Radiographic Magnification on Videofluoroscopy: An Important Variable to Consider for Scaled Analyses of Swallowing.

PURPOSE: Traditionally, kinematic measures on videofluoroscopy require the use of an external scalar (such as a penny) to transform pixels to absolute distances. Videofluoroscopy is subject to image magnification based on the distance of the feature of interest to the X-ray source. However, the impact of the position/location of the external scalar on swallowing measures is unknown. Our goal was to systematically investigate the accuracy of various common external scalar locations in lateral and anterior-posterior (A-P) view. METHOD: U.S. pennies were taped to a styrofoam head in three positions (on the left and right lateral neck and in midline submentally). Locations were measured to ensure equal left and right, as well as midline, placement. A metal screwdriver (6 mm in diameter) was inserted into the premanufactured hole that is centrally located at the bottom of the styrofoam head. The head was centered on a medical tray and placed in the middle of a Siemens Alpha C-arm Fluoroscope field. ImageJ was used to measure penny length in pixels (three locations) in both lateral and A-P views. Penny length was known (19.05 mm), and, therefore, used to derive screwdriver size (for each location) for comparison to the actual screwdriver size. RESULTS: All scalars overestimated the screwdriver size ranging from 6.55 to 7.87 mm, representing a 9%-31% inflation. Scalars closer to the X-ray source had the largest magnification. CONCLUSIONS: Our results confirm that image magnification of external scalars is a significant source of variability that is currently unaccounted for in the swallowing literature. Recommendations for future research design/measurement methods are provided.

A scoping review of the methods used to capture dysphagia after anterior cervical discectomy and fusion: the need for a paradigm shift.

OBJECTIVE: Dysphagia is the most commonly reported complication of annterior cervical discectomy and fusion (ACDF) surgery. However, the incidence of dysphagia post-ACDF varies widely-partly attributable to differing outcome measures used to capture dysphagia. Our objective was to conduct a scoping review of the literature to quantify which dysphagia outcome measures have been employed post-ACDF and examine trends by study design, year, and location. METHODS: After removing duplicates, 2396 abstracts were screened for inclusion. A total of 480 studies were eligible for full-text review. After applying exclusion criteria, data was extracted from 280 studies. We extracted the dysphagia outcome measure(s), study design (prospective vs retrospective), year, and location (country). Approximately 10% of studies were repeated for intra-rater agreement. RESULTS: In total, 317 dysphagia outcome measures were reported in 280 studies (primarily retrospective-63%). The largest proportion of outcome measures were categorized as "unvalidated patient-reported outcome measures" (46%), largely driven by use of the popular Bazaz scale. The next most common categories were "insufficient detail" and "validated patient-reported outcome measures" (both 16%) followed by "chart review/database" (13%) and instrumental assessment (7%). Studies examining dysphagia post-ACDF steadily increased over the years and the use of validated measures increased in the past 10 years. CONCLUSIONS: This scoping review of the literature highlights that nearly half of the ACDF dysphagia literature relies on unvalidated patient-reported outcome measures. The current understanding of the mechanism, timeline, and presentation of dysphagia post-ACDF are likely limited due to the metrics that are most commonly reported in the literature.

Perception of Swallowing-Related Fatigue Among Older Adults.

PURPOSE: Although fatigue is recognized as clinically relevant to swallowing performance, its prevalence and significance in dysphagic and nondysphagic adults have not been sufficiently examined. In this study, an online survey was used to examine swallowing- and eating-related fatigue (SERF) symptoms, the relationship between perceived SERF and other dysphagia-related health outcomes, and whether perceived SERF predicts risk for dysphagia or malnutrition. METHOD: An online survey of older adults (aged 60 years or older) was conducted. A novel 12-item scale was developed to capture perceived SERF. Previously validated scales were used to measure dysphagia risk, sarcopenia, general fatigue, malnutrition risk, and quality of life. Logistic regression was used to examine whether SERF predicted risk for dysphagia and/or malnutrition. RESULTS: Complete responses were collected from 417 community-dwelling adults (M age = 70.6 years, SD = 4.9; 263 women); 75% (n = 312) reported at least some degree of SERF. SERF was significantly correlated with dysphagia risk, sarcopenia, general fatigue, malnutrition risk, and quality of life. SERF was a significant predictor of dysphagia risk while controlling for age, gender, and other health outcomes (odds ratio [OR] = 1.2, 95% confidence interval [CI; 1.16, 1.27], p < .001). For every unit increase in SERF score, the odds of being at risk for dysphagia were associated with an increase of 22%. Significant predictors for malnutrition risk included SERF (OR = 0.94, 95% CI [0.91, 0.98]), general fatigue (OR = 0.95, 95% CI [0.92, 0.99]), and quality of life (OR = 1.04, 95% CI [1.0, 1.1]). CONCLUSIONS: Fatigue during swallowing and mealtimes is experienced by community-dwelling older adults and predicted dysphagia risk and malnutrition risk. Further research is needed to refine and validate a patient-reported outcome measure for SERF and examine the effects of fatigue on swallowing function and physiology under imaging. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.20405835.

