The nocturnal intragastric pH in EEG sleep stages in peptic ulcer patients

In 10 peptic ulcer patients, 5 duodenal ulcer and 5 gastric ulcer patients, the relation of nocturnal intragastric pH to EEG sleep stages was examined. The nocturnal intragastric pH was monitored by pH-measuring telemeter and sleep stages were recorded simultaneously by electroencephalography throughout the night. The EEG sleep stages were classified after the criteria of Dement and Kleitman. The average of intragastric pH level at each sleep stage was higher in gastric ulcer than the duodenal ulcer. The intragastric pH level became low as the patients' sleep advanced to deep stage. This tendency was more likely in duodenal ulcer patients than the gastric ulcer patients, which indicated that the cephalic phase might play an important role in the pathogenesis of hyperacidity in duodenal ulcer.