Recent advances in the treatment of gastrointestinal motility disorders in children.

INTRODUCTION: Pediatric gastrointestinal motility disorders represent some of the most challenging clinical conditions with largely undefined pathogenetic pathways and therefore limited therapeutic options. Herein, we provide an overview of the recent advances in treatment options for these disorders and their clinical impact. AREAS COVERED: PubMed and Medline databases were searched for relevant articles related to the treatment of achalasia, esophageal atresia, gastroparesis, PIPO and constipation published between 2017 and 2022. In this article, we review and summarize recent advances in management of gastrointestinal motility disorders in children with a particular focus on emerging therapies as well as novel diagnostic modalities that help guide their application or develop new, more targeted treatments. EXPERT OPINION: Gastrointestinal motility disorders represent one of the most challenging conundrums in pediatric age and despite significant advances in investigative tools, the palette of treatment options remain limited. Overall, while pharmacological options have failed to bring a curative solution, recent advances in minimal invasive therapeutic and diagnostic techniques have emerged as potential keys to symptom and quality of life improvement, such as ENDOFLIP, POEM, cine-MRI, fecal microbiota transplantation.

Evaluating the molecular and genetic mechanisms underlying gut motility disorders.

INTRODUCTION: Gastrointestinal (GI) motility disorders comprise a wide range of different diseases affecting the structural or functional integrity of the GI neuromusculature. Their clinical presentation and burden of disease depends on the predominant location and extent of gut involvement as well as the component of the gut neuromusculature affected. AREAS COVERED: A comprehensive literature review was conducted using the PubMed and Medline databases to identify articles related to GI motility and functional disorders, published between 2016 and 2023. In this article, we highlight the current knowledge of molecular and genetic mechanisms underlying GI dysmotility, including disorders of gut-brain interaction, which involve both GI motor and sensory disturbance. EXPERT OPINION: Although the pathophysiology and molecular mechanisms underlying many such disorders remain unclear, recent advances in the assessment of intestinal tissue samples, genetic testing with the application of 'omics' technologies and the use of animal models will provide better insights into disease pathogenesis as well as opportunities to improve therapy.

Small Bowel Transit Scintigraphy in Children With Pediatric Intestinal Pseudo-Obstruction.

INTRODUCTION: Objective evidence of small intestinal dysmotility is a key criterion for the diagnosis of pediatric intestinal pseudo-obstruction (PIPO). Small bowel scintigraphy (SBS) allows for objective measurement of small bowel transit (SBT), but limited data are available in children. We aimed to evaluate the utility of SBS in children suspected of gastrointestinal dysmotility. METHODS: Patients undergoing gastric emptying studies for suspected foregut dysmotility, including PIPO, from 2016 to 2022 at 2 tertiary children's hospitals were recruited to an extended protocol of gastric emptying studies to allow for assessment of SBT. PIPO was classified based on antroduodenal manometry (ADM). SBT was compared between PIPO and non-PIPO patients. Scintigraphic parameters were assessed and correlated against ADM scores. RESULTS: Fifty-nine patients (16 PIPO and 43 non-PIPO diagnoses) were included. SBS was performed with liquid and solid meals in 40 and 26 patients, respectively. As compared to the non-PIPO group, PIPO patients had a significantly lower median percentage of colonic filling at 6 hours, with both liquid (48% vs 83%) and solid tests (5% vs 65%). SBT in PIPO patients with myopathic involvement was significantly slower than in patients with neuropathic PIPO, both for liquid and solid meal. A significant correlation was found between solid SBT and ADM scores (r = -0.638, P = 0.036). DISCUSSION: SBS provides a practically feasible assessment of small intestinal motility. It shows a potential utility to help diagnose and characterize PIPO. SBS seems most discriminative in PIPO patients with myopathic involvement. Studies in a larger pediatric population and across different ages are required.

The Potential Role of Microorganisms on Enteric Nervous System Development and Disease.

