Neurophysiology of nocturnal enuresis: evoked potentials and prepulse inhibition of the startle reflex

Periaqueductal gray subregions connectivity and its association with micturition desire-awakening function

Existing literature strongly supports the idea that children with primary nocturnal enuresis (PNE) have brainstem abnormalities. However, the connection between pre-micturition arousal responses and brain functional connectivities is still not clearly defined. Our study investigated the correlation between the gradations of micturition desire-awakening (MDA) functionality and the functional connectivity of the midbrain periaqueductal gray (PAG), a pivotal brainstem hub implicated in the neural regulation of micturition in humans. Neuroimaging and behavioral data from 133 patients with PNE and 40 healthy children were acquired from functional magnetic resonance imaging (fMRI) and precise clinical observations, respectively. The whole-brain correlation analyses were undertaken to elucidate the complex connectivity patterns between the subregions of PAG and the cerebral cortex, with a focus on their correlation to the spectrum of MDA functionality. A positive correlation was identified between MDA dysfunction and the resting-state functional connectivity (RSFC) between the left ventrolateral periaqueductal gray (vlPAG) and the right temporal pole of the superior temporal gyrus. Conversely, a negative correlation was observed between MDA dysfunction and the RSFC of the right vlPAG with the right superior parietal lobule. Additionally, MDA dysfunction exhibited a negative association with the RSFC between the dorsomedial PAG (dmPAG) and the right inferior parietal lobule. These findings may indicate that the specific signal from a distended bladder is blocked in the PAG and its functional connectivity with the executive function, attention, and default mode networks, ultimately leading to impaired arousal and bladder control. This revelation underscores potential neural targets for future therapeutic interventions.

Clinical phenotyping of children with nocturnal enuresis: A key classification to improve the approach

INTRODUCTION

The literature shows that nocturnal enuresis is not an isolated phenomenon of urinary loss during sleep, but encompasses a set of systemic clinical manifestations that significantly influence children's quality of life and development. However, the understanding of the clinical and physiological relationship of these systemic manifestations remains a clinical challenge. The recognition of these manifestations and their subsequent categorisation, may provide better insights into integrated clinical manifestations, facilitating the understanding of pathophysiological mechanisms, and promote increased assertiveness in the assessment and the selection of appropriate therapies.

OBJECTIVE

The aim of this study is to develop a phenotyping model for children with nocturnal enuresis based on evidence.

METHODS

This study presents a clinical phenotyping model for children with nocturnal enuresis based on an analytical and methodological review of the literature, about nocturnal enuresis and its associated clinical manifestations. There was a bibliometric analysis carried out to better analyse outcomes. After reading and analysing the literature, the clinical manifestations were categorised into domains and submitted to the validation of an expert committee with extensive experience in their specific area of expertise. A visual representation of the categorised model was developed to make the phenotyping concept easily understandable to all professionals.

RESULTS

The clinical manifestations related to nocturnal enuresis have been categorised according to frequency and relation found in the literature and validation by an expert committee and the development of the phenotyping model for children with nocturnal enuresis was completed.

CONCLUSION

The present study developed an evidence-based phenotyping model for children with nocturnal enuresis.

Prevalence of Lower Urinary Tract Symptoms in Children with Attention-Deficit/Hyperactivity Disorder: Comparison of Hospital and Population-Based Cohorts of 13,000 Patients

Background: This study investigates the prevalence of lower urinary tract symptoms (LUTS) in school-age children with Attention-Deficit/Hyperactivity Disorder (ADHD) based on hospital-based and population-based cohorts. Methods: The hospital-based sample comprised 42 children with ADHD and 65 without ADHD aged 6−12 years. Voiding dysfunction was assessed by the Dysfunctional Voiding Scoring System (DVSS) questionnaire. We compared the baseline data, DVSS score, and uroflowmetry between the two groups. For the population-based cohort in the national insurance database, we included 6526 children aged 6−12 years, whose claims record included the diagnosis of ADHD, and another 6526 control subjects matched by gender and age. We compared the presence of LUTS diagnosis codes between the two groups. Results: Our results showed that, for the hospital-based cohort, the mean total DVSS score and the proportion of significant LUTS in children in the ADHD group were significantly higher than in subjects in the non-ADHD group. The DVSS subscales showed that the item “I cannot wait when I have to pee” item was significantly higher in the ADHD group (1.62 ± 1.17 vs. 0.90 ± 1.09, p = 0.002). For the population-based cohort, children with ADHD had a significantly higher likelihood of storage symptoms (5.53% vs. 2.91%, p < 0.001) and enuresis (3.28% vs. 1.95%, p < 0.001) compared with those of the no ADHD group. Conclusions: Children with ADHD have a higher prevalence of significant LUTS, especially storage symptoms and enuresis, than children without ADHD. The observed correlations between ADHD and LUTS provided the supporting evidence to evaluate the concomitant voiding dysfunction in children with ADHD.

