Effect of transcutaneous nerve stimulation on esophageal function in normal subjects--evidence for a somatovisceral reflex.

Transcutaneous stimulation (TNS) at esophageal acupuncture points decreases lower esophageal sphincter (LES) pressures in patients with achalasia. We examined the effect of TNS on esophageal motility and vasoactive intestinal peptide (VIP) levels in normal subjects. TNS was applied to either hand or foot (placebo) in 10 volunteers. Esophageal and LES pressures were recorded and blood was drawn for VIP analysis. Hand TNS improved LES relaxation and percent of peristaltic contractions to swallows, and decreased the number of spontaneous contractions. Foot TNS decreased only spontaneous contractions while LES pressures and VIP levels were unchanged. We conclude that a somatovisceral pathway involving the esophagus exists.