Yoko Inamoto

Background: Pill‐swallowing difficulty is common yet under‐recognised, and patients rarely seek or receive support from healthcare professionals. Lubricating jelly pastes are widely available in Japan, yet evidence for their effectiveness in pill administration remains limited. The PILL‐5 enables validated, self‐reported screening of clinically relevant pill‐swallowing difficulty. Aim: This study aimed to explore whether a lubricating jelly paste reduced self‐reported pill‐swallowing difficulties using the Japanese version of the PILL‐5 questionnaire. Method: In a pilot randomised, parallel‐group trial, 24 participants with PILL‐5 scores ≥2 were stratified and randomised 1:1 to one‐week pill intake using a lubricating jelly paste (IDDSI Level 4) (intervention group) or pill intake as usual (control group). The PILL‐5 was administered at baseline, Day 1, and Day 7. The primary outcome was change in total PILL‐5; between‐group differences were tested with the exact Mann–Whitney U test. Ethical approval was granted by the Ethics Review Committee of Fujita Health University (Reference no: HM20‐076; HM20‐619) and the study conforms with the Declaration of Helsinki. Informed consent was obtained from all participants via the distribution of project information and completion of written consent forms. The study was registered in the UMIN Clinical Trials Registry (UMIN‐CTR) (Registration ID: UMIN000057324). Results: The median PILL‐5 scores at baseline were 4.5 and 5.5 for the intervention and control groups, respectively (p = 0.525). At Day 1, median scores were 3.0 and 4.5 in the intervention group and control group, respectively and on Day 7, median scores were 3.0 and 4.0 in the intervention and control groups, respectively. From baseline to Day 1, the between‐group median difference in change (intervention minus control) was 2 (95% confidence interval [CI] 0–2, p = 0.037), indicating a greater reduction in the intervention group. On Day 7, the between‐group difference was 1 (95% CI 0–2, p = 0.119) and not significant. Conclusion: Lubricating jelly paste use was associated with an early, self‐reported reduction in PILL‐5 scores at Day 1, with a significant between‐group difference. By Day 7, the between‐group difference was not significant, likely due to floor effects from low baseline severity. Future studies with stricter inclusion criteria and larger sample sizes are warranted to further clarify the potential benefits.

Previous research in healthy individuals has demonstrated that fast bolus progression of thin liquid results in earlier true vocal fold (TVF) closure compared to thick liquid. This study investigated whether this timing adjustment occurred in individuals with stroke and whether dysphagia severity affected this adjustment. This retrospective observational study included 54 participants with stroke (37 males, 17 females, mean [standard deviation] age: 63.7 [13.8] years) who underwent CT swallow studies with thick and thin liquids (10 ml each). The onset of TVF closure, laryngeal vestibule (LV) closure, maximum epiglottic inversion, and bolus head progression were compared between 2 consistencies. Subgroup analysis was based on the Dysphagia Severity Scale (DSS). The results showed that thin liquid reached the vallecula, hypopharynx, and esophagus significantly earlier than thick liquid. Onset of TVF closure was significantly earlier with thin liquid (median: 0.2 s [range: -1.5 to 0.5] vs. 0.3 s [range: -1.7 to 0.6], p = 0.020) with no significant differences in onset of LV closure or maximum epiglottic inversion. Subgroup analysis revealed significantly earlier TVF and LV closure with thin liquid only in the mild (DSS 5 and 6) group. Patients with moderate (DSS 4) and moderately severe (DSS 3) dysphagia did not show these differences. In conclusion, TVF and LV closure occurred earlier in response to faster bolus transport in stroke patients. However, this finding varied by dysphagia severity and was absent in the groups with more severe dysphagia. These data support the idea that TVF and LV adjustments are important factors in airway protection.