α6-Containing GABAA Receptors: Functional Roles and Therapeutic Potentials

GABAA receptors containing the α6 subunit are highly expressed in cerebellar granule cells and less abundantly in many other neuronal and peripheral tissues. Here, we for the first time summarize their importance for the functions of the cerebellum and the nervous system. The cerebellum is not only involved in motor control but also in cognitive, emotional, and social behaviors. α6βγ2 GABAA receptors located at cerebellar Golgi cell/granule cell synapses enhance the precision of inputs required for cerebellar timing of motor activity and are thus involved in cognitive processing and adequate responses to our environment. Extrasynaptic α6βδ GABAA receptors regulate the amount of information entering the cerebellum by their tonic inhibition of granule cells, and their optimal functioning enhances input filtering or contrast. The complex roles of the cerebellum in multiple brain functions can be compromised by genetic or neurodevelopmental causes that lead to a hypofunction of cerebellar α6-containing GABAA receptors. Animal models mimicking neuropsychiatric phenotypes suggest that compounds selectively activating or positively modulating cerebellar α6-containing GABAA receptors can alleviate essential tremor and motor disturbances in Angelman and Down syndrome as well as impaired prepulse inhibition in neuropsychiatric disorders and reduce migraine and trigeminal-related pain via α6-containing GABAA receptors in trigeminal ganglia. Genetic studies in humans suggest an association of the human GABAA receptor α6 subunit gene with stress-associated disorders. Animal studies support this conclusion. Neuroimaging and post-mortem studies in humans further support an involvement of α6-containing GABAA receptors in various neuropsychiatric disorders, pointing to a broad therapeutic potential of drugs modulating α6-containing GABAA receptors. SIGNIFICANCE STATEMENT: α6-Containing GABAA receptors are abundantly expressed in cerebellar granule cells, but their pathophysiological roles are widely unknown, and they are thus out of the mainstream of GABAA receptor research. Anatomical and electrophysiological evidence indicates that these receptors have a crucial function in neuronal circuits of the cerebellum and the nervous system, and experimental, genetic, post-mortem, and pharmacological studies indicate that selective modulation of these receptors offers therapeutic prospects for a variety of neuropsychiatric disorders and for stress and its consequences.

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.

Non-dipping phenomenon effects in monosymptomatic nocturnal enuresis treatment?

BACKGROUND

Monosymptomatic enuresis nocturna patients are shown to have disrupted blood-pressure regulation accompanying polyuria. In our study, we aimed to research the desmopressin response of enuresis patients with blood-pressure regulation problems.

METHODS

The study included 175 patients, aged from 6-15 years, with a diagnosis of monosymptomatic enuresis nocturna. Before treatment, 24 h ambulatory blood-pressure monitoring (ABPM) was used to identify 52 non-dipper patients and 73 patients with normal results. The responses to desmopressin treatment and clinical and demographic characteristics affecting response were compared.

RESULTS

The response to desmopressin treatment was found to be significantly low in the patients who were non-dippers on 24 h ABPM before treatment compared to those with normal ABPM results (P < 0.05). Similarly, the waking problems in the non-dipper group were found to be high by a significant degree (P < 0.05). In the non-dipper group, the systolic non-dipping rate was higher.

CONCLUSIONS

Before desmopressin use, assessment of patients with a 24 h ABPM may be beneficial to select the method to be used for treatment.

Functional connectivity of thalamus in children with primary nocturnal enuresis: results from a resting-state fMRI study

Primary nocturnal enuresis (PNE) is characterized by a low cure rate and a high reoccurrence rate, since its underlying mechanism remains unclear. Based on the recent studies that thalamus plays an important role in waking up a sleeping person, here we further investigate the functional connectivity (FC) information between thalamus and other brain regions, in order to make better understanding of the PNE's pathogenesis. In this study, we enrolled 30 children diagnosed with PNE and 30 typically developing children that are age and sex matched, the thalamus-based FC estimates were extracted at the resting-state. Experiments showed that for children with PNE, there were four brain regions found with a reduced connection efficiency with thalamus, that were cerebellum posterior lobe, frontal lobe, parietal lobe and precentral gyrus. It can be concluded that these relevant regions might induce an arousal disorder, and therefore further lead to PNE. This finding also provides a new insight in the pathophysiology of PNE.

Pathogenesis and brain functional imaging in nocturnal enuresis: A review

Nocturnal enuresis is a common and distressing developmental disease, which may cause various degrees of psychosocial stress and impairment to self-esteem in affected children as well as agitation to their parents or caregivers. Nevertheless, the etiology and pathogenesis of nocturnal enuresis are not understood. Currently, nocturnal enuresis is generally considered a multifactorial disease associated with a complex interaction of somatic, psychosocial, and environmental factors. A variety of postulations have been proposed to explain the occurrence and progression of nocturnal enuresis, including hereditary aberration, abnormal circadian rhythm of antidiuretic hormone secretion during sleep, bladder dysfunction, abnormal sleep, difficulties in arousal, neuropsychological disorders, and maturational delays of the brain. In recent decades, the introduction of functional neuroimaging technologies has provided new approaches for uncovering the mechanisms underlying nocturnal enuresis. The main neuroimaging modalities have included brain morphometry based on structural magnetic resonance imaging (MRI), task-based and event-related functional MRI (fMRI), and resting-state fMRI. The relevant studies have indicated that nocturnal enuresis is associated with functional and structural alterations of the brain. In this review, we briefly summarized the popular hypotheses regarding the pathogenesis of nocturnal enuresis and the current progress of functional neuroimaging studies in examining the underlying mechanisms thereof.

Nocturnal events in children: When and how to evaluate

Nocturnal events of wide variety and concern are frequently reported by patients and their caregivers. To evaluate suspected abnormal events, primary care physicians must first be familiar with normal behaviors, movements and breathing patterns. Abnormal nocturnal events can then be categorized as nocturnal seizure, parasomnia, sleep-related movement disorder or sleep-related breathing disorder. Diagnoses in the above categories can be made clinically; however, it is important to know when to refer for additional evaluation. Comprehensive literature review was undertaken of nocturnal and sleep-related disorders. This guide reviews nocturnal seizures, normal and abnormal nonepileptic movements and behaviors, discusses broad indications for referral for electroencephalography (EEG) or polysomnography (PSG), and guides counseling and management for patients and their families, ultimately aiding in interpretation of both findings and prognosis. Epilepsy syndromes can result in seizures during sleep or adjacent periods of wakefulness. Parasomnias and sleep-related movement disorders tend to also occur in childhood and may be distinguished clinically. Referral to additional specialists for specific studies including EEG or PSG can be necessary, while other times a knowledgeable and vigilant clinician can contribute to a prompt diagnosis based on clinical features. Nocturnal events often can be managed with parental reassurance and watchful waiting, but treatment or evaluation may be needed. Sleep-related breathing disorders are important to recognize as they present very differently in children than in adults and early intervention can be life-saving. This review should allow both primary and subspecialty non-neurologic pediatric and adolescent health care providers to better utilize EEG and PSG as part of a larger comprehensive clinical approach, distinguishing and managing both epileptic and nonepileptic nocturnal disorders of concern while fostering communication across providers to facilitate and coordinate better holistic long-term care of pediatric and adolescent patients.

