The Role of Non-invasive Testing in Evaluation and Diagnosis of Pediatric Lower Urinary Tract Dysfunction.

PURPOSE OF REVIEW: The symptoms of lower urinary tract dysfunction (LUTD) including urinary incontinence, frequency, and urgency are among the most common reasons children are referred to pediatric urologists. Despite this, the workup for LUTD is often time consuming and a source of frustration for patients, parents, and clinicians alike. In the current review, we summarize the important role non-invasive testing plays in the diagnosis and management of children with LUTD and to show how use of these tests can help avoid the need for more invasive testing in the majority of children. RECENT FINDINGS: Non-invasive tests such urine studies, uroflowmetry ± simultaneous electromyography, assessment of post-void residual, renal/bladder ultrasound, and pelvic ultrasound when used appropriately can provide valuable information to facilitate decision making during the evaluation of children with LUTD. While these tests should be employed prior to more invasive testing such as urodynamic studies, they can often act as a surrogate for the more invasive tests. Non-invasive tests can help us in our goal of improving diagnostic ability to better classify the child's LUTD into an actual condition which allows targeted treatment in the hope of better outcomes and more satisfied patients and families.

Short pelvic floor electromyographic lag time: a novel noninvasive approach to document detrusor overactivity in children with lower urinary tract symptoms.

PURPOSE: Noninvasive uroflow with simultaneous electromyography can measure electromyographic lag time, ie the interval between the start of pelvic floor relaxation and the start of urine flow (normally 2 to 6 seconds). Intuitively one would expect that in patients experiencing urgency secondary to detrusor overactivity the lag time would be short or even a negative value. We studied whether short electromyographic lag time on uroflow with electromyography actually correlates with documented detrusor overactivity on urodynamics. MATERIALS AND METHODS: We reviewed 2 separate and distinct cohorts of 50 neurologically and anatomically normal children with persistent lower urinary tract symptoms who were evaluated by uroflow with simultaneous electromyography and videourodynamics. Group 1 consisted of 30 boys and 20 girls (mean age 7.8 years, range 4 to 19) selected based on electromyographic lag time of 0 seconds or less on screening uroflow with electromyography who subsequently underwent videourodynamics. Group 2 consisted of 14 boys and 36 girls (median age 8.4 years, range 5 to 18) selected based on the presence of detrusor overactivity on videourodynamics whose screening uroflow with electromyography was then reviewed. Correlations between short electromyographic lag time and videourodynamically proved detrusor overactivity were analyzed. RESULTS: For group 1 urodynamics confirmed the presence of detrusor overactivity in all patients with an electromyographic lag time of 0 seconds or less. For group 2 mean ± SD electromyographic lag time was 0.1 ± 1.7 seconds, and 35 patients (70%) with urodynamically proved detrusor overactivity had a lag time of 0 seconds or less. CONCLUSIONS: In patients with lower urinary tract symptoms an electromyographic lag time of 0 seconds or less is 100% predictive of detrusor overactivity. This short electromyographic lag time has 100% specificity and 70% sensitivity for diagnosing detrusor overactivity (88% if less than 2 seconds). Thus, diagnosing the presence or absence of detrusor overactivity in most children with lower urinary tract symptoms and a quiet pelvic floor during voiding can be done reliably via uroflow with simultaneous electromyography.

Dysfunctional elimination syndromes--how closely linked are constipation and encopresis with specific lower urinary tract conditions?

