Impaired swallowing mechanics of post radiation therapy head and neck cancer patients: A retrospective videofluoroscopic study

Improved NTCP model for late radiation-induced aspiration based on dose delivered to specific aspiration-related OARs

BACKGROUND AND PURPOSE

Radiation-induced aspiration is a serious complication following (chemo)radiation for head and neck cancer. The standard set of swallowing organs at risk (SWOARs) does not include all aspiration-related organs (OARs). An alternative proposed in earlier work includes a definition and delineation atlas for additional OARs, called Functional Swallowing Units (FSU). The purpose of this study was to compare two NTCP models for late aspiration, based on either SWOARs only or the FSU concept.

METHODS AND MATERIALS

Data from 189 patients were analysed. Aspiration at baseline (Asp_T0) and 6 months after treatment (Asp_T6) were scored according to Penetration Aspiration Scale (PAS). All SWOARs and FSUs were delineated and the DVH was recorded. Clinical factors and average dose (Dmean) to all aspiration-related OARs were included in multivariable analysis. Two models were built, model 1: including clinical factors and SWOARs only and model 2: including clinical factors, SWOARs and FSUs.

RESULTS

Both final models included Asp_T0 and Dmean to the supraglottic larynx as predictors. Model 2 included the dose to three additional OARs as a predictor: 1) Anterior Segment (floor of mouth/ thyrohyoid muscles) 2) hyoglossus/styloglossus muscles complex (HSG) 3) upper oesophageal sphincter (UES). Adding FSUs to model 1 resulted in significant model updates and model 2 performed better than model 1 (AUC 0.79 vs. 0.75).

CONCLUSION

NTCP models for late aspiration may be improved by including the dose to aspiration-related OARs, defined by the FSU concept. In addition to the supraglottic larynx, sparing of the Anterior Segment, HSG and UES could further decrease the risk of radiation-induced aspiration, but this remains to be confirmed in clinical studies.

Swallowing Function Outcomes in Head and Neck Cancer Survivors Followed by a Long-Term Dysphagia Surveillance Protocol

BACKGROUND

This study aimed to evaluate swallow outcomes in head and neck cancer (HNC) survivors enrolled in a long-term dysphagia surveillance protocol following curative intent radiotherapy (RT).

METHODS

We conducted a retrospective review of videofluoroscopic swallow studies from 2015 to 2023 in HNC patients treated with RT. Swallow kinematics and function were assessed at baseline, 0-1, 1-2, 2-5, and 5+ years post-RT. Logistic regression models assessed kinematic deviations beyond 2SD from normative and dichotomized outcomes.

RESULTS

Among 638 patients with 1167 VFSS, 14.6% were 2 years post-RT, primarily oral cavity (29.6%) and oropharyngeal (46.7%) cancers treated with adjuvant (chemo) RT (53.3%). At 2 years, 51.3% exhibited abnormal hyolaryngeal movement, 27.5% had pharyngeal contraction abnormalities, and 9.0% had impaired pharyngoesophageal opening. Unsafe swallow was seen in 51.6% with moderate-to-profound dysphagia in 45%.

CONCLUSION

Dysphagia surveillance revealed significant swallowing impairments in HNC survivors, with unsafe swallowing prevalent in over half of cases 2 years post-RT.

Food texture modification in head and neck cancer patients: a scoping review

The aim of this study was to provide an overview of food texture modification to address dysphagia in patients with head and neck cancer, and the current application of these methods. A comprehensive search strategy was developed across five databases: PubMed, Embase, Web of Science Core Collection, CINAHL, and the Cochrane Library. The JBI guidance for scoping reviews was used to conduct a descriptive analysis of the literature and extract data. Thirteen studies were included; 11 evaluated swallowing function in patients undergoing treatment for HNC, while two directly investigated modified food in relation to swallowing function in patients treated for HNC. Most of the studies used thin liquids for assessment, and the evaluation process often transitioned from thin or thick liquids to solids/semi-solids. Adverse outcomes occurred regardless of the treatment. However, dysphagia seemed to get worse in the short term after surgery. In terms of interventions, thickeners might have a positive effect on the patient's swallowing function. In the studies investigating food texture modification, there was an increased incidence of adverse swallowing outcomes after therapeutic treatment. Further intervention with thickener could be considered in this patient population, and a comprehensive approach needs to be taken throughout the treatment process.

Maximum Vocal Pitch Elevation and Swallowing: A Secondary Data Analysis Supporting Additional Shared Biomechanics and Potential Treatment Targets

PURPOSE

Reduced ability to raise vocal pitch has been associated with risk of aspiration in some populations. However, the mechanisms driving this association are understudied. This secondary data analysis aims to add to our knowledge on the shared and distinct biomechanics of swallowing and maximum vocal pitch elevation.

METHOD

We used existing data from the study of Venkatraman et al. (2020) on 10 healthy younger (age range: 19-23, M = 21) and eight older (age range: 65-79; M = 73) adults who completed maximum pitch elevation and swallow tasks under videofluoroscopy. A MATLAB tracking tool and computational analysis of swallowing mechanics was used to analyze five elements of pharyngeal swallowing biomechanics (anterior and superior hyoid excursion, laryngeal elevation, pharyngeal shortening, tongue base retraction, head/neck extension). Canonical variate analysis (CVA) determined differences associated with task and age. Post hoc discriminant function analyses (DFAs) compared the events between tasks in each group.

