Post-swallow Residue Research Articles

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

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

Effect of the rheological properties of the liquid carrier on the in vitro swallowing of solid oral dosage forms

Solid oral dosage forms (SODF) are the most popular oral drug delivery forms, but they can be difficult to swallow, especially for patients suffering from swallowing disorders. This study investigated the dynamics of different combinations of liquid carriers and SODF during the oral phase of swallowing using an in vitro model. The rheological properties of the carriers were characterized using shear and extensional rheometry, and their effect on bolus velocity, bolus shape, post-swallow residues, and SODF position within the bolus was evaluated. The latter has been identified as a novel and promising variable to discriminate between alternative formulations. When swallowed with water, capsules and tablets did not impact significantly the velocity of the bolus, but they lagged behind the liquid bolus, suggesting that low viscosity Newtonian fluids are not efficient carriers for SODF. Increasing the viscosity of the carrier at high shear rates improved the ability of the liquid to transport the SODF but also increased the amount of post-swallow residues. At equivalent shear viscosity, elastic and extensional properties of carriers influenced positively the position of the SODF in the bolus. Capsules and tablets were transported toward the front of these boluses, during the oral phase of swallowing, which is considered beneficial to avoid SODF sticking to the mucosa in the following stages of swallowing. Thin elastic liquids appear as an interesting option to promote safe swallowing of capsules and tablets. Clinical studies are, however, necessary to confirm this positive effect in healthy and dysphagic patients.

Quantifying Bolus Residue and Its Risks in Children: A Videofluoroscopic Study.

Purpose Postswallow residue is a clinical sign of swallow impairment and has shown a strong association with aspiration. Videofluoroscopy (videofluoroscopic study of swallowing [VFSS]) is commonly used to visualize oropharyngeal swallowing and to identify pharyngeal residue. However, subjective binary observation (present or absent) fails to provide important information on volume or location and lacks objectivity and reproducibility. Reliable judgment of changes in residue over time and with treatment is therefore challenging. We aimed to (a) determine the reliability of quantifying pharyngeal residue in children using the bolus clearance ratio (BCR), (b) determine associations between BCR and other timing and displacement measures of oropharyngeal swallowing, and (c) explore the association between BCR and penetration-aspiration in children. Method In this single-center retrospective observational study, we obtained a set of quantitative and descriptive VFSS measures from 553 children (0-21 years old) using a standard protocol. VFSS data were recorded at 30 frames per second for quantitative analysis using specialized software. Results Good interrater (ICC = .86, 95% CI [.74, .961], p < .001) and excellent intrarater reliability was achieved for BCR (ICC = .97, 95% CI [.91, 1.000], p = 001). Significant correlations between BCR and pharyngeal constriction ratio and total pharyngeal transit time were reported (p < .05). Using binomial logistic regression modeling, we found BCR was predictive of penetration-aspiration in children, χ2(13) = 58.093, p < .001, 64.9%. Children with BCR of ≥ 0.1 were 4 times more likely to aspirate. Conclusion BCR is a reliable, clinically useful measure to quantify postswallow residue in children, which can be used to identify and treat children with swallow impairments, as well as to measure outcomes of intervention.

Mixed Consistencies in Dysphagic Patients: A Myth to Dispel

Only limited and inconsistent information about the effect of mixed consistencies on swallowing are available. The aim of this study was to evaluate the location of the head of the bolus at the swallow onset, the risk of penetration/aspiration, and the severity of post-swallow pharyngeal residue in patients with dysphagia when consuming mixed consistencies. 20 dysphagic patients underwent a Fiberoptic Endoscopic Evaluation of Swallowing (FEES) testing five different textures: liquid, semisolid, solid, biscuits-with-milk and vegetable-soup. The location of the head of the bolus at the onset of swallowing was rated using a five-points scale ranging from zero (the bolus is behind the tongue) to four (the bolus falls into the laryngeal vestibule), the severity of penetration/aspiration was rated using the Penetration Aspiration Scale (PAS), the amount of pharyngeal residue after the swallow was rated using the Yale Pharyngeal Residue Severity Rating Scale (YPRSRS) in the vallecula and pyriform sinus. When consuming biscuits-with-milk and liquid the swallow onset occurred more often when the boluses were located in the laryngeal vestibule. Penetration was more frequent with biscuits-with-milk, while aspiration was more frequent with Liquid, followed by biscuits-with-milk and vegetable-soup, Semisolid and Solid. In particular, no differences in penetration and aspiration between liquids and biscuits-with-milk were found as well as among vegetable-soup, semisolid and solid. No significant differences in the amount of food residue after swallowing were demonstrated. The risk of penetration-aspiration for biscuits-with-milk and liquid is similar, while the risk of penetration-aspiration is lower for vegetable-soup than for liquid.

