Objective

Hyoid bone movement is potentially related to aspiration risk in post-stroke dysphagia (PSD) patients but is difficult to assess quantitatively. This study aimed to measure the distance of hyoid bone movement more efficiently and accurately using a deep learning model and determine the clinical usefulness of the model in PSD patients.

Methods

This study included 85 patients with PSD within 6 months from onset. Patients were grouped into an aspiration group (n = 35) and a non-aspiration group (n = 50) according to the results of a videofluoroscopic swallowing study. Hyoid bone movement was tracked using a deep learning model constructed with the BiFPN-U-Net(T) architecture. The maximum distance of hyoid bone movement was measured horizontally (H max), vertically (V max), and diagonally (D max).

Results

Compared with the non-aspiration group, the aspiration group showed significant decreases in hyoid bone movement in all directions. The area under the curve of V max was highest at 0.715 with a sensitivity of 0.680 and specificity of 0.743. The V max cutoff value for predicting aspiration risk was 1.61 cm. The success of oral feeding at the time of discharge was significantly more frequent when hyoid movement was equal to or larger than the cutoff value although no significant relationship was found between hyoid movement and other clinical characteristics.

Conclusion

Hyoid bone movement of PSD patients can be measured quantitatively and efficiently using a deep learning model. Deep learning model-based analysis of hyoid bone movement seems to be useful for predicting aspiration risk and the possibility of resuming oral feeding.

Development and validation of a device for monitoring laryngeal motion during swallowing

Objectives: Hyolaryngeal movement during swallowing is essential to airway protection and bolus clearance. Although palpation is widely used to evaluate hyolaryngeal motion, insufficient accuracy has been reported. The Bando Stretchable Strain Sensor for Swallowing (B4S™) was developed to capture hyolaryngeal elevation and display it as waveforms. This study compared laryngeal movement time detected by the B4S™ with laryngeal movement time measured by videofluoroscopy (VF). Methods: Participants were 20 patients without swallowing difficulty (10 men, 10 women; age 30.6 ± 7.1 years). The B4S™ was attached to the anterior neck and two saliva swallows were measured on VF images to determine the relative and absolute reliability of laryngeal elevation time measured on VF and that measured by the B4S™. Results: The intra-class correlation coefficient of the VF and B4S™ times was very high [ICC (1.1) = 0.980]. A Bland-Altman plot showed a strong positive correlation with a 95% confidence interval of 0.00-3.01 for the mean VF time and mean B4S™ time, with a fixed error detected in the positive direction but with no proportional error detected. Thus, the VF and B4S™ time measurements showed high consistency. Conclusion: The strong relative and absolute reliability suggest that the B4S™ can accurately detect the duration of superior-inferior laryngeal motion during swallowing. Further study is needed to develop a method for measuring the distance of laryngeal elevation. It is also necessary to investigate the usefulness of this device for evaluation and treatment in clinical settings.

Evaluation of Swallowing Function in Relation to Oropharyngeal Dysphagia in Patients with Operated Unilateral Cleft Lip and Palate

OBJECTIVE

To determine the occurrence of oropharyngeal dysphagia (OD) signs and symptoms in patients with operated unilateral cleft lip and palate (CLP).

MATERIALS AND METHODS

This prospective study was conducted on 15 adolescents with operated unilateral CLP (CLP group) and 15 non-cleft volunteers (control group). Initially, the Eating Assessment Tool-10 (EAT-10) questionnaire was administered to subjects. OD signs and symptoms such as coughing, the sensation of choking, globus sensation, the need to clear the throat, nasal regurgitation, difficulties of bolus control multiple swallowing were evaluated by patient complaints and physical examination of swallowing function. Also, the Functional Outcome Swallowing Scale was used to determine the severity of the OD. Fiberoptic endoscopic evaluation of swallowing (FEES) with water, yogurt, and crackers was performed.

RESULTS

The prevalence of OD signs and symptoms based on patient complaints and physical examination of swallowing was low (range, 6.7 to 26.7%), and nonsignificant differences were observed between the groups for these parameters as well as for EAT-10 scores. According to the Functional Outcome Swallowing Scale findings, 11 of 15 patients with CLP were asymptomatic. Fiberoptic endoscopic evaluation of swallowing indicated that post-swallow pharyngeal wall residues with yogurt were significant in the CLP group with a prevalence of 53% ( P < 0.05), whereas differences between the groups in terms of cracker and water residues were nonsignificant ( P > 0.05).

CONCLUSION

OD in patients with repaired CLP was manifested mainly in the form of pharyngeal residue. However, it did not appear to cause significant increases in patient complaints compared with healthy individuals.

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.

Non-Contact Assessment of Swallowing Dysfunction Using Smartphone Captured Skin Displacements

Early and accurate dysphagia diagnosis is essential for reducing the risk of associated co-morbidities and mortalities. Barriers to current evaluation methods may alter the effectiveness of identifying at-risk patients. This preliminary study evaluates the feasibility of using iPhone X-captured videos of swallowing as a non-contact dysphagia screening tool. Video recordings of the anterior and lateral necks were captured simultaneously with videofluoroscopy in dysphagic patients. Videos were analyzed using an image registration algorithm (phase-based Savitzky-Golay gradient correlation (P-SG-GC)) to determine skin displacements over hyolaryngeal regions. Biomechanical swallowing parameters of hyolaryngeal displacement and velocity were also measured. Swallowing safety and efficiency were assessed by the Penetration Aspiration Scale (PAS), Residue Severity Ratings (RSR), and the Normalized Residue Ratio Scale (NRRS). Anterior hyoid excursion and horizontal skin displacements were strongly correlated with swallows of a 20 mL bolus (r_s = 0.67). Skin displacements of the neck were moderately to very strongly correlated with scores on the PAS (r_s = 0.80), NRRS (r_s = 0.41-0.62), and RSR (r_s = 0.33). This is the first study to utilize smartphone technology and image registration methods to produce skin displacements indicating post-swallow residual and penetration-aspiration. Enhancing screening methods provides a greater chance of detecting dysphagia, reducing the risk of negative health impacts.

