AUTHOR AND EDITOR INFORMATION

Section 1 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

INTRODUCTION

Section 2 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Background

Idiopathic overactive bladder (OAB) is a term that has been adopted by the International Continence Society (ICS) to describe the symptom complex of urinary urgency, which may or may not be associated with urgency urinary incontinence, urinary frequency, and nocturia in the absence of pathologic or metabolic factors that cause or mimic these symptoms.¹ In the pediatric literature, OAB is often referred to as -urge syndrome and is best characterized by frequent episodes of an urgent need to void, countered by contraction of the pelvic floor muscles and holding maneuvers such as squatting and the Vincent curtsy sign.

The cardinal symptom of OAB is urgency, which is defined as a sudden compelling desire to void that is often difficult to defer. Urgency must be differentiated from the urge to void, which is a normal sensation experienced by all individuals and may be intense when urine is held for a prolonged period. The definition of urinary frequency in a child is not well-established. However, many believe that a child who has a normal fluid intake and who voids more than 7 times per day has urinary frequency. The ICS defines nocturia as the need to wake at night one or more times to void.

Depending on fluid intake and urine production, children may experience more episodes of incontinence later in the day due to fatigue and an impaired ability to concentrate. In some cases, children with OAB remain dry during the day yet wet at night. However, such children experience daytime urgency and, often, daytime frequency.

Pathophysiology

The symptoms of OAB are believed to be caused by detrusor overactivity during the filling phase, causing urgency (see Image 1). These detrusor contractions are countered by voluntary contraction of the pelvic floor muscles in an attempt to postpone voiding and to minimize wetting. The voiding phase is essentially normal but may be associated with a powerful detrusor contraction during voiding.

The natural history of OAB is not well-understood. Many believe that idiopathic OAB in children is the result of a maturation delay and that it resolves over time. This belief is in contrast to the theory behind OAB in adults, in whom the condition is believed to be chronic.

Frequency

United States

The prevalence of OAB in children is difficult to determine, as studies have focused primarily on daytime versus nighttime incontinence and have not attempted to differentiate the type of daytime incontinence. In a population survey of 1,192 individuals aged 1.5 to 27 years, diurnal accidents occurred in 13% of children aged 4 years, 7% of children aged 5 years, 10% of children aged 6 years, and 5% of children aged 7 years.²

International

Studies performed outside the United States have demonstrated that 2-4% of 7-year-old children have daytime or combined daytime and nighttime incontinence at least once per week and that it is more common in girls than in boys.³ In a population-based study of children aged 4-6 years in Australia, 19.2% had at least one daytime wetting episode in the preceding 6 months, with 16.5% having experienced more than one wetting episode and only 0.7% experiencing wetting on a daily basis.⁴ Up to 50.7% of children with daytime wetting have been noted to have urgency, with 79% wetting themselves at least once in a 10-day period.⁵

Mortality/Morbidity

Children with OAB have an increased risk of urinary tract infections (UTIs), which may be related to damage to the bladder mucosa during powerful detrusor contractions. In addition, frequent voluntary contractions of the pelvic floor muscles may also lead to postponement of defecation. Constipation and fecal soiling are often identified in children with OAB.

In addition, symptoms of pediatric OAB and urinary incontinence may lead to embarrassment in the child. The child may be inappropriately labeled as having a psychologic problem. Children with OAB may refrain from social activities, in fear of wetting and of letting others know how frequently they void. Difficulties may develop between the child and the child's peers, parents, or both.

Sex

Hellstrom et al (1990) assessed the prevalence of urinary incontinence in 7-year-old Swedish children.⁶ Diurnal incontinence was more common in girls (6.7%) than in boys (3.8%) . Wetting every week was reported in 3.1% of girls and in 2.1% of boys. Most children with diurnal incontinence had other symptoms. Urgency was reported in 4.7% of girls and in 1.3% of boys.

Age

Urge symptoms seem to peak in children aged 6-9 years and to diminish as they approach puberty, with an assumed spontaneous resolution rate for daytime wetting of 14% per year.^{7, 8}

CLINICAL

Section 3 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

History

The clinical presentation of overactive bladder (OAB) in children is similar to that in adults. The clinical features include urgency, urinary frequency, urinary urge incontinence, and nocturia or nocturnal enuresis.

