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

Impaired selective attention in patients with severe primary monosymptomatic nocturnal enuresis: An event-related potential study

Objectives

Primary monosymptomatic nocturnal enuresis (PMNE) is a very common problem in school age children. It is thought that PMNE represents a maturational lag in the central nervous system of those children. We did this case control study to assess the selective attention and resource allocation in those children using the P300 wave of the Event-Related Potentials (ERPs) and its relation to disease severity.

Methods

Forty four patients with PMNE and twenty three healthy controls were included in this study. Patients were diagnosed according to the criteria of international children's continence society and were classified into two groups; patients with frequent wetting (≥4 episodes/week), and patients with infrequent wetting (<4 episodes/week). ERPs were recorded at Fz, Cz, and Pz locations using odd-ball paradigm. N200 and P300 peak latencies (ms), and N200/P300 peak to peak amplitudes (µV) were measured.

Results

We found significant increase of P300 and N200/P300 interpeak latencies, and significant decrease of P300 amplitudes in frequent wetting group "severe" PMNE compared to healthy controls and infrequent wetting group.

Conclusion

Abnormal selective attention and resource allocation were found in patients with severe PMNE. Measures to improve selective attention might be helpful in treatment of patients with severe PMNE.

Significance

Impaired selective attention might play a role in pathogenesis of severe PMNE and the need for the various measures to improve selective attention may be further studied as a therapeutic tool for patients with severe PMNE.

Pediatric Pharmacology of Desmopressin in Children with Enuresis: A Comprehensive Review

Desmopressin is a synthetic analogue of the natural antidiuretic hormone arginine vasopressin. Over the years, it has been clinically used to manage nocturnal polyuria in children with enuresis. Various pharmaceutical formulations of desmopressin have been commercialized for this indication-nasal spray, nasal drops, oral tablet and oral lyophilizate. Despite the fact that desmopressin is a frequently prescribed drug in children, its use and posology is based on limited pediatric data. This review provides an overview of the current pediatric pharmacological data related to the different desmopressin formulations, including their pharmacokinetics, pharmacodynamics and adverse events. Regarding the pharmacokinetics, a profound food effect on the oral bioavailability was demonstrated as well as different plasma concentration-time profiles (double absorption peak) of the desmopressin lyophilizate between adults and children. Literature about maturational differences in distribution, metabolism and excretion of desmopressin is rather limited. Regarding the pharmacodynamics, formulation/dose/food effect and predictors of response were evaluated. The lyophilizate is the preferred formulation, but the claimed bioequivalence in adults (200 µg tablet and 120 µg lyophilizate), could not be readily extrapolated to children. Prescribing the standard flat-dose regimen to the entire pediatric population might be insufficient to attain response to desmopressin treatment, whereby dosing schemes based on age and weight were proposed. Moreover, response to desmopressin is variable, whereby complete-, partial- and non-responders are reported. Different reasons were enumerated that might explain the difference in response rate to desmopressin observed: different pathophysiological mechanisms, bladder capacity and other predictive factors (i.e. breast feeding, familial history, compliance, sex, etc.). Also, the relapse rate of desmopressin treatment was high, rendering it necessary to use a pragmatic approach for the treatment of enuresis, whereby careful consideration of the position of desmopressin within this treatment is required. Regarding the safety of the different desmopressin formulations, the use of desmopressin was generally considered safe, but additional measures should be taken to prevent severe hyponatremia. To conclude the review, to date, major knowledge gaps in pediatric pharmacological aspects of the different desmopressin formulations still remain. Additional information should be collected about the clinical relevance of the double absorption peak, the food effect, the bioequivalence/therapeutic equivalence, the pediatric adapted dosing regimens, the study endpoints and the difference between performing studies at daytime or at nighttime. To fill in these gaps, additional well designed pharmacokinetic and pharmacodynamic studies in children should be performed.

