Swallowing Time Research Articles

Normal values for swallow events during endoscopic evaluation of swallowing: a preliminary study.

The current investigation aimed to establish preliminary normative data for endoscopic swallow studies (FEES). The investigators collected data for three timing measures (time to whiteout, duration of whiteout, and total swallow time), three swallowing outcomes (safety, efficiency, and number of swallows per bolus), and one physiologic event (glottal response), for both healthy young and older adults using two liquid volumes, one pureed bolus and a solid bolus. Blinded raters retrospectively analyzed 65 randomly selected, deidentified videos of endoscopic swallowing examinations from a pool of 163 young and older adults with typical swallowing abilities. Timing measures and analysis of airway invasion, amount of residue, number of swallows, and glottal response were obtained. Preliminary means and quartiles were established for healthy adults in two age groups (young and old), for time to whiteout (WO), number of swallows per bolus, glottal response, Yale Residue Rating Scale Scores, Penetration-Aspiration Scale scores, duration of WO, and total swallow duration. Differences were found between the older and younger groups. The current study represents a preliminary attempt to provide quantitative and normative values for FEES. These data represent reference values to which other bolus presentations and populations can be compared. The data represents proof of concept and merits additional investigation. 1756246-2: Approved 2022/06/06. Study does not meet criteria. DATA REPOSITORY: https://doi.org/10.6084/m9.figshare.25800025 .

A Preliminary Study of Vallecular Bolus Aggregation in Healthy Swallowing of Solid Food Boluses.

The pharyngeal swallow typically begins within 400 ms following the arrival of a liquid bolus in the pharynx. By contrast, processed food particles aggregate in the valleculae prior to swallow initiation. With solid foods, swallow reaction time (SRT), the interval between bolus passing the ramus of mandible and hyoid burst onset (HYB) can be subdivided into components of vallecular aggregation time (VAT) and the subsequent end of aggregation to hyoid burst interval (EOA-to-HYB). However, expected durations of these timing measures remain unclear. We aimed to study bolus aggregation in healthy swallowing for International Dysphagia Diet Standardisation Initiative Food Levels 5 (minced and moist [MM5]), 6 (soft and bite-sized [SB6]), and 7 (regular [RG7]). Understanding typical patterns and durations of vallecular aggregation with solids in healthy swallowing will inform the identification of impaired swallow timing in patient populations. Twenty healthy adults (10 males, Mage = 28 years, range: 23-55 years) swallowed two boluses each of MM5, SB6, and RG7 foods in videofluoroscopy. Blinded duplicate ratings determined bolus location at swallow onset, SRT, VAT, and EOA-to-HYB. Texture-based differences were measured using Friedman's tests. Bolus location was at/above the valleculae at swallow onset for 85% of boluses, with no differences by texture. SRT, VAT, and EOA-to-HYB did not vary by texture, with overall median values (interquartile range) of 99 ms (-66 to 743 ms) for SRT, 347 ms (66 to 891 ms) for VAT, and -132 ms (-231 to -83 ms) for EOA-to-HYB. These data corroborate prior evidence that it is not unusual for food particles to aggregate in the valleculae prior to swallow initiation in healthy swallowing. However, durations of vallecular aggregation are typically < 1 s in healthy adults.

Association between swallowing dynamics, tongue pressure and pulmonary function in patients with idiopathic pulmonary fibrosis

