Effect of Different Viscosities on Pharyngeal Pressure During Swallowing: A Study Using High-Resolution Manometry

Normative High-Resolution Pharyngeal Manometry: Impact of Age, Size of System, and Sex on Primary Metrics and Pressure Stability

There have been many reports of normative pharyngeal swallowing pressures using high-resolution pharyngeal manometry, but there is a fair amount of between-subject variance in reported pressure parameters. The purpose of this study was to put forward normative pharyngeal high-resolution manometry measures across the lifespan and investigate the effects of age, size of system, and sex. High-resolution pharyngeal manometry was performed on 98 healthy adults (43 males) between the ages 21 and 89. Pressure duration, maxima, integral, and within-individual variability metrics were averaged over 10 swallows of 10-ml thin liquid. Multiple linear and logistic regressions with model fitting were used to examine how pharyngeal pressures relate to age, pharyngeal size, and sex. Age was associated with tongue base maximum pressure, tongue base maximum variability, and upper esophageal sphincter-integrated relaxation pressure (F3,92 = 6.69; p < 0.001; adjusted R2 = 0.15). Pharyngeal area during bolus hold was associated with velopharynx integral (F1,89 = 5.362; p = 0.02; adjusted R2 = 0.05), and there was no significant model relating pharyngeal pressures to C2-C4 length (p < 0.05). Sex differences were best described by tongue base integral and hypopharynx maximum variability (χ2 = 10.27; p = 0.006; pseudo R2 = 0.14). Normative data reveal the distribution of swallow pressure metrics which need to be accounted for when addressing dysphagia patients, the importance of pressure interactions in normal swallow, and address the relative stability of swallow metrics with normal aging.

Residual effect of sequential 4-channel neuromuscular electrical stimulation evaluated by high-resolution manometry

BACKGROUND

High-resolution manometry (HRM) can quantify swallowing pathophysiology to evaluate the status of the pharynx. Sequential 4-channel neuromuscular electrical stimulation (NMES) was recently developed based on the normal contractile sequences of swallowing-related muscles. This study aimed to examine the effects of sequential 4-channel NMES for compensatory application during swallowing and to observe the residual effects after the application of NMES using HRM.

RESULTS

Sequential 4-channel NMES significantly improved the HRM parameters, with respect to the maximal pressure and area of the velopharynx (VP), maximal pressure and area of the mesopharynx (MP), and upper esophageal sphincter (UES) activation and nadir duration. Furthermore, the improvement in the pressure and area variables of the VP and MP showed a tendency to maintain even when measured after NMES, but there are no significant differences.

CONCLUSIONS

The present study suggests that the sequential 4-channel NMES application of the suprahyoid and infrahyoid muscles during swallowing improves the pressure, area, and time variables of the oropharynx, as measured by HRM, and it is likely that the effects may persist even after stimulation. Trial Registration Clinicaltrials.gov, registration number: NCT02718963 (initial release: 03/20/2016, actual study completion date: 06/24/2016, last release: 10/20/2020).

Oral Intake Difficulty and Aspiration Pneumonia Assessment Using High-Resolution Manometry

OBJECTIVE

The sequential generation of swallowing pressure (SP) from the nasopharynx to the proximal esophagus is important for the bolus to pass from the oral cavity to the esophagus. The purpose of this study was to investigate the correlation of the SP sequence mode on high-resolution manometry (HRM) with oral intake difficulty and aspiration pneumonia.

METHODS

Consecutive patients with dysphagia who were admitted to our dysphagia clinic between November 2016 and November 2020 were enrolled in this cross-sectional study. We classified the HRM pressure topography data according to the SP sequence mode into type A, normal; B, partially decreased; C, totally decreased; and D, sequence disappeared, and according to the upper esophageal sphincter (UES) during pharyngeal swallowing into type 1, flattening and 2, non-flattening. Clinical dysphagia severity was determined based on oral intake difficulty and aspiration pneumonia.

RESULTS

In total, 202 patients with dysphagia (mean [standard deviation] age, 68.3 [14.5] years; 140 [69.8%] male) were enrolled. Type C (odds ratio [OR], 10.48; 95% confidence interval [CI], 2.89-51.45), type D (OR, 19.90; 95% CI, 4.18-122.35), and type 2 (OR, 6.36; 95% CI, 2.88-14.57) were significantly related to oral intake difficulty. Type C (OR, 3.23; 95% CI, 1.08-11.12) and type 2 (OR, 4.18; 95% CI, 1.95-9.15) were significantly associated with aspiration pneumonia.

