CCDC88C variants are associated with focal epilepsy and genotype-phenotype correlation

CCDC88C gene, which encodes coiled-coil domain containing 88C, is essential for cell communication during neural development. Variants in the CCDC88C caused congenital hydrocephalus, some accompanied by seizures. In patients with epilepsy without acquired etiologies, we performed whole-exome sequencing (trio-based). Two de novo and two biallelic CCDC88C variants were identified in four cases with focal (partial) epilepsy. These variants did not present or had low frequencies in the gnomAD populations and were predicted to be damaging by multiple computational algorithms. Patients with de novo variants presented with adult-onset epilepsy, whereas patients with biallelic variants displayed infant-onset epilepsy. They all responded well to anti-seizure medications and were seizure-free. Further analysis showed that de novo variants were located at crucial domains, whereas one paired biallelic variants were located outside the crucial domains, and the other paired variant had a non-classical splicing and a variant located at crucial domain, suggesting a sub-molecular effect. CCDC88C variants associated with congenital hydrocephalus were all truncated, whereas epilepsy-associated variants were mainly missense, the proportion of which was significantly higher than that of congenital hydrocephalus-associated variants. CCDC88C is potentially associated with focal epilepsy with favorable outcome. The underlying mechanisms of phenotypic variation may correlation between genotype and phenotype.

Effect of tolvaptan on hyponatremia in a dog with syndrome of inappropriate secretion of antidiuretic hormone

A 1-year-old spayed female Miniature Schnauzer had chronic hyponatremia, accompanied by polyuria and polydipsia. Blood tests and urinalysis revealed severe hyponatremia, low plasma osmolality with euvolemia, and increased sodium excretion in urine. Hypothyroidism and hypoadrenocorticism were ruled out as causes. These findings led to the diagnosis of syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Magnetic resonance imaging (MRI) showed dilation of the lateral ventricles, indicating severe hydrocephalus. Tolvaptan, a vasopressin V2 receptor antagonist commonly used in human SIADH, was administered along with water restriction. This treatment resulted in a consistent increase in plasma sodium levels without any adverse effects. This case report represents the first documented evidence of the therapeutic efficacy of tolvaptan in treating SIADH in a dog.

Abdominal pseudocyst complicating ventriculoperitoneal shunt: A rare indication for ventriculopleural shunt conversion

Key Clinical Message

Abdominal pseudocyst is a rare complication of ventriculoperitoneal (VP) shunt placement. Ventriculopleural shunt (VPL) can be an effective treatment option for the recurrent complications of VP shunt failure.

Abstract

Abdominal pseudocyst (APC) is a rare complication of ventriculoperitoneal (VP) shunt placement for the treatment of congenital hydrocephalus. This case report presents a two-and-a-half-year-old male child who underwent VP shunt placement for aqueductal stenosis-related hydrocephalus. The patient subsequently developed recurrent shunt failure and an APC, which was managed initially by surgical excision of the cyst and repositioning of the catheter. However, shunt failure recurred. The patient underwent ventriculopleural (VPL) shunt conversion as a more viable option for recurrent blockage. Postoperatively, the patient developed respiratory distress with massive pleural effusion, which was treated with chest tube insertion. This case highlights the complexity of managing congenital hydrocephalus and its rare complication, APC. Prompt recognition and appropriate management of APC can lead to improved outcomes and minimize the need for invasive procedures. VPL shunt conversion can be considered an alternative treatment option when other treatments have failed. Further research is needed to establish guidelines for the management of APC and determine the long-term effectiveness of VPL shunting.

Convergence of multiple RNA-silencing pathways on GW182/TNRC6

The RNA-binding protein TRIM71/LIN-41 is a phylogenetically conserved developmental regulator that functions in mammalian stem cell reprogramming, brain development, and cancer. TRIM71 recognizes target mRNAs through hairpin motifs and silences them through molecular mechanisms that await identification. Here, we uncover that TRIM71 represses its targets through RNA-supported interaction with TNRC6/GW182, a core component of the miRNA-induced silencing complex (miRISC). We demonstrate that AGO2, TRIM71, and UPF1 each recruit TNRC6 to specific sets of transcripts to silence them. As cellular TNRC6 levels are limiting, competition occurs among the silencing pathways, such that the loss of AGO proteins or of AGO binding to TNRC6 enhances the activities of the other pathways. We conclude that a miRNA-like silencing activity is shared among different mRNA silencing pathways and that the use of TNRC6 as a central hub provides a means to integrate their activities.

Endoscopic Third Ventriculostomy in a 12-Year-Old With Recurrent Failure of Ventriculoperitoneal Shunts

With a success rate of about 80%, ventriculoperitoneal (VP) shunts are widely used for the treatment of hydrocephalus. Whether congenital or acquired, hydrocephalus is not a single disease entity. It can be caused by abnormal cerebrospinal fluid (CSF) reabsorption, obstruction along the ventricular pathways, or, very rarely, increased production of CSF itself. This case presents a patient with a history of congenital hydrocephalus with multiple failed VP shunts. Through various clinical examinations and diagnostic measures, an endoscopic third ventriculostomy was eventually performed. This case highlights the rare complications, yet a large possibility, that can lead to failure of VP shunts in more than one way and when it is appropriate for shunt reversal versus removal.

Risk factors of congenital hydrocephalus: a case-control study in a lower-middle-income country (Egypt)

OBJECTIVE

Hydrocephalus is the most common brain disorder in children and is more common in low- and middle-income countries. Research output on hydrocephalus remains sparse and of lower quality in low- and middle-income countries compared with high-income countries. Most studies addressing hydrocephalus epidemiology are retrospective registry studies entailing their inherent limitations and biases. This study aimed to investigate child-related, parental, and socioeconomic risk factors of congenital hydrocephalus (CH) in a lower-middle-income country.