BackgroundSwallowing is a complex process that requires the coordination of muscles in the mouth, pharynx, larynx, and esophagus. Dysphagia occurs when a person has difficulty swallowing. In the case of subjects with respiratory diseases, the presence of oropharyngeal dysphagia potentially increases lung disease exacerbations, which can lead to a rapid decline in lung function. This study aimed to analyze the swallowing of patients with idiopathic pulmonary fibrosis (IPF).MethodsPatients with IPF were evaluated using the Eating Assessment Tool (EAT-10), tongue pressure, the Timed Water Swallow Test (TWST), and the Test of Mastication and Swallowing Solids (TOMASS). The findings were related to dyspnea severity assessed by the modified Medical Research Counsil (mMRC) score; the nutritional status screened with Mini Nutritional Assessment (MNA) tool; and pulmonary function tests, specifically spirometry and measurement of the diffusing capacity for carbon monoxide (DLCO), the maximal inspiratory pressure (PImax), and the maximal expiratory pressure (PEmax).ResultsThe sample consisted of 34 individuals with IPF. Those who exhibited swallowing modifications scored lower on the MNA than those who did not (9.6 ± 0.76 vs. 11.64 ± 0.41 points; mean difference 1.98 ± 0.81 points; p = 0.02). They also showed poorer lung function when considering the predicted force vital capacity (FVC; 81.5% ± 4.61% vs. 61.87% ± 8.48%; mean difference 19.63% ± 9.02%; p = 0.03). The speed of liquid swallowing was altered in 31of 34 of the evaluated subjects (91.1%). The number of liquid swallows correlated significantly with the forced expiratory volume in 1 s (FEV1)/FVC ratio (r = 0.3; p = 0.02). Solid eating and swallowing assessed with the TOMASS score correlated with lung function. The number of chewing cycles correlated negatively with PImax% predicted (r = -0.4; p = 0.0008) and PEmax% predicted (r = -0.3; p = 0.02). FVC% predicted correlated with increased solid swallowing time (r = -0.3; p = 0.02; power = 0.6). Swallowing solids was also impacted by dyspnea.ConclusionPatients with mild-to-moderate IPF can present feeding adaptations, which can be related to the nutritional status, lung function, and the severity of dyspnea.

Swallowing rehabilitation of patients undergoing T-tube implantation for the treatment of laryngotracheal stenosis.

Patients with laryngotracheal stenosis (LTS) often have dysphagia after laryngotracheal reconstruction with T-tube insertion, which affects the quality of life. The purpose of this study is to observe the effect of swallowing rehabilitation therapy on the improvement of quality of life in patients of otolaryngology-head and neck surgery with dysphagia undergoing T-tube implantation treatment through longitudinal study. Thirty-eight patients with LTS who experienced dysphagia after laryngotracheal reconstruction and T-tube implantation were recruited. All patients received swallowing rehabilitation therapy. The assessment of swallowing function was performed using the 10-item Eating Assessment Tool (EAT-10), the 30 mL water swallow test (WST), and flexible endoscopic evaluation of swallow (FEES). After swallowing rehabilitation therapy, timing of swallowing, grade of dysphagia, performance on FEES and 30 mL WST, and EAT-10 score all improved. Thirty-eight patients successfully transitioned to oral feeding and were able to remove their nasogastric tubes without experiencing any complications, including aspiration pneumonia. For patients with LTS who experienced dysphagia after laryngotracheal reconstruction and T-tube implantation, swallowing rehabilitation therapy could improve swallowing function of the patients, so as to reduce the potential harm caused by the pain and complications of surgery experienced by patients.

Assessing the oral and suprahyoid muscles in healthy adults using muscle ultrasound to inform the swallowing process: a proof-of-concept study

The oral and suprahyoid muscles are responsible for movements of swallowing. Our study aimed to determine the reproducibility of static and dynamic measurements of these muscles using bedside ultrasound equipment. Forty healthy participants were recruited prospectively. Primary outcomes were evaluation of mass measurements of the anterior bellies of the digastric, mylohyoid, geniohyoid and tongue in B-mode ultrasound. Secondary outcomes were evaluation of geniohyoid muscle layer thickness and function using M-mode. Muscle mass measurements demonstrated little within-participant variability. Coefficient of Variance (CoV) across muscles were: anterior belly digastric (5.0%), mylohyoid (8.7%), geniohyoid (5.0%) and tongue (3.2%). A relationship between sex (r2 = 0.131 p = 0.022) was demonstrated for the geniohyoid muscle, with males having higher transverse Cross Sectional Area (CSA) (14.3 ± 3.6 mm vs. 11.9 ± 2.5 mm, p = 0.002). Tongue size was correlated with weight (r2 = 0.356, p = 0.001), height (r2 = 0.156, p = 0.012) and sex (r2 = 0.196, p = 0.004). Resting thickness of the geniohyoid muscle layer changed with increasing bolus sizes (f = 3.898, p = 0.026). Velocity increased with bolus size (p = < 0.001, F = 8.974). However swallow time and slope distance did not, potentially influenced by higher coefficients of variation. Oral and suprahyoid muscle mass are easily assessed using bedside ultrasound. Ultrasound may provide new information about muscle mass and function during swallowing.