The relationship between sarcopenia, dysphagia, malnutrition, and frailty: making the case for proactive swallowing exercises to promote healthy aging.

PURPOSE OF REVIEW: The purpose of this review is to summarize current evidence regarding the relationship between sarcopenia of the swallowing muscles, dysphagia, malnutrition, and frailty in the context of aging. Further, this review will provide preliminary support for proactive swallowing exercises to reverse and/or prevent sarcopenia of the swallowing muscles. RECENT FINDINGS: Recent studies lend support to a cyclic relationship between sarcopenia of the swallowing muscles, dysphagia, malnutrition, and frailty. Unfortunately, all studies are limited by their study design and lack instrumental imaging of swallowing function. Research (in the limbs) supports the use of proactive exercises and protein supplementation to reverse sarcopenia, especially in prefrail individuals. This provides a foundation to design and test similar preventive exercises for the swallowing muscles. SUMMARY: As the population is rapidly aging, it is vital to understand how the natural loss of muscle in aging impacts swallowing function and the downstream impact on nutritional and physical function. Prospective, longitudinal research with sophisticated outcome measures are required to fully understand this cycle and provide an opportunity to test methods for interrupting the cycle.

Survey of Clinician Perspectives and Practices Regarding Swallowing-Related Fatigue.

Introduction Fatigue is commonly identified by clinicians who evaluate and treat swallowing impairment despite a lack of research in this area. The purpose of this study was to understand the current role of swallowing-related fatigue in dysphagia evaluation with respect to (a) clinician practices, (b) perspectives, and (c) desire for resources regarding swallowing-related fatigue. Method A survey was conducted by licensed speech-language pathologists who evaluate and treat adult dysphagia. The survey was distributed via dysphagia-focused groups on Facebook and Special Interest Group 13. Data were analyzed descriptively and by thematic analysis for free-text response questions. Results Out of 426 prospective respondents, 311 completed the survey (response rate = 73.0%). While 86% of respondents agreed that fatigue may be a concern for individuals with swallowing impairment, there was wide variability in how clinicians define and evaluate swallowing-related fatigue, and the majority (62%) define fatigue in two or more ways. Explicit evaluation of fatigue was reportedly conducted by 45% of respondents during the Clinical Swallowing Evaluation, by 38% during videofluoroscopic swallowing study, and by 53% during Flexible Endoscopic Evaluation of Swallowing. The most common methods for identifying fatigue were general declines in performance over the course of the assessment. Respondents reported much more reliance on patient report during Clinical Swallowing Evaluation (41%) compared to videofluoroscopic swallowing study (7%) and fiberoptic endoscopic evaluation of swallowing (5%). Only 7% of respondents reported being aware of any standardized methods for assessing fatigue, while 97% of respondents affirmed interest in incorporating standardized methods for assessing swallow-related fatigue. Conclusions Our results demonstrated wide variability in how currently practicing clinicians define and evaluate swallowing-related fatigue, despite the vast majority considering fatigue to be an important factor in dysphagia evaluation. This study highlights a critical gap in the clinical evaluation of swallowing and requires significant further study to guide clinical practice.

Correction to: Volumetric Changes to the Pharynx in Healthy Aging: Consequence for Pharyngeal Swallow Mechanics and Function.