Analysis of swallowing function after anterior/posterior surgery for cervical degenerative disorders and factors related to the occurrence of postoperative dysphagia

BACKGROUND CONTEXT

Dysphagia is one of the postoperative complications of cervical degenerative disorders. However, few studies have evaluated the pre- and postoperative swallowing function in detail.

PURPOSE

To analyze pre- and postoperative swallowing dynamics kinetically and investigate factors associated with postoperative dysphagia in patients with cervical degenerative disorders.

STUDY DESIGN

Retrospective review of prospectively collected data.

PATIENT SAMPLE

A total of 41 consecutive patients who underwent an anterior approach (anterior cervical discectomy/corpectomy and fusion (ACDF, ACCF), hybrid surgery (ACDF+ACCF) and total disc replacement) and 44 consecutive patients who underwent a posterior approach (laminoplasty and laminoplasty/laminectomy with fusion).

OUTCOME MEASURES

We compared the pre- and postoperative functional oral intake scale (FOIS), dysphagia severity scale (DSS), esophageal dysphagia, anterior/superior hyoid movement, upper esophageal sphincter (UES) opening, pharyngeal transit time, bolus residue scale (BRS), and the number of swallows.

METHODS

Videofluoroscopy was performed on the day before surgery and within two weeks after surgery. Data related to age, gender, disease, surgical procedure, surgical site, operative time, and blood loss were collected from the medical records. Pre- and postoperative data were compared for each item in the anterior and posterior approaches. The odds ratio of dysphagia after an anterior approach was also calculated.

RESULTS

In the anterior approach, DSS, FOIS, the anterior and superior hyoid movements, maximum UES opening, BRS, and number of swallows worsened postoperatively (p<.05, respectively). In the posterior approach, DSS, FOIS, the anterior hyoid movement, and BRS worsened postoperatively (p<.05, respectively). The factors associated with dysphagia were a proximal surgical site above C3 (OR: 14.40, CI: 2.84-73.02), blood loss >100 mL (OR: 9.60, CI: 2.06-44.74), an operative time >200 minutes (OR: 8.18, CI: 1.51-44.49), and an extensive surgical field of more than three intervertebral levels (OR: 6.72, CI: 1.50-30.07). The decline in swallowing function after the posterior approach was related to aging (p=.045).

CONCLUSIONS

Each approach may decrease swallowing function, especially because of the limitation on the anterior hyoid movement. Dysphagia after anterior approaches was associated with the operative site, operative time, and blood loss.

Functional outcomes of hyoid suspension in anterior oromandibular reconstruction

BACKGROUND

Hyoid suspension can be considered in major oromandibular reconstruction. The impact of hyoid suspension on flap viability, swallowing outcomes, airway, and long term radiographic hyoid position is unknown. The objective of this study is to describe outcomes after hyoid suspension in anterior mandibular reconstruction with fibular free flaps. We hypothesized hyoid suspension would not affect flap viability and would benefit functional outcomes.

METHODS

A retrospective cohort study was conducted in an academic tertiary medical center. The study consisted of 84 adults who underwent anterior mandibular reconstruction from February 2014 to September 2020. The primary outcome studied was the post-suspension flap viability. Secondary outcomes include pre/post-operative hyomental distance on computed-tomography, duration of perioperative tracheostomy, postoperative feeding tube dependence, and post-operative aspiration pneumonia.

RESULTS

A total of 84, predominantly male (66.5 %), patients with an average age of 58.9 ± 11.5 were included in the study. Of those that met inclusion criteria, 25 (29.4 %) underwent intraoperative hyoid suspension. Univariable analysis showed no significant association between resuspension and post-operative total flap loss (p = 0.864) or partial flap loss (p = 0.318). There was no association between hyoid suspension and any of the studied postoperative functional outcomes or radiographic measures.

CONCLUSIONS

Hyoid suspension is an option during oromandibular reconstruction and does not impact flap viability. The impact on functional outcomes and long-term hyoid position in this patient subset remains unclear.

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.

Brain Activation Site of Laryngeal Elevation During Swallowing: An fMRI Study

The object of this study is to investigate dysphagia caused by reduced laryngeal elevation in patients poststroke. The central mechanism of laryngeal elevation during swallowing was explored by comparing the brain activation area before and after treatment with that of healthy subjects. The treatment group included patients diagnosed with dysphagia poststroke that showed reduced laryngeal elevation. They were treated with electrical stimulation at the motor points of the muscles related to laryngeal elevation. Functional magnetic resonance imaging (fMRI) using the blood oxygenation level-dependent (BOLD) was used to observe brain activation of the normal healthy control group and treatment group during voluntary swallowing. Independent sample t test and paired sample t test were used to analyze the differences in brain activation between and within the groups. Compared with the control group, no activation was observed in the brainstem and putamen regions of the experimental group before treatment. Statistics showed that the experimental group had a wider range of brain activation than the control group pretreatment, including the left supplementary motor area, the cingulate gyrus, the inferior frontal gyrus, the right thalamus, and the right putamen. After the electrical stimulation, the brain stem subregion, the left cerebellar lobule IV and V, and parts of the cerebral cortex were more active, while the left supplementary motor area, paracentral lobule, and occipital lobule were less active post-treatment. (1) The brainstem and putamen are the specific brain regions that control laryngeal movement. (2) The enhanced activation of the cortical-basal ganglia-thalamic circuit after stroke is a compensatory mechanism. (3) The improvement of hyoid bone elevation was related to the enhanced activation of the IV and V lobes of the cerebellar hemisphere. The over-activation of the supplementary motor area poststroke would subside once the motor function improved.