Effect of vitamin D and omega-3 on nocturnal enuresis of 7-15-year-old children

INTRODUCTION

Nocturnal enuresis is known to be a common urinary bladder complication in children. Recent studies have associated vitamin D and omega-3 insufficiency with nocturnal enuresis.

AIM

This was a 2-month randomized, placebo-controlled, double-blind trial to measure the effects of vitamin D, omega-3 supplements, and their combination on nocturnal enuresis among 7-15-year-old children.

MATERIALS AND METHODS

Participants (180 children with nocturnal enuresis) were selected from children referred to the Pediatric ward of Imam Reza Clinic in Shiraz, Iran. Demographic information and anthropometric measures were taken. Fasting blood and urine samples were also collected, and serum vitamin D and urine prostaglandin E2 were measured before and after intervention. Enuretic children were randomly assigned to four groups: Group A, vitamin D (1000 IU/day); Group B, omega-3 (1000 mg/day); Group C, both omega-3 (1000 mg/day) and vitamin D (1000 IU/day); and Group D, placebo.

RESULTS

The results suggested that the study groups were not significantly different regarding demographic and anthropometric measures at baseline. Comparison of different groups revealed that 44.4% of participants in Group A, 28.2% of Group B and 45% of Group C were cured from enuresis (P = 0.03). Serum 25(OH) D was significantly increased in Group A, but urine prostaglandin E2 was not significantly decreased in response to supplementation. Although supplementation with both Group A and Group B were found to be effective, the combined intervention did not increase the effect of each intervention solely.

CONCLUSIONS

The results showed that supplementation with vitamin D and omega-3 could reduce the number of wet nights among 7-15-year-old children with nocturnal enuresis.

Stressful Events in Early Childhood and Developmental Trajectories of Bedwetting at School Age

Objective To examine whether early stressful events are associated with developmental trajectories of bedwetting. Methods This is a prospective cohort study comprising 8,761 participants from the Avon Longitudinal Study of Parents and Children. Stressful events were measured using a maternal questionnaire completed at 3 time points before their child was 4 years old. The association between stressful events and trajectories of bedwetting from 4 to 9 years was examined using multinomial regression. Results The association with stressful events was strongest for the frequent persistent bedwetting trajectory (wetting at least twice a week up to age 9). A 1 standard deviation increase in the stressful events score was associated with a 29% (13–47%) increase in the odds of experiencing frequent persistent bedwetting compared with normal attainment of nighttime bladder control. Conclusions Clinicians and parents should be aware that continence is a developmental outcome that is associated with high levels of stress in the family.

Advances in the management of primary monosymptomatic nocturnal enuresis in children

Intermittent incontinence of urine in a sleeping child who has previously been dry for less than 6 months without any other lower urinary tract symptoms is considered to be primary monosymptomatic nocturnal enuresis (PMNE). Although, most children outgrow PMNE with age, the psychological impact on the child warrants parental education and patient motivation and treatment. Motivational therapy, alarm therapy and drug therapy are the mainstay of treatment. Motivational and alarm therapy have better success rates than drug therapy alone. Desmopressin is the commonly used first-line drug and is best for short-term relief. Other drugs such as anti-cholinergics, imipramine and sertraline are used in resistant cases. This review focuses on the assessment and treatment of PMNE.

Tricyclic and related drugs for nocturnal enuresis in children

BACKGROUND

Enuresis (bedwetting) affects up to 20% of five year-olds and 2% of adults. Although spontaneous remission often occurs, the social, emotional and psychological costs can be great. Tricyclics have been used to treat enuresis since the 1960s.

OBJECTIVES

To assess the effects of tricyclic and related drugs compared with other interventions for treating children with enuresis.

SEARCH METHODS

We searched the Cochrane Incontinence Group Specialised Trials Register (containing trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, MEDLINE in process, ClinicalTrials.gov, WHO ICTRP and handsearching of journals and conference proceedings), on 30 November 2015, and reference lists of relevant articles.

