Timing of glottic closure during normal swallow

Acoustic, aerodynamic, and vibrational effects of ventricular folds adduction in an ex vivo experiment

Objectives

The excessive adduction of ventricular folds has been observed in patients with dysphonia and professional singers. Whether these changes in the ventricular folds are the cause or just a result of disease progression remains unclear, and their potential pathological and physiological implications are yet to be determined. This study aimed to examine the impact of different degrees of ventricular adduction on acoustics, aerodynamics, and vocal fold vibration.

Methods

The excised models of mild and severe ventricular adduction were established. We recorded the vibration pattern of vocal folds and ventricular folds and measured acoustic metrics, including fundamental frequency (F0), Jitter, Shimmer, harmonic-to-noise ratio (HNR), and sound pressure level (SPL). Furthermore, we evaluated the aerodynamics index through phonation threshold pressure (PTP), phonation instability pressure (PIP), mean flow rate (MFR), phonation threshold flow (PTF), and phonation instability flow (PIF).

Results

Irregular vibrations of the ventricular fold were observed during ventricular adduction. Notably, mild and severe ventricular adduction conditions showed a significant increase in PTP, Shimmer, and Jitter, whereas MFR, PIF, and HNR decreased compared with the control condition.

Conclusions

Ventricular adduction leads to the deterioration of acoustic and aerodynamic parameters. The aperiodic and irregular vibration of the ventricular folds may be responsible for this phenomenon, although further experiments are warranted. Understanding the functioning of ventricular folds can be beneficial in directing the treatment of muscle tension dysphonia and improving voice training techniques.Level of evidence: level 4.

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

PURPOSE

The current investigation aimed to establish preliminary normative data for endoscopic swallow studies (FEES). The investigators collected data for three timing measures (time to whiteout, duration of whiteout, and total swallow time), three swallowing outcomes (safety, efficiency, and number of swallows per bolus), and one physiologic event (glottal response), for both healthy young and older adults using two liquid volumes, one pureed bolus and a solid bolus.

METHODS

Blinded raters retrospectively analyzed 65 randomly selected, deidentified videos of endoscopic swallowing examinations from a pool of 163 young and older adults with typical swallowing abilities. Timing measures and analysis of airway invasion, amount of residue, number of swallows, and glottal response were obtained.

RESULTS

Preliminary means and quartiles were established for healthy adults in two age groups (young and old), for time to whiteout (WO), number of swallows per bolus, glottal response, Yale Residue Rating Scale Scores, Penetration-Aspiration Scale scores, duration of WO, and total swallow duration. Differences were found between the older and younger groups.

CONCLUSION

The current study represents a preliminary attempt to provide quantitative and normative values for FEES. These data represent reference values to which other bolus presentations and populations can be compared. The data represents proof of concept and merits additional investigation.

IRB ID

1756246-2: Approved 2022/06/06.

CLINICAL TRIAL REGISTRATION

Study does not meet criteria. DATA REPOSITORY: https://doi.org/10.6084/m9.figshare.25800025 .

Timing of True Vocal Cords Closure for Safe Swallowing: A Review of 5 Studies Using 3D Analysis Using Computerized Tomography (CT)

Timely and complete laryngeal closure is critical for a successful swallow. Researchers have studied laryngeal closure, including true vocal cords (TVC) closure, closure of the arytenoids to the epiglottis base (laryngeal vestibule closure), and epiglottic inversion, but the most commonly available imaging tools have limitations that do not allow the study of these components individually. Swallowing computerized tomography (CT) has enabled three-dimensional dynamic visualization and quantitative evaluation of swallowing events providing a unique view of swallowing-related structures and their motion. Using CT, TVC closure can be visualized and evaluated on any plane or cross-section without being obscured by of laryngeal vestibule closure or epiglottis inversion. The current review summarizes the results of five papers evaluating the effects of bolus consistency and volume, posture, and age on TVC closure. The combined results of these studies suggest that TVC closure is responsive to oral sensory input based on bolus consistency and size and can be modulated in response to conditions perceived to increase the risk of airway invasion. These results are meaningful for dysphagia rehabilitation as it suggests that interventions to improve TVC closure are likely to enhance airway protection.

Determining the Relationship Between Hyoid Bone Kinematics and Airway Protection in Swallowing

PURPOSE

Research remains equivocal regarding the links between hyoid movement and penetration-aspiration. The aims of this study were (a) to explore associations between hyoid parameters, laryngeal vestibule closure (LVC) parameters, and penetration-aspiration on thin liquids; and (b) to determine which of these parameters are the strongest predictors of penetration-aspiration.

METHOD

This study involved retrospective analysis of an existing videofluoroscopy data set, collected in 305 participants (152 males) with noncongenital/nonsurgical/non-oncological risk for dysphagia. We extracted data for six thin liquid swallows per participant, and obtained measures of hyoid movement (peak position, speed) and LVC (complete/incomplete, timing, duration). Resulting values were coded as typical/atypical relative to healthy reference data. Relationships were explored using chi-square tests and odds ratios (a) for the entire data set and (b) for the subset of data with complete LVC. Hierarchical logistic regression models determined the strongest predictors of penetration-aspiration.

RESULTS

Significant associations were found between penetration-aspiration and incomplete LVC, prolonged time-to-most-complete-LVC, short LVC duration, reduced anterior hyoid peak position, and reduced hyoid speed. Hyoid measures were also significantly associated with LVC parameters. In the first regression model, incomplete LVC and prolonged time-to-most-complete-LVC were the only significant predictors of penetration-aspiration. For cases with complete LVC, the only significant predictor was prolonged time-to-most-complete-LVC.

CONCLUSIONS

Although reduced anterior hyoid peak position and speed are associated with penetration-aspiration on thin liquids, these measures do not independently account for penetration-aspiration when considered in conjunction with measures of LVC. When identifying mechanisms explaining penetration-aspiration, clinicians should focus on LVC (complete/incomplete) and timeliness of LVC.

Aesthesiometer-Based Testing for Laryngopharyngeal Hyposensitivity

OBJECTIVES/HYPOTHESIS

To develop a method for threshold estimation of the laryngeal adductor reflex (LAR) response using Cheung-Bearelly monofilaments.

STUDY DESIGN

Cross-sectional.