• Children often exhibit various behaviors to prevent urinary leakage, including squatting behaviors and the Vincent curtsy sign.
• Children may have a history of recurrent UTIs and constipation.
• A careful voiding and bowel history, as well as a review of fluid intake (including type of fluid), is important to note.
• In girls, voiding habits should be reviewed to ensure proper positioning during voiding to eliminate vaginal reflux voiding as a source of incontinence.

Physical

Physical examination findings are usually normal in children who have idiopathic OAB.

• Children with urinary incontinence may have perineal excoriation.
• A focused neurologic examination should be performed to rule out an underlying neurologic etiology. The examination includes an assessment of perineal sensation, assessment of the perineal reflexes supplied by sacral segments S1-S4 (standing on toes, bulbocavernosus reflex), evaluation of anal sphincter tone, and evaluation of the buttocks, legs, and feet for signs of occult neurospinal dysraphisms of the lumbosacral area.
• The position and caliber of the urethral meatus should be inspected.
• The abdominal examination should include assessment for a distended bladder and a full sigmoid/descending colon suggestive of constipation.
• The sacrum should be palpated to ensure that it is present and the presacral area inspected for dimples, abnormal gluteal clefts, hairy patches, and other signs of possible neurologic lesions.

Causes

In children, OAB may arise from various etiologies, including neurogenic, anatomic, inflammatory, and idiopathic causes. Neurogenic etiologies include myelomeningocele, cerebral palsy, spinal cord injury, sacral agenesis, and imperforate anus. Twenty-two percent of children with a lumbosacral myelomeningocele have uninhibited bladder contractions.⁹ In children with cerebral palsy, an unstable bladder is the most common urologic anomaly.

The most common anatomic abnormality associated with OAB is posterior urethral valves; 24% of males with this condition have OAB.¹⁰ Inflammatory processes in the bladder wall (eg, UTIs) may irritate receptors in the submucosa and detrusor muscle layers and may lead to OAB symptoms. Idiopathic OAB is thought to be secondary to delayed maturation of the reticulospinal pathways and inhibitory centers in the midbrain and cerebral cortex.

DIFFERENTIALS

Section 4 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Other Problems to be Considered

Voiding Dysfunction
Urinary Tract Infection
Renal Glucosuria

Differential diagnoses for overactive bladder (OAB) include dysfunctional voiding and voiding postponement. A careful history, physical examination, uroflow study, bladder scan, and measurement of postvoid residual volume help differentiate the conditions (see Image 2).

• Dysfunctional voiding refers to an inability to fully relax the urinary sphincter or pelvic floor muscles during voiding. Unlike detrusor-sphincter dyssynergia, people with dysfunctional voiding do not have an underlying neurologic abnormality.
• • Children with dysfunctional voiding typically present with a history of urinary incontinence, recurrent UTIs, and constipation.
  • Although thought to be primarily a voiding phase disorder, dysfunctional voiding may develop in some children with OAB because of overactivity of the pelvic floor muscles in response to attempts to control uninhibited detrusor contractions.
  • In most children, however, it is believed to be a learned condition that occurs during the toilet-training years. It may develop after episodes of dysuria, UTIs, constipation, or prior sexual abuse. These children typically have either a staccato voiding pattern characterized by periodic bursts of pelvic floor muscle activity during voiding and a prolonged voiding time or an interrupted voiding pattern characterized by incomplete and infrequent voiding with micturition in separate fractions (see Image 3).
• The term voiding postponement is a new classification of voiding dysfunction proposed by Lettgen et al.¹¹ In this condition, children postpone urination until overwhelmed by urgency, forcing them to rush to the toilet.
• • Leakage often occurs on the way to the toilet.
  • Initially, this disorder was attributed to detrusor overactivity. However, clinically significant behavioral symptoms were found to be more common in children with voiding postponement, suggesting more of a behavioral etiology.
  • These children tend to relax their pelvic floor muscles when voiding; thus, most of these children have a normal uroflow pattern, and only 20% have a staccato pattern.¹¹

WORKUP

Section 5 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Lab Studies

• Noninvasive diagnostic techniques are often used in the diagnostic evaluation of overactive bladder (OAB).
• All children who present with OAB symptoms should undergo urinalysis to rule out underlying UTI or glucosuria.