SELECTION CRITERIA

We included all randomised and quasi-randomised trials comparing a tricyclic or related drug with another intervention for treating enuresis. We also included combination therapies that included tricyclics. We excluded trials for treating daytime wetting.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the quality of the eligible trials, and extracted data. We settled differences by discussion with a third review author.

MAIN RESULTS

Sixty-four trials met the inclusion criteria, involving 4071 children. The quality of many trials was poor, with comparisons addressed by single studies. Minor adverse effects were common, and reported in 30 trials. These included dizziness, headache, mood changes, gastrointestinal discomforts and neutropenia. More serious side-effects can occur but were not reported. Seven trials reported no adverse effects.Tricyclics are more effective than placebo, particularly for short-term outcomes. Compared to placebo, imipramine resulted in one fewer wet nights per week (mean difference (MD) -0.95, 95% confidence interval (CI) -1.40 to -0.50; 4 trials, 347 children), with fewer failing to achieve 14 consecutive dry nights (78% versus 95% for placebo, RR 0.74, 95% CI 0.61 to 0.90; 12 trials, 831 children). Amitriptyline and desipramine were more effective than placebo, but nortriptyline and mianserin showed no difference. Most tricyclics did not have a sustained effect after ceasing treatment, with 96% wetting at follow-up for imipramine versus 97% for placebo.Imipramine combined with oxybutynin is also more effective than placebo, with 33% failing to achieve 14 consecutive dry nights at the end of treatment versus 78% for placebo (RR 0.43, 95% CI 0.23 to 0.78; 1 trial, 47 children) and 45% wetting at follow-up versus 79% for placebo (RR 0.58, 95% CI 0.34 to 0.99; 1 trial, 36 children).There was insufficient evidence to judge the effect between different doses of tricyclics, and between different tricyclics. Treatment outcomes between tricyclic and desmopressin were similar, but were mixed when tricyclic was compared with an anticholinergic. However, when imipramine was compared with desmopressin plus oxybutynin (1 trial, 45 children), the combination therapy was more effective, with one fewer wet nights per week (MD 1.07, 95% CI 0.06 to 2.08) and 36% failing to achieve 14 consecutive dry nights versus 87% for imipramine (RR 2.39, 95% CI 1.35 to 4.25). Tricyclics were also more effective or showed no difference in response when compared to other drugs which are no longer used for enuresis.Tricyclics were less effective than alarms. Although there was no difference in the number of wet nights, 67% failed to achieve 14 consecutive dry nights for imipramine versus only 17% for alarms (RR 4.00, 95% CI 1.06 to 15.08; 1 trial, 24 children). Alarm therapy also had a more sustained effect after ceasing treatment with 100% on imipramine versus 58% on alarms wetting at follow-up (RR 1.67, 95% CI 1.03 to 2.69; 1 trial, 24 children).Imipramine was more effective than simple behavioural therapies during treatment, with one fewer wet nights per week compared with star chart plus placebo (MD -0.80, 95% CI -1.33 to -0.27; 1 trial, 250 children). At follow-up 40% were wet with imipramine versus 80% with fluids and avoiding punishment (RR 0.50, 95% CI 0.28 to 0.89; 1 trial, 40 children). However, imipramine was less effective than complex behavioural therapies, with 61% failing to achieve 14 consecutive dry nights for imipramine versus 33% for the three-step programme (RR 1.83, 95% CI 1.08 to 3.12; 1 trial, 72 children) and 16% for the three-step programme combined with motivational therapy and computer-led education (RR 3.91, 95% CI 2.30 to 6.66; 1 trial, 132 children) at the end of treatment, with similar results at follow-up.Tricyclics were more effective than restricted diet, with 99% failing to achieve 14 consecutive dry nights versus 84% for imipramine (RR 0.84, 95% CI 0.75 to 0.93; 1 trial, 147 children).There was insufficient evidence to judge the effect of tricyclics compared to the other miscellaneous interventions studied.At the end of treatment there were about two fewer wet nights for imipramine plus oxybutynin compared with imipramine monotherapy (MD -2.10, 95% CI -2.99 to -1.21; 1 trial, 63 children) and 48% on imipramine plus oxybutynin failed to achieve 14 consecutive dry nights compared with 74% on imipramine monotherapy (RR 0.68, 95% CI 0.50 to 0.92; 2 trials, 101 children). At follow-up, 45% on imipramine plus oxybutynin were wetting versus 83% on imipramine monotherapy (RR 0.55, 95% CI 0.32 to 0.92; 1 trial, 36 children).When imipramine combined with desmopressin was compared with imipramine monotherapy, there was no difference in outcomes. However, when imipramine plus desmopressin was compared with desmopressin monotherapy, the combination was more effective, with 15% not achieving 14 consecutive dry nights at the end of treatment for imipramine plus desmopressin versus 40% for desmopressin monotherapy (RR 0.38, 95% CI 0.17 to 0.83; 1 trial, 86 children). Tricyclics combined with alarm therapy were not more effective than alarm monotherapy, alarm combined with desmopressin or alarm combined with nortriptyline. The addition of a tricyclic to other behavioural therapies did not alter treatment response.