RESULTS

CVA revealed that 63.9% of variance was accounted for by task (D = 3.46, p < .0001) and 35.5% by age (D = 1.92, p < .0001). Across age, DFAs indicated similar anterior hyoid excursion and laryngeal elevation between tasks, but greater superior hyoid excursion during swallows, replicating earlier findings. We also found greater base of tongue retraction during swallows than maximum pitch and greater pharyngeal shortening during maximum pitch elevation compared to swallows across groups (D = 5.38, p < .0001).

CONCLUSIONS

Maximum pitch elevation and swallowing require similar anterior hyoid and laryngeal excursion. Added to the novel finding of greater pharyngeal shortening during pitch elevation, we indicate that pitch glides may be a mechanism for targeting pharyngeal dysphagia and warrant further investigation.

Using Sequence Analyses to Quantitatively Measure Oropharyngeal Swallowing Temporality in Point-of-Care Ultrasound Examinations: A Pilot Study

(1) Background: Swallowing is a complex process that comprises well-timed control of oropharyngeal and laryngeal structures to achieve airway protection and swallowing efficiency. To understand its temporality, previous research adopted adherence measures and revealed obligatory pairs in healthy swallows and the effect of aging and bolus type on the variability of event timing and order. This study aimed to (i) propose a systemic conceptualization of swallowing physiology, (ii) apply sequence analyses, a set of information-theoretic and bioinformatic methods, to quantify and characterize swallowing temporality, and (iii) investigate the effect of aging and dysphagia on the quantified variables using sequence analyses measures. (2) Method: Forty-three participants (17 young adults, 15 older adults, and 11 dysphagic adults) underwent B-mode ultrasound swallowing examinations at the mid-sagittal plane of the submental region. The onset, maximum, and offset states of hyoid bone displacement, geniohyoid muscle contraction, and tongue base retraction were identified and sorted to form sequences which were analyzed using an inventory of sequence analytic techniques; namely, overlap coefficients, Shannon entropy, and longest common subsequence algorithms. (3) Results: The concurrency of movement sequence was found to be significantly impacted by aging and dysphagia. Swallowing sequence variability was also found to be reduced with age and the presence of dysphagia (H(2) = 52.253, p < 0.001, η2 = 0.260). Four obligatory sequences were identified, and high adherence was also indicated in two previously reported pairs. These results provided preliminary support for the validity of sequence analyses for quantifying swallowing sequence temporality. (4) Conclusions: A systemic conceptualization of human deglutition permits a multi-level quantitative analysis of swallowing physiology. Sequence analyses are a set of promising quantitative measurement techniques for point-of-care ultrasound (POCUS) swallowing examinations and outcome measures for swallowing rehabilitation and evaluation of associated physiological conditions, such as sarcopenia. Findings in the current study revealed physiological differences among healthy young, healthy older, and dysphagic adults. They also helped lay the groundwork for future AI-assisted dysphagia assessment and outcome measures using POCUSs. Arguably, the proposed conceptualization and analyses are also modality-independent measures that can potentially be generalized for other instrumental swallowing assessment modalities.

Relationship Between Pharyngeal Residues Assessed by Bolus Residue Scale or Normalized Residue Ratio SCALE and Risk of Aspiration in Head and Neck Cancer Who Underwent Videofluoroscopy

Dysphagia affects 60-75% of patients treated for head and neck cancer (HNC). We aimed to evaluate the association between residue severity and airway invasion severity using a videofluoroscopic swallowing study and identify risk factors for poor penetration-aspiration outcomes in patients with dysphagia treated for HNC. Penetration-Aspiration Scale (PAS) was used to assess airway invasion severity, while residue severity was assessed using both the Bolus Residue Scale (BRS) for residue location and the Normalized Residue Ratio Scale (NRRS) for residue amount. Relevant covariates were adjusted in the logistic regression models to account for potential confounding. Significantly higher abnormal PAS was reported for increased piriform sinus NRRS (NRRSp) [odds ratio (OR), 4.81; p = 0.042] with liquid swallowing and increased BRS value (OR, 1.52; p = 0.014) for semi-liquid swallowing in multivariate analysis. Tumor location, older age, and poorer Functional Oral Intake Scale (FOIS) were significant factors for abnormal PAS in both texture swallowings. After adjusting for confounding factors (sex, age, and FOIS score), NRRS model in liquid swallowing (area under the curve [AUC], 0.83; standard error = 0.04, 95% confidence interval [CI]: 0.75, 0.91) and BRS in semi-liquid swallowing (AUC, 0.83; SE = 0.04; 95% CI: 0.76, 0.91) predicted abnormal PAS. The results indicate that while assessing residue and swallowing aspiration in patients with HNC, it is important to consider age, tumor location, and functional swallowing status. The good predictability of abnormal PAS with BRS and NRRS indicated that residue location and amount were both related to the aspiration event in patients with HNC.