Deep Learning-Based Auto-Segmentation and Evaluation of Vallecular Residue in Videofluoroscopy

Background: Pharyngeal residue is widely considered as an indicator of swallow impairment in videofluoroscopic studies. The volume of residue indicates potential risk for penetration-aspiration on subsequent swallows while the accuracy and measurement guidelines of residue volume estimation varies significantly among human judges and facilities. We aimed to use deep learning to reliably and efficiently estimate the residue volume in vallecular and classify the potential risk alert of penetration to clinicians. Methods: Patients with suspected dysphagia were recruited between 2015 to 2018. We selected 172 qualified residue samples from 3142 swallows. We first developed deep learning algorithm that can efficiently identify and segment the residue area remaining in vallecula. We split our dataset into three parts, with train, test1 (validation) and test2. In the training phase, we deployed transfer learning techniques and ensemble strategies on train dataset. The model was finally determined by its performance on validation dataset. The segmentation performance of this architecture was evaluated on test 2. We also derived $\%(C2-C4)^2$ residue scale using results from our segmentation algorithm and physiological measurement from our previous study. Findings: We tested the reliability among human raters. Testing on a held-out set of swallow cases, ensemble architecture achieved a dice coefficient of 0.72 and 0.70 of segment accuracy on segmentation, and a sensitivity of 0.92 in reference to $\%(C2-C4)^2$ measure scale. Interpretation: These findings demonstrate that automatic deep learning methods hold tremendous promise for improving objectivity in post-swallow residue evaluation, which has historically be a challenge due to carriable training and measurement methods. Funding: NIH Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: The Institutional Review Board at the University of Pittsburgh approved the protocol of this study and all participants were informed and signed the consent.

Quantifying Post-Swallow Residue in Healthy Aging

Purpose Reports are mixed on whether post-swallow residue increases with age. This question was investigated using a quantitative measure of residue in a large cohort of healthy adults. It was hypothesized that post-swallow residue would differ between younger and older healthy adults, and significantly increase in individuals ≥ 80 years. Method In this observational study, 275 healthy volunteers aged 18–99 years underwent videofluoroscopic swallow studies. Post-swallow residue was quantified using the Bolus Clearance Ratio (BCR) for a 20-ml thin liquid barium bolus and 3-cm 3 barium paste bolus. Number of swallows required per bolus and aspiration were also determined as additional markers of swallow efficiency and safety. Results Most BCR values were low, &lt; 0.05 (&lt; 5% of the bolus) for 78% of 20 ml and 66% of paste swallows. BCR values were significantly larger in healthy older adults, although, clinically, the differences are arguably minimal (differences in mean BCR values between age groups: 20 ml: 0.01 [1%]; paste: 0.03 [3%]). For 20 ml, 56% of adults ≥ 80 years performed multiple swallows (oral residue and dose metering) versus 9% of adults 18–39 years. One aspiration event was observed. Conclusions Post-swallow residue was slightly increased in older adults; many individuals ≥ 80 years performed more than one swallow per bolus to achieve this similar level of clearance. This suggests a reduction in swallow efficiency with age without compromising swallow safety. Post-swallow residue that poses a risk of airway invasion should be considered a sign of swallowing dysfunction, not healthy aging.

