Provoked enuresis-like episodes in healthy children 7 to 12-years old

Purpose: We evaluated whether a water load before bed time provoked enuresis episodes in healthy children with no previous enuresis. We also studied pelvic floor activity during an enuresis episode and the completeness of bladder emptying, attempted to identify a possible trigger mechanism for nocturnal enuresis, and investigated any age and sex differences regarding the frequency of provoked enuresis episodes. Materials and Methods: We evaluated 55 healthy volunteers (22 girls and 33 boys) 7 to 12 years old who were dry from age 5 years and had no urological or other complaints. Subjects were admitted to the hospital for 4 consecutive nights. Night 1 was for adaptation without a water load, On nights 2 to 4, 25 ml./kg. body weight of water were given orally half an hour before bedtime. During the night pelvic floor activity was monitored, and the time and volume of enuresis and nocturia episodes were noted. Results: In 17 subjects 25 enuresis-like episodes were provoked, generally comprising incomplete voidings with large residual volumes mostly in younger children and in boys. Enuresis and nocturia episodes were provoked at a volume specific for each individual without a relation to the bladder filling rate. Conclusions: Our results support the hypotheses that nocturnal polyuria is an important pathogenetic factor in enuresis and that arousal failure can be provoked in nonenuretic subjects.