Aberrant Whole-Brain Functional Connectivity and Intelligence Structure in Children with Primary Nocturnal Enuresis

Aim

To assess the potential relationship between intelligence structure abnormalities and whole-brain functional connectivity in children with primary nocturnal enuresis (PNE) with resting-state functional magnetic resonance imaging (fMRI) to provide insights into the association between these two seemingly unrelated conditions.

Methods

Intelligence testing and fMRI data were obtained from 133 right-handed children, including 67 PNE children (M/F, 39∶28; age, 10.5±1.2 y) and 66 age-matched healthy controls (M/F, 37∶29; age, 10.1±1.1 y). All intelligence tests were performed using the China-Wechsler Intelligence Scale for Children (C-WISC). Each subject’s full intelligence quotient (FIQ), verbal IQ (VIQ), performance IQ (PIQ), and memory/caution (M/C) factor was measured and recorded. Resting state fMRI scans were performed on a 3.0-T MR scanner and post-processed using REST software. Comparisons of z-score correlation coefficients between distinct cerebral regions were used to identify altered functional connectivity in PNE children.

Results

The PNE group had normal FIQ, VIQ, and PIQ values, indicating no significant variation from the control group. However, the M/C factor was significantly lower in the PNE group. Compared to the control group, PNE children exhibited overall lower levels of functional connectivity that were most apparent in the cerebello-thalamo-frontal pathway. The M/C factor significantly correlated with z-scores representing connectivity between Cerebellum_Crus1_L and Frontal_Mid_R.

Conclusion

PNE children exhibit intelligence structure imbalance and attention deficits. Our findings suggest that cerebello-thalamo-frontal circuit abnormalities are likely to be involved in the onset and progression of attention impairment in PNE children.     

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.     

Nocturnal Enuresis: Comparison of the Effect of Imipramine and Dietary Restriction on Bladder Capacity

Fifty children with nocturnal enuresis have been studied with a view to determining maximum bladder capacities and frequency of micturition, and the changes induced by dietary treatment and imipramine. Of 50 children treated with imipramine, 31 were symptomatically cured. Fifteen of the 48 children treated by dietary measures were also symptomatically cured, but as nine had already been cured by imipramine the correct cure rate for dietary treatment, for reasons indicated in the text, may have been no more than seven of the 48 cases. Treatment on the above lines, in those who responded, led to an increase in bladder capacity and a fall in diurnal frequency of micturition.Because the bladder can enlarge under the above conditions it is concluded that the bladder in the average enuretic is functionally but not structurally small, and that when dietary manipulation helps, it does so by eliminating factors from the diet to which the bladder is sensitive. Imipramine, by contrast, is effective because it blocks peripherally this effect.     

Enuresis

Enuresis is a symptom rather than a disease. It may occasionally be the result of an organic condition but most cases are functional in origin. The organic cases are rather simply classified, the diagnosis should not be difficult, and the treatment is fairly well standardized. The functional cases, on the other hand, are of a variety of types which tax the physician and the family in understanding and treating the problem.The author presents some of the known facts about enuresis and discusses the accepted forms of therapy. An important requirement is a better understanding and study of the child from the medical, psychological and environmental viewpoint. In this way a more rational therapy may be advised.