ABSTRACT
OBJECTIVE: The pharyngeal swallow typically begins within 400 ms following the arrival of a liquid bolus in the pharynx. By contrast, processed food particles aggregate in the valleculae prior to swallow initiation. With solid foods, swallow reaction time (SRT), the interval between bolus passing the ramus of mandible and hyoid burst onset (HYB) can be subdivided into components of vallecular aggregation time (VAT) and the subsequent end of aggregation to hyoid burst interval (EOA-to-HYB). However, expected durations of these timing measures remain unclear. We aimed to study bolus aggregation in healthy swallowing for International Dysphagia Diet Standardisation Initiative Food Levels 5 (minced and moist [MM5]), 6 (soft and bite-sized [SB6]), and 7 (regular [RG7]). Understanding typical patterns and durations of vallecular aggregation with solids in healthy swallowing will inform the identification of impaired swallow timing in patient populations. DESIGN: Twenty healthy adults (10 males, Mage = 28 years, range: 23-55 years) swallowed two boluses each of MM5, SB6, and RG7 foods in videofluoroscopy. Blinded duplicate ratings determined bolus location at swallow onset, SRT, VAT, and EOA-to-HYB. Texture-based differences were measured using Friedman's tests. Bolus location was at/above the valleculae at swallow onset for 85% of boluses, with no differences by texture. SRT, VAT, and EOA-to-HYB did not vary by texture, with overall median values (interquartile range) of 99 ms (-66 to 743 ms) for SRT, 347 ms (66 to 891 ms) for VAT, and -132 ms (-231 to -83 ms) for EOA-to-HYB. CONCLUSIONS: These data corroborate prior evidence that it is not unusual for food particles to aggregate in the valleculae prior to swallow initiation in healthy swallowing. However, durations of vallecular aggregation are typically < 1 s in healthy adults.
ABSTRACT
PURPOSE: Videofluoroscopic (VFSS) measurements of pharyngeal swallow mechanics can differentiate age- and disease-related changes in swallowing. Pharyngeal area at rest (PhAR) may differ in people with dysphagia, although its impact is not clear. Before the role of PhAR in dysphagia can be explored, it is important to establish whether PhAR remains stable across repeated measures in healthy adults, and varies as a function of sex or age. We hypothesized that healthy adults would show stable PhAR across repeated measures, but that larger PhAR would be seen in men versus women and in older versus younger adults. METHOD: We collected VFSS data from 87 healthy adults (44 men, M age = 46 years, range: 21-82). Trained raters identified the swallow rest frame after the initial swallow of each bolus and measured unobliterated pharyngeal area on these frames, in %(C2-4)2 units. Repeated-measures analyses of variance with a factor of sex, a covariate of age, and a repeated factor of task repetition were performed across the first 12 available measures per participant (N = 1,044 swallows). RESULTS: There were no significant variations in PhAR across repeated measures. A significant Sex × Age interaction was seen (p = .04): Males had significantly larger PhAR than females (p = .001), but females showed larger PhAR with advancing age (R = .47). CONCLUSIONS: These data confirm stability in PhAR across repeated measurements in healthy individuals. However, significant sex and age differences should be taken into consideration in future studies exploring the role of PhAR in people with dysphagia. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.22043543.