AUTHORS' CONCLUSIONS

There was evidence that tricyclics are effective at reducing the number of wet nights during treatment, but do not have a sustained effect after treatment stops, with most children relapsing. In contrast, there was evidence that alarm therapy has better short- and long-term outcomes. There was some evidence that tricyclics combined with anticholinergics may be more effective that tricyclic monotherapy.

Comorbidity of ADHD and incontinence in children

ADHD and incontinence are common childhood disorders which co-occur at much higher rates than expected by chance. The aim of this review was to provide an overview both of the comorbidity of nocturnal enuresis (NE), daytime urinary incontinence (DUI) and faecal incontinence (FI) in children with ADHD; and, vice versa, of the co-occurrence of ADHD in children with NE, DUI and FI. Most clinical studies have focussed on the association of ADHD and NE. Population-based studies have shown that children with DUI have an even greater risk for ADHD than those with NE. While children with FI have the highest overall comorbidity rates of psychological disorders, these are heterogeneous with a wide range of internalising and externalising disorders--not necessarily of ADHD. Genetic studies indicate that ADHD and NE, DUI and FI do not share the same genetic basis. The comorbidity is conferred by non-genetic factors. Possible aetiological and pathogenetic links between ADHD and incontinence are provided by neurophysiological, imaging and pharmacological studies. The co-occurrence has clinical implications: children with ADHD and NE, DUI and FI are more difficult to treat, show lower compliance and have less favourable treatment outcomes for incontinence. Therefore, both groups of disorders have to be assessed and treated specifically.

Central nervous system processing of emotions in children with nocturnal enuresis and attention-deficit/hyperactivity disorder

AIM

Nocturnal enuresis (NE) and attention-deficit/hyperactivity disorder (ADHD) are common in childhood. We analysed the central processing of emotions in children with NE, ADHD, NE + ADHD and controls.

METHODS

We examined 13 children with NE, 13 with ADHD, 14 with NE + ADHD and 14 controls. Acoustic evoked potentials were recorded using standardised methodology. For the event-related potentials, positive, negative and neutral pictures were presented and time intervals of 250-450, 450-650 and 650-850 msec evaluated. Hypotheses were tested with repeated-measures analyses of variance.

RESULTS

In the frontal region, children with NE showed more intense responses to positive and negative pictures than controls measured with event-related potentials. Viewing positive pictures, children with NE + ADHD differed from children with ADHD in the central and parietal and for all types of stimuli in the parietal region. Children with NE + ADHD elicited the strongest responses. Children with ADHD did not differ from controls. There was an unspecific interaction effect of the acoustic evoked potentials in children with NE compared to the controls.

