Swallowing pressure and pressure profiles in young healthy adults

The Manometric Representation of the Upper Esophageal Sphincter During the Resting State: A Descriptive Study

The upper esophageal sphincter (UES) is the high-pressure zone marking the transition between the hypopharynx and esophagus. There is limited research surrounding the resting UES using pharyngeal high-resolution manometry (HRM) and existing normative data varies widely. This study describes the manometric representation of the resting UES using a clinically accessible method of measurement. Data were obtained from 87 subjects in a normative database of pharyngeal HRM with simultaneous videofluoroscopy. The resting UES manometric region was identified and ten measurement segments of this region were taken throughout the duration of the study using the Smart Mouse function within the manometry software. Intraclass correlation coefficients (ICC) were used to analyze within-subject reliability across measurements. Linear mixed-effects regression models were used to analyze how subject characteristics and manometric conditions influence resting UES pressure. There was excellent within-subject reliability between resting UES mean pressures (ICC = 0.96). In bivariate analysis, there were significant effects of age, number of sensors contained within the resting UES, and preceding swallow volume on mean resting UES pressure. For every 1 unit increase in age, there was a 0.19 unit decrease in resting UES pressure (p = 0.008). For every 1 unit increase in number of sensors contained within the resting UES, there was a 3.71 unit increase in resting UES pressure (p < 0.001). This study presents normative data for the resting UES, using a comprehensive and clinically accessible protocol that can provide standard comparison for the study of populations with swallowing disorders, particularly UES dysfunction, and provides support for UES-directed interventions.

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.

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.

Feel it or deal with it: Oral perception and aspiration risk in early stroke

BACKGROUND

Sensation and perception impairments are significant problems faced by individuals with early-stage stroke. Sensory inputs needed in swallowing guide the perceptual process with the involvement of cognitive functions. In the absence of sensory input, bolus perception may be altered, and swallowing safety may be compromised.

OBJECTIVES

This study aims to evaluate the oral perception of volume change and the aspiration risk of individuals with stroke and determine the relationship between oral perception and aspiration risk.

METHODS

Total participants were 35. The Gugging Swallowing Screening Test (GUSS) was used to determine individuals' risk of aspiration and divide them into groups 'aspiration risk' and 'non-aspiration risk'. The Oral Perception of Liquid Volume Changes Test (OPLVCT) was used to determine the level of oral perception.

RESULTS

The groups were statistically similar in terms of age and other descriptives. When the OPLVC test was examined, the scores of the aspiration risk group were significantly lower (p < .001). In addition, a moderate negative correlation was found between aspiration risk and the OPLVC scores (r: -0.502; p < .001).

CONCLUSION

In this study, a relationship was found between aspiration risk and oral perception. It also revealed that individuals with stroke who are at risk of aspiration have low oral perception abilities. Based on these results, it was concluded that these individuals cannot reliably determine the maximum volume of liquid to be consumed without assistance. We suggest that evaluations and training of oral perception should be added to the rehabilitation of individuals with stroke.

Effect of Topical Nasal Anesthetic on Comfort and Swallowing in High-Resolution Impedance Manometry

OBJECTIVES/HYPOTHESIS

Use of topical nasal anesthetic (TNA) is common in high-resolution impedance manometry (HRIM). This study investigated the effect of TNA on swallowing and procedure tolerability during HRIM with a 4.2-mm catheter, a more commonly used catheter size with impedance capabilities.

STUDY DESIGN

Randomised experimental study with blinding of participants.

METHODS

Twenty healthy participants (mean age = 33 years, 16 female) were randomized to undergo HRIM using the ManoScan™ ESO Z 4.2-mm catheter twice, 1 week apart, under two conditions: with TNA (viscous lidocaine) and with placebo. Analyses included esophageal data of three saliva, three saline (5 mL), and three bread swallows (2 cm × 2 cm) performed while reclined 45°, and pharyngeal data under the same conditions while seated upright. Pharyngeal and upper esophageal sphincter (UES) HRIM parameters were analyzed using the Swallow Gateway analysis platform. Visual analogue scale (VAS) scores rating procedural comfort were analyzed.