METHODS

Twenty-two healthy adults (12 men, 10 women) were tested for LAR response outcome using 30 mm 5-0 and 4-0 nylon monofilaments. Tactile stimuli were delivered to the aryepiglottic (AE) fold and medial pyriform sinus (MPS). Dichotomous classifier features and performance (area under the curve (AUC)), the LAR response outcome agreement and disagreement matrix, and test-retest reliability were examined. From those data, a test protocol that would minimize patient burden to estimate the LAR triggering threshold was formulated.

RESULTS

Classifier performance of 5-0 monofilament stimulation of the AE fold (sensitivity = 0.63, specificity = 0.63, PPV = 0.74, NPV = 0.25) and MPS (sensitivity = 0.45, specificity = 0.77, PPV = 0.74, NPV = 0.23,) was slightly below that of 4-0 monofilament stimulation of the AE fold (sensitivity = 0.82, specificity = 0.50, PPV = 0.82, NPV = 0.50) and MPS (sensitivity = 0.84, specificity = 0.64, PPV = 0.90, NPV = 0.56), based on AUC. LAR response outcome agreement for 5-0 and 4-0 stimulations was high (93%) for 5-0 positive response, but low (29%) for 5-0 negative response. Aesthesiometer test-retest reliability for LAR response outcome was excellent (Cronbach's alpha = 0.97).

CONCLUSIONS

Threshold estimation of the LAR response may be operationalized by adopting a decision tree protocol. For negative LAR response to initial 5-0 monofilament stimulation and positive response to subsequent 4-0 monofilament stimulation, the higher threshold is confirmed. Positive LAR response to 5-0 or 4-0 monofilament stimulation is expected in over 90% of asymptomatic adults. Negative LAR response to 4-0 monofilament stimulation identifies patients at risk for laryngopharyngeal hyposensitivity.

LEVEL OF EVIDENCE

3b Laryngoscope, 2021.

Laryngeal Adductor Reflex Movement Latency Following Tactile Stimulation

OBJECTIVE

To measure the latency of laryngeal adductor reflex (LAR) motion onset at 2 laryngopharyngeal subsites using calibrated aesthesiometers.

STUDY DESIGN

Cross-sectional.

SETTING

Academic institution.

METHODS

Twenty-one asymptomatic, healthy subjects (11 male, 10 female) underwent laryngopharyngeal sensory testing with tactile stimuli delivered to the aryepiglottic fold and medial pyriform sinus using 30-mm Cheung-Bearelly monofilaments (4-0 and 5-0 nylon sutures) via channeled flexible laryngoscope. The LAR onset latency, defined as the first visual detection of ipsilateral vocal fold adduction following tactile stimulation, was measured with frame-by-frame analysis of video recordings.

RESULTS

The overall mean LAR latency across both subsites and stimulation forces was 176.6 (95% CI, 170.3-183.0) ms, without significant difference between subsites or forces. The critical value for LAR response latency prolongation at the .01 significance level was 244 ms. At 30 frames/s video capture resolution, LAR response latency ≥8 frame intervals would indicate abnormal prolongation.

CONCLUSION

Aesthesiometer-triggered LAR latency appears to be invariant over an 8.7-dB force range and between the aryepiglottic fold and medial pyriform sinus subsites in controls. Laryngeal adductor reflex latency incongruences between stimulation forces or laryngopharyngeal subsites may serve as pathophysiological features to dissect mechanisms of upper aerodigestive tract disorders.

LEVEL OF EVIDENCE

Level 3B.

Automatic Estimation of Laryngeal Vestibule Closure Duration Using High- Resolution Cervical Auscultation Signals

Purpose

Safe swallowing requires adequate protection of the airway to prevent swallowed materials from entering the trachea or lungs (i.e., aspiration). Laryngeal vestibule closure (LVC) is the first line of defense against swallowed materials entering the airway. Absent LVC or mistimed/ shortened closure duration can lead to aspiration, adverse medical consequences, and even death. LVC mechanisms can be judged commonly through the videofluoroscopic swallowing study; however, this type of instrumentation exposes patients to radiation and is not available or acceptable to all patients. There is growing interest in noninvasive methods to assess/monitor swallow physiology. In this study, we hypothesized that our noninvasive sensor- based system, which has been shown to accurately track hyoid displacement and upper esophageal sphincter opening duration during swallowing, could predict laryngeal vestibule status, including the onset of LVC and the onset of laryngeal vestibule reopening, in real time and estimate the closure duration with a comparable degree of accuracy as trained human raters.

Method

The sensor-based system used in this study is high-resolution cervical auscultation (HRCA). Advanced machine learning techniques enable HRCA signal analysis through feature extraction and complex algorithms. A deep learning model was developed with a data set of 588 swallows from 120 patients with suspected dysphagia and further tested on 45 swallows from 16 healthy participants.

Results

The new technique achieved an overall mean accuracy of 74.90% and 75.48% for the two data sets, respectively, in distinguishing LVC status. Closure duration ratios between automated and gold-standard human judgment of LVC duration were 1.13 for the patient data set and 0.93 for the healthy participant data set.

Conclusions

This study found that HRCA signal analysis using advanced machine learning techniques can effectively predict laryngeal vestibule status (closure or opening) and further estimate LVC duration. HRCA is potentially a noninvasive tool to estimate LVC duration for diagnostic and biofeedback purposes without X-ray imaging.

Variations in the amplitude and duration of hyolaryngeal elevation during swallow: Effect of sour and carbonated liquid bolus

BACKGROUND

Altering sensory properties of food is relevant to the management of swallowing disorders. The current investigation aimed to examine the influence of sour and carbonated stimuli on measures of hyolaryngeal elevation.

METHOD

Sixty healthy adults in the age range of 18 to 35 years were assessed using Digital Accelerometry Swallowing Imaging (DASI) while swallowing 5 ml of neutral, sour and carbonated liquid bolus.

RESULTS

Sour stimulus was significantly different with higher amplitude and longer durational measures of hyolaryngeal elevation compared to the two other stimuli.

CONCLUSION

Sour stimulus facilitates better hyolaryngeal elevation, which implicates its usage in dysphagia management.