The enteric nervous system (ENS), the inherent nervous system of the gastrointestinal (GI) tract is a vast nervous system that controls key GI functions, including motility. It functions at a critical interface between the gut luminal contents, including the diverse population of microorganisms deemed the microbiota, as well as the autonomic and central nervous systems. Critical development of this axis of interaction, a key determinant of human health and disease, appears to occur most significantly during early life and childhood, from the pre-natal through to the post-natal period. These factors that enable the ENS to function as a master regulator also make it vulnerable to damage and, in turn, a number of GI motility disorders. Increasing attention is now being paid to the potential of disruption of the microbiota and pathogenic microorganisms in the potential aetiopathogeneis of GI motility disorders in children. This article explores the evidence regarding the relationship between the development and integrity of the ENS and the potential for such factors, notably dysbiosis and pathogenic bacteria, viruses and parasites, to impact upon them in early life.

Pediatric Neurogastroenterology and Motility: Moving Rapidly Into the Future.

The field of pediatric neurogastroenterology and motility encompasses some of the most common and severe gastrointestinal (GI) disorders that affect children. GI motility disorders remain, in general, poorly understood, variably diagnosed, and inadequately treated. Although the field progressed relatively slowly over the last decades, the coming years will, no doubt, see it move into a prolific and dynamic era. With this review, we look forward to this brighter future for the field and highlight emerging areas that show promise and deserve focus in the coming years. This includes the role of early life programming and insult of the enteric neuromusculature as a key determinant of motility diseases and factors that are likely to be relevant in disease etiopathogenesis. We discuss several recent and futuristic developments and advancements in investigative and diagnostic tools as well as novel approaches that have been introduced in the management of GI motility disorders. These include targeted and personalized medicine in both pharmacological and multidisciplinary approaches as well as the emerging therapeutic options such as bioelectrical neuromodulation and regenerative medicine.

Intra- and Inter-observer Agreement of High Resolution Antroduodenal Manometry in Pediatric Patients Among Single Center Experts.

OBJECTIVES: Studies in adults have suggested that high-resolution technology increases the diagnostic yield of antroduodenal manometry (ADM). However, there is no study comparing high-resolution with low-resolution ADM recordings as well as comparing the 2 types of high-resolution display [conventional line plot (CLP) and pressure topographic plots (PTP)]. We hypothesized that high-resolution ADM is a superior diagnostic modality with higher inter-observer and intra-observer agreement compared with low-resolution recordings. METHODS: Twenty-four anonymized ADM studies were blindly analyzed by 3 experienced pediatric neurogastroenterologists. All studies had been performed using a low-compliance water-perfused system with a 20-channels catheter. Data were displayed as CLP, as both high-resolution and low-resolution, and PTP in different sessions with at least 6-week interval. Accuracy was evaluated using previous established diagnosis and specific pre-prandial and post-prandial manometric patterns. Inter-observer and intra-observer agreements were calculated. RESULTS: Analysis with high-resolution CLP revealed a substantial inter-observer agreement among the 3 observers regarding the diagnosis (Krippendorff's alpha: 0.832; average pairwise percentage agreement: 88.9%). Conversely, PTP and low-resolution CLP showed poor agreement for diagnoses (Krippendorff's alpha: 0.600; average pairwise percentage agreement: 75.3%; Krippendorff's alpha: 0.390; average pairwise percentage agreement: 60.2%, respectively). For the intra-observer agreement, Krippendorff's alpha ranges were 0.891-1 for CLP and 0.19393-0.34621 for PTP. CONCLUSIONS: Our study demonstrated higher diagnostic accuracy for high-resolution ADM compared to the low-resolution recordings. However, although it is well established for other motility investigations, PTP is not yet reliable in assessing foregut motor patterns. Advanced and more sophisticated software are clearly required for analyzing PTP display.

Recent advances in understanding the roles of the enteric nervous system.

The enteric nervous system (ENS), the intrinsic innervation of the gastrointestinal (GI) tract, is a vast, mesh-like network of neurons and glia embedded within the bowel wall. Through its complex circuitry and neuronal diversity, the ENS is capable of functioning autonomously but is modulated by inputs from the central nervous system (CNS). The communication between the ENS and CNS is bidirectional and, together with crosstalk of these systems with microbiota housed within the GI tract, underpins the so-called microbiota-gut-brain axis. The ENS functions as a master regulator and coordinates many of the essential functions of the body, including GI motility, sensation and secretion. It is also capable of interacting with other cells, including intestinal epithelial, neuroendocrine and immune cells, to regulate their development as well as structural and functional integrity. Disruption of these ENS interactions, especially during early life, is likely to contribute to the aetiopathogenesis of disorders of the GI tract as well as elsewhere in the body, including neurodegenerative diseases. In this article, we highlight recent advances in our understanding of the roles of the ENS, especially in its complex and reciprocal interactions that influence GI motility, sensation, intestinal epithelial integrity, immunity and neuroendocrine function, particularly focusing on the influence of the ENS in early life and early life programming.

