Alterations in Swallowing Six Weeks After Primary Anterior Cervical Discectomy and Fusion (ACDF)

This aim of this study is to characterize the nature and pathophysiology of dysphagia after ACDF surgery by precisely and comprehensively capturing within-subject changes on videofluoroscopy between preoperative and postoperative time points. 21 adults undergoing planned primary ACDF procedures were prospectively recruited and enrolled. Participants underwent standardized preoperative and six-week postoperative videofluoroscopic swallow studies. Videos were blindly rated using the Penetration-Aspiration Scale (PAS) and analysis of total pharyngeal residue (%C2-42), swallowing timing, kinematics, and anatomic change was completed. Linear mixed-effects modeling was used to explore the relationships between possible predictor variables and functional outcomes of interest that changed across timepoints. There was no change in PAS scores across timepoints. Total pharyngeal residue (%C2-C42) was increased postoperatively (p < 0.001). Our statistical model revealed significant main effects for timepoint (p = 0.002), maximum pharyngeal constriction area (MPCAN) (p < 0.001), and maximum thickness of posterior pharyngeal (PPWTMAX) (p = 0.004) on the expression of total pharyngeal residue. There were significant two-way interactions for timepoint and MPCAN (p = 0.028), timepoint and PPWTMAX (p = 0.005), and MPCAN and PPWTMAX (p = 0.010). Unsurprisingly, we found a significant three-way interaction between these three predictors (p = 0.027). Our findings suggest that in planned ACDF procedures without known complications, swallowing efficiency is more likely to be impaired than airway protection six weeks after surgery. The manifestation of impaired swallowing efficiency at this timepoint appears to be driven by a complex relationship between reduced pharyngeal constriction and increased prevertebral edema.

Quantifying Pharyngeal Residue Across the Adult Life Span: Normative Values by Age, Gender, and Swallow Task

PURPOSE

We quantified pharyngeal residue using pixel-based methods in a normative data set, while examining influences of age, gender, and swallow task.

METHOD

One hundred ninety-five healthy participants underwent a videofluoroscopic swallow study following the Modified Barium Swallow Impairment Profile (MBSImP) protocol. ImageJ was used to compute Normalized Residue Ratio Scale and the Analysis of Swallowing Physiology: Events, Kinematics and Timing (ASPEKT) pharyngeal residue measures. Reliability was established. Descriptive statistics were performed for all residue measures. Inferential statistics were performed using ASPEKT total scores (i.e., %C2-42). 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

Majority of swallows (1,165/1,528; 76.2%) had residue scores of zero. Residue presence (%C2-42 > 0) was influenced by age (more in older [F = 9.908, p = .002]), gender (more in males [F = 18.70, p < .001]), viscosity (more in pudding, nectar, and honey [F = 25.30, p < .001]), and volume (more for cup sip [F = 37.430, p < .001]). When residue was present (363/1,528 = 23.8%), amounts were low (M = 1% of C2-42, SD = 2.4), and only increasing age was associated with increased residue (F = 9.008, p = .007) when controlling for gender and swallow task. Increasing residue was incremental (0.01% of C2-42 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

https://doi.org/10.23641/asha.21957221.

The Influence of Age, Eating a Meal, and Systematic Fatigue on Swallowing and Mealtime Parameters

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.

Predictors of Residue and Airway Invasion in Parkinson's Disease

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

Variations in Healthy Swallowing Mechanics During Various Bolus Conditions Using Computational Analysis of Swallowing Mechanics (CASM)

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.

A Cross-Sectional Evaluation of Wellness in New York City Community-Dwelling Seniors (P01-035-19)

Objectives

The older adult population is increasing worldwide, placing significant burden on healthcare and support systems. Meeting nutrition and physical activity guidelines is critical to maintain health and quality of life (QOL). The objective of this study was to assess nutrition, swallowing, body composition, and physical function in community-dwelling seniors (CDSs) and describe the prevalence of poor status.

Methods

CDSs (n = 54; 42 female; age = 80.1 ± 6.7; body mass index [BMI] = 25.2 ± 4.1 kg/m2) participated in a wellness visit to assess a) nutrition (Dietary Screening Tool [DST], an instrument that identifies nutritional risk), b) swallowing (90 ml water swallow challenge; EAT-10 swallowing screening tool) c) body composition (waist circumference; calf circumference; body fat mass index [BFMI]; fat-free mass index [FFMI]), and d) physical function (SARC-F, a five item sarcopenia screener; Short Physical Performance Battery [SPPB], testing balance, gait speed, and sit to stand). Height was measured using a portable stadiometer; weight with a Seca digital scale. Waist and calf circumferences were measured in triplicate. Body composition was assessed via bioelectrical impedance analysis using the Quad Scan 4000 multifrequency analyzer (BodyStat). BFMI (fat mass, kg/[height, m]2) and FFMI (fat-free mass, kg/[height, m]2) were determined.

Results

The DST revealed that 11(20.4%) and 35(64.8%) of the CDSs were “at risk” and “possible risk” for poor nutritional status, respectively. Although the EAT-10 documented swallowing difficulties in 5(9.3%) of the CDSs, 12 (22.2%) failed the 90 ml water swallow challenge, consistent with risk of swallowing impairment. Excess adiposity was found in 31(57.4%) using waist circumference and 30(55.6%) using BFMI. Low muscle mass, captured by FFMI, was found in 35(64.8%) of the CDSs. Calf circumference values revealed malnutrition in 3(5.6%) of the CDSs. Six (11.1%) of the CDSs had SARC-F scores associated with poor physical function indicating significant muscle loss in aging. Similarly, SPPB results revealed 14(25.9%) had poor lower extremity physical function.

Conclusions

CDSs exhibit impairments in these measures of wellness, placing their health and QOL at risk. Research examining the impact of lifestyle interventions on these measures is needed.

Funding Sources

None

Changes in Swallowing After Anterior Cervical Discectomy and Fusion With Instrumentation: A Presurgical Versus Postsurgical Videofluoroscopic Comparison

PURPOSE

The purpose of this study was to explore the impact of anterior cervical discectomy and fusion (ACDF) with anterior instrumentation on swallowing function and physiology as measured on videofluoroscopic swallowing studies.

METHOD

We retrospectively analyzed both functional measures (penetration-aspiration, residue) and physiological/anatomical measures (hyoid excursion, posterior pharyngeal wall thickness) in a series of 17 patients (8 men, 9 women, mean age 54 years). These measures were extracted from calibrated 5-ml boluses of thin radio-opaque liquids on both pre-ACDF and post-ACDF videofluoroscopies, thus controlling for individual variation and protocol variation.

RESULTS

After ACDF surgery, we found significant within-subject worsening of Penetration-Aspiration Scale (Rosenbek, Robbins, Roecker, Coyle, & Wood, 1996) scores, vallecular (but not piriform sinus) residue, superior (but not anterior) hyoid excursion, and posterior pharyngeal wall thickness. Results are discussed in the context of previous literature.

CONCLUSIONS

ACDF surgery can affect both physiological/anatomical and functional measures of swallowing. Future research should expand to other biomechanical and temporal variables, as well as greater bolus volumes and a wider array of viscosities and textures.