This erratum notifies the readers of the Dysphagia journal of an error in the original published version of this manuscript. In that manuscript, a previously available open source spreadsheet tool was used to calculate the position of the posterior laryngeal air column on lateral view videofluoroscopic images as a proxy for the bottom of the pharynx. We have subsequently been made aware of an error in the mathematical formula built into the spreadsheet, which resulted in a reversal of the results for the X and Y planes of measurement. This erratum provides corrections to the results and interpretations of the original manuscript.

Correction to: Assessing Hyolaryngeal Excursion: Comparing Quantitative Methods to Palpation at the Bedside and Visualization During Videofluoroscopy.

This letter notifies the readers of the Dysphagia journal of an error in the original published version of this manuscript, for which a previously available open source spreadsheet tool had been used to calculate the position of the hyoid bone or larynx on lateral view videofluoroscopic images. An error in the mathematical formula built into the spreadsheet resulted in a reversal of the results for the X and Y planes of measurement. This erratum provides corrections to the results and interpretations of the original manuscript.

Measuring Hyoid Excursion Across the Life Span: Anatomical Scaling to Control for Variation.

Purpose A method for controlling for sex-based differences in measures of hyoid movement using an internal anatomical scalar has been validated in young healthy individuals. Known anatomical changes with aging necessitate validation of this methodology in a mixed-age sample. The primary aim of this study was to validate a method for controlling for sex-based differences in measures of hyoid movement across the life span. Measurement error as a potential source of variability was addressed to inform best practice recommendations. Method Two distinct data sets previously collected using identical protocols were combined for this study to achieve a data set of young (< 40 years) and older (> 65 years) healthy adults. Data included videofluoroscopic swallow studies with three swallow trials each of 5 and 20 ml thin liquid barium. Previously reported methodology was replicated to validate the use of an anatomical scalar for measuring hyoid excursion in this sample. Hyoid movement was measured using 2 methods (rest-to-peak displacement and peak only) in 3 planes of movement (anterior, superior, and hypotenuse), was expressed in millimeters and individually scaled units relative to C4, and normalized using the C2-C4 vertebral distance. Mixed-model repeated-measures analyses of variance were run with each of the 6 hyoid measures as the dependent variable (in both millimeters and C2-C4 units), within-subject factors of sex and bolus volume, and a between-subjects factor of age group. We predicted that the C2-C4 scalar would adequately control for sex-based differences across age groups. Results Significant differences in absolute hyoid movements (millimeters) were observed by sex, bolus volume, and age group. When measured in %C2-C4 units, all differences between males and females were neutralized. Significant differences between 5- and 20-ml boluses were found for all peak position measures. Significant differences between young and older individuals were found for all peak position measures. Conclusion Expressing hyoid excursion as a percentage of the C2-C4 distance appears valid for use across the life span. Peak position is preferable over displacement measures for quantifying hyoid excursion for research and clinical purposes.

Establishing a method for quantifying spinal curvature during videofluoroscopic swallow studies: Applying the modified Cobb angle to healthy young and older adults.

The Cobb angle is traditionally used for quantifying the degree of spinal curvature through evaluation of the full spinal cord. When conducting measurements on videofluoroscopy swallowing studies (VFSS), the Cobb angle can measure degree of cervical vertebrae curvature, which may have implications for swallowing. Given that this measure may have utility in dysphagia research, the reliability of this measure taken from C2-C4 and establishing the presence of changes with age were the focus of the current, proof-of-principle study. VFSS from 19 healthy young adults and 39 healthy older adults were retrospectively analyzed. The C2-C4 Cobb angle was measured between cervical vertebrae two and four on frames of laryngeal vestibule closure (LVC) and post-swallow rest. Results revealed excellent levels of inter- and intra-rater reliability for frame of post-swallow rest (ICCs = 0.788 and 0.793), and fair to good levels of agreement for frame of LVC (ICCs = 0.667 and 0.621). Significant differences in the C2-C4 Cobb angle were found between the healthy young and old data (p < 0.01). Healthy younger adults had a mean angle of 5.8±9.0 degrees at LVC and 7.7±4.5 degrees at swallow rest, whereas healthy older adults had a mean angle of 12.5±9.0 degrees at LVC and 12.4±9.7 degrees at rest. Consistent with the existing spine literature, the curvature of cervical vertebrae appears to increase with age. With established reliability, we propose that the C2-C4 Cobb angle may be used to determine the degree of spinal curvature in a variety of patient populations in order to determine impacts on swallowing function.

