Pathophysiology of congenital and neonatal hydrocephalus

Ventricular-subventricular zone stem cell niche adaptations in a mouse model of post-infectious hydrocephalus

Congenital post-infectious hydrocephalus (PIH) is a condition characterized by enlargement of the ventricular system, consequently imposing a burden on the associated stem cell niche, the ventricular-subventricular zone (V-SVZ). To investigate how the V-SVZ adapts in PIH, we developed a mouse model of influenza virus-induced PIH based on direct intracerebroventricular injection of mouse-adapted influenza virus at two distinct time points: embryonic day 16 (E16), when stem cells line the ventricle, and postnatal day 4 (P4), when an ependymal monolayer covers the ventricle surface and stem cells retain only a thin ventricle-contacting process. Global hydrocephalus with associated regions of astrogliosis along the lateral ventricle was found in 82% of the mice infected at P4. Increased ependymogenesis was observed at gliotic borders and throughout areas exhibiting intact ependyma based on tracking of newly divided cells. Additionally, in areas of intact ependyma, stem cell numbers were reduced; however, we found no significant reduction in new neurons reaching the olfactory bulb following onset of ventriculomegaly. At P4, injection of only the non-infectious viral component neuraminidase resulted in limited, region-specific ventriculomegaly due to absence of cell-to-cell transmission. In contrast, at E16 intracerebroventricular injection of influenza virus resulted in death at birth due to hypoxia and multiorgan hemorrhage, suggesting an age-dependent advantage in neonates, while the viral component neuraminidase resulted in minimal, or no, ventriculomegaly. In summary, we tracked acute adaptations of the V-SVZ stem cell niche following onset of ventriculomegaly and describe developmental changes that help mitigate the severity of congenital PIH.

Temporal trends in paediatric hydrocephalus - Rising prematurity and persistent ophthalmological challenges

AIM

To study changes in aetiology, prematurity, comorbidity and ophthalmological outcomes in children with surgically treated hydrocephalus to provide information needed to maintain the best possible healthcare for a fragile and changing population.

METHODS

Two population-based cohorts, born two decades apart in Region Västra Götaland Sweden, surgically treated for hydrocephalus at Sahlgrenska University Hospital in Gothenburg were recruited at approximately 10 years of age. The participants were examined according to an ophthalmological protocol, including history taking regarding perceptual visual dysfunction (PVD). Gestational age, aetiology and comorbidities were registered.

RESULTS

The 1989-1993 group, comprised 52 children (48% girls; mean age 10, range 7.7-12.8 years), was compared with 24 children, born in 2007-2012 (29% girls; mean age 10, range 7.0-13.8 years). Extreme prematurity (gestational age ≤ 28 weeks) increased over time (p = 0.001). The vast majority of the children showed ophthalmological abnormalities, although motility defects and nystagmus decreased in the latter population. Subnormal visual acuity was associated with extreme prematurity (RR = 4.69; p = 0.030), and PVD with learning disability (RR = 2.44; p = 0.032).

CONCLUSION

Paediatric hydrocephalus populations may change with improved healthcare. Since a high percentage shows ophthalmological abnormalities and more children are born extremely preterm, the entirety needs consideration both neurologically and ophthalmologically.

Use of neurofilament light chain to identify structural brain diseases in dogs

BACKGROUND

Neurofilament light chain (NfL) is released into the peripheral circulation by damaged axons.

OBJECTIVES

To evaluate the diagnostic value of serum NfL concentration in dogs with intracranial diseases.

ANIMALS

Study included 37 healthy dogs, 31 dogs with idiopathic epilepsy (IE), 45 dogs with meningoencephalitis of unknown etiology (MUE), 20 dogs with hydrocephalus, and 19 dogs with brain tumors.

METHODS

Cohort study. Serum NfL concentrations were measured in all dogs using single-molecule array technology.

RESULTS

Serum NfL concentration in dogs with each structural disease was significantly higher than in healthy dogs and dogs with IE (P = .01). The area under the receiver operating characteristic curve of NfL for differentiating between dogs with structural diseases and IE was 0.868. An optimal cutoff value of the NfL 27.10 pg/mL had a sensitivity of 86.67% and a specificity of 74.19% to differentiate the dogs with IE from those with structural brain diseases. There were significant correlations between NfL concentrations and lesion size: (1) MUE, P = .01, r = 0.429; (2) hydrocephalus, P = .01, r = 0.563.

CONCLUSIONS AND CLINICAL IMPORTANCE

Serum NfL could be a useful biomarker for distinguishing IE from structural diseases in dogs and predicting the lesion sizes of MUE and hydrocephalus.

Evaluation of the behavioral, histopathological, and immunohistochemical effects resulting from ventriculosubcutaneous shunt obstruction in kaolin-induced hydrocephalus in rats

PURPOSE

Hydrocephalus is a brain disease prevalent in the pediatric population that presents complex pathophysiology and multiple etiologies. The best treatment is still ventricular shunting. Mechanical obstruction is the most frequent complication, but the resulting pathological effects are still unknown.

OBJECTIVE

Evaluation and comparison of clinical, histopathological, and immunohistochemical aspects in the acute phase of experimental hydrocephalus induced by kaolin, after treatment with adapted shunt, and after shunt obstruction and posterior disobstruction.

METHODS

Wistar rats aged 7 days were used and divided into 4 groups: control group without kaolin injection (n = 6), untreated hydrocephalic group (n = 5), hydrocephalic group treated with ventriculosubcutaneous shunt (DVSC) (n = 7), and hydrocephalic group treated with shunt, posteriorly obstructed and disobstructed (n = 5). The animals were submitted to memory and spatial learning evaluation through the Morris water maze test. The rats were sacrificed at 28 days of age and histological analysis of the brains was performed with luxol fast blue, in addition to immunohistochemical analysis in order to evaluate reactive astrocytosis, inflammation, neuronal labeling, and apoptotic activity.