CONCLUSION

The failure of sequential generation of SP was associated with higher risk of oral intake difficulty and aspiration pneumonia. These assessments are useful in understanding the pathophysiology and severity of dysphagia and in selecting safety nutritional management methods.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:2127-2135, 2024.

A Systematic Review of Pharyngeal High-Resolution Manometry Normative Data

PURPOSE

The utilization of high-resolution pharyngeal manometry (HRPM) in the evaluation of pharyngeal dysphagia has been increasing; however, standardization of its use has lagged behind. Without standardization using normative values, it is difficult for clinicians to adopt this emerging technology into meaningful use. Our goal is to map and compare the published normative values for common HRPM metrics in order to help establish consensus reference values.

METHOD

A systematic review was conducted on prospective and retrospective studies that included HRPM metrics, defined by an international working group consensus, in healthy adult populations. Data on the following variables were extracted when available: contractile integrals of the pharynx (PhCI), velopharynx, mesopharynx, and hypopharynx, as well as the upper esophageal sphincter (UES) integrated relaxation pressure (IRP), relaxation time (RT), maximum admittance, and hypopharyngeal intrabolus pressure.

RESULTS

Thirty studies were included. Significant variation existed in the technique and equipment used to perform procedures between the different studies. Lower PhCIs and UES IRPs were seen in younger compared to older individuals. Higher UES RTs were found in individuals in the upright position compared to the supine position and in those using larger boluses sizes or smaller catheters.

CONCLUSIONS

Due to the wide variety of protocols, catheter configurations, manufacturers, and software used in the existing literature, it is difficult to formulate consensus on HPRM normative values using pooled data. Prospective studies adhering to standardized HRPM protocols for specific catheter configurations and manufacturers with larger cohorts of normal individuals are necessary to establish proper reference values for HRPM metrics.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24843753.

Effects of Food and Liquid Properties on Swallowing Physiology and Function in Adults

Foods and liquids have properties that are often modified as part of clinical dysphagia management to promote safe and efficient swallowing. However, recent studies have questioned whether this practice is supported by the evidence. To address this, a scoping review was conducted to answer the question: "Can properties of food and liquids modify swallowing physiology and function in adults?" Online search in six databases yielded a set of 4235 non-duplicate articles. Using COVIDENCE software, two independent reviewers screened the articles by title and abstract, and 229 full-text articles were selected for full-text review. One-hundred eleven studies met the inclusion criteria for qualitative synthesis and assessment of risk of bias. Three randomized controlled trials and 108 non-randomized studies were analyzed. Large amounts of variability in instrumental assessment, properties of food and liquids, and swallowing measures were found across studies. Sour, sweet, and salty taste, odor, carbonation, capsaicin, viscosity, hardness, adhesiveness, and cohesiveness were reported to modify the oral and pharyngeal phase of swallowing in both healthy participants and patients with dysphagia. Main swallow measures modified by properties of food and liquids were penetration/aspiration, oral transit time, lingual pressures, submental muscle contraction, oral and pharyngeal residue, hyoid and laryngeal movement, pharyngeal and upper esophageal sphincter pressures, and total swallow duration. The evidence pooled in this review supports the clinical practice of food texture and liquid consistency modification in the management of dysphagia with the caveat that all clinical endeavors must be undertaken with a clear rationale and patient-specific evidence that modifying food or liquid benefits swallow safety and efficiency while maintaining quality of life.

Deep Learning Analysis to Automatically Detect the Presence of Penetration or Aspiration in Videofluoroscopic Swallowing Study

BACKGROUND

Videofluoroscopic swallowing study (VFSS) is currently considered the gold standard to precisely diagnose and quantitatively investigate dysphagia. However, VFSS interpretation is complex and requires consideration of several factors. Therefore, considering the expected impact on dysphagia management, this study aimed to apply deep learning to detect the presence of penetration or aspiration in VFSS of patients with dysphagia automatically.

METHODS

The VFSS data of 190 participants with dysphagia were collected. A total of 10 frame images from one swallowing process were selected (five high-peak images and five low-peak images) for the application of deep learning in a VFSS video of a patient with dysphagia. We applied a convolutional neural network (CNN) for deep learning using the Python programming language. For the classification of VFSS findings (normal swallowing, penetration, and aspiration), the classification was determined in both high-peak and low-peak images. Thereafter, the two classifications determined through high-peak and low-peak images were integrated into a final classification.

