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Mechanisms of symptomatic improvement after gastric electrical stimulation in gastroparetic patients

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Errata

This article is corrected by:

  1. Errata: Erratum Volume 22, Issue 4, 491, Article first published online: 8 March 2010

  • Portions of the study were presented in abstract form at the 106th Annual Meeting of the American Gastroenterological Association, Chicago, IL, USA, May 14–19, 2005.

Richard W. McCallum MD, Founding Chair, Dept of Internal Medicine, Texas Tech University Health Sciences Center, Paul L. Foster School of Medicine, 4800 Alberta Avenue, El Paso, TX 79905, USA.
Tel: 915 545 6627; fax: 915 545 6634;
e-mail: richard.mccallum@ttuhsc.edu

Abstract

Abstract  The aims were to investigate the effects of gastric electrical stimulation (GES) on autonomic function, gastric distention and tone, and central control mechanisms in gastroparetic patients. Ten gastroparetic patients refractory to standard medical therapy participated in this study and data were collected at baseline, within two weeks before surgery for implantation of GES system, and at follow-up sessions between 6 and 12 weeks after GES therapy was initiated. In each session, electrocardiogram, electrogastrogram (EGG) and gastric barostat measurements were conducted before and after a caloric liquid meal. Positron Emission Tomography (PET) brain scans were performed on a separate day. During GES therapy there was a significant increase in the discomfort threshold for mean pressure from 21 mmHg at baseline to 25 mmHg at follow-up, and for mean volume from 561 mL to 713 mL. A significant increase in the postprandial EGG power (amplitude) was observed between baseline and follow up. The sympathovagal balance was significantly decreased after GES therapy, indicating a significant increase in vagal activity. The cumulative PET data showed an increase in quantitative radioactive counts relative to the standardized data base in both the thalamic and caudate nuclei after chronic GES therapy. We conclude that our data suggest that the symptomatic improvement achieved by GES in gastroparesis is best explained by activation of vagal afferent pathways to influence CNS control mechanisms for nausea and vomiting accompanied by enhanced vagal efferent autonomic function and decreased gastric sensitivity to volume distention which enhances postprandial gastric accommodation.

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