METHODS

An investigator-administered questionnaire was used to query parents of patients with CH and controls who visited the authors' institution from 2017 until 2021. Patients with secondary hydrocephalus and children older than 2 years of age at diagnosis were excluded. Uni- and multivariable logistic regression was performed to identify the factors affecting CH development.

RESULTS

Seven hundred forty-one respondents (312 cases and 429 controls) were included in this study. The authors showed that maternal diseases during pregnancy (OR 3.12, 95% CI 1.96-5.03), a lack of periconceptional folic acid intake (OR 1.92, 95% CI 1.32-2.81), being a housewife (OR 2.66, 95% CI 1.51-4.87), paternal illiteracy (OR 1.65, 95% CI 1.02-2.69), parental consanguinity (OR 3.67, 95% CI 2.40-5.69), a history of other CNS conditions in the family (OR 2.93, 95% CI 1.24-7.34), conceiving a child via assisted fertilization techniques (OR 3.93, 95% CI 1.57-10.52), and the presence of other congenital anomalies (OR 2.57, 95% CI 1.38-4.87) were associated with an independent higher odds of a child having CH. Conversely, maternal hypertension (OR 0.22, 95% CI 0.09-0.48), older maternal age at delivery (OR 0.93, 95% CI 0.89-0.97), and having more abortions (OR 0.80, 95% CI 0.67-0.95) were negatively correlated with CH.

CONCLUSIONS

Multiple parental, socioeconomic, and child-related factors were associated with higher odds for developing CH. These results can be utilized to guide parental counseling and management, and direct social education and prevention programs.

A congenital hydrocephalus-causing mutation in Trim71 induces stem cell defects via inhibiting Lsd1 mRNA translation

Congenital hydrocephalus (CH) is a major cause of childhood morbidity. Mono-allelic mutations in Trim71, a conserved stem-cell-specific RNA-binding protein, cause CH; however, the molecular basis for pathogenesis mediated by these mutations remains unknown. Here, using mouse embryonic stem cells as a model, we reveal that the mouse R783H mutation (R796H in human) alters Trim71's mRNA substrate specificity and leads to accelerated stem-cell differentiation and neural lineage commitment. Mutant Trim71, but not wild-type Trim71, binds Lsd1 (Kdm1a) mRNA and represses its translation. Specific inhibition of this repression or a slight increase of Lsd1 in the mutant cells alleviates the defects in stem cell differentiation and neural lineage commitment. These results determine a functionally relevant target of the CH-causing Trim71 mutant that can potentially be a therapeutic target and provide molecular mechanistic insights into the pathogenesis of this disease.

Compound variants of FKTN, POMGNT1, and LAMB1 gene identified by prenatal whole-exome sequencing in three fetuses with congenital hydrocephalus

Congenital hydrocephalus (CH) is a severe birth defect, and genetics components is an important etiology. Whole-exome sequencing (WES) has been proven to be a feasible approach for prenatal diagnosis of CH. In this study, we carried out WES on three fetuses with cerebral ventriculomegaly. After bioinformation analysis and data filtering, three compound variants, c.919C>T(p.Arg307Ter)/c.1100del(p.Phe369fs) in FKTN, c.1449_1450insACAACG/c.1490G>C(p.Arg497Pro) in POMGNT1, and c.2690+1G>A/c.1447C>T(p.Arg483Cys) in LAMB1 were detected in the three fetuses. All the six variants were classified as likely pathogenic or pathogenic in accordance with the American College of Medical Genetics and Genomics-Association for Molecular Pathology guidelines. This study provides support for the potential of WES for the accurate prenatal diagnosis of fetal hydrocephalus and further demonstrated the genetic heterogeneity in patients with CH. The novel variants (c.1449_1450insACAACG and c.1490G>C in POMGNT1, c.2690+1G>A in LAMB1) expanded the gene mutational spectrum of CH and contributes to genetics counseling and pregnancy management.

Analysis of early neonatal case fatality rate among newborns with congenital hydrocephalus, a 2000-2014 multi-country registry-based study

BACKGROUND

Congenital hydrocephalus (CH) comprises a heterogeneous group of birth anomalies with a wide-ranging prevalence across geographic regions and registry type. The aim of the present study was to analyze the early neonatal case fatality rate (CFR) and total birth prevalence of newborns diagnosed with CH.

METHODS

Data were provided by 25 registries from four continents participating in the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR) on births ascertained between 2000 and 2014. Two CH rates were calculated using a Poisson distribution: early neonatal CFR (death within 7 days) per 100 liveborn CH cases (CFR) and total birth prevalence rate (BPR) per 10,000 births (including live births and stillbirths) (BPR). Heterogeneity between registries was calculated using a meta-analysis approach with random effects. Temporal trends in CFR and BPR within registries were evaluated through Poisson regression modeling.

RESULTS

A total of 13,112 CH cases among 19,293,280 total births were analyzed. The early neonatal CFR was 5.9 per 100 liveborn cases, 95% confidence interval (CI): 5.4-6.8. The CFR among syndromic cases was 2.7 times (95% CI: 2.2-3.3) higher than among non-syndromic cases (10.4% [95% CI: 9.3-11.7] and 4.4% [95% CI: 3.7-5.2], respectively). The total BPR was 6.8 per 10,000 births (95% CI: 6.7-6.9). Stratified by elective termination of pregnancy for fetal anomalies (ETOPFA), region and system, higher CFR were observed alongside higher BPR rates. The early neonatal CFR and total BPR did not show temporal variation, with the exception of a CFR decrease in one registry.