Quantifying Airway Invasion and Pharyngeal Residue in Patients with Dementia

Previous research has begun to elucidate the physiological impairments associated with dysphagia in patients with dementia, but in order to select the most appropriate targets of intervention we need to better understand consequences of dysphagia. The purpose of this study was to quantify penetration, aspiration, and residue in people with dementia, and confirm if residue was associated with airway invasion on subsequent swallows. Videofluoroscopy clips of sips of thin and extremely thick liquid barium from 58 patients with dementia were retrospectively analyzed. Ratings of swallowing safety, using the Penetration⁻Aspiration Scale (PAS), and efficiency, using Normalized Residue Ratio Scale in the valleculae (NRRSv) and pyriform sinuses (NRRSp), were made on all swallows. Over 70% of both thin and extremely thick liquid swallows were found to be safe (PAS < 3). Results also revealed that residue was generally more common in the valleculae. However, the proportion of thin liquid swallows with significant NRRSp that were unsafe on the subsequent swallow was significantly greater than the proportion of swallows with significant NRRSp that were safe on the subsequent swallow. As such, there was a 2.83 times greater relative risk of penetration⁻aspiration in the presence of thin liquid pyriform sinus residue. Future research should determine the impaired physiology causing aspiration and residue in this population.

"Hidden in Plain Sight": A Descriptive Review of Laryngeal Vestibule Closure

A major emphasis in the evaluation of swallowing is to identify physiological abnormalities in swallowing that contribute to or explain unsafe swallowing (i.e., ingested material enters the trachea; post-swallow residue in the pharynx). Impairments in laryngeal vestibule closure are widely recognized as one of the major causes of unsafe swallowing, as it is the primary mechanism and first line of defense for preventing material from penetrating the airway during swallowing. However, this complex mechanism is often overlooked and understudied in swallowing research and dysphagia management. The purpose of this review is to promote a better understanding of the mechanism of laryngeal vestibule closure. We discuss where gaps in research exist and propose future directions for incorporating laryngeal vestibule closure as a primary outcome measure in swallowing research. Additionally, we propose that an increased knowledge of the mechanism of laryngeal vestibule closure will increase diagnostic accuracy and optimize dysphagia management for patients with dysphagia.

Evidence that an internal schema adapts swallowing to upper airway requirements

KEY POINTS

To swallow food and liquid safely, airway protection is essential. Upward and forward movements of the hyoid and larynx in the neck during swallowing vary in magnitude between individuals. In healthy human adults, hyoid and laryngeal movements during swallowing were scaled by differences in initial upper airway area before swallowing. Individuals increased laryngeal elevation during swallowing in response to increased airway opening before swallowing. We show that when upper airway protection requirements change, individuals use an internal sensorimotor scaling system to adapt movements to maintain swallow safety.

ABSTRACT

Hyoid and laryngeal movements contribute to laryngeal vestibule closure and upper oesophageal sphincter opening during swallowing. Evidence of an internal sensorimotor scaling system allowing individuals to achieve these functional goals is lacking. In speech, speakers adjust their articulatory movement magnitude according to the movement distance required to reach an articulatory target for intelligible speech. We investigated if swallowing is similar in that movement amplitude may be scaled by the functional goal for airway protection during swallowing, rather than by head and neck size. We hypothesized that healthy individuals adapt to their own anatomy by adjusting hyo-laryngeal movements to achieve closure of the upper airway. We also investigated if individuals would automatically compensate for changes in their initial hyo-laryngeal positions and area when head position was changed prior to swallowing. Videofluoroscopy was performed in 31 healthy adults. Using frame-by-frame motion analysis, anterior and superior hyoid and laryngeal displacement, and hyo-laryngeal area were measured prior to and during swallowing. Kinematic measurements during swallowing were examined for relationships with pharyngeal neck length, and initial hyo-laryngeal positions, length and area before swallowing. During swallowing, individuals altered laryngeal elevation magnitude to exceed hyoid elevation based on hyo-laryngeal length before swallowing. Anterior laryngeal displacement was related to initial larynx distance from the spine, while hyoid elevation was predicted by pharyngeal neck length and initial hyoid distance from the mandible prior to the swallow. In conclusion, individuals automatically adapt hyo-laryngeal movement during swallowing based on targets required for closing the hyo-laryngeal area for safe swallowing.

Independent exercise for glottal incompetence to improve vocal problems and prevent aspiration pneumonia in the elderly: a randomized controlled trial

Objectives:

To evaluate the effect of a self-controlled vocal exercise in elderly people with glottal closure insufficiency.

Design:

Parallel-arm, individual randomized controlled trial.

Methods:

Patients who visited one of 10 medical centers under the National Hospital Organization group in Japan for the first time, aged 60 years or older, complaining of aspiration or hoarseness, and endoscopically confirmed to have glottal closure insufficiency owing to vocal cord atrophy, were enrolled in this study. They were randomly assigned to an intervention or a control group. The patients of the intervention group were given guidance and a DVD about a self-controlled vocal exercise. The maximum phonation time which is a measure of glottal closure was evaluated, and the number of patients who developed pneumonia during the six months was compared between the two groups.

Results:

Of the 543 patients enrolled in this trial, 259 were allocated into the intervention group and 284 into the control; 60 of the intervention group and 75 of the control were not able to continue the trial. A total of 199 patients (age 73.9 ±7.25 years) in the intervention group and 209 (73.3 ±6.68 years) in the control completed the six-month trial. Intervention of the self-controlled vocal exercise extended the maximum phonation time significantly (p < 0.001). There were two hospitalizations for pneumonia in the intervention group and 18 in the control group, representing a significant difference (p < 0.001).

Conclusion:

The self-controlled vocal exercise allowed patients to achieve vocal cord adduction and improve glottal closure insufficiency, which reduced the rate of hospitalization for pneumonia significantly.

ClinicalTrial.govIdentifier-UMIN000015567

The Sequence of Swallowing Events During the Chin-Down Posture

PURPOSE

This study investigated the effect of the chin-down posture on the sequence of swallowing events in healthy adults.

METHOD

Sixteen healthy participants performed 45 5-ml thin liquid swallows during videofluoroscopy: 5 neutral head position, 30 chin-down posture, and then 10 neutral head position. Eight swallowing events were measured: the time of hyoid burst, bolus head in the pharynx, bolus tail in the pharynx, laryngeal vestibule closure (LVC), upper esophageal sphincter (UES) opening, bolus head in the UES, bolus tail exiting the pharynx, and laryngeal vestibule opening (LVO).

RESULTS

Our key finding is that LVC was one of the first 3 swallowing events in 69% of neutral swallows and in 78% of chin-down swallows (p = .006). Also, LVO occurred last in 14% of chin-down swallows but never occurred last in the preceding neutral swallows (p ≤ .001). Thus, in chin-down swallows, LVC occurred earlier and LVO occurred later.