Objective: Oral frailty, the age‐related decline in oral and pharyngeal function, is associated with physical frailty, sarcopenia, and cognitive decline. The Oral Frailty Index‐8 (OFI‐8) is a patient‐reported outcome measure developed in Japan to assess oral frailty risk. This study aimed to culturally and linguistically adapt the OFI‐8 for English‐speaking older adults in the United States. Study Design: Cross‐cultural and cross‐linguistic adaptation of the OFI‐8 by an expert committee, followed by administration of the adapted OFI‐8 and structured cognitive interviews with 22 English‐speaking adults aged 65 years and older. Setting: Outpatient tertiary academic voice and swallowing center in New York City. Methods: Following the Professional Society for Health Economics and Outcomes Research (ISPOR) guidelines, the OFI‐8 underwent forward translation, back translation, expert committee review, and reconciliation. Cognitive interviews were then conducted with 22 participants aged 65 years and older. A think‐aloud and verbal‐probing approach was used to evaluate comprehension, clarity, and cultural appropriateness. Interviews were transcribed and analyzed using thematic analysis. Results: Several cultural adaptations were made, including replacing Japanese food examples with US‐familiar foods of similar texture. Three questionnaire items and the instructions were refined following participant feedback to improve syntactic flow, clarity, and understanding. The final US‐English version maintained conceptual equivalence of the original OFI‐8 while adapting language and examples for US cultural relevance. Conclusion: A culturally adapted US‐English version of the OFI‐8 was developed through structured translation, expert review, and cognitive interviews. Further validation studies are necessary to establish its clinimetric properties and support clinical application for early detection of oral frailty in US older adults.

This study aimed to establish reference values for quantitative measurements of pharyngeal volume and residue during swallowing in healthy individuals and to examine how these measurements are influenced by age, sex, height, and bolus properties. We performed a retrospective analysis of 288 swallows from 135 healthy Japanese adults (median age, 43 years; height, 163 cm) who underwent Swallowing CT. Test boluses included thin or extremely thick liquids in either 3 mL, 10 mL, or 20 mL amounts. Pharyngeal cavity volume at bolus hold (PVHOLD), unobliterated air and bolus volume at maximum pharyngeal constriction (PVMAX), and pharyngeal volume constriction ratio (PVCR), and post-swallow pharyngeal residue were measured on dynamic 3D-CT images using a semi-automated software. We determined the 2.5th, 50th, 97.5th percentile values to obtain normative reference values for each parameter and made generalized linear regression models to determine how these volume measurements are associated with demographic factors and bolus properties. Normative values (median [97.5th percentile]) across all swallows were PVHOLD 20.9 cm³ [38.6 cm³], PVMAX 0.3 cm³ [2.1 cm³], PVCR 98.8% [2.5th percentile 89.1%], and residue 0 cm³ [0.4 cm³]. Males exhibited larger values than females. PVHOLD significantly increased with height (β = 0.465, p < 0.001) and age (β = 0.068, p = 0.001), while PVMAX and PVCR increased with larger bolus volumes (β = 0.293, p = 0.005) and in thicker consistencies (β = 0.376, p = 0.017). Pharyngeal residue was present in 98/288 (34.0%) of swallows and was significantly associated with increasing bolus volume (adjusted odds ratio [aOR] = 1.865 [95% confidence interval: 1.275–2.727]), age (aOR = 1.025 [1.010–1.040]), thicker bolus (aOR = 1.806 [1.275–2.727]). Each 1 cm² increase in PVMAX was associated with nearly double the odds of residue (aOR = 1.86 [1.202–2.862]). Similarly, each 1% decrease in PVCR corresponded to a 10.6% increase in the odds of residue (aOR = 1.106 [1.015–1.295]). These normative data provide a bases for comparing individuals with or without pharyngeal impairments.

Purpose of Review: Swallowing computed tomography (CT) allows dynamic three-dimensional visualization of swallowing. This review article summarizes the advantages and disadvantages of performing swallowing CT. Recent Findings: Visualization of swallowing-related structures three-dimensionally supports the use of swallowing CT in clinical, research, and educational settings. Several morphological and kinematic analyses can be performed to study swallowing physiology and pathophysiology. However, radiation dose, reclining posture during scanning, and lower time resolution compared to videofluoroscopy are disadvantages of this technology. Technological advances may mitigate these disadvantages in the future. Summary: Swallowing CT can be used in clinical, educational, and research applications while recognizing that limitations exist to the use of this modality.