CONCLUSIONS

Findings of early neonatal CFR and total BPR were highly heterogeneous among registries participating in ICBDSR. Most registries with higher CFR also had higher BPR. Differences were attributable to type of registry (hospital-based vs. population-based), ETOPFA (allowed yes or no) and geographical regions. These findings contribute to the understanding of regional differences of CH occurrence and early neonatal deaths.

Prenatal Diagnosis of Walker-Warburg Syndrome due to Compound Mutations in the B3GALNT2 Gene

Background

Congenital hydrocephalus is one of the symptoms of Walker–Warburg syndrome that is attributed to the disruptions of the genes, among which the B3GALNT2 gene is rarely reported. A diagnosis of the Walker–Warburg syndrome depends on the clinical manifestations and the whole‐exome sequencing after birth, which is unfavorable for an early diagnosis.

Methods

Walker–Warburg Syndrome was suspected in two families with severe fetal congenital hydrocephalus. Whole‐exome sequencing and Sanger sequencing were performed on the affected fetuses.

Results

The compound heterozygous variants c.1A>G p.(Met1Val) and c.1151+1G>A, and c.1068dupT p.(D357*) and c.1052 T>A p.(L351*) in the B3GALNT2 gene were identified, which were predicted to be pathogenic and likely pathogenic, respectively. Walker–Warburg syndrome was prenatally diagnosed on the basis of fetal imaging and whole‐exome sequencing.

Conclusions

Our findings expand the spectrum of pathogenic mutations in Walker–Warburg syndrome and provide new insights into the prenatal diagnosis of the disease.

Hospital incidence and costs of congenital hydrocephalus in Spain: a multicenter retrospective study

BACKGROUND

Congenital hydrocephalus continues to represent a therapeutic challenge; however, few studies are available evaluating its hospital incidence and medical costs in Spain. This study aimed to review the profile of patients with this disorder admitted in Spanish hospitals and to estimate medical costs at the hospital level.

METHODS

Records of hospital admissions of patients with congenital hydrocephalus between 2010 and 2019 were obtained from a Spanish hospital discharge database and analyzed in a retrospective multicenter study.

RESULTS

A third of the patients included in the study were perinatal patients, however, the hospitalization rate in this group was higher to that in patients over 1 year of age. Perinatal patients required more ICU admissions and longer hospital stays, with more frequent surgical interventions and mechanical ventilation. The mean medical cost associated to congenital hydrocephalus was €9610 per admission, with significantly higher costs found in perinatal patients.

CONCLUSIONS

This study provides novel data on the hospital costs of congenital hydrocephalus in Spain. The hospital medical costs of this disorder have decreased over the past decade for perinatal patients but not in those aged 1 year and older, which should be considered in upcoming healthcare plans and resource allocation decisions.

Brain ventricles as windows into brain development and disease

Dilation of the fluid-filled cerebral ventricles (ventriculomegaly) characterizes hydrocephalus and is frequently seen in autism and schizophrenia. Recent work suggests that the genomic study of congenital hydrocephalus may be unexpectedly fertile ground for revealing insights into neural stem cell regulation, human cerebrocortical development, and pathogenesis of neuropsychiatric disease.

Genomic approaches to improve the clinical diagnosis and management of patients with congenital hydrocephalus

Congenital hydrocephalus (CH), characterized by incomplete clearance of CSF and subsequent enlargement of brain ventricles, is the most common congenital brain disorder. The lack of curative strategies for CH reflects a poor understanding of the underlying pathogenesis. Herein, the authors present an overview of recent findings in the pathogenesis of CH from human genetic studies and discuss the implications of these findings for treatment of CH. Findings from these omics data have the potential to reclassify CH according to a molecular nomenclature that may increase precision for genetic counseling, outcome prognostication, and treatment stratification. Beyond the immediate patient benefits, genomic data may also inform future clinical trials and catalyze the development of nonsurgical, molecularly targeted therapies. Therefore, the authors advocate for further application of genomic sequencing in clinical practice by the neurosurgical community as a diagnostic adjunct in the evaluation and management of patients diagnosed with CH.

Readmissions after ventricular shunting in pediatric patients with hydrocephalus: a Nationwide Readmissions Database analysis

OBJECTIVE

Cerebrospinal fluid diversion via ventricular shunting is a common surgical treatment for hydrocephalus in the pediatric population. No longitudinal follow-up data for a multistate population-based cohort of pediatric patients undergoing ventricular shunting in the United States have been published. In the current review of a nationwide population-based data set, the authors aimed to assess rates of shunt failure and hospital readmission in pediatric patients undergoing new ventricular shunt placement. They also review patient- and hospital-level factors associated with shunt failure and readmission.

METHODS

Included in this study was a population-based sample of pediatric patients with hydrocephalus who, in 2010-2014, had undergone new ventricular shunt placement and had sufficient follow-up, as recorded in the Nationwide Readmissions Database. The authors analyzed the rate of revision within 6 months, readmission rates at 30 and 90 days, and potential factors associated with shunt failure including patient- and hospital-level variables and type of hydrocephalus.

RESULTS

A total of 3520 pediatric patients had undergone initial ventriculoperitoneal shunt placement for hydrocephalus at an index admission. Twenty percent of these patients underwent shunt revision within 6 months. The median time to revision was 44.5 days. Eighteen percent of the patients were readmitted within 30 days and 31% were readmitted within 90 days. Different-hospital readmissions were rare, occurring in ≤ 6% of readmissions. Increased hospital volume was not protective against readmission or shunt revision. Patients with grade 3 or 4 intraventricular hemorrhage were more likely to have shunt malfunctions. Patients who had private insurance and who were treated at a large hospital were less likely to be readmitted.