Sleep Architecture in Valproate-Induced Nocturnal Enuresis in Primary School and Preschool Children

Nocturnal enuresis is one of the side effects of valproic acid treatment, and generally underdiagnosed by clinicians. Studies reported that a variable incidence of valproic acid-induced nocturnal enuresis is 2.2% to 24% with unclear explanations of the reasons behind valproic acid-induced nocturnal enuresis. A retrospective study was carried out on 260 children (aged 5-12 years) diagnosed with idiopathic epilepsy, treated with valproic acid to evaluate the nocturnal enuresis secondary to valproic acid, and to discuss the characteristics of their sleep architecture. Nocturnal enuresis was reported in 28 (10.7%) patients after a mean exposure time to valproate of 18.78±8.4 days. Nocturnal enuresis was significantly associated with younger age and serum level of valproate (P = .05). The polysomnographic study suggested that the underlying mechanism may be related to impaired sleep efficiency, frequent arousals, prolonged sleep latency, snoring, or increased sleep depth which may impair a child's ability to awaken to the sense of bladder fullness or contractions.Clinical trial registration: ClinicalTrials.gov identifiers: NCT04191863.

BDNF and NGF gene polymorphisms and urine BDNF-NGF levels in children with primary monosymptomatic nocturnal enuresis

INTRODUCTION

The pathophysiology and genetic influences in nocturnal enuresis have not been fully elucidated. Delayed neuronal maturation has been suggested as a pathogenetic mechanism in primary monosymptomatic nocturnal enuresis (PMNE). Brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) are neurotrophins affecting maturation of the nervous system.

OBJECTIVE

The aim of this preliminary study was to investigate BDNF and NGF gene polymorphisms and urine levels of BDNF and NGF in children with PMNE as a first time.

STUDY DESIGN

The single-nucleotide polymorphisms of BDNF (rs6265:G > A:Val66Met; rs8192466:C > T:Thr2Ile) and NGF (rs6330:C > T:Ala35Val, rs11466112:C > T:Arg221Trp) were investigated by comparing 104 children with PMNE and 140 healthy control subjects. Children with non-PMNE were excluded. DNA isolation and detection of polymorphisms were performed by real-time polymerase chain reaction. In addition, urine BDNF and NGF levels of 47 PMNE and 29 healthy children were measured by enzyme-linked immunosorbent assay method and normalized to urine creatinine (Cr) concentration for comparisons.

RESULTS

There were no differences in genotype and allele frequencies of BDNF rs6265 and NGF rs6330 polymorphisms between patients with PMNE and the control group (P > 0.05). No mutant alleles were found in BDNF rs8192466 and NGF rs11466112 polymorphisms in either group. Children with PMNE had higher urine BDNF/Cr (0.020 ± 0.010 vs 0.010 ± 0.002; P = 0.008) and NGF/Cr ratio (3.01 ± 1.87 pg/mg vs 1.77 ± 0.26 pg/mg; P = 0.002) compared with the control subjects. However, no significant differences were found in BDNF/Cr and NGF/Cr values between GG, GA, and AA genotypes of BDNF rs6265 polymorphism and CC and CT genotypes of NGF rs6330 polymorphism (P > 0.05).

DISCUSSION

In this study, no association of BDNF and NGF gene polymorphisms with PMNE was found, and urine neurotrophin concentrations were not directly influenced by investigated polymorphisms. Although, previously increased urine neurotrophin secretion has been found in detrusor overactivity, bladder inflammation, and dysfunctional voiding, this preliminary results also showed an increase in neurotrophins in PMNE. Higher urine neurotrophin levels may be related to delayed and continued neuronal maturation or increased production of neurotrophins in the bladder. The increased urine neurotrophins in PMNE may be an indicator of increased sensory nerve excitability of the bladder, contributing to the development of enuresis.

CONCLUSION

This study showed that investigated neurotrophin gene polymorphisms did not make a significant contribution to the development of PMNE, but urine levels of neurotrophin gene products were higher in PMNE. Owing to the complexity and heterogeneity of genotype-phenotype relationships in enuresis, further studies are needed in PMNE.

[Event-related potentials of working memory impairment in children with primary nocturnal enuresis]

OBJECTIVE

To study the cognitive neural mechanism of working memory impairment in children with primary nocturnal enuresis using event-related potential (ERP).

METHODS

A total of 14 children with primary nocturnal enuresis were enrolled as enuresis group, and 14 normal children were enrolled as control group. The learning-recognition task test was applied, and the ERP components (P2, N2, and P3) at Fz lead while identifying old pictures (learned) and new ones (unlearned) were measured and compared between the two groups.

RESULTS

While identifying the old pictures, the enuresis group had a lower amplitude of P2 and N2 than the control group (P<0.05). There were no significant differences between the two groups in the latency of P2, N2, and P3 and the amplitude of P3. While identifying the new pictures, the enuresis group had a longer latency of P2 and a significantly lower amplitude of N2 than the control group (P<0.05). There were no significant differences between the two groups in the amplitude of P2 and P3 and the latency of N2 and P3.

CONCLUSIONS

Compared with normal children, the children with primary nocturnal enuresis have reduced abilities of classified information extraction, a prolonged reaction time, and reductions in memory capacity, memory consolidation, and conflict monitoring, which causes working memory impairment.

Cerebellar α6 -subunit-containing GABAA receptors: a novel therapeutic target for disrupted prepulse inhibition in neuropsychiatric disorders

BACKGROUND AND PURPOSE

The pathophysiological role of α₆ -subunit-containing GABA_A receptors, which are mainly expressed in cerebellar granule cells, remains unclear. Recently, we demonstrated that hispidulin, a flavonoid isolated from a local herb that remitted a patient's intractable motor tics, attenuated methamphetamine-induced hyperlocomotion in mice as a positive allosteric modulator (PAM) of cerebellar α₆ GABA_A receptors. Here, using hispidulin and a selective α₆ GABA_A receptor PAM, the pyrazoloquinolinone Compound 6, we revealed an unprecedented role of cerebellar α₆ GABA_A receptors in disrupted prepulse inhibition of the startle response (PPI), which reflects sensorimotor gating deficits manifested in several neuropsychiatric disorders.

