Urodynamics in enuretics I: Reservoir function

Management of nocturnal enuresis - myths and facts

Nocturnal enuresis often causes considerable distress or functional impairment to patient and their parents necessitating a multidisciplinary approach from paediatrician, paediatric nephrologist, urologists and psychiatrist. Mechanisms of monosymptomatic nocturnal enuresis are mainly nocturnal polyuria, bladder overactivity and failure to awaken from sleep in response to bladder sensations. Goal oriented and etiology wise treatment includes simple behavioral intervention, conditioning alarm regimen and pharmacotherapy with desmopressin, imipramine and anticholinergic drugs. Symptoms often recurs requiring change over or combination of different modes of

treatment.

Refractory enuresis in children and adolescents: how can urodynamics affect management and what is the optimum test?

OBJECTIVE

After failure of medical and behavioral therapy in enuresis, the usual next step is to investigate using urodynamics. The aim of this study was to determine the actual benefit and optimal method of urodynamics in the treatment of refractory enuresis.

METHODS

This prospective randomized study included 56 patients: 17 males and 39 females with an age range of 7-16 years. All had tried multiple courses of medical treatment for enuresis for at least 6 months without response. Thirty patients underwent investigation by cystometrogram, uroflowmetry and electromyogram (UFM/EMG), while 26 patients underwent pressure/flow/EMG (P/F/EMG) studies.

RESULTS

Bladder filling abnormalities were found in 25 out of the 56 patients (44.6%) and included low bladder capacity in 39%, hypocompliance in 32%, and detrusor overactivity in 45%. With regard to voiding dysfunction, 70% of the UFM/EMG group had detrusor‒sphincter dyssynergia and 67% of the P/F/EMG group had bladder outlet obstruction.

CONCLUSIONS

Urodynamics can help in cases of refractory enuresis by detecting dysfunctional voiding, which is present in a large percentage of these patients. This can be diagnosed by UFM/EMG, rather than P/F/EMG, as a non-invasive test. UFM alone may be misleading. Alpha adrenergic blockers may be of benefit in treating these patients.

Lower urinary tract symptoms in enuretic and nonenuretic children

PURPOSE

We determined the prevalence of lower urinary tract symptoms in enuretic and nonenuretic children and adolescents in an urban community.

MATERIAL AND METHODS

We performed a cross-sectional survey including 296 children and adolescents in a small urban community. Trained medical students visited all homes and interviewed the parents or guardians. There were no refusals to participate. Results were analyzed using chi-square and McNemar statistics.

RESULTS

The enuresis rate was 10%, including 16.6% and 3.9% in children 5 to 10 years old and adolescents, respectively. The monosymptomatic enuresis rate was only 1.34%. Of those with vs without enuresis lower urinary tract symptoms were present in 86.7% vs 26.8% (p <0.001). In the nonenuretic group lower urinary tract symptoms were associated with nocturia (p = 0.008). The most common daytime urinary symptoms were urgency in 38.2% of cases, holding maneuvers in 30.4% and daytime incontinence in 27.5%. The prevalence rate decreased with age in the nonenuretic group (p = 0.013).

CONCLUSIONS

The prevalence of lower urinary tract symptoms was high. Nonmonosymptomatic enuresis was common and monosymptomatic enuresis was rare in this population based survey. In nonenuretic cases daytime symptoms were associated with nocturia, suggesting decreased bladder capacity with a mature arousal reaction.

Practice parameter for the assessment and treatment of children and adolescents with enuresis

Enuresis is a symptom that is frequently encountered in child psychiatric evaluations. Careful assessment is required to identify specific urologic, developmental, psychosocial, and sleep-related etiologies. For most children with enuresis, however, a specific etiology cannot be determined. Treatment then involves supportive approaches, conditioning with a urine alarm, or medications--imipramine or desmopressin acetate. The psychosocial consequences of the symptom must be recognized and addressed with sensitivity during the evaluation and treatment of enuresis.

Nocturnal enuresis: medical management

Nocturnal enuresis is a problem that affects many children and their families. The etiology seems to be multifactorial and may include a combination of genetic factors,abnormal urodynamics, alterations in vasopressin secretion, sleep factors, psychologic factors, organic disease, and maturational delay. Generally, a complete history and physical examination, with a specific focus on the genitourinary, gastrointestinal, and neurologic systems, is all is that is needed in the evaluation of a patient with enuresis.Currently, the mainstays of medical therapy are DDAVP, imipramine, and oxybutynin. Medications can help to control the symptoms of enuresis, but they generally do not provide a cure; therefore, behavioral therapy is often recommended in conjunction with pharmacotherapy.

THE EFFECT OF ALARM TREATMENT ON THE FUNCTIONAL BLADDER CAPACITY IN CHILDREN WITH MONOSYMPTOMATIC NOCTURNAL ENURESIS

PURPOSE

We studied the characteristics of a group of monosymptomatic nocturnal enuretics successfully treated with the alarm system, with special reference to changes in functional bladder capacity.