RESULTS

There were no significant physiological differences in pharyngeal and UES parameters between conditions. There were also no significant differences in VAS scores under placebo (mean = 54.8, standard deviation (SD) = 19.3) and TNA (mean = 60.0, SD = 21.9) (t[19] = -0.9, P = .4) conditions; however, there was a significant difference in the first versus second session (t[19]) = 5.1, P < .05).

CONCLUSIONS

TNA did not improve comfort, but it also did not significantly affect swallowing behavior. There was, however, a practice effect regardless of TNA use with improved tolerance of the 4.2-mm catheter and likely more natural swallowing behavior during the second session of HRIM.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

Blowing time ratio and high-resolution manometry to evaluate swallowing function of patients with oral and oropharyngeal cancer

OBJECTIVE

The blowing time ratio, which is the ratio of the blowing time when the nostrils are open and closed, is significantly correlated with velopharyngeal pressure, not only during speech but also during swallowing. This study aimed to further evaluate the usefulness of the blowing time ratio as a screening tool to evaluate the swallowing pressure of patients treated for oral and oropharyngeal cancers using high-resolution manometery (HRM).

METHODS

Ten patients treated for oral or oropharyngeal cancer were recruited for this study. Swallowing pressures at the velopharynx, oropharynx, and upper esophageal sphincter (UES) were measured using HRM. Their correlations with the blowing time ratio were analyzed.

RESULTS

The blowing time ratio was significantly correlated with the swallowing pressures of the oropharynx (CC = 0.815, p = 0.004) and the velopharynx (CC = 0.657, p = 0.039), but not of the UES.

CONCLUSIONS

The present results further support our previous finding that the blowing time ratio is a useful screening tool to evaluate velopharyngeal and oropharyngeal swallowing pressures in patients treated for oral and oropharyngeal cancer.

Conformable AlN Piezoelectric Sensors as a Non-invasive Approach for Swallowing Disorder Assessment

Deglutition disorders (dysphagia) are common symptoms of a large number of diseases and can lead to severe deterioration of the patient's quality of life. The clinical evaluation of this problem involves an invasive screening, whose results are subjective and do not provide a precise and quantitative assessment. To overcome these issues, alternative possibilities based on wearable technologies have been proposed. We explore the use of ultrathin, compliant, and flexible piezoelectric patches that are able to convert the laryngeal movement into a well-defined electrical signal, with extremely low anatomical obstruction and high strain resolution. The sensor is based on an aluminum nitride thin film, grown on a soft Kapton substrate, integrated with an electrical charge amplifier and low-power, wireless connection to a smartphone. An ad-hoc designed laryngeal motion simulator (LMS), which is able to mimic the motions of the laryngeal prominence, was used to evaluate its performances. The physiological deglutition waveforms were then extrapolated on a healthy volunteer and compared with the sEMG (surface electromyography) of the submental muscles. Finally, different tests were conducted to assess the ability of the sensor to provide clinically relevant information. The reliability of these features permits an unbiased evaluation of the swallowing ability, paving the way to the creation of a system that is able to provide a point-of-care automatic, unobtrusive, and real-time extrapolation of the patient's swallowing quality even during normal behavior.

Adequate Number of Swallows for Pharyngeal Pressure Measurement of a Subject using High-resolution Manometry

Introduction  The number of pressure measurements that need to be recorded using high-resolution manometry (HRM) for the accurate evaluation of pharyngeal function is not well established.

Objective  The purpose of this study is to clarify the number of swallows required to obtain an accurate pharyngeal manometric profile of a person.

Methods  Forty healthy adults performed a dry swallow and bolus swallows using 3-, 5-, or 10 ml of water and underwent measurements using the Starlet HRM system. Each subject underwent 10 swallows for each of the four bolus volume conditions.

Results  The mean of up to seven measurements of maximum pre-swallow upper esophageal sphincter pressure with 10 ml of swallow was close to the mean of up to eight measurements in 95% of the subjects. Similarly, the rate of change of the average for the eighth and ninth measurements and the rate of change for the average of the ninth and tenth measurements were less than 5%. When the other parameters were similarly measured up to the sixth measurement, no major change in the average value was observed even if more measurements were taken.