PURPOSE: It is recognized that there is a strong association between bladder and bowel dysfunction. We determined the association of constipation and/or encopresis with specific lower urinary tract conditions. MATERIALS AND METHODS: We reviewed our database of children with lower urinary tract dysfunction and divided cases into 3 categories of bowel dysfunction (constipation, encopresis and constipation plus encopresis) and 4 lower urinary tract conditions (dysfunctional voiding, idiopathic detrusor overactivity disorder, detrusor underutilization disorder and primary bladder neck dysfunction). Associations between bowel dysfunction types and each lower urinary tract condition were determined. RESULTS: Of 163 males and 205 females with a mean age of 8.5 years constipation was the most common bowel dysfunction (27%). Although encopresis is generally thought to reflect underlying constipation, only half of children with encopresis in this series had constipation. Dysfunctional voiding was associated with the highest incidence of bowel dysfunction. All but 1 patient with encopresis had associated urgency and detrusor overactivity, and the encopresis resolved in 75% of patients after initiation of anticholinergic therapy. Constipation was significantly more common in girls (27%) than in boys (11%, p <0.01), while encopresis was more common in boys (9%) than in girls (3%, p = 0.02), likely reflecting the higher incidence of dysfunctional voiding in girls and idiopathic detrusor overactivity disorder in boys. CONCLUSIONS: Active bowel dysfunction was seen in half of the children with a lower urinary tract condition. Constipation was more common in patients with dysfunctional voiding, while encopresis was significantly increased in those with idiopathic detrusor overactivity disorder and in those with dysfunctional voiding, severe urgency and detrusor overactivity. Anticholinergics, despite their constipating effect, given for treatment of detrusor overactivity resolved encopresis in most children with this bowel dysfunction.

Prevalence of urinary tract infection and vesicoureteral reflux in children with lower urinary tract dysfunction.

PURPOSE: Lower urinary tract dysfunction is a common pediatric urological problem that is often associated with urinary tract infection. We determined the prevalence of a urinary tract infection history in children with lower urinary tract dysfunction and its association, if any, with gender, bowel dysfunction, vesicoureteral reflux and specific lower urinary tract conditions. MATERIALS AND METHODS: We retrospectively reviewed the charts of children diagnosed with and treated for lower urinary tract dysfunction, noting a history of urinary tract infection with or without fever, gender, bowel dysfunction and vesicoureteral reflux in association with specific lower urinary tract conditions. RESULTS: Of the 257 boys and 366 girls with a mean age of 9.1 years 207 (33%) had a urinary tract infection history, including 88 with at least 1 febrile infection. A total of 64 patients underwent voiding cystourethrogram/videourodynamics, which revealed reflux in 44 (69%). In 119 of the 207 patients all infections were afebrile and 18 underwent voiding cystourethrogram/videourodynamics, which revealed reflux in 5 (28%). A urinary tract infection history was noted in 53% of girls but only 5% of boys (p <0.001). Patients with detrusor underutilization disorder were statistically more likely to present with an infection history than patients with idiopathic detrusor overactivity disorder or primary bladder neck dysfunction (each p <0.01). CONCLUSIONS: Females with lower urinary tract dysfunction have a much higher urinary tract infection incidence than males. This association was most often noted for lower urinary tract conditions in which urinary stasis occurs, including detrusor underutilization disorder and dysfunctional voiding. Reflux was found in most girls with a history of febrile infections. Since reflux was identified in more than a quarter of girls with only afebrile infections who were evaluated for reflux, it may be reasonable to perform voiding cystourethrogram or videourodynamics in some of them to identify reflux.

Outcomes of targeted treatment for vesicoureteral reflux in children with nonneurogenic lower urinary tract dysfunction.