CONCLUSIONS

In a nationwide, population-based database with longitudinal follow-up, shunt failure and readmission were common. Although patient and hospital factors were associated with readmission and shunt failure, system-wide phenomena such as insufficient centralization of care and fragmentation of care were not observed. Efforts to reduce readmissions in pediatric patients undergoing ventricular shunt procedures should focus on coordinating care in patients with complex neurological diseases and on reducing healthcare disparities associated with readmission.

Ventriculoperitoneal shunt infection rates using a standard surgical technique, including topical and intraventricular vancomycin: the Children's Hospital Oakland experience

OBJECTIVE

Ventriculoperitoneal (VP) shunt infections are common complications after shunt operations. Despite the use of intravenous antibiotics, the incidence of infections remains high. Though antibiotic-impregnated catheters (AICs) are commonly used, another method of infection prophylaxis is the use of intraventricular (IVT) antibiotics. The authors describe their single-institution experience with a standard shunt protocol utilizing prophylactic IVT and topical vancomycin administration and report the incidence of pediatric shunt infections.

METHODS

Three hundred two patients undergoing VP shunt procedures with IVT and topical vancomycin between 2006 and 2016 were included. Patients were excluded if their age at surgery was greater than 18 years. Shunt operations were performed at a single institution following a standard shunt protocol implementing IVT and topical vancomycin. No AICs were used. Clinical data were retrospectively collected from the electronic health records.

RESULTS

Over the 11-year study period, 593 VP shunt operations were performed with IVT and topical vancomycin, and a total of 19 infections occurred (incidence 3.2% per procedure). The majority of infections (n = 10, 52.6%) were caused by Staphylococcus epidermidis. The median time to shunt infection was 3.7 weeks. On multivariate analysis, the presence of a CSF leak (OR 31.5 [95% CI 8.8-112.6]) and age less than 6 months (OR 3.6 [95% CI 1.2-10.7]) were statistically significantly associated with the development of a shunt infection. A post hoc analysis comparing infection rates after procedures that adhered to the shunt protocol and those that did not administer IVT and topical vancomycin, plus historical controls, revealed a difference in infection rates (3.2% vs 6.9%, p = 0.03).

CONCLUSIONS

The use of a standardized shunt operation technique that includes IVT and topical vancomycin is associated with a total shunt infection incidence of 3.2% per procedure, which compares favorably with the reported rates of shunt infection in the literature. The majority of infections occurred within 2 months of surgery and the most common causative organism was S. epidermidis. Young age (< 6 months) at the time of surgery and the presence of a postoperative CSF leak were statistically significantly associated with postoperative shunt infection on multivariate analysis. The results are hypothesis generating, and the authors propose that IVT and topical administration of vancomycin as part of a standardized shunt operation protocol may be an appropriate option for preventing pediatric shunt infections.

Human Herpesvirus-6 Meningitis in a Premature Infant with Fevers: A Case and Literature Review

Human herpesvirus-6 (HHV-6) is a common virus that can cause nearly universal infection in infancy and early childhood. It typically manifests as an acute febrile illness. We describe a case of a premature infant with congenital hydrocephalus secondary to aqueductal stenosis with a ventriculoperitoneal shunt in place who developed intermittent fevers while she was admitted to the neonatal intensive care unit. She was ultimately diagnosed with acute HHV-6 meningitis. In addition to this report, we present a literature review regarding this virus’s potential modes of transmission and forms of clinical presentation in the neonatal period.

A novel nonsense mutation in the L1CAM gene responsible for X-linked congenital hydrocephalus

BACKGROUND

Congenital hydrocephalus is a descriptive diagnosis of symptoms, that are present for numerous reasons, including chromosomal disorders, genetic mutations, intrauterine infection and hemorrhage, amongst other factors. Mutation of L1CAM gene is the most frequent cause of congenital hydrocephalus, contributing to approximately 30% of X-linked congenital hydrocephalus.

METHODS

In the present study, we used whole-exome sequencing and Sanger sequencing to investigate an aborted male fetus present with severe congenital hydrocephalus at 24 weeks of gestation, whose mother had a history of two previous voluntary terminations of pregnancies as a result of hydrocephalus. Magnetic resonance imaging, an autopsy and electron microscopy were performed and the phenotypic changes were described.

RESULTS

Whole-exome sequencing in the fetus, as well as variant segregation analysis, revealed a novel maternally derived hemizygous nonsense mutation (c.2865G>A; p. Y955*) in exon 21 of the L1CAM gene (NM_000425.4). Severe hydrocephalus was observed along with marked dilatation of lateral ventricles. An electron micrograph of the surface of lateral ventricle walls revealed a lack of ependymal cilia.

CONCLUSION

The present study suggests that L1CAM mutation screening should be considered for a male fetus with isolated hydrocephalus, especially with a family history, which could facilitate prenatal diagnosis in a subsequent pregnancy.