MATERIALS AND METHODS

The diaries of 7 girls and 19 boys 7 to 13 years old with severe nocturnal enuresis, small daytime bladder capacity (70% or less of expected capacity for age) and poor or absent response to desmopressin were analyzed. Patients were treated with an alarm until complete dryness was achieved for 21 consecutive nights before ending therapy. Immediately after the treatment they recorded a 1-week followup diary of voiding and fluid intake.

RESULTS

Mean duration of the alarm treatment was 82 days, and there was no change in nocturnal or 24-hour diuresis from baseline to followup. Nocturia developed during the alarm treatment in 48% of the children. The nocturnal diuresis on nocturia nights was significantly higher than on nights without nocturia. Daytime functional bladder capacity increased significantly in children with and without nocturia.

CONCLUSIONS

Treatment with an alarm system increases daytime functional bladder capacity significantly in children with and without nocturia. A higher nocturnal urine production on nocturia nights explains why some children have nocturia and others do not.

Bladder capacity at the time of enuresis

OBJECTIVES

To evaluate bladder capacity at the time of enuresis and compare the daytime capacity of enuretics with that of controls.

METHODS

The functional bladder capacity (FBC), which was the maximal endurable capacity in the daytime, the ordinary bladder capacity (OBC), which was the capacity at ordinary urinary sensation in the daytime, and the enuretic bladder capacity (EBC), which was the capacity at the time of enuresis, were measured in 67 patients with monosymptomatic nocturnal enuresis. The EBC was measured using a diaper and enuresis alarm. The FBC, OBC, and nocturnal bladder capacity, which was the maximal voided volume in the nighttime, were also measured in 67 controls.

RESULTS

The FBC was not significantly different between enuretics and controls. The EBC in enuretics was significantly smaller than the nocturnal bladder capacity in controls. In enuretics, the EBC was significantly smaller than the FBC and was similar to the OBC. In controls, no statistically significant differences were found between the FBC and the nocturnal bladder capacity.

CONCLUSIONS

In enuretics, the bladder capacity during sleep was significantly smaller than the daytime functional capacity. In controls, on the other hand, the bladder capacity during sleep did not differ from the daytime functional capacity. Our understanding of the bladder capacity in enuretics may need to change in view of this result. The inability to hold urine during sleep may be an important cause of nocturnal enuresis.

Primary nocturnal enuresis persistent to adulthood, functional evaluation

INTRODUCTION AND OBJECTIVES

The incidence of nocturnal enuresis (NE) in adults (over 18 years of age) ranges from 0.5 to 2% for most authors. NE is a multifactorial disease. Lack of circadian rhythm of antidiuretic hormone (ADH) is one of the commonly accepted causes, however, disorders affecting bladder function is another important pathophysiologic factor that has not been settled. The target of the present study is to define bladder function in adults having persistent NE.

METHODS

Fifty two adult patients were included. Mean age was 23.6 +/- 6.9 years. All of them had primary NE persistent to adulthood. No treatment was received within 2-7 days prior to the urodynamic examination. All of them had intact neuro-urological examination. Filling (in all patients) and voiding cystometry (in 29 patients) were carried out, using 8 F urodynamic and 8 F rectal catheters. Pressure flow analysis was interpreted using Schafer's nomogram.

RESULTS

Overall mean maximum cystometric capacity was 419.2 +/- 142 ml, mean bladder compliance was 51.3 +/- 39.7 ml/cmH2O. In males (n=25), mean maximum cystometric capacity was 453 +/- 173 ml and compliance was 56 +/- 42 ml/cmH2O, while in females (n=27), mean capacity was 388 +/- 98 ml and compliance was 46.7 +/- 36.7 ml/cmH2O. Twenty patients had detrusor instability (38.5%). Twelve out of 27 (44.4%) females had instability while only 8 out of 25 (32%) males had the same finding. Differences relevant to maximum bladder capacity and compliance between the patients with and without instability were significant (P<0.0001). Mean detrusor opening pressure was 55.3 +/- 25 cmH2O, mean detrusor pressure at maximum flow and maximum detrusor pressure, were 53.5 +/- 21 and 78.9 +/- 35 cmH2O respectively.

CONCLUSIONS

Urodynamic studies in adults with persistent NE reveals a relatively high incidence of instability, normal capacity and compliance. The presence of instability was associated with smaller bladder and poorer compliance and with diurnal urgency. Voiding bladder function in adult enuretics was found to be normal.

Value of increase in bladder capacity in treatment of refractory monosymptomatic nocturnal enuresis in children

OBJECTIVES

To evaluate children with refractory monosymptomatic nocturnal enuresis to determine whether detrusor overactivity (DOA) plays a role in 4 weeks of unsuccessful treatment with retention control training (RCT); whether an increase in bladder capacity can eventually be obtained by RCT plus oxybutynin; and whether the increase in capacity is the primary key to success.