Hirschsprung disease and Paediatric Intestinal Pseudo-obstruction.

Hirschsprung disease (HSCR) and Paediatric Intestinal Pseudo-obstruction (PIPO) comprise two of the most recognized and severe disorders of gastrointestinal (GI) motility. HSCR is a developmental disorder of the enteric nervous system invariably affecting the large intestine, whereas the majority of PIPO conditions represent congenital disorders of one or more components of the neuromusculature and more diffusely affect the GI tract. Histopathology is deemed the gold standard for the diagnosis of HSCR and, arguably, of PIPO, but, other diagnostic modalities such as manometric and genetic studies have seen recent advances that may increase their utility. Especially for PIPO, management is multidisciplinary and best performed in specialist referral centres. Surgery remains the only viable treatment for HSCR and appears essential to optimize and sustain feeding and viability of intestinal function in PIPO patients. Novel therapies such as neural stem cell transplants show promise for the future.

Transpyloric propagation and liquid gastric emptying in children with foregut dysmotility.

BACKGROUND/OBJECTIVES: Gastric emptying (GE) requires precise antropyloroduodenal coordination for effective transpyloric flow, the mechanisms of which are still unclear. We aimed to correlate gastric antral function assessed by antroduodenal manometry (ADM) with GE scintigraphy (GES) for liquid feeds in children with suspected gastrointestinal dysmotility. METHODS: Children who underwent both ADM and GES over a five-year period were reviewed. ADM tracings were re-analyzed to assess antral frequency, amplitude, and motility index (MI) pre-prandially and postprandially. Transpyloric propagation (TPP) was defined as antegrade propagated antral activity preceding duodenal phase III of the migrating motor complex (MMC). TPP was defined as "poor" if occurring in <50% of all presented duodenal phases III. For GES, regions of interest over the whole stomach, fundus, and antrum were drawn to calculate GE half-time (GE-T1/2 ) and retention rate (RR) in each region at 1 and 2 h. RESULTS: Forty-seven children (median age: 7.0 years) were included. Twenty-two had PIPO, 14 functional GI disorders, and 11 gastroparesis. Children with poor TPP had longer GE-T1/2 (113.0 vs 66.5 min, p = 0.028), higher RR of the whole stomach and fundus at 1 h (79.5% vs 63.5%, p = 0.038; 60.0% vs 41.0%, p = 0.022, respectively) and 2 h (51.0% vs 10.5%, p = 0.005; 36.0% vs 6.5%, p = 0.004, respectively). The pre-prandial antral amplitude of contractions inversely correlated with GE-T1/2 , RR of the whole stomach, and fundus at 2 h. CONCLUSIONS: TPP during phase III of the MMC correlated with gastric emptying of liquid and its assessment on ADM might predict abnormalities in postprandial gastric function.

Wilson disease in children and young adults - State of the art.

Wilson disease (WD) is an autosomal recessive disorder caused by mutations of the ATP7B gene, with a reported prevalence of 1:30,000-50,000. ATP7B encodes an enzyme called transmembrane copper-transporting ATPase, which is essential for copper incorporation into ceruloplasmin and for copper excretion into the bile. A lack or dysfunction of this enzyme results in a progressive accumulation of copper in several organs, especially in the liver, the nervous system, corneas, kidneys, and heart. Children with WD can present with asymptomatic liver disease, cirrhosis, or acute liver failure, with or without neurological and psychiatric symptoms. Approximately 20%-30% of WD patients present with ALF, while most of the other patients have chronic progressive hepatitis or cirrhosis if untreated. Although genetic testing has become a more important diagnostic tool for WD, the diagnosis remains based on both clinical features and laboratory investigations. The aims of treatment are to reduce copper levels and prevent its accumulation in the liver and other organs, especially in the central nervous system. Liver transplantation in WD is a life-saving option for patients presenting with liver failure and encephalopathy. For WD patients treated with chelating agents, adherence to the therapy is essential for long-term success. In this review, we also address specific issues in young adults as compared to children.