Test of mastication and swallowing solids in healthy individuals aged 6 to 20 years: A normative study in an Indian context.

The Test of Mastication and Swallowing Solids (TOMASS) is a reliable tool for assessing chewing and swallowing in healthy adults, using commercially available crackers. TOMASS-Children (TOMASS-C) is the paediatric version of TOMASS. The present study aimed to establish normative data for TOMASS-C using a validated regional commercial cracker among healthy individuals aged between 6-20 years of India. 327 healthy individuals between 6-20 years were recruited in a cross-sectional study design following a convenient sampling procedure. Participants consumed one validated regional cracker and the procedure was video recorded. Data were stratified according to age groups (6-7, 8-9, 10-13, 14-17 and 18-20 years) and sex (boys and girls). Two Speech Language Pathologists independently analysed the video recordings to derive discrete bites, masticatory cycles, swallows and total swallow time indices. Using them, time/swallow, masticatory cycles/bite, swallows/bite and time/bite were calculated. All parameters of TOMASS-C had moderate to good (0.6-0.85) test-retest reliability and moderate to excellent (0.69-0.99) inter-rater reliability at p > .000. Younger participants took more bites, chewed more times and swallowed more frequently with longer chewing and swallowing time. Boys exhibited a lower number of swallows, shorter swallow time and reduced total masticatory time at p > .05. Additionally, girls demonstrated fewer bites and chewing cycles compared to boys at p > .05. TOMASS-C using a validated regional cracker was feasible and reliable. Normative data established for healthy boys and girls between 6-20 years offers much-needed quantitative data to objectively delineate individuals with and without chewing and swallowing solid food difficulties.

Effortful Swallow Maneuver and Modifications on Swallow Dynamics in Healthy Adults

Introduction: Effortful swallow (ES) is a widely used technique in dysphagia management, believed to strengthen oropharyngeal muscles and enhance swallowing safety and efficiency. Although its impact on the oral phase of swallowing is well documented, its effects on pharyngeal swallowing physiology remain inconsistent. This study aimed to elucidate the effects of ES on swallowing kinematics and timing, addressing existing inconsistencies in the literature. Methods: This study involved 22 healthy adults using archived videofluoroscopic swallowing studies. Participants performed three swallow trials of 10 mL puree under regular conditions and with the ES maneuver. The outcome measures comprised swallow timing and kinematic measures. Swallow timing parameters included time to maximum hyoid and laryngeal excursion, laryngeal vestibule closure (LVC) reaction and duration, pharyngeal constriction duration, pharyngoesophageal segment (PES) opening duration, and swallow duration. Swallow kinematic parameters encompassed hyoid and laryngeal excursions, pharyngeal constriction ratio, and maximum PES width. All variables were analyzed via videofluoroscopy. Paired t tests were used to examine the effect of ES on each outcome measure, with a significance threshold set at p < 0.004. Results: The ES maneuver significantly increased the duration of LVC, pharyngeal constriction, PES opening, and overall swallow duration. It also improved the pharyngeal constriction ratio. However, there were no significant changes in hyoid and laryngeal excursions. Submental muscle activity showed a notable increase during ES. Conclusion: The study demonstrates that ES can effectively modify certain temporal and kinematic aspects of swallowing, particularly by prolonging key phases and enhancing pharyngeal constriction. These findings suggest the potential utility of ES in dysphagia rehabilitation, especially in cases that require prolonged pharyngeal constriction, LVC, and PES opening. However, the limited impact on hyoid and laryngeal excursions along with LVC reaction time indicates that ES may not address all aspects of dysphagia. The findings highlight the need for tailored therapeutic approaches in dysphagia management, considering individual physiological impairment profiles.

