Simultaneous registration of sleep-stages and bladder activity in enuresis

[Primary monosymptomatic enuresis: diagnostics and therapy]

Nocturnal enuresis is one of the most common problems in childhood. In this article a standardized terminology for basic diagnostics additionally to extended diagnostics will be presented. Depending on the findings a specialized therapy can be performed. Besides drug therapy with antidiuretic hormone (ADH) sleep arousal devices can be used and the combination of both approaches also shows excellent results. At the end of therapy a protracted withdrawal shows better results than abrupt cessation.

Sleep deprivation induces excess diuresis and natriuresis in healthy children

Urine production is reduced at night, allowing undisturbed sleep. This study was undertaken to show the effect of sleep deprivation (SD) on urine production in healthy children. Special focus was on gender and children at an age where enuresis is still prominent. Twenty healthy children (10 girls) underwent two 24-h studies, randomly assigned to either sleep or SD on the first study night. Diet and fluid intake were standardized. Blood samples were drawn every 4 h during daytime and every 2 h at night. Urine was fractionally collected. Blood pressure and heart rate were noninvasively monitored. Blood was analyzed for plasma antidiuretic hormone (AVP), atrial natriuretic peptide (ANP), angiotensin II, aldosterone, and renin. Urine was analyzed for aquaporin-2 and PGE2. Successful SD was achieved in all participants with a minimum of 4 h 50 min, and full-night SD was obtained in 50% of the participants. During SD, both boys and girls produced markedly larger amounts of urine than during normal sleep (477 ± 145 vs. 291 ± 86 ml, P < 0.01). SD increased urinary excretion of sodium (0.17 ± 0.05 vs. 0.10 ± 0.03 mmol·kg−1·h−1) whereas solute-free water reabsorption remained unchanged. SD induced a significant fall in nighttime plasma AVP ( P < 0.01), renin ( P < 0.05), angiotensin II ( P < 0.001), and aldosterone ( P < 0.05) whereas plasma ANP levels remained uninfluenced ( P = 0.807). Nighttime blood pressure and heart rate were significantly higher during SD (mean arterial pressure: 78.5 ± 8.0 vs. 74.7 ± 8.7 mmHg, P < 0.001). SD leads to natriuresis and excess diuresis in healthy children. The underlying mechanism could be a reduced nighttime dip in blood pressure and a decrease in renin-angiotensin-aldosterone system levels during sleep deprivation.

Sleep and sleepiness in children with nocturnal enuresis

STUDY OBJECTIVES

To assess if sleep patterns and sleepiness are compromised in children with nocturnal enuresis (NE), in comparison with normal control subjects, and to evaluate the role of enuresis-related events during sleep.

DESIGN

Assessment of natural sleep patterns at home in a sample of children referred to enuresis clinics and controls.

SETTING

Children's homes.

PARTICIPANTS

Thirty-two children (19 boys and 13 girls aged 5.1 to 9.1 years) who suffer from primary NE and 94 healthy control subjects (49 boys and 45 girls aged 5 to 8.58 years).

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Sleep measures were derived from 3 to 5 nights of actigraphy and daily logs. Additional information on events related to enuresis and daytime sleepiness was collected using daily reports. Children with NE slept significantly worse than did the control subjects. Their compromised sleep patterns were reflected in a higher number of actigraphic nighttime awakenings, the reduced percentages of motionless sleep, the higher number of reported nighttime awakening, and the increased sleep latency. Children with NE also reported higher levels of sleepiness in the morning and in the evening.

CONCLUSIONS

Compared with the sleep of control subjects, the natural sleep of children with NE is significantly more fragmented, and the children with NE experience higher levels of daytime sleepiness. This phenomenology is associated with bedwetting episodes and attempts to keep the child dry during the night. These findings may suggest that children with NE suffer from sleep fragmentation, which may explain their higher arousal threshold. These findings have clinical implications for enuresis management.

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.