CONCLUSION

Children with NE processed emotions differently from children with ADHD and controls. Children with NE + ADHD processed emotions the most intense, displaying interaction effects of the central nervous system that cannot be explained by each disorder alone.

Afferent pathway dysfunction in children with primary nocturnal enuresis

OBJECTIVES

To investigate afferent pathway dysfunction in children with primary nocturnal enuresis by measuring pudendal somatosensory evoked potential and tibial somatosensory evoked potential.

METHODS

Subjects with primary nocturnal enuresis, 36 boys and 18 girls, aged from 5 to 16 years, were enrolled in this study: 24 subjects had complicated primary enuresis (CPE) and 30 subjects had monosymptomatic primary enuresis (MPE). There were no differences in bodyweight or gender between the MPE and CPE groups (P > 0.05). All of the children underwent physical examination, urine analysis, urinary ultrasound and spinal magnetic resonance imaging. Only subjects without urological and neurological abnormalities (with the exception of spina bifida occulta, which was found in some of the patients) were included in this neurophysiological study.

RESULTS

There were 20 children who were positively recorded with pudendal somatosensory evoked potential in the CPE group, and all of the children in the MPE group were positively recorded (P < 0.05). Positive records of tibial somatosensory evoked potential were successfully achieved in both groups. Furthermore, the pudendal and tibial conductive velocity were slower as compared to the normal range, especially in children in the CPE group (P < 0.001).

CONCLUSIONS

Afferent pathway function may be impaired by some factors, which should be considered by both clinicians and parents.

A United Kingdom population-based study of intellectual capacities in children with and without soiling, daytime wetting, and bed-wetting

OBJECTIVE

The objective of this study was to examine differences in intellectual capacities between children with and without soiling, daytime wetting, and bed-wetting.

METHODS

This study was based on a population of >6000 children (age range: 7 years 6 months to 9 years 3 months; median: 7 years 6 months) from the United Kingdom-based Avon Longitudinal Study of Parents and Children. Data on wetting and soiling were obtained from a questionnaire completed by parents. The Wechsler Intelligence Scale for Children-Third Edition was administered at a research clinic.

RESULTS

Bed-wetting was associated with lower Wechsler Intelligence Scale for Children-Third Edition IQ scores compared with control subjects, particularly performance IQ. This difference remained after exclusion of children with an IQ of <70 and adjustment for gender, stressful life events, and sociodemographic background. There were fewer differences in IQ scores between children with and without soiling or daytime wetting. Co-occurring wetting and soiling were associated with lower IQ scores than isolated soiling, daytime wetting, or bed-wetting, but this was mostly attributable to an overrepresentation of children with an IQ of <70 in the co-occurrence group.

CONCLUSIONS

It is hypothesized that the differences in intellectual capacities between children with and without bed-wetting are associated with maturational deficits of the central nervous system. There was less evidence for differences in intellectual capacities between children with and without soiling and daytime wetting. The central nervous system is involved to a lesser extent in soiling and daytime wetting, because peripheral influences from the bladder and gut play a greater role.

Primary nocturnal enuresis: omega-3 fatty acids may be of therapeutic value

Primary nocturnal enuresis (PNE), or bed-wetting, is a distressing urinary condition which can persist through childhood and beyond. Altered prostaglandin and nitric oxide production have been observed in children with PNE, and prostaglandin inhibitors are known to be of therapeutic value. Omega-3 fatty acids have the potential to influence the symptoms of PNE by inhibition of prostaglandin and renal nitric oxide production. In addition, children with PNE have an inappropriate startle response and an apparent maturational delay of the central nervous system. Research clearly shows that omega-3 fatty acids play a critical role in the development and function of the central nervous system. It is our contention that inadequate omega-3 intake may play a role in the lack of inhibitory input to the startle and micturition centers in PNE.

