Older adults may evidence changes in swallowing physiology. Our goals were to identify dysphagia risk in community-dwelling older adults with no history of dysphagia, and to compare swallowing physiology and safety between older and younger adults. Thirty-two older adults with no history of dysphagia were prospectively recruited and completed the Dysphagia Handicap Index (DHI), two trials of a 3 oz. swallow screen, and videofluoroscopy (VFSS). Self-ratings of swallowing function were compared to published norms by paired t tests, and multivariate logistic regression models were generated to determine whether these ratings and VFSS analysis of swallowing function were associated with failure of one or both swallow screen trials. Archived VFSS of 33 younger adults were compared to older adults with Wilcoxon rank-sum tests. The DHI scores of older adults were higher than published non-dysphagic adults but lower than dysphagic adults. Older participants with greater Oral Residue scores were more likely to fail both swallow screen trials. Older adults received higher median MBSImP™© scores for select pharyngeal components than younger adults. The two age groups did not differ on Penetration-Aspiration Scale scores, and no aspiration was observed. Measures of swallowing in older individuals may reflect age-related sensory and motor changes in the context of functional swallowing and adequate airway protection.

Sour stimuli have been shown to upregulate swallowing in patients and in healthy volunteers. However, such changes may be dependent on taste-induced increases in salivary flow. Other mechanisms include genetic taster status (Bartoshuk LM, Duffy VB, Green BG, Hoffman HJ, Ko CW, Lucchina LA, Weiffenbach JM. Physiol Behav 82: 109-114, 2004) and differences between sour and other tastes. We investigated the effects of taste on swallowing frequency and cortical activation in the swallowing network and whether taster status affected responses. Three-milliliter boluses of sour, sour with slow infusion, sweet, water, and water with infusion were compared on swallowing frequency and hemodynamic responses. The sour conditions increased swallowing frequency, whereas sweet and water did not. Changes in cortical oxygenated hemoglobin (hemodynamic responses) measured by functional near-infrared spectroscopy were averaged over 30 trials for each condition per participant in the right and left motor cortex, S1 and supplementary motor area for 30 s following bolus onset. Motion artifact in the hemodynamic response occurred 0-2 s after bolus onset, when the majority of swallows occurred. The peak hemodynamic response 2-7 s after bolus onset did not differ by taste, hemisphere, or cortical location. The mean hemodynamic response 17-22 s after bolus onset was highest in the motor regions of both hemispheres, and greater in the sour and infusion condition than in the water condition. Genetic taster status did not alter changes in swallowing frequency or hemodynamic response. As sour taste significantly increased swallowing and cortical activation equally with and without slow infusion, increases in the cortical swallowing were due to sour taste.

Objectives Dysphagia in patients with myositis is associated with an increased risk of aspiration pneumonia. However, the pathophysiology of dysphagia is poorly understood. The aim of this study was to understand how myositis affects swallowing physiology on videofluoroscopic swallow study. Design This is a retrospective review of video fluoroscopic swallowing studies on 23 myositis patients with dysphagia from 2011 to 2016. Swallow studies were analyzed by timing of swallowing events and duration of swallowing events, diameter of upper esophageal sphincter opening, Modified Barium Swallow Impairment Profile, and Penetration-Aspiration Scale. The outcome measures for patients were compared with an archived videofluoroscopic swallow study from healthy, age-matched participants by Wilcoxon rank-sum tests. Results Patients with myositis had a shorter duration of upper esophageal sphincter opening (P < 0.0001) and laryngeal vestibule closure (P < 0.0001) than healthy subjects. The diameter of upper esophageal sphincter opening did not differ between groups. Patients with myositis presented with higher scores on the MBSIMP than healthy subjects, indicating great impairment particularly during the pharyngeal phase of swallowing, and a higher frequency of penetration and aspiration. Conclusions Dysphagia in patients with myositis may be attributed to reduced endurance of swallowing musculature rather than mechanical obstruction of the upper esophageal sphincter.