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

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

Physiological Compensation for Advanced Bolus Location at Swallow Onset: A Retrospective Analysis in Healthy Seniors.

Purpose Previous work has established that advanced bolus location at swallow onset (BLSO) alone is not correlated with an increased swallowing safety risk in healthy seniors. The primary goal of this retrospective study was to examine whether healthy seniors systematically alter their laryngeal vestibule closure reaction time (LVCrt) to maintain a safe swallow in the context of advanced BLSO. The secondary goal was to determine if longer LVCrt distinguished Penetration-Aspiration Scale (PAS; Rosenbek, Robbins, Roecker, Coyle, & Wood, 1996) scores of 1 versus 2. Method Videofluoroscopy studies from 43 healthy seniors (21 men, 22 women; M age = 76.7 years, SD = 7.2) were analyzed. LVCrt was calculated for 3 × 5 ml and 3 × 20 ml thin liquid barium boluses per participant. PAS and BLSO (Modified Barium Swallow Impairment Profile Component 6) were scored for all swallows. Reliability (intraclass correlation coefficient > .75) was established on all measures. A linear mixed-effects regression was run to examine the effect of PAS and BLSO on LVCrt while controlling for bolus volume and repeated swallow trial. Results There was a main effect of BLSO (F = 4.6, p = .004) and PAS (F = 29.3, p < .001) on LVCrt. Post hoc pairwise comparisons revealed that LVCrt was significantly faster in BLSO scores of 3 (pyriforms) compared to scores of both 0 (posterior angle of the ramus) and 1 (valleculae). Significantly prolonged LVCrt was observed in PAS scores of 2 in comparison to 1. No significant main effects of bolus volume or trial, or interactions, were observed. Conclusions Our findings suggest that healthy seniors compensate for advanced BLSO by increasing their LVCrt. Furthermore, faster LVCrt was shown to distinguish PAS scores of 1 versus 2. Additional work should explore the relationship between LVCrt, BLSO, and PAS scores in dysphagic populations, specifically those with known sensory impairments.

An intensive swallowing exercise protocol for improving swallowing physiology in older adults with radiographically confirmed dysphagia.

PURPOSE: The aim of this study was to investigate improvements in swallowing function and physiology in a series of healthy older adults with radiographically confirmed dysphagia, following completion of an exercise-based swallowing intervention. PATIENTS AND METHODS: Nine otherwise healthy older adults (six females, mean age =75.3, SD =5.3) had confirmed impairments in swallowing safety and/or efficiency on a modified barium swallow study. Each participant completed an 8-week swallowing treatment protocol including effortful swallows, Mendelsohn maneuvers, tongue-hold swallows, supraglottic swallows, Shaker exercises and effortful pitch glides. Treatment sessions were conducted once per week with additional daily home practice. Penetration-Aspiration Scale and the Modified Barium Swallowing Impairment Profile (MBSImP) were scored in a blind and randomized fashion to examine changes to swallowing function and physiology from baseline to post-treatment. RESULTS: There were significant improvements in swallowing physiology as represented by improved oral and pharyngeal composite scores of the MBSImP. Specific components to demonstrate statistical improvement included initiation of the pharyngeal swallow, laryngeal elevation and pharyngeal residue. There was a nonsignificant reduction in median PAS scores. CONCLUSION: Swallowing physiology can be improved using this standardized high-intensity exercise protocol in healthy adults with evidence of dysphagia. Future research is needed to examine the individual potential of each exercise in isolation and to determine ideal dose and frequency. Studies on various etiological groups are warranted.

Assessing Hyolaryngeal Excursion: Comparing Quantitative Methods to Palpation at the Bedside and Visualization During Videofluoroscopy.