Cervical Vertebral Height Approximates Hyoid Displacement in Videofluoroscopic Images of Healthy Adults

Clinicians and researchers commonly judge the completeness of hyoid displacement from videofluoroscopic swallow study (VFSS) videos. Judgments made during the clinical exam are often subjective, and post-examination analysis reduces the measure's immediate value. This study aimed to determine the validity and feasibility of a visual, anatomically scaled benchmark for judging complete hyoid displacement during a VFSS. The third and fourth cervical vertebral bodies (C3 and C4) lie at roughly the same vertical position as the hyoid body and are strongly correlated with patient height. We hypothesized that anterior and superior displacement of the hyoid bone would approximate the height of one C3 or C4 body during safe swallows. Trained raters marked points of interest on C3, C4, and the hyoid body on 1414 swallows of adult patients with suspected dysphagia (n = 195) and 50 swallows of age-matched healthy participants (n = 17), and rated Penetration Aspiration Scale scores. Results indicated that the mean displacements of the hyoid bone were greater than one C3 unit in the superior direction for all swallows from patient and healthy participants, though significantly and clinically greater in healthy participant swallows (p < .001, d > .8). The mean anterior and superior displacements from patient and healthy participant swallows were greater than one C4 unit. Results show preliminary evidence that use of the C3 and/or C4 anatomic scalars can add interpretive value to the immediate judgment of hyoid displacement during the conduct of a clinical VFSS examination.

Characteristics of submental muscles function and hyoid bone movement in patients with dysphagia after stroke

BACKGROUND

Dysphagia is one of the common complications after stroke. Dysphagia significantly increases the probability of serious adverse consequences. The purpose of this study was to compare the characteristics of submental muscles electromyography and hyoid motion parameters between patients with dysphagia after stroke and healthy controls, and whether there is a synergistic effect between the function of the submental muscles and the movement of the hyoid.

METHODS

Fifteen patients with post-stroke dysphagia and fifteen healthy adults simultaneously underwent the videofluoroscopic and surface electromyography of the submental muscles while swallowing 5 ml of concentrated liquid barium sulphate. The electromyographic signal of the submental muscles was analysed along with parameters of hyoid movement.

FINDINGS

Stage transition duration and duration of surface electromyographic activity were extended significantly in post-stroke dysphagia patients(P < 0.05). Surface electromyography amplitude and hyoid movement were significantly reduced in patients (P < 0.05). There was a significant correlation between the maximum hyoid movement distance and the peak sEMG amplitude in healthy controls (r = 0.660, P = 0.014), but not in patients with dysphagia after stroke (r = 0.425, P = 0.148).

INTERPRETATION

Submental muscles electromyographic signal changes in patients may be the result of uncoordinated muscle contractions and decreased muscle strength. Furthermore, the reduced hyoid movement distance may be due to impaired function of the submental muscles. In addition, the submental muscles and hyoid movement or other swallowing structures functions were impaired to varying degrees, resulting in the disappearance of the correlation between the maximum movement distance of the hyoid and the peak amplitude.

Longitudinal Analysis of Swallowing Displacement Kinematics After Oropharyngeal Cancer Treatment

BACKGROUND/OBJECTIVE

Quantitative swallowing displacement kinematics evolve in patients treated for oropharyngeal squamous cell carcinoma (OPSCC). We aimed to longitudinally assess these measurements and correlate them with functional swallowing outcomes.

METHOD

A retrospective review was conducted on patients with OPSCC treated with definitive (chemo)radiation ([C]RT) or surgery with adjuvant (chemo)radiation (S-[C]RT) who completed at least two videofluoroscopic swallow studies (VFSS). Longitudinal analysis was accomplished via mixed-effects logistic regression for the Functional Oral Intake Scale (FOIS), and Penetration Aspiration Scale (PAS), and mixed-effects linear regression for kinematic measures. Spearman's correlation was conducted between changes in FOIS/PAS and kinematic measures.

RESULTS

Ninety-seven patients (76 males; mean age 61) completed 245 VFSS studies. A total of 94% had human papillomavirus (HPV)/p16 positive OPSCC and 74% were T0-T2. Sixty-four patients underwent [C]RT while 33 patients underwent S-[C]RT. After treatment, posterior pharyngeal wall at hold (PPWhold) increased 3.2 standard deviation (SD) between 0 and 6 months (p < 0.001), then decreased 2.2 SD between 6 and 12 months (p < 0.001) and did not return to baseline. Hyoid-to-larynx (HL) (p = 0.046) and maximal hyoid displacement (Hmax) + HL (p = 0.042) increased between 6 and 12 months. Hmax (p = 0.020) and Hmax + HL (p < 0.001) decreased between 12-24 months beyond baseline values. The decrease in HL and increase in PPWhold (p < 0.05) correlated with an increase in PAS. From baseline, increased pharyngeal constriction ratio correlated with decreased FOIS and PPWhold (p < 0.05).

CONCLUSIONS

Quantitative swallowing kinematic measures can effectively track changes in swallowing physiology. Increased PPWhold and restricted hyolaryngeal movement were seen in patients with OPSCC after treatment and correlated with a change in swallowing outcome, emphasizing the need for serial VFSS monitoring and targeted intervention.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

Developing a Protocol for Quantitative Analysis of Liquid Swallowing in Children

PURPOSE

Objective measures in videofluoroscopic swallow studies (VFSSs) can quantify swallow biomechanics. There are a wide array of validated measures studied in infants, children, and adults. There is a need for a pediatric VFSS protocol that consists of a small number of vital, time efficient, and clinically relevant measures. In this study, we aimed to establish a standard protocol for quantitative VFSS analysis in children.

METHOD

Protocol development began with a systematic literature review, which identified 22 quantitative and eight descriptive measures available in the literature. A pediatric VFSS database of 553 children was collected using a standardized VFSS protocol. Studies were evaluated using the 30 previously reported measures covering displacement and timing parameters as well as penetration-aspiration and residue. Measures were tested for rater reliability and internal consistency. Measures meeting acceptable values for protocol inclusion were included in the final protocol (Cronbach's alpha > .53).