RESULTS

The group with shunt obstruction had worse performance in memory tests. Reactive astrocytosis was more evident in this group, as was the inflammatory response.

CONCLUSIONS

Obstruction of the shunt results in impaired performance of behavioral tests and causes irreversible histopathological changes when compared to findings in the group with treated hydrocephalus, even after unblocking the system. The developed model is feasible and efficient in simulating the clinical context of shunt dysfunction.

Cerebral furin deficiency causes hydrocephalus in mice

Furin is a pro-protein convertase that moves between the trans-Golgi network and cell surface in the secretory pathway. We have previously reported that cerebral overexpression of furin promotes cognitive functions in mice. Here, by generating the brain-specific furin conditional knockout (cKO) mice, we investigated the role of furin in brain development. We found that furin deficiency caused early death and growth retardation. Magnetic resonance imaging showed severe hydrocephalus. In the brain of furin cKO mice, impaired ciliogenesis and the derangement of microtubule structures appeared along with the down-regulated expression of RAB28, a ciliary vesicle protein. In line with the widespread neuronal loss, ependymal cell layers were damaged. Further proteomics analysis revealed that cell adhesion molecules including astrocyte-enriched ITGB8 and BCAR1 were altered in furin cKO mice; and astrocyte overgrowth was accompanied by the reduced expression of SOX9, indicating a disrupted differentiation into ependymal cells. Together, whereas alteration of RAB28 expression correlated with the role of vesicle trafficking in ciliogenesis, dysfunctional astrocytes might be involved in ependymal damage contributing to hydrocephalus in furin cKO mice. The structural and molecular alterations provided a clue for further studying the potential mechanisms of furin.

Modulation of Cerebrospinal Fluid Dysregulation via a SPAK and OSR1 Targeted Framework Nucleic Acid in Hydrocephalus

Hydrocephalus is one of the most common brain disorders and a life-long incurable condition. An empirical "one-size-fits-all" approach of cerebrospinal fluid (CSF) shunting remains the mainstay of hydrocephalus treatment and effective pharmacotherapy options are currently lacking. Macrophage-mediated ChP inflammation and CSF hypersecretion have recently been identified as a significant discovery in the pathogenesis of hydrocephalus. In this study, a pioneering DNA nano-drug (TSOs) is developed by modifying S2 ssDNA and S4 ssDNA with SPAK ASO and OSR1 ASO in tetrahedral framework nucleic acids (tFNAs) and synthesis via a one-pot annealing procedure. This construct can significantly knockdown the expression of SPAK and OSR1, along with their downstream ion channel proteins in ChP epithelial cells, thereby leading to a decrease in CSF secretion. Moreover, these findings indicate that TSOs effectively inhibit the M0 to M1 phenotypic switch of ChP macrophages via the MAPK pathways, thus mitigating the cytokine storm. In in vivo post-hemorrhagic hydrocephalus (PHH) models, TSOs significantly reduce CSF secretion rates, alleviate ChP inflammation, and prevent the onset of hydrocephalus. These compelling results highlight the potential of TSOs as a promising therapeutic option for managing hydrocephalus, with significant applications in the future.

A Review of Cerebrospinal Fluid Circulation and the Pathogenesis of Congenital Hydrocephalus

The brain's ventricles are filled with a colorless fluid known as cerebrospinal fluid (CSF). When there is an excessive accumulation of CSF in the ventricles, it can result in high intracranial pressure, ventricular enlargement, and compression of the surrounding brain tissue, leading to potential damage. This condition is referred to as hydrocephalus. Hydrocephalus is classified into two categories: congenital and acquired. Congenital hydrocephalus (CH) poses significant challenges for affected children and their families, particularly in resource-poor countries. Recognizing the psychological and economic impacts is crucial for developing interventions and support systems that can help alleviate the distress and burden faced by these families. As our understanding of CSF production and circulation improves, we are gaining clearer insights into the causes of CH. In this article, we will summarize the current knowledge regarding CSF circulation pathways and the underlying causes of CH. The main causes of CH include abnormalities in the FoxJ1 pathway of ventricular cilia, dysfunctions in the choroid plexus transporter Na+-K+-2Cl- contransporter isoform 1, developmental abnormalities in the cerebral cortex, and structural abnormalities within the brain. Understanding the causes of CH is indeed crucial for advancing research and developing effective treatment strategies. In this review, we will summarize the findings from existing studies on the causes of CH and propose potential research directions to further our understanding of this condition.

Genetic etiologies and diagnostic methods for congenital ventriculomegaly and hydrocephalus: A scoping review

BACKGROUND

Congenital hydrocephalus (CH) is a life-threatening neurological condition that results from an imbalance in production, flow, or absorption of cerebrospinal fluid. Predicted outcomes from in utero diagnosis are frequently unclear. Moreover, conventional treatments consisting primarily of antenatal and postnatal surgeries are often unsuccessful, leading to high mortality rates. Causes of CH can range from secondary insults to germline pathogenic variants, complicating diagnostic processes and treatment outcomes. Currently, an updated summary of CH genetic etiologies in conjunction with clinical testing methodologies is lacking. This review addresses this need by generating a centralized survey of known genetic causes and available molecular tests for CH.

METHODS

The scoping review protocol was registered with the Open Science Framework and followed the Arksey and O'Malley framework and the Joanna Briggs Institute methodology. The Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) was utilized to define search guidelines and screening criteria.