EXPERIMENTAL APPROACH

PPI disruptions were induced by methamphetamine and NMDA receptor antagonists in mice. Effects of the tested compounds were measured in Xenopus oocytes expressing recombinant α₆ β₃ γ_2S GABA_A receptors.

KEY RESULTS

Hispidulin given i.p. or by bilateral intracerebellar (i.cb.) injection rescued PPI disruptions induced by methamphetamine, ketamine, MK-801 and phencyclidine. Intracerebellar effects of hispidulin were mimicked by Ro15-4513 and loreclezole (two α₆ GABA_A receptor PAMs), but not by diazepam (an α₆ GABA_A receptor-inactive benzodiazepine) and were antagonized by furosemide (i.cb.), an α₆ GABA_A receptor antagonist. Importantly, Compound 6 (i.p.) also rescued methamphetamine-induced PPI disruption, an effect prevented by furosemide (i.cb.). Both hispidulin and Compound 6 potentiated α₆ β₃ γ_2S GABA_A receptor-mediated GABA currents.

CONCLUSIONS AND IMPLICATIONS

Positive allosteric modulation of cerebellar α₆ GABA_A receptors rescued disrupted PPI by attenuating granule cell activity. α₆ GABA_A receptor-selective PAMs are potential medicines for treating sensorimotor gating deficits in neuropsychiatric disorders. A mechanistic hypothesis is based on evidence for cerebellar contributions to cognitive functioning including sensorimotor gating.

Medical Comorbidity of Attention-Deficit/Hyperactivity Disorder in US Adolescents

Understanding patterns of medical comorbidity in attention-deficit/hyperactivity disorder (ADHD) may lead to better treatment of affected individuals as well as aid in etiologic study of disease. This article provides the first systematic evaluation on the medical comorbidity of ADHD in a nationally representative sample (National Comorbidity Replication Survey-Adolescent Supplement; N = 6483) using formal diagnostic criteria. Survey-weighted odds ratios adjusted for demographics, additional medical, and mental disorders were calculated for associations between ADHD and medical conditions. Models adjusted for demographics revealed significantly increased odds of allergy, asthma, enuresis, headache/migraine, and serious stomach or bowel problems. After adjusting for comorbidity, across the medical conditions, enuresis and serious stomach problems were the strongest correlates of ADHD. These findings confirm the pervasive medical comorbidity of ADHD reported in previous clinical and community-based studies. The intriguing salience of enuresis and serious stomach or bowel conditions may also provide an important clue to multisystem involvement in ADHD.

Enuresis and Hyperactivity-Inattention in Early Adolescence: Findings from a Population-Based Survey in Tokyo (Tokyo Early Adolescence Survey)

BACKGROUND

Enuresis (9% at age 9.5) negatively affects children's psychosocial status. Clinically-diagnosed enuresis (2% at the age) is associated with hyperactivity-inattention, and common neural bases have been postulated to underlie this association. It is, however, unclear whether this association is applicable to enuresis overall among the general population of early adolescents when considered comorbid behavioral problems. We aimed to examine whether enuresis correlates with hyperactivity-inattention after controlling for the effects of other behavioral problems.

METHODS

Participants were 4,478 children (mean age 10.2 ± 0.3 years old) and their parents from the Tokyo Early Adolescence Survey (T-EAS), a population-representative cross-sectional study conducted in Tokyo, Japan conducted from 2012 to 2015. Children's enuresis and behavioral problems, including hyperactivity-inattention (as measured by the Strength and Difficulties Questionnaire), were examined using parent-reporting questionnaires. Multivariate linear regression was used to explore whether enuresis predicts hyperactivity-inattention.

RESULTS

The hyperactivity-inattention score was significantly higher in the enuretic group than the non-enuretic group (enuretic: M (SD) = 3.8 (2.3), non-enuretic: M (SD) = 3.0 (2.1), Hedge's g = 0.39, p < .001). This association remained significant even after controlling for other behavioral problems and including sex, age, intelligence quotient (IQ), low birth weight and parents' education (β = .054 [95% CI: .028-.080], p < .001).

CONCLUSIONS

Enuresis was independently associated with hyperactivity-inattention in early adolescents among general population even when other behavioral problems were considered. These results suggest that, as with clinically-diagnosed cases, enuresis may predict need for screening and psychosocial support for hyperactivity-inattention.

Abnormal Neural Responses to Emotional Stimuli but Not Go/NoGo and Stroop Tasks in Adults with a History of Childhood Nocturnal Enuresis

Background

Nocturnal enuresis (NE) is a common disorder in school-aged children. Previous studies have reported that children with NE exhibit structural, functional and neurochemical abnormalities in the brain, suggesting that children with NE may have cognitive problems. Additionally, children with NE have been shown to process emotions differently from control children. In fact, most cases of NE resolve with age. However, adults who had experienced NE during childhood may still have potential cognitive or emotion problems, and this possibility has not been thoroughly investigated.

Methodology/Principal Findings

In this work, we used functional magnetic resonance imaging (fMRI) to evaluate brain functional changes in adults with a history of NE. Two groups, consisting of 21 adults with NE and 21 healthy controls, were scanned using fMRI. We did not observe a significant abnormality in activation during the Go/NoGo and Stroop tasks in adults with a history of NE compared with the control group. However, compared to healthy subjects, young adults with a history of NE mainly showed increased activation in the bilateral temporoparietal junctions, bilateral dorsolateral prefrontal cortex, and bilateral anterior cingulate cortex while looking at negative vs. neutral pictures.

Conclusions/Significance

Our results demonstrate that adults with a history of childhood NE have no obvious deficit in response inhibition or cognitive control but showed abnormal neural responses to emotional stimuli.

