Autonomic nervous system dysregulation in children with monosymptomatic nocturnal enuresis

Area of Science:

• Pediatric Nephrology
• Neuroscience
• Urology

Background:

• Childhood enuresis is common, with underlying mechanisms often linked to autonomic nervous system (ANS) dysregulation.
• Subtypes of enuresis, particularly those with and without nocturnal polyuria, may exhibit distinct pathophysiological pathways involving the ANS.

Purpose of the Study:

• To investigate the role of the autonomic nervous system in distinct subpopulations of children experiencing nocturnal enuresis.
• To differentiate the ANS contributions in children with enuresis presenting with nocturnal polyuria versus those without.

Main Methods:

• A cohort of 35 children with enuresis (17 with nocturnal polyuria, 18 without) and 43 healthy controls were studied.
• Hormone and neurotransmitter levels, sleep patterns via sleep trackers, 24-hour blood pressure monitoring, nocturnal urine output, and uroflowmetry were assessed.

Main Results:

• Children with enuresis showed lower copeptin and aldosterone compared to controls; aldosterone reduction was more pronounced in the non-polyuria group.
• Dopamine levels were lower in children without nocturnal polyuria compared to those with it.
• Enuretic episodes occurred during NREM sleep in the non-polyuria group, and during both REM and NREM sleep in the polyuria group. A non-dipping blood pressure pattern was observed in enuretic children, more so in the non-polyuria group.

Conclusions:

• Nocturnal enuresis with nocturnal polyuria is linked to sympathetic hyperactivity, pressure polyuria, and reduced systolic blood pressure dipping during sleep.
• Nocturnal enuresis without nocturnal polyuria appears associated with bladder overactivity from parasympathetic overstimulation, evidenced by NREM-related episodes and lower aldosterone/dopamine levels.