CONCLUSIONS

The chin-down posture may be beneficial for individuals with delayed onset of LVC and reduced duration of the LVC. Future studies are needed to examine this effect in individuals with dysphagia.

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.

Influence of the chin-down and chin-tuck maneuver on the swallowing kinematics of healthy adults

The purpose of the study was to investigate the influence of the chin-tuck maneuver on the movements of swallowing-related structures in healthy subjects and formulate standard instructions for the maneuver. A total of 40 healthy volunteers (20 men and 20 women) swallowed 10 mL of diluted barium solution in a “normal and comfortable” position (NEUT), a comfortable chin-down position (DOWN), and a strict chin-tuck position (TUCK). Resting state anatomy and kinematic changes were analyzed and compared between postures. Although angles of anterior cervical flexion were comparable between DOWN (46.65 ± 9.69 degrees) and TUCK (43.27 ± 12.20), the chin-to-spine distance was significantly shorter in TUCK than in other positions. Only TUCK showed a significantly shorter anteroposterior diameter of the laryngeal inlet (TUCK vs. NEUT, 14.0 ± 4.3 vs. 16.3 ± 5.0 mm) and the oropharynx (18.8 ± 3.1 vs. 20.5 ± 2.8 mm) at rest. The maximal horizontal displacement of the hyoid bone was significantly less in TUCK (9.6 ± 3.0 mm) than in NEUT (12.6 ± 2.6 mm; p < 0.01) or DOWN (12.1 ± 3.0 mm; p < 0.01). TUCK facilitated movement of the epiglottic base upward (TUCK vs. NEUT, 15.8 ± 4.7 vs. 13.3 ± 4.5 mm; p < 0.01). In contrast, DOWN increased the horizontal excursion of the epiglottic base and reduced movement of the vocal cords. These results quantitatively elucidated the biomechanical influences of the chin-tuck maneuver including reduced horizontal movement of the hyoid bone, facilitation of vertical movement of the epiglottic base, and narrowing of the airway entrance. Comparing DOWN and TUCK, only TUCK induced significant changes in the airway entrance, hyoid movement, and epiglottic base retraction.

Electrophysiological evaluation of oropharyngeal Dysphagia in Parkinson's disease

Parkinson’s disease (PD) is a chronic, neurodegenerative movement disorder that typically affects elderly patients. Swallowing disorders are highly prevalent in PD and can have grave consequences, including pneumonia, malnutrition, dehydration and mortality. Neurogenic dysphagia in PD can manifest with both overt clinical symptoms or silent dysphagia. Regardless, early diagnosis and objective follow-up of dysphagia in PD is crucial for timely and appropriate care for these patients. In this review, we provide a comprehensive summary of the electrophysiological methods that can be used to objectively evaluate dysphagia in PD. We discuss the electrophysiological abnormalities that can be observed in PD, their clinical correlates and the pathophysiology underlying these findings.

Event sequence variability in healthy swallowing: building on previous findings

This study builds on previous work by Kendall, Leonard, and McKenzie, which investigated event sequence variability for 12 paired events during swallowing by healthy volunteers. They identified four event pairs that always occurred in a stereotyped order and a most common occurring overall order of events during swallowing. In the current study, we investigated overall event sequencing and the same four paired events in a sample of swallows by healthy young (under 45 years old) volunteers. Data were collected during a 16-swallow lateral videofluoroscopy protocol, which included manipulations of bolus volume, barium density, bolus viscosity, and swallow cueing. Our results agreed with previous findings that variable event sequencing is found in healthy swallowing, and, in regard to obligatory sequencing of two paired events, movement of the arytenoids toward the base of the epiglottis begins prior to upper esophageal sphincter (UES) opening and maximum hyolaryngeal approximation occurs after UES opening. However, our data failed to replicate the previous findings that there is obligatory sequencing of maximum pharyngeal constriction after maximal UES distension and the UES opens before bolus arrival at the UES. The most common observed overall event sequence reported by Kendall et al. was observed in only 4/293 swallows in our dataset. Manipulations of bolus volume, bolus viscosity, barium concentration, swallow cueing, and swallow repetitions could not completely account for the differences observed between the two studies.

Dysphagia after Stroke: an Overview

Dysphagia affects the vast majority of acute stroke patients. Although it improves within 2 weeks for most, some face longstanding swallowing problems that place them at risk for pneumonia, malnutrition, dehydration, and significantly affect quality of life. This paper discusses the scope, the disease burden, and the tools available for screening and formal evaluation of dysphagia. The most common and recently developed treatment interventions that might be useful in the treatment of this population are discussed.

Variation in temporal measures of swallowing: sex and volume effects

Temporal measures of healthy swallowing appear to be variably sensitive to bolus and participant factors based on a recent meta-analysis of studies in the deglutition literature. In this carefully controlled study of healthy young volunteers, balanced for sex and height, we sought to understand the influence of bolus volume and participant sex on the three durations and three intervals most frequently reported in the deglutition literature. Three boluses per target volume (5, 10, and 20 ml) were repeated for each participant (n = 20, 10 male) using a spontaneous swallow paradigm in lateral view videofluoroscopy. None of the temporal durations or intervals was found to be correlated with participant height above an a priori cutoff point of r ≥ 0.3. Further, none of the temporal durations or intervals varied significantly by participant sex. Bolus volume significantly impacted upper esophageal sphincter (UES) opening duration, laryngeal closure duration, the laryngeal closure-to-UES opening interval, and the pharyngeal transit time interval, but not hyoid movement duration or the stage transition duration interval. When participants are sampled in such a manner as to represent the range of height reported to be typical for both sexes in the population, sex does not significantly influence temporal measures of swallowing.

Prolonged swallowing time in dysphagic Parkinsonism patients with aspiration pneumonia

OBJECTIVE

To quantitatively measure which dysphagic features, including swallowing time and hyoid bone displacement, would be associated with increased risk of aspiration pneumonia in dysphagic Parkinsonism patients.

DESIGN

Clinical survey.

SETTING

Tertiary care center.

PARTICIPANTS

Patients with Parkinsonism and dysphagia (N=25), referred for videofluoroscopic swallowing study, were recruited by retrospective review of medical records. They were divided into 2 groups according to the history of aspiration pneumonia.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Swallowing time including onset of pharyngeal swallowing, oral transit time and pharyngeal transit time, and maximum hyoid bone displacement including total, horizontal, and vertical displacement during swallowing in thin and thick bariums were recorded.

