Objective: To study the mechanism of visceral hypersensitivity in patients with non-erosive gastroesophageal reflux disease (NERD) and to get further objective evidence in the abnormal alteration of the afferents involved in mediating esophageal sensation by cerebral evoked potentials (CEP).
Methods: We recruited 21 NERD patients and 10 normal healthy volunteers for the study. Mechanical distention stimulation was performed using a balloon-affixed polyvinyl multilumen catheter. First, maximally tolerated pain threshold of all subjects were recorded, then esophageal mechanical stimulation at an intensity of 75% maximum tolerated intensity and a frequency of 0.2 Hz was inflated in a total of 64 times by means of a computer-controlled barostat. The alternation of esophageal CEP was recorded before and after acid perfusion with a multi-channel international 10-20 system of electroencephalograph.
Results: Esophageal mucosal distention may evoke recognizable and reproducible multi-peak CEP. CEP morphology of the NERD patients was characterized by randomly distributed patterns and the peak latencies for N1, P1, and N2 were significantly shorter for mechanical stimulation as compared with the control group (respectively, P = 0.016, 0.003, 0.031), and the amplitude of the P1-N2 components was significantly increased in NERD patients (P = 0.03).
Conclusions: Characterization and alternation of CEP morphology and peak latencies and P1-N2 amplitudes elicited by esophageal distention in NERD patients provides evidence for defective hypersensitivity of afferent neural pathways and cortical processing.