Imaging Studies

• Ultrasonography of the kidneys and bladder is useful in assessing renal size, cortical thickness, hydronephrosis, and duplicated collecting systems and associated anomalies (ectopic ureters and ureteroceles). Ultrasonography of the bladder may be obtained prevoid and postvoid to assess bladder emptying. In addition, determination of bladder-wall thickness may be useful. A bladder wall cross-section of more than 3-4 mm measured at 50% of expected bladder capacity suggests underlying detrusor overactivity.
• Videourodynamic studies are urodynamic studies performed with fluoroscopic assistance. The addition of fluoroscopy allows for the detection of vesicoureteral reflux, a spinning-top urethra (often seen in girls with dysfunctional voiding), and other anatomic abnormalities.
• In children with neurologic abnormalities or a sacral dimple or other presacral abnormality, MRI of the lumbosacral spine should be considered.
• Voiding cystourethrography (VCUG) is indicated in children with a history of a febrile UTI or recurrent UTIs, depending on age, to rule out vesicoureteral reflux.
• • VCUG may also be indicated in a child with an abnormal flow pattern to rule out bladder outlet obstruction (ie, posterior urethral valves, stricture, syringocele).
  • A spinning-top dilated proximal urethra revealed by VCUG during the voiding phase suggests detrusor-sphincter dysfunction.

Other Tests

• A frequency/volume chart or bladder diary is helpful in the evaluation of pediatric OAB symptoms.
• • A frequency/volume chart is used to record the volumes voided and the time of each micturition, day and night, for at least 24 hours.
  • A bladder diary is used to record the times of micturitions and voided volumes, incontinence episodes, pad usage, and other such information as fluid intake, the degree of urgency, and the degree of incontinence.
  • A record of the bowel frequency and any fecal soiling is also helpful.
  • Ideally, the chart should encompass a 3-day period. This chart allows assessment of the child's functional bladder capacity.

Procedures

• In most children, noninvasive tests alone are used to diagnose OAB.
• Indications for invasive testing include the following:
• • Straining or use of the Credé maneuver during voiding
  • Weak or decreased urine stream
  • Previous febrile UTI
  • Continuous dribbling incontinence
  • Stress incontinence
  • Prior history of vesicoureteral reflux
  • Structural abnormalities on physical examination suggestive of an underlying neurologic etiology
  • Suspected obstruction
• A uroflow study is also helpful in the assessment of OAB symptoms and is performed by having the child void into a specialized collection device. The uroflow study can be described in terms of flow rate (mL/s) and flow pattern.
• • The flow may be continuous, intermittent (interrupted), or staccato (flow does not completely stop but fluctuates because of incomplete relaxation of the sphincter).
  • Obtain several uroflow studies to achieve consistency. Ninety-nine percent of school children have a bell-shaped flow curve, whereas the remaining 1% have an abnormal flow curve. Such abnormal flow curves include flattened or intermittent flow curves.
  • For a urinary flow rate to be useful, the voided volume should be at least 50% of the child's functional bladder capacity. Before starting the study, a bladder scan may be helpful in determining the bladder volume.
• A uroflow/electromyography (EMG) study involves the placement of perineal electrodes (often patch electrodes) and measurement of EMG activity before, during, and after voiding.
• • Normally, sphincteric activity occurs during bladder filling but silences during voiding.
  • Failure of relaxation or increased sphincteric activity during voiding may suggest a neurologic abnormality or dysfunctional voiding.
• Postvoid residual volume determination is useful in ruling out dysfunctional voiding as a source of symptoms. In children, except in small infants, the bladder completely empties during each micturition.
• • An increased postvoid residual volume may be secondary to dysfunctional voiding.
  • Initially, if the postvoid residual volume is increased, the study should be repeated because the results may not be accurate in an anxious child.
• A urodynamic study is an invasive study that should be obtained only in select children with voiding dysfunction.
• • Before performing this study, the child and parents should be fully aware of what the study entails. If the child is very anxious during the study, the results may be affected, especially during the filling cycle (detrusor overactivity may be noted) or during voiding (incomplete pelvic floor muscle relaxation may be noted).
  • The urodynamic study has several components. The child is first asked to void just before the study is begun. A sterile urodynamic catheter is then placed via the urethra into the bladder, and the postvoid residual volume is recorded.
• The cystometrography (CMG), also known as filling cystometry, is the component of the urodynamic study that is used to assess the bladder during filling. A CMG provides information on the pressure/volume relationship of the bladder during bladder filling.
• • The bladder should be filled with body-temperature 0.9% sterile saline at a rate of 5-10% of the child's expected bladder capacity per minute to a maximum rate of 10 mL/min.
  • Contrast material may also be used if fluoroscopic imaging is planned.
  • The bladder capacity is measured during filling cystometry. The cystometric bladder capacity is the bladder volume at the end of the filling CMG, when the child is given permission to void.
  • The cystometric capacity is the volume voided together with any residual volume. The maximum cystometric capacity in patients with normal sensation is the bladder volume at which the patient feels that he or she can no longer delay voiding (strong desire to void).
  • The term bladder compliance refers to the relationship between the change in bladder volume and the change in detrusor pressure.
  • The International Continence Society recommends that 2 standard points be used for compliance calculations: (1) the detrusor pressure at the start of bladder filling and the corresponding bladder volume (usually zero) and (2) the detrusor pressure (and corresponding bladder volume) at cystometric capacity or immediately before the start of any detrusor contraction that causes significant leakage.¹
  • Detrusor overactivity is a urodynamic observation characterized by involuntary detrusor contractions during the filling phase, which may be spontaneous or provoked (see Image 1).
  • Different patterns of detrusor overactivity may be noted.
  • • Phasic detrusor overactivity is defined by a characteristic wave form and may not lead to urinary incontinence.
    • Terminal detrusor overactivity is a single involuntary detrusor contraction occurring at cystometric capacity. It cannot be suppressed and results in incontinence, usually resulting in bladder emptying (voiding).
    • Detrusor overactivity incontinence due to an involuntary detrusor contraction at any point during filling.
• Pressure-flow studies may be obtained during the voiding phase of the urodynamic study. The pressure-flow study involves the plotting of the bladder pressure against flow-rate. This study may be useful when urinary obstruction is suspected.