RESULTS

The area under the curve (AUC) for the validation dataset of the VFSS image for the CNN model was 0.942 for normal findings, 0.878 for penetration, and 1.000 for aspiration. The macro average AUC was 0.940 and micro average AUC was 0.961.

CONCLUSION

This study demonstrated that deep learning algorithms, particularly the CNN, could be applied for detecting the presence of penetration and aspiration in VFSS of patients with dysphagia.

Pharyngo-Esophageal Modulatory Swallow Responses to Bolus Volume and Viscosity Across Time

Objectives/Hypothesis

Modulation of the pharyngeal swallow to bolus volume and viscosity is important for safe swallowing and is commonly studied using high‐resolution pharyngeal manometry (HRPM). Use of unidirectional pressure sensor technology may, however, introduce variability in swallow measures and a fixed bolus administration protocol may induce time and order effects. We aimed to overcome these limitations and to investigate the effect of time by repeating randomized measurements using circumferential pressure sensor technology.

Study Design

Sub‐set analysis of data from the placebo arm of a randomized, repeated measures trial.

Methods

HRPM with impedance was recorded using a solid‐state catheter with 36 circumferential pressure sensors and 18 impedance segments straddling from hypopharynx to stomach. Testing included triplicates of 5, 10, and 20 ml thin liquid and 10 ml thick liquid boluses, the order of the thin liquid boluses was randomized. The swallow challenges were repeated approximately 10 minutes after finishing the baseline measurement.

Results

We included 19 healthy adults (10/9 male/female; age 24.5 ± 4.1 year). Intrabolus pressure, all upper esophageal sphincter (UES) opening and relaxation metrics, and flow timing metrics increased with larger volumes. A thicker viscosity decreased UES relaxation time, UES basal pressure, and flow timing metrics, whereas UES opening extent increased. Pre‐swallow UES basal pressure and post‐swallow UES contractile integral decreased over time.

Conclusion

Using circumferential pressure sensor technology, the effects of volume and viscosity were largely consistent with previous reports. UES contractile pressures reduced over time. The growing body of literature offers a benchmark for recognizing aberrant pharyngo‐esophageal motor responses.

Level of Evidence

3 Laryngoscope, 132:1817–1824, 2022

Validation and Inter-rater Reliability of the Modified Videofluoroscopic Dysphagia Scale (mVDS) in Dysphagic Patients with Multiple Etiologies

BACKGROUND

the Videofluoroscopic Dysphagia Scale (VDS) is used to interpret and predict the long-term prognosis of patients with dysphagia. However, the inter-rater agreement of the VDS was shown to be lower in a previous study. To overcome the mentioned limitation of the VDS, a modified version (mVDS) was created and applied clinically. We aimed to validate its usefulness in determining the appropriate feeding method and predicting the prognosis of dysphagia.

METHODS

the videofluroscopic swallowing study (VFSS) data of 50 patients with dysphagia were collected retrospectively. The VFSS data were evaluated using the mVDS, and the inter-rater reliability was calculated. We also evaluated the association between the mVDS and type of feeding method selected, and between the mVDS and presence of aspiration pneumonia in patients with dysphagia.

RESULTS

among the different parameters of mVDS, "aspiration" showed the highest reliability (k = 0.767), followed by "mastication" and "lip closure" (k = 0.648 and k = 0.634, respectively). Conversely, "triggering pharyngeal swallow" and "pyriformis residue" demonstrated the lowest reliabilities (k = 0.312 and k = 0.324, respectively). The intraclass correlation coefficient (ICC), which is used as a measure of the reliability of the total mVDS score, was 0.876. In all patients with dysphagia, the mVDS score correlated significantly with the type of feeding method selected (p < 0.05), and the presence of aspiration pneumonia (p < 0.05).

CONCLUSION

the ICC of the total mVDS score was 0.876. Therefore, the mVDS could be a useful tool for quantifying the severity of dysphagia. It could be helpful in the analysis of the VFSS findings among patients with dysphagia in clinical settings and research.