PURPOSE: There is a known association between nonneurogenic lower urinary tract conditions and vesicoureteral reflux. Whether reflux is secondary to the lower urinary tract condition or coincidental is controversial. We determined the rate of reflux resolution in patients with lower urinary tract dysfunction using targeted treatment for the underlying condition. MATERIALS AND METHODS: Patients diagnosed and treated for a lower urinary tract condition who had concomitant vesicoureteral reflux at or near the time of diagnosis were included. Patients underwent targeted treatment and antibiotic prophylaxis, and reflux was monitored with voiding cystourethrography or videourodynamics. RESULTS: Vesicoureteral reflux was identified in 58 ureters in 36 females and 5 males with a mean age of 6.2 years. After a mean of 3.1 years of treatment reflux resolved with targeted treatment in 26 of 58 ureters (45%). All of these patients had a history of urinary tract infections before starting targeted treatment. Resolution rates of vesicoureteral reflux were similar for all reflux grades. Resolution or significant improvement of reflux was greater in the ureters of patients with dysfunctional voiding (70%) compared to those with idiopathic detrusor overactivity disorder (38%) or detrusor underutilization (40%). CONCLUSIONS: Vesicoureteral reflux associated with lower urinary tract conditions resolved with targeted treatment and antibiotic prophylaxis in 45% of ureters. Unlike the resolution rates reported in patients with reflux without a coexisting lower urinary tract condition, we found that there were no differences in resolution rates among grades I to V reflux in patients with lower urinary tract conditions. Patients with dysfunctional voiding had the most improvement and greatest resolution of reflux. Additionally grade V reflux resolved in some patients.

Can staccato and interrupted/fractionated uroflow patterns alone correctly identify the underlying lower urinary tract condition?

PURPOSE: Worldwide, uroflowmetry without simultaneous electromyography is often the only testing performed during the initial assessment of children with lower urinary tract symptoms. Various alterations in uroflow pattern are thought to indicate particular types of lower urinary tract conditions, specifically staccato uroflow indicating dysfunctional voiding and intermittent/fractionated uroflow indicating detrusor underactivity. We determined how reliable uroflow pattern alone is as a surrogate for simultaneously measured pelvic floor electromyography activity during voiding, and how well staccato and interrupted uroflow actually correlate with the diagnoses they are presumed to represent. MATERIALS AND METHODS: We reviewed uroflow/electromyography studies performed during the initial evaluation of 388 consecutive neurologically and anatomically normal patients with persistent lower urinary tract symptoms. We identified those with staccato, interrupted/fractionated and mixed uroflow based on current International Children's Continence Society guidelines. RESULTS: A total of 69 girls (58.5%) and 49 boys (41.5%) met inclusion criteria. Staccato uroflow was noted in 60 patients, interrupted/fractionated uroflow in 28 and a combination in 30. An active electromyography during voiding confirmed the diagnosis of dysfunctional voiding in 33.3% of patients with staccato, 46.4% with interrupted/fractionated and 50% with mixed uroflow patterns. CONCLUSIONS: Diagnoses based on uroflow pattern appearance without simultaneous electromyography to support them can be misleading, and reliance on uroflow pattern alone can lead to overdiagnoses of dysfunctional voiding and detrusor underactivity. When assessing patients with uroflow, an accompanying simultaneous pelvic floor electromyography is of utmost importance for improving diagnostic accuracy and thereby allowing for the most appropriate therapy.

Simplifying the diagnosis of 4 common voiding conditions using uroflow/electromyography, electromyography lag time and voiding history.

