The effects of simulated gastroesophageal reflux on infant pig oropharyngeal feeding physiology.

The neural connectivity among the oral cavity, pharynx, and esophagus is a critical component of infant feeding physiology. Central integration of oral and pharyngeal afferents alters motor outputs to structures that power swallowing, but the potential effects of esophageal afferents on preesophageal feeding physiology are unclear. These effects may explain the prevalence of oropharyngeal dysphagia in infants suffering from gastroesophageal reflux (GER), though the mechanism underlying this relationship remains unknown. Here we use the validated infant pig model to assess the impacts of simulated GER on preesophageal feeding parameters. We used high-speed videofluoroscopy and electromyography to record bottle-feeding before and following the infusion of a capsaicin-containing solution into the lower esophagus. Sucking parameters were minimally affected by capsaicin exposure, such that genioglossus activity was unchanged and tongue kinematics were largely unaffected. Aspects of the pharyngeal swallow were altered with simulated GER, including increased thyrohyoid muscle activity, increased excursions of the hyoid and thyroid per swallow, decreased swallow frequency, and increased bolus sizes. These results suggest that esophageal afferents can elicit changes in pharyngeal swallowing. In addition, decreased swallowing frequency may be the mechanism by which esophageal pathologies induce oropharyngeal dysphagia. Although recent work indicates that oral or pharyngeal capsaicin may improve dysphagia symptoms, the decreased performance following esophageal capsaicin exposure highlights the importance of designing sensory interventions based upon neurophysiology and the mechanisms underlying disordered feeding. This mechanistic approach requires comprehensive data collection across the entirety of the feeding process, which can be achieved using models such as the infant pig.NEW & NOTEWORTHY Simulated gastroesophageal reflux (GER) in an infant pig model resulted in significant changes in pharyngeal swallowing, which suggests that esophageal afferents are centrally integrated to alter motor outputs to the pharynx. In addition, decreased swallow frequency and increased bolus sizes may be underlying mechanisms by which esophageal pathologies induce oropharyngeal dysphagia. The infant pig model used here allows for a mechanistic approach, which can facilitate the design of intervention strategies based on neurophysiology.

Polysomnographic airflow shapes and site of collapse during drug-induced sleep endoscopy.

BACKGROUND: Differences in the pharyngeal site of collapse influence efficacy of non-continuous positive airway pressure therapies for obstructive sleep apnoea (OSA). Notably, complete concentric collapse at the level of the palate (CCCp) during drug-induced sleep endoscopy (DISE) is associated with reduced efficacy of hypoglossal nerve stimulation, but CCCp is currently not recognisable using polysomnography. Here we develop a means to estimate DISE-based site of collapse using overnight polysomnography. METHODS: 182 OSA patients provided DISE and polysomnography data. Six polysomnographic flow shape characteristics (mean during hypopnoeas) were identified as candidate predictors of CCCp (primary outcome variable, n=44/182), including inspiratory skewness and inspiratory scoopiness. Multivariable logistic regression combined the six characteristics to predict clear presence (n=22) versus absence (n=128) of CCCp (partial collapse and concurrent tongue base collapse excluded). Odds ratios for actual CCCp between predicted subgroups were quantified after cross-validation. Secondary analyses examined complete lateral wall, tongue base or epiglottis collapse. External validation was performed on a separate dataset (ntotal=466). RESULTS: CCCp was characterised by greater scoopiness (ß=1.5±0.6 per 2sd, multivariable estimate±se) and skewness (ß=11.4±2.4) compared with non-CCCp. The odds ratio for CCCp in predicted positive versus negative subgroups was 5.0 (95% CI 1.9-13.1). The same characteristics provided significant cross-validated prediction of lateral wall (OR 6.3, 95% CI 2.4-16.5), tongue base (OR 3.2, 95% CI 1.4-7.3) and epiglottis (OR 4.4, 95% CI 1.5-12.4) collapse. CCCp and lateral wall collapse shared similar characteristics (skewed, scoopy), diametrically opposed to tongue base and epiglottis collapse characteristics. External validation confirmed model prediction. CONCLUSIONS: The current study provides a means to recognise patients with likely CCCp or other DISE-based site of collapse categories using routine polysomnography. Since site of collapse influences therapeutic responses, polysomnographic airflow shape analysis could facilitate precision site-specific OSA interventions.