Screening performance of a 100-mL water swallowing test in community-dwelling older adults: A receiver operating characteristic analysis.

The development of a dysphagia screening test is an urgent issue in the field of frailty prevention among community-dwelling older people. The purpose of this study was to evaluate the screening performance of a 100-mL water swallowing test (WST). The study employed a cross-sectional design. Participants were 304 (65 men and 239 women, mean age = 80 years) Japanese community-dwelling older adults aged over 65 years. We investigated swallowing disorder using the 10-item Eating Assessment Tool (EAT-10), and compared choking signs, swallowing time and number of swallows, and their combination in the 100-mL WST. We calculated the sensitivity and specificity of these indices. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cut-off value of swallowing time and number of swallows in the 100-mL WST based on the Youden Index among participants without choking signs. The sensitivity and specificity of choking signs in the 100-mL WST were 20% and 91%, respectively. The discriminating ability of swallowing time and number of swallows among participants without any choking signs was .76 and .72, respectively, in the area under the ROC curve. Diagnostic sensitivity and specificity to discriminate dysphagia from normal swallowing ability were 65% and 74% when the cut-off was >10 s based on maximisation of the Youden Index. The 100-mL WST performed best when the indices of choking signs and swallowing time were combined, with a sensitivity and specificity of 72% and 68%, respectively. The 100-mL WST would be an adequate screening tool when compared to the EAT-10.

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.

Virological Non-Suppression, Non-Adherence and the Associated Factors Among People Living with HIV on Dolutegravir-Based Regimens: A Retrospective Cohort Study.

HIV is one of the leading causes of morbidity and mortality, with 39.0 million people living with HIV worldwide, 25.6 million of whom reside in the African region. Highly active anti-retroviral therapy (HAART) has improved survival and quality of life, yet some patients develop viral non-suppression. Dolutegravir (DTG) has been recommended since 2018 as a first-line treatment option in low- and middle-income countries owing to its effectiveness, low cost, and tolerability, but some studies have reported virological non-suppression with its use. This study aims to explore the prevalence and factors associated with virological non-suppression in adults taking DTG-based regimens in Mbarara Regional Referral Hospital. A retrospective cohort study was carried out among people living with HIV (PLWHIV) taking DTG-based HAART regimens by way of record review. SPSS was used for analysis, and both binary and multivariate logistic regression analyses were performed to test associated factors. Among the 422 participants' records reviewed, 62.8% were female (median age 40 years, IQR=13). The prevalence of virological non-suppression was 4.2%. Poor adherence to HAART was significantly associated with virological non-suppression, with 100.3 increased adjusted odds (95% CI: 28.90-348.12, p<0.001) compared to those with a record of good adherence. The reasons for poor adherence included alcohol use, stigma, forgetting to take medication, transport problems, and irregular timing of swallowing. This study found poor adherence to be associated with a 4.2% prevalence of virological non-suppression among PLWHIV in a large public HIV care clinic. Despite the high suppression rates on DTG-based regimens, adherence counseling and viral load monitoring need to be emphasized at all HIV care centers to mark the trends of virological non-suppression.

Videofluoroscopic measures of swallowing in people with stable COPD compared to healthy aging.