PURPOSE: Noninvasive uroflowmetry with simultaneous electromyography is useful to triage cases of lower urinary tract symptoms into 4 urodynamically defined conditions, especially when incorporating short and long electromyography lag times in the analysis. We determined the prevalence of these 4 conditions at a single referral institution and the usefulness of uroflowmetry with simultaneous electromyography and electromyography lag time to confirm the diagnosis, guide treatment and monitor response. MATERIALS AND METHODS: We retrospectively reviewed the records of 100 consecutive normal children who presented with persistent lower urinary tract symptoms, underwent uroflowmetry with electromyography as part of the initial evaluation and were diagnosed with 1 of 4 conditions based on certain uroflowmetry/electromyography features. The conditions included 1) dysfunctional voiding--active pelvic floor electromyography during voiding with or without staccato flow, 2a) idiopathic detrusor overactivity disorder-A--a quiet pelvic floor during voiding and shortened lag time (less than 2 seconds), 2b) idiopathic detrusor overactivity disorder-B--a quiet pelvic floor with a normal lag time, 3) detrusor underutilization disorder--volitionally deferred voiding with expanded bladder capacity but a quiet pelvic floor, and 4) primary bladder neck dysfunction--prolonged lag time (greater than 6 seconds) and a depressed, right shifted uroflowmetry curve with a quiet pelvic floor during voiding. Treatment was tailored to the underlying condition in each patient. RESULTS: The group consisted of 50 males and 50 females with a mean age of 8 years (range 3 to 18). Dysfunctional voiding was more common in females (p <0.05) while idiopathic detrusor overactivity disorder-B and primary bladder neck dysfunction were more common in males (p <0.01). With treatment uroflowmetry parameters normalized for all types. Electromyography lag time increased in idiopathic detrusor overactivity disorder-A cases and decreased in primary bladder neck dysfunction cases. CONCLUSIONS: Noninvasive uroflowmetry with simultaneous electromyography offers an excellent alternative to invasive urodynamics to diagnose 4 urodynamically defined conditions. It identifies the most appropriate therapy for the specific condition and objectively monitors the treatment response.

Nonneurogenic voiding disorders in children and adolescents: clinical and videourodynamic findings in 4 specific conditions.

PURPOSE: We determined if there were any unique findings regarding specific clinical manifestations and videourodynamics among our patients with nonneurogenic voiding disorders. MATERIALS AND METHODS: A cohort of 237 normal children with lower urinary tract symptoms were evaluated by videourodynamics and uroflow/electromyogram, and divided into 4 groups based on the specific urodynamic findings 1) dysfunctional voiding (active electromyogram during voiding with or without detrusor overactivity), 2) idiopathic detrusor overactivity disorder (detrusor overactivity on urodynamics but quiet electromyogram during voiding), 3) detrusor underutilization disorder (willful infrequent but otherwise normal voiding) and 4) primary bladder neck dysfunction. Association of lower urinary tract symptoms, urinary tract infection, vesicoureteral reflux and abnormal urodynamic parameters within each condition was compared. RESULTS: The only strong correlation between a particular symptom and a specific condition was between hesitancy and primary bladder neck dysfunction. Urgency was reported to some degree with all 4 conditions. The most common abnormal urodynamic finding was detrusor overactivity, which was seen in 91% of patients with dysfunctional voiding. The highest detrusor pressures were seen in dysfunctional voiding during voiding and in idiopathic detrusor overactivity disorder during detrusor overactivity. Vesicoureteral reflux was seen in a third of children with dysfunctional voiding or idiopathic detrusor overactivity disorder, in all 8 boys with a history of urinary tract infection and in 51% of patients with febrile or recurrent urinary tract infections with lower urinary tract symptoms when not infected. Bilateral vesicoureteral reflux and bowel dysfunction were most common in dysfunctional voiding. CONCLUSIONS: On objective urodynamic assessment pediatric nonneurogenic voiding dysfunction can essentially be divided into 4 specific conditions. These conditions have distinct urodynamic features that distinguish them from each other, as opposed to their clinical features (particularly lower urinary tract symptoms), which frequently overlap and are not as defining as they are often presumed to be.

Primary bladder neck dysfunction in children and adolescents III: results of long-term alpha-blocker therapy.