Task positive and default mode networks during a working memory in children with primary monosymptomatic nocturnal enuresis and healthy controls

BACKGROUND

Nocturnal enuresis is a common developmental disorder in children, and primary monosymptomatic nocturnal enuresis (PMNE) is the dominant subtype.

METHODS

This study investigated brain functional abnormalities that are specifically related to working memory in children with PMNE using function magnetic resonance imaging (fMRI) in combination with an n-back task. Twenty children with PMNE and 20 healthy children, group-matched for age and sex, participated in this experiment.

RESULTS

Several brain regions exhibited reduced activation during the n-back task in children with PMNE, including the right precentral gyrus and the right inferior parietal lobule extending to the postcentral gyrus. Children with PMNE exhibited decreased cerebral activation in the task-positive network, increased task-related cerebral deactivation during a working memory task, and longer response times.

CONCLUSION

Patients exhibited different brain response patterns to different levels of working memory and tended to compensate by greater default mode network deactivation to sustain normal working memory function. Our results suggest that children with PMNE have potential working memory dysfunction.

Connectome-Scale Assessments of Functional Connectivity in Children with Primary Monosymptomatic Nocturnal Enuresis

Primary monosymptomatic nocturnal enuresis (PMNE) is a common developmental disorder in children. Previous literature has suggested that PMNE not only is a micturition disorder but also is characterized by cerebral structure abnormalities and dysfunction. However, the biological mechanisms underlying the disease are not thoroughly understood. Graph theoretical analysis has provided a unique tool to reveal the intrinsic attributes of the connectivity patterns of a complex network from a global perspective. Resting-state fMRI was performed in 20 children with PMNE and 20 healthy controls. Brain networks were constructed by computing Pearson's correlations for blood oxygenation level-dependent temporal fluctuations among the 2 groups, followed by graph-based network analyses. The functional brain networks in the PMNE patients were characterized by a significantly lower clustering coefficient, global and local efficiency, and higher characteristic path length compared with controls. PMNE patients also showed a reduced nodal efficiency in the bilateral calcarine sulcus, bilateral cuneus, bilateral lingual gyri, and right superior temporal gyrus. Our findings suggest that PMNE includes brain network alterations that may affect global communication and integration.

Vitamin B12, folate and iron levels in primary nocturnal enuresis

Objective:

Folate, vitamin B12 and iron are important vitamin and minerals which play role in the development of nervous system. The aim of this study was looking at the presence of folate, vitamin B12 and iron deficiency among patients with Primary nocturnal enuresis (PNE) and possible relation between the delay of central nervous system (CNS) development, PNE and folate, vitamin B12 and iron states.

Methods:

Consecutively applied forty patients with PNE (23 girls and 17 boys) and otherwise normal thirty control subjects (17 girls and 13 boys) were included in the study. Average ages (in range) of PNE and the control group were 9.2(6-12) years and 9.3 (6-12) years accordingly. Age, height, weight, complete blood count, blood vitamin B12, folate, ferritin and iron values of both groups were recorded and compared to each other.

Results:

Average vitamin B12 and folate levels of patients with PNE were significantly and statistically lower compared to those of the control group. Average blood iron of patients with PNE was significantly higher than that of the control group and also average ferritin level of the PNE group was detected to be higher than the control group but this relation was statistically insignificant.

Conclusion:

Primary nocturnal enuresis is related to the delay in CNS maturation so it was thought that low vitamin B12 and folate which were found in patients with PNE may have role in the delay of CNS maturation. Additionally, further studies are needed to investigate the role of vitamin B12 and folate either alone or as combination in treatment of patients with PNE who have low vitamin B12and folate level.

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.

Nocturnal enuresis: A topic review and institution experience

The objective is to provide a review of nocturnal enuresis (NE), including its epidemiology, etiology, pathophysiology, evaluation, and current management. We also set to provide further insight on the treatment of this condition from the experience derived from patients cared for at our tertiary-care institution. NE affects approximately 15% of all children at 5-year-old, affecting boys more frequently than girls. At our large university tertiary pediatric urology center, NE and incontinence, in general, is one the most common chief complaints prompting urologic care. In this review, we examine the condition in detail, highlighting specific goals of the initial evaluation and treatment. We contrast the commonly implemented treatment recommendations, available from the literature with strategies we have found valuable from our extensive experience in treating patients with this disorder. Using current urologic reference textbooks, book chapters, Medline, journal articles and reviews describing the many aspects of NE were reviewed in order to describe NE and the current practices at our institution. Although, this is not a systematic literature review, it includes relevant available research, institutional experience and urological expert opinion and current practices at a tertiary state health facility. The treatment of NE remains a challenge for many pediatricians and pediatric urologists. This likely stems from the multiple possible etiologies of the disorder. We have established a treatment algorithm at our institution, which we have found successful in the majority of our patients. This consists of starting patients on urotherapy, then offering both the enuresis alarm device and medication therapy as first line treatments, and finally adding anticholingerics for combination therapy. Our hope is with further research the treatment of NE will continue to improve.

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.

Brain metabolite alterations in children with primary nocturnal enuresis using proton magnetic resonance spectroscopy

Nocturnal enuresis is a common developmental disorder in children; primary monosymptomatic nocturnal enuresis (PMNE) is the dominant subtype. Previous literature has suggested that the prefrontal cortex and the pons are both involved in micturition control. This study aimed to investigate the metabolic levels of the left prefrontal cortex and the pons in children with PMNE by proton magnetic resonance spectroscopy (1H-MRS). Twenty-five children with PMNE and 25 healthy children took part in our experiments. Magnetic resonance examinations were performed on a Siemens 3T Trio Tim scanner. For each subject, localized 1H-MRS was acquired from the left prefrontal cortex (mainly in brodmann area 9) and the pons with a point-resolved spectroscopy sequence with repetition time 2,000 ms, echo time 30 ms and 64 averages. The LCModel software package was used to analyze the MRS raw data, and two-sample t tests were used to determine significant differences between the two groups. The results revealed a significant reduction in metabolite to total creatine ratios of N-acetylaspartate (NAA/tCr) in the left prefrontal cortex and the pons for children with PMNE compared to healthy children. Our study suggests that metabolism is disturbed in the prefrontal cortex and the pons in children with PMNE, which may be associated with the symptoms of enuresis.