Evaluation of chronological changes in videofluorographic findings after transoral videolaryngoscopic surgery to reveal mechanism of dysphagia

OBJECTIVES

Transoral surgery preserves good swallowing function in most cases, however, postoperative dysphagia sometimes leads to fatal complication such as aspiration pneumonia. We investigated the chronological changes in swallowing function have not been revealed relationship with dysphagia. The primary aim of this study was to reveal the mechanism of dysphagia following transoral surgery by analyzing chronological videofluorography (VF) findings. Moreover, the secondary aim of this study was to evaluate the relationship between mechanism of dysphagia and risk factors of patients to clarify the risk for dysphagia lead to prevention of postoperative complications.

METHODS

22 patients who underwent transoral videolaryngoscopic surgery (TOVS) for either supraglottic or hypopharyngeal cancer were evaluated swallowing function. We performed VF during the preoperative, postoperative acute, and stable phases and investigated the chronological changes in the VF findings. The following parameters were evaluated by VF: horizontal distance of laryngeal movement, vertical distance of laryngeal elevation, laryngeal elevation delay time (LEDT), Bolus Residue Scale (BRS) scores, and Penetration Aspiration Scale (PAS) scores. Additionally, we evaluated risk factors for postoperative aspiration by investigating relationships between preoperative VF parameters, age of patients, history of radiation therapy, resection area, tumor (T) stage, postoperative Numeric Rating Scale (NRS), and PAS and BRS scores.

RESULTS

The median time at which oral feeding was resumed in this study was 9 (2-200) days. The patients who had postoperative acute PAS scores of 4 and above exhibited delays in resuming oral ingestion after surgery. TOVS did not impair laryngeal elevation and LEDT; however, the BRS and PAS scores temporarily worsened in the acute phase compared to the preoperative scores. These scores almost recovered to their preoperative states in the stable phase, and both the BRS and PAS scores worsened and recovered concurrently. Patients who exhibited poor vertical distance in laryngeal elevation as observed via preoperative VF or who had histories of radiation therapy had worse PAS scores in postoperative acute phase VF. Patients with broad resection areas had worse BRS scores in postoperative acute phase VF.

CONCLUSION

TOVS didn't impair the function of laryngeal elevation and elicitation of the swallowing reflex whereas pharyngeal bolus clearance, laryngeal penetration, and aspiration temporarily deteriorated concurrently but eventually almost recovered to their baseline values. Patients with histories of radiotherapy, poor laryngeal elevation, and broad resection areas are at the risk of postoperative dysphagia after TOVS. Patients with these risk factors need appropriate evaluation before resuming postoperative oral intake.

Longitudinal Analysis of Swallowing Displacement Kinematics After Oropharyngeal Cancer Treatment

BACKGROUND/OBJECTIVE

Quantitative swallowing displacement kinematics evolve in patients treated for oropharyngeal squamous cell carcinoma (OPSCC). We aimed to longitudinally assess these measurements and correlate them with functional swallowing outcomes.

METHOD

A retrospective review was conducted on patients with OPSCC treated with definitive (chemo)radiation ([C]RT) or surgery with adjuvant (chemo)radiation (S-[C]RT) who completed at least two videofluoroscopic swallow studies (VFSS). Longitudinal analysis was accomplished via mixed-effects logistic regression for the Functional Oral Intake Scale (FOIS), and Penetration Aspiration Scale (PAS), and mixed-effects linear regression for kinematic measures. Spearman's correlation was conducted between changes in FOIS/PAS and kinematic measures.

RESULTS

Ninety-seven patients (76 males; mean age 61) completed 245 VFSS studies. A total of 94% had human papillomavirus (HPV)/p16 positive OPSCC and 74% were T0-T2. Sixty-four patients underwent [C]RT while 33 patients underwent S-[C]RT. After treatment, posterior pharyngeal wall at hold (PPWhold) increased 3.2 standard deviation (SD) between 0 and 6 months (p < 0.001), then decreased 2.2 SD between 6 and 12 months (p < 0.001) and did not return to baseline. Hyoid-to-larynx (HL) (p = 0.046) and maximal hyoid displacement (Hmax) + HL (p = 0.042) increased between 6 and 12 months. Hmax (p = 0.020) and Hmax + HL (p < 0.001) decreased between 12-24 months beyond baseline values. The decrease in HL and increase in PPWhold (p < 0.05) correlated with an increase in PAS. From baseline, increased pharyngeal constriction ratio correlated with decreased FOIS and PPWhold (p < 0.05).

CONCLUSIONS

Quantitative swallowing kinematic measures can effectively track changes in swallowing physiology. Increased PPWhold and restricted hyolaryngeal movement were seen in patients with OPSCC after treatment and correlated with a change in swallowing outcome, emphasizing the need for serial VFSS monitoring and targeted intervention.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

Influence of handgrip strength on pharyngeal transit time in individuals with chronic obstructive pulmonary disease

OBJECTIVE

To investigate the relationship between Handgrip Strength (HGS), dysphagia classification, nutritional aspects, and Pharyngeal Transit Time (PTT) in subjects with Chronic Obstructive Pulmonary Disease (COPD).

METHODS

Study based on the analysis of secondary data from a database. The sample comprised 15 COPD patients of both sexes and a mean age of 65.7 years. We collected information on HGS, videofluoroscopic swallowing study, Volume-Viscosity Swallow Test (V-VST), and Body Mass Index (BMI). We applied correlation, effect size, and logistic regression tests at the 5% significance level.