[Diagnostics of functional bladder disorders in children]

Functional bladder disorders are one of the most frequent urinary disorders in children. Today, we strictly differentiate enuresis from pediatric urinary incontinence. In most cases, these classifications will be achieved with non-invasive, primary diagnostic procedures. In monosymptomatic enuresis, further invasive examinations are not necessary. However, in pediatric urinary incontinence invasive diagnostic tools such as video-urodynamic studies are mandatory for a correct classification. Recently established guidelines on the diagnostic procedures for the evaluation of pediatric bladder disorders will help to standardize the diagnostic work-up.

Topographic abnormalities in event-related potentials in children with monosyptomatic nocturnal enuresis

AIMS

A functional maturational delay in the central nervous system is dwelled upon in the pathogenesis of monosymptomatic nocturnal enuresis (MNE). In this study we studied whether according to controls N200 and P300, components of the event-related potential (ERP), which is related to aspects of cognitive processing, showed any difference in its topographic distribution in children within the age group 10-13 with monosymptomatic nocturnal enuresis and discussed its relation to the pathogenesis of MNE.

METHODS

We performed P300 in 18 patients with MNE and in 16 age-matched healthy subjects. P300 were evoked by an auditory oddball paradigm consisting of 150 tone bursts (80% 1 kHz; 20% 2 kHz). The latencies of the N200 and the P300 waves and the amplitude of the P300 wave were measured.

RESULTS

There was no statistical difference between the enuretic group and the controls in N200 and P300 latency and amplitude in the midline frontal (Fz), central (Cz), and parietal (Pz) recording site of the 10-20 International System. In the enuretic group while P300 amplitude in the Fz site was significantly less than the P300 amplitude in the Cz site, there was no statistical difference between the Fz and Pz P300 amplitude values.

CONCLUSIONS

When different levels of maturational delay are considered in MNE, it may be claimed that maturational delay in children whose enuresis lasts until older ages will be different from those whose enuresis ends at an early age. The determination of P300 amplitude in parietal records being less in enuretics when compared to the controls may show that there are regional differences in stimuli processing rate/quality.

Tricyclic and related drugs for nocturnal enuresis in children

BACKGROUND

Enuresis (bedwetting) is a socially disruptive and stressful condition which affects around 15-20% of five year olds, and up to 2% of young adults.

OBJECTIVES

To assess the effects of tricyclic and related drugs on nocturnal enuresis in children, and to compare them with other interventions.

SEARCH STRATEGY

We searched the Cochrane Incontinence Group trials register (December 2002) and the reference lists of relevant articles including two previously published versions of this review. Date of the most recent searches: December 2002.

SELECTION CRITERIA

All randomised and quasi-randomised trials of tricyclics or related drugs for nocturnal enuresis in children were included in the review. Comparison interventions included placebo, other drugs, alarms, behavioural methods or complementary/miscellaneous interventions. Trials focused solely on daytime wetting were excluded.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed the quality of the eligible trials, and extracted data.

MAIN RESULTS

Fifty four randomised trials met the inclusion criteria, involving 3379 children. The quality of many of the trials was poor. Most comparisons or outcomes were addressed only by single trials. Treatment with most tricyclic drugs (such as imipramine, amitriptyline, viloxazine, nortriptyline, clomipramine and desipramine) was associated with a reduction of about one wet night per week while on treatment (eg imipramine compared with placebo, weighted mean difference (WMD) -1.19, 95% CI -1.56 to -0.82). The exception was mianserin, where results from one small trial did not reach statistical significance. About a fifth of the children became dry while on treatment (relative risk for failure (RR) 0.77, 95% CI 0.72 to 0.83), but this effect was not sustained after treatment stopped (eg imipramine versus placebo, RR 0.98, 95% CI 0.95 to 1.03). There was not enough information to assess the relative performance of one tricyclic against another, except that imipramine was better than mianserin. The evidence comparing desmopressin with tricyclics was unreliable or conflicting, but in one small trial all the children failed or relapsed after stopping active treatment with either drug.The evidence comparing tricyclics with alarms was also unreliable or conflicting during treatment. In one small trial all the children failed or relapsed after tricyclics stopped, compared with about half after alarms. This result was compatible with the results in the Cochrane review of alarm treatment, which found that about half the children remained dry after alarm treatment was finished. There was a little evidence from single trials to suggest that imipramine might be better than a simple reward system with star charts during treatment; worse than a complex intervention involving education, counseling, waking and retention control training; better than a restricted diet; and worse than hypnosis. However, these results need to be confirmed by further research.