RESULTS

Our survey revealed a high number of genetic etiologies associated with CH, ranging from single gene variants to multifactorial birth defects, and additionally uncovered diagnostic challenges that are further complicated by changes in testing approaches over the years. Furthermore, we discovered that most of the existing literature consists of case reports, underscoring the need for studies that utilize CH patient research cohorts as well as more mechanistic studies.

CONCLUSIONS

The pursuit of such studies will facilitate novel gene discovery while recognizing phenotypic complexity. Addressing these research gaps could ultimately inform evidence-based diagnostic guidelines to improve patient care.

Congenital hydrocephalus diagnosed in a nonagenarian: Case report

Congenital hydrocephalus after peripartum infection usually presents early in life; however, we present a 92-year-old female patient with newly diagnosed hydrocephalus secondary to peripartum infection. Intracranial imaging showed ventriculomegaly, calcifications bilaterally throughout the cerebral hemispheres, and findings suggesting a chronic process. This presentation is most likely to occur in low-resource settings, and given the risks of operation, conservative management was preferred.

Celecoxib attenuates neuroinflammation, reactive astrogliosis and promotes neuroprotection in young rats with experimental hydrocephalus

Hydrocephalus is a neurological condition with altered cerebrospinal fluid flow (CSF). The treatment is surgical and the most commonly used procedure is ventricle-peritoneal shunt. However, not all patients can undergo immediate surgery or achieve complete lesion reversal. Neuroprotective measures are valuable in such cases. It was evaluated whether the use of celecoxib, a selective inhibitor of COX-2, associated or not with ventricular-subcutaneous derivation, could offer benefits to the brain structures affected by experimental hydrocephalus. Seven-day-old male Wistar Hannover rats induced by intracisternal injection of kaolin 15% were used, divided into five groups with ten animals each: intact control (C), untreated hydrocephalus (H), hydrocephalus treated with celecoxib 20 mg/kg intraperitoneal (HTC), hydrocephalus treated with shunt (HTS) and hydrocephalus treated with shunt and celecoxib 20 mg/kg intraperitoneal (HTCS). Celecoxib was administered for 21 consecutive days, starting the day after hydrocephalus induction and continuing until the end of the experimental period. The surgery was performed seven days after inducing hydrocephalus. Multiple assessment methods were used, such as behavioral tests (water maze and open field), histological analysis (hematoxylin and eosin), immunohistochemistry (caspase-3, COX-2, and GFAP), and ELISA analysis of GFAP. The results of the behavioral and memory tests indicated that celecoxib improves the neurobehavioral response. The improvement can be attributed to the reduced neuroinflammation (p < 0.05), and astrogliosis (p < 0.05) in different brain regions. In conclusion, the results suggest that celecoxib holds great potential as an adjuvant neuroprotective drug for the treatment of experimental hydrocephalus.

Cerebrospinal fluid shunt malfunctions: A reflective review

PURPOSE

Pediatric hydrocephalus is a common and challenging condition. To date, the ventriculoperitoneal shunt (VPS) is still the main lifesaving treatment option. Nonetheless, it remains imperfect and is associated with multiple short- and long-term complications. This paper is a reflective review of the current state of the VPS, our knowledge gaps, and the future state of shunts in neurosurgical practice.

METHODS AND RESULTS

The authors' reflections are based on a review of shunts and shunt-related literature.

CONCLUSION

Overall, there is still an urgent need for the neurosurgical community to actively improve current strategies for shunt failures and shunt-related morbidity. The authors emphasize the role of collaborative efforts amongst like-minded clinicians to establish pragmatic approaches to avoid shunt complications.

X-linked hydrocephalus genes: Their proximity to telomeres and high A + T content compared to Parkinson's disease

Proximity to telomeres (i) and high adenine and thymine (A + T) content (ii) are two factors associated with high mutation rates in human chromosomes. We have previously shown that >100 human genes when mutated to cause congenital hydrocephalus (CH) meet either factor (i) or (ii) at 91% matching, while two factors are poorly satisfied in human genes associated with familial Parkinson's disease (fPD) at 59%. Using the sets of mouse, rat, and human chromosomes, we found that 7 genes associated with CH were located on the X chromosome of mice, rats, and humans. However, genes associated with fPD were in different autosomes depending on species. While the contribution of proximity to telomeres in the autosome was comparable in CH and fPD, high A + T content played a pivotal contribution in X-linked CH (43% in all three species) than in fPD (6% in rodents or 13% in humans). Low A + T content found in fPD cases suggests that PARK family genes harbor roughly 3 times higher chances of methylations in CpG sites or epigenetic changes than X-linked genes.

Early postnatal microglial ablation in the Ccdc39 mouse model reveals adverse effects on brain development and in neonatal hydrocephalus

BACKGROUND

Neonatal hydrocephalus is a congenital abnormality resulting in an inflammatory response and microglial cell activation both clinically and in animal models. Previously, we reported a mutation in a motile cilia gene, Ccdc39 that develops neonatal progressive hydrocephalus (prh) with inflammatory microglia. We discovered significantly increased amoeboid-shaped activated microglia in periventricular white matter edema, reduced mature homeostatic microglia in grey matter, and reduced myelination in the prh model. Recently, the role of microglia in animal models of adult brain disorders was examined using cell type-specific ablation by colony-stimulating factor-1 receptor (CSF1R) inhibitor, however, little information exists regarding the role of microglia in neonatal brain disorders such as hydrocephalus. Therefore, we aim to see if ablating pro-inflammatory microglia, and thus suppressing the inflammatory response, in a neonatal hydrocephalic mouse line could have beneficial effects.