TREATMENT

Section 6 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Medical Care

Many of the signs and symptoms of overactive bladder (OAB) are due to faulty perceptions of bladder signals and habitual nonphysiologic responses to these signals.¹² The etiology of OAB in children is unclear but may be related to a maturational delay in the central nervous system.

Some of the consequences of OAB result from the child's voluntary attempts to maintain continence during the involuntary detrusor contractions. These coping mechanisms, including forceful contractions of the external sphincter and squatting maneuvers to produce perineal compression, may lead to functional and morphologic changes in the bladder, which can increase the child's risk of UTIs and vesicoureteral reflux. Contraction of the pelvic floor muscles may also increase the risk of constipation.

As with adults, older children often institute various coping strategies, including defensive voiding, toilet mapping, and restriction of fluid intake. Thus, the management of OAB must consider not only the detrusor overactivity but also the responses to it.

The initial management of OAB involves a behavioral and cognitive approach. The child and caregiver must be educated on normal bladder and sphincter function.

Constipation, if present, must be treated. UTIs should be treated and, depending on the child's age and whether the UTIs have been febrile or nonfebrile, investigated further with renal ultrasonography and VCUG. In children with recurrent UTIs, the use of antibiotic prophylaxis may be helpful in decreasing the number of infections while voiding and bowel habits are being managed. Nitrofurantoin or trimethoprim-sulfamethoxazole at one third to one half of the normal treatment dose administered once per day is the typical choice for prophylaxis.

If behavioral therapy fails or the child has severe symptoms, pharmacologic therapy is instituted. See Medication.

Botulinum toxin is currently being used to treat pediatric detrusor overactivity, particularly cases with a neurogenic cause. Botulinum toxin interacts with the protein complex necessary for the release of acetylcholine and other transmitters from the presynaptic nerve endings and prevents the release of the transmitters from the presynaptic vesicles. This effect results in decreased muscle contractility and atrophy at the injection site. The initial results in children seem promising, but researchers need to perform additional studies on this treatment approach.

• In children, a total of 50-100 IU, on average, is injected in 30-40 bladder sites. The results last 6-9 months.¹³
• The use of botulinum toxin in children is limited by the need for preinjection anesthesia and the need for repeat injections.
• Few data are available regarding the dose, concentration, site or sites, number of injections, long-term efficacy, and side effects in both adult and pediatric patients with OAB.
• In adults, generalized weakness and development of resistance to the toxin has been reported.

Surgical Care

Although neuromodulation is used more commonly in adults, this treatment approach has been used in children in whom behavioral and pharmacologic therapy fails. The exact mechanism by which neuromodulation affects detrusor overactivity is not fully understood. Sacral nerve stimulation may induce reflex-mediated inhibitory effects on the detrusor through afferent and/or efferent stimulation of the sacral nerves. In addition, stimulation of the somatic fibers of the nerves may activate the pelvic floor muscles, causing further detrusor inhibition.¹⁴

The procedure requires surgery; thus, many parents are reluctant to proceed. In addition, the current version of the device is relatively large for a child, so this procedure may be more attractive to parents when a smaller device becomes available.