The effect of pharyngeal structures on the severity of obstructive sleep apnea.

BACKGROUND/OBJECTIVE: Obstructive sleep apnea (OSA) is characterized by complete or partial cessation of breathing during sleep. The tongue is suggested as a possible anatomical site causing airway obstruction. However, the role of other pharyngeal structures in the development of OSA remains unclear. We designed a study using both the apnea-hypopnea index (AHI) and the oxygen saturation measurements to assess the severity of OSA. We aimed to identify critical anatomical structures of the upper airway that correlate with the severity of OSA and to evaluate the utility of magnetic resonance imaging (MRI) markers to detect possible OSA in patients without overt symptoms. MATERIALS AND METHODS: The study included participants referred to the neurology outpatient clinic from the check-up unit. Participants were grouped as controls, mild, moderate, or severe OSA according to the AHI. A cranial MRI with a field of view (FOV) encompassing the upper airway structures was obtained from all participants. The areas of the tongue and the uvula were measured on the sagittal images by drawing the boundaries of the tissues manually. The posterior air space (PAS) area was evaluated from regions of interest in five parallel planes. RESULTS: Of 105 participants, 30 were controls, 27 had mild, 25 had moderate, and 23 had severe OSA. The moderate and severe OSA groups did not differ in oxygen saturation levels during sleep. Therefore, patients with moderate and severe OSA were combined into one group (moderate/severe OSA). The area of the tongue was significantly larger in the moderate/severe OSA group compared to the control group. Both the tongue and the uvula areas showed a significant positive correlation with the AHI. CONCLUSION: Our findings suggest that the tongue and uvula have prominent roles in the severity of OSAS. It may be useful to measure these structures with MRI to screen for at-risk individuals without overt OSA symptoms.

Swallowing improvement surgeries.

PURPOSE: To discuss the different swallowing improvement surgeries that address one or more dysfunctional pharyngolaryngeal structures causing dysphagia. These surgeries reduce the risk of aspiration without sacrificing vocal function. METHODS: We searched the PubMed database and used Google Scholar search engine to find studies discussing the different swallowing improvement surgeries. A manual search of references in selected articles and reviews was done as well. No chronologic limitation was set for the studies; however, only articles written in English and Japanese were considered. Due to the nature of this article, no particular inclusion or exclusion criteria were set when searching for studies to be used as references; however, all relevant studies were reviewed and agreed upon by the authors for inclusion in this review article. RESULTS/DISCUSSION: Surgeries to improve swallowing function can be categorized into those that reinforce nasopharyngeal closure or pharyngeal contraction, improve laryngeal elevation or pharyngoesophageal segment opening, and those that improve vocal fold closure to protect the airway during swallowing. They are an effective alternative treatment that may significantly improve these patients' quality of life. Swallowing rehabilitation with the altered pharyngolaryngeal structures is required post-operatively to significantly improve patients' dysphagia. CONCLUSIONS: Surgeries to improve swallowing function address specific dysfunctional sites involved in the swallowing mechanism. Choosing the most appropriate surgery for each patient requires knowledge of the pathophysiology for their dysphagia and detailed pre-operative work-up.

Ventilatory Drive Withdrawal Rather Than Reduced Genioglossus Compensation as a Mechanism of Obstructive Sleep Apnea in REM Sleep.