METHODS

In this study, Plexxikon 5622 (PLX5622), a CSF1R inhibitor, was subcutaneously administered to wild-type (WT) and prh mutant mice daily from postnatal day (P) 3 to P7. MRI-estimated brain volume was compared with untreated WT and prh mutants P7-9 and immunohistochemistry of the brain sections was performed at P8 and P18-21.

RESULTS

PLX5622 injections successfully ablated IBA1-positive microglia in both the WT and prh mutants at P8. Of the microglia that are resistant to PLX5622 treatment, there was a higher percentage of amoeboid-shaped microglia, identified by morphology with retracted processes. In PLX-treated prh mutants, there was increased ventriculomegaly and no change in the total brain volume was observed. Also, the PLX5622 treatment significantly reduced myelination in WT mice at P8, although this was recovered after full microglia repopulation by P20. Microglia repopulation in the mutants worsened hypomyelination at P20.

CONCLUSIONS

Microglia ablation in the neonatal hydrocephalic brain does not improve white matter edema, and actually worsens ventricular enlargement and hypomyelination, suggesting critical functions of homeostatic ramified microglia to better improve brain development with neonatal hydrocephalus. Future studies with detailed examination of microglial development and status may provide a clarification of the need for microglia in neonatal brain development.

First reports of fetal SMARCC1 related hydrocephalus

The SMARCC1 gene has been involved in congenital ventriculomegaly with aqueduct stenosis but only a few patients have been reported so far, with no antenatal cases, and it is currently not annotated as a morbid gene in OMIM nor in the Human Phenotype Ontology. Most of the reported variants are loss of function (LoF) and are often inherited from unaffected parents. SMARCC1 encodes a subunit of the mSWI/SNF complex and affects the chromatin structure and expression of several genes. Here, we report the two first antenatal cases of SMARCC1 LoF variants detected by Whole Genome Sequencing (WGS). Ventriculomegaly is the common feature in those fetuses. Both identified variants are inherited from a healthy parent, which supports the reported incomplete penetrance of this gene. This makes the identification of this condition in WGS as well as the genetic counseling challenging.

Impaired neurogenesis with reactive astrocytosis in the hippocampus in a porcine model of acquired hydrocephalus

BACKGROUND

Hydrocephalus is a neurological disease with an incidence of 0.3-0.7 per 1000 live births in the United States. Ventriculomegaly, periventricular white matter alterations, inflammation, and gliosis are among the neuropathologies associated with this disease. We hypothesized that hippocampus structure and subgranular zone neurogenesis are altered in untreated hydrocephalus and correlate with recognition memory deficits.

METHODS

Hydrocephalus was induced by intracisternal kaolin injections in domestic juvenile pigs (43.6 ± 9.8 days). Age-matched sham controls received similar saline injections. MRI was performed to measure ventricular volume, and/or hippocampal and perirhinal sizes at 14 ± 4 days and 36 ± 8 days post-induction. Recognition memory was assessed one week before and after kaolin induction. Histology and immunohistochemistry in the hippocampus were performed at sacrifice.

RESULTS

The hippocampal width and the perirhinal cortex thickness were decreased (p < 0.05) in hydrocephalic pigs 14 ± 4 days post-induction. At sacrifice (36 ± 8 days post-induction), significant expansion of the cerebral ventricles was detected (p = 0.005) in hydrocephalic pigs compared with sham controls. The area of the dorsal hippocampus exhibited a reduction (p = 0.035) of 23.4% in the hydrocephalic pigs at sacrifice. Likewise, in hydrocephalic pigs, the percentages of neuronal precursor cells (doublecortin+ cells) and neurons decreased (p < 0.01) by 32.35%, and 19.74%, respectively, in the subgranular zone of the dorsal hippocampus. The percentage of reactive astrocytes (vimentin+) was increased (p = 0.041) by 48.7%. In contrast, microglial cells were found to decrease (p = 0.014) by 55.74% in the dorsal hippocampus in hydrocephalic pigs. There was no difference in the recognition index, a summative measure of learning and memory, one week before and after the induction of hydrocephalus.

CONCLUSION

In untreated juvenile pigs, acquired hydrocephalus caused morphological alterations, reduced neurogenesis, and increased reactive astrocytosis in the hippocampus and perirhinal cortex.

Generation of Periventricular Reactive Astrocytes Overexpressing Aquaporin 4 Is Stimulated by Mesenchymal Stem Cell Therapy

Aquaporin-4 (AQP4) plays a crucial role in brain water circulation and is considered a therapeutic target in hydrocephalus. Congenital hydrocephalus is associated with a reaction of astrocytes in the periventricular white matter both in experimental models and human cases. A previous report showed that bone marrow-derived mesenchymal stem cells (BM-MSCs) transplanted into the lateral ventricles of hyh mice exhibiting severe congenital hydrocephalus are attracted by the periventricular astrocyte reaction, and the cerebral tissue displays recovery. The present investigation aimed to test the effect of BM-MSC treatment on astrocyte reaction formation. BM-MSCs were injected into the lateral ventricles of four-day-old hyh mice, and the periventricular reaction was detected two weeks later. A protein expression analysis of the cerebral tissue differentiated the BM-MSC-treated mice from the controls and revealed effects on neural development. In in vivo and in vitro experiments, BM-MSCs stimulated the generation of periventricular reactive astrocytes overexpressing AQP4 and its regulatory protein kinase D-interacting substrate of 220 kDa (Kidins220). In the cerebral tissue, mRNA overexpression of nerve growth factor (NGF), vascular endothelial growth factor (VEGF), hypoxia-inducible factor-1 (HIF1α), and transforming growth factor beta 1 (TGFβ1) could be related to the regulation of the astrocyte reaction and AQP4 expression. In conclusion, BM-MSC treatment in hydrocephalus can stimulate a key developmental process such as the periventricular astrocyte reaction, where AQP4 overexpression could be implicated in tissue recovery.