Conclusion  A minimum of six measurements are required, and seven swallows are sufficient for evaluating the pharyngeal manometric profile of a single person. This number of measurements can be a useful criterion when performing HRM measurements on individual subjects.

TMS brain mapping of the pharyngeal cortical representation in healthy subjects

BACKGROUND

Brain mapping is fundamental to understanding brain organization and function. However, a major drawback to the traditional Brodmann parcellation technique is the reliance on the use of postmortem specimens. It has therefore historically been difficult to make any comparison regarding functional data from different regions or hemispheres within the same individual. Moreover, this method has been significant limited by subjective boundaries and classification criteria and therefore suffer from reproducibility issues. The development of transcranial magnetic stimulation (TMS) offers an alternative approach to brain mapping, specifically the motor cortical regions by eliciting quantifiable functional reactions.

OBJECTIVE

To precisely describe the motor cortical topographic representation of pharyngeal constrictor musculature using TMS and to further map the brain for use as a tool to study brain plasticity.

METHODS

51 healthy subjects (20 male/31 female, 19-26 years old) were tested using single-pulse TMS combined with intraluminal catheter-guided high-resolution manometry and a standardized grid cap. We investigated various parameters of the motor-evoked potential (MEP) that include the motor map area, amplitude, latency, center of gravity (CoG) and asymmetry index.

RESULTS

Cortically evoked response latencies were similar for the left and right hemispheres at 6.79 ± 0.22 and 7.24 ± 0.27 ms, respectively. The average scalp positions (relative to the vertex) of the pharyngeal motor cortical representation were 10.40 ± 0.19 (SE) cm medio-lateral and 3.20 ± 0.20 (SE) cm antero-posterior in the left hemisphere and 9.65 ± 0.24 (SE) cm medio-lateral and 3.18 ± 0.23 (SE) cm antero-posterior in the right hemisphere. The mean motor map area of the pharynx in the left and right hemispheres were 9.22 ± 0.85(SE) cm²and 10.12 ± 1.24(SE) cm², respectively. The amplitudes of the MEPs were 35.94 ± 1.81(SE)uV in the left hemisphere and 34.49 ± 1.95(SE)uV in the right hemisphere. By comparison, subtle but consistent differences in the degree of the bilateral hemispheric representation were also apparent both between and within individuals.

CONCLUSION

The swallowing musculature has a bilateral motor cortical representation across individuals, but is largely asymmetric within single subjects. These results suggest that TMS mapping using a guided intra-pharyngeal EMG catheter combined with a standardized gridded cap might be a useful tool to localize brain function/dysfunction by linking brain activation to the corresponding physical reaction.

Three-dimensional imaging of upper esophageal sphincter resting pressure

OBJECTIVE

High-resolution manometry (HRM) is used to analyze upper esophageal sphincter (UES) physiology. Conventional HRM can yield imprecise measurements of UES resting pressure given its unidirectional sensors and averaging of circumferential pressure. In contrast, three-dimensional (3D) measurements can yield precise UES resting pressure data over the entire length of the UES. This study conducted a detailed analysis of UES resting pressure as evaluated by 3D-HRM.

METHODS

Seventeen young, healthy adult participants (7 females and 10 males) were recruited. The 3D-HRM system used includes a pressure sensor catheter (outer diameter, 4 mm) and eight-channel transducers arranged circumferentially to acquire pressure data at 45° intervals. The catheter was inserted transnasally into the esophagus and automatically retracted at a speed of 1 mm/s. Participants performed the following tasks: maintain resting breathing, perform breath holding, and perform the Valsalva maneuver. Data were obtained and compared per millimeter over the longitudinal UES length.

RESULTS

Clear 3D waveforms were identified, with greater mean UES pressures in anterior-posterior directions than in lateral directions (P < .05). The anterior distribution was located superior to the posterior portion. Significant differences were observed in mean UES pressures and UES resting integrals between resting breathing and the Valsalva maneuver (P < 0.05). No differences in functional UES length were observed.