Assessment of the Knowledge of Risk Factors of Congenital Hydrocephalus among Mothers Attending Antenatal Clinics in a Rural Tertiary Hospital Irrua, Edo State

Background  One of the congenital central nervous system malformations with great impact on the mental and psychosocial development of children is congenital hydrocephalus and it happens to be one of the most common. A large vacuum exists between knowledge on maternal environmental risk factors associated with congenital hydrocephalus, most especially in our rural community which consists of a large segment of our society. Our study aimed to determine the knowledge and perception of mothers on factors existing in the maternal environment that potentially puts an increased risk of developing congenital hydrocephalus. Materials and Methods  This was a cross-sectional study design spanning a period of 8 months (March 2018-October 2018), in which the knowledge and perception of the risk factors of congenital hydrocephalus among mothers attending antenatal clinic in Irrua specialist teaching hospital, a rural tertiary hospital in Irrua, Edo state, Nigeria, were assessed using a random sampling technique. Interviewer-administered questionnaires (reviewed and validated) were used. The data collected were entered and analyzed using SPSS version 21. Results  The findings showed varying levels of knowledge of congenital hydrocephalus. Less than half (44.0%) of the respondents had poor knowledge, 34.5% had fair knowledge, and 21.6% had good knowledge. There was a statistically significant relationship between knowledge of congenital hydrocephalus and respondents' knowledge of the risk factors of congenital hydrocephalus. Most (52.6%) had good perception of the risk factors of congenital hydrocephalus, while 23.3% had poor perception. Conclusion  This study revealed a fairly good knowledge of congenital hydrocephalus and its risk factors among mothers, most especially those with a good level of education.

Intracisternal BioGlue injection in the fetal lamb: a novel model for creation of obstructive congenital hydrocephalus without additional chemically induced neuroinflammation

OBJECTIVE

The authors hypothesized that new agents such as BioGlue would be as efficacious as kaolin in the induction of hydrocephalus in fetal sheep.

METHODS

This study was performed in 34 fetal lambs randomly divided into 2 studies. In the first study, fetuses received kaolin, BioGlue (2.0 mL), or Onyx injected into the cisterna magna, or no injection (control group) between E85 and E90. In the second study, fetuses received 2.0-mL or 2.5-mL injections of BioGlue into the cisterna magna between E85 and E90. Fetuses were monitored using ultrasound to assess lateral ventricle size and progression of hydrocephalus. The fetuses were delivered (E120-E125) and euthanized for histological analysis. Selected brain sections were stained for ionized calcium binding adaptor 1 (Iba1) and glial fibrillary acidic protein (GFAP) to assess the presence and activation of microglia and astroglia, respectively. Statistical comparisons were performed with Student's t-test for 2 determinations and ANOVA 1-way and 2-way repeated measures for multiple determinations.

RESULTS

At 30 days after injection, the lateral ventricles were larger in all 3 groups that had undergone injection than in controls (mean diameter in controls 3.76 ± 0.05 mm, n = 5). However, dilatation was greater in the fetuses injected with 2 mL of BioGlue (11.34 ± 4.76 mm, n = 11) than in those injected with kaolin (6.4 ± 0.98 mm, n = 7) or Onyx (5.7 ± 0.31 mm, n = 6) (ANOVA, *p ≤ 0.0001). Fetuses injected with 2.0 mL or 2.5 mL of BioGlue showed the same ventricle dilatation but it appeared earlier (at 10 days postinjection) in those injected with 2.5 mL. The critical threshold of ventricle dilatation was 0.1 for all the groups, and only the BioGlue 2.0 mL and BioGlue 2.5 mL groups exceeded this critical value (at 30 days and 18 days after injection, respectively) (ANOVA, *p ≤ 0.0001). Moderate to severe hydrocephalus with corpus callosum disruption was observed in all experimental groups. All experimental groups showed ventriculomegaly with significant microgliosis and astrogliosis in the subventricular zone around the lateral ventricles. Only kaolin resulted in significant microgliosis in the fourth ventricle area (ANOVA, *p ≤ 0.005).

CONCLUSIONS

The results of these studies demonstrate that BioGlue is more effective than Onyx or kaolin for inducing hydrocephalus in the fetal lamb and results in a volume-related response by obstructive space-occupancy without local neuroinflammatory reaction. This novel use of BioGlue generates a model with potential for new insights into hydrocephalus pathology and the development of therapeutics in obstructive hydrocephalus. In addition, this model allows for the study of acute and chronic obstructive hydrocephalus by using different BioGlue volumes for intracisternal injection.

Recessive Inheritance of Congenital Hydrocephalus With Other Structural Brain Abnormalities Caused by Compound Heterozygous Mutations in ATP1A3

Background

ATP1A3 encodes the α3 subunit of the Na⁺/K⁺ ATPase, a fundamental ion-transporting enzyme. Primarily expressed in neurons, ATP1A3 is mutated in several autosomal dominant neurological diseases. To our knowledge, damaging recessive genotypes in ATP1A3 have never been associated with any human disease. Atp1a3 deficiency in zebrafish results in hydrocephalus; however, no known association exists between ATP1A3 and human congenital hydrocephalus (CH).

Methods

We utilized whole-exome sequencing (WES), bioinformatics, and computational modeling to identify and characterize novel ATP1A3 mutations in a patient with CH. We performed immunohistochemical studies using mouse embryonic brain tissues to characterize Atp1a3 expression during brain development.

Results

We identified two germline mutations in ATP1A3 (p. Arg19Cys and p.Arg463Cys), each of which was inherited from one of the patient’s unaffected parents, in a single patient with severe obstructive CH due to aqueductal stenosis, along with open schizencephaly, type 1 Chiari malformation, and dysgenesis of the corpus callosum. Both mutations are predicted to be highly deleterious and impair protein stability. Immunohistochemical studies demonstrate robust Atp1a3 expression in neural stem cells (NSCs), differentiated neurons, and choroid plexus of the mouse embryonic brain.

Conclusion

These data provide the first evidence of a recessive human phenotype associated with mutations in ATP1A3, and implicate impaired Na⁺/K⁺ ATPase function in the pathogenesis of CH.