Transcutaneous stimulation has been used in children. This involves placement of surface electrodes to stimulate the sacral root (S3). Several stimulation frequencies have been used, and stimulation of 2 Hz seems to be sufficient. Researchers have not yet determined the optimal length of each stimulation during a treatment session nor how many sessions the treatment should continue.¹⁵

Surgical procedures such as bladder augmentation or autoaugmentation are rarely needed in children with idiopathic OAB but may be indicated in children with neurogenic OAB refractory to medical therapy.

Diet

Dietary changes are helpful in some children, particularly those who drink caffeinated or acidic fluids and those with increased fluid intake.

MEDICATION

Section 7 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Although pharmacologic therapy is one of the mainstays in the treatment of adult overactive bladder (OAB) and the management of neurogenic detrusor overactivity, its role in the treatment of idiopathic OAB in children is less well-defined.

The use of anticholinergic therapy in the management of OAB is predicated on the concept that parasympathetic mediated stimulation of muscarinic receptors (M3 primarily) in the bladder leads to detrusor overactivity. Anticholinergic/antimuscarinic agents have been demonstrated to increase bladder capacity, to improve bladder compliance, and to decrease uninhibited detrusor contractions.

Anticholinergic agents are often used in children with OAB when behavioral therapy has failed or as an adjunct to behavioral therapy. Despite the frequent use of anticholinergic agents in children with OAB, few randomized studies have assessed the drug safety and efficacy. In a recent Cochrane review of all randomized controlled trials for the treatment of daytime incontinence in children from 1996-2001, only 5 trials were found to compare 2 or more interventions using a randomized controlled design. Of these 5 studies, 4 evaluated the use of pharmacologic agents. Of the 4 pharmacologic studies, 2 evaluated the use of terodiline (no longer available), one evaluated imipramine, and one evaluated oxybutynin.¹⁶

Currently, the most commonly used anticholinergic for the treatment of OAB in children is oxybutynin (Ditropan XL). Ditropan XL is a once-a-day formulation that is available and approved for use in children who can swallow a pill and who meet the drug's age requirements.¹⁷ Historically, oxybutynin use has been limited by side effects, most notably dry mouth and constipation. In addition, the need for 2– and 3–times-a-day dosing may affect compliance. The extended-release preparation decreases such side effects. The risk of side effects appears to be dose-related. Both oral oxybutynin and intravesical oxybutynin may cause central nervous system and cognitive function side effects.^{18, 19} However, such reports have not been documented with Ditropan XL.

Ditropan XL is delivered via the osmotic release oral system (OROS). The tablet cannot be crushed, cracked, or chewed and must be swallowed whole. Oxybutynin is metabolized by the cytochrome P450 enzyme systems, particularly the CYP3A in the liver and gut wall. The pharmacokinetics of Ditropan XL were evaluated in 19 children aged 5-15 years with neuropathic detrusor overactivity and were found to be consistent with those reported for adults.

The contraindications to Ditropan XL use in children are the same as those in the adult population (ie, urinary retention, severe decreased gastrointestinal motility conditions, uncontrolled narrow angle glaucoma). Caution should be used in treating patients with severe hepatic impairment and those on potent CYP3A4 inhibitors.

In a 24-week open-label trial, the safety and efficacy of Ditropan XL was studied in 60 children aged 6-15 years with neuropathic detrusor overactivity. The study demonstrated that Ditropan XL in doses ranging from 5-20 mg was demonstrated to yield an increase from baseline in mean urine volume per catheterization and an increase from baseline in the mean percentage of catheterizations without a leaking episode. Urodynamic results were found to be consistent with clinical results (Prescribing Information, Alza Corporation/Ortho-McNeil).

The recommended initial starting dose of Ditropan XL in children aged 6 years or older is 5 mg/d. The dosage may be increased in 5-mg increments up to a maximum of 20 mg/d to achieve a balance of efficacy and tolerability. Side effects of Ditropan XL are those commonly encountered with anticholinergic agents, including dry mouth, constipation, facial flushing, central nervous system effects (headache, dizziness, somnolence), and blurred vision. The incidence of side effects with Ditropan XL is significantly lower than with oxybutynin, particularly with respect to dry mouth and constipation.

