Dysfunctional Voiding in Children
Development of
Urethral Sphincter
Specific striated sphincter muscle closely applied to the smooth muscle at membranous urethra and mid-urethra
A ring shape sphincter in early adolescence, which account for initial high voiding pressure in infancy and early vesicoureteral reflux
An omega shape shincter in adolescence after development of urogenital septum

Congenital Abnormalities
Early detection and folic acid treatment markedly decrease spinal defects
Upper and lower motor bladder dysfunction and pelvic floor dysfunction may occur in thoracic or sacral lesions
Early prophylactic treatment of DESD by CIC, anticholinergics are beneficial



Lipomeningocele
Difficult to identify by physical examination, MRI is the best diagnostic method
Intradural lipoma results in disease and presentation
The most common urodynamic findings are consistent with an upper motor neuron lesion
DESD is less common
Detrusor hyperreflexia and areflexia can be found in this group of lesion

Sacral agenesis
Loss of the lower vetebral bodies by X-ray or MRI
Patients have stable neurological lesion
Patients may have no signs of denervation, hyperreflexia, areflexia, intact sphincter, sphincter dyssynergia

Isolated tethered cord is less common
Severe bladder dysfunction and refractory incontinence may occur
Surgical division of the filum may improve symptoms

Cerebral Palsy
Develops most commonly in premature infant
Infection and anoxia result in a non-progressive brain lesion and muscular disability
Continence is often delayed to develop but intact
Uninhibited detrusor contractions without DESD is the most commonly urodynamic finding
Pseudodyssynergia may occur

Bladder extrophy
Staged reconstruction by abdominal wall closure, epispadias repair, bladder neck reconstruction and correction of VUR
Improved pelvic floor reconstruction after osteotomy has better continence rate
Bladder augmentation may be indicated

Present with incontinence and recurrent UTI
Severe PUV may be detected antenatally, mild form is found in older children
Bilateral hydroureter and hydronephrosis may develop in severe form of valve disease
Transurethral ablation of valve resumes normal bladder but bladder function depends
Anticholinergics, CIC and augmentation by ureter may be indicated

Anorectal Malformations
Rare congenital lesions of cloaca
Associated with congenital GU abnormalities in 20% with low and 60% high lesions,VUR, NVD, renal agenesis, renal dysplasia, cryptorchidism
Urethrorectal fistula may develop at at high, intermediate or low level
Neurogenic voiding dysfunction in 50%
Tethered cord is the main vertebral abnormality, which account for NVD

Dysfunctional Voiding
A group of neurologically intact children presents with incontinence, dysuria, large residual urine, recurrent UTI, unilateral or bilateral hydronephrosis
Urodynamically classified into small capacity hypertonic bladder, detrusor hyperreflexia, lazy bladder syndrome,non-neurogenic neurogenic bladder
Treatment bases on interaction of bladder and external sphincter

Occurrence of UTI and antibiotics
Bowel habit, fecal incontinence, and stool softeners
Catheterization schedule, urine amount
Medication and adverse effects
Sacral dimple, hair patch, lipoma
Enlarged bladder
Vincent curtsey

Urodynamic study
Infusion rate: 10% of capacity
Catheter: <6Fr intraurethral dual channel catheter, suprapubic catheter is preferable for pressure flow study
Abdominal pressure by rectal catheter
Pelvic floor EMG – surface or needle
Measuring bladder compliance, detrusor pressure, and EMG activities coordination

Type 1: Onset of EMG activity with initiation of voiding
Type 2: intermittent inappropriate external sphincter contraction during voiding,which causes a reflex inhibition of detrusor contraction
Type 3: Persistent increased EMG activity during filling and voiding phases, which causes large residual urine and incontinence
Pseudodyssynergia: presence of urodynamic DESD in neurologically intact patient

Leak-point pressures
Detrusor leak-point pressure (DLPP): The detrusor pressure causing urinary leakage per urethrum in the absence of detrusor contractions
A DLPP of more than 40 cm water has a risk of upper tract deterioration
Valsalvar LPP (VLPP): Assessing urethral resistance by abdominal straining, a VLPP <60 cm water indicates intrinsic sphincter deficiency

Spinal dysraphisms
Sacral agenesis
Imperforated anus
Diurnal enuresis
Dysfunctional voiding

Uroflowmetry with surface EMG
Pressure flow study recording Pves,Pabd, Pdet, EMG activity, and uroflowmetry
Videourodynamic study by suprapubic catheter or intra-urethral catheter




