Epilepsy and frequent nocturnal enuresis among children in Shanghai, China

Introduction Nocturnal enuresis (NE) is a common elimination problem that affects physical and psychological health of children older than 5 years, and more than 80% of them are primary. Frequent nocturnal enuresis (FNE) usually refers to involuntary urination more than 4 times a week during sleep. Children who frequently wet the bed are more likely to become adults with NE. The arousal dysfunction in response to micturition desire is the main pathogenesis of NE. Epilepsy is a common neurological disorder, which essentially reflects various diseases of brain dysfunction. Previous studies had suggested a possible association between epilepsy and NE.Objectives To examine the association between epilepsy and FNE and to investigate the related risk factors of FNE.Study design This was an in-depth analysis of a population-based cross-sectional study in Shanghai, China. There were 74 252 children aged 3-12 years old recruited using the multi-stage stratified cluster random sampling method. After ruling out 11 962 (16.1%) children aged less than 5 years, a total of 62 290 children were included in the study. They were surveyed for the demographic characteristics via questionnaires. In this study, IBM SPSS Statistics Version 23 was used for data analysis. Chi-square, t-test, univariable and multivariable logistic regression models were used.Results The epilepsy rate was significantly higher in children with FNE (2.1%) than that in children without (0.3%). After adjusting for confounding factors (sex, gestational age, birth weight, maternal age, academic performance, parent' education level, annual household income and autism spectrum disorder) in multivariable models, the incidence of epilepsy in children with FNE was 6.254 times higher than that in children without. Moreover, the adjusted OR was higher in girls than that in boys. Regarding age, the association between epilepsy and FNE existed exclusively among children aged 9-12 years.Discussion In the study, epilepsy was significantly associated with FNE, girls and preadolescent children were at higher risk. Puberty begins earlier in girls than in boys. Increased secretion of hormones might affect susceptibility to both epilepsy and FNE. It is hypothesized that persistent brain injury caused by multiple seizures may lead to progression to FNE in patients with NE. However, this was a preliminary investigation. The potential to diagnosis previously unrecognized epilepsy among children with FNE was not addressed by this study.Conclusion There was a significantly increased risk of epilepsy in children with FNE, especially in girls and preadolescent children.