Normal gastric antral myoelectrical activity in early onset anorexia nervosa

Anorexia, epigastric discomfort, nausea, and vomiting may result from disordered gastric motility and emptying. These features have been found in many adults with anorexia nervosa, but have never been investigated in early onset anorexia nervosa. In 14 patients with early onset anorexia nervosa (eight of whom had upper gastrointestinal tract symptoms), six children with other eating disorders, four children with non-ulcer dyspepsia, and 10 controls matched for age and sex, the non-invasive technique of surface electrogastrography was used to measure fasting and postprandial gastric antral electrical control activity, which underlies antral motility. The electrical signal was recorded by four bipolar silver/silver chloride electrodes attached to the upper abdomen, amplified and low pass filtered at 0.33 Hz before being displayed on a polygraph, digitised at 1 Hz, and stored on the hard disk of a personal computer for later offline analysis. Patients with non-ulcer dyspepsia had gastric antral dysrhythmias. No significant difference was found in the mean (SD) dominant frequency of the antral electrical control activity between patients with early onset anorexia nervosa (2.86 (0.35) cycles/minute (cpm)), patients with other eating disorders (3.14 (0.65) cpm), and controls (3.00 (0.46) cpm). The amplitude of electrical control activity increased postprandially in all but one subject and the fasting/postprandial amplitude ratio did not significantly differ between patients with early onset anorexia nervosa and controls, though patients with longer established disease had a smaller increase in amplitude. Gastric antral electrical dysrhythmias are not a feature of early onset anorexia nervosa and therefore do not induce or perpetuate food refusal in this disorder.