CEREBRAL EVOKED-RESPONSES TO GASTROINTESTINAL STIMULATION IN HUMANS

Recent advances have permitted recording of evoked potentials (EPs) in response to electrical and mechanical stimulation of the gastrointest inal (GI) organs via methods used primarily in clinical neurophysiolog y. Current research involving stimulation of the esophagus, rectum, an d colon, and recording the corresponding responses on the scalp, is be ing practiced in only a few laboratories. This review examines the eng ineering aspects of recording EPs, such as characteristics of the stim uli, placement of stimulus electrodes in the GI tract, and enhancement of evoked potential signals. We also discuss the physiological concep ts involved in the generation of EPs, and how these compare with somat osensory evoked responses. Current experimental techniques employed by various investigators and results reported from their laboratories ar e compared. We believe that cerebral EPs to GI stimulation could be us eful in studying a number of pathophysiological conditions such as gas troesophageal reflux disease, diffuse esophageal spasm, chronic inflam matory bowel disorders, chronic abdominal pain, and irritable bowel sy ndrome, among others. We hope that the present review will generate in terest in the use of EPs arising out of GI stimulation, aiding in unde rstanding their physiological implications in healthy subjects and in GI disorders.