Novel concepts in the pathogenesis of hydrocephalus

PURPOSE

Hydrocephalus is a multifactorial neurological disorder and one of the most common neurosurgical conditions characterized by excessive cerebrospinal fluid (CSF) accumulation within the brain's ventricles. It can result in dilatation of the ventricular system caused by the inadequate passage of CSF from its point of production within the ventricles to its point of absorption into the systemic circulation. Recent findings on the genetics and molecular studies of hydrocephalus have the potential to improve treatment and quality of life.

METHODS

Review of literature on the novel studies of the pathogenesis of hydrocephalus.

CONCLUSION

Molecular studies on the pathogenesis of hydrocephalus have provided a means to improve the treatment and follow-up of patients with hydrocephalus.

Bi-allelic variations in CRB2, encoding the crumbs cell polarity complex component 2, lead to non-communicating hydrocephalus due to atresia of the aqueduct of sylvius and central canal of the medulla

Congenital hydrocephalus is a common condition caused by the accumulation of cerebrospinal fluid in the ventricular system. Four major genes are currently known to be causally involved in hydrocephalus, either isolated or as a common clinical feature: L1CAM, AP1S2, MPDZ and CCDC88C. Here, we report 3 cases from 2 families with congenital hydrocephalus due to bi-allelic variations in CRB2, a gene previously reported to cause nephrotic syndrome, variably associated with hydrocephalus. While 2 cases presented with renal cysts, one case presented with isolated hydrocephalus. Neurohistopathological analysis allowed us to demonstrate that, contrary to what was previously proposed, the pathological mechanisms underlying hydrocephalus secondary to CRB2 variations are not due to stenosis but to atresia of both Sylvius Aqueduct and central medullar canal. While CRB2 has been largely shown crucial for apico-basal polarity, immunolabelling experiments in our fetal cases showed normal localization and level of PAR complex components (PKCι and PKCζ) as well as of tight (ZO-1) and adherens (β-catenin and N-Cadherin) junction molecules indicating a priori normal apicobasal polarity and cell-cell adhesion of the ventricular epithelium suggesting another pathological mechanism. Interestingly, atresia but not stenosis of Sylvius aqueduct was also described in cases with variations in MPDZ and CCDC88C encoding proteins previously linked functionally to the Crumbs (CRB) polarity complex, and all 3 being more recently involved in apical constriction, a process crucial for the formation of the central medullar canal. Overall, our findings argue for a common mechanism of CRB2, MPDZ and CCDC88C variations that might lead to abnormal apical constriction of the ventricular cells of the neural tube that will form the ependymal cells lining the definitive central canal of the medulla. Our study thus highlights that hydrocephalus related to CRB2, MPDZ and CCDC88C constitutes a separate pathogenic group of congenital non-communicating hydrocephalus with atresia of both Sylvius aqueduct and central canal of the medulla.

Vanadium improves memory and spatial learning and protects the pyramidal cells of the hippocampus in juvenile hydrocephalic mice

Background

Hydrocephalus is a neurological condition known to cause learning and memory disabilities due to its damaging effect on the hippocampal neurons, especially pyramidal neurons. Vanadium at low doses has been observed to improve learning and memory abilities in neurological disorders but it is uncertain whether such protection will be provided in hydrocephalus. We investigated the morphology of hippocampal pyramidal neurons and neurobehavior in vanadium-treated and control juvenile hydrocephalic mice.

Methods

Hydrocephalus was induced by intra-cisternal injection of sterile-kaolin into juvenile mice which were then allocated into 4 groups of 10 pups each, with one group serving as an untreated hydrocephalic control while others were treated with 0.15, 0.3 and 3 mg/kg i.p of vanadium compound respectively, starting 7 days post-induction for 28 days. Non-hydrocephalic sham controls (n = 10) were sham operated without any treatment. Mice were weighed before dosing and sacrifice. Y-maze, Morris Water Maze and Novel Object Recognition tests were carried out before the sacrifice, the brains harvested, and processed for Cresyl Violet and immunohistochemistry for neurons (NeuN) and astrocytes (GFAP). The pyramidal neurons of the CA1 and CA3 regions of the hippocampus were assessed qualitatively and quantitatively. Data were analyzed using GraphPad prism 8.

Results

Escape latencies of vanadium-treated groups were significantly shorter (45.30 ± 26.30 s, 46.50 ± 26.35 s, 42.99 ± 18.44 s) than untreated group (62.06 ± 24.02 s) suggesting improvements in learning abilities. Time spent in the correct quadrant was significantly shorter in the untreated group (21.19 ± 4.15 s) compared to control (34.15 ± 9.44 s) and 3 mg/kg vanadium-treated group (34.35 ± 9.74 s). Recognition index and mean % alternation were lowest in untreated group (p = 0.0431, p=0.0158) suggesting memory impairments, with insignificant improvements in vanadium-treated groups. NeuN immuno-stained CA1 revealed loss of apical dendrites of the pyramidal cells in untreated hydrocephalus group relative to control and a gradual reversal attempt in the vanadium-treated groups. Astrocytic activation (GFAP stain) in the untreated hydrocephalus group were attenuated in the vanadium-treated groups under the GFAP stain. Pyknotic index in CA1 pyramidal layer of untreated (18.82 ± 2.59) and 0.15mg/kg vanadium-treated groups (18.14 ± 5.92) were significantly higher than control (11.11 ± 0.93; p = 0.0205, p = 0.0373) while there was no significant difference in CA3 pyknotic index across all groups.