RESULTS

Most individuals had severe COPD (66.7%), mean dominant HGS of 28.2, and non-dominant HGS of 25.3. Five subjects were malnourished, five were well-nourished, and five were obese. Most of them had normal swallowing (40%), normal V-VST results (60%), and PTT of 0.89 s (liquid) and 0.81 s (pudding-thick). There was no significant correlation between the swallowing classification and the other variables. We obtained a significant correlation (p = 0.015), though weak (r = -0.611), between non-dominant HGS and PTT. Regarding the binary logistic regression, HGS variables and HGS asymmetry were not enough to be considered a risk to clinically abnormal swallowing (V-VST).

CONCLUSION

Subjects with COPD in this study had a longer PTT than reported in the literature for normal subjects and a weak correlation between PTT and non-dominant HGS. The variables related to muscle condition were not considered predictors for abnormal swallowing.

LEVEL OF EVIDENCE: 3

Functional swallowing outcomes related to radiation exposure to dysphagia and aspiration-related structures in patients with head and neck cancer undergoing definitive and postoperative intensity-modulated radiotherapy

BACKGROUND

The relationship between swallowing outcomes and radiotherapy dose to dysphagia and aspiration-related structures (DARS) may be different following definitive versus postoperative radiotherapy (PORT) for mucosal head and neck cancer (HNC) and has not been well-studied.

METHOD

Patient- and clinician-reported swallowing measures were prospectively collected at six time points from baseline to 24 months postradiotherapy HNC. Radiotherapy plans were retrospectively analyzed to assess dose delivered to DARS. The association between swallowing outcomes and participant demographics, tumor characteristics, and radiotherapy dose in definitive and postoperative treatment cohorts was assessed.

RESULTS

Ninety-three participants who received radiotherapy for HNC were included in the analysis (n = 49 definitive radiotherapy for laryngeal/pharyngeal primary tumors and n = 44 postoperative PORT for predominantly oral cavity/salivary gland tumors). Participants undergoing PORT had lower doses to DARS than those undergoing definitive RT. High dose to the pharyngeal constrictors and base of tongue for definitive RT and the esophageal inlet, supraglottic larynx and cervical esophagus for the PORT group were associated with worse swallowing function.

CONCLUSION

Radiation dose to DARS is associated with post-treatment swallowing outcomes. These dose/outcome relationships may vary between the definitive and postoperative settings.

Swallowing, nutritional status, and salivary flow in patients after head and neck cancer treatment, a pilot study

Determine the relationship between swallowing function, nutritional status, and salivary flow in patients after head and neck cancer treatment. This pilot study included 17 patients. Swallowing was assessed through videofluoroscopy and surface electromyography (sEMG), nutritional status through anthropometry and dietary assessment, and salivary flow both with and without mechanical stimulation. Test analysis showed that 66.7% of patients had functional limitations in swallowing in 58.3%, 66.7%, and 58.3% residue scale with an average of a line of barium on a structure for pudding, honey, and liquid consistencies, respectively. Laryngeal penetration was found in 8.3% during the swallowing of liquid. Surface electromyography (sEMG) showed above normal values for muscle activity time during the swallowing of pudding. Anthropometric assessment and muscle and adipose tissue indicated eutrophy. Salivary flow test with mechanical stimulus showed that 82.3% of patients' salivary production was well below the appropriate level. There was a significant correlation between muscle tissue reserve and muscle activity time during swallowing in the studied muscles (left masseter p = 0.003, right masseter p = 0.001, suprahyoid p = 0.001, orbicularis oris = 0.020), all in pudding consistency. This pilot study confirmed the relationship between swallowing and nutritional status for its participants, showing that appropriate protein intake influences muscle activity during swallowing in head and neck cancer survivors.

Respiratory-swallow coordination in a rat model of chemoradiation

BACKGROUND

Chemoradiation treatment (CRT) for head and neck cancer (HNC) is associated with postswallow inhale events that elevate the risk of penetration/aspiration. The purpose of this study was to assess the validity of a rat model for investigating the effect of CRT on respiratory-swallow coordination.

METHODS

Videofluoroscopic swallow study was performed on 10 Sprague-Dawley rats 3 months post-CRT (3 mg/kg Cisplatin, 10 fractions of 4.5 Gy/day radiotherapy to tongue base), and 10 naïve controls. We examined the effect of CRT on swallow apnea duration, diaphragm movement, and bolus kinematics.

RESULTS

CRT rats had a significant increase in postswallow inhale (p = 0.008), which was associated with significantly longer swallow apnea durations, lower diaphragm displacement at swallow onset, and faster pharyngoesophageal bolus speed.

CONCLUSION

The rat CRT model is valid for the study of respiratory-swallow coordination due to the consistency of findings in this study with those reported in clinical CRT studies in HNC.

Determining the Impact of Thickened Liquids on Swallowing in Patients Undergoing Irradiation for Oropharynx Cancer

The current standard for the treatment of oropharynx cancers is radiation therapy. However, patients are frequently left with dysphagia characterized by penetration-aspiration (impaired safety) and residue (impaired efficiency). Although thickened liquids are commonly used to manage dysphagia, we lack evidence to guide the modification of liquids for clinical benefit in the head and neck cancer population. The objective of this study was to assess the impact of slightly and mildly thick liquids on penetration-aspiration and residue in 12 patients with oropharyngeal cancer who displayed penetration-aspiration on thin liquid within 3 to 6 months after completion of radiotherapy. Significantly fewer instances of penetration-aspiration were seen with slightly and mildly thick liquids as compared with thin (P < .05). No differences were found across stimuli in the frequency of residue. Patients with oropharyngeal cancers who present with post-radiation therapy dysphagia involving penetration-aspiration on thin liquids may benefit from slightly and mildly thick liquids without risk of worse residue.