Relationship between arousal response in newborn infants before micturition and bed-wetting from 5 to 7 years of age

We evaluated the relationship between arousal response in newborn infants before micturition and the occurrence of bed-wetting from 5 to 7 years of age. This study found that neonates without an arousal response before micturition showed a high probability of bed-wetting in early childhood.

Intensive playing leads to non-monosymptomatic enuresis in children with low prepulse inhibition

AIM

Parents of children suffering from non-monosymptomatic enuresis (nmE) report their child wetting itself during intensive playing. As children with enuresis are characterized by reduced bladder control (measured as prepulse inhibition (PPI) of startle reflex), the hypothesis suggests that intensive playing leads to further decrease in control and consecutive wetting. Two questions are important: Does PPI change while concentrating? Is this difference more explicit in children with daytime incontinence?

METHODS

Forty-four healthy children, 40 children with nmE and 37 with monosymptomatic enuresis (mE) were examined. PPI was measured while watching DVD and while playing Nintendo's Wii(®) , and calculated as percentage of the native startle response.

RESULTS

All probands showed a relevant decrease in PPI: in relaxed state, the PPI of the controls was 54%; when concentrating, it fell to 34.5% (p = 0.014). The decrease in PPI in mE was from 66% to 51% (p = 0.008), and the decrease in PPI in nmE was from 29% to 21% (p = 0.125).

CONCLUSION

While the decrease in PPI when playing was smallest in the group with nmE, overall PPI level was by far the lowest. The findings confirm the aetiology of enuresis through impaired 'sensori-motor gating' in children with nmE and provide a neurophysiologic correlate for wetting while playing.

Changes in the brain microstructure of children with primary monosymptomatic nocturnal enuresis: a diffusion tensor imaging study

BACKGROUND

Primary monosymptomatic nocturnal enuresis (PMNE) is a common disorder in school-aged children. Previous studies have suggested that a developmental delay might play a role in the pathology of children with PMNE. However, microstructural abnormalities in the brains of these children have not been thoroughly investigated.

METHODOLOGY/PRINCIPAL FINDINGS

In this work, we evaluated structural changes in the brains of children with PMNE using diffusion tensor imaging (DTI). Two groups consisting of 26 children with PMNE and 26 healthy controls were scanned using magnetic resonance DTI. The diffusion parameters of fractional anisotropy (FA) and mean diffusivity (MD) were subjected to whole-brain, voxel-wise group comparisons using statistical parametric mapping (SPM). When compared to healthy subjects, children with PMNE showed both a decrease in FA and an increase in MD in the thalamus. MD also increased in the frontal lobe, the anterior cingulate cortex and the insula; these areas are all involved in controlling micturition. The significant changes seen in the thalamus could affect both urine storage and arousal from sleep.

CONCLUSIONS/SIGNIFICANCE

The microstructure abnormalities were observed in the thalamus, the medial frontal gyrus, the anterior cingulate cortex and the insula, which are involved in micturition control network. This indicates developmental delay in these areas may be the cause of PMNE.

Central nervous system processing of emotions in children with faecal incontinence

AIM

Faecal incontinence (FI) is a common disorder involving both the enteric (ENS) and central nervous systems (CNS). The aim of the study is to analyze neurophysiologically the central processing of emotions in children with FI, healthy controls and children with Attention-deficit hyperactivity disorder (ADHD).

METHODS

Fourteen children with FI and constipation, nine with non-retentive FI, 15 controls and 13 children with ADHD were examined. The methods included a physical exam, sonography, Child Behavior Checklist, a psychiatric interview and intelligence test. Acoustic evoked potentials were recorded according to standardized methodology. For the event-related potentials, 80 neutral, 40 positive and 40 negative pictures from the International Affective Picture System (IAPS), and 40 pictures depicting faeces were presented.

RESULTS

Children with FI had significantly more intense responses for most stimuli over the frontal, central and parietal regions compared to controls. Stool pictures did not evoke stronger responses than other stimuli. Children with constipation elicited stronger responses. Children with ADHD did not differ from controls. Acoustic evoked potentials were comparable in all groups.

CONCLUSIONS

Children with FI have increased responses in the processing of emotions. These can be interpreted as a neurobiological vulnerability, possibly due to the association of the ENS and CNS.

Spontaneous brain activity changes in children with primary monosymptomatic nocturnal enuresis: a resting-state fMRI study

Primary monosymptomatic nocturnal enuresis (PMNE) is a common disorder in school-aged children. However, little is known about resting-state neural function in individuals with PMNE. In this work, resting-state functional magnetic resonance imaging (fMRI) was used to investigate changes in spontaneous brain activity in children with PMNE. We analyzed resting-state fMRI data using statistical parametric mapping (SPM) and a resting-state fMRI data analysis toolkit (REST). Regional homogeneity (ReHo) and amplitude of low-frequency fluctuation (ALFF) values were calculated to analyze spontaneous brain activity in 16 children with PMNE and 16 healthy controls. Children with PMNE exhibited significant differences in ALFF or ReHo in the left inferior frontal gyrus, medial frontal gyrus (Brodmann area, BA 10), and left midbrain. Abnormalities in BA 10 and the inferior frontal gyrus may affect children's decision-making with regard to voiding; abnormalities in the midbrain in PMNE children may influence the internal signal transmission in their bladder control network. Our data indicate that, in children with PMNE, several brain areas related to the micturate control network undergo developmental delay.