RESULTS

Interrater and intrarater reliability of 17 measures met acceptable reliability levels. During internal consistency testing, we removed six further measures based on Cronbach's alpha levels indicating that two or more measures were equivalent in measuring the same aspect of swallow biomechanics in children. A VFSS protocol of reliable, valid, and obtainable objective quantitative (n = 6) and descriptive measures (n = 3) with separate protocols for young infants (≤ 9 months) and older children was established.

CONCLUSIONS

A standardized quantitative VFSS protocol for children has been developed to suit two age groups (≤ 9 and > 9 months old). Consistent VFSS administration and reporting support assessment over time and across disease groups. Future research should focus on how this information can be used by clinicians to produce individualized treatment plans for children with swallowing impairment.

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.

Correlating muscle resection with functional swallow outcomes: An anatomic framework informed systematic review of the literature

OBJECTIVE

To perform a systematic review of studies reporting swallow-associated outcomes in patients who received surgery for head and neck cancer (HNC), informed by an anatomic and physiologic framework of pharyngeal phase of swallowing (Pearson's dual-sling model).

METHODS

PUBMED and Google Scholar databases were searched for peer-reviewed papers published between 1990 and 2019 using relevant MeSH terms. Exclusion criteria were 1) discussions comparing reconstruction techniques, 2) case-report/series (n < 10), 3) perspective articles, 4) papers comparing objective instrumental methods of swallowing evaluation, 5) animal/cadaver studies, 6) no instrumental or validated swallow assessment tools used, 7) papers that discuss/include radiotherapy treatment, 8) systematic reviews, 9) papers that discuss swallow training or rehabilitation methods. Two investigators reviewed papers meeting inclusion/exclusions criteria. Muscles resected, anatomic resection site, swallow outcomes, and patient treatment variables were collected.

RESULTS

A total of 115,020 peer-reviewed papers were identified. 74 papers were relevant to this review, 18 met inclusion and exclusion criteria, and none discussed surgical impact on the pharyngeal phase of swallowing using Pearson's dual-sling model. Most papers discussed the effect of tongue-base, supraglottic, or regional anatomic resection. Post-surgical resection Follow-up times ranged from 1 to 13 months. 67% of studies used objective instrumental swallow studies; 22% used patient reported outcome measures. Follow up time since surgical resection, time to feeding tube removal, feeding tube present/absent, aspiration severity were used to define dysphagia endpoints.

CONCLUSIONS

To date, no surgical HNC studies have used the dual-sling mechanism to guide study design, and dysphagia assessment has been inconsistent. To counsel patients on the effects of surgery on pharyngeal phase of swallow function, specialists need physiologically grounded research that correlates muscles resected with consistent measures of swallow function.

Locational effects on oral microbiota among long-term care patients

Background

Dysbiosis of oral microbiota is the cause of many diseases related to oral and general health. However, few Asia-based studies have evaluated the role of oral microbiota in patients receiving long-term care. Thus, new indications are needed for early prevention and risk management based on information derived from the oral microbiota.

Methods

We used next-generation sequencing (NGS) to identify the oral bacterial composition and abundance in patients receiving long-term care: 20 from the outpatient department (OPD) and 20 home-care patients. Their microbial compositions, taxonomy, and alpha/beta diversity were characterized.

Results

Microbiota from the two groups showed different diversity and homogeneity, as well as distinct bacterial species. A more diverse and stable microbial population was observed among OPD patients. Our findings indicated that home-care patients had a higher risk of oral diseases due to the existence of dominant species and a less stable microbial community.

Conclusion

This work was the first in Taiwan to use NGS to investigate the oral microbiota of long-term care patients. Our study demonstrated the potential use of dominant bacterial species as biomarkers for the risk management of posttreatment complications.

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.

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.

Examination of Suprahyoid Muscle Resection and Other Factors Affecting Swallowing Function in Patients With Advanced Oral Cancer After Surgical Resection and Reconstruction

Dysphagia is one of the most common adverse effects associated with oral cancer therapy and could greatly impair postoperative quality of life. The objective of this study was to analyze postoperative swallowing outcomes and factors influencing postoperative swallowing function in patients with advanced oral cancer who underwent primary reconstruction after surgical resection to identify patients at risk of experiencing severe dysphagia after immediate reconstruction of surgical defects, and to determine an ideal approach to provide appropriate perioperative interventions. The swallowing status was evaluated at 4 week postoperatively using the Functional Oral Intake Scale. We also analyzed the effects of patient, tumor, surgical, and other factors on postoperative swallowing function. The study included 67 patients. At 4 weeks postoperatively, 11 patients showed reduced swallowing function, whereas 56 patients showed good swallowing function. The number of resected suprahyoid muscles (odds ratio, 1.55; 95% confidence interval, 1.03-2.32; P=0.035) was an independent factor influencing postoperative swallowing function. Thus, among patients who underwent radical resection of oral cancer with primary reconstruction, those with extensive resection of the suprahyoid muscles were at higher risk of developing postoperative dysphagia. These findings are expected to facilitate increased vigilance for dysphagia, better counseling, and appropriate rehabilitation interventions.

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.

Jaw-retraction exercise increases anterior hyoid excursion during swallowing in older adults with mild dysphagia

OBJECTIVES

The present study aimed to evaluate the effectiveness of a newly designed jaw-retraction exercise for strengthening the geniohyoid muscle and thus improving the anterior movement of the hyoid bone during swallowing.

BACKGROUND

Although previous studies suggest a relationship between anterior hyoid excursion and upper esophageal sphincter (UES) opening, there are currently no reports of physical exercises without the use of special equipment that can effectively improve this movement of the hyoid bone during swallowing.