Rationale: REM sleep is associated with reduced ventilation and greater obstructive sleep apnea (OSA) severity than non-REM (nREM) sleep for reasons that have not been fully elucidated. Objectives: Here, we use direct physiological measurements to determine whether the pharyngeal compromise in REM sleep OSA is most consistent with 1) withdrawal of neural ventilatory drive or 2) deficits in pharyngeal pathophysiology per se (i.e., increased collapsibility and decreased muscle responsiveness). Methods: Sixty-three participants with OSA completed sleep studies with gold standard measurements of ventilatory "drive" (calibrated intraesophageal diaphragm EMG), ventilation (oronasal "ventilation"), and genioglossus EMG activity. Drive withdrawal was assessed by examining these measurements at nadir drive (first decile of drive within a stage). Pharyngeal physiology was assessed by examining collapsibility (lowered ventilation at eupneic drive) and responsiveness (ventilation-drive slope). Mixed-model analysis compared REM sleep with nREM sleep; sensitivity analysis examined phasic REM sleep. Measurements and Main Results: REM sleep (⩾10 min) was obtained in 25 patients. Compared with drive in nREM sleep, drive in REM sleep dipped to markedly lower nadir values (first decile, estimate [95% confidence interval], -21.8% [-31.2% to -12.4%] of eupnea; P < 0.0001), with an accompanying reduction in ventilation (-25.8% [-31.8% to -19.8%] of eupnea; P < 0.0001). However, there was no effect of REM sleep on collapsibility (ventilation at eupneic drive), baseline genioglossus EMG activity, or responsiveness. REM sleep was associated with increased OSA severity (+10.1 [1.8 to 19.8] events/h), but this association was not present after adjusting for nadir drive (+4.3 [-4.2 to 14.6] events/h). Drive withdrawal was exacerbated in phasic REM sleep. Conclusions: In patients with OSA, the pharyngeal compromise characteristic of REM sleep appears to be predominantly explained by ventilatory drive withdrawal rather than by preferential decrements in muscle activity or responsiveness. Preventing drive withdrawal may be the leading target for REM sleep OSA.

Non-REM Apnea and Hypopnea Duration Varies across Population Groups and Physiologic Traits.

Rationale: Symptoms and morbidities associated with obstructive sleep apnea (OSA) vary across individuals and are not predicted by the apnea-hypopnea index (AHI). Respiratory event duration is a heritable trait associated with mortality that may further characterize OSA.Objectives: We evaluated how hypopnea and apnea durations in non-REM (NREM) sleep vary across demographic groups and quantified their associations with physiological traits (loop gain, arousal threshold, circulatory delay, and pharyngeal collapsibility).Methods: Data were analyzed from 1,546 participants from the Multi-Ethnic Study of Atherosclerosis with an AHI ≥5. Physiological traits were derived using a validated model fit to the polysomnographic airflow signal. Multiple linear regression models were used to evaluate associations of event duration with demographic and physiological factors.Measurements and Main Results: Participants had a mean age ± SD of 68.9 ± 9.2 years, mean NREM hypopnea duration of 21.73 ± 5.60, and mean NREM apnea duration of 23.87 ± 7.44 seconds. In adjusted analyses, shorter events were associated with younger age, female sex, higher body mass index (P < 0.01, all), and Black race (P < 0.05). Longer events were associated with Asian race (P < 0.01). Shorter event durations were associated with lower circulatory delay (2.53 ± 0.13 s, P < 0.01), lower arousal threshold (1.39 ± 0.15 s, P < 0.01), reduced collapsibility (-0.71 ± 0.16 s, P < 0.01), and higher loop gain (-0.27 ± 0.11 s, P < 0.05) per SD change. Adjustment for physiological traits attenuated age, sex, and obesity associations and eliminated racial differences in event duration.Conclusions: Average event duration varies across population groups and provides information on ventilatory features and airway collapsibility not captured by the AHI.

Targeting the sensory feedback within the swallowing network-Reversing artificially induced pharyngolaryngeal hypesthesia by central and peripheral stimulation strategies.

Pharyngolaryngeal hypesthesia is a major reason for dysphagia in various neurological diseases. Emerging neuromodulation devices have shown potential to foster dysphagia rehabilitation, but the optimal treatment strategy is unknown. Because functional imaging studies are difficult to conduct in severely ill patients, we induced a virtual sensory lesion in healthy volunteers and evaluated the effects of central and peripheral neurostimulation techniques. In a sham-controlled intervention study with crossover design on 10 participants, we tested the potential of (peripheral) pharyngeal electrical stimulation (PES) and (central) transcranial direct current stimulation (tDCS) to revert the effects of lidocaine-induced pharyngolaryngeal hypesthesia on central sensorimotor processing. Changes were observed during pharyngeal air-pulse stimulation and voluntary swallowing applying magnetoencephalography before and after the interventions. PES induced a significant (p < .05) increase of activation during swallowing in the bihemispheric sensorimotor network in alpha and low gamma frequency ranges, peaking in the right premotor and left primary sensory area, respectively. With pneumatic stimulation, significant activation increase was found after PES in high gamma peaking in the left premotor area. Significant changes of brain activation after tDCS could neither be detected for pneumatic stimulation nor for swallowing. Due to the peripheral cause of dysphagia in this model, PES was able to revert the detrimental effects of reduced sensory input on central processing, whereas tDCS was not. Results may have implications for therapeutic decisions in the clinical context.

