Electroencephalogram patterns during sleep reflux in infants

Twenty-four infants, 3-35 months of age, with histories of apnea or chronic lung disease underwent nighttime polysomnography and esophageal pH monitoring. Fifteen infants had pathological levels of gastroesophageal reflux on esophageal pH monitoring, and 9 had normal study results (symptomatic controls). Partition of sleep stages, sleep efficiency, and frequency of arousals to electroencephalographic stage 0 were the same in both groups. During sleeping reflux episodes, defined as reflux starting during sleep stages 1-5 or reflux episodes consisting of greater than 50% of sleep stages 1-5, there was a 50% decrease in the amount of stage 0 electroencephalogram pattern compared with nonreflux sleep, and a compensatory increase in the non-rapid eye movement sleep stages. Reflux onsets in patients with pathological reflux were evenly divided between stages 0, 1/2, and 5. Onset of reflux occurred rarely during sleep stages 3 and 4. Slight body movement accompanied the onset of 62.5% of sleep reflux episodes in symptomatic controls and 64.7% in patients with pathological gastroesophageal reflux. Arousals to stage 0 electroencephalogram occurred with equal frequency in sleep reflux episodes of symptomatic controls and patients, and frequency did not increase over the observed value for nonreflux time. There were no differences between the sleep patterns of infants with and without pathological gastroesophageal reflux; nor were there decreases in arousals from sleep in infants with pathological reflux. However, reflux occurring during sleep in all infants studied was characterized by a significant decrease in stage 0 (waking) electroencephalogram.