MATERIALS AND METHODS

This before-after study included patients presenting to the authors' hospital with mild dysphagia (Level 5 on the Dysphagia Outcome and Severity Scale). The participants were instructed to perform a jaw-retraction exercise designed to strengthen the geniohyoid muscle. Each participant was instructed to perform two sets of the exercise daily for four weeks, with each set consisting of five repetitions. Before and after the four-week training period, videofluoroscopic swallowing studies were performed and later analysed.

RESULTS

Twenty-five patients with a median age of 77 were included. The median peak anterior hyoid position before and after exercise were 129.82 and 132.74 (%C2-C4 length), respectively, and this increase was found to be significant (P = .007). The median extent of UES opening before and after exercise were 8.6 and 9.3 (mm), respectively, and this increase was also found to be significant (P = .040).

CONCLUSION

Our findings demonstrate that the jaw-retraction exercise can effectively improve the anterior movement of the hyoid bone. This exercise may be effective in individuals with oral frailty when signs of swallowing disorders are observed.

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.

Automatic annotation of cervical vertebrae in videofluoroscopy images via deep learning

Judging swallowing kinematic impairments via videofluoroscopy represents the gold standard for the detection and evaluation of swallowing disorders. However, the efficiency and accuracy of such a biomechanical kinematic analysis vary significantly among human judges affected mainly by their training and experience. Here, we showed that a novel machine learning algorithm can with high accuracy automatically detect key anatomical points needed for a routine swallowing assessment in real-time. We trained a novel two-stage convolutional neural network to localize and measure the vertebral bodies using 1518 swallowing videofluoroscopies from 265 patients. Our network model yielded high accuracy as the mean distance between predicted points and annotations was 4.20 ± 5.54 pixels. In comparison, human inter-rater error was 4.35 ± 3.12 pixels. Furthermore, 93% of predicted points were less than five pixels from annotated pixels when tested on an independent dataset from 70 subjects. Our model offers more choices for speech language pathologists in their routine clinical swallowing assessments as it provides an efficient and accurate method for anatomic landmark localization in real-time, a task previously accomplished using an off-line time-sinking procedure.

Behavioral Interventions Targeting Insufficient Upper Esophageal Sphincter Opening During Swallowing: A Scoping Review

The upper esophageal sphincter (UES) plays a central role in safe swallowing. Impaired UES opening is commonly observed in individuals presenting with impaired swallowing and various interventions are available aiming to improve bolus passage across the UES during swallowing. This scoping review addressed the following question: Which behavioral interventions are available to improve UES opening for deglutition? We searched MEDLINE, CINAHL, Ovid Emcare, Web of Science, SCOPUS and ProQuest for studies that met the following criteria: i. behavioral interventions targeting UES opening ii. performed over a period of time, which iii. were assessed using UES specific outcome measures. Study quality was assessed using the Joanna Briggs Institute and GRADE frameworks. Data were extracted and synthesized into dominant themes. Of the 357 studies originally identified, 15 met inclusion criteria and reported interventions that were grouped into four intervention types: (1) floor of mouth exercises that were sub-categorized into the Shaker exercise and other strengthening exercises, (2) Mendelsohn maneuver, (3) lingual exercises and (4) mixed exercise paradigms. Across the included studies, varying levels of success in improving various aspects of UES opening metrics were reported. Nine of 15 studies evaluated patients with demonstrated swallowing impairment, whereas six studies evaluated healthy adults. Quality assessment revealed significant variability in study quality, unclear reporting of participant training and treatment fidelity, as well as training dosage. The evidence base for the four behavioral intervention approaches targeting deglutitive UES opening is limited. The translation of existing evidence to clinical practice is hindered by small sample sizes and methodological limitations. Further research in this space is warranted.

Effect of dentures on pharyngeal swallowing function in patients with dysphagia

AIM

Dentures play an important role in improving masticatory and oropharyngeal swallowing functions in some edentulous patients without dysphagia. However, few studies have been conducted on patients with dysphagia. This study investigated the effect of dentures on pharyngeal swallowing function in patients with dysphagia.

METHODS

Older inpatients with dysphagia who used well-fitting dentures were included in the study. Videofluoroscopic swallowing study findings with and without dentures were compared. Pharyngeal residue and area as spatial, the distance between the maxilla and mandible, hyoid bone/laryngeal displacement, and upper esophageal sphincter opening as kinematics, oral/pharyngeal transit time as temporal measurements, and patient-reported symptoms were evaluated. The primary outcome was the pharyngeal residue measured using the normalized residue ratio scale. Comparisons were made using the paired t-test, Wilcoxon signed-rank test and Fisher's exact test.

RESULTS

The mean age of the 27 participants was 86.1 ± 6.8 years. The vallecular residue was more in those without dentures (with dentures: 0.01 [0-0.02], without dentures: 0.03 [0-0.08]; P = 0.003). The pyriform sinus residue showed no significant difference. Denture removal significantly increased the pharyngeal area. The distance between the maxilla and mandible decreased in the absence of dentures, and other kinematic measurements showed no significant differences. Oral/pharyngeal transit time was prolonged without dentures.

CONCLUSIONS

Morphological changes caused by the removal of dentures led to pharyngeal expansion, which may result in increased vallecular residue. A treatment plan that considers the effect of dentures on pharyngeal swallowing function may provide rehabilitation that is more effective. Geriatr Gerontol Int 2021; 21: 907-912.

Outcomes of manual therapy on the biomechanics of swallowing in individuals with COPD

PURPOSE

Several swallowing disorders have been reported in chronic obstructive pulmonary disease (COPD) patients due to the mechanical disadvantage of the respiratory muscles caused by hyperinflation. To date, no reports have been found in the literature among the therapeutic strategies on the use of manual therapy (MT) to manage swallowing disorders in COPD. The aim of the study was to verify the outcomes of a TM program on the biomechanics of swallowing of individuals with COPD.