CONCLUSIONS

The normal UES resting pressure was not directionally uniform in the luminal structure. 3D-HRM imaging of UES resting pressure can help deepen our understanding of UES physiology.

LEVEL OF EVIDENCE

4.

Elicitation of the Swallowing Reflex by Esophageal Stimulation in Healthy Subjects: An Evaluation Using High-Resolution Manometry

The purposes of this human study using high-resolution manometry were to verify whether the swallowing reflex can be evoked by intra-esophageal fluid injection and whether the reflex latency and manometric variables differ depending on the injected location, amount, or speed. Ten healthy individuals participated in this study. The tip of the intranasal catheter for injection was placed at 5 cm (upper), 10 cm (upper-middle), 15 cm (lower-middle), or 20 cm (lower) from the distal end of the upper esophageal sphincter (UES). An intra-esophageal injection of 3 mL or 10 mL of thickened water was administered and controlled at 3 mL/s or 10 mL/s. Latencies from the start of the injection to the onset of UES relaxation were compared regarding injection locations, amounts, and rates. Manometric variables of intra-esophageal injection and voluntary swallowing were compared. The latency became shorter when the upper region was injected. Latency after the 10-mL injection was shorter than that after the 3-mL injection (p < 0.01) when faster injection (10 mL/s) was used. Faster injection induced shorter latency (p < 0.01) when a larger volume (10 mL) was injected. Pre-maximum and post-maximum UES pressures during voluntary swallowing or during spontaneous swallowing when injecting the upper esophageal region were significantly higher than spontaneous swallowing at other regions (p < 0.01). Intra-esophageal fluid injection induces the swallowing reflex in humans. The most effective condition for inducing the swallowing reflex involved a larger fluid amount with a faster injection rate in the upper esophagus.

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 pharyngeal contractile integral is a useful indicator of pharyngeal swallowing impairment

BACKGROUND

A limitation to the expanded use of high-resolution pharyngeal manometry (HRPM) in clinical practice is the lack of useful pharyngeal parameters that are easy to interpret, generalizable between patients, and do not require specialized software. In this study, we sought to test the relationship between the pharyngeal contractile integral (PhCI) with videofluoroscopic abnormalities as assessed with the Modified Barium Swallow Impairment Profile^© ™.

METHODS

Adult dysphagic patients were recruited to undergo simultaneous HRPM and videofluoroscopy during a standardized swallowing protocol.

KEY RESULTS

Thirty-six patients were included in the study. The mean PhCI was 247 mm Hg·cm·s (range 2-488 mm Hg·cm·s). The lower pharyngeal total (PT) group (N=20; mean PT=3.9) had a mean PhCI of 299 mm Hg·cm·s, while the higher PT group (N=16; mean PT=12.7) had a mean PhCI score of 188 mm Hg·cm·s (P=.01). There was also a significant negative correlation between normalized PhCI to PT scores (r=-.47; P=.004). Patients with higher PhCIs exhibited less severe penetration-aspiration scores on thin liquids (1.44 vs 3.78; P=.03) and all consistencies combined (1.21 vs 1.99; P=.03).

CONCLUSIONS & INFERENCES

The PhCI is a useful indicator of the presence of pharyngeal swallowing impairment and is technically simple to calculate with currently available software programs. Advancement of software is necessary to refine the clinical value of this parameter. High-resolution pharyngeal manometry has the potential to be a valuable adjunct procedure for the evaluation and treatment of dysphagic individuals.

Multimodal Swallowing Evaluation with High-Resolution Manometry Reveals Subtle Swallowing Changes in Early and Mid-Stage Parkinson Disease

BACKGROUND

Parkinson disease (PD) has detrimental effects on swallowing function. Treatment options are largely behavioral; thus, patients would benefit from an earlier start to therapy. Early swallowing changes in PD are not well-known, so patients do not typically receive swallowing treatment until later in the progression of PD.