The Relationships Between Radiation Dosage and Long-term Swallowing Kinematics and Timing in Nasopharyngeal Carcinoma Survivors

This study aimed to investigate the relationship between intensity-modulated radiation therapy (IMRT) dosimetry and swallowing kinematic and timing measures. Thirteen kinematic and timing measures of swallowing from videofluoroscopic analysis were used as outcome measures to reflect swallowing function. IMRT dosimetry was accessed for thirteen swallowing-related structures. A cohort of 44 nasopharyngeal carcinoma (NPC) survivors at least 3 years post-IMRT were recruited. The cohort had a mean age of 53.2 ± 11.9 years, 77.3% of whom were male. There was an average of 68.24 ± 14.15 months since end of IMRT; 41 (93.2%) had undergone concurrent chemotherapy. For displacement measures, female sex and higher doses to the cricopharyngeus, glottic larynx, and base of tongue were associated with reduced hyolaryngeal excursion and pharyngeal constriction, and more residue. For timing measures, higher dose to the genioglossus was associated with reduced processing time at all stages of the swallow. The inferior pharyngeal constrictor emerged with a distinctly different pattern of association with mean radiation dosage compared to other structures. Greater changes to swallowing kinematics and timing were observed for pudding thick consistency than thin liquid. Increasing radiation dosage to swallowing-related structures is associated with reduced swallowing kinematics. However, not all structures are affected the same way, therefore organ sparing during treatment planning for IMRT needs to consider function rather than focusing on select muscles. Dose-response relationships should be investigated with a comprehensive set of swallowing structures to capture the holistic process of swallowing.

Pilot Study of Quantitative Methods for Differentiating Pharyngeal Swallowing Mechanics by Dysphagia Etiology

Quantitative analysis of modified barium swallow (MBS) imaging is useful to determine the impact of various disease states on pharyngeal swallowing mechanics. In this retrospective proof of concept study, kinematic analysis and computational analysis of swallowing mechanics (CASM) were used to demonstrate how these methods differentiate swallowing dysfunction by dysphagia etiology. Ten subjects were randomly selected from four cohorts of dysphagic patients including COPD, head and neck cancer (HNC), motor neuron disease, and stroke. Each subject was age- and gender-matched with healthy, non-dysphagic controls. MBS videos of 5 ml thin and 5 ml thick bolus trials from each subject were used. A MATLAB tracker tool was adapted and updated to collect and compile data for each video (n = 160). For kinematic measurements, a MANOVA was performed with post-hoc analyses to determine group differences. For CASM measurements, a morphometric canonical variate analysis with post hoc analysis was performed to determine group differences. Kinematic analyses indicated statistically significant differences between HNC cohort and controls in distance measurements for hyolaryngeal approximation (p = .001), laryngeal elevation (p = 0.0001), pharyngeal shortening (p = 0.0002), and stage transition duration timing (p = 0.002). Timing differences were noted between the stroke cohort and controls for pharyngeal transit time (p = 0.007). Multivariate morphometric canonical variate analysis showed significant differences between etiology groups (p < 0.0001) with eigenvectors indicating differing patterns of swallowing mechanics. This study demonstrated that swallowing mechanics among cohorts of dysphagic patients can be differentiated using kinematics and CASM, providing different but complementary quantitative methods for investigating the impact of various disease states on swallowing function.

Impact of Thickened Liquids on Laryngeal Movement Velocity in Patients with Dysphagia

Considering that thickened liquids are frequently used for patients with dysphagia, elucidating their impact on laryngeal dynamics is important. Although studies have investigated the impact of thickened liquids on laryngeal movement velocity among healthy young adults, no study has examined the same among patients with dysphagia. We aimed to elucidate the influence of bolus consistency on laryngeal movement velocity and surface electromyographic activity of the suprahyoid muscles in patients with dysphagia. Participants included 18 male, poststroke patients with dysphagia, whereas patients with true bulbar paralysis, head and neck cancer, neuromuscular disease, or recurrent nerve paralysis were excluded. A video fluoroscopic swallowing study (VFSS) was performed while swallowing 3 mL of moderately thick and thin liquids. Quantitative VFSS analysis, including factors such as laryngeal peak velocity, laryngeal mean velocity, laryngeal movement distance, duration of the laryngeal elevation movement, and the temporal location of laryngeal vestibule closure within the laryngeal elevation movement was performed. Muscle activity was evaluated using integrated muscles activity values obtained from electromyography (iEMG) of the suprahyoid muscle during swallowing. VFSS analysis showed that laryngeal peak velocity and laryngeal mean velocity were significantly faster while swallowing moderately thick than while swallowing thin liquids. Laryngeal movement distance was significantly greater while swallowing moderately thick than while swallowing thin liquids. iEMG was significantly higher while swallowing moderately thick liquids than while swallowing thin liquids. Compared to thin liquids, moderately thick induced an increase in laryngeal movement velocity and in suprahyoid muscle activity among patients with dysphagia, a finding consistent with that of a previous study among healthy adults.

