Edrophonium provocative testing during electrogastrography (EGG): effects on dyspeptic symptoms and the EGG

The aim of this study was to determine whether edrophonium induces dyspeptic symptoms and/or gastric myoelectric changes in normal subjects and patients with functional dyspepsia. Eighteen normal controls and 28 patients with functional dyspepsia underwent electrogastrography (EGG) with edrophonium administration. After EGG recording with 1-hr fasting and 2-hr postprandial periods, subjects received an intravenous infusion of saline (placebo) followed by edrophonium 10 mg. After each injection, the EGG was recorded for 15 min and symptoms scored. Patients with functional dyspepsia had significantly more frequent gastrointestinal symptoms in response to edrophonium than normal controls. Edrophonium had no effect on EGG dominant frequency, but increased the power of the dominant frequency in both controls and dyspeptic patients. In the dyspeptic patients, reproduction of the patient's symptoms was associated with an increase in the power of the dominant frequency, whereas when no symptoms were produced, there was no change in power. Overall, 21 of 28 dyspeptic patients (75%) had either an abnormal baseline EGG (N=10) or a normal EGG and positive edrophonium test (N=11). In conclusion, edrophonium administration can reproduce symptoms in some dyspeptic patients. Symptoms after edrophonium administration may be related to either more vigorous gastric contractions and/or increased visceral perception of normal gastric contractions.