Electromyography of the Esophagus

Abstract

Electromyographic examination of skeletal muscles with extracellular detec tion techniques has already been in clinical use for a long time. Several diseases of the muscles and their innervation cause a typical and often diagnostic electromyographic pattern. It may therefore be anticipated that the electromyographic exploration of the gastrointestinal tract also will come to clinical use. The electrical activity of stomach, small intestine and colon of animals has been studied intensively, both in vivo and in vitro, and has yielded important data on the regulation of the contraction patterns in these organs. Electromyographic examination of the esophagus, however, is of quite recent date. Christensen and Daniel (1966) used an in-vitro technique to study the electrical activity in strips of the longitudinal and circular muscle layer of the distal feline esophagus and found that spike potentials, which were sometimes superposed on slow waves, could be recorded upon contraction of these muscles. Roman (1966, 1967) studied the peristaltic mechanism of the sheep esophagus and observed that deglutition produced spike potentials which occurred immediately before the muscle contraction. Thèse data were later confirmed by Dougherty et al. (1971). Inouye (1966) studied the electrical activity of the esophagus of dogs and cats under general anesthesia. The esophageal deglutitive activity could not be studied under these experimental conditions. In addition to spontaneous spiking activity in the cricopharyngeal muscle, this author also noticed spike potentials in the lower segment of the esophagus, coinciding with inspiration.