Background: Brain potentials have been used to assess somatosensory, visual, and auditory function, whereas few attempts have been made to evoke brain potentials from viscera.
Methods: The present study evaluated perception and brain potentials evoked by electric stimulation at four different intensities in the esophagus of healthy volunteers. Results were compared with somatosensory evoked potential variables.
Results: In 6 of 10 subjects the two highest esophageal stimulus intensities caused a deep pain perception. A positive correlation between average esophageal stimulus intensity and age was demonstrated. The amplitude of brain potentials increased significantly as a function of both esophageal and cutaneous stimulus intensity. The latency of esophageally evoked potentials decreased with stimulus intensity and was substantially longer than cutaneously evoked potentials despite a comparable conduction distance.
Conclusions: The present methods provide possibilities to assess sensory mechanisms and perception related to the human esophagus.