Comparison of three different types of exercises for selective contractions of supra- and infrahyoid muscles

Several exercise methods, such as the Shaker exercise, tongue press exercise, chin tuck against resistance (CTAR) exercise, and submandibular push exercise, have been introduced to strengthen the muscles involved in swallowing. In this study, we compared the effectiveness of the CTAR, submandibular push, and Shaker exercises for the induction of selective supra- and infrahyoid muscle contractions using surface electromyography (EMG). This study is a prospective non-randomized controlled study. Twenty-five healthy subjects and 20 patients experiencing swallowing difficulty were enrolled. During the three different types of exercises, the root mean square (RMS) values of the sternocleidomastoid (SCM), suprahyoid (anterior belly of the digastric and mylohyoid muscles), and infrahyoid (sternothyroid and thyrohyoid muscles) muscles were analyzed using surface EMG. Differences in the activity of swallowing muscles among the three different exercises were analyzed using one-way repeated measured analysis of variance. In terms of both the maximum and mean RMS values of the suprahyoid muscle, the submandibular push exercise showed a larger RMS value than the CTAR and Shaker exercises in healthy subjects (p < 0.05). In terms of both the maximum and mean RMS values of the suprahyoid muscle, the Shaker exercise and submandibular push exercise showed a larger RMS value than the CTAR exercise in patients with swallowing difficulty (p < 0.05). The submandibular push exercise may be effective as a swallowing muscle exercise owing to its superiority in inducing selective contractions of the supra- and infrahyoid muscles. The CTAR and Shaker exercises are also effective in this regard.

Electromyographic activation patterns during swallowing in older adults

Age-related weakness due to atrophy and fatty infiltration in oropharyngeal muscles may be related to dysphagia in older adults. However, little is known about changes in the oropharyngeal muscle activation pattern in older adults. This was a prospective and experimental study. Forty healthy participants (20 older [> 60 years] and 20 young [< 60 years] adults) were enrolled. Six channel surface electrodes were placed over the bilateral suprahyoid (SH), bilateral retrohyoid (RH), thyrohyoid (TH), and sternothyroid (StH) muscles. Electromyography signals were then recorded twice for each patient during swallowing of 2 cc of water, 5 cc of water, and 5 cc of a highly viscous fluid. Latency, duration, and peak amplitude were measured. The activation patterns were the same, in the order of SH, TH, and StH, in both groups. The muscle activation patterns were classified as type I and II; the type I pattern was characterized by a monophasic shape, and the type II comprised a pre-reflex phase and a main phase. The oropharyngeal muscles and SH muscles were found to develop a pre-reflex phase specifically with increasing volume and viscosity of the swallowed fluid. Type I showed a different response to the highly viscous fluid in the older group compared to that in the younger group. However, type II showed concordant changes in the groups. Therefore, healthy older people were found to compensate for swallowing with a pre-reflex phase of muscle activation in response to increased liquid volume and viscosity, to adjust for age-related muscle weakness.

Effects of Chin-Down Maneuver on Pharyngeal Pressure Generation According to Dysphagia and Viscosity

Objective

To demonstrate the effects of chin-down maneuver on swallowing by using high-resolution manometry (HRM).

Methods

HRM data of 20 healthy subjects and 64 dysphagic patients were analyzed. Participants swallowed 5 mL of thin and honey-like liquids in neutral and chin-down positions. HRM was used to evaluate maximal velopharyngeal pressure/area, maximal tongue base pressure/area, maximal pharyngeal constrictor pressure, pre-/post-swallow upper esophageal sphincter (UES) peak pressure, minimal UES pressure, UES activity time, and nadir duration.

Results

Compared to the neutral position, the chin-down maneuver significantly increased tongue base pressure in both normal and dysphagic groups as well as for both honey-like and thin viscosities, although the honey-like liquid did not reach statistical significance in the dysphagic group. Regarding pharyngeal constrictors and pre-swallow peak UES pressure, the healthy group showed a significant decrease in thin liquid swallowing and decreasing tendency in honeylike liquid swallowing. UES nadir duration was significantly decreased for honey-like liquid swallowing in the dysphagic group and for both thin and honey-like liquids in the healthy group. UES nadir duration of honey-like and thin flow swallowing in the dysphagia group was 0.26 seconds after the chin-down maneuver, which was severely limited.

Conclusion

This study showed a different kinetic effect of the chin-down maneuver between the healthy and dysphagic groups, as well as between thin and honey-like viscosities. The chin-down maneuver increased tongue base pressure and decreased UES nadir duration, which the latter was severely limited in dysphagic patients. Therefore, appropriate application of the chin-down maneuver in clinical practice is required.

