Sensory and biomechanical properties of the esophagus in non-erosive reflux disease

Objectives. To investigate possible differences between patients with non-erosive gastroesophageal reflux disease (NERD) and controls in a) sensitivity of the distal esophagus after mechanical and thermal stimuli and b) the referred pain areas. Material and methods. Fifteen healthy subjects (mean age 39 +/- 19.4 years) and 13 NERD patients (mean age 44.4 +/- 21 years) were enrolled in the study. Pain evoked by mechanical and thermal stimuli was assessed using a newly designed multimodal stimulation probe. Results. The patients were less sensitive to mechanical stimulation as assessed by the cross-sectional area (p < 0.001) and volume (p = 0.007). After thermal stimulation, the patients were hypersensitive to heat stimuli (p = 0.04), whereas no significant difference was seen to cold stimuli. The referred pain areas were larger in patients compared with the pain areas in controls after mechanical (p = 0.03) and heat stimuli (p = 0.01), but not after cold stimuli. Balloon distension resulted in a significant higher number of reactive esophageal contractions in patients as compared with controls (p = 0.001). Conclusions. The present study showed that NERD patients were hypersensitive to heat stimuli of the esophagus, with an increase in referred pain to the evoked visceral pain. The data indicate that peripheral sensitization of heat-sensitive pathways together with facilitation of central pain mechanisms are important in the pathogenesis of NERD.