METHODS

18 individuals with a mean age of 66.06 ± 8.86 years, 61.1% (11) men, and a FEV1% mean of 40.28 ± 16.73 were evaluated before and after TM. The measures analyzed were: oral transit time, pharyngeal transit time (PTT), number of swallows, vallecular (VL) residue and pyriform sinuses, penetration/aspiration and hyolaryngeal excursion in liquid and pasty consistencies.

RESULTS

A significant difference was found in PTT (p=0.04), VL residue (p=0.03), maximal hyoid elevation (p=0.003), and displacement of hyoid (p=0.02) in the pasty consistency. In the liquid consistency, we found a decrease in VL residue (p=0.001).

CONCLUSION

The MT program influenced the swallowing biomechanics of COPD patients demonstrated by a reduction in PTT and VL residue and increased hyoid elevation and displacement in the pasty consistency. In the liquid consistency, a decrease in VL residue was found.

Hyoid Bone Tracking in a Videofluoroscopic Swallowing Study Using a Deep-Learning-Based Segmentation Network

Kinematic analysis of the hyoid bone in a videofluorosopic swallowing study (VFSS) is important for assessing dysphagia. However, calibrating the hyoid bone movement is time-consuming, and its reliability shows wide variation. Computer-assisted analysis has been studied to improve the efficiency and accuracy of hyoid bone identification and tracking, but its performance is limited. In this study, we aimed to design a robust network that can track hyoid bone movement automatically without human intervention. Using 69,389 frames from 197 VFSS files as the data set, a deep learning model for detection and trajectory prediction was constructed and trained by the BiFPN-U-Net(T) network. The present model showed improved performance when compared with the previous models: an area under the curve (AUC) of 0.998 for pixelwise accuracy, an accuracy of object detection of 99.5%, and a Dice similarity of 90.9%. The bounding box detection performance for the hyoid bone and reference objects was superior to that of other models, with a mean average precision of 95.9%. The estimation of the distance of hyoid bone movement also showed higher accuracy. The deep learning model proposed in this study could be used to detect and track the hyoid bone more efficiently and accurately in VFSS analysis.

The Relationships Between Radiation Dosage and Long-term Swallowing Kinematics and Timing in Nasopharyngeal Carcinoma Survivors

This study aimed to investigate the relationship between intensity-modulated radiation therapy (IMRT) dosimetry and swallowing kinematic and timing measures. Thirteen kinematic and timing measures of swallowing from videofluoroscopic analysis were used as outcome measures to reflect swallowing function. IMRT dosimetry was accessed for thirteen swallowing-related structures. A cohort of 44 nasopharyngeal carcinoma (NPC) survivors at least 3 years post-IMRT were recruited. The cohort had a mean age of 53.2 ± 11.9 years, 77.3% of whom were male. There was an average of 68.24 ± 14.15 months since end of IMRT; 41 (93.2%) had undergone concurrent chemotherapy. For displacement measures, female sex and higher doses to the cricopharyngeus, glottic larynx, and base of tongue were associated with reduced hyolaryngeal excursion and pharyngeal constriction, and more residue. For timing measures, higher dose to the genioglossus was associated with reduced processing time at all stages of the swallow. The inferior pharyngeal constrictor emerged with a distinctly different pattern of association with mean radiation dosage compared to other structures. Greater changes to swallowing kinematics and timing were observed for pudding thick consistency than thin liquid. Increasing radiation dosage to swallowing-related structures is associated with reduced swallowing kinematics. However, not all structures are affected the same way, therefore organ sparing during treatment planning for IMRT needs to consider function rather than focusing on select muscles. Dose-response relationships should be investigated with a comprehensive set of swallowing structures to capture the holistic process of swallowing.

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.

Detection of poststroke oropharyngeal dysphagia with swallowing screening by ultrasonography

There are currently no standard evaluation tools for poststroke neurogenic oropharyngeal dysphagia. We previously suggested calculating the relative movements of the hyoid bone and larynx by ultrasonography to evaluate swallowing movement. Swallowing movement is altered in neurogenic oropharyngeal dysphagia. Therefore, the present study aimed to verify whether an ultrasonographic evaluation of swallowing movement facilitates the detection of neurogenic oropharyngeal dysphagia. Eighteen healthy male elderly participants (the healthy group) and 18 male stroke patients diagnosed with neurogenic oropharyngeal dysphagia (the dysphagia group) were enrolled. Participants swallowed 5 mL of liquid and water with an adjusted viscosity and the movements of the hyoid bone and larynx were visualized by ultrasonography. The results obtained revealed significant differences in laryngeal duration (static phase), laryngeal displacement (elevation phase), and the hyoid bone–laryngeal motion ratio (HL motion ratio) between the two groups. A multiple regression analysis was performed to adjust for confounding factors, and laryngeal duration (static phase) and the HL motion ratios were identified as factors affecting dysphagia. In the receiver operation characteristic curve of the two variations, the area under the curve for laryngeal duration (static phase) was 0.744 and the cut-off was 0.26 sec with 72.2% sensitivity and 88.9% specificity; the area under the curve for the HL motion ratio was 0.951 and the cut-off was 0.56 with 88.9% sensitivity and 88.9% specificity. Therefore, the objective evaluation of hyoid bone and larynx movements during swallowing by ultrasonography facilitated the detection of neurogenic oropharyngeal dysphagia.

