Efficacy of EMG/bioimpedance-triggered functional electrical stimulation on swallowing performance

Abstract

In order to support swallowing, the efficacy of functional electrical stimulation for different stimulation settings of the submental musculature has been investigated. The stimulation was administrated at rest and synchronously to voluntary initiated swallows. The onset of a swallow was detected in real-time by a combined electromyography/ bioimpedance measurement at the neck in order to trigger the stimulation. The amplitude and speed of larynx elevation caused by the FES has been assessed by the observed change in bioimpedance whereas a reduction of bioimpedance corresponds to an increase in larynx elevation. Study results from 40 healthy subjects revealed that 73% of the subjects achieved a larger and faster larynx elevation during swallowing with triggered FES and therefor a better protection of their airways. However, we also observed a decrease in larynx elevation compared to normal swallowing in 11 out of the 40 subjects what might not benefit from such a treatment. The largest improvement of larynx elevation and speed during swallowing could be achieved with three stimulation channels formed by four electrodes in the submental region.

Effects of Submental Surface Electrical Stimulation on Swallowing Kinematics in Healthy Adults: An Error-Based Learning Paradigm

“…This includes no pressure changes in the pharynx and upper esophageal sphincter (UES), minimal movement of the hyoid or larynx at rest, and no significant change in labial or lingual force generation (Heck, Doeltgen, & Huckabee, 2012;Humbert, Poletto, Saxon, Kearney, & Ludlow, 2008;Ludlow et al, 2007;Safi, Wright-Harp, Lucker, & Payne, 2017;Suiter, Leder, & Ruark, 2006). One study reported faster laryngeal movements, but no laryngeal imaging was used (electromyography only; Schultheiss, Schauer, Nahrstaedt, Seidl, & Bieler, 2016). Studies of longer term effects in patients with dysphagia report altered hyoid or laryngeal movement but were uncontrolled studies, so it is unclear whether effects were caused by submental stimulation (Nam, Beom, Oh, & Han, 2013;Rofes et al, 2013).…”