RESULTS

Patients with history of aspiration pneumonia had significantly longer pharyngeal transit time (4.14 vs 2.31s, P=.038) and onset of pharyngeal swallowing (2.16 vs 1.04s, P=.031) than those without, when swallowing thin barium. Patients with aspiration pneumonia also had significantly longer swallowing time when swallowing thick barium (oral transit time: 7.14 vs 2.33s, P=.018; pharyngeal transit time: 6.39 vs 1.23s, P=.004; onset of pharyngeal swallowing: 5.11 vs .31s, P=.006). There was no significant difference in hyoid bone displacement between the 2 groups.

CONCLUSIONS

Patients with Parkinsonism dysphagia and aspiration pneumonia had longer swallowing time than those without, but there was no difference in displacement of hyoid bone.

Temporal variability in the deglutition literature

A literature review was conducted on temporal measures of swallowing in healthy individuals with the purpose of determining the degree of variability present in such measures within the literature. A total of 46 studies that met inclusion criteria were reviewed. The definitions and descriptive statistics for all reported temporal parameters were compiled for meta-analysis. In total, 119 different temporal parameters were found in the literature. The three most-frequently occurring durational measures were upper esophageal sphincter opening, laryngeal closure, and hyoid movement. The three most-frequently occurring interval measures were stage transition duration, pharyngeal transit time, and duration from laryngeal closure-to-UES opening. Subtle variations in operational definitions across studies were noted, making the comparison of data challenging. Analysis of forest plots compiling descriptive statistical data (means and 95% confidence intervals) across studies revealed differing degrees of variability across durations and intervals. Two parameters (UES opening duration and the laryngeal closure-to-UES opening interval) demonstrated the least variability, reflected by small ranges for mean values and tight confidence intervals. Trends emerged for factors of bolus size and participant age for some variables. Other potential sources of variability are discussed.

Observation of arytenoid movement during laryngeal elevation using videoendoscopic evaluation of swallowing

The purpose of this study was to confirm that the arytenoid regions dynamically adduct and extend upward toward the epiglottis during laryngeal elevation. While 14 healthy volunteers aged 19-32 years old swallowed 5 ml of white soft yogurt in one gulp without chewing, the movement of the arytenoid regions was observed for videoendoscopic evaluation of swallowing (VE). Each moving image was stored simultaneously on videotape. A cross-sectional area surrounded by the epiglottis and the bilateral arytenoid regions (S) and the length of a straight line passing through the anterior borders of the left and right arytenoid regions (L) were measured. The relative area of the entrance in the laryngeal vestibule was calculated as [S/L (2)] before the swallowing reflex (resting condition), just before laryngeal closure, and just after laryngeal closure. [S/L (2)] was smaller just before epiglottal descent than at the resting condition, and became smallest just after the epiglottis started to ascend. The mean area narrowed to 37.9% of the resting area just after laryngeal closure and in the most extreme case to 8.7% of the resting area. It was demonstrated that the arytenoid regions adducted and extended up toward the epiglottis during laryngeal elevation. The technique used to measure the cross-sectional area of the entrance in the laryngeal vestibule employing VE was an effective analytical procedure.

Evaluation of swallowing using 320-detector-row multislice CT. Part II: kinematic analysis of laryngeal closure during normal swallowing

The purpose of this study was to (1) depict normal dynamic swallowing and (2) measure (a) the temporal characteristics of three components of laryngeal closure, i.e., true vocal cord (TVC) closure, closure of the laryngeal vestibule at the arytenoid to epiglottic base, and epiglottic inversion, and (b) the temporal relationship between these levels of laryngeal closure and other swallowing events, hyoid elevation, and the pharyngoesophageal segment (PES) using 320-detector-row multislice computed tomography (320-MSCT). The swallowing of a 10-ml portion of honey-thick liquid (5% w/v) was examined in six healthy volunteers placed in a 45° reclining position. Three-dimensional CT images were created in 29 phases at an interval of 0.10 s over a 2.90-s duration. Dynamic swallowing and TVC movement were depicted clearly. The sequence for laryngeal closure was the following: (1) the hyoid started to elevate, (2) the PES opened, (3) TVC closure and closure at the arytenoid to epiglottic base occurred almost simultaneously during the hyoid elevation, and (4) the epiglottic maximum inversion occurred after the hyoid maximum displacement. Those results indicated that the onset of hyoid elevation and the early opening of the PES occurring before three levels of laryngeal closure are critical components for airway protection. 320-MSCT allowed the 3D depiction and kinematic analysis of target structures, which will increase our knowledge of airway protection mechanisms during swallowing.

Identification of distinct swallowing patterns for different bolus volumes

OBJECTIVE

To investigate the time interval between glottic closure and the opening of upper esophageal sphincter during swallowing, by means of the coupling of electromyographical (EMG) recordings on the thyroarytenoid (TA) and the cricopharyngeus (CP) muscles.

METHODS

TA-EMG and CP-EMG pause were recorded by concentric needle electrodes using time-locked delay-line circuitry of the EMG apparatus. EMG data obtained from a total of 273 swallows of saliva, 3, 5, 10 and 15 ml volumes of water, were compared.

RESULTS

The relation between the onsets of TA-EMG activity and the CP-EMG pause demonstrated three different patterns of swallows. Pattern A was the delay of the onset of TA-EMG between 50-500 ms, and pattern B was the overlap of its activity with the CP-EMG pause. Pattern C was the earlier occurrence of the TA-EMG 50-550 ms before the CP-EMG pause. Pattern A was the most frequent type of swallows whereas the pattern C appeared during swallowing of larger volumes.

CONCLUSIONS

Physiologically, there is a delay of the TA activation after the onset of CP-EMG pause during swallowing of small amounts in healthy subjects.

SIGNIFICANCE

This physiological phenomenon could be a potential risk of aspiration in patients with neurogenic dysphagia.

Coordination of Mastication, Swallowing and Breathing

The pathways for air and food cross in the pharynx. In breathing, air may flow through either the nose or the mouth, it always flows through the pharynx. During swallowing, the pharynx changes from an airway to a food channel. The pharynx is isolated from the nasal cavity and lower airway by velopharyngeal and laryngeal closure during the pharyngeal swallow. During mastication, the food bolus accumulates in the pharynx prior to swallow initiation. The structures in the oral cavity, pharynx and larynx serve multiple functions in breathing, speaking, mastication and swallowing. Thus, the fine temporal coordination of feeding among breathing, mastication and swallowing is essential to provide proper food nutrition and to prevent pulmonary aspiration. This review paper will review the temporo-spatial coordination of the movements of oral, pharyngeal, and laryngeal structures during mastication and swallowing, and temporal coordination between breathing, mastication, and swallowing.