Background: Upper oesophageal sphincter (UES) serves as an important anatomical and functional landmark during swallowing. However, the precise UES location before and during swallowing has not been well established.Objective: This study aimed to determine upper oesophageal sphincter (UES) location and displacement during swallowing accounting for sex, age, and height in healthy adults using 320‐row area detector computed tomography (320‐ADCT).Methods: Ninety‐four healthy adults (43 males; 22–90 years) underwent 320‐ADCT scanning while swallowing one trial of 10 mL honey thick barium. UES location at bolus hold and at maximum displacement and vertical displacement during swallowing were identified using the coordinates and the section classification of vertebrae (VERT scale). The differences and correlations of UES location and distance in terms of sex, age, and height were analysed using Mann–Whitney U test and Spearman's correlation coefficient.Results: UES locations at bolus hold and at maximum displacement were significantly lower and UES vertical displacement was significantly larger in males than in females (p < .001). UES location at bolus hold became lower with increasing age (r = −.312, p = .002), but the negative correlation was low at maximum displacement (r = −.230, p = .026), resulting in larger vertical distance with ageing. UES locations showed high negative correlation at bolus hold with height (r = −.715, p < .001), and showed moderate negative correlation at maximum displacement with height (r = −.555, p < .001), although this effect was unclear when analysed by sex.Conclusion: Males showed lower UES location and larger displacement than females. The impact of age was evident with lower location before swallowing and larger displacement during swallowing. Differences observed by sex were not completely explained by using the VERT scale to adjust for height.

This study evaluated the validity of pharyngeal 2D area measurements acquired from the lateral view for predicting the actual 3D volume in healthy adults during swallowing. Seventy-five healthy adults (39 females, 36 males; mean age 51.3 years) were examined using 320-row area detector computed tomography (320-ADCT). All participants swallowed a 10 mL honey-thick barium bolus upon command while seated in a 45° semi-reclining position. Multi-planar reconstruction images and dynamic 3D-CT images were obtained using Aquilion ONE software. Pharyngeal 2D area and 3D volume measurements were taken before swallowing and at the frame depicting maximum pharyngeal constriction. Pharyngeal volume before swallowing (PVhold) was accurately predicted by 2D area (R² = 0.816). Adding height and sex to the model increased R² to 0.836. Regarding pharyngeal volume during maximum constriction (PVmax), 2D area also exhibited acceptable predictive power (R² = 0.777). However, analysis of statistical residuals and outliers revealed a greater tendency for prediction errors when there is less complete constriction of the pharynx as well as asymmetry in bolus flow or movement. Findings highlight the importance of routinely incorporating anterior–posterior views during VFSS exams. Future work is needed to determine clinical utility of pharyngeal volume measurements derived from 320-ADCT.

Objectives: Hyolaryngeal movement during swallowing is essential to airway protection and bolus clearance. Although palpation is widely used to evaluate hyolaryngeal motion, insufficient accuracy has been reported. The Bando Stretchable Strain Sensor for Swallowing (B4S™) was developed to capture hyolaryngeal elevation and display it as waveforms. This study compared laryngeal movement time detected by the B4S™ with laryngeal movement time measured by videofluoroscopy (VF).Methods: Participants were 20 patients without swallowing difficulty (10 men, 10 women; age 30.6 ± 7.1 years). The B4S™ was attached to the anterior neck and two saliva swallows were measured on VF images to determine the relative and absolute reliability of laryngeal elevation time measured on VF and that measured by the B4S™.Results: The intra-class correlation coefficient of the VF and B4S™ times was very high [ICC (1.1) = 0.980]. A Bland–Altman plot showed a strong positive correlation with a 95% confidence interval of 0.00–3.01 for the mean VF time and mean B4S™ time, with a fixed error detected in the positive direction but with no proportional error detected. Thus, the VF and B4S™ time measurements showed high consistency.Conclusion: The strong relative and absolute reliability suggest that the B4S™ can accurately detect the duration of superior-inferior laryngeal motion during swallowing. Further study is needed to develop a method for measuring the distance of laryngeal elevation. It is also necessary to investigate the usefulness of this device for evaluation and treatment in clinical settings.

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