PURPOSE: Hyolaryngeal excursion (HE) is typically assessed via palpation during clinical swallowing exams (CSE) or visually during videofluoroscopy (VFSS). Minimal evidence exists to support the use of these perceptual methods for judging HE. We investigated whether binary judgment of HE differentiates quantitative measures of hyoid movement, using frame-by-frame VFSS analysis to measure anatomically scaled peak hyoid positions. METHODS: Medical records of patients who received a CSE and VFSS within a 24-h period were reviewed. Clinician ratings of HE ('reduced' or 'normal') were collected from CSE and VFSS reports, along with rater experience. Five ml puree swallows were extracted from each VFSS for randomized, blinded analysis. Peak hyoid position from C4 was captured in anterior, superior, and hypotenuse positions and expressed relative to C2-C4 length. T-test comparisons of hyoid positions between patients judged to have reduced versus normal HE on palpation and VFSS were conducted. RESULTS: Eighty-seven patients (56 male, mean age 61) met criteria. Peak anterior hyoid position was significantly different between patients judged to have reduced (mean = 89.2% C2-C4) and normal (mean = 110.6% C2-C4) HE on palpation (p = 0.001). Further analysis revealed no effect of clinician experience on differentiation of objective measures based on palpation. No differences were found across any objective measures when compared to clinician VFSS ratings. CONCLUSIONS: Clinicians appeared to be able to differentiate peak anterior hyoid movement but not superior or hypotenuse movement on palpation. On VFSS visualization, no significant differences were found between swallows judged to have reduced versus normal HE in any directional dimension. While perceptual methods may contribute to clinical decision-making, clinicians should remain cautious when making judgments about HE using these methods.

Volumetric Changes to the Pharynx in Healthy Aging: Consequence for Pharyngeal Swallow Mechanics and Function.

Pharyngeal lumen volume is prone to increase as a consequence of pharyngeal muscle atrophy in aging. Yet, the impact of this on swallowing mechanics and function is poorly understood. We examined the relationship between pharyngeal volume and pharyngeal swallowing mechanics and function in a sample of healthy community-dwelling seniors. Data were collected from 44 healthy seniors (21 male, mean age = 76.9, SD = 7.1). Each participant swallowed 9 boluses of barium (3 × 5 ml thin, 3 × 20 ml thin, 3 × 5 ml nectar). Pharyngeal shortening, pharyngeal constriction, pyriform sinus and vallecular residue were quantified from lateral view videofluorosopic swallowing studies. Pharyngeal lumen volume was captured during an oral breathing task with acoustic pharyngometry. In addition, within-participant measures of strength and anthropometrics were collected. Four linear mixed effects regression models were run to study the relationship between pharyngeal volume and pharyngeal constriction, pharyngeal shortening, pyriform sinus residue, and vallecular residue while controlling for bolus condition, age, sex, and posterior tongue strength. Increasing pharyngeal lumen volume was significantly related to worse constriction and vallecular residue. In general, larger and thicker boluses resulted in worse pharyngeal constriction and residue. Pharyngeal shortening was only significantly related to posterior tongue strength. Our work establishes the utility of acoustic pharyngometry to monitor pharyngeal lumen volume. Increasing pharyngeal lumen volume appears to impact both pharyngeal swallowing mechanics and function in a sample of healthy, functional seniors.

Analysis of pharyngeal edema post-chemoradiation for head and neck cancer: Impact on swallow function.

OBJECTIVES: Edema is a frequent clinical observation following chemoradiation treatment (CRT) of oral/oropharyngeal cancer and is thought to contribute to post-CRT swallowing impairment. Our aims were to reliably quantify pharyngeal edema pre- and post-CRT from videofluoroscopic (VF) swallowing studies and to explore the relationship between edema and swallowing impairment. Swallowing impairment was captured using patient-reported swallowing outcomes (EAT-10) and with VF confirmation of impairment (DIGEST). METHODS: 40 patients (24 M, age 38-76) with oral/oropharyngeal cancer received radiotherapy (70 Gy, 7 weeks) and 3 weekly doses of cisplatin. VF and EAT-10 were completed pre- and 1-month post-CRT. Edema was captured by measuring posterior pharyngeal wall (PPW) thickness, vallecular space, and pharyngeal area (PA) on a single post-swallow rest frame. Wilcoxon sign rank tests and paired t-tests evaluated within-subject changes in impairment and edema respectively. A linear mixed effect regression model explored the influence of time, patient-reported outcomes, and functional impairment on measures of edema. RESULTS: Swallowing function (EAT-10 and DIGEST) was significantly worse post-CRT. PPW thickness (but not vallecular space and pharyngeal area) was significantly worse post-CRT. PPW thickness was only significantly influenced by time (pre- vs. post-CRT) but not by measures of swallow function. CONCLUSION: Our findings establish the use of PPW thickness as a reliable measure of acute edema in post-CRT treatment. In this small, retrospective sample, edema was not significantly correlated with either patient-reported or measured swallow function. Prospective longitudinal work, examining the relationship between objective measures of edema, patient perception of impairment, and swallow function and biomechanics is warranted. LEVEL OF EVIDENCE: 4.