Conclusion

Our results suggest that vanadium has a dose-dependent protective effect on the pyramidal cells of the hippocampus and on memory and spatial learning functions in juvenile hydrocephalic mice.

Early Regressive Development of the Subcommissural Organ of Two Human Fetuses with Non-Communicating Hydrocephalus

Hydrocephalus is a central nervous system condition characterized by CSF buildup and ventricular hypertrophy. It is divided into two types: communicative and non-communicating hydrocephalus. Congenital hydrocephalus has been linked to several changes in the subcommissural organ (SCO). However, it is unclear whether these changes occur before or as a result of the hydrocephalic illness. This report presents three cases of human fetuses with hydrocephalus: one non-communicating case, two communicating cases, and two controls. Hematoxylin-Eosin (H&E) or cresyl violet and immunohistochemistry with anti-transthyretin were used to analyze SCO morphological and secretory changes. We conclude that in the cases presented here, there could be an early regression in the SCO of the communicating cases that is not present in the non-communicating case.

Fetal cerebral ventriculomegaly: What do we tell the prospective parents?

Fetal cerebral ventriculomegaly is a relatively common finding, observed during approximately 1% of obstetric ultrasounds. In the second and third trimester, mild (≥10 mm) and severe ventriculomegaly (≥15 mm) are defined according to the measurement of distal lateral ventricles that is included in the routine sonographic examination of central nervous system. A detailed neurosonography and anatomy ultrasound should be performed to detect other associated anomalies in the central nervous system and in other systems, respectively. Fetal MRI might be useful when neurosonography is unavailable or suboptimal. The risk of chromosomal and non-chromosomal genetic disorders associated with ventriculomegaly is high, therefore invasive genetic testing, including microarray, is recommended. Screening for prenatal infections, in particular cytomegalovirus and toxoplasmosis, should also be carried out at diagnosis. The prognosis is determined by the severity of ventriculomegaly and/or by the presence of co-existing abnormalities. Fetal ventriculoamniotic shunting in progressive isolated severe ventriculomegaly is an experimental procedure. After delivery, ventricular-peritoneal shunting or ventriculostomy are the two available options to treat hydrocephalus in specific conditions with similar long-term outcomes. A multidisciplinary fetal neurology team, including perinatologists, geneticists, pediatric neurologists, neuroradiologists and neurosurgeons, can provide parents with the most thorough prenatal counseling. This review outlines the latest evidence on diagnosis and management of pregnancies complicated by fetal cerebral ventriculomegaly.

Liver transplantation in rare late-onset ornithine transcarbamylase deficiency with central nervous system injury: A case report and review of the literature

BACKGROUND

Ornithine transcarbamylase deficiency (OTCD) is a genetic metabolic disease. Its clinical manifestations are mainly central nervous system dysfunction caused by high blood ammonia. Late-onset OTCD combined with central nervous system injury has a poor therapeutic response, which is one of the main factors affecting the prognosis and quality of life of patients. liver transplantation (LT) has gradually become a radical treatment for OTCD, which has achieved good results. However, there is no consensus on the timing of LT and problems of nervous system damage and repair.

METHODS

We report the development of late-onset OTCD with central nervous system injury in an 11-year-old child who received liver transplantation at our transplant center. His first symptoms were nonprojectile vomiting, followed by irritability and disturbance of consciousness, after which the disease progressed rapidly and finally resulted in a coma. After liver transplantation, the child's consciousness returned to normal, muscle strength of the limbs gradually recovered from grade 0 to grade 4, and muscle tone gradually recovered from grade 4 to grade 1, suggesting that the motor nerves had gradually recovered. However, the child is currently mentally retarded, and the language center has not yet fully recovered.At the same time, we made a literature review of OTCD.

CONCLUSION

For OTCD patients with central nervous system injury, liver transplantation can fundamentally solve the problem of ammonia metabolism in the liver and avoids further damage to the central nervous system caused by hyperammonemia. At the same time, children's nervous systems are in the developmental stage when neuroplasticity is greatest. If liver transplantation is performed as soon as possible, nerve repair is still possible.

Hydrocephalus: historical analysis and considerations for treatment

Hydrocephalus is a serious condition that affects patients of all ages, resulting from a multitude of causes. While the etiologies of hydrocephalus are numerous, many of the acute and chronic symptoms of the condition are shared. These symptoms include disorientation and pain (headaches), cognitive and developmental changes, vision and sleep disturbances, and gait abnormalities. This collective group of symptoms combined with the effectiveness of CSF diversion as a surgical intervention for many types of the condition suggest that the various etiologies may share common cellular and molecular dysfunctions. The incidence rate of pediatric hydrocephalus is approximately 0.1-0.6% of live births, making it as common as Down syndrome in infants. Diagnosis and treatment of various forms of adult hydrocephalus remain understudied and underreported. Surgical interventions to treat hydrocephalus, though lifesaving, have a high incidence of failure. Previously tested pharmacotherapies for the treatment of hydrocephalus have resulted in net zero or negative outcomes for patients potentially due to the lack of understanding of the cellular and molecular mechanisms that contribute to the development of hydrocephalus. Very few well-validated drug targets have been proposed for therapy; most of these have been within the last 5 years. Within the last 50 years, there have been only incremental improvements in surgical treatments for hydrocephalus, and there has been little progress made towards prevention or cure. This demonstrates the need to develop nonsurgical interventions for the treatment of hydrocephalus regardless of etiology. The development of new treatment paradigms relies heavily on investment in researching the common molecular mechanisms that contribute to all of the forms of hydrocephalus, and requires the concerted support of patient advocacy organizations, government- and private-funded research, biotechnology and pharmaceutical companies, the medical device industry, and the vast network of healthcare professionals.