Swallowing impairment is a serious extra-pulmonary manifestation of Chronic Obstructive Pulmonary Disease (COPD). Previous studies suggest that individuals with stable COPD show atypical values for several videofluoroscopy measures of swallowing, compared to healthy adults under age 60. However, it is unclear to what degree these changes are attributable to healthy aging. In this study, we aimed to clarify how swallowing in people with stable COPD differs from age-matched healthy controls. We performed a retrospective analysis of videofluoroscopy data from two previously-collected datasets: a) a sample of 28 adults with stable COPD (18 male); b) a sample of 76 healthy adults, from which 28 adults were selected, matched for sex and age to participants in the COPD cohort. In both prior studies, participants swallowed 20% w/v liquid barium prepared in different consistencies (thin; mildly, moderately, and extremely thick). Blinded duplicate ratings were performed according to a standard procedure, yielding measures of laryngeal vestibule closure (LVC) integrity and timing, swallow timing, upper esophageal sphincter (UES) opening, pharyngeal constriction and pharyngeal residue. Mann-Whitney U tests and odds ratios were performed to determine significant group differences (p<.05). Across the consistencies tested, participants with COPD showed significantly shorter durations of LVC, earlier onsets and shorter durations of UES opening, and reduced pharyngeal constriction. No significant differences were seen in other measures. These results point to features of swallowing in people with stable COPD that differ from changes seen with healthy aging, and which represent risks for potential aspiration.

Impact of Varying Transcutaneous Electrical Stimulation Pulse Frequency on Swallow Timing Measures in Healthy Adults.

The impaired swallow timing subsequent to dysphagia or aging can potentially endanger swallowing safety and efficiency. Preliminary evidence has suggested that transcutaneous electrical stimulation (TES) may have the potential to affect swallow timing. However, limited knowledge exists regarding which TES parameters can optimize swallow timing. Pulse frequency is one of the primary TES parameters that can affect the quality of muscle contraction. Yet, no clear information exists regarding how changing pulse frequency impacts the timing of swallowing events. This study aimed to investigate the varying effects of submental TES pulse frequency on swallowing events during and post-15-min TES administration. Twenty-six healthy individuals between the ages of 20 and 54 participated in this study and were assigned to high pulse frequency (HPF) (80 Hz) or low pulse frequency (LPF) (30 Hz) groups. Videofluoroscopic swallowing study (VFSS) was used to record swallowing. Three trials of 10mL pureed mixed with barium sulfate were presented under three different conditions, including pre-TES, during TES, and post-TES, in which measures were taken following 15min of TES delivery. The swallow timing events that were measured in each condition were time to maximum hyoid elevation, time to maximum laryngeal elevation, laryngeal vestibule closure reaction time (LVCrt), laryngeal vestibule closure duration (LVCd), time to maximum pharyngeal constriction, and pharyngoesophageal segment (PES) opening duration. No significant pulse frequency effect was found on any swallow timing measures during or after 15min of TES. Both protocols decreased the duration of some swallowing events during TES including time to maximum hyoid elevation [p < 0.017, ηp2 = 0.185], LVCrt [p < 0.032, ηp2 = 0.158], and time to maximum pharyngeal constriction [p < 0.034, ηp2 = 0.155]. None of the significant TES effects were continued when TES ceased after 15min. Overall, both protocols have comparable immediate effects on shortening the duration of some swallowing events during TES. Future clinical trials should examine whether these physiologic timing changes can lead to safer and more efficient swallows in patients with dysphagia.

Oral-Motor Function in older people: Exploring new dimensions of frailty.

Oral-motor performance for speech and swallowing, and verbal fluency represent important domains that can determine frailty thresholds in older people. The study aims to explore the association between oral-motor performance and verbal fluency to achieve a comprehensive measurement of the frailty phenotype. An exploratory and inferential cross-sectional study was carried out in two nursing homes and two day-care centers. The study comprised a sample of 95 individuals with a mean age of 83 years. The Oral-Diadochokinesis Test (ODDK), Water Swallow Test (WST), Time of Mastication and Swallowing (TOMASS), Maximum Tongue Pressure, Verbal Fluency, Physical Phenotype and Mini-Mental State Examination (MMSE) were used as measurements variables. The comparison of mean values between the performance of observed and normative values for the target population was shown to be statistically significant for all the measurements and between the pre-frail and frail. The results of this study add to the growing body of evidence that oral-motor function for speech and swallowing and verbal fluency are relevant to the diagnosis and management of the frailty condition in older people. The frailty syndrome is more than just the traditionally observed physical function, rather it is a multidimensional construct, where additional dimensions should be considered when evaluating frailty in clinical practice.

