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

Examination of posture and balance in children with primary monosymptomatic nocturnal enuresis

PURPOSE

This study aimed to examine symptom severity, posture, and balance of children with primary monosymptomatic nocturnal enuresis (PMNE) and compare to a healthy control group.

METHODS

Thirty-five children with PMNE and 34 healthy children were included in this study. Physical and sociodemographic characteristics of the children were recorded. Symptom severity was assessed with a Vancouver Non-Neurogenic Lower Urinary Tract Dysfunction/Dysfunctional Elimination Syndrome Questionnaire (NLUTD/DES), a four-day bladder diary and a seven-day bowel diary. Standing postural alignment was assessed with the Spinal Mouse device, and the sensory integration of static balance and dynamic standing balance was assessed with the Biodex Balance System SD.

RESULTS

Compared to healthy controls, children with PMNE demonstrated increased symptom severity (p = 0.001), increased upright lumbar lordosis (p = 0.018) and sacral-hip angles (p = 0.029), decreased static balance in the sensory condition of unstable surface with eyes closed (p = 0.001), and decreased mediolateral dynamic balance (p = 0.049).

CONCLUSION

Children with PMNE demonstrate altered postural alignment, static and dynamic postural instability, and greater symptom severity on the Vancouver NLUTD/DES than age-matched controls.

Altered resting-state functional connectivity of insula in children with primary nocturnal enuresis

Objective

Primary nocturnal enuresis (PNE) is a common developmental condition in school-aged children. The objective is to better understand the pathophysiology of PNE by using insula-centered resting-state functional connectivity (rsFC).

Methods

We recruited 66 right-handed participants in our analysis, 33 with PNE and 33 healthy control (HC) children without enuresis matched for gender and age. Functional and structural MRI data were obtained from all the children. Seed-based rsFC was used to examine differences in insular functional connectivity between the PNE and HC groups. Correlation analyses were carried out to explore the relationship between abnormal insula-centered functional connectivity and clinical characteristics in the PNE group.

Results

Compared with HC children, the children with PNE demonstrated decreased left and right insular rsFC with the right medial superior frontal gyrus (SFG). In addition, the bilateral dorsal anterior insula (dAI) seeds also indicated the reduced rsFC with right medial SFG. Furthermore, the right posterior insula (PI) seed showed the weaker rsFC with the right medial SFG, while the left PI seed displayed the weaker rsFC with the right SFG. No statistically significant correlations were detected between aberrant insular rsFC and clinical variables (e.g., micturition desire awakening, bed-wetting frequency, and bladder volume) in results without global signal regression (GSR) in the PNE group. However, before and after setting age as a covariate, significant and positive correlations between bladder volume and the rsFC of the left dAI with right medial SFG and the rsFC of the right PI with right medial SFG were found in results with GSR in the PNE group.

Conclusion

To the best of our knowledge, this study explored the rsFC patterns of the insula in children with PNE for the first time. These results uncovered the abnormal rsFC of the insula with the medial prefrontal cortex without and with GSR in the PNE group, suggesting that dysconnectivity of the salience network (SN)-default mode network (DMN) may involve in the underlying pathophysiology of children with PNE. However, the inconsistent associations between bladder volume and dysconnectivity of the SN-DMN in results without and with GSR need further studies.

Abnormal resting-state functional connectivity of hippocampal subregions in children with primary nocturnal enuresis

OBJECTIVE

Previous neuroimaging studies have shown abnormal brain-bladder control network in children with primary nocturnal enuresis (PNE). The hippocampus, which has long been considered to be an important nerve center for memory and emotion, has also been confirmed to be activating during micturition in several human imaging studies. However, few studies have explored hippocampus-related functional networks of PNE in children. In this study, the whole resting-state functional connectivity (RSFC) of hippocampus was investigated in children with PNE.

METHODS

Functional magnetic resonance imaging data of 30 children with PNE and 29 matched healthy controls (HCs) were analyzed in our study. We used the seed-based RSFC method to evaluate the functional connectivity of hippocampal subregions defined according to the Human Brainnetome Atlas. Correlation analyses were also processed to investigate their relationship with disease duration time, bed-wetting frequency, and bladder volume.

RESULTS

Compared with HCs, children with PNE showed abnormal RSFC of the left rostral hippocampus (rHipp) with right fusiform gyrus, right Rolandic operculum, left inferior parietal lobule, and right precentral gyrus, respectively. Moreover, decreased RSFC of the left caudal hippocampus (cHipp) with right fusiform gyrus and right supplementary motor area was discovered in the PNE group. There were no significant results in the right rHipp and cHipp seeds after multiple comparison corrections. In addition, disease duration time was negatively correlated with RSFC of the left rHipp with right Rolandic operculum (r = -0.386, p = 0.035, uncorrected) and the left cHipp with right fusiform gyrus (r = -0.483, p = 0.007, uncorrected) in the PNE group, respectively. In the Receiver Operating Characteristic (ROC) analysis, all the above results of RSFC achieved significant performance.

CONCLUSIONS

To our knowledge, this is the first attempt to examine the RSFC patterns of hippocampal subregions in children with PNE. These findings indicated that children with PNE have potential dysfunctions in the limbic network, sensorimotor network, default mode network, and frontoparietal network. These networks may become less efficient with disease duration time, inducing impairments in brain-bladder control, cognition, memory, and emotion. Further prospective research with dynamic observation of brain imaging, bladder function, cognition, memory, and emotion is warranted.

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.

