Pathophysiology
The ‘three systems model’ The 'bladder–brain dialogue' The ‘Three Systems Model’ The model proposed by Butler and Holland [15] in 2000 provides a framework for understanding PMSE and helps conceptualise therapeutic interventions. PMSE is caused by one or more of the following three ‘systems’: NP associated with an abnormal circadian pattern of antidiuretic hormone (ADH)/arginine-vasopressin Overa
The ‘Three Systems Model’
The model proposed by Butler and Holland[15] in 2000 provides a framework for understanding PMSE and helps conceptualise therapeutic interventions. PMSE is caused by one or more of the following three ‘systems’:
- NP associated with an abnormal circadian pattern of antidiuretic hormone (ADH)/arginine-vasopressin
- Overactive bladder (OAB)/small-capacity bladder
- Lack of sleep arousal/abnormal sleep patterns.
The three systems model helps outline a management strategy:
- Children with NP with normal bladder capacity may respond to desmopressin (DDAVP) or the bed alarm.[16]
- Children with small bladder capacities for age are likely to be resistant to DDAVP; the alarm and/or anticholinergics can be considered.[17]
- For children with polyuria and reduced capacity, combination therapy may be successful.[18]
The ‘bladder-brain dialogue’
In their study, Yeung et al. [19] observed children with severe and refractory (refractory was defined as ≥5 wet nights per week) primary NE. They found that these children had a higher than expected cortical arousal index, resulting in failure to wake with a desire to void. The study concluded that the children had more light non-rapid eye movement sleep with frequent cortical arousals, but they could not wake up completely. It is speculated that complete awakening might be suppressed paradoxically by signals from the bladder through long-term overstimulation of the arousal centre.
The South African Medical Journal_The South African guidelines on enuresis: 2024 update_November 2024; Vol. 114, No. 11