METHODS

Sixty-eight children with refractory monosymptomatic nocturnal enuresis were included. They all had a maximal cystometric capacity less than the age-expected value. RCT was done by water loading and retention to the point of urgency once daily. During training, changes in bladder capacity were evaluated by voiding charts. If after 4 weeks of RCT, less than a 10% increase in bladder capacity was noted, oral oxybutynin was added.

RESULTS

The incidence of DOA was 66%. After 4 weeks of RCT, the bladder capacity increased in 20.6%. Combining RCT with oxybutynin led in the end to normalization of the bladder capacity in 79.4%. Older age and high-pressure DOA negatively influenced the ability to increase the bladder capacity. Fifteen children became completely dry, mainly by converting enuresis to nocturia.

CONCLUSIONS

Unsuccessful RCT is often caused by DOA, especially if a bladder capacity rise of at least 10% cannot be achieved within 4 weeks. If oxybutynin is added to the treatment, normalization of bladder capacity can be obtained in most. This increased bladder capacity cures enuresis only in a minority by sharpening their arousal and provoking nocturia.

Reduction in nocturnal functional bladder capacity is a common factor in the pathogenesis of refractory nocturnal enuresis

OBJECTIVE

To evaluate the diurnal and nocturnal bladder reservoir function in patients with refractory primary nocturnal enuresis (PNE).

PATIENTS AND METHODS

Ninety-five children (68 boys, 27 girls, mean age 9.3 years) with significant PNE (>/=3 wet nights/week) that was refractory to treatment with desmopressin +/- an enuretic alarm were assessed using detailed recording of voiding frequency and urinary volume both day and night, natural filling cystometry during the day and continuous cystometry with simultaneous electroencephalogram monitoring during sleep at night.

RESULTS

Patients could be broadly categorized into two groups. Group A comprised those with normal daytime urodynamics and functional bladder capacity (FBC) on detailed frequency-volume recording, but who developed marked detrusor instability associated with a significant reduction in nocturnal FBC and small-volume voiding only after sleep at night (33 patients, 35%); and group B, those with abnormal daytime urodynamics and with reduced FBC and small-volume voiding both day and night, but who somehow managed to mask their bladder symptoms during the day (62 patients, 65%). There was no evidence of nocturnal polyuria in either group and the ratios of day : night urinary output volumes for type A and type B patients were 1.48 and 1.99, respectively.

CONCLUSION

A reduction in nocturnal FBC, either occurring only after sleep at night in association with the appearance of detrusor instability in patients with normal daytime urodynamics and FBC, or as a manifestation of occult voiding dysfunction or bladder outlet obstruction that affects the bladder reservoir function both day and night, appears to be a common factor and probably the main cause for a mismatch between nocturnal urine output and bladder storage capacity in patients with severe bed-wetting that was refractory to treatment.

Enuresis

The authors do not have all of the data about enuresis, and many children are subject to relapses or failure of treatment. There is no cause for despondency, however. Enuresis is no longer a mystery. Good data exist about the natural history, epidemiology, and etiology of enuresis. In addition, multiple treatment modalities are available to practitioners. This article has sought to review the scientific literature and to relate the authors' experience with enuresis. The authors recommend a treatment program for children with monosymptomatic nocturnal enuresis that includes removal of caffeine from the diet. Enuretic children do not consume enough fluid, and the authors recommend that the daily fluid requirement be divided during the day: 40% in the morning, 40% in the afternoon, and 20% in the evening, with no restriction of fluid. Normalization of small functional bladder capacities may help to cure enuresis and has an effect on the efficacy of other therapies. Treatment of enuretics with antibiotics is effective in children with UTI, bacteriuria, or cystitis cystica. DDAVP has been shown to be effective in the treatment of enuresis, especially in children who have achieved a normal functional bladder capacity. Bladder alarm systems also offer a potential cure of enuresis, are inexpensive, and show a low relapse rate.

Increased delta component in computerized sleep electroencephalographic analysis suggests abnormally deep sleep in primary monosymptomatic nocturnal enuresis

OBJECTIVE

The aim of this study was to investigate sleep and the sleep modulating effect of 1-desamino-8-D-arginine vasopressin (DDAVP) in patients with primary monosymptomatic nocturnal enuresis and controls by means of both conventional polysomnography and computerized electroencephalographic (EEG) power analysis.

MATERIAL AND METHODS

Adolescents or adults with primary monosymptomatic nocturnal enuresis (n = 11, 8 females, 3 males: mean age 23.0 +/- 9.8, range 15-49 years) and normal subjects (n = 10, 7 females, 3 males: mean age 23.2 +/- 5.4, range 14-32 years) were admitted to the sleep laboratory of the University Hospital of Aarhus, Denmark, for the investigation of sleep over four consecutive nights. A fixed day-to-night cycle was maintained. Night-time was defined as 23.00-07.00 h. The 1st and 3rd nights were completed without intervention. Sleep was modulated on the 2nd night by a waterload to induce nocturnal micturition. On the 4th night all subjects received DDAVP spray applied intranasally at bedtime. Sleep was evaluated by manual polysomnography according to the rules of Rechtschaffen and Kales and by computerized EEG power analysis on the 1st, 3rd and 4th nights. EEG power was calculated as total power and as power assigned to specific EEG frequency bands.