Modified Reflux Scintigraphy Detects Pulmonary Microaspiration in Severe Gastro-Esophageal and Laryngopharyngeal Reflux Disease.

INTRODUCTION: Previously described methodologies for detecting laryngopharyngeal reflux (LPR) have limitations. Symptoms alone are non-diagnostic, and pH-impedance studies have poor sensitivity. Pulmonary micro-aspiration is under-recognised in LPR and gastro-esophageal reflux disease (GERD). The present study aimed to describe the results of a modified technique for scintigraphic reflux studies in two groups with severe reflux: those with typical reflux symptoms and those with laryngopharyngeal manifestations of reflux. METHODS: A prospective database of severely symptomatic, treatment-resistant reflux patients was grouped based upon predominant symptom profile of typical GERD or LPR. All patients underwent reflux scintigraphy. Results were obtained for early scintigraphic reflux contamination of the pharynx and proximal esophagus, and delayed contamination of the pharynx and lungs after 2 h. RESULTS: 187 patients were studied (82 GERD, 105 LPR). The LPR patients were predominantly female (70.5% vs. 56.1%; p = 0.042) and older than the GERD group (median age 60 years vs. 55.5 years; p = 0.002). Early scintigraphic reflux was seen at the pharynx in 89.2% (GERD 87.7%, LPR 90.4%; p = 0.133), and at the proximal esophagus in 89.7% (GERD 88.9%, LPR 90.4%; p = 0.147). Delayed contamination of the pharynx was seen in 95.2% (GERD 93.9%, LPR 96.2%; p = 0.468). Delayed pulmonary aspiration was seen in 46% (GERD 36.6%, LPR 53.3%; p = 0.023). CONCLUSION: Reflux scintigraphy demonstrated a high rate of reflux-related pulmonary aspiration. Contamination of the proximal esophagus and pharynx was observed frequently in both groups of severe disease. The likelihood of pulmonary aspiration and potential pulmonary disease needs to be entertained in severe GERD and LPR.

Can the negative pressures found in obstructive sleep apnea and Eustachian tube dysfunction be related?

OBJECTIVE: The association between obstructive sleep apnea (OSA) and Eustachian tube dysfunction (ETD) is well known. When both exist in a single pediatric patient, one of the expected culprits is adenoid enlargement. We hypothesize, in contrast, that the negative pharyngeal pressure found in OSA may be transmitted to the middle ear as negative middle ear pressure (MEP), which subsequently results in pathology. The objective of this study was to determine whether the degree of OSA and MEP are associated while using MEP as a quantifiable measurement of ETD. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary academic center (Jan 2000-Jan 2018). SUBJECTS AND METHODS: The relationship between apnea-hypopnea index (AHI) and MEP was examined. A non-anatomic model was utilized to support causality. RESULTS: Thirty-four pediatric patients and twenty-three adult patients were included in the analysis. REM AHI showed a moderate negative correlation with MEP in children (r = -0.265), and a weak positive correlation with MEP in adults (r = 0.171). Children with an AHI in the severe OSA category had a more negative mean MEP than those in the mild category (p = 0.36). Adults with an AHI in the severe OSA category had a more positive mean MEP than those in the mild category (p = 0.11). CONCLUSION: In children, increasing severity of OSA is associated with a negative MEP, suggesting that negative pressure associated with OSA may be transmitted to the middle ear. In adults, increasing severity of OSA is associated with a more positive MEP.