Re-evaluation of King Wilson Index in Children With Acutely Decompensated Hepatic Wilson Disease.

OBJECTIVES: Liver transplantation (LT) in Wilson disease (WD) is a life-saving option for patients presenting with liver failure and encephalopathy. Patients without encephalopathy can avoid LT and treated successfully with chelation therapy. It is essential to predict the risk of fatal outcomes where LT is required. We aim to critically analyse the validity of the WD Index prospectively from a cohort of WD patients managed at our institution. METHODS: WD Index and other clinical data from 2005 to 2018, recorded prospectively as part of clinical management, were analysed. RESULTS: Over 13-year period, 52 children with WD (29 boys) with median age at diagnosis of 11.69 (range 3.92-17.26) years were studied. Of these, 17 were diagnosed as part of family screening, 17 presented with abnormal liver enzyme, and 18 with acute hepatic decompensation (AHD) as per PALF definition. Patients presented with abnormal liver enzyme and in the pre-symptomatic group had WD Index <11, and none of them required LT. WD Index is still a good predictor for LT in WD patients with AHD, providing a sensitivity of 80%, specificity of 100%, positive-predictive, and negative-predictive value of 100% and 80%, respectively. Patients presented with an index of 8-10 also required LT at median duration of 58 days (IQR 48-135 days). CONCLUSIONS: WD patients presenting with AHD who had an index of ≥11 do require LT. Children with a WD Index of 8 to 10 within the first 2 months of admission require close monitoring as LT may become necessary.

Enhancing the utility of antroduodenal manometry in pediatric intestinal pseudo-obstruction.

BACKGROUND: Antroduodenal manometry (ADM) and histopathology are currently employed to aid the diagnosis of pediatric intestinal pseudo-obstruction (PIPO). Limited data are available on the reliability of ADM analysis and its correlation with histopathology. We aimed to develop a protocol for enhanced analysis of ADM contractile patterns, including a scoring system, and explore whether this provided better correlation with histopathology. METHODS: Children referred with suspected PIPO between April 2012-December 2019 who underwent both ADM and full-thickness biopsies were included. ADM tracings were analyzed using both standard (conventional ADM) and novel (enhanced ADM) motility parameters. A novel ADM score (GLASS score) was generated based on the enhanced ADM analysis. Conventional and enhanced ADM analyses were then correlated with histopathology. RESULTS: Forty patients were included. Using conventional clinical criteria, 29 of these were diagnosed with PIPO and the other 11 with non-PIPO diagnoses. Twenty-three of the PIPO patients had abnormal histopathology: 6 myopathy, 4 neuropathy, 3 neuro-myopathy, and 10 non-specific changes. No agreement in diagnosis was found between conventional ADM analysis and histopathology (Ï° = 0.068; p = 0.197), whereas the latter significantly correlated with enhanced ADM analysis (Ï° = 0.191; p = 0.003). The enhanced ADM score was significantly higher in PIPO versus non-PIPO (16.0 vs. 8.0; p < 0.001). CONCLUSIONS: As opposed to conventional analysis protocols, the newly developed enhanced ADM analysis and associated score is not only able to discriminate between PIPO and non-PIPO patients, but also between distinct histopathological pathologies. Further studies are required to assess the utility of enhanced ADM analysis in larger populations.

Automated computational analysis reveals structural changes in the enteric nervous system of nNOS deficient mice.

Neuronal nitric oxide synthase (nNOS) neurons play a fundamental role in inhibitory neurotransmission, within the enteric nervous system (ENS), and in the establishment of gut motility patterns. Clinically, loss or disruption of nNOS neurons has been shown in a range of enteric neuropathies. However, the effects of nNOS loss on the composition and structure of the ENS remain poorly understood. The aim of this study was to assess the structural and transcriptional consequences of loss of nNOS neurons within the murine ENS. Expression analysis demonstrated compensatory transcriptional upregulation of pan neuronal and inhibitory neuronal subtype targets within the Nos1-/- colon, compared to control C57BL/6J mice. Conventional confocal imaging; combined with novel machine learning approaches, and automated computational analysis, revealed increased interconnectivity within the Nos1-/- ENS, compared to age-matched control mice, with increases in network density, neural projections and neuronal branching. These findings provide the first direct evidence of structural and molecular remodelling of the ENS, upon loss of nNOS signalling. Further, we demonstrate the utility of machine learning approaches, and automated computational image analysis, in revealing previously undetected; yet potentially clinically relevant, changes in ENS structure which could provide improved understanding of pathological mechanisms across a host of enteric neuropathies.