RESULTS

Enuretics showed a significant increase in the EEG delta power component during baseline sleep compared with controls, whereas no difference was encountered using a manual sleep score. During recovery sleep on the 3rd night EEG power in the enuretic group was increased in all EEG frequency bands apart from the alpha and sigma bands and associated with a shortened total sleep period. DDAVP was not found to influence sleep to any significant extent.

CONCLUSIONS

EEG power analysis indicates an increased depth of sleep in enuretics inadequately reflected by a conventional polysomnographic technique. No sleep-modulating effect of DDAVP was detected.

Sleep disturbance and bladder dysfunction in enuretic children with treatment failure: fact or fiction?

To document the occurrence of sleep disturbance and bladder dysfunction in enuretic children, 25 children (21 boys, 4 girls, mean age 9.9 years) with monosymptomatic nocturnal enuresis were studied. All children had significant enuretic symptoms (> 4 wet nights per week) which persisted after treatment failure. The investigation protocol included cystometry during the day, simultaneous polysomnographic and cystometric monitoring during the night and recording of diurnal and nocturnal urine output. None of the patients had nocturnal polyuria. According to the presence or absence of sleep disturbance and/or bladder dysfunction, five different patterns could be recognized. These patterns were grouped as having normal and abnormal daytime urodynamics. In conclusion, sleep disturbances and bladder dysfunction are common among enuretic children, especially those who fail to respond to treatment.

Bladder dysfunction in children with refractory monosymptomatic primary nocturnal enuresis

PURPOSE

We studied bladder dysfunction in children with significant primary nocturnal enuresis refractory to treatment.

MATERIALS AND METHODS

We evaluated 33 Chinese boys and 8 girls with a mean age of 10.4 years, who had significant monosymptomatic primary nocturnal enuresis (3 or more wet nights weekly) after desmopressin treatment with or without an enuretic alarm failed. Daytime cystometry, continuous nighttime cystometry and electroencephalography monitoring during sleep, and detailed recording of daytime and nighttime urinary output were performed.

RESULTS

We recognized 5 patterns of bladder dysfunction and its association with sleep-arousal status. Pattern 1 was normal daytime urodynamics with significant bladder instability at night with normal volume voiding precipitated by unstable detrusor contractions in 14 boys (34%). Pattern 2 was normal daytime urodynamics with frequent small volume voiding at night, probably representing latent bladder instability, in 4 boys (10%). Pattern 3 involved abnormal daytime urodynamics with small bladder capacity, a discoordinated daytime voiding pattern and marked nighttime bladder instability associated with poor sleep in 6 boys (15%). Pattern 4 was abnormal daytime urodynamics with an obstructive pattern, and marked daytime and nighttime detrusor hypercontractility (mean maximum detrusor pressure 178 cm. water) in 8 boys (20%). Pattern 5 was abnormal daytime urodynamics with a dysfunctional daytime voiding pattern and frequent small volume nighttime voiding in 8 girls and 1 boy (22%). In all patients functional bladder capacity was smaller than expected for age and the majority had no nocturnal polyuria. Despite underlying bladder dysfunction a 4-week course of 400 microg. desmopressin orally at bedtime still produced a significant response with a greater than 50% decrease in the number of wet nights during treatment in 47% of the patients, although enuretic symptoms immediately relapsed on cessation of therapy in all. Notably cystourethroscopy in 7 of the 8 boys with pattern 4 dysfunction revealed bladder trabeculations and abnormal urethral lesions, including congenital obstructive posterior urethral membranes in 4, Moormann's ring in 2 and irregular scarring at the bulbous urethra in 1.

CONCLUSIONS

Abnormal bladder function, including small functional capacity, instability during sleep and marked detrusor hypercontractility, was common in our enuretic children in whom treatment failed. More importantly, nocturnal enuresis may be the only presenting symptom and there may be a response to desmopressin with a decreased number of wet nights even in cases of significant underlying bladder dysfunction. These findings may have important implications for our management strategy for monosymptomatic primary nocturnal enuresis.

Treatment of nocturnal enuresis with an ultrasound bladder volume controlled alarm device

PURPOSE

Current treatment regimens for nocturnal enuresis are suboptimal. Medications such as desmopressin are efficacious for preventing the enuretic event but they offer little potential for a permanent cure and have side effects. Although the moisture alarm has good potential for a permanent cure, the child is mostly wet during treatment. Furthermore, the moisture alarm requires that the child make the somewhat remote association between the alarm event and a full bladder after the bladder has emptied. In this exploratory study bladder volume alarming, a new approach to treating nocturnal enuresis, was investigated.

