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

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. Fifteen adults (8 males; 45-86 years) with mixed etiology dysphagia were consecutively recruited over a three-month period. PHRM equipment with a 4.2 mm pressure catheter was used. The protocol included duplicate 10 ml neutral, sour, cold, and carbonated liquid swallows in randomized order. Semi-automated analysis was completed using an online portal ( www.swallowgateway.com ). 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 5.17 mmHg) (p = 0.032). No significant changes were observed to UES basal pressure or UES peak pressure with sensory stimulation. 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.