Mansoura Fiberoptic Endoscopic Evaluation of Swallowing Residue Rating Scale (MFRRS): An Anatomically Based Tool – A Preliminary Study

Objective: The aim of this work was to design an anatomically based scale for judging post-swallow residue in the pharyngeal cavities, for use during the fiberoptic endoscopic evaluation of swallowing (FEES) in patients with dysphagia, and to assess its feasibility. Methods: Two 7-point ordinal scales (one for vallecular residue and one for pyriform sinus residue), were developed using detailed anatomic landmarks to denote residue levels. Hard copy color images of a specified frame, from 210 videos of 30 adult FEES evaluations demonstrating the range of all possible residue patterns, were selected (n = 56 valleculae, 62 pyriform sinuses). Half of these images were used to train 4 raters. The remaining half of the images were randomly ordered and rated by the trained raters. Two weeks later the same images were randomized again, and each rater re-analyzed them. The inter- and intra-rater reliability and criterion validity were determined using the kappa statistics and their standard errors. The internal consistency of the items in MFRRS was examined. Results: MFRRS showed strong inter-rater reliability (valleculae, κ = 0.832 ± 0.038; pyriform sinus, κ = 0.855 ± 0.034), almost perfect intra-rater reliability (valleculae, κ = 0.964 ± 0.018; pyriform sinus, κ = 0.962 ± 0.02), almost perfect concurrent validity (valleculae, κ = 0.968 ± 0.020; pyriform sinus, κ = 0.0971 ± 0.017), and excellent internal consistency (valleculae, Cronbach’s α = 0.990; pyriform sinus, Cronbach’s α = 0.985). Conclusion: MFRRS is a feasible and reliable, anatomically based tool that can provide more accurate pharyngeal residue judgments. The optimized description of residue accumulation patterns can contribute to a better overall description of the functional problem and future description of dysphagia phenotypes.

Swallowing, Chewing and Speaking: Frequently Impaired in Oculopharyngeal Muscular Dystrophy

Background:Oculopharyngeal muscular dystrophy (OPMD) is a late onset progressive neuromuscular disorder. Although dysphagia is a pivotal sign in OPMD it is still not completely understood.Objective:The aim of this study was to systematically investigate oropharyngeal functioning in a large OPMD population.Methods:Forty-eight genetically confirmed OPMD patients completed questionnaires, performed clinical tests on swallowing, chewing, speaking, tongue strength and bite force, and underwent videofluoroscopy of swallowing. Descriptive statistics was used for all outcomes and logistic regression to investigate predictors of abnormal swallowing.Results:Eighty-two percent reported difficulties with swallowing, 27% with chewing and 67% with speaking. Patients performed significantly worse on all oropharyngeal tests compared to age-matched controls except for bite force. Also asymptomatic carriers performed worse than controls: on chewing time, swallowing speed and articulation rate. During videofluoroscopy, all patients (except one asymptomatic) had abnormal residue and 19% aspirated. Independent predictors of abnormal residue were reduced swallowing capacity for thin liquids (OR 10 mL = 0.93; 20 mL = 0.95) and reduced tongue strength for thick liquids (OR 10 mL = 0.95); 20 mL = 0.90). Aspiration of thin liquids was predicted by disease duration (OR = 1.11) and post-swallow residue with 20 mL (OR = 4.03).Conclusion:Next to pharyngeal dysphagia, chewing and speaking are also frequently affected in OPMD patients, even in asymptomatic carriers. Residue after swallowing is a very early sign, while aspiration is a later sign in OPMD. For clinical follow-up monitoring of subjective complaints, swallowing capacity and tongue strength seems relevant.

