Reproducibility of swallowing over time in healthy elderly adults

Electrophysiological Investigations of Shape and Reproducibility of Oropharyngeal Swallowing: Interaction with Bolus Volume and Age

Electrophysiological assessment provides valuable information on physiological and pathophysiological characteristics of human swallowing. Here, new electrophysiological measures for the evaluation of oropharyngeal swallowing were assessed: (1) the activation pattern of the submental/suprahyoid EMG activity (SHEMG); (2) the reproducibility of the oral and pharyngeal phases of swallowing, by calculating the similarity index (SI) of the SHEMG (SI-SHEMG) and of the laryngeal-pharyngeal mechanogram (SI-LPM) during repeated swallows; and (3) kinesiological measures related to the LPM. An electrophysiological-mechanical method for measuring the activation pattern of the SHEMG, the SI-SHEMG, and the SI-LPM, and maximal LPM velocity and acceleration during swallowing was applied in 65 healthy subjects divided into three age groups (18-39, 40-59, 60 years or over). All the measures were assessed during three trials of eight consecutive swallows of different liquid bolus volumes (3, 12, and 20 ml). A high overall reproducibility of oropharyngeal swallowing in healthy humans was recorded. However, while values of SI-SHEMG were similar in all the age groups, the SI-LPM was found to fall significantly in the older age group. Both the SI-SHEMG and the SI-LPM were found to fall with increasing bolus volumes. The activation pattern of the SHEMG and the LPM kinesiological measures were differently modified by bolus volume and age in the older subjects with respect to the others. We describe a new approach to the electrophysiological study of swallowing based on computed semi-automatic analyses. Our findings provide insight into some previously uninvestigated aspects of oropharyngeal swallowing physiology, considered in relation to bolus volume and age. The new electrophysiological measures here described could prove useful in the clinical setting, as it is likely that they could be differently affected in patients with different kinds of dysphagia.

Effects of carbonated liquids on oropharyngeal swallowing measures in people with neurogenic dysphagia

Aspiration is common in adults with neurogenic dysphagia and pharyngeal delay. This can lead to dehydration, malnutrition, and aspiration pneumonia. Diet modifications aimed at reducing thin liquid aspiration are partially successful or unpalatable or both. Carbonated liquids show some potential in influencing swallowing behavior. However, there is a paucity of evidence to support this intervention. This study compares the effects of carbonated thin liquids (CTL) with that of noncarbonated thin liquids (NCTL) on oropharyngeal swallowing in adults with neurogenic dysphagia and examines the palatability of the CTL stimulus. Seventeen people with pharyngeal delay attended for videofluoroscopy (VFSS). Outcome measures were oral transit time (OTT), pharyngeal transit time (PTT), stage transition duration (STD), initiation of the pharyngeal swallow (IPS), penetration-aspiration scale (PENASP), and pharyngeal retention (PR). A modification of Quartermaster Hedonic Scale (AQHS) was employed to assess palatability of the CTL. CTL vs. NCTL significantly decreased penetration and aspiration on 5-ml (P = 0.028) and 10-ml (P = 0.037) swallows. CTL had no significant effect on OTT, PTT, IPS, and PR for any volume of bolus. Only one participant disliked the CTL stimulus. These findings support the hypothesis that oropharyngeal swallowing can be modulated in response to sensory stimuli. Implications for research and clinical practice are discussed.