Hemodynamics of Prefrontal Cortex in Ornithine Transcarbamylase Deficiency: A Twin Case Study

Ornithine transcarbamylase deficiency (OTCD) is the most common form of urea cycle disorder characterized by the presence of hyperammonemia (HA). In patients with OTCD, HA is known to cause impairments in domains of executive function and working memory. Monitoring OTCD progression and investigating neurocognitive biomarkers can, therefore, become critical in understanding the underlying brain function in a population with OTCD. We used functional near infrared spectroscopy (fNIRS) to examine the hemodynamics of prefrontal cortex (PFC) in a fraternal twin with and without OTCD. fNIRS is a non-invasive and wearable optical technology that can be used to assess cortical hemodynamics in a realistic clinical setting. We quantified the hemodynamic variations in total-hemoglobin as assessed by fNIRS while subjects performed the N-back working memory (WM) task. Our preliminary results showed that the sibling with OTCD had higher variation in a very low frequency band (<0.03 Hz, related to mechanism of cerebral autoregulation) compared to the control sibling. The difference between these variations was not as prominent in the higher frequency band, indicating the possible role of impaired autoregulation and cognitive function due to presence of HA. We further examined the functional connectivity in PFC, where the OTCD sibling showed lower interhemispheric functional connectivity as the task load increased. Our pilot results are the first to show the utility of fNIRS in monitoring OTCD cortical hemodynamics, indicating the possibility of inefficient neurocognitive function. This study provides a novel insight into the monitoring of OTCD focusing on the contribution of physiological process and neurocognitive function in this population.

Amplitude of low-frequency fluctuation of resting-state fMRI in primary nocturnal enuresis and attention deficit hyperactivity disorder

Children with attention deficit hyperactivity disorder (ADHD) and nocturnal enuresis (NE) have similar symptoms, for example, inattention and dysfunction of working memory. We investigate disorder-specific abnormal activity by using the simple resting-state functional magnetic resonance imaging (RS-fMRI) metric amplitude of low-frequency fluctuation (ALFF). About 18 ADHD, NE, and typically developing children were examined by RS-fMRI and the child behavior checklist (CBCL) test. One-way ANOVA were used to compare the ALFF values of the three groups and post hoc was done. We conducted Pearson correlation analysis on the results of the three groups' scales with ALFF values at the discrepant brain areas after then. Significant group effect was found in the bilateral medial prefrontal cortex (MPFC), left inferior temporal gyrus (ITG), left middle temporal gyrus (MTG), cerebellum anterior lobe (CAL), and left inferior parietal lobule (IPL). There was no shared abnormal region for ADHD and NE. Specially, ADHD showed increased ALFF in the bilateral MPFC, left ITG, and CAL and showed decreased ALFF in the left MTG. The children with NE showed increased ALFF in the left IPL. This study reveals the brain mechanism of cognitive changes on ADHD and NE, which provides neuroimaging basis for behavioral differences among different diseases.

Evaluation of neuropsychological development of children diagnosed with primary monosymptomatic nocturnal enuresis: A pilot study

OBJECTIVE

Studies on primary monosymptomatic nocturnal enuresis have supported neuromotor development delay. This study aims to examine the neuropsychological development of children with primary monosymptomatic nocturnal enuresis.

MATERIAL AND METHODS

This study included 30 children diagnosed with primary monosymptomatic nocturnal enuresis and 30 healthy children. Both groups were analyzed by pediatric psychologists using the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the Bender Gestalt Visual Motor Detection test. The WISC-R test is an intelligence test that includes six verbal subscales (information, similarities, arithmetic, vocabulary, judgment, and digit span) and six performance subscales (picture completion, picture arrangement, block design, object assembly, coding, and labyrinths). The Bender Gestalt test is a psychological assessment instrument used to evaluate visuomotor functioning, visuospatial functions, spatial memory, visuomotor integration skills, and visual perception skills.

RESULTS

There were no differences in age (7.66±0.9 versus 8±1.07 years, p>0.05) or sex (20 females versus 20 males, p>0.05) between the groups. Picture completion (p=0.024), picture arrangement (p=0.001), and object assembly test (p=0.000) performance was found to be worse in subjects with primary monosymptomatic nocturnal enuresis. Similarity (p=0.021) and judgment tests (p=0.048) of the verbal subtests were also found to be delayed in the nocturnal enuresis cases.

CONCLUSION

Our results suggest that children with nocturnal enuresis have lower performance compared with the control group in terms of abstract thinking, correct expression of thought, cause-result relation, short-term memory, and problem-solving ability. These children should be routinely tested by neurodevelopment tests and receive support in areas in which they are delayed.

[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.

Morphometric Magnetic Resonance Imaging Study in Children With Primary Monosymptomatic Nocturnal Enuresis

OBJECTIVE

Primary monosymptomatic nocturnal enuresis (PMNE) refers to bed-wetting in children who have no other lower urinary tract symptoms and are never dry for more than 6 months. Our previous studies demonstrated that children with PMNE exhibited brain functional abnormalities compared with healthy controls; however, researches on the abnormalities in gray matter were limited. This study aimed to investigate brain structural changes in gray matter of children with PMNE using magnetic resonance imaging (MRI).

METHODS

Gray matter volumes (GMVs) and gyrification indices (GIs) were calculated using voxel-based and surface-based morphometry analyses of structural MRI data acquired from 26 children with PMNE and 28 healthy children. To identify between-group differences in gray matter, two-sample t-tests were conducted on GMV and GI images separately.

RESULTS

Compared with the controls, children with PMNE showed significantly increased GMVs in the supplementary motor area and medial prefrontal cortex regions (mean GMV in PMNE: 0.54 ± 0.07 l; mean GMV in controls: 0.50 ± 0.06 l) and reduced GIs in the right precuneus (mean GI in PMNE: 25.74° ± 2.34°; mean GI in controls: 27.97° ± 1.79°).

CONCLUSION

Children with PMNE showed abnormal GMVs in frontal lobe and GIs in precuneus, and these changes might be involved in the pathological mechanism of PMNE.

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.