Other agents used in the treatment of adult OAB have been used in children. Tolterodine (Detrol), a nonselective antimuscarinic agent with a favorable tolerability profile compared with oxybutynin, has been studied in children. However, no pediatric indication is listed in the labeling. Tolterodine is metabolized in the liver, and the active metabolite has a therapeutic effect that is similar to that of oxybutynin. The pharmacokinetics of tolterodine in children have not been established (Prescribing Information, Pfizer).

Because tolterodine is metabolized by the liver, care should be taken with agents that affect CYP2d6 and CYP3A4 activity, and practitioners should adjust dosage in patients with severe liver disease. Tolterodine is contraindicated in patients with urinary retention, gastric retention, uncontrolled narrow-angle glaucoma, or documented hypersensitivity to the drug or its ingredients. Safety and efficacy studies performed in European children on doses ranging from 0.5-2.0 mg PO bid for 14 days demonstrated a 21% mean decrease from baseline in micturition frequency and a 44% mean decrease from baseline in the number of incontinence episodes among children treated with 1 mg PO bid.²⁰

The efficacy of tolterodine in pediatric patients has not been determined. The results of 2 pediatric phase III, placebo-controlled, double-blind, 12-week studies demonstrated aggressive, abnormal, and hyperactive behavior and attention disorder in 2.9% of children treated with Detrol LA compared with 0.9% treated with placebo. The most common adverse events related to tolterodine use include dry mouth, constipation, headache, vertigo/dizziness, and abdominal pain. Patients also reported abnormal vision (accommodation abnormalities), an expected side effect of an antimuscarinic agent.

Trospium chloride (Sanctura), another agent used in adults, has been used in a small series of children, with doses varying from 10-25 mg/d, divided bid. Overall, 32% of patients had an excellent response to the drug, 42% a good response, and 8% a fair response. Detrusor overactivity completely resolved in 35% of the children.²¹ Trospium chloride is currently approved for use in the United States for adults in a dose of 20 mg PO bid. No dosing guidelines or safety and efficacy information are available for trospium chloride use in children.

Other newer anticholinergic agents used in adult patients with OAB that have not been studied in children include solifenacin (Vesicare) and darifenacin (Enablex).

Drug Category: Anticholinergic agents

These drugs inhibit the binding of acetylcholine to the cholinergic receptor, thereby suppressing involuntary bladder contraction of any etiology. In addition, they increase the volume of the first involuntary bladder contraction, decrease the amplitude of the involuntary bladder contraction, and may increase bladder capacity.

FOLLOW-UP

Section 8 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Further Outpatient Care

• Voiding regimens are instituted in all children with overactive bladder (OAB). Voiding is recommended every 2-3 hours while the child is awake. This often requires assistance from teachers to ensure that the child is complying with a voiding regimen at school.
• In children who do not empty their bladder completely (increased postvoid residual), the practitioner should institute a double voiding regimen, whereby the child voids and then waits a minute or two and tries to void again to improve bladder emptying.
• In children who fail to improve with such behavioral therapies, biofeedback therapy and pharmacologic therapy are the next treatment options.
• • Biofeedback is a technique in which physiological activity is monitored, amplified, and conveyed to the patient as a visual or acoustic signal, providing the patient information about unconscious physiological processes.
  • Biofeedback has been used for both filling-phase (detrusor overactivity) and voiding-phase (dysfunctional voiding) abnormalities.
  • Biofeedback can help children identify and suppress involuntary detrusor contractions, as well as identify and relax their pelvic floor muscles.
  • The limitation of biofeedback in the management of detrusor overactivity is the need for the placement of a catheter and the potential need for multiple sessions.
  • In children with associated pelvic floor dysfunction, biofeedback may be performed via the use of a uroflow with EMG. The EMG activity can be identified on the monitor and followed as the child first locates and then learns to relax his or her pelvic floor muscles.
  • Few studies have evaluated urodynamic-based biofeedback in children with detrusor overactivity. The small numbers of patients and the variability in study design limit the value in drawing conclusions.
  • Kjolseth et al performed cystometrogram-assisted biofeedback in 15 children aged 6-12 years with idiopathic detrusor overactivity. The children received 1-2 inpatient sessions, and follow-up sessions were determined by the severity of the child's symptoms and the ease of learning for the child. A pronounced improvement was noted in 60% of children, and some improvement was noted in 13% of them. The children were monitored for up to 2 years after the end of therapy, and, in all children but one, the beneficial effects were maintained.²²