Quantitative video-fluoroscopic analysis of swallowing in infants

ObjectivesTo utilize objective, quantitative videofluoroscopic swallow measures to profile swallowing in infants and to determine the likelihood of objective swallow measures to predict risk of swallow impairments such as airway violation, reflux and post swallow residue. Study designOur single center retrospective observational study used a cohort of 146 bottle-fed infants (0–9 months) referred for VFSS with any kind of feeding related concern. Frame-by-frame analysis of 20-s video loops of mid-feed sucking was completed to obtain quantitative timing, displacement and coordination measures as well as presence of other findings including aspiration, residue and naso-pharyngeal reflux (NPR) and esophago-pharyngeal reflux (EPR). Spearman correlation, Mann-Whitney U test and binomial logistic regression were conducted to determine statistical associations between swallow measures and binary reporting of swallow impairments. ResultsVideofluoroscopic data of 146 infants were reviewed and analyzed. 49% of infants demonstrated at least one penetration or aspiration event. Total pharyngeal transit time (TPT) and suck-swallow ratio were associated with aspiration (p < .05). Infants with >3 sucks per swallow had significantly longer TPT and their risk of aspiration was greater than those with <3 sucks per swallow (RR 1.23, 95% CI 0.43–8.507, p = .03). Pharyngeal constriction ratio (PCR) and bolus clearance ratio (BCR) were associated with residue, NPR and EPR (p < .05). ConclusionObjective measures provide clinicians with reliable timing and displacement data even in the very young. These measures correlate with swallowing safety and may help to identify enhanced risk in some infants, which may influence management recommendations.

Swallowing, Chewing and Speaking: Frequently Impaired in Oculopharyngeal Muscular Dystrophy.

Oculopharyngeal muscular dystrophy (OPMD) is a late onset progressive neuromuscular disorder. Although dysphagia is a pivotal sign in OPMD it is still not completely understood. The aim of this study was to systematically investigate oropharyngeal functioning in a large OPMD population. Forty-eight genetically confirmed OPMD patients completed questionnaires, performed clinical tests on swallowing, chewing, speaking, tongue strength and bite force, and underwent videofluoroscopy of swallowing. Descriptive statistics was used for all outcomes and logistic regression to investigate predictors of abnormal swallowing. Eighty-two percent reported difficulties with swallowing, 27% with chewing and 67% with speaking. Patients performed significantly worse on all oropharyngeal tests compared to age-matched controls except for bite force. Also asymptomatic carriers performed worse than controls: on chewing time, swallowing speed and articulation rate. During videofluoroscopy, all patients (except one asymptomatic) had abnormal residue and 19% aspirated. Independent predictors of abnormal residue were reduced swallowing capacity for thin liquids (OR 10 mL = 0.93; 20 mL = 0.95) and reduced tongue strength for thick liquids (OR 10 mL = 0.95); 20 mL = 0.90). Aspiration of thin liquids was predicted by disease duration (OR = 1.11) and post-swallow residue with 20 mL (OR = 4.03). Next to pharyngeal dysphagia, chewing and speaking are also frequently affected in OPMD patients, even in asymptomatic carriers. Residue after swallowing is a very early sign, while aspiration is a later sign in OPMD. For clinical follow-up monitoring of subjective complaints, swallowing capacity and tongue strength seems relevant.

EAT-10 Scores and Fiberoptic Endoscopic Evaluation of Swallowing in Head and Neck Cancer Patients.

ObjectiveThe purpose of this study was to determine the relationship between patient‐reported symptoms of oropharyngeal dysphagia (OD) using the Eating Assessment Tool (EAT)‐10 and the swallowing function using a standardized fiberoptic endoscopic evaluation of swallowing (FEES) protocol in head and neck cancer (HNC) patients with confirmed OD.MethodsFifty‐seven dysphagic HNC patients completed the EAT‐10 and a FEES. Two blinded clinicians scored the randomized FEES examinations. Exclusion criteria consisted of presenting with a concurrent neurological disease, scoring below 23 on a Mini‐Mental State Examination, being older than 85 years, having undergone a total laryngectomy, and being illiterate or blind. Descriptive statistics, linear regression, sensitivity, specificity, and predictive values were calculated.ResultsThe majority of the dysphagic patients (N = 38; 66.7%) aspirated after swallowing thin liquid consistency. A large number of patients showed postswallow pharyngeal residue while swallowing thick liquid consistency. More specifically, 42 (73.0%) patients presented postswallow vallecular residue, and 39 (67.9%) patients presented postswallow pyriform sinus residue. All dysphagic patients had an EAT‐10 score ≥ 3. Linear regression analyses showed significant differences in mean EAT‐10 scores between the dichotomized categories (abnormal vs. normal) of postswallow vallecular (P = .037) and pyriform sinus residue (P = .013). No statistically significant difference in mean EAT‐10 scores between the dichotomized categories of penetration or aspiration was found (P = .966).ConclusionThe EAT‐10 questionnaire seems to have an indicative value for the presence of postswallow pharyngeal residue in dysphagic HNC patients, and a value of 19 points turned out to be useful as a cutoff point for the presence of pharyngeal residue in this study population.Level of Evidence: 2b