Altered brain activation during response inhibition in children with primary nocturnal enuresis: an fMRI study

Nocturnal enuresis is a common developmental disorder in children, and primary nocturnal enuresis (PNE) is the dominant subtype. The main purpose of this study was to investigate brain functional abnormalities specifically related to motor response inhibition in children with PNE using fMRI in combination with a Go/NoGo task. Twenty-two children with PNE and 22 healthy children, group-matched for age and sex, took part in this experiment. Although no significant between-group differences in task performance accuracy were observed, PNE patients showed significantly longer response times on average. There were several brain regions with reduced activation during motor response inhibition in children with PNE: the bilateral inferior frontal gyri, right superior and middle frontal gyri, right inferior parietal lobe, bilateral cingulate gyri and insula. Our data indicate that response inhibition in children with PNE is associated with a relative lack of or delay in the maturation of prefrontal cortex circuitry that is known to suppress inappropriate responses. This result might give clues to understanding the pathophysiology of PNE.

Prepulse inhibition of the startle reflex for differentiation of enuresis in children

Children with enuresis can be classified into those who wet their beds only at night (monosymptomatic enuresis, mE), and those who additionally suffer from daytime symptoms, such as urgency or incontinence (non-monosymptomatic enuresis, nmE). Evidence is growing that enuresis may have a central origin: bedwetting children have lower brainstem reflex control (impaired prepulse inhibition) than normal controls. However, findings on this subject are inconsistent. To date, there has been no study in pediatric patients according to the type of enuresis. With the aim of determining whether mE and nmE children differ in terms of central reflex control, we divided 30 enuretic children into two groups (mE and nmE) based on data recorded in a bladder diary and clinical history (19 with history of diurnal urge, 11 without; age 5-14 years). Prepulse inhibition (PPI) of the startle reflex of the children was measured and compared between groups. A significant difference in PPI was observed between the groups, with the nmE group having a lower median PPI level than the mE group (10 vs. 73%, respectively; p = 0.0002). These findings lead to the assumption that a loss of central control plays a role only in the etiology of nmE. Moreover, they may throw a new light on the classification of enuresis.

Rs 6313 polymorphism in 5-hydroxytryptamine receptor 2A gene association with polysymptomatic primary nocturnal enuresis

BACKGROUND

Tricyclic antidepressants (TCA) were used to treat nocturnal enuresis (NE) for decades of years although their real mechanisms are unknown. Recently, some case studies demonstrated the efficacy of selective serotonin reuptake inhibitors (SSRI) in the treatment of NE. Both TCA and SSRI have similar influences on serotonin transmission. This study was aimed at evaluating whether 5-hydroxytryptamine receptor 2A (5HTR2A) gene is associated with NE.

METHODS

We analyzed rs6313 polymorphism in 5HTR2A gene of 213 Taiwanese children (116 NE cases and 97 healthy control subjects) using polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

There were no significant differences when comparing the genotypes and allelic frequencies of rs6313 polymorphism in 5HTR2A gene between patients with NE and control subjects. However, when subsequently comparing 5HTR2A genotypes and allelic frequencies in NE child with different phenotypes, genotypes TT and TC appeared higher risks of polysymptomatic NE compared with CC (odds ratio (OR)=10.71, 95% confidence interval (CI)=2.66-43.12; OR=2.68, 95% CI=0.67-10.75, respectively; P=0.0002); and allele T also revealed higher frequencies of polysymptomatic NE compared with allele C (OR=3.7, 95% CI=2.01-6.79, P=0.000015).

CONCLUSIONS

This is the first study that shows the association between 5HTR2A gene polymorphisms and polysymptomatic NE. These results provide further evidence suggesting that genetic variations at 5HTR2A may influence NE treatment response.

Effects of desmopressin on the sleep of children suffering from enuresis

AIM

To evaluate the effect of 1-desamino-8-D-Arginine Vasopressin (DDAVP) on sleep architecture and arousal reactions in children with primary monosymptomatic nocturnal enuresis (PME).

METHODS

A prospective, placebo-controlled, randomized, double-blind, cross-over study was performed on children suffering from bed-wetting. Placebo and DDAVP were given for 7 days each after which an unattended home polysomnography (PSG) was recorded. After lifting the blinding, the PSGs were compared.

RESULTS

A total of 20 children with PME, aged 6-15 years, were enrolled in the study. The number of wet nights decreased significantly with DDAVP treatment. Delta power, distribution of sleep stages, number of arousals, arousal index and the effect of arousals on sleep stages did not differ significantly. Bed-wetting occurred within each sleep stage and did not follow any particular pattern. In most cases, it was preceded by an arousal reaction, but no awakening occurred.

CONCLUSION

DDAVP has no effect on the sleep architecture of children with PME when analysed by classical PSG, which is determined by collecting the electric activity of cortical neurons. Taking recent research findings into account, this supports the thesis that the disturbances causing PME occur at brain stem level and do not reach consciousness.

Neuroendocrine response to supine posture in healthy children and patients with nocturnal enuresis

OBJECTIVE

To elucidate the background behind the attenuated circadian rhythm of vasoactive hormones in patients with nocturnal enuresis, we tested the hypothesis that enuretic children exhibit an abnormal neuroendocrine response to a baroreflex stimulus during daytime.

DESIGN AND PATIENTS

In fifteen children and adolescents (aged 13.4 +/- 0.9 years) with severe nocturnal enuresis and 10 age- and sex-matched healthy controls, we performed a 'daytime supine posture' (DSP) study at 10:00 h.

MEASUREMENTS

Blood was sampled for measurements of plasma vasopressin (P(AVP)), angiotensin II (P(ANGII)), atrial natriuretic peptide (P(ANP)) and serum aldosterone (S(ALDO)), and mean arterial blood pressure (MAP) and heart rate (HR) were measured during the study.

RESULTS

In both controls and patients with enuresis, DSP at 10:00 h resulted in a marked fall in MAP and HR, a rise in pulse pressure (PP) and estimated plasma volume (PV) and a significant suppression of P(AVP), P(ANGII) and S(ALDO), whereas P(ANP) increased. There were no significant differences between groups in haemodynamic or neuroendocrine responses to DSP.

CONCLUSIONS

The study showed that children with nocturnal enuresis exhibit a normal neuroendocrine response to supine posture during daytime indicating that baroregulatory mechanisms per se are not playing a significant pathogenic role. Interestingly, the normal neuroendocrine response to supine posture seems to undergo marked circadian changes, as supine posture at night-time is associated with increased levels of vasoactive hormones.

