Autonomic Nervous System Function Changes during Arousals in Children with Primary Nocturnal Enuresis

Purpose: This study aimed to evaluate the autonomic nervous system functions of children with primary nocturnal enuresis during arousals and overnight sleep Material and methods: This prospective observational study included consecutive 27 children (15 boys and 12 girls, mean age: 9.8 ±2.2 years) with primary nocturnal enuresis and age- and gender-matched 27 healthy controls. All subjects were evaluated by overnight polysomnography, and the power spectrum analysis of heart rate variability (HRV) using Holter electrocardiograms for autonomic nervous system functions. The average values of HRV parameters during overnight sleep and the most intense 10 arousals were separately assessed. Results: There was no difference in any overnight average value of HRV parameter between children with nocturnal enuresis and the control group (for all, p<0.05). Five minutes before the most intense 10 arousals, the mean standard deviation of all normal-to-normal intervals was significantly lower in the nocturnal enuresis group, compared to the control group (85.0 ms vs. 107.0 ms, p=0.044). However, the mean square root of the mean of the sum of the squares of differences between adjacent NN intervals and total powers was significantly higher in the nocturnal enuresis group, compared to the control group (72.0 ms vs. 61.0 ms, p=0,001 and 4226.3 ms2 vs. 2745.7 ms2, p=0,008, respectively). Conclusion: This study showed the significant fluctuations of the short-term autonomic nervous system during the arousals periods in children with nocturnal enuresis. These fluctuations may be effective in the physiopathology of the disease.