OBJECTIVE

We used predictive modeling to determine what quantitative swallowing variables best differentiate individuals with early to mid-stage PD from healthy controls.

METHODS

Participants included twenty-six individuals with early to mid-stage PD and 26 healthy, age- and sex-matched controls. Swallowing was evaluated by simultaneous high-resolution manometry and videofluoroscopy as well as the Sydney Swallow Questionnaire (SSQ). Binomial logistic regression was performed on 4 sets of data: 1) high-resolution manometry only; 2) videofluoroscopy only; 3) SSQ only; and 4) all data combined.

RESULTS

A model from a combined data set had the highest accuracy in differentiating individuals with PD from controls. The model included maximum pressure in the velopharynx (soft palate), pressure variability in the velopharynx, and the SSQ item concerning difficulty with swallowing saliva. No significant models could be generated using the videofluoroscopy data.

CONCLUSIONS

Individuals with PD show quantitative changes in pressure generation and are able to self-assess aspects of swallowing function in the early and mid-stages of PD, even in the absence of swallowing changes seen on videofluoroscopy. A multimodal approach for the assessment of swallowing may be more accurate for determining subtle swallowing changes that occur in the early stages of PD.

Preliminary Evaluation of Functional Swallow After Total Laryngectomy Using High-Resolution Manometry

INTRODUCTION

Understanding of swallowing pressures after total laryngectomy (TL) and what constitutes a "functional" swallow are limited. Mobile structures are altered or removed after TL, with consequent effects on pressure profiles. High-resolution manometry (HRM) can characterize these pressures.

METHODS

Six TL subjects without dysphagia and 6 controls underwent pharyngeal HRM. Timing and pressure variables for the velopharynx, mesopharynx, and upper esophageal sphincter (UES) were compared. Changes in variables due to bolus volume were evaluated in TL subjects.

RESULTS

The TL subjects had increased duration of velopharyngeal pressure (P = .012). Maximum mesopharyngeal pressure was lower versus controls (P = .003). Maximal and total pre-opening (P = .002, P = .002) and post-closure (P = .001, P = .002) UES pressures were lower. Maximum mesopharyngeal pressure (P = .032) decreased with increasing bolus volume.

CONCLUSIONS

Increased velopharyngeal pressure duration and total swallow duration reflect separation of the pharynx into distinct conduits for air and food, thus ensuring successful bolus passage without the need for respiration. Decreased UES pressure highlights the effects of disrupting the cricopharyngeal and rostral esophageal muscle fibers from their attachments to the larynx and performing a cricopharyngeal myotomy. Additional studies including subjects with dysphagia could further characterize the functional TL swallow and identify aspects susceptible to dysfunction.

Propagation Curve and Velocity of Swallowing Pressure in Healthy Young Adults

The objective of this study is to construct a propagation curve and determine propagation velocities in young healthy adults examined using a 2.64-mm-diameter high-resolution manometry catheter with 36 circumferential sensors; to explore data reproducibility; and to determine whether the swallowing pressure (SP) propagation velocity correlated with bolus volume. Repeated measures with subjects serving as their own controls. Thirty healthy subjects (average age 25.3 years) swallowed saliva and 2, 5, and 10 mL of cold water to determine the maximum SP from the soft palate to the cervical esophagus. The SP propagation curve was obtained by plotting the duration to reach each SP peak. The SP propagation velocity was calculated for each region. These parameters were examined according to bolus size and gender. The intra-class correlation coefficient for estimating the SP propagation curves was >0.61 (i.e., highly consistent). The propagation velocity was maximal at the meso-hypopharynx and minimal at the UES and cervical esophagus. The SP propagation curve was very reproducible within any subject. Neither the water volume (with the exception of 2 and 5 mL) nor gender exerted any apparent effect on velocity in any region. However, the velocity was quite variable at the cervical esophagus.

