[Characteristics of cortical mapping in response to acid exposure in non-erosive reflux disease and erosive esophagitis using functional magnetic resonance imaging].

Objective: To investigate the brain mechanisms for esophageal visceral hypersensitivity.

Methods: Thirty-one non-erosive reflux disease (NERD) patients, 21 in the group of NERD with esophageal hypersensitivity (NERD-H) and 10 in the group of NERD with normal esophageal sensation (NERD-N), 13 patients with erosive esophagitis (EE), and 12 healthy volunteers, all sex- and age-matched, underwent whole brain blood oxygenation level dependent (BOLD) fictional magnetic resonance imaging (fMRI) to record the cortical fMRI response to intraesophageal perfusion of normal saline or dilute hydrochloric acid.

Results: The main centers affected in the NERD-H patients included the secondary somatosensory cortex (SII), primary somatosensory cortex (S1), right prefrontal cortex (PFC), right orbitofrontal cortex (OFC), insular cortex, amygdala, striatum, motor cortex and its supplementary area, and cerebellum cortices, which form part of the matrix controlling emotional, autonomic modulatory responses to pain. The peak fMRI signal intensity and average maximum percent signal increase in the regions of interest (ROI) at above-mentioned brain areas of the NERD-H group were significantly stronger than those of the NERD-N and control groups (all P < 0.01). The peak image intensity of the anterior cingulate gyrus (ACC) of NERD-H group was 562 +/- 104, significantly lower than that of the control group (587 +/- 126, P < 0. 05), but significantly higher than that of the EE group (535 +/- 91, P < 0.05). The timeline of activation and deactivation events of particular ROI differentiate the four groups. The initial image latency and peak fMRI latency after hydrochloric acid perfusion of the NERD-H patients were 1.7 min +/- 0.9 min and peak 4. 5 min +/- 1.3 min respectively, both significantly shorter than those of the NERD-N group (4.0 min +/- 1.1 min and 6.8 min +/- 1.6 min respectively, both P < 0.01) and those of the control group (5. 4 min +/- 1.7 min and 7.2 min +/- 1.5 min respectively, both P < 0.01). The range of deactivation of SII and R-PFC of the NERD-H group were 26.5% +/- 5.4% and 20.3% +/- 3. 0% respectively, both significantly greater than those of the NERD-N group (8.2% +/- 2.2% and 16.4% +/- 3.6% respectively, both P < 0.05) and those of the EE group (11.9% +/- 4.8% and 11.7% +/- 3.1% respectively, both P < 0.01). The range of deactivation in ACC of the control group was 16.9% +/- 2.5%, significantly greater than those of the NERD-H and EE groups (11.8% +/- 2.8% and 6.4% +/- 1.0% respectively, both P < 0.05).

Conclusion: The function of central nervous system to integrate and manage the convergence information becomes abnormal under the status of esophageal visceral hypersensitivity.