The relationship between posterior pharyngeal wall thickness and swallowing function after radiation therapy

Background: Dysphagia is a complication following radiation therapy (RT) for head and neck cancers (HNC). Radiologic findings of posterior pharyngeal wall thickening (PPWT) after RT has not been quantified and correlated to swallowing outcomes.Aims/objective: To evaluate PPWT and its impact on swallowing function following RT.Material and methods: Retrospective analysis of pre- and three-month post-RT PPWT, demographics, oncologic history, and swallowing parameters of patients undergoing RT for HNC. Multivariate analysis of variance was performed to evaluate the effect of PPWT on swallowing outcomes.Results: The mean age of the cohort (n = 207) was 61.8 (± 11.29) years. The mean PPWT increased by 0.28 (± 0.19) cm (p = .00) three-months after RT. A significant difference in PPWT score between tumor subsites, χ²(2) = 45.883, p = .00, with the highest mean rank score of 135.97 for nasopharynx and 103.46 for oropharynx. PPWT was significantly associated with increased pyriform sinus retention, higher Penetration-Aspiration Scale (PAS) scores and post-deglutitive aspiration (p < .05).Conclusions and significance: PPWT increase significantly after RT for HNC. Increased PPWT was associated with mean radiation dose to the nasopharynx and oropharynx and was an independent risk factor for increased pharyngeal residue, higher PAS scores, and timing of aspiration (p < .05).

Swallowing Patterns in the HNC Population: Timing of Penetration-Aspiration Events and Residue

Objective

This study described swallowing patterns in a large head/neck cancer (HNC) cohort.

Study Design

In a retrospective review of data from a randomized controlled trial, we studied timing of penetration events as they related to aspiration and oral/pharyngeal residue.

Setting

Retrospective review of a multicenter randomized controlled trial.

Subjects and Methods

In total, 168 patients who were >3 months postradiation received baseline modified barium swallow evaluations. Retrospective analyses of data from these exams were studied, including Penetration-Aspiration Scale (PAS) scores and timing of these events (before, during, or after the swallow), as well as percentage of oral and pharyngeal residue.

Results

Aspiration occurred more frequently after than before or during the swallow ( P < .05). There were significantly more events of penetration that led to aspiration after the swallow (n = 260) when compared to events before (n = 6) or after (n = 81) the swallow. There was more pharyngeal (16%-25%) than oral residue (5%-20%). Weak correlations were found between thin liquid, nectar-thick liquid, pudding residue, and PAS scores, with varying significance (pharyngeal residue/PAS rs: .26*, .35*, .07*; oral residue/PAS rs: .21*, .16, .3; * P < .05).

Conclusion

The predominant pattern for this sample of postradiation patients with HNC with dysphagia was aspiration that occurred after the swallow, rather than before or during the swallow. The aspiration was directly caused by penetration events that occurred during the swallow, resulting in aspiration as the airway reopened. Patients demonstrated more pharyngeal residue than oral residue, but a weak relationship was found between residue and penetration/aspiration events. These results guide clinicians in targeting appropriate swallowing interventions.

MRI Assessment of Swallow Muscle Activation with the Swallow Exercise Aid and with Conventional Exercises in Healthy Volunteers: An Explorative Biomechanical Study

Swallowing muscle strength exercises are effective in restoring swallowing function. In order to perform the exercises with progressive load, the swallow exercise aid (SEA) was developed. Precise knowledge on which muscles are activated with swallowing exercises, especially with the SEA, is lacking. This knowledge would aid in optimizing the training program to target the relevant swallowing muscles, if necessary. Three healthy volunteers performed the three SEA exercises (chin tuck against resistance, jaw opening against resistance and effortful swallow) and three conventional exercises [conventional effortful swallow (cES), Shaker and Masako] in supine position inside an MRI scanner. Fast muscle functional MRI scans (generating quantitative T2-maps) were made immediately before and after the exercises. Median T2 values at rest and after exercise were compared to identify activated muscles. After the three SEA exercises, the suprahyoid, infrahyoid, sternocleidomastoid, and lateral pterygoid muscles showed significant T2 value increase. After the Shaker, the lateral pterygoid muscles did not show such an increase, but the three other muscle groups did. The cES and Masako caused no significant increase in any of these muscle groups. During conventional (Shaker) exercises, the suprahyoid, infrahyoid, and sternocleidomastoid muscles are activated. During the SEA exercises, the suprahyoid, infrahyoid, sternocleidomastoid, and lateral pterygoid muscles are activated. The findings of this explorative study further support the potential of the SEA to improve swallowing rehabilitation.