Oral perception of liquid volume changes with age

Bolus volume has been widely studied, and research has demonstrated a variety of physiological impacts on swallowing and swallowing disorders. Oral perception of bolus volume has not, to our knowledge, been investigated in association with normal ageing processes. Research suggests many sensory changes with age, some within the oral cavity, and changes in swallowing function with age have been defined. The role of perception in oropharyngeal deglutition with age requires further investigation. The purpose of this study was to establish the psychophysical relationship between liquid volume and oral perception and examine changes with age. Healthy young and older adults were prospectively assessed using a magnitude estimation task differentiating five volumes of water delivered randomly to the oral cavity. Results suggest a fourfold increase in liquid volume is required by older participants to perceive an approximate twofold increase in the perception of volume compared with younger healthy adults. Sensory receptors in the oral cavity provide a feedback loop that modulates the swallowing motor response so that it is optimal for the size and consistency of the bolus. Changes in perception of bolus volume with age are consistent with other perceptual changes and may provide valuable information regarding sensorineural rehabilitation strategies in the future.

Temporal characteristics of hyolaryngeal structural movements in normal swallowing

OBJECTIVES/HYPOTHESIS

To evaluate the relationship between movements of hyolaryngeal structures and fluid bolus transition in normal swallowing using automatized kinematic analysis of the videofluoroscopic swallowing study (VFSS).

STUDY DESIGN

A prospective, descriptive study.

METHODS

Seventy-five healthy volunteers underwent VFSS with 2 mL of diluted barium. The timing and sequence of structural movements were measured for laryngeal elevation (LE), hyoid excursion (HE), epiglottic rotation (ER), and fluid bolus transition.

RESULTS

The rapid movement of LE (reference time point) was initiated simultaneously with the fluid bolus head passing the mandibular angle (-0.05 s, P = .07), followed by rapid onset of HE with significant temporal difference (P < .001). After the hyoid onset, onset of ER (0.17 s, P < .001), entrance of the bolus through upper esophageal sphincter (0.33 s, P < .001), maximal point of LE (0.52 s, P < .001), HE (0.53 s, P = .344), and maximal point of ER (0.64 s, P < .001) followed sequentially. For subgroup analysis, we classified 50 subjects without premature bolus loss (PBL) or pharyngeal triggering delay (PTD) into the "early group," and 24 subjects with PBL or PTD for <1 s into the "late group." In both groups, the sequence of the structural movements did not change. The early group showed significant correlation between the fluid transition and structural movements; both LE and HE were initiated when the bolus passed the mandibular angle, and the ER was initiated when the bolus reached the vallecula.

CONCLUSIONS

We demonstrated a characteristic pattern of hyolaryngeal structural movements in normal swallowing. The results may serve as a basis for classifying and analyzing aspiration patterns in patients with dysphagia.

LEVEL OF EVIDENCE

NA.

Can mano-videoendoscopy substitute for videofluorography in evaluation of upper esophageal sphincter function?

CONCLUSIONS

Mano-videoendoscopy (MVE), a manometry technique with endoscopic confirmation of the pressure catheter, can supplement the information on upper esophageal sphincter (UES) function, and overcomes the drawbacks of videoendoscopic swallowing study (VESS).

OBJECTIVES

This study aimed to investigate the possibility of replacing videofluorographic swallowing study (VFSS) with MVE, as a test to precisely evaluate UES function.

METHODS

Data from 52 patients with dysphagia were retrospectively reviewed. All patients underwent both MVE and VFSS for evaluation of dysphagia. The manometry was performed with a transnasally inserted catheter (2.6 mm outer diameter and four pressure sensors) under endoscopic observation. The sensors were kept at the tongue base, upper pyriform sinus, apex of pyriform sinus, and UES. We statistically compared the manometric parameters of UES relaxation with fluorographic UES opening.

RESULTS

Fluorographic UES opening was diagnosed as good in 34 patients and poor in 18 patients. The nadir pressure, pressure drop, and pressure rise in the UES had significant correlation on the fluorographic UES opening. Stepwise logistic regression test revealed that pressure drop, the gap between the resting pressure and the nadir of UES pressure, was a robust parameter for predicting fluorographic UES opening, and the cut-off level to anticipate good fluorographic opening was ≥ 33.5 mmHg (specificity, 0.853; sensitivity, 0.759).