GemC1 is a critical switch for neural stem cell generation in the postnatal brain

The subventricular zone (SVZ) is one of two main niches where neurogenesis persists during adulthood, as it retains neural stem cells (NSCs) with self-renewal capacity and multi-lineage potency. Another critical cellular component of the niche is the population of postmitotic multiciliated ependymal cells. Both cell types are derived from radial glial cells that become specified to each lineage during embryogenesis. We show here that GemC1, encoding Geminin coiled-coil domain-containing protein 1, is associated with congenital hydrocephalus in humans and mice. Our results show that GemC1 deficiency drives cells toward a NSC phenotype, at the expense of multiciliated ependymal cell generation. The increased number of NSCs is accompanied by increased levels of proliferation and neurogenesis in the postnatal SVZ. Finally, GemC1-knockout cells display altered chromatin organization at multiple loci, further supporting a NSC identity. Together, these findings suggest that GemC1 regulates the balance between NSC generation and ependymal cell differentiation, with implications for the pathogenesis of human congenital hydrocephalus.

Trim71/lin-41 Links an Ancient miRNA Pathway to Human Congenital Hydrocephalus

Tripartite motif 71 (Trim71)/lineage defective 41 (lin-41) is the primary target of the ancient lethal 7 (let-7) miRNA that is essential for survival and development across animal phylogeny. Recent work identified Trim71 as a critical regulator of mammalian neural stem cell (NSC) fate and a bona fide human disease gene in congenital hydrocephalus (CH). Studying TRIM71 as a paradigm of NSC involvement in CH is a remarkable opportunity to better understand the mechanisms that regulate the timing of brain development and the pathogenesis of the most common pediatric neurosurgical disorder.

[Factors of endoscopic third ventriculostomy efficacy in infants with obstructive hydrocephalus under one year of age]

Endoscopic surgery for obstructive hydrocephalus in children is an alternative to shunts. Currently, the efficacy of endoscopic third ventriculostomy (ETV) in infants up to one year of age is increasingly discussed among neurosurgeons. To increase the efficacy of ETV, many surgeons raise the question: what factors may affect the efficacy of this procedure in the younger age group?

OBJECTIVE

To study the factors affecting the efficacy of ETV.

MATERIAL AND METHODS

A total of 88 ETVs were performed in infants under one year of age in our clinic in 2012-2016. Subsequently, 43 (48.9%) children underwent CSF shunting, and one child underwent repeated ETV. The mean time until the appearance of clinical signs of stoma closure was 3.9 months (116 days).

RESULTS

The procedure was most effective in the case of congenital obstructive hydrocephalus (64.5% of successful operations) and also in children over the age of 6 months (63.6% of successful operations). The efficacy in post-hemorrhagic hydrocephalus was 40%. The efficacy in grade 4 intraventricular hemorrhage was lowest and amounted to 25%. The total efficacy of ETV in children under one year of age in our study was 51.1%.

CONCLUSION

In the case of congenital obstructive hydrocephalus, the efficacy of ETV is maximal and amounts to 64.5%. To achieve the highest efficacy of ETV in infants under one year of age, careful selection of patients at the preoperative stage is necessary, with allowance for many factors affecting treatment outcome.

A Case of Recurrent Bacterial Meningitis Due to Retained 54-Year-Old Ureterodural Anastomosis

Ventriculoperitoneal shunts are the current treatment of choice for congenital hydrocephalus. It is rare for physicians to see patients with alternative types of shunting devices. Lumboureteral shunts, once popular from the 1940s to 1960s, decompress via the genitourinary system. Immediate complications were dehydration, electrolyte imbalances, infection, and the sacrifice of a functional kidney. Long-term complications include retrograde meningitis due to urinary tract infections. Three shunt types have been documented: polyethylene, silicone rubber, and ureterodural anastomosis. Routine imaging cannot detect a ureterodural anastomosis, and if suspected, computed tomography myelogram is needed for confirmation. This article presents the case of a man with long-standing ureterodural anastomosis that required ligation after recurrent episodes of acute meningitis secondary to urinary retention.

De Novo Mutation in Genes Regulating Neural Stem Cell Fate in Human Congenital Hydrocephalus

Congenital hydrocephalus (CH), featuring markedly enlarged brain ventricles, is thought to arise from failed cerebrospinal fluid (CSF) homeostasis and is treated with lifelong surgical CSF shunting with substantial morbidity. CH pathogenesis is poorly understood. Exome sequencing of 125 CH trios and 52 additional probands identified three genes with significant burden of rare damaging de novo or transmitted mutations: TRIM71 (p = 2.15 × 10^-7), SMARCC1 (p = 8.15 × 10^-10), and PTCH1 (p = 1.06 × 10^-6). Additionally, two de novo duplications were identified at the SHH locus, encoding the PTCH1 ligand (p = 1.2 × 10^-4). Together, these probands account for ∼10% of studied cases. Strikingly, all four genes are required for neural tube development and regulate ventricular zone neural stem cell fate. These results implicate impaired neurogenesis (rather than active CSF accumulation) in the pathogenesis of a subset of CH patients, with potential diagnostic, prognostic, and therapeutic ramifications.