MATERIALS AND METHODS

A total of 40 sequential children 6 to 16 years old with nonorganic nocturnal enuresis who had had at least 1 wetting episode weekly for greater than a year were divided into 2 groups. Each child wore a modified PCI 5000 miniature bladder volume measurement instrument during sleep. An alarm sounded when bladder volume reached 80% of the typical daytime voided volume in group 1 and at 80% of the typical enuretic volume in group 2. Group 2 patients also performed daytime bladder retention exercises in regard to instrument measured bladder volume versus a progressing target volume.

RESULTS

In groups 1 and 2 the mean dryness rate before study initiation versus during the study was 32.9 and 9.3 versus 88.7 and 82.1%, respectively. Nighttime bladder capacity increased 69% in group 1 and 78% in group 2, while the cure rate was 55% (mean treatment period 10.5 months) and 60% (mean treatment period 7.2 months), respectively.

CONCLUSIONS

Bladder volume tracking seems to approach the goals of ideal treatment for nocturnal enuresis in that it prevents the enuretic event, appears to facilitate a permanent cure and is noninvasive.

The role of bladder biofeedback in the treatment of children with refractory nocturnal enuresis associated with idiopathic detrusor instability and small bladder capacity

PURPOSE

Not all children with primary nocturnal enuresis, an unstable detrusor and small bladder capacity can be treated successfully with anticholinergics and bladder drill. We report our use of bladder biofeedback in patients who did not respond to 3 months of such treatment.

MATERIALS AND METHODS

A total of 24 patients (median age 10.4 years) were studied. For bladder biofeedback a transurethral catheter was placed and connected with a 3-way connector. The bladder was slowly filled through this catheter and the intravesical pressure could be seen on a vertical tube, which was also connected to the transurethral catheter. The perineal bulbar detrusor inhibiting reflex was used in cases of involuntary bladder contraction. During the day patients retained urine as long as possible and completed a micturition chart.

RESULTS

Of the 24 patients bed-wetting stopped completely in 17 and decreased in 6, and treatment failed in 1. All patients were followed for at least 6 months after treatment. There were 2 cases of recurrence in the group that was cured.

CONCLUSIONS

Intravesical biofeedback can successfully treat patients with refractory primary enuresis associated with unstable detrusor and small bladder capacity.

The role of bladder biofeedback in the treatment of children with refractory nocturnal enuresis associated with idiopathic detrusor instability and small bladder capacity

PURPOSE

Not all children with primary nocturnal enuresis, an unstable detrusor and small bladder capacity can be treated successfully with anticholinergics and bladder drill. We report our use of bladder biofeedback in patients who did not respond to 3 months of such treatment.

MATERIALS AND METHODS

A total of 24 patients (median age 10.4 years) were studied. For bladder biofeedback a transurethral catheter was placed and connected with a 3-way connector. The bladder was slowly filled through this catheter and the intravesical pressure could be seen on a vertical tube, which was also connected to the transurethral catheter. The perineal bulbar detrusor inhibiting reflex was used in cases of involuntary bladder contraction. During the day patients retained urine as long as possible and completed a micturition chart.

RESULTS

Of the 24 patients bed-wetting stopped completely in 17 and decreased in 6, and treatment failed in 1. All patients were followed for at least 6 months after treatment. There were 2 cases of recurrence in the group that was cured.

CONCLUSIONS

Intravesical biofeedback can successfully treat patients with refractory primary enuresis associated with unstable detrusor and small bladder capacity.

Elevated sleep arousal thresholds in enuretic boys: clinical implications

Enuretic children are described as difficult to arouse from sleep. We studied auditory sleep arousal thresholds in enuretic boys and report on the clinical implications of these findings. Fifteen enuretic and 18 control subjects (7-12-year-old males) were studied in a sleep laboratory for four consecutive nights using standard polysomnographic recording techniques. Sleep was undisturbed for the initial two nights and waking thresholds were measured on the following two nights. Enuretic children wet most frequently in the first two-thirds of the night. Arousal attempts were successful 39.7% of the time in controls and only 9.3% of the time in enuretics. In conclusion, enuretic males were more difficult to arouse than age-matched controls. The elevated arousal thresholds may be due to delayed maturation. Treatment programmes that rely on awakening should be aware of these features.

Cure of nocturnal enuresis: why isn't desmopressin very effective?

Prospective controlled studies on the treatment of enuresis with desmopressin (DDAVP) indicate that cure rates (complete dryness) while on therapy are markedly lower than are response rates (decrease in wet nights). In an attempt to explain this discrepancy, we analyzed the etiological mechanisms for enuresis and found evidence that most children are not cured by DDAVP because their nocturnal wetting is not actually caused by the defect which DDAVP therapy aims to cure: low nocturnal vasopressin secretion with high nocturnal urinary output. Our study suggested that an arrest in the normal development of two separate areas of the central nervous system is necessary for enuresis to occur in many patients, yet cure of enuresis occurs if either developmental delay is eliminated. This hypothesis of a dual developmental delay helps to unify many diverse and often seemingly contradictory scientific observations about this condition and to explain why many patients react inconsistently to treatment aimed at a single etiology, yet eventually become dry.