Evaluation of the pharynx and upper esophageal sphincter motility using high-resolution pharyngeal manometry for Parkinson's disease

Parkinson's disease (PD) is associated with a high incidence of dysphagia. Aspiration pneumonia due to dysphagia is a major cause of death in patients with PD, and therefore accurately evaluating dysphagia should help improve prognosis. It has been reported that the severity of dysphagia does not always correlate with the Hoehn and Yahr (H&Y) stage for classifying PD severity. However, no reports have quantitatively evaluated the relationship between severity of dysphagia and H&Y stage. High-resolution pharyngeal manometry (HRPM) is a quantitative method that can be used to measure swallowing pressure from the velopharynx to the entry of the upper esophageal sphincter (UES). We used HRPM to measure swallowing pressure in 51 patients with PD. As PD progresses, atrophy and degeneration of the pharyngeal muscles become more pronounced, which contributes to dysphagia. However, thus far there is no quantitative clinical evidence for this pathological change. To evaluate the relationship between severity of underlying PD and dysphagia, patients were categorized by H&Y stage, as follows: stage II in four patients, stage III in 23, stage IV in 14, and stage V in 10. In patients with H&Y stages II, III, IV, and V, the respective velopharyngeal pressures were 179.8 ± 32.5, 157.6 ± 62.2, 172.2 ± 48.9, and 107.4 ± 44.0 mmHg, the mesopharyngeal pressures were 126.8 ± 53.2, 121.6.1 ± 50.4, 142.1 ± 57.8, and 61.4 ± 19.6 mmHg, the residual UES pressure were -8.0 ± 10.8, 10.3 ± 16.1, 16.5 ± 37.9, and 11.2 ± 16.2 mmHg, and the resting UES pressure were 49.5 ± 30.0, 15.8 ± 25.7, 1.85 ± 14.1, and -1.2 ± 12.2 mmHg. Patients with severe PD demonstrated significantly decreased velopharyngeal and oropharyngeal pressures, along with incomplete UES opening and contraction. HRPM can detect subtle abnormalities by quantifying swallowing pressure in patients with PD. Evaluating swallowing pressure with HRPM provides insights into neuromuscular dysfunction that causes abnormal pressure generation during pharyngeal swallowing in patients with PD.

Microbiological analysis of water and thickeners used for people with dysphagia

Thickened fluids are a recognised intervention strategy in use for people with dysphagia. However, their bacterial profile has not previously been examined.

AIMS

To identify bacteria and changes in bacterial profiles in a range of water sources and thickener preparations over a 5-day period.

METHODS

Nine experiments were performed using a range of preparations (sterile, drinking, non-drinking tap water) and a thickening agent (sterile sachet and a used tin).

FINDINGS

No bacteria were grown on serial subcultures of sterile water, both with and without thickener. Drinking, tap and thickened water left at room temperature for 24 hours may become contaminated with environmental organisms.

CONCLUSIONS

The growth of bacteria in preparations of thickening agent appears to be dependent upon water quality, while the proliferation of bacteria is dependent upon the length of time the preparation is allowed to stand at room temperature.

Predictors of Residue and Airway Invasion in Parkinson's Disease

Dysphagia is a highly prevalent disorder in Parkinson's Disease (PD) characterized by changes in swallowing kinematics, residue, and airway invasion. These changes can lead to serious medical morbidities including malnutrition, aspiration pneumonia, and death. However, little is known about the most predictive causes of residue and airway invasion in this patient population. Therefore, the aims of this study were to (1) assess how disease severity affects residue, airway invasion, and swallowing kinematics in PD; and (2) determine which swallowing kinematic variables were most predictive of residue and airway invasion. A secondary analysis of forty videofluoroscopic swallow studies (VFSS) from individuals with early through mid-stage PD was performed. Airway invasion (Penetration-Aspiration Scale 'PAS'), residue (Bolus Clearance Ratio 'BCR'), and ten spatiotemporal swallowing kinematic variables were analyzed. Statistical analyses were used to determine if disease severity predicted residue, depth of airway invasion, and swallowing kinematics, and to examine which swallowing kinematic variables were most predictive of residue and the presence of airway invasion. Results revealed that residue and the presence of airway invasion were significantly predicted by swallowing kinematics. Specifically, airway invasion was primarily influenced by the extent and timing of airway closure, while residue was primarily influenced by pharyngeal constriction. However, disease severity did not significantly predict changes to swallowing kinematics, extent of residue, or depth of airway invasion during VFSS assessment. This study comprehensively examined the pathophysiology underlying dysphagia in people with early to mid-stage PD. The results of the present study indicate that disease severity alone does not predict swallowing changes in PD, and therefore may not be the best factor to identify risk for dysphagia in PD. However, the swallowing kinematics most predictive of residue and the presence of airway invasion were identified. These findings may help to guide the selection of more effective therapy approaches for improving swallowing safety and efficiency in people with early to mid-stage PD.