Mental Health, Cognitive, and Neuropsychiatric Needs in Children and Young People With Wilson Disease.

Wilson disease (WD) is associated with neurological, psychiatric, cognitive, and psychosocial difficulties, but there is little data regarding the nature and prevalence of these problems in children and young people (CYP). Methods: A single-center case-note review to establish the incidence and nature of these issues in CYP with WD, managed before and after multidisciplinary team (MDT) clinics, was established. Results: Out of 69 (43 males) CYP with WD, 37.8% presented with acute liver failure, 48.6% with chronic liver disease and 13.5% after family screening. Medical treatment was with penicillamine (40), trientene (18), zinc and penicillamine/trientene (11), and zinc monotherapy (2). Twenty-one underwent liver transplantation. After a median follow-up of 9.8 (IQR 6.4-16.9) years, 86% are alive. Six died posttransplantation and 7 grafts were lost. Mental health difficulties were recorded in 49.3%, particularly prevalent in the acute liver failure group (70.8%). Nonadherence was common (50.7%) and associated with greater mental health prevalence. Neurological issues were reported in 36.2% and poor cognition/attainment in 14.5%, consistent across modes of presentation. Four patients had diagnoses of autism spectrum conditions, all diagnosed pre WD. CYP seen within an MDT-clinic had more frequent documentation of all issues examined, but lower levels of late graft loss (94% versus 80%, P = 0.07). Conclusion: Our data highlight the need to offer management in WD patients especially as these aspects are underrecognized in CYP presenting with liver involvement. We aim to highlight the importance of multidisciplinary input when looking after this population beyond transition through to adult services.

Long-Term Urinary Copper Excretion on Chelation Therapy in Children with Wilson Disease.

OBJECTIVES: In Wilson disease (WD), 24-hour urinary copper excretion (UCE) is recommended to be used for diagnosis. It may be a useful tool to assess the efficacy of treatment during follow-up; however, there are limited data regarding the cutoff value of 24-hour UCE during follow-up in children. Therefore, we aim to evaluate the clinical use of 24-hour UCE during follow-up in children with WD. PATIENTS AND METHODS: Medical records of children diagnosed with WD at Kings' College Hospital from 2005 to 2018 were retrospectively reviewed. The UCE, serum copper, and ceruloplasmin levels, tested during follow-up, were statistically analyzed. RESULTS: Over the median duration of 7 years (range 1.4-14.4), 28 patients (age ranged 3.8-17.3 years) had UCE tests during follow-up. Of those, 21 patients had at least one 24-hour UCE test and 7 children had only spot UCE tests. In comparison with the level of 24-hour UCE collected at the first visit after penicillamine challenge test, the median excretion rate was significantly reduced over the follow-up period (P < 0.001), from 26.2 to 8.9 µmol/day following 1-2 years of therapy (P = 0.15), then reduced significantly to 2.2 µmol/day after 3-4 years (P = 0.009), and 5.6 µmol/day at >5 years of follow-up (P = 0.003). CONCLUSIONS: Our study suggests that within 1 year of treatment, the level of nonceruloplasmin-bound copper concentration (NCC) drops to <0.8 µmol/L. In the absence of progressive liver disease or signs of copper deficiency, 24-hour UCE decreases to ≤8 µmol/day and <6 µmol/day after 1 and 5 years of treatment, respectively.

Late allograft fibrosis in pediatric liver transplant recipients: Assessed by histology and transient elastography.