Efficacy of an education program for nurses that concerns the use of point-of-care ultrasound to monitor for aspiration and pharyngeal post-swallow residue: A prospective, descriptive study

BackgroundFor nurses to provide swallowing care that is appropriate to individual patients’ swallowing functions, techniques for using ultrasound to monitor for aspiration and pharyngeal post-swallow residue would be helpful. ObjectivesThis study seeks to clarify the effectiveness of an education program concerning the use of ultrasound to assess swallowing function (the “Swallowing Point-of-Care Ultrasound Education Program”). This assessment is based on a comparison of the observation skills of general nurses’ and certified nurses in dysphagia nursing in this regard; both groups underwent the education program, but dysphagia nurses have greater knowledge of swallowing functions as a result of their training. MethodsThis prospective descriptive study was conducted as a post-graduate education program in two locations in Japan. The swallowing point-of-care ultrasound education program comprised four elements: e-learning, practical seminar, self-learning, and objective structured clinical examination. The objective structured clinical examination was used after the program to assess whether the participants had obtained the necessary skills. The general nurses were then asked to report the ease-of-use of the education materials. ResultsOf the 32 participants enrolled in the program, 22 general nurses and nine dysphagia nurses completed the program. In the objective structured clinical examination concerning monitoring for aspiration, the dysphagia-nurses group had a higher proportion of participants evaluated as “excellent” (p = 0.007); this group had a significantly higher ability to maintain adequate images during the swallowing process than did the general-nurse group (p = 0.034). However, there was no difference between the two groups regarding monitoring for post-swallowing residue. Further, over 70% of the nurses gave a positive evaluation of the user-friendliness of the e-learning and practical seminar. ConclusionsOur results suggest that the swallowing point-of-care ultrasound education program provides both general nurses and dysphagia nurses with sufficient knowledge and skill to monitor for aspiration and post-swallowing residue.

The Relationship between Swallowing Dynamics and Post-Swallow Residue in Persons with Severe Spastic Cerebral Palsy and Profound Intellectual Disability

The Relationship between Swallowing Dynamics and Post-Swallow Residue in Persons with Severe Spastic Cerebral Palsy and Profound Intellectual Disability

The role of extensional rheology in the oral phase of swallowing: an in vitro study.

Swallowing disorders deteriorate significantly the quality of life and can be life-threatening. Texture modification using shear thinning food thickeners has been proven to be effective in the management of dysphagia. Some studies have recently considered the positive role of cohesiveness, but there is still an insufficient understanding of the effect of the rheological properties of the liquid bolus on the dynamics of bolus transport, particularly when elasticity and extensional properties are combined with a shear thinning behaviour. This study combines steady shear, SAOS and capillary breakage extensional rheometry with an in vitro method to characterize the oral transport of viscoelastic liquids. Bolus velocity and bolus length were measured from exit in vitro experiments using image analysis and related to shear and extensional properties. A theory describing the bolus dynamics shows that the elastic and extensional properties do not influence significantly the oral transit dynamics. Conversely, in vitro results suggest that the extensional properties can affect the transition from the oral to the pharyngeal phase of swallowing, where thin, viscoelastic liquids lead to a fast transit, lower oral post-swallow residues and more compact bolus with a smoother surface, which may suggest a lower risk of fragmentation. This mechanistic explanation suggests that the benefit of the extensional properties of thin viscoelastic liquids in the management of dysphagia should be further evaluated in clinical trials.