PURPOSE: Primary bladder neck dysfunction is a nonneurogenic voiding disorder frequently overlooked in pediatrics. The diagnosis classically is made by videourodynamics but can also be made with noninvasive uroflow studies with pelvic floor electromyography. We report our long-term results using alpha-blocker therapy in patients with primary bladder neck dysfunction. MATERIALS AND METHODS: We reviewed 51 neurologically normal children (mean age 11.6 years, range 3.5 to 17.8) meeting criteria for primary bladder neck dysfunction who underwent alpha-blocker therapy for at least 1 year. All patients were symptomatic with abnormal flow parameters and an electromyogram lag time of 6 seconds or more on initial uroflow/electromyography. Pretreatment and on-treatment uroflow/electromyogram studies were performed in all patients. Average and maximum uroflow rates, electromyogram lag times and post-void residual volumes were compared. RESULTS: After a mean followup of 46.2 months (range 12 to 124) mean average and maximum uroflow rates improved from 7.0 to 12.4 cc per second and from 12.4 to 20.3 cc per second, respectively, while mean electromyogram lag time decreased from 30.8 to 5.8 seconds (all p <0.01). Of the patients 85% reported subjective symptomatic relief. A total of 15 patients (29%) stopped alpha-blocker therapy for various reasons, none related to side effects. Repeat off-treatment uroflow/electromyogram studies showed that measured parameters reverted to pretreatment values (all p <0.05). Eight of these 15 patients eventually resumed alpha-blocker therapy, while only 3 remained asymptomatic off of the alpha-blocker. CONCLUSIONS: alpha-Blocker therapy continues to benefit children with primary bladder neck dysfunction even after 3 years of treatment. Few patients can come off of alpha-blocker therapy without returning to their pretreatment state, suggesting the condition is likely chronic in most patients.

Nonneurogenic voiding disorders: what's new?

PURPOSE OF REVIEW: Increased interest in pediatric nonneurogenic voiding disorders (NNVDs), urodynamic testing and therapeutic options make this a timely topic for review. RECENT FINDINGS: The major themes covered this year included diagnosis of NNVD by symptomatology and relationship to subsequent urodynamic findings and treatment outcomes; effect of bladder volumes and overdistention, test position, catheter size, catheter in or out during voiding and sex on flow rate, flow pattern, voiding pressures, presence of overactivity and interpretation of findings on both urodynamic studies and uroflow testing; associations between bowel disorders (constipation and encopresis) and NNVD, associations between behavioral disorders and bowel disorders as reflected by treatment response and effect on behavior; efficacy studies on symptom-directed therapies in NNVD, comparison of different biofeedback programs for treating dysfunctional voiding, Botox injections for overactive bladder and an adult anticholinergic for overactive bladder that underwent testing in children; enuresis topics included anticholinergics for treating monosyptomatic enuresis refractory to desmopressin, prevalence of enuresis when screening large numbers of healthy school-age children and its association with certain family characteristics and other bowel and bladder complaints and an update on the association of fluctuation of vasopressin and nightly urine output and its role in patient selection for desmopressin therapy. SUMMARY: While some studies simply validated the past work of others, there were several that dispelled beliefs by demonstrating the inaccuracy of predicting voiding disorders on the basis of uroflow alone or the minimal effect of catheter and test position on urodynamic results; behavior disorders require special care but are not an impediment to successful treatment. Newer therapies, including Botox injections and new or broadened indications for existing anticholinergics, in treating the overactive bladder in children need closer scrutiny.

Overactive bladder (OAB): A symptom in search of a disease - Its relationship to specific lower urinary tract symptoms and conditions.

