Pathogenesis and brain functional imaging in nocturnal enuresis: A review

Abstract

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.

Bibliometric and visual analysis of nocturnal enuresis from 1982 to 2022

“…In addition, these potential causes of morbidity, such as bladder, vasopressin, and sleep, are also shown on the top 20 keyword lists. These factors have been widely reported (6,47). At present, there are two theories about bladder function derangements.…”

“…Epidemiological studies have shown that the prevalence of NE varies across regions, but the global overall prevalence ranges from 4 to 16% (3,4). Nearly 15% of children with mild symptoms recover on their own each year without any intervention (5), but 1-2% of children with severe conditions will continue to experience symptoms into adulthood (6). Moreover, severe NE can lead to troublesome problems such as psychosocial issues, low self-esteem, fear of sleepovers, and social isolation (7,8); it is also difficult for the families affected.…”

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

“…(2) slice-timing to correct the remaining time points; (3) realignment; (4) normalizing to Montreal Neurological Institute (MNI) template as well as resampling into a new 3 × 3 × 3 mm 3 voxel size by using T1 image unified segmentation; (5) smoothing with a Gaussian kernel (full-width-half-maximum, FWHM of 6 mm); (6) detrending; (7) regressing common covariates out, including Friston's 24 head motion parameters (32), white matter (WM), and cerebrospinal fluid (CSF) signals; (8) filtering (0.01-0.08 Hz). There were 3 children with PNE and 4 HCs excluded for excessive head motion (translation > 2 mm, rotation > 2 • ).…”

“…It is generally believed that nocturnal polyuria, arousal dysfunction, and abnormal nocturnal bladder function are three main factors implicated in the pathogenesis of PNE (4)(5)(6), and maturational delays of the central nervous system have been considered to be related to the pathogenesis of PNE (7). Over the past few decades, magnetic resonance imaging (MRI) technology, especially functional MRI (fMRI), has been validated as an efficient, non-invasive, and promising approach to investigating the neural mechanisms of bladder control in healthy and pathological participants (8).…”

“…Over the past few decades, magnetic resonance imaging (MRI) technology, especially functional MRI (fMRI), has been validated as an efficient, non-invasive, and promising approach to investigating the neural mechanisms of bladder control in healthy and pathological participants ( 8 ). In recent years, brain MRI studies have shown that PNE is strongly linked to alterations in brain structure and function ( 7 ). Our previous resting-state fMRI study has found that spontaneous activity abnormalities of the prefrontal cortex (PFC) and midbrain are likely linked to micturition control impairment in children with PNE ( 9 ).…”