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

INTRODUCTION/OBJECTIVE: The aim of this study is to analyze the influence of sour taste and cold temperature in the initiation of the pharyngeal swallow (IPS) and bolus location at pharyngeal swallow onset in individuals after stroke. METHODS: Cross-sectional prospective study. The study included 52 individuals with unilateral ischemic stroke. Each individual was assessed by videofluoroscopic swallowing study with 5ml of paste bolus offering four different stimuli (natural, cold, sour, and sour-cold). The individuals were divided into two groups according to the offer sequence. Group 1 (G1) - received a randomized sequence of stimuli (24 individuals), and Group 2 (G2) -the stimuli were offered in the following order: natural, cold, sour, and sour-cold(28 individuals). The IPS time and bolus location at pharyngeal swallow onset were analyzed. The bolus location at pharyngeal swallow onset was defined using six different levels. RESULTS: Individuals in G1 did not show a significant difference in IPS time between stimuli. However, individuals in G2 presented a significantly shorter IPS time with the sour and sour-cold stimuli than with natural or cold stimuli. The bolus location at pharyngeal swallow onset did not show significant difference between stimuli in both groups. On the other hand, in the G2 it was observed higher frequency of swallowing with sour-cold stimulus at level 1 (the bolus head was located in any region between the fauces pillar and the point where the tongue crosses the inferior border of the mandible). CONCLUSION: The sour and sour-cold stimuli influenced the IPS time when they were offered in a sequential order. Moreover, both the IPS time and bolus location at pharyngeal swallow onset were not influenced by the sour and sour cold-bolus when offered in a random sequence.

Endoscopic evaluation of pharyngeal and laryngeal sensation in patients with chronic obstructive pulmonary disease (COPD): A cross-sectional study.

OBJECTIVE: To describe and compare the findings of endoscopic sensory assessment in COPD patients and healthy controls. DESIGN: A prospective cross-sectional study. SETTING: Otorhinolaryngology outpatient clinic at a university hospital. PARTICIPANTS: 27 adults with COPD and 11 age-matched healthy controls. MAIN OUTCOME MEASURES: Group differences in light touch endoscopic tests of pharyngeal and laryngeal sensation, controlling for pooled salivary secretions in the pharynx and laryngo-pharyngeal reflux as measured by the Reflux Finding Score (RFS). RESULTS: A significant difference in laryngeal sensation was found between the study groups (P = .047), with reduced laryngeal sensation in the COPD patients. Additionally, a significant relationship was found between impaired oropharyngeal sensation and the presence of pooled salivary secretions in the pharynx (P = .018), especially in the pyriform sinuses (P = .012). No differences in the frequency of abnormal RFSs were found between groups. CONCLUSION: Individuals with COPD were significantly more likely to present with impaired laryngeal sensation. Additionally, impaired sensation in the oropharynx was associated with pooled salivary secretions in the pharynx.

Journey towards a personalised medicine approach for OSA: Can a similar approach to adult OSA be applied to paediatric OSA?

The concept of personalised medicine is likely to revolutionise the treatment of adult obstructive sleep apnoea as a result of recent advances in the understanding of disease heterogeneity by identifying clinical phenotypes, pathophysiological endotypes, biomarkers and treatable traits. Children with the condition show a similar level of heterogeneity and paediatric obstructive sleep apnoea would also benefit from a more targeted approach to diagnosis and management. This review aims to summarise the adult literature on the phenotypes and endotypes of obstructive sleep apnoea and assess whether a similar approach may also be suitable to guide the development of new diagnostic and management approaches for paediatric obstructive sleep apnoea.

Effects of transverse maxillomandibular distraction osteogenesis on obstructive sleep apnea syndrome and on the pharynx.