Impaired Movement Scaling and Reduced Synchrony with Vestibule Closure Characterize Swallowing in Severe Dysphagia

The contribution of hyoid and laryngeal movement deficits to penetration or aspiration in dysphagia is unclear, partly due to large variations in normal hyolaryngeal kinematics for swallowing. In healthy volunteers, laryngeal and hyoid kinematics relate to the requirements for laryngeal vestibule closure suggesting a central schematic control of movement magnitude and patterning for airway protection. Our first aim was to determine if patients with severe dysphagia showed evidence of an impaired swallowing schema, by examining if their kinematic measures were related to their hyolaryngeal space before swallow onset, and if hyolaryngeal movement synchrony for vestibule closure was disrupted. Our second aim was to determine the kinematic measures that predicted bolus penetration and aspiration in dysphagia. The methods included two-dimensional measures of the hyoid and laryngeal anterior and superior displacement and velocity, and the change in laryngeal vestibule area made from videofluoroscopic swallow recordings of 21 healthy volunteers and 21 patients with dysphagia on tube feeding secondary to the stroke or head and neck cancer. The results demonstrated that the patients did not adapt their hyolaryngeal movements during swallowing to their initial hyolaryngeal space. Further, none of the patients' measures of hyoid or laryngeal peak velocity timing were synchronized with vestibule closure, demonstrating a disorganized movement patterning. Laryngeal elevation peak velocity independently predicted penetration and aspiration. In conclusion, the central schema for swallowing patterning was disturbed, impairing the integration of kinematic actions for airway protection in severe dysphagia, while laryngeal peak elevation velocity predicted penetration and aspiration on patient swallows.

Use of the Penetration-Aspiration Scale in Dysphagia Research: A Systematic Review

The penetration-aspiration scale (PAS) is an 8-point scale used to characterize the depth and response to airway invasion during videofluoroscopy. Though widely used in the field of deglutition, there is a lack of consensus regarding the statistical properties of the scale. In order to better understand the state of the literature and the statistical use of the PAS, a systematic review was undertaken to descriptively examine trends in statistical and reporting practices of the PAS since its inception. Online databases were searched for studies citing the original PAS article, which yielded 754 unique articles. Of these, 183 studies were included in the review. Results showed inconsistencies in the statistical use of the scale; 79 studies treated the PAS as ordinal, 71 as categorical, and 49 as interval. Ten types of categorizations were identified. Reporting of power analyses (9%), as well as inter- (26%) and intra-rater (17%) reliability, was uncommon. Among studies that administered multiple bolus volumes or consistencies, 55% reported PAS analyses at the participant/group level only. This review confirms the existence of discrepancies in the statistical treatment of the PAS. A lack of consensus among researchers limits comparisons between studies. The approach to handling this scale dictates the statistical tests used, potentially affecting results and interpretations. Consistent application of statistically sound approaches to PAS analyses is vital for the future of deglutition research.

Utilization of rehabilitation services in patients with head and neck cancer in the United States: A SEER-Medicare analysis

BACKGROUND

Head and neck cancer (HNC) and its treatment lead to functional impairments. Rehabilitation by speech-language pathology (SLP) and occupational/physical therapy (OT/PT) can decrease morbidity.

METHODS

The Surveillance, Epidemiology and End Results-Medicare data for patients with HNC diagnosed between 2002 and 2011 was utilized to evaluate posttreatment rehabilitation.

RESULTS

In 16 194 patients, the overall utilization rate was 20.7% for SLP and 26.2% for OT/PT services. Treatment modality was significantly associated rehabilitation utilization. Compared to patients treated with primary surgery, those treated with primary radiotherapy had significantly lower odds of OT/PT utilization. Patients treated with surgery plus adjuvant treatment and primary concurrent chemoradiation had higher odds of SLP utilization compared to patients treated with surgery alone.

CONCLUSIONS

Rehabilitation services appeared to be underutilized by patients with HNC in the United States and vary with treatment modality. There is a need to improve integration of rehabilitation services into the HNC care continuum.

SUMMARY

Rehabilitation services are underutilized by patients with HNC during posttreatment surveillance in the United States. Treatment modality significantly impacts rehabilitation utilization patterns.

Association Between Pharyngeal Pooling and Aspiration Using Fiberoptic Endoscopic Evaluation of Swallowing in Head and Neck Cancer Patients with Dysphagia

Postswallow pharyngeal pooling may be a risk factor for tracheal aspiration. However, limited literature shows the potential association between pharyngeal pooling and aspiration in head and neck cancer (HNC) patients. This study investigates the relationship between postswallow pharyngeal pooling and aspiration in HNC patients with oropharyngeal dysphagia. Furthermore, the effects of tumor stage, tumor location, and cancer treatment on aspiration were examined. Ninety dysphagic HNC patients underwent a standardized fiberoptic endoscopic evaluation of swallowing (FEES) using thin and thick liquid boluses. For each swallow, three visuoperceptual ordinal variables were scored: postswallow vallecular pooling, postswallow pyriform sinus pooling, and aspiration. Logistic regression analyses with correction for the location of pooling, tumor stage, tumor location, and cancer treatment were performed to explore the association between pooling and aspiration. No significant association was found between postswallow vallecular pooling and aspiration for thin liquid. However, severe versus mild-to-moderate postswallow vallecular pooling of thick liquid was significantly associated to aspiration. Similar results were seen after correction for the presence of pyriform sinus pooling, tumor stage, tumor location, or type of cancer treatment. This study showed a significant association between severe postswallow pyriform sinus pooling of thick liquid and aspiration, independent of the presence of vallecular pooling, tumor stage, tumor location, or cancer treatment. Concluding, location (valleculae versus pyriform sinuses), liquid bolus consistency (thin versus thick liquid), and amount of postswallow pharyngeal pooling (no pooling, mild/moderate pooling, severe pooling) have an influence on the probability of aspiration in dysphagic HNC patients, and they should be carefully considered during FEES, even in the absence of aspiration during the examination.