A computational fluid dynamics simulation of liquid swallowing by impaired pharyngeal motion: bolus pathway and pharyngeal residue

Common practices to improve the ability to swallow include modifying physical properties of foods and changing the posture of patients. Here, we quantified the effects of the viscosity of a liquid bolus and patient posture on the bolus pathway and pharyngeal residue using a computational fluid dynamics simulation. We developed a computational model of an impaired pharyngeal motion with a low pharyngeal pressure and no pharyngeal adaptation. We varied viscosities from 0.002 to 1 Pa·s and postures from -15° to 30° (from nearly vertical to forward leaning). In the absence of pharyngeal adaptation, a honey-like liquid bolus caused pharyngeal residue, particularly in the case of forward-leaning postures. Although the bolus speed was different among viscosities, the final pathway was only slightly different. The shape, location, and tilting of the epiglottis effectively invited a bolus to two lateral pathways, suggesting a high robustness of the swallowing process.NEW & NOTEWORTHY Thickening agents are often used for patients with dysphagia. An increase in bolus viscosity not only reduces the risk of aspiration but also can cause a residual volume in the pharynx. Because information obtained from videofluoroscopic swallowing studies is only two-dimensional, measurement of pharyngeal residue is experimentally difficult. We successfully quantified the three-dimensional bolus pathway and the pharyngeal residual volume using computational modeling and simulation.

New Swallowing Method to Improve Pharyngeal Passage of a Bolus by Creating Negative Pressure in the Esophagus-Vacuum Swallowing

Supplemental digital content is available in the text.

Herein, we present a case of a patient with Wallenberg syndrome with severe bulbar dysphagia who discovered a unique swallowing method: creating strong negative pressure in the esophagus to improve pharyngeal passage of a bolus. A 47-yr-old man presented with a subarachnoid hemorrhage secondary to a ruptured aneurysm in the right vertebral artery. After coil embolization, he experienced severe dysphagia due to Wallenberg syndrome and required tube feeding. Eighty-one days after the onset of the stroke, a videofluoroscopic swallowing evaluation revealed that the bolus was rapidly sucked into the esophagus. High-resolution manometry showed weak constriction of the pharynx simultaneous with forced, voluntary constriction of the diaphragm before swallowing; this created negative pressure in the esophagus. The authors named this unique swallowing method “vacuum swallowing.” Ultimately, the patient was able to eat an ordinary diet via the use of this technique. Vacuum swallowing is a unique method of improving pharyngeal passage of a bolus by creating strong negative pressure in the esophagus. Additional studies are necessary to determine whether vacuum swallowing can be successfully used for other forms of dysphagia.

Feasibility of high-resolution manometry for decision of feeding methods in patients with amyotrophic lateral sclerosis

As amyotrophic lateral sclerosis (ALS) progresses, dysphagia gets worse due to the weakening of pharyngeal musculature. As oral feeding becomes more difficult or dangerous due to worsening dysphagia, tracheal aspiration, or undernutrition, the necessity for tube feeding becomes increasingly important. This study aims to establish a standard pressure point by applying pharyngeal pressure using high-resolution manometry (HRM) to start tube feeding in patients with ALS.This study was designed as a retrospective analysis of prospectively collected data. Forty-one patients with ALS and 20 healthy subjects were participated. Both groups were evaluated using HRM, videofluoroscopic swallowing study (VFSS), and pulmonary function test. The swallowing pressure along the velopharynx (VP), tongue base (TB), pre-upper esophageal sphincter (UES), lower pharynx, and cricopharyngeus, as well as minimal UES pressure were measured using HRM.There was significantly positive correlation between the pressure of cricopharyngeus and forced expiratory volume in 1 second (FEV1). And there were significant correlations between results of VFSS and FEV1, FEV1%, forced vital capacity (FVC), and FVC%. There was a significant difference in the pressure of TB and cricopharyngeus between the control group and the ALS patient group. The pressures of VP, TB, lower pharynx, and cricopharyngeus have a significant correlation with the recommended feeding type by VFSS.Because it is possible to use HRM to quantitatively assess pharyngeal and respiratory weaknesses and it is more sensitive than other evaluation tools, the cutoff value of HRM parameters may be used to decide the feeding type in patients with ALS.