PURPOSE: To assess the effects of transverse maxillomandibular distraction osteogenesis (TMDO) on the treatment of obstructive sleep apnea (OSA) and on the morphology of the pharynx. METHODS: A clinical trial was conducted with seven patients with OSA and with transverse maxillomandibular deficiency, two women and five men aged on average 41.16 ± 10.9 years on the day of surgery. All participants were submitted to computed tomography (CT) and full-night polysomnography (PSG) before and approximately 9 months after surgery. A 95% confidence interval was defined. RESULTS: The AHI and RDI of the participants were reduced by about 62% (from 27.65 ± 36.65 to 10.73 ± 11.78, p = 0.031 and from 41.21 ± 32.73 to 15.30 ± 13.87, p = 0.015, respectively). The airway showed a surprising mean reduction in volume of 10% (from 5.78 ± 2.53 to 4.71 ± 1.42, p = 0.437, for the upper pharynx; from 6.98 ± 2.23 to 6.23 ± 2.05, p = 0.437, for the lower pharynx; and from 12.76 ± 1.56 to 10.94 ± 2.42, p = 0.625, for the total pharynx). However, the site of the smallest area of the pharynx was considerably increased both in the anteroposterior and transverse direction and in its total area (from 0.88 ± 7.11 to 0.99 ± 0.39, p = 0.625; from 1.78 ± 0.81 to 2.05 ± 0.61, p = 0.812; and from 0.99 ± 0.74 to 1.40 ± 0.51, p = 0.180, respectively). CONCLUSION: TMDO proved to be efficient in reducing or curing OSA, producing modifications of upper pharynx morphology with an increase of the smallest area of the pharynx.

Posterior Tongue Tie, Base of Tongue Movement, and Pharyngeal Dysphagia: What is the Connection?

Ankyloglossia, or tongue tie, and its impact on the oral phase of feeding has been studied and debated for decades. However, the impact of posterior tongue ties on the pharyngeal phase of swallowing is not well documented in the literature. A videofluoroscopic swallow study (VFSS) allows for visualization of the oral, pharyngeal, and esophageal phases of the swallow. When decreased base of tongue movement, impaired pharyngeal pressure generation, and presence of pharyngeal residue are noted during a VFSS, a neurologic etiology can be suspected. However, in the setting of a normal MRI with normal motor development, other etiologies need to be explored. If it is not neurologic, could it be anatomic? We present a 21-month-old patient with significant pharyngeal phase dysphagia which was most saliently characterized by impaired base of tongue movement, poor pressure generation, and diffuse residue resulting in aspiration. He was eventually diagnosed with a posterior tongue tie and underwent a frenulectomy. Results via subsequent VFSS revealed significant improvement in base of tongue movement, pharyngeal pressure generation, and pharyngeal constriction, resulting in efficient movement of the bolus through the pharynx into the esophagus, no nasopharyngeal regurgitation, no aspiration, and near resolution of his pharyngeal dysphagia. Patients with impaired base of tongue movement and impaired pressure generation resulting in pharyngeal residue in the setting of a normal neurologic workup could possibly present with a posterior tongue tie which should be examined and included in the differential diagnosis.

Pharyngeal Area Changes in Parkinson's Disease and Its Effect on Swallowing Safety, Efficiency, and Kinematics.

Pharyngeal area can increase as a function of normal healthy aging and muscle atrophy. These increases in pharyngeal area can negatively affect swallowing function in healthy older adults (HOA). However, the presence of pharyngeal area changes and their effects on swallowing function in Parkinson's disease (PD) remain unknown. Therefore, we compared the pharyngeal area of people with PD to HOA to determine if pharyngeal area changes were present in PD above and beyond what is seen in HOA. Within PD, we also evaluated if and how an increase in pharyngeal area affects swallowing kinematics, swallowing safety, and swallowing efficiency. A secondary analysis of videofluoroscopic swallow studies was completed comparing 41 HOA and 40 people with PD. Measures of pharyngeal area, swallowing kinematics, swallowing safety (penetration/aspiration), and swallowing efficiency (residue) were analyzed. An analysis of covariance (ANCOVA) was used to determine if pharyngeal area was significantly different between the HOA and PD groups while controlling for age, sex, and height. Regression analyses were used to examine if and how pharyngeal area influenced swallowing kinematics, swallowing safety, and swallowing efficiency in PD. Pharyngeal areas were significantly larger for people with PD when compared to HOA (p = .008). An increase in pharyngeal area was associated with less pharyngeal constriction (p = .022), shorter duration of airway closure (p = .017), worse swallowing safety (p < .0005), and worse swallowing efficiency (p = .037). This study revealed that pharyngeal areas are larger in people with PD when compared to HOA, and that this increase in pharyngeal area is associated with maladaptive changes to swallowing kinematics, residue, and penetration/aspiration. These findings support the notion that pharyngeal muscle atrophy may be exacerbated in PD above and beyond what is seen in normal, healthy aging group. Results from this study highlight the need to consider pharyngeal muscle atrophy as a source for swallowing dysfunction in PD, and as a potential treatment target for swallowing rehabilitation.

