The effect of Pharyngeal Electrical Stimulation (PES) on peripheral biomechanical aspects of deglutition.

Swallowing problems after stroke represent a major clinical problem, with over 40,000 patients annually suffering from dysphagia with consequent aspiration/pneumonia. This leads to longer hospital stays, increased demands on feeding resources, higher admission rates to nursing homes and worse survival, costing society an estimated £400 million a year. Traditionally, swallow therapists have used dietary modifications and bedside “treatment” strategies to rehabilitate swallowing despite little evidence of benefit. With the incidence of stroke and neurological diseases projected to increase over the next 20 years, the problem of dysphagia is likely to grow, and more effective approaches to managing neurogenic dysphagia become critical. Against this background, previous work from the UK has probed the physiological basis of successful recovery from dysphagia in acute stroke patients, leading to development of pharyngeal electrical stimulation therapy that is now undergoing clinical trials in the acute dysphagia setting. In the last decade, the role of cortical plasticity in the human swallowing motor system became clear and novel stimulation methods were explored to accelerate plasticity and induce swallowing recovery in acute dysphagic stroke. Recent pilot studies have shown that these neurostimulation approaches also hold promise in more chronic forms of dysphagia, both on the pharyngeal and esophageal motor dysfunction function. Although the central effect of neurostimulation has been clearly documented, the peripheral effect of electrical stimulation on the pharyngeal and esophageal swallow function remains unexplored. At this point, an objective, numerical evaluation of the effect of pharyngeal stimulation of deglutitive structures, muscles and their biomechanical function is lacking, but needed. The primary objective of the current project is to evaluate the peripheral effect of pharyngeal neurostimulation intervention on the biomechanics of swallowing using the technique of high resolution manometry impedance, given the extensive knowledge and experience available at KULeuven – UZ Leuven of this state-of-the-art method. The secondary objective of the study is to test the capability of pharyngeal neuro-stimulation 1. to alter the biomechanics of swallowing and 2. to reduce aspiration in acute neurogenic dysphagia patients. We propose a randomised clinical trial of the pharyngeal stimulation intervention versus placebo in healthy controls and in patients with acute neurogenic dysphagia, aiming to assess swallow motor function and ultimately reduce aspiration and promoting safe swallowing in patients.