The Importance of Extensional Rheology in Bolus Control during Swallowing

Thickened fluids are commonly used in the medical management of individuals who suffer swallowing difficulty (known as dysphagia). Previous studies have shown that the rheological properties of a liquid affect the flow behavior of the bolus in swallowing, such as pharyngeal transit time. While there is no doubt that shear rheology is a highly important factor for bolus flow, it is suspected that extensional properties of a liquid bolus also plays an important role in swallowing, due to elongation of the bolus as it flows through the oropharynx. Our aim in this work was to observe the effect of extensional viscosity on pharyngeal transit time and elongation of the bolus during swallowing. Eight samples of thickened liquid barium that were shear-controlled, but varied in extensional viscosity and two samples that were extensional-controlled, but varied in shear viscosity were swallowed by eight healthy individuals. Data were collected under lateral view of videofluoroscopy swallow study (VFSS); measures of pharyngeal transit time and the ratio of the length to the width of the bolus on the frame of Upper Esophageal Sphincter (UES) opening were taken from the VFSS recordings. It was observed that the pharyngeal transit time generally increases when the fluids are thickened to higher IDDSI consistency. Additionally, higher extensional viscosity fluids reduced the elongation of the bolus during swallowing, thus potentially reducing the risk of post-swallow residue due to bolus breakage. This study confirmed the relevance of the extensional viscosity of the bolus in swallowing.

Changes detected in swallowing function in Friedreich ataxia over 12 months

Friedreich ataxia (FRDA) is a multisystem neurodegenerative disorder and the most common hereditary ataxia. Dysphagia (swallowing impairment) is present in 98% of individuals with FRDA and is characterized by lingual and pharyngeal dysfunction (manifesting in impaired bolus preparation and transfer, and post-swallow residue in the mouth and pharynx), delayed swallow initiation, and entry of material into the airway (penetration/aspiration). Dysphagia severity correlates with disease severity and duration however no longitudinal studies describe changes in function in FRDA. The aim of this study was to investigate the progression of dysphagia in FRDA over one year. Fifty-nine individuals with FRDA and confirmed dysphagia were recruited and 23 of them underwent a second assessment 12 months later. Assessments of swallowing related quality of life, oral motor function (Frenchay Dysarthria Assessment 2nd Ed [FDA-2]) and functional swallowing via videofluoroscopy were conducted. Trials of thin liquid, puree and biscuit were interpreted using the Bethlehem Assessment Scale and the Penetration-Aspiration Scale by two blinded raters. Data from the videofluoroscopy revealed a decline in tongue function, pharyngeal clearance and cricopharyngeal function on solid food. However, severity of penetration/aspiration did not increase. Swallowing-related quality of life and oral-motor function remained stable. A decline in function was observed at three anatomical sites considered important for safe and effective swallowing (tongue, pharyngeal, and cricopharyngeal). However, these deficits did not translate into any meaningful functional decline in swallowing related health over 12 months for individuals with FRDA.

Oropharyngeal dysphagia in early stages of myotonic dystrophy type 1.

Myotonic dystrophy type 1 (DM1) is a multisystemic disorder characterized mainly by skeletal muscle alterations. Although oropharyngeal dysphagia is a prominent clinical feature of DM1, it remains poorly studied in its early disease stages. Dysphagia was investigated in 11 presymptomatic DM1 carriers, 14 patients with DM1 and 12 age-matched healthy controls, by using fiberoptic endoscopic evaluation of swallowing (FEES) and clinical scores. Scores for the FEES variables, delayed pharyngeal reflex, posterior pooling, and postswallow residue were significantly greater in patients with DM1 and in presymptomatic DM1 carriers than in healthy controls (P < 0.05); oropharyngeal dysfunction was more severe in patients than in presymptomatic carriers. Penetration/aspiration was found altered exclusively in patients with DM1 (P < 0.05). Swallowing dysfunction occurs in presymptomatic DM1 carriers. Timely diagnosis of dysphagia in preclinical stages of the disease will aid in the timely management of presymptomatic carriers, potentially preventing medical complications. Muscle Nerve, 2019.

Correlation of Swallowing Function With Bilateral Diaphragmatic Movement in Hemiplegic Stroke Patients.