Trends in the prevalence of congenital hydrocephalus in 14 cities in Liaoning province, China from 2006 to 2015 in a population-based birth defect registry from the Liaoning Women and Children's Health Hospital

The aim of this study was to assess the prevalence and trends of congenital hydrocephalus (CH) using a large population-based sample with cases retrieved from the Liaoning Birth Defects Registry, which included 14 cities, over a 10-year period. CH prevalence, percent change, average change, and contribution rates of each city were calculated. Statistical analysis was performed using a Poisson regression model. There was a total of 3008 CH cases among 3,248,954 live births during the observational period (9.26 cases/10,000 live births). On average, the prevalence of CH had significantly decreased by 11.84% each year (P < 0.01). The three leading cities with the highest prevalence of CH were Chaoyang (13.73/10,000), Huludao (13.18/10,000), and Fuxin (12.71/10,000), while Yingkou (6.06/10,000), Dalian (6.27/10,000), and Anshan (6.56/10,000) had the lowest prevalence. Notably, significantly decreasing trends were observed in 10 (71.4%) of these 14 cities. In addition, the cities of Fushun, Shenyang, and Dalian had contributed to more than one-third of the decreasing trend in Liaoning province. In conclusion, this study provides evidence of the decreasing prevalence of CH over a 10-year period (2006–2015) in Liaoning province. Preventative efforts should be strengthened to further reduce the risk of CH in these high prevalence areas.

Congenital Hydrocephalus, Corpus Callosum Agenesis, and Prosencephalic Cyst with Supernumerary Nostril: A Neurocristopathy

A 3-month-old-male infant presented with enlargement of head since birth. Clinical and radiological evaluation revealed congenital hydrocephalus, corpus callosum agenesis, prosencephalic cyst, and cranial vault deficiency with supernumerary nostril on the left side. Right ventriculoperitoneal shunt (Chhabra shunt) surgery was performed. The patient did well postoperatively. Parents of the patient have been counseled for repair of supernumerary nostril. Congenital hydrocephalus with corpus callosum agenesis is rare. Furthermore, supernumerary nostril is a very rare anomaly with <40 cases reported in the literature till date. To the best of our knowledge, congenital hydrocephalus, corpus callosum agenesis, prosencephalic cyst, and cranial vault deficiency associated with supernumerary nostril have not been reported till date. We herein briefly review the pertinent literature and describe the embryopathogenesis of this rare association. We propose that this association is a neurocristopathy.

Ultrastructural Pathology of Oligodendroglial Cells in Traumatic and Hydrocephalic Human Brain Edema: A Review

Oligodendroglial cell changes in human traumatic brain injuries and hydrocephalus have been reviewed and compared with experimental brain edema. Resting unreactive oligodendrocytes, reactive oligodendrocytes, anoxic-ischemic oligodendrocytes, hyperthrophic phagocytic oligodendrocytes, and apoptotic oligodendrocytes are found. Anoxic-ischemic oligodendrocytes exhibit enlargement of endoplasmic reticulum, Golgi complex, and enlargement and disassembly of nuclear envelope. They appear in contact with degenerated myelinated axons. Hypertrophic phagocytic oligodendrocytes engulf degenerated myelinated axons exerting myelinolytic effects. A continuum oncotic and apoptotic cell death type leading to necrosis is observed. The vasogenic and cytotoxic components of brain edema are discussed in relation to oligodendroglial cell changes and reactivity.

Restricted Pax3 Deletion within the Neural Tube Results in Congenital Hydrocephalus

Congenital hydrocephalus is a common birth-defect whose developmental origins are poorly understood. Pax3-null mutants show defects in myogenesis, neural tube closure, neural crest morphogenesis, and heart development that, consequently, results in embryonic lethality. Here we demonstrate that conditional deletion of the mouse Pax3 transcription factor results in fully-penetrant congenital obstructive hydrocephalus. To identify the role of Pax3 during cranial development, we deleted Pax3 within the neuroepithelium (via Pax7^−Cre), in the neural crest (via P0-Cre), and in both the neuroepithelium and the neural crest (via Wnt1-Cre). Only conditional mutants generated using Pax7^−Cre or Wnt1-Cre developed early onset congenital hydrocephalus due to stenosis of the third ventricle, suggesting that loss of neuroepithelial Pax3 is sufficient to disturb third ventricle morphogenesis. Dilation of lateral ventricles occurs as early as E14.5, and lineage-mapping revealed that the neuroepithelial cells in the conditional mutants are present, but fail to undergo normal differentiation at the stenotic site. Concomitant with a narrowing of the mutant third ventricle, we detected ectopic apoptosis, reduced proliferation, and abnormal β-catenin localization. Furthermore, consistent with the overlapping expression pattern of Pax3 and Pax7 in early cranial neuroepithelium, we demonstrated a combinatorial role, as compound Pax3/Pax7 heterozygotes display partially-penetrant congenital hydrocephalus. These murine data provide an experimental paradigm underpinning clinical observations of the presence of PAX3 mutations in some hydrocephalic patients.

Increased levels of tumour necrosis factor alpha (TNFα) but not transforming growth factor-beta 1 (TGFβ1) are associated with the severity of congenital hydrocephalus in the hyh mouse

AIMS

Here, we tested the hypothesis that glial responses via the production of cytokines such as transforming growth factor-beta 1 (TGFβ1) and tumour necrosis factor alpha (TNFα), which play important roles in neurodegenerative diseases, are correlated with the severity of congenital hydrocephalus in the hyh mouse model. We also searched for evidence of this association in human cases of primary hydrocephalus.

METHODS

Hyh mice, which exhibit either severe or compensated long-lasting forms of hydrocephalus, were examined and compared with wild-type mice. TGFβ1, TNFα and TNFαR1 mRNA levels were quantified using real-time PCR. TNFα and TNFαR1 were immunolocalized in the brain tissues of hyh mice and four hydrocephalic human foetuses relative to astroglial and microglial reactions.

