RESUMO
Objective To explore the effect of applying surface neuromuscular electrical stimulation (NMES) on the functioning of the upper esophageal sphincter (UES) using the high-resolution solid-state manometry.Methods Seventeen healthy volunteers were selected and given sham stimulation (SS),superior and inferior hyoid stimulation (SIHS),superior hyoid stimulation (SHS) or inferior hyoid stimulation (IHS) at a frequency of 80 Hz and the maximum tolerated level before swallowing.Any changes in the kinematics or biomechanics during swallowing and at rest were recorded using high-resolution solid-state manometry.One-factor repeated analysis of the measurement variance was used.Results A significant decrease in the duration of UES relaxation was observed in response to the electrical stimulation (compared with the sham stimulation).The UES's residual pressure showed a rising trend during electrical stimulation,especially in response to IHS,but the difference compared with SS was not significant.The UES's resting pressure during SIHS increased significantly compared with SS,but there was no significant difference between SHS and IHS in this respect.Conclusions Surface neuromuscular electrical stimulation applied to the neck can immediately change the functioning of the UES.NMES at the maximum tolerated intensity can reduce the duration of UES relaxation,which is important for dysphagia therapy and research.