ObjectiveTo investigate difference in bilateral diaphragm movement of patients with tracheal aspiration according to post stroke residue severity and determine correlations of Penetration-Aspiration Scale (PAS), residue scale, and bilateral diaphragm movement.MethodsA total of 47 patients diagnosed with hemiplegic stroke were enrolled in this study. PAS, severity of valleculae, and pyriform sinus retention during videofluoroscopic swallowing study (VFSS) were assessed. Bilateral fluoroscopic diaphragm movements during spontaneous breathing and forced breathing were measured.ResultsPatients with tracheal aspiration (PAS≥6) had significantly (p=0.035) lower ipsilateral diaphragm movement during spontaneous breathing. Post-swallow residue severity showed statistically significant (p=0.028) difference in patients with ipsilateral diaphragm movement during forced breathing. In linear regression analysis, PAS showed weak correlations with ipsilateral spontaneous diaphragm movement (r=0.397, p=0.006), ipsilateral forced diaphragm movement (r=0.384, p=0.008), and contralateral forced diaphragm movement (r=0.323, p=0.027). Weak correlation was also observed between post swallow residue severity and ipsilateral diaphragm movement during spontaneous breathing (r=0.331, p=0.023) and forced breathing (r=0.343, p=0.018).ConclusionWe confirmed the relationship between swallowing function and bilateral diaphragm movement in this study. The severity of dysphagia after hemiplegic stroke was correlated with bilateral diaphragm movement. Further longitudinal studies are needed to assess the effect of breathing exercise on post-stroke dysphagia.

Reference Values for Healthy Swallowing Across the Range From Thin to Extremely Thick Liquids.

PurposeThickened liquids are frequently used as an intervention for dysphagia, but gaps persist in our understanding of variations in swallowing behavior based on incremental thickening of liquids. The goal of this study was to establish reference values for measures of bolus flow and swallowing physiology in healthy adults across the continuum from thin to extremely thick liquids.MethodA sex-balanced sample of 38 healthy adults underwent videofluoroscopy and swallowed 20% weight-to-volume concentration barium prepared in thin and slightly, mildly, moderately, and extremely thick consistencies using a xanthan gum thickener. Participants took comfortable sips and swallowed without a cue; sip volume was measured based on presip and postsip cup weights. A standard operating procedure (the ASPEKT method: Analysis of Swallowing Physiology: Events, Kinematics and Timing) was used to analyze videofluoroscopy recordings.ResultsThe results clarify that, for thin liquid sips (10–14 ml), a single swallow without clearing swallows is typical and is characterized by complete laryngeal vestibule closure, complete pharyngeal constriction, and minimal postswallow residue. Aspiration was not seen, and penetration was extremely rare. Bolus position at swallow onset was variable, extending as low as the pyriform sinuses in 37% of cases. With thicker liquids, no changes in event sequencing, laryngeal vestibule closure, pharyngeal constriction, or postswallow residue were seen. The odds of penetration were significantly reduced. A longer timing interval until onset of the hyoid burst movement was seen, with an associated higher bolus position at swallow onset. Other timing measures remained unaffected by changes in bolus consistency.ConclusionThe results include new reference data for swallowing in healthy adults across the range from thin to extremely thick liquids.

In vitro and sensory tests to design easy-to-swallow multi-particulate formulations

Flexible dosing and ease of swallowing are key factors when designing oral drug delivery systems for paediatric and geriatric populations. Multi-particulate oral dosage forms can offer significant benefits over conventional capsules and tablets. This study proposes the use of an in vitro model to quantitatively investigate the swallowing dynamics in presence of multi-particulates. In vitro results were compared against sensory tests that considered the attributes of ease of swallowing and post-swallow residues. Water and hydrocolloids were considered as suspending vehicles, while the suspended phase consisted of cellulose pellets of two different average sizes. Both in vivo and in vitro tests reported easier swallow for smaller multi-particulates. Besides, water thin liquids appeared not optimal for complete oral clearance of the solids. The sensory study did not highlight significant differences between the levels of thickness of the hydrocolloids. Conversely, more discriminant results were obtained from in vitro tests, suggesting that a minimum critical viscosity is necessary to enable a smooth swallow, but increasing too much the carrier concentration affects swallowing negatively. These results highlight the important interplay of particle size and suspending vehicle rheology and the meaningful contribution that in vitro methods can provide to pre-screening multi-particulate oral drug delivery systems before sensory evaluation.