Evaluation of the blood neutrophil-to-lymphocyte ratio as a biomarker for meningoencephalitis of unknown etiology in dogs

Background

The neutrophil‐to‐lymphocyte ratio (NLR) has been identified as a biomarker in several inflammatory and autoimmune diseases. Multiple sclerosis (MS) has been found to be associated with changes in the NLR in humans.

Objectives

To examine the diagnostic value of the NLR in meningoencephalitis of unknown etiology (MUE) in dogs.

Animals

Thirty‐eight MUE dogs, 20 hydrocephalic dogs, 10 brain tumor (BT) dogs, 32 idiopathic epilepsy (IE) dogs, and 41 healthy dogs.

Methods

Retrospective study. Medical records were reviewed to identify dogs with a diagnosis of neurologic disease. The NLR was determined in all dogs.

Results

The median NLR was significantly higher in MUE dogs (6.08) than in healthy (1.78, P < .001), IE (2.50, P < .05), and hydrocephalic dogs (1.79, P < .05). The area under the receiver operating characteristic curve of the NLR for differentiation between MUE and healthy dogs was 0.96, and between the MUE dogs and dogs with other forebrain diseases was 0.86. An optimal cutoff of 4.16 for the NLR had a sensitivity of 71.1% and specificity of 83.9% to differentiate the MUE dogs from the dogs with other forebrain diseases.

Conclusions and Clinical Importance

The NLR could be a biomarker for diagnosing MUE and distinguishing it from other intracranial diseases in dogs.

Congenital Brain Malformations: An Integrated Diagnostic Approach

Congenital brain malformations are abnormalities present at birth that can result from developmental disruptions at various embryonic or fetal stages. The clinical presentation is nonspecific and can include developmental delay, hypotonia, and/or epilepsy. An informed combination of imaging and genetic testing enables early and accurate diagnosis and management planning. In this article, we provide a streamlined approach to radiologic phenotyping and genetic evaluation of brain malformations. We will review the clinical workflow for brain imaging and genetic testing with up-to-date ontologies and literature references. The organization of this article introduces a streamlined approach for imaging-based etiologic classification into malformative, destructive, and migrational abnormalities. Specific radiologic ontologies are then discussed in detail, with correlation of key neuroimaging features to embryology and molecular pathogenesis.

An eye on the future for defeating hydrocephalus, ciliary dyskinesia-related hydrocephalus: review article

Congenital hydrocephalus affects approximately one in 1000 newborn children and is fatal in approximately 50% of untreated cases. The currently known management protocols usually necessitate multiple interventions and long-term use of healthcare resources due to a relatively high incidence of complications, and many of them mostly provide a treatment of the effect rather than the cause of cerebrospinal fluid flow reduction or outflow obstruction. Future studies discussing etiology specific hydrocephalus alternative treatments are needed. We systematically reviewed the available literature on the effect of ciliary abnormality on congenital hydrocephalus pathogenesis, to open a discussion on the feasibility of factoring ciliary abnormality in future research on hydrocephalus treatment modalities. Although there are different forms of ciliopathies, we focused in this review on primary ciliary dyskinesia. There is growing evidence of association of other ciliary syndromes and hydrocephalus, such as the reduced generation of multiple motile cilia, which is distinct from primary ciliary dyskinesia. Data for this review were identified by searching PubMed using the search terms 'hydrocephalus,' 'Kartagener syndrome,' 'primary ciliary dyskinesia,' and 'immotile cilia syndrome.' Only articles published in English and reporting human patients were included. Seven studies met our inclusion criteria, reporting 12 cases of hydrocephalus associated with primary ciliary dyskinesia. The patients had variable clinical presentations, genetic backgrounds, and ciliary defects. The ependymal water propelling cilia differ in structure and function from the mucus propelling cilia, and there is a possibility of isolated non-syndromic ependymal ciliopathy causing only hydrocephalus with growing evidence in the literature for the association ependymal ciliary abnormality and hydrocephalus. Abdominal and thoracic situs in children with hydrocephalus can be evaluated, and secondary damage of ependymal cilia causing hydrocephalus in cases with generalized ciliary abnormality can be considered.

Acquired hydrocephalus is associated with neuroinflammation, progenitor loss, and cellular changes in the subventricular zone and periventricular white matter

BACKGROUND

Hydrocephalus is a neurological disease with an incidence of 80-125 per 100,000 births in the United States. Neuropathology comprises ventriculomegaly, periventricular white matter (PVWM) alterations, inflammation, and gliosis. We hypothesized that hydrocephalus in a pig model is associated with subventricular and PVWM cellular alterations and neuroinflammation that could mimic the neuropathology described in hydrocephalic infants.

METHODS

Hydrocephalus was induced by intracisternal kaolin injections in 35-day old female pigs (n = 7 for tissue analysis, n = 10 for CSF analysis). Age-matched sham controls received saline injections (n = 6). After 19-40 days, MRI scanning was performed to measure the ventricular volume. Stem cell proliferation was studied in the Subventricular Zone (SVZ), and cell death and oligodendrocytes were examined in the PVWM. The neuroinflammatory reaction was studied by quantifying astrocytes and microglial cells in the PVWM, and inflammatory cytokines in the CSF.

