Clinical significance of the cutaneous electrogastrogram

The electrogastrogram (EGG) is a measurement of gastric myoelectrical activity using surface electrodes placed on the abdomen. Though it was reported 70 years ago the progress of its clinical applicability has been very slow especially compared with ECG and EEG. The objective of this study was to investigate the clinical significance of the ECG using improved recording and data analysis techniques developed in our laboratory. Methods: Cutaneous EGGs were recorded in fasting (for 30 min) and fed (for 60 min) states from 24 healthy volunteers and 27 patients with motors disorders of the stomach. To achieve higher signal-to-noise ratio the position of the stomach was localized using ultrasonography, electrodes were placed on the abdomen right over the stomach and the abdominal skin was well prepared. Running power spectrum of each EGG signal was calculated every 2-min using an adaptive spectral analysis method based on autoregressive moving average modeling. The normality of the myoelectrical activity of the stomach was defined based on the running spectrum. Results; Normal myoelectrical activities were observed in all 24 normals both in fasting and fed states. In the patient group, however, 74% of the subjects showed different types of abnormalities: 4 had abnormal EGGs in both fasting and fed states, 7 had abnormal EGGs during fasting but normal EGGs after eating and 9 had normal EGGs during fasting but abnormal EGGs after eating. Conclusion; With the improved recording technique and the advanced adaptive spectral analysis method the cutaneous EGG is able to differentiate patients with gastric motor disorders from normal subjects.