Clinical characteristics of dysphagic stroke patients with salivary aspiration: A STROBE-compliant retrospective study

The aim of this study was to evaluate the correlation between radionuclide salivagram findings and clinical characteristics in stroke patient with swallowing difficulty.In this study, dysphagic stroke patients who had undergone both a radionuclide salivagram and videofluoroscopic swallowing study (VFSS) were included retrospectively. To evaluate the correlations between clinical parameters and salivary aspiration, clinical parameters, such as stroke lesion, the degree of paralysis, sex, age, onset duration of stroke, the score of the Mini-Mental State Examination (MMSE), the score of the Global Deterioration Scale (GDS), the total score of the Modified Barthel Index (MBI), and each sub-score of the MBI were collected and analyzed.In the results of this study, the MMSE score was the only significant parameter for predicting positive findings in a salivagram in a multivariate logistic regression analysis in patients with supratentorial stroke. In patients with infratentorial stroke, however, the transfer sub-score of MBI was the only significant parameter for predicting positive findings in a salivagram in a multivariate logistic regression analysis.In conclusion, care should be taken to prevent salivary aspiration when the MMSE score is less than eight in patients with supratentorial stroke, and the transfer sub-score of MBI score is less than three in patients with infratentorial stroke.

A systematic review of current methodology of high resolution pharyngeal manometry with and without impedance

PURPOSE

This systematic review appraises and summaries methodology documented in studies using high resolution pharyngeal manometry (HRM) with and without impedance technology (HRIM) in adult populations.

METHODS

Four electronic databases CINAHL, EMBASE, MEDLINE, and Cochrane Library were searched up to, and including March 2017. Studies reporting pharyngeal HRM/HRIM for swallowing and/or phonatory assessment, published in peer-reviewed journals in English, German, or Spanish were assessed for the inclusion criteria. Of the selected studies, methodological aspects of data acquisition and analysis were extracted. Publications were graded based on their level of evidence and quality of methodological aspects was assessed.

RESULTS

Sixty-two articles were identified eligible, from which 50 studies reported the use of HRM and 12 studies used HRIM. Of all included manuscripts, the majority utilized the ManoScan™ system (64.5%), a catheter diameter of 4.2 mm was most prevalently documented (30.6%). Most publications reported the application of topical anesthesia (53.2%). For data analysis in studies using HRM, software intrinsic to the recording system was reported most frequently (56%). A minority of the studies using HRM provided data about measurement reliability (10%). This is higher for studies using HRIM (50%).

CONCLUSIONS

Considerable methodological variability exists regarding data acquisition and analysis in published studies using HRM/HRIM. Lacking reports of methodology make study replications difficult and reduce the comparability across studies. More data regarding the impact of individual methodological aspects on study outcomes are further required for the development of methodological recommendations.

The effect of radionuclide solution volume on the detection rate of salivary aspiration in the radionuclide salivagram: A STROBE-compliant retrospective study

Despite the possibility that the methodological difference of this salivagram may influence the results for detection rate, there has been no study on the effect of the solution volume on detection rate. Moreover, to date, since the introduction of the nucleotide salivagram, there has been a tendency that a constant solution volume and nucleotide dose is not used in studies. Therefore, the aim of this study is to investigate the effect of solution volume on the detection rate of a salivagram in patients with brain lesion, and to determine the optimal solution volume of salivagram. We retrospectively reviewed clinical data and solution volume of radionuclide used in the salivagram of 77 patients with dysphagia, and the patients were divided into 2 groups according to the solution volume of the radionuclide (Group A-0.1 mL vs Group B-0.5 mL). Although, there was no significant difference between 2 groups in clinical data, there was a statistically significant difference in the detection rate of salivary aspiration between the 2 groups (3.3% vs 19.1%). Even a small difference of the solution volume of radionuclide in salivagram can affect the detection rate of salivary aspiration in patients with brain lesion. Further study with various solution volumes of radionuclide is warranted to determine the optimal solution volume of the radionuclide salivagram.