Flexible Endoscopic Evaluation of Swallowing in Healthy Young and Older Adults

Objectives:

Scant data exist on normal swallowing as assessed endoscopically. A lack of understanding for the range of normal swallowing may lead to inaccurate diagnoses and overly aggressive management of patients with dysphagia. Accordingly, the purpose of this study was to determine the effects of age (ie, young versus older), gender, bolus volume (ie, 5 versus 10 mL), and bolus condition (ie, water versus milk) on Penetration-Aspiration Scale scores, bolus dwell time, pharyngeal closure duration, and residue in healthy adults.

Methods:

Twenty-three young adults (mean, 30.0 years of age) and 21 older adults (mean, 75.0 years of age) participated. Measurements were acquired during manoendoscopic swallowing assessments. The participants contributed 8 swallows, affording a study total of 352 swallows for analysis.

Results:

The older adults demonstrated penetration on 19 swallows and aspiration on 11 swallows out of 168 swallows. There was a significant difference in the proportion of Penetration-Aspiration Scale scores across age and gender groups. Longer bolus dwell times were seen in older adults and with milk boluses, whereas residue severity was less in young adults and with water boluses.

Conclusions:

Endoscopic data on normal swallowing physiology were generated. These data may serve as an accurate benchmark for clinicians and researchers in the interpretation of dysphagia.

Anatomy and physiology of feeding and swallowing: normal and abnormal

Eating and swallowing are complex behaviors involving volitional and reflexive activities of more than 30 nerves and muscles. They have two crucial biologic features: food passage from the oral cavity to stomach and airway protection. The swallowing process is commonly divided into oral, pharyngeal, and esophageal stages, according to the location of the bolus. The movement of the food in the oral cavity and to the oropharynx differs depending on the type of food (eating solid food versus drinking liquid). Dysphagia can result from a wide variety of functional or structural deficits of the oral cavity, pharynx, larynx, or esophagus. The goal of dysphagia rehabilitation is to identify and treat abnormalities of feeding and swallowing while maintaining safe and efficient alimentation and hydration.

Respiration during feeding on solid food: alterations in breathing during mastication, pharyngeal bolus aggregation, and swallowing

During feeding, solid food is chewed and propelled to the oropharynx, where the bolus gradually aggregates while the larynx remains open and breathing continues. The aggregated bolus in the valleculae is exposed to respiratory airflow, yet aspiration is rare in healthy individuals. The mechanism for preventing aspiration during bolus aggregation is unclear. One possibility is that alterations in the pattern of respiration during feeding could help prevent inhalation of food from the pharynx. We hypothesized that respiration was inhibited during bolus aggregation in the valleculae. Videofluorography was performed on 10 healthy volunteers eating solid foods with barium. Respiration was monitored concurrently with plethysmography and nasal air pressure. The timing of events during mastication, food transport, pharyngeal bolus aggregation, and swallowing were measured in relation to respiration. Respiratory cycle duration decreased during chewing (P < 0.001) but increased with swallowing (P < 0.001). During 66 recordings of vallecular bolus aggregation, there was inspiration in 8%, expiration in 41%, a pause in breathing in 17%, and multiple phases (including inspiration) in 35%. Out of 98 swallows, 47% started in the expiratory phase and 50% started during a pause in breathing, irrespective of bolus aggregation in the valleculae. Plethysmography was better than nasal manometry for determining the end of active expiration during feeding and swallowing with solid food. The hypothesis is rejected in that respiration was not inhibited during bolus aggregation. These findings suggest that airflow through the pharynx does not have a role in preventing aspiration during bolus aggregation in the oropharynx.

Temporal sequence of swallow events during the oropharyngeal swallow

PURPOSE

To (a) identify and characterize the temporal relation of selected structural movements during the oropharyngeal swallow across participants, (b) determine whether patterns of movement could be identified, and (c) determine whether the temporal relations were affected by aging and bolus characteristics.

METHOD

Retrospective analysis of videofluoroscopic swallows of 100 normal participants (age range=22-92 years) was conducted. Two swallows each of 3-ml and 10-ml liquids and a 1-3-ml paste bolus were analyzed. The onset of a number of structural movements and bolus arrival points were compared against a single reference event: onset of upper esophageal sphincter (UES) opening.

RESULTS

Normal participants demonstrated predominant sequences in pharyngeal movement patterns with some variability. The use of voluntary swallow maneuvers by these normal participants accounted for some degree of this variability. Volume, consistency, and age all affected the temporal relation between onset of specific motor events relative to the onset of UES opening. Increasing bolus volume was associated with a shorter temporal difference between UES opening and onset of other pharyngeal movements. In contrast, a thicker bolus was associated with longer temporal differences. Younger participants generally demonstrated shorter temporal differences between events than did older participants.

CONCLUSION

Temporal relations between structural movements are not fixed but can be systematically affected by bolus characteristics and age.

Timing of glottic closure during swallowing: a combined electromyographic and endoscopic analysis

OBJECTIVES

We performed a case series to enhance our understanding of the coupling between neuromuscular events and glottic closure.

METHODS

We performed combined flexible video laryngoscopy and electromyography in 4 healthy human subjects. Hooked-wire electrodes were placed in the superior pharyngeal constrictor, longitudinal pharyngeal, cricopharyngeus, thyroarytenoid, genioglossus, suprahyoid, and posterior cricoarytenoid muscles. A flexible endoscope tip was positioned in the oropharyngeal-hypopharyngeal region. The subjects performed multiple trials each of 10-mL normal and super-supraglottic liquid swallows.

RESULTS

Arytenoid movement consistently preceded full glottic closure and was associated with cessation of activity of the posterior cricoarytenoid muscle. In 89% of normal swallows, the glottis was partially open in the video frame before bolus passage. The maximum amount of thyroarytenoid electromyographic activity occurred during endoscopic whiteout. When subjects executed a super-supraglottic swallow, early thyroarytenoid activity coincided with arytenoid contact.

CONCLUSIONS

The initial medialization of the arytenoids is due to a decrease in motor tone of the posterior cricoarytenoid muscle. Full glottic closure typically occurs late in the process of swallowing, with activation of the thyroarytenoid muscle. Shifting of arytenoid medialization and glottic closure earlier in the super-supraglottic swallow indicates that glottic closure is under significant voluntary control.