Molecular genetics of nocturnal enuresis: linkage to a locus on chromosome 22

The aim of this study was to investigate linkage of nocturnal enuresis to a locus on chromosome 22 in 35 German families and to analyse associations with the clinical phenotype. One hundred and sixty-seven enuretic children aged 5-11 years were examined using a somatic, psychiatric and psychological diagnostic protocol; a detailed pedigree over three generations was also compiled. Forty-two children (mean age: 8.11 years) were selected for further molecular genetic examination. EDTA blood samples were taken from the patients and 130 relatives, and polymorphisms of the microsatellite markers D22S446, D22S156 and D22S257 on chromosome 22 were analysed. Positive linkage was found in 11 families of 14 children, indicating that 39.3% of families were compatible with linkage to the markers on chromosome 22. The phenotype included primary nocturnal enuresis and combined day and night wetting. The results for chromosome 22, as with previous loci for nocturnal enuresis on chromosomes 8, 12 and 13, support the hypothesis for genetic and clinical heterogeneity.

Pathophysiology and impact of nocturnal enuresis

Nocturnal enuresis in children is not a psychogenic disorder. It is caused by a hereditary delay in maturation of the somatic mechanisms (reduction of nocturnal urine production and a normal arousal to a full bladder) which prevent the child from wetting the bed. Traditionally, doctors treating bedwetting children have used an expectant attitude, because nocturnal enuresis has been looked upon as self-limiting and harmless. According to recent research this is not true. More than 5% of children and 0.5% of the adult population report nocturnal enuresis, meaning that 10% of enuretic children will remain bedwetters for life if left untreated, and nocturnal enuresis is perceived as a shameful condition, giving a significant impairment of self-esteem at an age when an intact self-image is extremely important for an optimal development of the child's personality. Treatment should be given when the enuretic child wants to sleep dry.

Nocturnal enuresis: sleep disturbance and behavioural patterns

Sleep pattern and behaviour was studied in 88 children with nocturnal enuresis and compared with 340 non-enuretic children. There were no differences in common psychosomatic complaints. Enuresis was almost three times more common in the families of the enuretic children than in the families of their non-enuretic peers. The enuretics were considered deep sleepers by their parents. A wake-up test showed that they were more difficult to arouse at night compared with controls (p < 0.001). These results demonstrate that enuresis has a strong genetic link and enuretics are characterized as deep sleepers but do not display different day-time behavioural patterns compared with their non-enuretic peers.

Personality traits in young adults with a history of conditioning-treated childhood enuresis

At follow-up, 29 young adults treated previously (ages 7-14 years) for nocturnal enuresis by means of conditioning, mostly with a bed alarm, had shown no excess of mental abnormalities, including psychosomatic symptoms. To investigate whether the probands displayed personality traits that could be related to the former enuresis and its treatment, they were asked to answer a mailed questionnaire that attempts to find deviations of personality, the Karolinska Scales of Personality. The scores were compared with those of a group drawn from the general population in the same geographical area and matched for sex and age. The enuresis group was found to have moderately (but significantly) lower scores on socialization and higher scores on suspicion. Possible causes for these findings are discussed. It is concluded that conditioning therapy, which is usually successful in rapidly alleviating enuresis, can also be regarded as a safe treatment. According to this study, it does not seem to leave unwanted aftereffects that could be interpreted as expressions of persisting psychological conflicts.

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.

Urethral pressure variations in healthy females during rest and sleep

Recent studies have shown the occurrence of rhythmic urethral pressure variations (UPV) in the normal female urethra in the awake state. The nature of these variations still needs further elucidation. In this study we investigated the changes in urethral pressure (UP) and in UPV as they occur in healthy females awake and asleep. UPV, intravesical-(IVP) and rectal pressure (RP), together with anal electromyography (EMG) and electroencephalography (EEG) were measured in 10 healthy fertile female volunteers. The registration was done in the awake state, during falling asleep and during sleep. During falling asleep the average urethral pressure as well as the UPV amplitude and frequencies decreased and remained at a lower stable level during sleep. Urethral pressure and its variations seemed to be interrelated since the UPV frequency and amplitude decreased when the average UP decreased. From this study it appears that urethral pressure is influenced by extrinsic factors such as the waking, resting and sleeping states. Although some extrinsic modulation of urethral pressure variations occurs, their persistance in sleep suggests their local nature.