REVIEWER'S CONCLUSIONS

Although tricyclics and desmopressin are effective in reducing the number of wet nights while taking the drugs, most children relapse after stopping active treatment. In contrast, only half the children relapse after alarm treatment. Parents should be warned of the potentially serious adverse effects of tricyclic overdose when choosing treatment. Further research is needed into comparisons between drug and behavioural or complementary treatments, and should include relapse rates after treatment is finished.

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.

Relationships among nocturnal urinary volume, bladder capacity, and nocturia with and without water load in nonenuretic children

OBJECTIVES

To evaluate the relationships among nocturnal urinary volume (NUV), bladder capacity, and nocturia in nonenuretic children with and without water load.

METHODS

We evaluated 72 healthy nonenuretic volunteers. The NUV and bladder capacity were measured for 2 nights at volunteers' homes with and without water load.

RESULTS

Of the 72 nonenuretic children, 45 (63%) were classified into the large NUV group in which the NUV with water load was more than the upper limit of the 95% confidence interval of NUV in Japanese nonenuretic children, and the other 27 (37%) were classified into the small NUV group. In the large NUV group, 33 (73%) had one or two episodes of nocturia because of water intake, and 12 (27%) did not. The nocturnal bladder capacity in the latter 12 children was significantly larger than that in the former 33, although no significant differences were found in functional bladder capacity and NUV with water intake.

CONCLUSIONS

Most nonenuretic children were able to cope with the physiologic loading of water that would cause bedwetting in enuretic children. After water loading, three quarters of the nonenuretic children were able to awake easily because of the need to urinate with a certain volume of urine in the bladder, and the one quarter who did not awake were able to hold more urine in their bladder in the sleep state.

Night-time polyuria and urine hypo-osmolality in enuretics identified by nocturnal sequential urine sampling--do they represent a subset of relative ADH-deficient subjects?

Early morning urine osmolality was tested in two urinary specimens, one taken immediately upon awakening and the other approximately 30 min thereafter, in 52 enuretic and 15 non-enuretic children. In a follow-up study, using the same study population, urine osmolality and volume were measured sequentially at 3-h intervals at 19.00, 22.00, 01.00, 04.00 and 07.00 h. Thereafter, all enuretics were treated by intranasal DDAVP for a 6-month period. There were no differences in urinary osmolality between enuretic and non-enuretic children when comparing the two early morning specimens. Nor were there any differences between groups in urine osmolalities at 19.00, 01.00 and 07.00 h. In contrast, at 04.00 h, urine osmolality was significantly lower in 17 of 52 enuretics [designated as ADH-negative (ADH-)] compared to the remaining enuretics [designated as ADH-positive (ADH+)] and non-enuretic children (610 +/- 251 vs 995 +/- 195 and 1089 +/- 195 mosmol/kg H2O, respectively, p < 0.05). This decreased osmolality was paralleled by an increase in urine production during the time period 01.00-04.00 (83 +/- 24 vs 52 +/- 18 and 45 +/- 22 ml, respectively, p < 0.05). At the end of the 6-month period of DDAVP treatment, the percentage response was similar between the ADH- and ADH+ enuretics (79% vs 75%). However, the time taken to achieve a response was quicker in the ADH- subjects. These data suggest the existence of a subgroup of enuretics whose underlying pathophysiology is the development of nocturnal polyuria probably due to a relative night-time ADH deficiency. Nocturnal sequential monitoring of urinary osmolality, as described above, allows identification of this subgroup.