Effects of Varying Transcutaneous Electrical Stimulation Pulse Duration on Swallowing Kinematics in Healthy Adults

Prior research in swallowing physiology has suggested that using submental transcutaneous electrical stimulation (TES) with short pulse duration (PD) (300 μs) may enhance the impact on deep extrinsic tongue muscles, thereby pulling the tongue down during swallowing. However, it was unclear whether that same TES protocol could have a differential impact on hyolaryngeal kinematics and timing. This study aimed to compare the effect of submental TES with varying PDs on anterior and superior hyolaryngeal kinematics and timing both at rest and during swallowing in healthy adults. Twenty-four healthy adults between the ages of 22 and 77 participated in this study. Anterior and superior hyolaryngeal excursion magnitude and duration measures were collected using videofluoroscopic swallowing study. Each subject swallowed three 10 ml pudding trials under three conditions: no TES, TES with short PD (300 μs), and TES with long PD (700 μs). TES was delivered using two-channel surface electrodes in the submental area. In both short and long PD conditions, TES amplitude was gradually increased until participants reached their maximum tolerance level. Videofluoroscopic data were analyzed using VideoPad Video Editor and Image J programs. One-way repeated measure ANOVAs were conducted to identify within-subject effect of TES condition. For hyoid movement, TES with short PD selectively placed the hyoid bone on a more anterior position at rest and reduced anterior hyoid excursion during swallowing compared with the no TES condition. Regarding laryngeal movement, both TES protocols resulted in the larynx taking on a more anterior position at rest and reduced anterior laryngeal excursions during swallowing when compared with the no TES condition. Varying PDs had no significant effect on the superior hyoid and laryngeal movements at rest and during swallowing. Both TES protocols induced shorter hyoid elevation duration during swallowing Findings suggest that though both TES protocols demonstrated a comparable impact on reducing anterior laryngeal excursions, the TES protocol with short PD had an enhanced effect on reducing anterior hyoid excursion during swallowing. This reduced range of motion may result from stimulating the deep submental muscles, which primarily place the hyoid and larynx into a more forward position before swallowing onset. Overall, the TES protocol with short PD may have an increased benefit in facilitating swallowing in patients with dysphagia.

Predicting penetration-aspiration through quantitative swallow measures of children: a videofluoroscopic study

PURPOSE

Quantitative measures have improved the reliability and accuracy in interpretation and reporting of videofluoroscopy (VFSS). Associations between quantitative VFSS measures and swallow safety in children are not widely reported. The ability to predict aspiration in children, even if not observed during brief VFSS, will improve diagnostic reporting and potentially reduce the need for extended radiation time. The aims of this study were to determine associations between quantitative fluoroscopic swallow measures and penetration-aspiration and to predict likelihood of penetration-aspiration.

METHODS

We selected videofluoroscopic data of 553 children from a pediatric hospital database for this single-center retrospective observational study. A standard protocol of VFSS administration was used and data were recorded at 30 frames-per-second. A set of quantitative and descriptive swallow measures was obtained using a specialized software with satisfactory inter-rater and intra-rater reliability. Binomial logistic regression with backward likelihood ratio was conducted, while controlling for age, gender, and etiology.

RESULTS

We found bolus clearance ratio (BCR), pharyngeal constriction ratio (PCR), duration to hyoid maximal elevation (Hdur), and total pharyngeal transit time (TPT) to be predictive of penetration-aspiration in children. PCR was the most predictive of penetration-aspiration in children (61.5%). Risk of aspiration was more than 100 times, when BCR =  ≥ 0.1, TPT =  ≥ 2 s, Hdur =  > 1 s or PCR =  ≥ 0.2 (p < 0.05 for all measures).

CONCLUSION

The results confirm the potential of objective quantitative swallow measures in predicting the risk of aspiration in children with dysphagia. These parameters provide predictive measures of aspiration risk that are clinically useful in identifying children of concern, even if no aspiration is observed during VFSS.

Variations in Hyoid Kinematics Across Liquid Consistencies in Healthy Swallowing

Purpose Judgments regarding hyoid movement are frequently included in evaluations of swallowing. However, the literature lacks reference values for measures of hyoid kinematics in healthy swallowing. This study explores hyoid movement across the continuum from thin to extremely thick liquids. Method Participants were 39 healthy adults under the age of 60 years (19 men) who underwent videofluoroscopy involving three sips each of 20% w/v thin barium and six sips each of slightly, mildly, moderately, and extremely thick barium. Half of the thickened stimuli were prepared using xanthan gum; and half, with a starch-based thickener. Sip volume was derived from pre- and post-sip cup weights. Hyoid position was tracked frame-by-frame relative to the anterior-inferior corner of C4. Measures of peak hyoid position (along the XY axis) were normalized to a C2-C4 scalar, and measures of time-to-peak position, speed, and time-to-peak speed were derived. As a first step, Spearman's correlations confirmed the influence of sip volume on these hyoid measures. Linear mixed-effects models then explored the effects of stimulus, sip volume, and task repetition on the dependent variables. Results The data set comprised 975 swallows with available hyoid tracking data. Sip volume was correlated with peak hyoid XY position (rs = .15, p < .01), time-to-peak position (rs = -.15, p < .05), and speed (rs = .13, p < .01). No significant differences in hyoid kinematics were found across stimuli. Conclusion Measures of hyoid movement in healthy swallowing remain stable across the range from thin to extremely thick liquids with no systematic alterations in hyoid position or kinematics.

Classification of Stroke Patients With Dysphagia Into Subgroups Based on Patterns of Submental Muscle Strength and Skill Impairment

OBJECTIVES

To identify and characterize subgroups of stroke patients with clinical signs of dysphagia, based on swallowing-related strength and skill impairments of the submental muscle group.

DESIGN

Prospective observational study.

SETTING

Inpatient rehabilitation centers and community dwellings.

PARTICIPANTS

Individuals (N=114), including stroke patients with dysphagia (n=55) and 2 control groups including myopathic patients with dysphagia (n=19) and healthy volunteers (n=40) were included in this study.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Novel clinical assessment of strength (force generation) and skill (spatial and temporal precision of muscle activation) of the submental muscle group during swallowing and nonswallowing behaviors, using surface electromyography and dynamometry.