The Swallowing Profile of Healthy Aging Adults: Comparing Noninvasive Swallow Tests to Videofluoroscopic Measures of Safety and Efficiency.

Purpose: It has been widely reported that a proportion of healthy, community-dwelling seniors will develop dysphagia in the absence of a known neurological, neuromuscular, or structural cause. Our objective was to test whether various feasible, noninvasive measures of swallowing could differentiate safe versus unsafe and efficient versus inefficient swallowing on videofluoroscopy (VF) in a sample of healthy seniors. Method: VFs from 44 (21 male, 23 female) healthy community-dwelling seniors (> 65 years old) were compared with a series of feasible, noninvasive swallowing metrics: maximal tongue strength (anterior and posterior), hand grip strength, pharyngeal volume, age, body mass index, 3-oz water swallow challenge, the 10-item Eating Assessment Tool questionnaire, and the Frailty Index. The VF protocol included 9 liquid barium boluses (3 × 5 ml thin, 3 × 20 ml thin, and 3 × 5 ml nectar). Each swallow was rated (randomized and blind) for safety using the Penetration-Aspiration Scale score and for efficiency using the Normalized Residue Ratio Scale (NRRS). Participants were deemed "unsafe" if they had any single Penetration-Aspiration Scale scores ≥ 3 and "inefficient" if they had any NRRS valleculae score > 0.082 or NRRS pyriform sinus score > 0.067. Univariate analyses of variance were run for each continuous swallowing measure by swallowing safety and swallowing efficiency status. Pearson's chi-square analyses were used to compare binary outcomes by swallow safety and efficiency status. Bonferroni corrections were applied to control for multiple comparisons. Results: None of the swallowing measures significantly differentiated safe from unsafe swallows. Although several variables trended to distinguishing efficient from inefficient swallows (age, 10-item Eating Assessment Tool, 3-oz water swallow challenge), only one variable, pharyngeal volume, was significantly different between efficient and inefficient swallows (p = .002). Conclusion: Our findings support the notion that larger pharyngeal volumes (measured using acoustic pharyngometry) are associated with worse swallowing efficiency, a finding we attribute to atrophy of the pharyngeal musculature in healthy aging.

Swallow Event Sequencing: Comparing Healthy Older and Younger Adults.

Previous research has established that a great deal of variation exists in the temporal sequence of swallowing events for healthy adults. Yet, the impact of aging on swallow event sequence is not well understood. Kendall et al. (Dysphagia 18(2):85-91, 2003) suggested there are 4 obligatory paired-event sequences in swallowing. We directly compared adherence to these sequences, as well as event latencies, and quantified the percentage of unique sequences in two samples of healthy adults: young (< 45) and old (> 65). The 8 swallowing events that contribute to the sequences were reliably identified from videofluoroscopy in a sample of 23 healthy seniors (10 male, mean age 74.7) and 20 healthy young adults (10 male, mean age 31.5) with no evidence of penetration-aspiration or post-swallow residue. Chi-square analyses compared the proportions of obligatory pairs and unique sequences by age group. Compared to the older subjects, younger subjects had significantly lower adherence to two obligatory sequences: Upper Esophageal Sphincter (UES) opening occurs before (or simultaneous with) the bolus arriving at the UES and UES maximum distention occurs before maximum pharyngeal constriction. The associated latencies were significantly different between age groups as well. Further, significantly fewer unique swallow sequences were observed in the older group (61%) compared with the young (82%) (χ2 = 31.8; p < 0.001). Our findings suggest that paired swallow event sequences may not be robust across the age continuum and that variation in swallow sequences appears to decrease with aging. These findings provide normative references for comparisons to older individuals with dysphagia.

