Initiation of Pharyngeal Response during Discrete Swallowing and Chew-swallowing in Healthy Subjects

• Published in: Progress in Rehabilitation Medicine Vol. 1; p. 20160002
• Main Authors: Kagaya, Hitoshi, Saitoh, Eiichi, Inamoto, Yoko, Yokoyama, Michio, Shibata, Seiko, Aoyagi, Yoichiro, Kanamori, Daisuke
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Association of Rehabilitation Medicine 2016; JARM
• Subjects: chew-swallowing; discrete swallowing; dysphagia; Original; stage transition duration; discrete swallowing; dysphagia; stage transition duration; chew-swallowing
• ISSN: 2432-1354; 2432-1354
• DOI: 10.2490/prm.20160002

Objective: The aim of this study was to measure the initiation of pharyngealswallowing during discrete swallowing and during chew-swallowing in younger and olderhealthy subjects and to determine the normal range of the stage transition duration (STD)for different food boluses. The correlations between STDs were investigated.Methods: Twenty-eight younger subjects (< 60 years old) and 25 oldersubjects (≥ 60 years old) were enrolled. While in the sitting position, the subjectsswallowed 10 ml of thin liquid barium (LQ), 8 g of corned beef hash with barium (CB), 8 gof cookie with barium (CK), and a two-phase mixture of 4 g of corned beef hash with bariumand 5 ml of thin liquid barium (MX). A videofluoroscopic examination of swallowing wasperformed at 30 frames/s in the lateral projection. The delay in pharyngeal swallowing(i.e., STD) was measured. The normal range (mean ± 2SD) of STDs for each bolus type wasdetermined, and correlations were calculated to examine the relationship among STDs.Results: The median STDs for LQ, CB, CK, and MX in all subjects were 0.0,1.2, 2.4, and 1.9 s, respectively. The STDs were prolonged for CB, CK, and MX comparedwith LQ. Additionally, the median STD was longer for LQ, CB, and CK in older than inyounger subjects. No significant correlations were found between STDs except for thosebetween CB and CK. Conclusions: A delayed pharyngeal response is commonlyobserved during chew-swallowing. Liquids, solids, and two-phase mixtures exhibitindependent timings of pharyngeal swallow initiation.