Paediatric solid oral dosage forms for combination products: Improving in vitro swallowability of minitablets using binary mixtures with pellets

There is a growing interest in enhancing the acceptability of paediatric pharmaceutical formulations. Solid oral dosage forms (SODF), especially multiparticulates, are being considered as an alternative to liquid formulations, but they may compromise palatability when large volumes are required for dosing. We hypothesised that a binary mixture of multiparticulates for paediatric use, designed to increase the formulation maximum packing fraction, could reduce the viscosity of the mixture in soft food and facilitate swallowing.Using the Paediatric Soft Robotic Tongue (PSRT) – an in vitro device inspired by the anatomy and physiology of 2-year-old children – we investigated the oral phase of swallowing for multi-particulate formulations, i.e., pellets (350 and 700 µm particles), minitablets (MTs, 1.8 mm), and their binary mixtures (BM), by evaluating oral swallowing time, the percentage of particles swallowed, and post-swallow residues. We also conducted a systematic analysis of the effect of the administration method, bolus volume, carrier type, particle size, and particle volume fraction on pellets swallowability.The results demonstrated that the introduction of pellets affected the flowing ability of the carriers, increasing shear viscosity. The size of the pellets did not appear to influence particle swallowability but raising the particle volume fraction (v.f.) above 10% resulted in a decrease in the percentage of particles swallowed. At v.f. 0.4, pellets were easier to swallow (+ 13.1%) than MTs, being the administration method used highly dependent on the characteristics of the multi-particulate formulation under consideration. Finally, mixing MTs with only 24% of pellets improved particle swallowability, achieving swallowing levels similar to those of pellets alone. Thus, combining SODF, i.e., MTs and pellets, improves MT swallowability, and offers new possibilities for adjusting product palatability, being particularly attractive for combination products.

The relationship between manometric subtype and symptom details in achalasia.

Although dysphagia and chest pain are the two most common symptoms in patients with achalasia, the mechanism of evoking symptoms is still unknown. The aim of this study was to reveal the relationship between symptoms and the subtypes of achalasia defined by the Chicago classification. A total of 71consecutive patients with newly diagnosed achalasia were enrolled between March 2009 and December 2017. Esophageal motility was assessed by high-resolution manometry (HRM) with the Chicago classification v 3.0. and esophagograms. Their symptoms were evaluated with structured self-reported questionnaires focused on dysphagia and chest pain. Symptom profiles and radiographic findings according to the manometric subtypes were investigated. Among the total 71 patients, 69 patients (97%) had dysphagia and 39 patients (54%) had chest pain. Regarding dysphagia, type II patients reported dysphagia in the throat the most, while types I and III patients mostly felt it in the epigastrium. Type II patients often felt dysphagia at the time of swallowing (41%), but this was reported in only 8.7% of Type I and 33% of Type III patients (p = 0.02). Concerning chest pain, Type I patients rarely had pain during meals (14%), but more often while sleeping (43%) and in early morning (43%), while type III patients often had pain during meals (67%). Type III patients reported that solid food caused pain more often than other types (I/II/III 0/10/33%, p = 0.09). Detailed symptoms of achalasia, such as its site and timing, varied by subtypes. The status of the esophageal body might induce those differences in symptoms.