In/Out Patient Meds

• Although the urodynamic effects of anticholinergic agents occur within 24 hours of dosing, the clinical effects tend to take longer. The authors recommend that an individual remain on an anticholinergic agent for at least 2-4 weeks before determining whether the medication is effective. Furthermore, in individuals who note some response to therapy, improvement may increase throughout the first month of therapy. Thus, the effectiveness of the medication should be evaluated.
• Behavioral therapy is an important component in the management of OAB, and clinicians should ensure that such regimens are being followed for maximal response.
• In children who respond to anticholinergic therapy, the child should remain on therapy for 3-6 months before attempting to wean off the therapy. If the weaning fails, the child should return to the dose that kept his or her symptoms controlled for an additional 3-6 months before attempting another trial of weaning.
• In children who are refractory to behavioral therapy and anticholinergic therapy, further evaluation is indicated. Urodynamic studies are helpful to evaluate bladder and sphincteric function in these children. In addition, children who do not respond to therapy should be re-assessed to rule out an underlying neurologic etiology.

Prognosis

• The natural history of OAB in children is unknown. Similarly, limited information regarding the optimal duration of therapy is available. OAB in children is not believed to be a chronic condition; however, little long-term information is available.
• Curran et al described the long-term results of conservative treatment in children with idiopathic detrusor overactivity. In this study, the average time to resolution of symptoms was 2.7 years. The authors noted that children with very small or large bladders were less likely to benefit from conservative management. Age and gender were not significant predictors of resolution, although symptom resolution was more likely in girls than in boys.²³

Patient Education

• Both the patient and his or her parents or caregivers must be educated on normal bladder and sphincter function.

MISCELLANEOUS

Section 9 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Medical/Legal Pitfalls

• The diagnosis of idiopathic overactive bladder (OAB) requires that a focused history and physical examination, as well as a urinalysis, be performed to rule out conditions that may mimic or cause OAB. Failure to identify an underlying neurologic condition may lead to persistent symptoms.
• In children with neurologic abnormalities or a sacral dimple or other presacral abnormality, consider MRI of the lumbosacral spine.

FURTHER READING

Section 10 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

For additional information, see Medscape’s Urinary Incontinence & OAB Resource Center.

MULTIMEDIA

Section 11 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

Media file 1:  A urodynamic study demonstrating detrusor overactivity.
	View Full Size Image
Media type:  Rhythm Strip

Media file 2:  Differential diagnoses of overactive bladder (OAB).
	View Full Size Image
Media type:  Graph

Media file 3:  Uroflow and electromyography (EMG) study demonstrating dysfunctional voiding: staccato flow pattern and failure to relax sphincter during voiding.
	View Full Size Image
Media type:  Rhythm Strip

REFERENCES

Section 12 of 12

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Further Reading
• Multimedia
• References