RESULTS

Hierarchical cluster analysis revealed 4 clusters, which could be broadly characterized as cluster 1: intact strength and skill, cluster 2: poor strength and poor nonswallowing skill, cluster 3: poor strength, and cluster 4: poor strength and poor swallowing skill. Membership in cluster was significantly associated with medical diagnosis (P<.001). The majority of healthy and myopathic participants were assigned to clusters 1 and 3, respectively, whereas stroke patients were found in all 4 clusters. Skill outcome measures were more predictive of cluster assignment than strength measures.

CONCLUSIONS

Although healthy and myopathic participants demonstrated predominantly homogeneous swallowing patterns of submental muscle function within their etiology, several subgroups were identified within stroke, possibly reflecting different subtypes of swallowing function. Future research should focus on the nature and rehabilitation needs of these subtypes. Assessment of skill in swallowing may be an important but overlooked aspect of rehabilitation.

Determining the Underlying Relationship Between Swallowing and Maximum Vocal Pitch Elevation: A Preliminary Study of Their Hyoid Biomechanics in Healthy Adults

Purpose Deficiencies in swallowing (aspiration) and in maximum vocal pitch elevation have been shown to correlate in dysphagia. However, the underlying mechanisms that may explain this relationship are not known. In this study, we compare hyoid kinematics between swallowing and maximum vocal pitch elevation in healthy adults. Method Ten young (M = 21 ± 1.33 years) and eight older (M = 72.85 ± 5.59 years) healthy adults completed trials of maximum vocal pitch elevation (vowels /a/ and /i/) and swallowing (thin liquid and pudding) under videofluoroscopy. Superior and anterior hyoid excursions were obtained using kinematic analysis. Two-way analyses of variance and Spearman rho correlations were used to examine differences and relationships between swallowing and maximum pitch elevation biomechanics. Results Superior hyoid excursion was significantly greater for liquid swallows compared to pitch elevation tasks (/a/ and /i/; p = .002; Cohen's d = 1.28; p = .0179, Cohen's d = 1.03, respectively) and for pudding swallows compared to pitch tasks (p = .000, Cohen's d = 1.64; p = .001, Cohen's d = 1.38, respectively). Anterior hyoid excursion was not significantly different between the two functions, but was overall reduced in the older group (p = .0231, Cohen's d = .90). Furthermore, there was a moderate positive correlation between the degree of superior excursion during liquid swallows and maximum pitch elevation for both vowels (r s = .601, p = .001; r s = .524, p = .003) in young adults, and between the degree of anterior excursion during liquid swallows and pitch elevation for both vowels (r s = .688, p = .001; r s = .530, p = .008) in older adults. Conclusions Swallowing and maximum pitch elevation require similar anterior, but not superior, hyoid excursion in healthy adults. Differential correlations between the two tasks for each age group may be associated with age-related muscle changes. We provide evidence of partially shared biomechanics between swallowing and maximum pitch elevation.

Visuoperceptual Analysis of the Videofluoroscopic Study of Swallowing: An International Delphi Study

INTRODUCTION

The Videofluoroscopic Swallow Study (VFSS) is a commonly used dysphagia assessment that is routinely analysed visuoperceptually. However, no consensus exists regarding which visuoperceptual measures should be used to analyse VFSSs. Current visuoperceptual measures for VFSSs are limited by poor quality and incomplete or indeterminate psychometric properties.

OBJECTIVE

This study aimed to establish the content validity for a new visuoperceptual VFSS measure for oropharyngeal dysphagia in adults, by identifying relevant domains of the construct and generating items and corresponding response scales.

METHODS

Consensus among experts in dysphagia and VFSS from over 20 countries was achieved across three rounds of anonymous online surveys, using the Delphi technique. Participants judged relevance and comprehensiveness of definitions of visuoperceptual domains of VFSS and the relevance of various domains to the overall construct. After reaching consensus on definitions of relevant domains, consensus on items were established using the same process.

RESULTS

Participants achieved consensus on definitions of 32 domains recommended for analysis, and at least one item per domain (range 1-4). Domains selected by participants included both those which occur in existing measures and domains which have not been included in any measures to date. This study will form the basis for content validity of a new measure for VFSS.

CONCLUSIONS

This first phase of developing a visuoperceptual measure of VFSS resulted in the identification of 32 domains and 60 items for oropharyngeal dysphagia. Developers can now advance to the next phase of measure construction; prototype development and psychometric testing.

Endurance measurement of hyoid muscle activity and hyoid-laryngeal position during tongue lift movement

BACKGROUND

Tongue lift movement (TLM) is used as a therapy to improve tongue pressure against the hard palate for dysphagic patients.

OBJECTIVE

The present study aimed to characterize the time-dependent endurance changes in hyoid muscle activity and hyoid-laryngeal displacement during TLM in different ways.

METHODS

Sixteen young healthy volunteers were instructed to perform TLM at maximum effort (100%) against the anterior and posterior parts of the hard palate using a balloon-type tongue pressure instrument, followed by a 10-second recording during anterior 80% TLM, anterior 100% TLM, posterior 80% TLM and posterior 100% TLM with visual feedback. Electromyography (EMG) of suprahyoid (S-Hyo) and infrahyoid (I-Hyo) muscles and videofluorography were simultaneously recorded. To evaluate temporal changes, the recording period was divided into three substages: early, middle and late. Tongue pressure, integrated EMG (iEMG), power frequency of EMG burst and hyoid-laryngeal position were compared among the conditions (80% vs 100%, anterior vs posterior and early vs middle vs late).

RESULTS

Tongue pressure was stably maintained for 10 seconds in all conditions. S-Hyo iEMG and I-Hyo iEMG were significantly greater at 100% than at 80%, while no significant difference was observed between positions. S-Hyo iEMG and I-Hyo iEMG significantly increased at the late stage, while power frequency of EMG burst gradually decreased. Significant temporal changes in laryngeal elevation were observed only in posterior 100% TLM.

CONCLUSION

The current results suggested that isometric posterior TLM may be more useful compared with anterior TLM in clinical situations for dysphagic patients to elevate the hyolaryngeal complex.