Age-related alterations in swallowing biomechanics

BACKGROUND

Aging rodent models allow for the discovery of underlying mechanisms of cranial muscle dysfunction. Methods are needed to allow quantification of complex, multivariate biomechanical movements during swallowing. Videofluoroscopic swallow studies (VSS) are the standard of care in assessment of swallowing disorders in patients and validated quantitative, kinematic, and morphometric analysis methods have been developed. Our purpose was to adapt validated morphometric techniques to the rodent to computationally analyze swallowing dysfunction in the aging rodent.

METHODS

VSS, quantitative analyses (bolus area, bolus velocity, mastication rate) and a rodent specific multivariate, morphometric computational analysis of swallowing biomechanics were performed on 20 swallows from 5 young adult and 5 old Fischer 344/Brown Norway rats. Eight anatomical landmarks were used to track the relative change in position of skeletal levers (cranial base, vertebral column, mandible) and soft tissue landmarks (upper esophageal sphincter, base of tongue).

RESULTS

Bolus area significantly increased and mastication rate significantly decreased with age. Aging accounted for 77.1% of the variance in swallow biomechanics, and 18.7% of the variance was associated with swallow phase (oral vs pharyngeal). Post hoc analyses identified age-related alterations in tongue base retraction, mastication, and head posture during the swallow.

CONCLUSION

Geometric morphometric analysis of rodent swallows suggests that swallow biomechanics are altered with age. When used in combination with biological assays of age-related adaptations in neuromuscular systems, this multivariate analysis may increase our understanding of underlying musculoskeletal dysfunction that contributes to swallowing disorders with aging.

Functional Swallowing Units (FSUs) as organs-at-risk for radiotherapy. PART 1: Physiology and anatomy

BACKGROUND AND PURPOSE

When optimising radiotherapy treatments today, the pharyngeal constrictor muscles and the larynx are usually regarded as the swallowing organs at risk (SWOARs). The purpose of this study was to identify and describe additional, previously undefined groups of muscles (functional units) involved in crucial components of swallowing (hyolaryngeal elevation (HLE), tongue base retraction (TBR) and tongue motion), and to emphasise their relevance in radiation-induced dysphagia.

MATERIAL AND METHODS

Based on available literature on human anatomy and swallowing physiology, the functional units of muscles involved in HLE, TBR and tongue motion have been identified and described.

RESULTS AND CONCLUSION

Functional swallowing units (FSUs) were defined as groups of swallowing muscles sharing their function, that are in close proximity to each other. Seven FSUs involved in HLE, TBR and tongue motion were identified: floor of mouth, thyrohyoid muscles, posterior digastric/stylohyoid muscles complex, longitudinal pharyngeal muscles, hyoglossus/styloglossus muscles complex, genioglossus muscles, intrinsic tongue muscles. The swallowing physiology and anatomy of the FSUs described in this paper will lead to a greater understanding of radiation-induced dysphagia mechanisms and, consequently, to an improvement in the development of swallowing sparing strategies. This article (PART 1) serves as the theoretical foundation for a subsequent article (PART 2), which provides detailed delineation guidelines for FSUs.

Reflections on Clinical and Statistical Use of the Penetration-Aspiration Scale

The 8-point Penetration-Aspiration Scale (PAS) was introduced to the field of dysphagia in 1996 and has become the standard method used by both clinicians and researchers to describe and measure the severity of airway invasion during swallowing. In this article, we review the properties of the scale and explore what has been learned over 20 years of use regarding the construct validity, ordinality, intervality, score distribution, and sensitivity of the PAS to change. We propose that a categorical revision of the PAS into four levels of increasing physiological severity would be appropriate. The article concludes with a discussion of common errors made in the statistical analysis of the PAS, proposing that frequency distributions and ordinal logistic regression approaches are most appropriate given the properties of the scale. A hypothetical dataset is included to illustrate both the problems and strengths of different statistical approaches.

Effects of chin-up posture on the sequence of swallowing events

BACKGROUND

Chin-up posture is frequently used to manage oral dysphagia after head and neck cancer. This prospective study investigates the effects of chin-ups on the sequence of pharyngeal swallowing events.

METHODS

Twelve healthy young adults performed 45 consecutive swallows of 5 mL water across 3 phases on videofluoroscopy: 5 swallows in the neutral head position; 30 swallows during chin-up posture; and 10 swallows in the neutral head position. Swallowing kinematic and bolus flow measures for 9 swallowing events were recorded. Linear trends were analyzed across 30 chin-up swallows; pairwise comparison was used to compare the 3 phases.

RESULTS

Time to hyoid peak and laryngeal vestibule closure changed abruptly during chin-up swallowing compared to the initial neutral position. No measure changed across 30 chin-up swallows. Time of hyoid burst decreased upon returning to the neutral position.

CONCLUSION

Our findings indicate that chin-up posture challenges the pharyngeal sequence of events for both swallowing kinematics and bolus flow. © 2017 Wiley Periodicals, Inc. Head Neck 39: 947-959, 2017.