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Kinematic Analysis of Dysphagia: Significant Parameters of Aspiration Related to Bolus Viscosity

The purpose of this study was to investigate the mechanisms of aspiration with respect to the viscosity of ingested material in patients with dysphagia. Seventy patients with dysphagia underwent videofluoroscopic swallow studies (VFSS) between May 1, 2009 and September 30, 2009. Based on the findings of the VFSS, patients were divided into three groups: a thick-fluid aspiration group, a thin-fluid aspiration group, and a no-aspiration group. Kinematic analyses were performed during thick-fluid swallowing. Among our 70 patients, 23 had thick-fluid aspiration, 20 had thin-fluid aspiration, and 27 had no aspiration. A shortened duration of upper esophageal sphincter (UES) opening, a shorter interval between UES opening and peak pharyngeal constriction, and a diminished extent of laryngeal elevation were all significant risk factors for thick-fluid aspiration. A prolonged latency of the swallowing reflex, pharyngeal transit time, and the interval between bolus arrival at the vallecula and laryngeal elevation were all significant risk factors for thin-fluid aspiration. Our kinematic analysis of dysphagia employing the VFSS indicated that the mechanisms relevant to aspiration differed with respect to food viscosity.

from Dysphagia

Effects of Age, Gender, Bolus Condition, Viscosity, and Volume on Pharyngeal and Upper Esophageal Sphincter Pressure and Temporal Measurements During Swallowing

Purpose: The purpose of this study was to determine the effects of trial (i.e., trial 1 vs. 2), viscosity (i.e., saliva, thin, nectar-, honey-, and pudding-thick water), volume (i.e., 5 vs. 10 ml), age (i.e., young vs. older adults), and gender on pharyngeal (i.e., upper and lower) and upper esophageal sphincter (UES) pressures, durations, and onsets (i.e., onset of upper pharyngeal pressures relative to onsets of UES relaxations and onset of lower relative to upper pharyngeal pressures).

Method: Twenty-three young (M = 30.0 years) and 21 older healthy adults (M = 75.0 years) participated. Measurements were acquired with a 2.1 mm catheter during simultaneous manometric and endoscopic swallowing assessment. Participants contributed 18 swallows affording a study total of 792 swallows for analyses.

Results: There was no significant effect of trial on any measurement of pressure, duration, and onset (p = 0.63, 0.39, and 0.71, respectively). It was found that viscosity, volume, age, and gender affected pressure, duration, and onset measurements (e.g., onset of upper pharyngeal pressures relative to onsets of UES relaxations) but in varying degrees relative to the location in the pharynx or UES and the type of measurement (e.g., pressure, onset).

Conclusions: Manometric measurements vary with respect to age, gender, and bolus variables and interactions of each. Consideration of these variables is paramount in understanding normal and pathological swallowing if manometry is to develop as a quantitative adjunct to videofluoroscopic and endoscopic swallowing tools.

from the Journal of Speech, Language, and Hearing Research