Dysfunctional Voiding
Increased voiding pressure during voiding with contraction of the urethral sphincter
Dysfunctional bowel evacuation and constipation
Treatment directed at urodynamic abnormalities reduce the incidence of breakthrough UTI and increase resolution of vesicoureteral reflux

Pelvic laxity
Inappropriate stimulation of guarding reflex results in inhibition of detrusor contraction


Elevated postvoid residual urine
Host resistance – ability of bladder to wash out pathogens
Well hydration, void with strong stream, and complete voiding are important in prevention of UTI
Treatment aims at relaxation of the pelvic floor rather than the bladder


The severest form of dysfunctional voiding
Symptom complex including nocturnal enuresis, diurnal enuresis, constipation, encopresis, UTI, and upper tract dilatation
Uninhibited detrusor contractions and dyssynergic external sphincter

Voiding retraining
Play a major role in etiology of congenital VUR
Important in development of VUR in older child without congenital VUR
Responsible for reflux exacerbation and renal scarring
Therapy to VUR should aim at correction of dysfunctional voiding




Urodynamic studies in infants
High voiding pressures (160cm water) with low bladder capacity in infant with gross dilating reflux
Voiding pressure in infant without reflux is 80 cm water
By age 2 years, voiding pressure diminished (70 cm water) and capacity increased, but unstable detrusor remain

Boys with high grade reflux have dilated posterior urethra
Higher voiding pressure is seen in children with grades IV and V reflux
Normalization of voiding pressures explains high rate of reflux resolution in childhood

Up to 60% of children with reflux have urodynamic abnormality
Detrusor overactivity and sphincter dyscoordination
Primary sphincter overactivity is more associated with high grade reflux and renal scarring
Bladder instability improves over time

Poor cooperation of patient
Appropriate size of intra-urethral catheter – 3 Fr, 5 Fr, 7 Fr?
Frequent increased abdominal pressure

Treatment of detrusor overactivity with anticholinergics improves resolution or improvement in VUR than stable bladders
A higher surgery rate in stable bladder with VUR
Controversy remains in correlation of urodynamic abnormalities with grades of VUR and anticholinergic treatment with resolution rate of VUR

Resolution of VUR and improved DI after anticholinergic and CIC in myelomeningocele

Associated with an increased risk of urinary tract infection
With or without reflux
Incontinent day and night with fecal soiling
Observed to engage in holding maneuver to avoid urination and defecation

Most often occur in girls
Recurrent cystitis due to short urethra and bladder colonization
Congenital VUR or secondary VUR due to these aberrant toilet training habits

Breakthrough UTI and Dysfunctional voiding
Girls with history of voiding dysfunction have higher rates of breakthrough UTI (4 times more common in DES)
Unsuccessful surgical outcome was seen in children with DES
Adequate hydration, timed voiding, stool softeners, laxatives, as well as anticholinergics may be helpful

Children with mono-symptomatic enuresis have a very low urodynamic abnormality
VUR has been found in child with frequency urgency and urinary incontinence without history of UTI
15% of children had positive urodynamic findings and 16% had renal scarring



Adequate hydration and timed voiding
Stool softeners and laxatives
Intermittent catheterization
Improved bladder compliance and DI after ditropan therapy in myelomeningocele

Adequate hydration
Provide adequate urine production and wash out effect of bladder
Prevent constipation and reduce colonization of pathogen in perineum
Reduce detrusor instability through dilution of urine and decrease urine permeability into urothelium
Time voiding is required
Oxybutynin – effective in reducing detrusor overactivity, side effects of mucosal dryness & constipation
Ditropan XL – elimination of peak drug effect and reduce adverse effects
Tolterodine – M3 anticholinergic
Phenylpropanolamine, pseudoephedrine – in ISD with incontinence ready for CIC

Regular pelvic floor muscle exercises provide adequate relaxation of pelvic floor including urethral sphincter
A synergistic voiding pattern can be achieved after rehabilitation
Combined with fluid and anticholinergic therapy

Biofeedback for
Success relies on motivation of children Uroflow- surface EMG integrated biofeedback
Cystometry biofeedback to inhibit detrusor overactivity in patients with DI
Visual or audio biofeedback may be more successful than verbal biofeedback



New technique in reducing urethral resistance by paralyzing striated urethral sphincter
Intra-detrusor injection to reduce detrusor overactivity and increase bladder capacity
Restoration of normal voiding pattern
Repeat injection may be necessary