Swallowing disorder – A possible therapeutic target for preventing COPD exacerbations

Dysphagia is a common comorbidity of chronic obstructive pulmonary disease (COPD). In this review article, we show that swallowing disorder can be detected at its early stage as a manifestation of breathing-swallowing discoordination. Furthermore, we provide evidence that low-pressure continuous airway pressure (CPAP) and transcutaneous electrical sensory stimulation using interferential current (IFC-TESS) counteract swallowing disorders and may reduce exacerbations in patients with COPD. Our first prospective study showed that inspiration immediately before or after swallowing is associated with COPD exacerbation. However, the inspiration before swallowing (I-SW) pattern could be interpreted as an airway-protecting behavior. Indeed, the second prospective study showed that the I-SW pattern is more frequently observed in patients who did not experience exacerbations. As potential therapeutic candidates, CPAP normalizes the timing of swallowing, and IFC-TESS applied to the neck acutely facilitates swallowing and chronically improves nutrition and airway protection. Further studies are necessary to elucidate whether such interventions reduce exacerbations in patients with COPD.

Quantifying long-term phenological patterns of aerial insectivores roosting in the Great Lakes region using weather surveillance radar.

Organisms have been shifting their timing of life history events (phenology) in response to changes in the emergence of resources induced by climate change. Yet understanding these patterns at large scales and across long time series is often challenging. Here we used the US weather surveillance radar network to collect data on the timing of communal swallow and martin roosts and evaluate the scale of phenological shifts and its potential association with temperature. The discrete morning departures of these aggregated aerial insectivores from ground-based roosting locations are detected by radars around sunrise. For the first time, we applied a machine learning algorithm to automatically detect and track these large-scale behaviors. We used 21 years of data from 12 weather surveillance radar stations in the Great Lakes region to quantify the phenology in roosting behavior of aerial insectivores at three spatial levels: local roost cluster, radar station, and across the Great Lakes region. We show that their peak roosting activity timing has advanced by 2.26 days per decade at the regional scale. Similar signals of advancement were found at the station scale, but not at the local roost cluster scale. Air temperature trends in the Great Lakes region during the active roosting period were predictive of later stages of roosting phenology trends (75% and 90% passage dates). Our study represents one of the longest-term broad-scale phenology examinations of avian aerial insectivore species responding to environmental change and provides a stepping stone for examining potential phenological mismatches across trophic levels at broad spatial scales.

RANDOMIZED COMPARATIVE STUDY OF THE USE OF AZITHROMYCIN AND IBUPROFEN IN PAIN AND POSTADENOTONSILLECTOMY COMORBIDITIES DURING CHILDHOOD

Introduction: The adenotonsillectomy is among the most usual surgical procedures during childhood. Postoperative pain in this type of surgery may be intense and long-lasting. It is a major obstacle against the return to the reasonable feeding condition because it makes swallowing more difficult. The nonsteroidal anti-inflammatory drugs (NSAIDs) are the most used group of medications for the treatment of acute pain, as they are considered safe, also due to their low cost and because they do not need any unique prescription. Azithromycin is an antibiotic of the macrolide group that can not only act as antimicrobial, but also as an anti-inflammatory. It has been observed that the macrolide drugs lower the production of cytokines, stimulate degranulation of the leucocytes, gather neutrophil and blood flow cells exposed to bacteria, and also accelerate the apoptosis of the leucocytes, which are typical effects of classical anti-inflammatory drugs. Objective: Aiming to assess these effects, a randomized comparative study in two groups of children undergoing adenotonsillectomy was performed. Material and Methods: Group 1 received ibuprofen in the postoperative, and group 2 received ibuprofen and azithromycin. Both groups were assessed as to immediate postoperative pain, at the moment of hospital discharge (4 to 6 hours after the surgery), on the 5th, 10th, and 14th postoperative day. The number of doses administered against pain, discomfort at the time of swallowing, and return to feeding, as well as postoperative comorbidities (fever, nausea, vomiting, and bleeding) were also observed. Results: The results did not show statistical significance between the groups. Conclusion: It was concluded that azithromycin did not lower postoperative pain; it does not make swallowing easier, and does not act over the comorbidities. More detailed studies must be made to better evaluate the effect of azithromycin as an anti-inflammatory in the adenotonsillectomy postoperative.

