566 CHAPTER 15 Pediatric urology
Non-neurogenic voiding dysfunction
Definition
This is an abnormal voiding pattern without an underlying organic cause (neurological disease, congenital malformation, or injury), which usually results in urinary incontinence (diurnal, nocturnal, or both). It is often associated with constipation and fecal retention.
Normal bladder control
•Neonates: Sacral spinal cord reflex triggers voiding when the bladder is full.
•Infants: Primitive reflexes are suppressed, bladder capacity increases, and voiding frequency is reduced.
•2–4 years: Development of conscious bladder sensation and voluntary control occurs.
Classification
Urinary incontinence can be divided into primary (never been dry) or secondary (re-emergence of incontinence after being dry for 6 months) types. Voiding dysfunction can be described as mild, moderate, or major.
•Mild: daytime urinary frequency syndrome; giggle incontinence; post-void dribbling (urine refluxes into the vagina, then dribbles into underwear on standing); nocturnal enuresis
•Moderate: lazy bladder syndrome (large capacity, poor contractility, infrequent voids); overactive bladder (detrusor overactivity associated with urgency and frequency). Children may demonstrate holding maneuvers (leg crossing, squatting, Vincent curtsey). There is increased risk of UTI, vesicoureteric reflux, and upper tract dilatation.
•Major: Hinman syndrome (non-neurogenic neurogenic bladder) involves dyscoordination between the bladder muscle and external urethral sphincter activity, resulting in a small, trabeculated bladder, VUR, UTI, hydronephrosis, and renal damage. It is caused by abnormal learned voiding patterns.
Evaluation
History
Enquire about UTIs; voiding habits (frequency, urgency, primary or secondary incontinence); family history; bowel problems; social history; and behavioral problems.
Examination
Conduct a full, noninvasive examination (palpable bladder or kidneys). Be vigilant for signs of sexual abuse in children with an atypical history (penile or vaginal discharge). Exclude an organic cause (hairy patch, lipoma, dimple on lower back may indicate lumbosacral spine abnormalities).
NON-NEUROGENIC VOIDING DYSFUNCTION 567
Investigations
Obtain urinalysis (infection, protein, glucose) and voiding diary and assess flow rate.
In selected cases, US of the renal tract (hydronephrosis, bladder size); VCUG (VUR, post-void residual), videourodynamics (over or underactive detrusor, sphincter dyssynergia), or MRI of the spine (if clinical suspicion of neurological cause) is indicated.
Management
This includes behavioral therapy (bladder retraining, timed voiding, change of voiding posture, psychological support); medication (antibiotics for infection, anticholinergics for bladder overactivity and urgency, laxatives or enemas for constipation); and intermittent catheterization to drain post-void residuals. Surgery is rarely indicated.
Prognosis
Fifteen percent of cases spontaneously resolve per year.
568 CHAPTER 15 Pediatric urology
Nocturnal enuresis
Enuresis is normal but involuntary voiding that occurs at an inappropriate time or social setting, during the day, night, or both. Nocturnal enuresis describes any involuntary loss of urine during sleep.
Prevalence
Approximately 750,000 children over age 7 years will regularly wet the bed. The prevalence in adults is ~0.5%.
Prevalence
Age (years) |
Females |
Males |
5 |
10–15% |
15–20% |
7 |
7–15% |
15–20% |
9 |
5–10% |
10–15% |
16 |
1–2% |
1–2% |
|
|
|
Classification
•Primary: never been dry for more than a 6-month period
•Secondary: re-emergence of bed wetting after a period of being dry for at least 6 months
Etiology
•Familial
•Delay in functional bladder maturation
•Altered antidiuretic hormone (ADH) secretion; abnormal decrease in ADH levels at night causes increased urine production (nocturnal polyuria)
•Altered sleep/arousal mechanism
•Psychological factors
•UTI (1% of cases)
Evaluation
•History: frequency of episodes; daytime symptoms; new or recurrent; family history; UTIs; bowel problems; psychosocial history
•Examination: exclude organic causes (neurological disease)
•Investigation: urinalysis (infection, specific gravity is reduced in nocturnal polyuria, glucose, protein); voiding diary
Management
Behavioral
Provide reassurance; bladder training; motivational techniques to improve the child’s self-esteem; conditioning therapy (an alarm is connected to the child’s underwear, which is triggered with the first few drops of urine).
NOCTURNAL ENURESIS 569
Pharmacological
•Imipramine—a tricyclic antidepressant with anticholinergic, antispasmodic properties.
•DDAVP or desmopressin (synthetic analogue of ADH) given intranasally or orally
Prognosis
Fifteen percent of patients have spontaneous resolution of symptoms per year.
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