The influence of small functional bladder capacity and other predictors on the response to desmopressin in the management of monosymptomatic nocturnal enuresis

PURPOSE

The relationship of functional bladder capacity as well as other variables to the responsiveness to desmopressin in children with monosymptomatic nocturnal enuresis was investigated.

MATERIALS AND METHODS

A total of 95 children 8 to 14 years old with monosymptomatic nocturnal enuresis (6 or more of 14 nights wet) were evaluated in a double-blind study followed by open label crossover extension using 20 to 40 mcg. desmopressin. Evaluated predictors of response included patient age, gender, race, family history, number of baseline wet nights, urine osmolality parameters and maximum functional bladder capacity (as a percent of predicted bladder capacity based on the formula, patient age + 2 x 30 = cc). Responders to desmopressin were classified as excellent (2 or less of 14 nights wet) or good (50% or greater decrease but more than 2 of 14 nights wet) and nonresponders were defined by a less than 50% decrease in wet nights.

RESULTS

Of the 95 patients 25 (29.5%) achieved an excellent response to desmopressin and 18 (18.9%) had a good response for a cumulative response rate of 45.3%. The remaining 52 patients (54.7%) were nonresponders. There were no significant differences between responders and nonresponders in regard to gender, race, positive family history or baseline urine osmolality parameters. Response to desmopressin was associated with older age, fewer baseline wet nights and larger bladder capacity. Patients with a functional bladder capacity greater than 70% predicted bladder capacity were 2 times more likely to respond to desmopressin.

CONCLUSIONS

The responsiveness of children with nocturnal enuresis to desmopressin is adversely affected by reduced functional bladder capacity. The results of this study have implications regarding the potential use of combination pharmacotherapy with desmopressin and an anticholinergic for enuretic patients who are nonresponsive to single drug therapy.

Primary nocturnal enuresis and desmopressin treatment: do psychosocial factors affect outcome?

Twenty-three patients (5 to 15 years of age) with primary nocturnal enuresis were treated with desmopressin (DDAVP) according to a four-step protocol with weekly reductions of daily doses (1 to 0.25 microgram/kg body weight) thus including aspects of behavior-oriented "bladder retention training". The rate of wet nights was significantly reduced while patients were on medication (p < 0.02), but the sample as a whole returned to baseline levels after medication was stopped. Six subjects (26%) were non-responders. A variety of psychological and psychosocial single factors did not significantly affect the outcome. However, a subgroup of seven patients assessed as "psychologically non-distressed" revealed better results both on medication (p < 0.02; reduction 73%) and off medication (p > or = 0.05; reduction 39%) compared to a "distressed" subgroup (N = 16). Both groups showed significant changes in wet nights over the treatment course (p < 0.02 and p > or = 0.002, respectively). There was no clear-cut relationship between laboratory data (urine volume, osmolality, vasopressin) and outcome in wet nights. Data did not suggest a subgroup of patients with particularly low nocturnal vasopressin (AVP) secretion and, thus, high rates of wet nights. Our results corroborated the finding that DDAVP is an effective substance in reducing wet nights in patients with primary nocturnal enuresis. However, with respect to major reductions and long-term results (off medication), these preliminary findings suggest that "psychological distress" seems to be a very important confounding outcome variable. Thus, careful consideration and assessment of psychological and psychosocial aspects of distress are recommended. Eventually, a combination of DDAVP treatment with counseling and/or psychotherapy may significantly improve results for the majority of patients and families.

Maximal electrical stimulation in children with unstable bladder and nocturnal enuresis and/or daytime incontinence: a controlled study

The aim of this study was to investigate clinical and urodynamic effects of anal MES in children with unstable bladder and micturition problems (nocturnal enuresis and/or daytime incontinence). Seventy-three girls, aged 5 to 17 years, mean age 9.7 years, with cystometrically proved idiopathic detrusor instability and nocturnal enuresis and/or daytime incontinence, were treated by maximal electrical stimulation (MES) for 1 to 2 months. Twenty-one girls, aged 6 to 14 years, mean age 9.3 years, with unstable bladder and micturition problems used only the anal plug without a battery for 1 month and served as the control group. Four and a half months (1-36 months) after the end of treatment, 75% of the stimulated patients were cured or improved by 50% or more. In the control group, 86% of the girls remained unchanged (P < 0.01). One month after the completion of anal MES the average number of monthly nocturnal enuretic episodes fell from 14 to 6.5 (P < 0.001) and the number of daytime incontinence episodes diminished from 3 to 0 (P < 0.001). On an average of 14.5 months after the end of anal MES, enuresis recurred in 20% of cases. Post-MES cystometry showed intensified first desire to void (P < 0.05), as well as an increase in maximum cystometric capacity (P < 0.0001), bladder compliance (P < 0.0001), and volume of the first detrusor contraction (P < 0.01). A statistically significant decline in the number of uninhibited contractions was also noticed (P < 0.001). In the control group, the anal plug did not produce any significant cystometrical changes. Anal MES can be recommended as an effective method for treating nocturnal enuresis and/or daytime incontinence and unstable bladder in children.