RESULTS

The TGFβ1 mRNA levels were not significantly different between hyh mice exhibiting severe or compensated hydrocephalus and normal mice. In contrast, severely hydrocephalic mice exhibited four- and two-fold increases in the mean levels of TNFα and TNFαR1, respectively, compared with normal mice. In the hyh mouse, TNFα and TNFαR1 immunoreactivity was preferentially detected in astrocytes that form a particular periventricular reaction characteristic of hydrocephalus. However, these proteins were rarely detected in microglia, which did not appear to be activated. TNFα immunoreactivity was also detected in the glial reaction in the small group of human foetuses exhibiting hydrocephalus that were examined.

CONCLUSIONS

In the hyh mouse model of congenital hydrocephalus, TNFα and TNFαR1 appear to be associated with the severity of the disease, probably mediating the astrocyte reaction, neurodegenerative processes and ischaemia.

Prenatal Diagnosis of Walker-Warburg Syndrome Using Single Nucleotide Polymorphism Array: A Clinical Experience from Three Related Palestinian Families with Congenital Hydrocephalus

Background Congenital hydrocephalus is a common and often disabling disorder. Various syndromic forms of hydrocephalus have been reported in the Palestinian population including Walker-Warburg syndrome (WWS), Carpenter syndrome, and Meckel syndrome. Aim In this report we discuss the antenatal diagnosis of congenital hydrocephalus in three related Palestinian families. Method Single nucleotide polymorphism (SNP) array was performed prenatally for the third affected fetus. Results A diagnosis of WWS was found and molecular testing revealed a known pathogenic mutation in the POMT2 gene. An affected fetus from the other family was diagnosed and tested postnatally in light of this finding. Testing of another affected stillborn offspring was performed and revealed the same mutation. Conclusions Here, we show that the use of prenatal SNP array testing can be helpful in elucidating the etiology of congenital hydrocephalus and in guiding appropriate perinatal care. Also, testing for this specific POMT2 mutation should be considered in cases of prenatally detected hydrocephalus in Palestinian families.

The natural history of Dandy-Walker syndrome in the United States: A population-based analysis

BACKGROUND

Dandy-Walker syndrome (DWS) is a congenital disorder typically manifesting with hydrocephalus. The classic anatomic hallmarks of DWS are hypoplasia of the cerebellar vermis, anterior-posterior enlargement of the posterior fossa, upward displacement of the torcula and transverse sinuses, and cystic dilatation of the fourth ventricle.

AIMS

Although optimal treatment of DWS typically requires neurosurgical intervention to prevent intracranial pressure increases incompatible with life, the natural history of this disorder has yet to be evaluated on a nationwide level.

SETTINGS AND DESIGN/MATERIALS AND METHODS

The Kids' Inpatient Database covering 1997-2003 was used for analysis. Children younger than age 18 admitted for DWS (ICD-9-CM = 742.3) were analyzed with a matched control group. The primary procedure codes for operative CSF drainage were coded into the analysis. The incidence of DWS was 0.136%; 14,599 DWS patients were included.

STATISTICAL ANALYSIS USED

Multiple logistic regression models were used. Odds ratios (OR) were reported with 95% confidence intervals.

RESULTS AND CONCLUSIONS

Mortality (OR = 10.02; P < 0.0001) and adverse discharge disposition (OR = 4.59; P < 0.0001) were significantly greater in DWS patients compared with controls. 20.4% of DWS patients received operative cerebrospinal fluid (CSF) drainage, 81-times more than controls (P < 0.0001). CSF drainage reduced mortality by 44% among DWS patients (P < 0.0001). Although DWS is associated with a 10-fold increase in mortality, operative CSF drainage nearly halves the mortality rate. Based on these findings (Class IIB evidence), it is likely that the increased mortality associated with DWS is directly attributable to the nearly 80% of DWS patients who did not receive operative CSF drainage for hydrocephalus. Consequently, increased access to neurosurgical intervention could reduce the mortality rate of DWS towards that of the general population.

L1CAM whole gene deletion in a child with L1 syndrome

L1 syndrome is a group of overlapping, X-linked disorders caused by mutations in L1CAM. Clinical phenotypes within L1 syndrome include X-linked hydrocephalus with stenosis of the aqueduct of sylvius (HSAS); mental retardation, adducted thumbs, shuffling gait, and aphasia (MASA) syndrome; spastic paraplegia type 1; and agenesis of the corpus callosum. Over 200 mutations in L1CAM have been reported; however, only a few large gene deletions have been observed. We report on a 4-month-old male with a de novo whole gene deletion of L1CAM presenting with congenital hydrocephalus, aqueductal stenosis, and adducted thumbs. Initial failure of L1CAM gene sequencing suggested the possibility of a whole gene deletion of L1CAM. Further investigation through chromosome microarray analysis showed a 62Kb deletion encompassing the first exon of the PDZD4 gene and the entire L1CAM gene. Investigations into genotype-phenotype correlations have suggested that mutations leading to truncated or absent L1 protein cause more severe forms of L1 syndrome. Based on the presentation of the proband and other reported patients with whole gene deletions, we provide further evidence that L1CAM whole gene deletions result in L1 syndrome with a severe phenotype, deletions of PDZD4 do not cause additional manifestations, and that X-linked nephrogenic diabetes insipidus reported in a subset of patients with large L1CAM deletions results from the loss of AVPR2.

Enterocutaneous fistulae presenting as a late complication of a non-functioning Ventriculo- Peritoneal shunt catheter

A patient with spina bifida and hydrocephalus who had undergone multiple shunt revisions, presented with a 9 month history of chronic discharging sinuses related to a retained shunt catheter not visible on x-ray. This case report demonstrates the importance of clinical history and investigation in patients with retained catheters presenting with cutaneous sinuses.