[Treatment of isolated nocturnal enuresis: alarm or desmopressin?]

BACKGROUND

Monosymptomatic nocturnal enuresis is common in healthy school children. Treatment is often required because of social and psychological convenience. We therefore conducted a randomized prospective trial using either desmopressin (D) or alarm (A).

PATIENTS AND METHODS

Patients (n = 135) aged 6 to 16 years were enrolled between January 1992 and December 1994. Desmopressin (Minirin spray, Ferring SA) was given intranasally at a dose of 20 micrograms at bedtime and increased to 40 micrograms after 2 weeks if partial result was obtained. The alarm was a pad-bell device (Wet-stop, Sega) and the sound source was attached to the upper part of the pajamas. Inclusion criteria were: primary monosymptomatic nocturnal enuresis in healthy children, age > or = 6 years, absence of previous treatment using either desmopressin or alarm. The aim of the treatment was to achieve 100% dry nights. Patients were evaluated after 15 days on therapy by phone call and thereafter by attending the outpatient clinic at 2-3 and 4-6 months. At the time of the second evaluation, a switch from alarm to desmopressin (or vice-versa) was proposed to those who did not respond to the initial treatment.

RESULTS

In group D (n = 62), only 27 children were included since 12 (19%) were switched to alarm and 23 (37%) were excluded because they were either non-compliant or lost to follow-up. In group A (n = 73), only 31 were included since six (8%) were switched to desmopressin and 36 (49%) were excluded for the same reasons as in group D. Prior to inclusion, the percentage of dry nights was 21% in group D and 14% in group A. After 15 days on therapy, patients from group D achieved 80% dry nights compared to 50% in group A (P = 0.001). After 3 months, patients from group D attained 85% dry nights vs 90% in group A. After 6 months, children from group A achieved 94% dry nights vs 78% in group D (P = 0.01).

CONCLUSION

Desmopressin offers better short-term results than enuresis alarm but the latter is significantly more efficient in the long term. In France, the alarm device is not reimbursed by the national health service and therefore is poorly accepted, as suggested from the high rate of patients lost to follow-up.

Evaluation of antidiuretic hormone before and after long-term treatment with desmopressin in a group of enuretic children

OBJECTIVE

To determine the effect of long-term desmopressin therapy in enuretic patients on the levels of antidiuretic hormone (ADH) during and after the end of therapy.

PATIENTS AND METHODS

The study comprised 25 outpatients (18 boys and seven girls) aged 8-12 years at the start of therapy and 12-16 years at the end. The morning (08.00 hours) plasma ADH level was determined before treatment (T0) with desmopressin and 2 years after (T1) ending the therapy. Seven of the 25 patients evaluated had monosymptomatic (simple enuresis, SE) and 18 had other symptoms (complex enuresis, CE).

RESULTS

In the patients with SE, the mean (SD) duration of therapy was 305 (183) days and they were reevaluated 2.5 (0.67) years later. Of 18 patients with CE, eight were treated only with desmopressin for 204 (117) days. In 10 with an incomplete response after 30 days with only desmopressin, oxybutynin (5 mg twice daily) was added; the duration of their therapy was 255 (152) days and they were re-evaluated 3.9 (0.6) years later. The mean (SD) ADH level in those with SE and CE was 2.14 (0.93) ng/L and 2.53 (1.16) ng/L), respectively, both significantly lower (P < 0.001) than in controls, at 5.1 (1.6) ng/L. On re-evaluation at T1, there was a significant (P < 0.001) increase in ADH levels over those at T0 in both groups, at 5.2 (0.8) and 5.3 (1.9) ng/L, respectively.

CONCLUSION

These results seem to confirm the role played by ADH in the pathophysiology of enuresis.