Pharyngeal Motility Before and After Thyroarytenoid Muscle Botulinum Toxin Injection.

Botulinum toxin type A (BTA) injection in intrinsic laryngeal musculature may result in dysphagia and consequent loss of quality of life (QOL) in a percentage of patients. This study aims to evaluate pharyngeal motility as a putative cause for this change in swallow quality in light of high-resolution manometry (HRM). Twenty patients (95% females, median age 66 years) underwent high-resolution manometry before and after BTA injection. Dysphagia was evaluated based on a QOL dedicated questionnaire (SWAL-QOL) before and after BTA injection. Pharyngeal motility at the topography of the vellum, epiglottis, and upper esophageal sphincter (UES) were recorded. Eleven (55%) subjects had worsened QOL after BTA injection. In patients with worsened QOL, UES extension decreased (p = 0.005), UES residual pressure increased (p = 0.02), UES basal pressure decreased (p = 0.04), and velopharynx contraction duration decreased (p = 0.04). UES residual pressure increased (p = 0.01), velopharynx peak pressure (p = 0.04) and upstroke (p = 0.007) decreased in patients with maintained QOL. There was no difference between groups when comparing pre-injection values. UES extension (p = 0.01) and UES maximum relaxation time (p = 0.03) was lower in the group with worsened QOL after BTA as compared to no change in QOL. Pharyngeal motility as measured by HRM was not a predictor for post procedure dysphagia and the changes in motility after BTA injection does not seem to be a strong contributor to dysphagia.

Temporal and Sequential Analysis of the Pharyngeal Phase of Swallowing in Poststroke Patients.

The purpose of this study was to conduct a quantitative analysis of the temporal and sequential events of the pharyngeal phase of swallowing in 45 poststroke patients who presented or did not present with supraglottic penetration and/or laryngotracheal aspiration and to compare the groups with each other and to a group of 46 patients with normal swallowing. All individuals were assessed by videofluoroscopy and the temporal and sequential measures for the swallowing of 3 mL and 5 mL of thickened liquid, 3 mL of liquid, and 3 mL and 5 mL of pasty were obtained by analyzing the recorded exams on Virtual Dub software. The following events were measured: time of maximal displacement and sustaining of the hyoid and larynx, duration of velopharyngeal sphincter (VS) and supraglottic closure, total inversion time of the epiglottis, duration of pharyngeal constriction, and duration of upper esophageal sphincter (UES) opening. For the analysis of the temporal sequence, the initial time of larynx and hyoid elevation, VS closure, epiglottic inversion, supraglottic closure, pharyngeal constriction, and opening of the UES were obtained. For 5 mL of thickened liquid, the maximum hyoid elevation time was greater for patients with normal swallowing and the time the supraglottis remained closed was higher in the aspirators group. The time of pharyngeal constriction during swallowing of 3 mL of thickened liquid was lower in the aspirators group. During the swallowing of 3 mL of thin liquid, it was observed that in the aspirators group, the larynx took longer to reach its maximum elevation and the epiglottis took longer to complete its total inversion. The analysis of the temporal sequence showed that patients in the aspirators group presented greater disorganization with significant alteration of the time interval between the events.

Optimizing the Translational Value of Mouse Models of ALS for Dysphagia Therapeutic Discovery.