Optogenetic stimulation of pre–Bötzinger complex reveals novel circuit interactions in swallowing–breathing coordination

The coordination of swallowing with breathing, in particular inspiration, is essential for homeostasis in most organisms. While much has been learned about the neuronal network critical for inspiration in mammals, the pre-Bötzinger complex (preBötC), little is known about how this network interacts with swallowing. Here we activate within the preBötC excitatory neurons (defined as Vglut2 and Sst neurons) and inhibitory neurons (defined as Vgat neurons) and inhibit and activate neurons defined by the transcription factor Dbx1 to gain an understanding of the coordination between the preBötC and swallow behavior. We found that stimulating inhibitory preBötC neurons did not mimic the premature shutdown of inspiratory activity caused by water swallows, suggesting that swallow-induced suppression of inspiratory activity is not directly mediated by the inhibitory neurons in the preBötC. By contrast, stimulation of preBötC Dbx1 neurons delayed laryngeal closure of the swallow sequence. Inhibition of Dbx1 neurons increased laryngeal closure duration and stimulation of Sst neurons pushed swallow occurrence to later in the respiratory cycle, suggesting that excitatory neurons from the preBötC connect to the laryngeal motoneurons and contribute to the timing of swallowing. Interestingly, the delayed swallow sequence was also caused by chronic intermittent hypoxia (CIH), a model for sleep apnea, which is 1) known to destabilize inspiratory activity and 2) associated with dysphagia. This delay was not present when inhibiting Dbx1 neurons. We propose that a stable preBötC is essential for normal swallow pattern generation and disruption may contribute to the dysphagia seen in obstructive sleep apnea.

A Strength Endurance Exercise Paradigm Mitigates Deficits in Hypoglossal-Tongue Axis Function, Strength, and Structure in a Rodent Model of Hypoglossal Motor Neuron Degeneration.

The tongue plays a crucial role in the swallowing process, and impairment can lead to dysphagia, particularly in motor neuron diseases (MNDs) resulting in hypoglossal-tongue axis degeneration (e.g., amyotrophic lateral sclerosis and progressive bulbar palsy). This study utilized our previously established inducible rodent model of dysphagia due to targeted degeneration of the hypoglossal-tongue axis. This model was created by injecting cholera toxin B conjugated to saporin (CTB-SAP) into the genioglossus muscle of the tongue base for retrograde transport to the hypoglossal (XII) nucleus via the hypoglossal nerve, which provides the sole motor control of the tongue. Our goal was to investigate the effect of high-repetition/low-resistance tongue exercise on tongue function, strength, and structure in four groups of male rats: (1) control + sham exercise (n = 13); (2) control + exercise (n = 10); (3) CTB-SAP + sham exercise (n = 13); and (4) CTB-SAP + exercise (n = 12). For each group, a custom spout with adjustable lick force requirement for fluid access was placed in the home cage overnight on days 4 and 6 post-tongue injection. For the two sham exercise groups, the lick force requirement was negligible. For the two exercise groups, the lick force requirement was set to ∼40% greater than the maximum voluntary lick force for individual rats. Following exercise exposure, we evaluated the effect on hypoglossal-tongue axis function (via videofluoroscopy), strength (via force-lickometer), and structure [via Magnetic Resonance Imaging (MRI) of the brainstem and tongue in a subset of rats]. Results showed that sham-exercised CTB-SAP rats had significant deficits in lick rate, swallow timing, and lick force. In exercised CTB-SAP rats, lick rate and lick force were preserved; however, swallow timing deficits persisted. MRI revealed corresponding degenerative changes in the hypoglossal-tongue axis that were mitigated by tongue exercise. These collective findings suggest that high-repetition/low-resistance tongue exercise in our model is a safe and effective treatment to prevent/diminish signs of hypoglossal-tongue axis degeneration. The next step is to leverage our rat model to optimize exercise dosing parameters and investigate corresponding treatment mechanisms of action for future translation to MND clinical trials.