Response to desmopressin as a function of urine osmolality in the treatment of monosymptomatic nocturnal enuresis: a double-blind prospective study

To determine if urine osmolality parameters can predict whether children with primary monosymptomatic nocturnal enuresis will respond to desmopressin, we conducted a prospective, double-blind, placebo-controlled study in 96 children 8 to 14 years old. Following a 2-week baseline screening interval patients with at least 6 of 14 net nights were randomized to double-blind regimens of desmopressin or placebo. Urine specimens for osmolality were collected at 6 p.m. and 6 a.m. on 3 consecutive days during the baseline and the 2, 14-day treatment periods. A significantly greater proportion of desmopressin treated children had an excellent (2 or fewer wet nights in 14 days) or good (greater than 50% reduction in wet nights) response compared with placebo treated children (p = 0.004 and p = 0.002 for treatment periods 1 and 2, respectively). Children treated with desmopressin reported a significantly lower number of wet nights than placebo treated children during both treatment periods (p = 0.0258 and p = 0.0136, respectively). Children treated with desmopressin had a significantly higher 6 a.m. urine osmolality during both treatment periods and a higher 6 a.m.-to-6 p.m. osmolality ratio (p = 0.004) in the first treatment period compared with the placebo group. Within the desmopressin treatment group clinical responders had a higher 6 a.m. urine osmolality and 6 a.m.-to-6 p.m. urine osmolality ratio than nonresponders during both treatment periods but these differences did not achieve statistical significance. In conclusion, treatment with desmopressin is associated with a significant decrease in the number of wet nights, and a significant increase in nocturnal urine osmolality and nocturnal/diurnal urine osmolality ratios. However, clinical response was not predictable based on baseline or treatment osmolality parameters.

Nocturnal enuresis

Nocturnal enuresis is common. Although its aetiology remains unclear recent evidence increasingly supports the lack of a normal nocturnal increase in ADH leading to nocturnal polyuria exceeding functional bladder capacity. Sleep patterns are probably normal although an arousal disorder might be a factor. Treatment should follow careful evaluation to determine if one is dealing with 'uncomplicated' or 'complicated' enuresis. Complicated enuresis requires further investigation. 'Uncomplicated enuresis' always requires reassurance and patient and parent education. Resource centres such as ERIC can provide information and advice. Active treatment should be tailored to the patients age, motivation and parental wishes. Behavioural modification techniques yield the highest long-term cure rate but require the most commitment and are rarely successful before the age of 7-8 years. Pharmacotherapy has been revolutionized by DDAVP which gives a response rate of up to 70% relatively free from side-effects but at the price of a high relapse rate after medication. Imipramine is less expensive than DDAVP but may be fatal in overdose. Anticholinergics should be reserved for those patients with significant diurnal symptoms or those who fail first-line pharmacotherapy. Overall patients and parents should be reassured by the high spontaneous cure rate.

Enuresis in an adult female with obstructive sleep apnea

Adult onset enuresis accompanied by obstructive sleep apnea has been reported rarely. A female patient was referred to our clinic with complaints of of a 15-year history of loud snoring and sleep apnea as well as enuresis, which was treated successfully with imipramine and acetazolamide. The mechanism of enuresis and its relationship to upper airway obstruction are reviewed here with reference to the findings of polysomnography and sleep cystometry.

Functional bladder capacity and calcium-creatinine quota in enuretic patients, former enuretic and non enuretic controls

Functional bladder capacity and Urine Calcium/creatinine quota were investigated in 13 patients with primary nocturnal enuresis, 15 former enuretic patients and 15 controls. The functional bladder capacity was measured in ml and determined by a standardised daytime oral water load test which was performed in the homes. There was an age-related increase in bladder capacity in all three groups. There was no significant difference between any of the groups in bladder capacity. There wasn't any elevation of the calcium/creatinine quota in the enuretic patients, but former enuretic children had an increased calcium creatinine quota in the morning urine. Calcium/creatinine quota was also studied in 15 adult former enuretics and 15 adult control individuals without finding any difference between the groups. This investigation suggests that the functional bladder capacity is not a major pathogenic factor in primary nocturnal enuresis.