Nutritional challenges in head and neck cancer

In head and neck cancer patients malnutrition impacts on quality of life, complications of therapy and also prognosis, in part via altered immunity. Dysphagia assessment is extremely valuable but more work is needed to optimize the rehabilitation of the incompetent swallow in this particular patient group. Proper nutritional assessment is mandatory pre-/peri-/post-treatment. The range and palatability of nutritional supplements has greatly increased over the past few years. Many of the early problems of percutaneous gastrostomy feeding have been addressed but complication rates still remain high. As accelerated radiotherapy and chemoradiation techniques become more widely advocated, nutrition is likely to become increasingly important. The authorship includes two otolaryngologists, a nutritionist and a speech and language therapist with an interest in head and neck dysphagia, thereby aiming to provide a broad perspective of these issues. However, there appears to be a lack of prospective evaluation of many aspects of dysphagia/nutrition in head and neck cancer, which needs to be addressed.

Sequence variability during hypopharyngeal bolus transit

The pharyngeal phase of deglutition is considered to occur in a reflexive, preprogrammed fashion. Previous studies have determined a general sequence of events based on the mean timing of bolus transit and swallowing gestures. Individual variability has not been studied, however. The purpose of this study was to determine the amount of sequence variability that normally occurs during the hypopharyngeal phase of deglutition. Dynamic swallow studies from 60 normal volunteers were evaluated and event sequence variability was determined for 12 two-event sequences during swallowing of three bolus sizes. There was found to be some variability in event sequences for almost all events evaluated except for the following: (1) arytenoid cartilage elevation always began prior to opening of the upper esophageal sphincter, (2) the sphincter always opened prior to the arrival of the bolus at the sphincter, (3) larynx-to-hyoid approximation always occurred after the onset of upper esophageal sphincter opening, and (4) maximum pharyngeal constriction always occurred after maximal distension of the upper esophageal sphincter. Variability was more common during swallowing of the smallest bolus size. This information may be helpful in evaluating event coordination in patients with dysphagia.

Oropharyngeal swallow in younger and older women: videofluoroscopic analysis

Much of the initial research on normal swallowing has been conducted in young men. Recently, there has been increasing interest in determining whether there are differences between the sexes in swallowing function and in the effects of aging on swallowing in both sexes. This investigation examined the swallowing ability of 8 healthy young women between the ages of 21 and 29 and 8 healthy older women between the ages of 80 and 93 during two swallows each of 1 ml and 10 ml liquid boluses. Videofluoroscopic studies of these swallows were reviewed in slow motion and real time to confirm the absence of swallowing disorders. Kinematic analysis of each swallow was completed. Data on range of motion of pharyngeal structures and coordination characteristics of the oropharyngeal swallow were taken from this kinematic analysis. Position of the larynx at rest and length of neck were compared between the two groups. Data from this study were compared with previously published data on younger and older men. Interestingly, the range of motion of the older women was often greater than that of the young women. Only tongue base movement diminished significantly with age in women. Volume effects observed in duration and extent of movement during the 1 ml and 10 ml swallows were similar to those in earlier studies. Older women also exhibited an increased range of motion relative to the old men. This increase may indicate a compensation for aging effects not seen in older men.

Oropharyngeal swallowing variability

OBJECTIVES/HYPOTHESIS

The pharyngeal phase of deglutition is considered to occur in a reflexive, preprogrammed fashion. Previous studies have determined a general sequence of events based on the mean timing of bolus transit and swallowing gestures. However, individual variability has not been studied. The purpose of the present study was to evaluate the amount of sequence variability that normally occurs during the oropharyngeal phase of deglutition.

STUDY DESIGN

Prospective analysis of conservative subjects.

METHODS

Dynamic swallow studies from 60 normal volunteers were evaluated, and event sequence variability was determined around two event sequences during swallowing of three bolus sizes.

RESULTS

There was found to be substantial variability in event sequences for all events analyzed. Variability was greater during a smaller bolus swallow.

CONCLUSIONS

The evaluation of variability within the study group of individuals reveals the complexity of the swallowing mechanism and underscores the importance of not relying on general guidelines in evaluating the coordination of swallowing gestures in a given individual with dysphagia complaints.

Accommodation to changes in bolus viscosity in normal deglutition: a videofluoroscopic study

Videofluoroscopic swallow studies were performed on 60 normal adult volunteers. Swallowing variables were measured during swallows of a 3-cm3 paste bolus and a 3-mL liquid bolus and were compared to identify changes in swallow gesture displacement and timing, as well as changes in bolus movement timing. The study revealed that some differences measured by videofluoroscopy appear to be the result of the inherent bolus characteristics, while others likely represent changes in swallow gestures needed to accommodate variations in bolus viscosity. The overall timing of pharyngeal transit did not vary between bolus types. Oropharyngeal transit trended toward being faster for a liquid bolus with a concurrent early elevation of the aryepiglottic folds. The hyoid bone elevated at the same time, at the same rate, and to the same extent irrespective of bolus viscosity. During a liquid bolus swallow, the hyoid bone trended toward a more prolonged elevation, corresponding to prolonged pharyngoesophageal sphincter opening. The pharyngoesophageal sphincter, however, opened to a greater extent with a paste bolus.

Swallowing in myotonic muscular dystrophy: a videofluoroscopic study

OBJECTIVES

(1) To determine how swallow function in patients with myotonic muscular dystrophy (MD) differs from that of healthy controls, (2) to identify the contributors to and predictors of improvement, and (3) to evaluate strategies that facilitate swallowing.

DESIGN

Observational.

SETTING

University medical center.

PARTICIPANTS

Eighteen adults with myotonic MD (age range, 24-58 yr) and 60 healthy adult control subjects (age range, 18-73 yr).

INTERVENTIONS

Swallow facilitation strategies.

MAIN OUTCOME MEASURES

Between-group comparisons of mean bolus transit times, onsets of swallow gestures, and displacement measures obtained by dynamic lateral view videofluoroscopy.

RESULTS

The MD patients' bolus transit times were significantly longer, and onsets of some swallow gestures were significantly delayed. Upper esophageal sphincter opening was prolonged (myotonic MD,.61 +/-.13s; control,.5 +/-.11s). Hyoid displacement was significantly less in men with myotonic MD (1.9 +/-.05 cm) than in male controls (2.4 +/-.68 cm); this difference was not observed between control and myotonic women. Of particular importance was the markedly reduced pharyngeal constriction found in the MD group.

