Faculty Bibliography

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.

PURPOSE/OBJECTIVE:We quantified pharyngeal residue using pixel-based methods in a normative data set, while examining influences of age, gender, and swallow task. METHOD/METHODS:). Logistic regression models explored predictors of residue versus no residue. Generalized linear mixed models explored predictors of nonzero residue. Spearman rho explored relationships between ASPEKT total residue scores and MBSImP Component 16 (Pharyngeal Residue) scores. RESULTS:per year). As ASPEKT total residue values increased, MBSImP Component 16 scores also increased. CONCLUSIONS:Pharyngeal residue amounts were very low in healthy adults. Residue presence can be influenced by age, gender, and swallow task. However, when present, the amount of pharyngeal residue was only associated with increasing age. SUPPLEMENTAL MATERIAL/BACKGROUND:https://doi.org/10.23641/asha.21957221.

PURPOSE OF REVIEW/OBJECTIVE: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/RESULTS: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/CONCLUSIONS: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.

Fatigue is widely accepted as a clinically relevant factor in the diagnosis, treatment, and management of dysphagia. Despite the relative importance that is placed on swallowing-related fatigue, the occurrence and effects of fatigue during swallowing is unclear. The goal of this study was to explore effects of eating a meal on measures of tongue strength, endurance, and other parameters of swallowing function under normal conditions compared to when the tongue is intentionally fatigued. Thirty healthy females, 15 "Young" (18-35 years old), and 15 "Old" (70 + years old) were seen for two data collection sessions one week apart. On both days, pre-meal measures were collected, then participants consumed a standardized meal based on a previously published protocol (half a bagel with peanut butter and 8 baby carrots) followed by post-meal measures. An additional pre-meal fatigue task was included on one of the test days (counterbalanced), involving maximal tongue presses until participants could not achieve 40% of baseline maximum pressure. Pre- and post-meal measures included anterior and posterior maximum tongue pressures, saliva swallow pressure, tongue endurance, surface electromyography (sEMG), the modified Borg scale, and the Test of Mastication and Swallowing of Solids (TOMASS). Linear mixed effects regressions compared pre- and post-meal outcome measures (1) on the non-fatigue day and (2) between fatigue and non-fatigue days while controlling for participant and age. The fatigue task caused significant reductions in maximum anterior and posterior tongue pressure. After a normal meal (i.e., without fatigue), we found decreased anterior pressures in the older group only. Older participants also had decreased saliva swallow pressures after the meal compared to pre-meal, while this measure increased post-mean in the young participants. When compared to the non-fatigue meal, eating a meal after tongue fatigue resulted in significantly lower post-meal posterior pressures, regardless of age group. The same pattern was observed with posterior functional reserve. Our results demonstrate that a systematic, participant-specific tongue fatigue task induced measurable changes in maximum tongue pressure. A meal by itself was observed to reduce anterior tongue strength and saliva swallow pressures only in older participants. Overall, it appears that older adults may be more vulnerable to fatigue-induced changes in tongue strength, though the relationship between these measures and changes to functional swallowing remains unknown.

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.

Bolus properties such as volume, consistency, and density have been shown to influence swallowing through the analysis of kinematics and timing in both normal and disordered swallowing. However, inherent intra- and inter-person variability of swallowing cloud interpretation of group data. Computational analysis of swallow mechanics (CASM) is an established methodology that uses coordinate tracking to map structural movements during swallowing and yields statistically powerful analyses at both the group and individual levels. In this study, the CASM method was used to determine how different bolus properties (volume, consistency, and density) altered swallow mechanics in healthy young adults at the group and individual levels. Videofluoroscopic swallow studies of 10 (4 females) healthy young adults were analyzed using CASM. Five bolus types were administered in each study (3 × 5 ml 40% w/v nectar, 3 × 5 ml 22% w/v thin, 3 × 5 ml 40% w/v thin, 3 × 10 ml 22% w/v thin, and 3 × 20 ml 22% w/v thin). Canonical variate analyses demonstrated that bolus condition did not affect swallowing mechanics at the group level, but bolus condition did affect pharyngeal swallow mechanics at the individual level. Functional swallow adaptations (e.g., hyoid movement) to bolus conditions were not uniform across participants, consistent with the nonsignificant group finding. These results suggest that individual swallowing systems of healthy young individuals vary in how they respond to bolus different conditions, highlighting the intrinsic variability of the swallow mechanism and the importance of individually tailored evaluation and treatment of swallowing. Findings warrant further investigation with different bolus conditions and aging and disordered populations.

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

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.

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.

PURPOSE/OBJECTIVE: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.