1. Abrams P, Cardozo L, Fall M, Griffiths D, Rosier P, Ulmsten U, et al. The standardisation of terminology of lower urinary tract function: report from the Standardisation Sub-committee of the International Continence Society. Neurourol Urodyn. 2002;21(2):167-78. [Medline].
2. Bloom DA, Seeley WW, Ritchey ML, McGuire EJ. Toilet habits and continence in children: an opportunity sampling in search of normal parameters. J Urol. May 1993;149(5):1087-90. [Medline].
3. Kuh D, Cardozo L, Hardy R. Urinary incontinence in middle aged women: childhood enuresis and other lifetime risk factors in a British prospective cohort. J Epidemiol Community Health. Aug 1999;53(8):453-8. [Medline].
4. Sureshkumar P, Craig JC, Roy LP, Knight JF. Daytime urinary incontinence in primary school children: a population-based survey. J Pediatr. Dec 2000;137(6):814-8. [Medline].
5. Järvelin MR, Vikeväinen-Tervonen L, Moilanen I, Huttunen NP. Enuresis in seven-year-old children. Acta Paediatr Scand. Jan 1988;77(1):148-53. [Medline].
6. Hellstrom AL, Hanson E, Hansson S, Hjalmas K, Jodal U. Micturition habits and incontinence in 7-year-old Swedish school entrants. Eur J Pediatr. Mar 1990;149(6):434-7. [Medline].
7. Forsythe WI, Redmond A. Enuresis and spontaneous cure rate. Study of 1129 enuretis. Arch Dis Child. Apr 1974;49(4):259-63. [Medline].
8. Himsl KK, Hurwitz RS. Pediatric urinary incontinence. Urol Clin North Am. May 1991;18(2):283-93. [Medline].
9. Dator DP, Hatchett L, Dyro FM, Shefner JM, Bauer SB. Urodynamic dysfunction in walking myelodysplastic children. J Urol. Aug 1992;148(2 Pt 1):362-5. [Medline].
10. Peters CA, Bolkier M, Bauer SB, Hendren WH, Colodny AH, Mandell J, et al. The urodynamic consequences of posterior urethral valves. J Urol. Jul 1990;144(1):122-6. [Medline].
11. Lettgen B, von Gontard A, Olbing H, Heiken-Lowenau C, Gaebel E, Schmitz I. Urge incontinence and voiding postponement in children: somatic and psychosocial factors. Acta Paediatr. 2002;91(9):978-84; discussion 895-6. [Medline].
12. van Gool JD, de Jonge GA. Urge syndrome and urge incontinence. Arch Dis Child. Nov 1989;64(11):1629-34. [Medline].
13. Kuo HC. Effect of botulinum a toxin in the treatment of voiding dysfunction due to detrusor underactivity. Urology. Mar 2003;61(3):550-4. [Medline].
14. Hohenfellner M, Dahms SE, Matzel K, Thüroff JW. Sacral neuromodulation for treatment of lower urinary tract dysfunction. BJU Int. May 2000;85 Suppl 3:10-9; discussion 22-3. [Medline].
15. Klingler HC, Pycha A, Schmidbauer J, Marberger M. Use of peripheral neuromodulation of the S3 region for treatment of detrusor overactivity: a urodynamic-based study. Urology. Nov 1 2000;56(5):766-71. [Medline].
16. Sureshkumar P, Bower W, Craig JC, Knight JF. Treatment of daytime urinary incontinence in children: a systematic review of randomized controlled trials. J Urol. Jul 2003;170(1):196-200; discussion 200. [Medline].
17. Youdim K, Kogan BA. Preliminary study of the safety and efficacy of extended-release oxybutynin in children. Urology. Mar 2002;59(3):428-32. [Medline].
18. Palmer LS, Zebold K, Firlit CF, Kaplan WE. Complications of intravesical oxybutynin chloride therapy in the pediatric myelomeningocele population. J Urol. Feb 1997;157(2):638-40. [Medline].
19. Ferrara P, D'Aleo CM, Tarquini E, Salvatore S, Salvaggio E. Side-effects of oral or intravesical oxybutynin chloride in children with spina bifida. BJU Int. May 2001;87(7):674-8. [Medline].
20. Hjälmås K, Hellström AL, Mogren K, Läckgren G, Stenberg A. The overactive bladder in children: a potential future indication for tolterodine. BJU Int. Apr 2001;87(6):569-74. [Medline].
21. Lopez Pereira P, Miguelez C, Caffarati J, Estornell F, Anguera A. Trospium chloride for the treatment of detrusor instability in children. J Urol. Nov 2003;170(5):1978-81. [Medline].
22. Kjølseth D, Madsen B, Knudsen LM, Nørgaard JP, Djurhuus JC. Biofeedback treatment of children and adults with idiopathic detrusor instability. Scand J Urol Nephrol. Sep 1994;28(3):243-7. [Medline].
23. Curran MJ, Kaefer M, Peters C, Logigian E, Bauer SB. The overactive bladder in childhood: long-term results with conservative management. J Urol. Feb 2000;163(2):574-7. [Medline].
24. Cvitkovic-Kuzmic A, Brkljacic B, Ivankovic D, Grga A. Ultrasound assessment of detrusor muscle thickness in children with non-neuropathic bladder/sphincter dysfunction. Eur Urol. Feb 2002;41(2):214-8; discussion 218-9. [Medline].
25. Franco I. Overactive bladder in children. Part 1: Pathophysiology. J Urol. Sep 2007;178(3 Pt 1):761-8; discussion 768. [Medline].
26. Franco I. Overactive bladder in children. Part 2: Management. J Urol. Sep 2007;178(3 Pt 1):769-74; discussion 774. [Medline].
27. Müller L, Bergström T, Hellström M, Svensson E, Jacobsson B. Standardized ultrasound method for assessing detrusor muscle thickness in children. J Urol. Jul 2000;164(1):134-8. [Medline].

Article Last Updated: Feb 5, 2008