Late allograft fibrosis in LT recipients can cause graft dysfunction and may result in re-transplantation. TE is a non-invasive tool for the assessment of liver fibrosis. We aimed to evaluate the prevalence of allograft fibrosis in pediatric LT recipients, identify factors associated with allograft fibrosis, and determine the diagnostic value of TE, compared to histology. All children who underwent LT for ≥3 years were included. TE was performed for LSM in all patients. LSM of ≥7.5 kPa was considered as abnormal and suggestive of allograft fibrosis. Percutaneous liver biopsy was performed when patients had abnormal LSM and/or abnormal LFTs. Histological fibrosis was diagnosed when METAVIR score ≥F1 or LAF scores ≥1. TE was performed in 43 patients and 14 (32.5%) had abnormal LSM suggestive of allograft fibrosis. Histological fibrosis was identified in 10 of the 15 patients (66.7%) who underwent percutaneous liver biopsy and associated findings included chronic active HBV infection (n = 3), and late acute rejection (n = 3). Multivariate analysis showed that graft age was significantly associated with allograft fibrosis (OR = 1.22, 95% CI: 1.05-1.41, P = 0.01). In conclusion, late allograft fibrosis is common in children undergoing LT for ≥3 years and associated with graft age. HBV infection and late acute rejection are common associated findings. Abnormal TE and/or LFTs may guide physicians to consider liver biopsy for the detection of late allograft fibrosis in LT children.

Laxative Choice and Treatment Outcomes in Childhood Constipation: Clinical Data in a Longitudinal Retrospective Study.

PURPOSE: Functional constipation (FC) is a common gastrointestinal (GI) problem affecting children's well-being and quality of life. Although polyethylene glycol (PEG) is recommended as the first line therapy, it is not always applicable in lower socioeconomic populations. Hence, this study aimed to compare clinical courses of FC in children treated with different medications in order to identify prognostic factors related to treatment outcomes. METHODS: We reviewed the medical records of patients aged ≤15 years diagnosed with FC according to the Rome IV criteria from 2007 to 2015 at the GI clinic, Songklanagarind Hospital. Baseline characteristic, medical history, and treatment outcomes were collected at first and subsequent visits. RESULTS: Exactly 104 patients (median age at diagnosis, 2.8 years) were diagnosed with FC. The number of follow-up visits per patient ranged from 1 to 35. The median duration of follow-up was 18.0 months (range, 6.0-84.2 months). PEG was given to 21% of patients. During the follow up period, 76% of patients experienced first recovery with a median time to recovery of 9.8 months. There were no significant differences in time until first recovery and relapse between patients who received and those who did not receive PEG (p=0.99 and 0.06, respectively). Age >6 years, normal defecation frequency, no history of cow's milk protein allergy, and use of laxatives were associated with successful outcomes. CONCLUSION: Treatment outcomes between patients who had and never had PEG demonstrated no significant difference in our study. Hence, current practices in laxative prescriptive patterns may be effective.

Declining age of puberty of school girls in southern Thailand.

BACKGROUND: Declines in the onset age of secondary sexual development have been reported in a number of recent studies in western and Asian countries. A study of Hat-Yai school girls in 1994 in Thailand showed that the ages at thelarche and menarche were 9.9 and 12.4 years, respectively. This study was to determine whether there was a decline in the average age of puberty in Hat-Yai school girls from 1994 to 2012. METHODS: A cross-sectional study was conducted in 2140 healthy Hat-Yai school girls, aged 6-18 years, from June 2011 to March 2012. Breast and pubic hair development was assessed by the Tanner staging method. Probit analysis was used to calculate the median ages of different stages of breast and pubic hair development, and the age of menarche. RESULTS: The median ages of girls having thelarche and menarche were 9.6 (95% CI, 9.4-9.8) and 12.2 (95% CI, 11.9-12.4) years, which declined from 9.9 (95% CI, 9.7-10.1) and 12.4 years (95% CI, 12.2-12.6) in the 1994 study respectively, however, without statistical significance. The youngest ages of girls who had breast stage 2 and menarche were 7.2 and 9.2 years, respectively. The final height at age 14 years in this cohort (157.3 cm) was 2.3 cm greater than that of girls in 1994 (155.0 cm). CONCLUSIONS: From 1994 to 2012, the age at onset of thelarche and menarche of girls in Hat-Yai municipality declined by 0.2 and 0.3 years, respectively. The earlier age at onset of puberty had no effect on final adult height.