Nocturnal enuresis: change of nocturnal voiding pattern during alarm treatment

In a prospective clinical study of the outcome of alarm treatment in nocturnal enuretics, 60 children were included: 40 boys and 20 girls, mean age 8.2 years (range 5.1-14.4). All were treated with enuresis alarms and had 2 or more enuretic events during the initial 14 days of treatment. None had diurnal enuresis. In each child, the enuretic and voluntary voiding frequencies during the initial 14 and last 14 days of treatment were compared. We found that 43 children had a 75% reduction or more of the enuretic events. 28 children substituted the former enuretic events by sleep, 15 changed the enuresis by voluntary voidings. Only 17 children had no effect of the alarm treatment. No parameters were found to predict the outcome. In conclusion, the outcome of successful alarm treatment occurs in two distinct forms. Either the child is left asleep without wetting his bed; or the child wakes up spontaneously from sleep and goes to the bathroom.

Dysfunctional voiding syndromes and vesicoureteral reflux

Micturition disorders simulating neurogenic bladder disease have been loosely termed "dysfunctional voiding". No underlying neuropathy can be found. A variety of voiding disturbances have been identified since the early 1970s, each with its own characteristics and clinical relevance. We have classified voiding dysfunctions into mild, moderate and severe, according to their potential impact on the upper tracts. Bladder instability, the Hinman syndrome and the Ochoa syndrome are the only dysfunctional voiding syndromes that are associated with reflux or ureterovesical obstruction. Each syndrome is briefly described.

A new technique for dynamic analysis of bladder compliance

We propose an alternative method of measuring compliance that takes into account the multiple phases of bladder filling. We describe our new technique, dynamic compliance analysis, and evaluate its clinical applicability. To perform the analysis we digitized a cystometrogram curve at a sampling rate of 2 samples per second using an MS-DOS computer system. A program designed to retrieve the stored data was used to analyze the subtracted bladder pressure. The result yielded a value of compliance every half second that was then plotted on an x-y graph, with instantaneous compliance as the dependent variable and per cent of total volume infused as the independent variable. To determine the clinical applicability of this technique we chose 63 curves from clinically normal patients. The results of the dynamic compliance analyses were predictable. The dynamic compliance values for the normal group had a minimum that was always greater than 10 ml./cm. water throughout the tonus limb (phase 2) of the cystometrogram. We conclude that dynamic compliance analysis yields more information about bladder response during filling, similar to the stress-strain curve used in the study of solid mechanics.

Evaluation of the enuretic child

Nocturnal enuresis is a symptom of environmental, physical, and psychosocial factors. In addition to a physical examination, the initial workup of the enuretic child should include a careful voiding, psychosocial, and family history. Studies have shown that the parents of enuretic children often have a history of enuresis. An increased incidence of enuresis has also been demonstrated in children from large families and lower socioeconomic groups. Daytime voiding symptoms (e.g., frequency, urgency, or enuresis) suggest the possibility of underlying voiding dysfunction. A complete urinalysis and urine culture also should be performed to exclude urinary infection and certain metabolic or nephrologic disorders. Finally, it is important that the treating physician understand the attitudes of both the child and the family concerning enuresis. Parents who feel that the child is at fault need to be educated and reassured. A careful, complete evaluation will allow the physician to tailor treatment to the individual child and family.

Effect of time interval and overdistension on repeated urodynamic studies

Repeated urodynamic testing of the lower urinary tract is often needed both clinically and experimentally. The objective of this study is to find out the time interval needed if repeated urodynamic tests are required even if overdistension occurs initially. Three hundred forty urodynamic studies were performed using five female rhesus monkeys (Macaca mulatta). Two groups of experiments (with or without bladder overdistension) were performed at the following time intervals: immediate, 15, 30 and 45 minutes after the initial urodynamic study. All urodynamic parameters (pressure, capacity, compliance and detrusor strength) were reproducible after a 30-minute waiting period. In case of overdistension, a 45-minute period is required.

Night studies for primary diurnal and nocturnal enuresis and preliminary results of the "clam" ileocystoplasty

Modified conventional urodynamic apparatus was used to provide overnight monitoring of bladder and rectal pressure. A group of 26 patients with primary diurnal and nocturnal enuresis underwent both daytime rapid fill cystometry and overnight natural fill cystometry. The overnight study was effective in detecting detrusor instability in 10 patients deemed normal on rapid fill cystometry; 6 of these have now undergone clam ileocystoplasty and 5 are dry; 3 are awaiting this procedure. The clam remains very effective in the management of patients with resistant nocturnal and diurnal enuresis if careful selection is adopted. Overnight cystometry has proved to be an invaluable adjunct to the investigation of patients with primary diurnal and nocturnal enuresis previously felt to be urodynamically normal.

Sleep cystometries in children with nocturnal enuresis

A combined analysis was done of sleep and bladder filling during sleep. Cystometry did not specifically affect sleep, since most of the cystometry studies in cases of enuresis did not lead to sleep stage changes on electroencephalography. Bladder instability was not accompanied by lighter sleep. Increasing patient age did not appear to have any influence on sleep or bladder behavior. We conclude that it is possible to provoke enuresis at any sleep stage and that sleep is unaffected by bladder filling in enuretic patients.