The goal of this study was to compare dysphagia phenotypes in low and high copy number (LCN and HCN) transgenic superoxide dismutase 1 (SOD1) mouse models of ALS to accelerate the discovery of novel and effective treatments for dysphagia and early amyotrophic lateral sclerosis (ALS) diagnosis. Clinicopathological features of dysphagia were characterized in individual transgenic mice and age-matched controls utilizing videofluoroscopy in conjunction with postmortem assays of the tongue and hypoglossal nucleus. Quantitative PCR accurately differentiated HCN-SOD1 and LCN-SOD1 mice and nontransgenic controls. All HCN-SOD1 mice developed stereotypical paralysis in both hindlimbs. In contrast, LCN-SOD1 mice displayed wide variability in fore- and hindlimb involvement. Lick rate, swallow rate, inter-swallow interval, and pharyngeal transit time were significantly altered in both HCN-SOD1 and LCN-SOD1 mice compared to controls. Tongue weight, tongue dorsum surface area, total tongue length, and caudal tongue length were significantly reduced only in the LCN-SOD1 mice compared to age-matched controls. LCN-SOD1 mice with lower body weights had smaller/lighter weight tongues, and those with forelimb paralysis and slower lick rates died at a younger age. LCN-SOD1 mice had a 32% loss of hypoglossal neurons, which differed significantly when compared to age-matched control mice. These novel findings for LCN-SOD1 mice are congruent with reported dysphagia and associated tongue atrophy and hypoglossal nucleus pathology in human ALS patients, thus highlighting the translational potential of this mouse model in ALS research.

Association Between Pharyngeal Pooling and Aspiration Using Fiberoptic Endoscopic Evaluation of Swallowing in Head and Neck Cancer Patients with Dysphagia.

Postswallow pharyngeal pooling may be a risk factor for tracheal aspiration. However, limited literature shows the potential association between pharyngeal pooling and aspiration in head and neck cancer (HNC) patients. This study investigates the relationship between postswallow pharyngeal pooling and aspiration in HNC patients with oropharyngeal dysphagia. Furthermore, the effects of tumor stage, tumor location, and cancer treatment on aspiration were examined. Ninety dysphagic HNC patients underwent a standardized fiberoptic endoscopic evaluation of swallowing (FEES) using thin and thick liquid boluses. For each swallow, three visuoperceptual ordinal variables were scored: postswallow vallecular pooling, postswallow pyriform sinus pooling, and aspiration. Logistic regression analyses with correction for the location of pooling, tumor stage, tumor location, and cancer treatment were performed to explore the association between pooling and aspiration. No significant association was found between postswallow vallecular pooling and aspiration for thin liquid. However, severe versus mild-to-moderate postswallow vallecular pooling of thick liquid was significantly associated to aspiration. Similar results were seen after correction for the presence of pyriform sinus pooling, tumor stage, tumor location, or type of cancer treatment. This study showed a significant association between severe postswallow pyriform sinus pooling of thick liquid and aspiration, independent of the presence of vallecular pooling, tumor stage, tumor location, or cancer treatment. Concluding, location (valleculae versus pyriform sinuses), liquid bolus consistency (thin versus thick liquid), and amount of postswallow pharyngeal pooling (no pooling, mild/moderate pooling, severe pooling) have an influence on the probability of aspiration in dysphagic HNC patients, and they should be carefully considered during FEES, even in the absence of aspiration during the examination.

Airflow of the Two-Port Velopharyngeal Closure: Study Using Computational Fluid Dynamics.

Posterior pharyngeal flap palatoplasty is used to restore the function of velopharyngeal (VP) closure, after which 2 ports remain between the nasal and oral cavity. The authors hypothesized that the airflow dynamics of the upper airway is different in PPF patients compared to health subjects, who only has 1 movable port. Twenty adults who have multislice spiral computed tomography scan were included in this study. Two cylinders (radius, 2.00 mm; height, 4.5 mm) were used to recapitulate the 2-port VP structure after PPF palatoplasty. The areas of ports were modified by changing the radius of 2 cylinders. Real-time computational fluid dynamics simulation was used to capture the airflow velocity and pressures through the 2 ports. The airflow velocity and pressure of upper airway were recorded as the total areas of 2 VP ports increased. The total orifice areas of the 2-port VP closure for 4 VP conditions, including adequate closure, adequate/borderline closure, borderline/inadequate closure, and inadequate closure, were demonstrated. Significant differences between the 2-port VP function for demonstrating PPF reconstruction and the 1-port VP function were found. Airflow dynamics is dependent on the VP structure. The 2-port airflow model for mimicking VP closure after PPF palatoplasty demonstrated airflow characteristics that were significantly different from the 1-port model in normal VP closure.