Impact of Sensory Stimulation on Pharyngo-esophageal Swallowing Biomechanics in Adults with Dysphagia: A High-Resolution Manometry Study

Abstract

Evidence supporting sensory stimulation of swallowing is based mostly on videofluoroscopy and provides little insight into changes to swallowing physiology. In this study, the impact of sensory stimulation on pharyngo-esophageal swallowing biomechanics was investigated in adults with dysphagia using pharyngeal high resolution manometry. Method(s): Fifteen adults (8 males; 45-86 years) with mixed etiology dysphagia were consecutively recruited over a three-month period. PHRM equipment with a 4.2mm pressure catheter was used. The protocol included duplicate 10ml neutral, sour, cold and carbonated liquid swallows in randomized order. Semi-automated analysis was completed using an online portal (www.swallowgateway.com). Result(s): Data from 98/120 swallows were analyzed. During the pharyngeal phase, mean pharyngeal contractile integral (PhCI) increased significantly with cold (p=0.03), sour (p=0.00) and carbonation (p=0.02). Mean velopharyngeal contractile integral (VCI) (p=0.01) and mesopharyngeal contractile integral (MCI) (p=0.04) both increased significantly with carbonation. Mean hypopharyngeal contractile integral (HPCI) was not significantly altered by sensory stimulation. Regarding UES opening, UES relaxation time (UESRT) increased significantly with cold (p=0.032), carbonation (p=0.032), and sour (p=0.027). Extent of UES opening as measured by IRP reduced significantly with cold stimulation (9.34 to 5.17mmHg) (p=0.032). No significant changes were observed to UES basal pressure or UES peak pressure with sensory stimulation. Conclusions: Sensory stimulation induced biomechanical changes to pharyngeal contraction vigor, UES relaxation time and extent of UES opening during swallowing in adults with dysphagia. This study contributes evidence to support sensory stimulation as a dysphagia intervention. Further combined pressure impedance studies in homogeneous clinical populations are ongoing.

Effect of Tongue-Hold Swallow on Pharyngeal Contractile Properties in Healthy Individuals

“…The nadir UES pressure, i.e., the lowest UES pressure during relaxation, was also measured. Velopharyngeal, mesopharyngeal, hypopharyngeal, and whole pharyngeal contractile integrals and the UES integrated relaxation pressure were analyzed using a semiautomated analysis portal (Swallow Gateway™) [25][26][27]. These pharyngoesophageal integral metrics are in line with the International High-Resolution Pharyngeal Manometry Working Group recommendations [11]; the metrics used in this study are defined in Table 1.…”

“…This portal has excellent interand intra-rater reliability [28,29]. Once the data were uploaded onto the web-based application (www.http//swall owgat eway.com), labeled swallows were identified and six landmarks (including the position of the velopharynx upper margin, hypopharynx upper margin, UES apogee, and UES distal margin, as well as the onset and offset of UES relaxation) were created, which led to the generation of outcomes [26,30]. Specific numbers were assigned for all swallowing events; therefore, the researchers who analyzed the data were blinded with regard to the swallow type (normal, weak THS, and strong THS).…”

Influence of Acid Swallows on the Dynamics of the Upper Esophageal Sphincter

“…As many influencing factors have already been investigated, the mechanism of the UES when exposed to acid during food intake is still uncertain. Some authors have observed an increase in sphincter pressure due to acid exposure of the esophagus [ 9 – 14 ], whereas others did not find any changes in UES pressure when exposed experimentally or spontaneously [ 5 , 15 , 16 ]. Most of these studies have investigated spontaneous reflux events or experimental infusion with hydrochloric acid (HCl) into the esophagus in order to mimic reflux events.…”

“…Most of these studies have investigated spontaneous reflux events or experimental infusion with hydrochloric acid (HCl) into the esophagus in order to mimic reflux events. One study has investigated sensory stimulation in terms of swallowed boli, but did not report of significant pressure changes in the UES in relation with a slightly sour bolus [ 14 ]. Following reports on missing UES reactions in patients with reflux [ 17 ], it has even been proposed that the UES may not take part in preventing esophagopharyngeal reflux at all [ 18 ].…”

Capsaicin combined with ice stimulation improves swallowing function in patients with dysphagia after stroke: A randomised controlled trial

“…Furthermore, and it also may increase the sensitivity of swallowing reflex areas, promote the introduction of sensory impulses before swallowing and produce swallowing reflex to improve swallowing function 36 . However, many scholars 37,38 have pointed out that the effects of ice stimulation for dysphagia are very limited, and the patients’ adherence is not good, more effective interventions are needed.…”