Parasomnias in childhood

Common childhood parasomnias, including those occurring at sleep onset and during rapid eye movement sleep or non-rapid eye movement sleep and their ontogeny are discussed. The events may be distressing to both the patient and family members. Stereotypic movements characteristic of some parasomnias most likely arise from disinhibition of subcortical central pattern generators. Genetic predisposition, an inherent instability of non-rapid eye movement sleep and underlying sleep disturbances such as obstructive sleep apnea may predispose to the activation of confusional arousals, sleep walking or sleep terrors. Many parasomnias can be recognized by history alone, but some require nocturnal polysomnography for appropriate diagnosis and management. A scheme to distinguish non-rapid eye movement sleep parasomnias from nocturnal seizures is provided. Behavioral therapy has a role in the management of many childhood parasomnias, but evidence based recommendations are as yet unavailable.

Parasomnias of childhood

PURPOSE OF REVIEW

To enhance the ability of the practitioner to diagnose and manage children with parasomnias in the office setting.

RECENT FINDINGS

Over 80% of preschool-age children experience parasomnia events. Instability in the regulation of sleep continuity might underlie sleep walking, sleep terrors, and confusional arousals. Catathernia or nocturnal groaning is a parasomnia that is recognized in adults but frequently has onset during childhood.

SUMMARY

Common childhood parasomnias such as hypnic starts, rhythmic movement disorder, sleep paralysis, confusional arousals, sleepwalking, sleep terrors, enuresis, and nightmares are discussed. These events may lead to significant concern and worry for the parents. Most parasomnias are recognizable by history alone, but some may require nocturnal polysomnography for accurate diagnosis and determining an underlying trigger factor. Findings on nocturnal polysomnography are described. Sleep terrors, confusional arousals and sleepwalking may mimic seizures; distinguishing seizures from parasomnias is discussed. There is a genetic predisposition to many childhood parasomnias. Management techniques, including behavioral therapy, are reviewed. Unfortunately, evidence-based recommendations are as yet unavailable. The management of sleep enuresis continues to remain a significant challenge.

The impact of maturation of brainstem inhibition on enuresis: a startle eye blink modification study with 2-year followup

PURPOSE

Previous research reveals that children with enuresis show reduced prepulse inhibition, which is supposed to reflect dysfunction in a brainstem nucleus involved in the voiding circuitry cyclus. The main aim of this study was to investigate whether maturation of the brainstem, indexed by a marked increase in percent prepulse inhibition during a period of 2 years, co-occurs with children becoming dry at night.

MATERIALS AND METHODS

Electromyography recorded startle eye blink during modified Ornitz automatic attention task was used to measure brainstem function. For this followup study we randomly contacted 60 children with enuresis (30 with and 30 without attention deficit-hyperactivity disorder) and 25 normally developing controls from a baseline sample. Performance at baseline and at 2-year followup in 25 children with enuresis and attention deficit-hyperactivity disorder and 24 children with enuresis without attention deficit-hyperactivity disorder was compared to 25 controls.

RESULTS

At short lead intervals a significant difference between enuresis groups and the control group was found at baseline, whereas no significant differences were found at 2-year followup. In the enuresis groups there was a significant increase in percent prepulse inhibition between baseline and 2-year followup. Percent prepulse inhibition increase did not differ between children with different 2-year followup enuresis status, or baseline incontinence or attention deficit-hyperactivity disorder symptoms.

CONCLUSIONS

Brainstem maturation was detected in children with enuresis but was not associated with children becoming dry. Patients with and without enuresis at followup did not demonstrate a significant difference in percent prepulse inhibition increase. These data suggest that immaturity of the brainstem may be a mechanism involved in the pathogenesis of enuresis but not in its persistence.

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.

Relief of Nocturnal Enuresis by Desmopressin Is Kidney and Vasopressin Type 2 Receptor Independent

Primary nocturnal enuresis (PNE) is a common problem in childhood and adolescence. Although various treatments are highly effective, a common underlying hypothesis on the pathogenesis is lacking. The success of desmopressin, a synthetic analogue of the antidiuretic hormone vasopressin, has been attributed to increased renal water reabsorption that is mediated by activation of the renal vasopressin V2 receptor (V2R). However, this effect does not explain other symptoms of PNE, such as the failure to arouse upon bladder distension. This study identified a family in which one child displayed PNE and coexisting nephrogenic diabetes insipidus, as a result of a novel nonsense mutation in the V2R gene (C358X). Cell-biologic investigations revealed that V2R-C358X is retained in the endoplasmic reticulum and is unstable, which explains his nephrogenic diabetes insipidus. Consistently, extrarenal V2R-mediated responses were absent in the patient who was treated with desmopressin. Administration of desmopressin, however, changed his PNE into nocturia, because he now still voided unchanged high urinary volumes at night but woke up and went to the bathroom. Withdrawal of desmopressin was accompanied by bedwetting, whereas reintroduction again relieved the symptoms. Therefore, these data indicate that neither a functioning renal concentration system nor a functional V2R is needed for the therapeutic benefit of desmopressin in PNE. Rather, it suggests that another vasopressin receptor and other organ(s) is the target for desmopressin to relieve PNE.

Brainstem auditory evoked response in neonatal neurology

Over the last three decades, the brainstem auditory evoked response (BAER) has been used to assess functional integrity and development of the auditory system and the brain in conditions that affect the brainstem auditory pathway. As a non-invasive objective test, BAER is particularly suitable in very young or sick infants. It is the major tool to detect hearing impairment in high-risk infants, and a component in universal hearing screening. BAER is also a valuable adjunct to detect neurological impairment in many developmental disorders and functional abnormalities in a range of neurological diseases. The maximum length sequence (MLS) technique has recently been incorporated into neonatal BAER study. Recent results indicate that the MLS has the potential to improve the diagnostic value of BAER in some clinical situations, although the wider utility of this relative new technique remains to be further explored.