BACKGROUND: The ICCS defines OAB by the subjective symptom of urgency; detrusor overactivity (DO) is only implied. While no other symptom is required, OAB can also be associated with urinary frequency, decreased functional bladder capacity, and incontinence. OBJECTIVE: We sought to determine how often these associated findings occur in OAB and what if any uroflow/EMG-defined conditions are found to be associated with it. METHODS: The charts of 548 children (231M, 318F; mean age 9.0 years, range 3-20) who presented sequentially with urgency (OAB), over a period of 2 years, were reviewed paying particular attention to whether or not there was a history of frequency and/or daytime incontinence in addition to the urgency. All patients had been previously diagnosed with one of the following four lower urinary tract (LUT) conditions based on specific uroflow/EMG findings: 1. dysfunctional voiding (DV; active pelvic floor EMG during voiding); 2. idiopathic detrusor overactivity disorder (IDOD; OAB with a short EMG lag time (<2 s), and quiet pelvic floor EMG during voiding); 3. detrusor underutilization disorder (DUD; willful infrequent voiding with %EBC >125%, quiet EMG during voiding); and 4. primary bladder neck dysfunction (PBND; prolonged EMG lag time (>6 s), quiet EMG during voiding, and depressed uroflow curve). Mean %EBC was compared between patients with urgency alone and those with urgency plus other symptoms. Any association with gender was analyzed. RESULTS: Urgency was accompanied by either frequency or daytime incontinence in 91% of the children (summary Table). Daytime incontinence was reported in 398 (72.6%) and frequency in 268 (48.9%). Mean %EBC was 80.9. Females were more likely to report daytime incontinence (76.7% vs. 66.7%, p = 0.02) and frequency was found more often in males (63.6% vs. 38.1%, p < 0.001). %EBC was less in males (70.0 vs. 88.8, p < 0.001). The majority of patients with urgency were diagnosed with IDOD (62%), while 15% had DV, 5% PBND, 3% DUD, and in 15%, the uroflow/EMG was not diagnostic. CONCLUSIONS: %EBC was usually normal or mildly increased in OAB when urgency is the only symptom but significantly decreases with each additional LUTS. OAB is more common in girls and they tend to have a lower incidence of frequency, more incontinence, and >%EBC than boys. Because urgency in an anatomically and neurologically normal child is the only required criterion for diagnosing OAB, it must be realized that OAB can be associated with any of a number of objectively defined LUT conditions. Thus OAB appears to be a symptom, not a condition, that is often associated with other symptoms.

Can children with either overactive bladder or dysfunctional voiding transition from one into the other: Are both part of a single entity?

BACKGROUND: In 1998 it was postulated by the ICCS that urge syndrome, later termed overactive bladder (OAB), and dysfunctional voiding (DV) might not be separate entities and instead represent transitional stages between each other, and that DV may be the evolutionary end product of OAB. The aim of this study was to determine not only if OAB sometimes transitions into DV but also if the reverse occurs, and, if so, might they indeed be parts of one entity. MATERIALS AND METHODS: To create an objective study of these two conditions, specific "qualifiers" supporting the diagnosis of each condition were introduced: 1) DV included the qualifier of an active EMG during voiding on two studies; 2) OAB included the qualifiers of a short lag time (<2 s) as a surrogate for detrusor overactivity (DO) and a quiet EMG during voiding. Two separate cohorts (one for DV and one for OAB) of 77 consecutive patients each were reviewed. All DV patients were treated with biofeedback and some with antimuscarinics. All OAB patients were treated with antimuscarinics. Both cohorts also received standard therapy and bowel management when indicated. All patients had multiple uroflow/EMG evaluations before and during therapy and were followed for a minimum of 6 months. RESULTS: Mean follow-up was 17.5 months and median age at diagnosis was 6.6 years for DV and 6.4 years for OAB. Of the OAB children none transitioned into DV, although two demonstrated transient DV-like EMG activity on interval testing that did not require biofeedback. Of DV children, following the initiation of biofeedback therapy, the EMG became quiet on follow-up uroflow/EMG after a mean of 9.3 months in 70 of 77 (91%). With EMG quieting, however, a short EMG lag time suggesting DO became apparent in those children with persistent irritative symptoms. This short lag time became apparent in 25 of 31 (81%) children treated with biofeedback alone versus only 8 of 39 (21%) on biofeedback plus antimuscarinics. CONCLUSION: OAB with qualifiers and DV are two distinct LUT conditions and children do not appear to transition from the one to the other. While some children with DV did demonstrate a short lag time during follow-up, this is because once the EMG quieted in response to biofeedback, it improved our ability to document the already existing DO secondary to their previous DV. A dysfunctional voiding sequence with the postulated initial step being the transition of OAB into DV does not seem to be likely as the age at initial diagnosis was similar in both groups.