CONCLUSIONS

Weakness associated with the disease, as opposed to myotonia, was the most significant contributor to impairment. Persons at risk for aspiration may be identified by a measure of pharyngeal area. Selected strategies to facilitate pharyngeal clearing are worthwhile.

Study of movements of individual structures of the larynx during swallowing

OBJECTIVE

The purpose of this study was to reveal movements of individual structures of the larynx during swallowing.

METHODS

Subjects were 7 healthy adults, aged 24 to 32 years (average 27 years), who had no organic or functional disease of the pharynx and larynx and 2 adults with unilateral recurrent nerve palsy, aged 49 and 60 years, respectively. We used the Toshiba IIDR system, which is composed of an X-ray TV system and a digital image managing circuit. One-fifth diluted Omnipark 300 was used as contrast medium (lohexol), with 15 cc for each swallow. The mask image for subtraction was designated as the frame before laryngeal elevation during swallowing for subtraction. We obtained the images for observation and analysis after subtracting the mask image from continuously obtained images. These images were captured into a personal computer at 30 frames per s and thereafter frame-by-frame observation and analysis were performed by means of NIH image 1.56.

RESULTS

We observed that the vocal folds underwent a series of movements during swallowing. (1) They adduct slowly and do not ascend; (2) then begin to ascend and continue adducting; whereby (3) they abduct for a moment while ascending. (4) Again, they adduct and achieve closure. (5) While maintaining closure, vocal folds elevate further to reach their maximal elevation; and (6) begin to abduct rapidly while maintaining maximal elevation. Finally, (7) they begin to descend and undergo repeated irregular abduction and adduction while descending. In examining the relationship between closure and opening at levels of the vocal fold and false vocal fold, we found that closure at the false vocal fold level precedes that at the vocal fold level and that opening at the vocal fold level precedes that at the level of the false vocal fold.

CONCLUSION

Closure of the false vocal fold level appears important in the protection of the lower respiratory tract during swallowing.

Chronic intermittent stimulation of the thyroarytenoid muscle maintains dynamic control of glottal adduction

Patients with laryngeal motor control disorders need improved dynamic glottal closure for speech and swallowing. To evaluate the functional outcome of intermittent chronic thyroarytenoid muscle stimulation in an animal model, 6 canines were implanted with bilateral Medtronic Xtrel systems containing Peterson-type electrodes in the inferior and superior portions of the thyroarytenoid muscle. Stimulation was on one side only at 60 Hz, for 5 s on and 5 s off, over 8 h, 5 days per week, up to 8 months. Monthly videorecordings were done under anesthesia to measure the voltage threshold for detectable movement on each side, and vocal fold displacement and velocity during maximal stimulation of each side. Movement thresholds were lower in the inferior portion of the thyroarytenoid muscle (P </= 0.0005). Movement velocity was greater on the stimulated than on the nonstimulated side after 3 to 8 months (P = 0.039). No differences in the percentage distribution of different myosin heavy chain types were found between the stimulated and nonstimulated muscle samples. Sustained dynamic glottal adduction with no alteration in thyroarytenoid muscle function or fiber type was achieved with intermittent stimulation over 8 months. The results suggest that chronic intermittent thyroarytenoid stimulation has good potential for improving airway protection in dysphagia.

Age and volume effects on liquid swallowing function in normal women

Understanding the nature of swallowing in persons without swallowing problems is a prerequisite to evaluating the nature and extent of dysphagia in persons with compromised swallowing. In order to determine how swallowing varies with age and with liquid bolus volume in women, we assessed 167 normal female swallowers videofluoroscopically and obtained multiple measures of swallowing function. The women in this study demonstrated a change in swallowing function with age, due primarily to an increase in pharyngeal transit and total duration of the motor response. The duration of closure and opening of valves in the upper aerodigestive tract also increased with age, and the duration of laryngeal elevation and hyoid movement peaked in the 60-79-year-old age groups. Bolus volume effects were quite consistent across most measures. As the bolus volume increased from 1 ml to 10 ml, transit times decreased and durations of valve closure and opening increased. The results of this study may be used to specify the relationship of swallowing function to age and liquid bolus volume in women, relationships that heretofore have been observed only in part and in smaller and more heterogeneous populations.

A prospective, double-blind, randomized study on the use of a topical anesthetic, vasoconstrictor, and placebo during transnasal flexible fiberoptic endoscopy

The purpose of the present study was to compare patient comfort levels following administration of a topical anesthetic, vasoconstrictor, placebo, or nothing to the nasal mucosa prior to flexible fiberoptic transnasal endoscopy. Using a prospective, double-blind, randomized design, 152 consecutive patients were randomly assigned to receive a topical anesthetic (N = 54), vasoconstrictor (N = 50), or placebo (N = 48). No significant differences were found among the three variables. An additional 50 consecutive patients had endoscopy performed without administration of any substance to the nares, and no significant differences were found among the four variables (N = 202). It was concluded that speech-language pathologists can perform independent and comfortable transnasal endoscopy without administration of any substance to the nasal mucosa. Flexible fiberoptic endoscopy, however, should be performed by experienced clinicians with care taken to examine visually the patency of both nares for ease and comfort of scope insertion.

Swallowing disorders in head and neck cancer patients treated with radiotherapy and adjuvant chemotherapy

The nature of swallowing problems was examined in nine patients treated primarily with external-beam radiation and adjuvant chemotherapy for newly diagnosed tumors of the head and neck. All subjects underwent videofluorographic examination of their swallowing. Three analyses were completed, including the following: observations of motility disorders, residue, and aspiration; temporal analyses; and biomechanical analyses. Oropharyngeal swallow efficiency was calculated for the first swallow of each bolus. Swallow motility disorders were observed in both the oral and pharyngeal stages. Seven of the nine patients demonstrated reduced posterior tongue base movement toward the posterior pharyngeal wall and reduced laryngeal elevation during the swallow. Oropharyngeal swallow efficiency measures were significantly lower in the nine irradiated patients than in age-matched normal subjects. Between patients and normal subjects, significant differences were found in the measures of timing and distance of pharyngeal structural movements during the swallow, as well as in the measures of coordination during the swallow. Although treatment of head and neck cancer with external-beam radiation is designed to provide cancer cure and preserve organ functioning, oral and pharyngeal motility for swallow can become compromised if external-beam radiation treatment is provided to either the larynx or tongue base regions.