Alterations to Swallowing Physiology as the Result of Effortful Swallowing in Healthy Seniors.

A significant proportion of healthy seniors report difficulty swallowing, thought to result from age-related decline in muscle bulk/function. Effortful Swallowing (ES) is used both as a compensatory maneuver to improve pharyngeal propulsion/clearance and has been proposed as an exercise to improve pharyngeal strength. This study sought to quantify the immediate kinematic, temporal, and functional changes during an ES maneuver to quantify its exercise potential to combat age-related changes in swallowing. Videofluoroscopy data were collected from 44 healthy seniors (21 male) over 65 years old (mean = 76.9, SD = 7.1). Each participant swallowed six 5 ml boluses of Varibar nectar-thick liquids: three with regular effort and three using ES. Individual swallows (n = 260) were measured on pharyngeal constriction, pharyngeal shortening, laryngeal closure duration, hyoid movement duration, UES opening duration, stage transition duration, pharyngeal transit time, pharyngeal response duration, Normalized Residue Ratio Scale (NRRS), and the Penetration-Aspiration Scale (PAS). Non-parametric Wilcoxon Rank Sum for repeated measures tested the effect of ES on each outcome. Exact p-values were calculated based on permutation methods, individual p values < 0.008 was deemed to be significant. The ES maneuver significantly prolonged all temporal variables. While we found no significant differences for pharyngeal constriction, significantly less (i.e., worse) pharyngeal shortening was observed in ES condition compared with regular effort swallows. Further, significantly worse pyriform sinus residue (NRRSv) was observed in the ES condition. No differences between ES and regular effort swallows were noted for pharyngeal constriction, NRRSv or PAS. We speculate that these negative manifestations of worse kinematics (less pharyngeal shortening) and function (increase in NRRSp) may be the result of forced volitional manipulation of swallowing in the ES condition in an otherwise normal elderly swallow.

The Reliability of Oral and Pharyngeal Dimensions Captured with Acoustic Pharyngometry.

Acoustic Pharyngometry (APh) is a method for quantifying oropharyngeal tract configuration using sound wave reflection and is commonly used in diagnostics and research of sleep apnea. The standard preset output of APh (minimal cross-sectional area) has been established as reliable. However, by conducting post-processing measures on specific breathing tasks, APh data can also reveal oral length, oral volume, pharyngeal length, and pharyngeal volume. Given that these measures may have utility in dysphagia research, the reliability of these measures is unknown and is the focus of the current study. Ten young healthy female volunteers completed two sessions of APh data collection to obtain measures of oral length, oral volume, pharyngeal length, and pharyngeal volume 1 week apart. Two-way mixed intraclass correlation coefficients were calculated to establish intra-rater reliability, inter-rater reliability, and test-retest reliability. Results revealed excellent levels of agreement within and across raters for all oropharyngeal tract parameters. Levels of test-retest agreement for oral length and oral volume indicated these parameters are appropriate for monitoring change within an individual. All parameters were deemed to have acceptable test-retest values as outcome measures in group-level analysis.

The Effect of Bolus Consistency on Hyoid Velocity in Healthy Swallowing.

The aim of this study was to determine whether measures of hyoid velocity increase when swallowing liquids of thicker consistency at a constant volume. A gender-balanced sample of 20 healthy young participants (mean age 31.5) each swallowed 3 boluses of 5 ml volume in 3 consistencies (ultrathin, thin, and nectar-thick barium). Using frame-by-frame tracking of hyoid position, we identified the onset and peak of the hyoid movement and derived measures of velocity (i.e., distance in anatomically normalized units, i.e., % of the C2-4 vertebral distance, divided by duration in ms) for the X, Y, and XY movement directions. Peak hyoid velocity was also identified for each movement direction. Where significant differences were identified, the component measures of hyoid movement distance and duration were further explored to determine the strategies used to alter velocity. The results showed increased velocities and higher peak velocities with the nectar-thick stimuli compared to thin and ultrathin stimuli. This was achieved by a primary strategy of larger hyoid movement distances per unit of time when swallowing nectar-thick liquids. These results point to one mechanism by which thickened liquids may contribute to improved airway protection by facilitating more timely laryngeal vestibule closure.