RESULTS

The expansion of the ventricles was especially pronounced in the body of the lateral ventricle, where ependymal disruption occurred. PVWM showed a 44% increase in cell death and a 67% reduction of oligodendrocytes. In the SVZ, the number of proliferative cells and oligodendrocyte decreased by 75% and 57% respectively. The decrease of the SVZ area correlated significantly with ventricular volume increase. Neuroinflammation occurred in the hydrocephalic pigs with a significant increase of astrocytes and microglia in the PVWM, and high levels of inflammatory interleukins IL-6 and IL-8 in the CSF.

CONCLUSION

The induction of acquired hydrocephalus produced alterations in the PVWM, reduced cell proliferation in the SVZ, and neuroinflammation.

A comparison of Adult and Pediatric Hydrocephalus

Hydrocephalus is a common clinical problem encountered in neurosurgical practice. With greater subspecialisation, pediatric neurosurgery has emerged as a special discipline in several countries. However, in the developing world, which inhabits a large pediatric population, a limited number of neurosurgeons manage all types of hydrocephalus across all ages. There are some essential differences in pediatric and adult hydrocephalus. The spectrum of hydrocephalus of dysgenetic origin in a neonate and that of normal pressure hydrocephalus of the old age has a completely different strategy of management. Endoscopic third ventriculostomy outcomes are known to be closely associated with age at presentation and surgery. Efficacy of alternative pathways of CSF absorption also differs according to age. Managing this disease in various age groups is challenging because of these differences in etiopathology, tempo of the disease, modalities of investigations and various treatment protocols as well as prognosis.

Recovery of the brain after intraventricular hemorrhage

Intraventricular hemorrhage (IVH) remains a major complication of prematurity, worldwide. The severity of IVH is variable, ranging from a tiny germinal matrix bleed to a moderate-to-large ventricular hemorrhage or periventricular hemorrhagic infarction. Survivors with IVH often suffer from hydrocephalus and white matter injury. There is no tangible treatment to prevent post-hemorrhagic cerebral palsy, cognitive deficits, or hydrocephalus in these infants. White matter injury is attributed to blood-induced damage to axons and maturing oligodendrocyte precursors, resulting in reduced myelination and axonal loss. Hydrocephalus results from obstructed CSF circulation by blood clots, increased CSF production, and reduced CSF absorption by lymphatics and arachnoid villi. Several strategies to promote neurological recovery have shown promise in animal models, including the elimination of blood and blood products, alleviating cerebral inflammation and oxidative stress, as well as promoting survival and maturation of oligodendrocyte precursors. The present review integrates novel mechanisms of brain injury in IVH and the imminent therapies to alleviate post-hemorrhagic white matter injury and hydrocephalus in the survivors with IVH.

Profound changes in cerebrospinal fluid proteome and metabolic profile are associated with congenital hydrocephalus

The aetiology of congenital hydrocephalus (cHC) has yet to be resolved. cHC manifests late in rodent gestation, and by 18-22 weeks in human fetuses, coinciding with the start of the major phase of cerebral cortex development. Previously we found that cerebrospinal fluid (CSF) accumulation is associated with compositional changes, folate metabolic impairment and consequential arrest in cortical development. Here, we report a proteomics study on hydrocephalic and normal rat CSF using LC-MSMS and a metabolic pathway analysis to determine the major changes in metabolic and signalling pathways. Non-targeted analysis revealed a proteome transformation across embryonic days 17-20, with the largest changes between day 19 and 20. This provides evidence for a physiological shift in CSF composition and identifies some of the molecular mechanisms unleashed during the onset of cHC. Top molecular regulators that may control the shift in the CSF metabolic signature are also predicted, with potential key biomarkers proposed for early detection of these changes that might be used to develop targeted early therapies for this condition. This study confirms previous findings of a folate metabolic imbalance as well as providing more in depth metabolic analysis and understanding of cHC CSF.

Intraparenchymal hemorrhage after serial ventricular reservoir taps in neonates with hydrocephalus and association with neurodevelopmental outcome at 2 years of age

OBJECTIVE

Decompressing the ventricles with a temporary device is often the initial neurosurgical intervention for preterm infants with hydrocephalus. The authors observed a subgroup of infants who developed intraparenchymal hemorrhage (IPH) after serial ventricular reservoir taps and sought to describe the characteristics of IPH and its association with neurodevelopmental outcome.

METHODS

In this multicenter, case-control study, for each neonate with periventricular and/or subcortical IPH, a gestational age-matched control with reservoir who did not develop IPH was selected. Digital cranial ultrasound (cUS) scans and term-equivalent age (TEA)-MRI (TEA-MRI) studies were assessed. Ventricular measurements were recorded prior to and 3 days and 7 days after reservoir insertion. Changes in ventricular volumes were calculated. Neurodevelopmental outcome was assessed at 2 years corrected age using standardized tests.

RESULTS

Eighteen infants with IPH (mean gestational age 30.0 ± 4.3 weeks) and 18 matched controls were included. Reduction of the ventricular volumes relative to occipitofrontal head circumference after 7 days of reservoir taps was greater in infants with IPH (mean difference -0.19 [95% CI -0.37 to -0.004], p = 0.04). Cognitive and motor Z-scores were similar in infants with and those without IPH (mean difference 0.42 [95% CI -0.17 to 1.01] and 0.58 [95% CI -0.03 to 1.2]; p = 0.2 and 0.06, respectively). Multifocal IPH was negatively associated with cognitive score (coefficient -0.51 [95% CI -0.88 to -0.14], p = 0.009) and ventriculoperitoneal shunt with motor score (coefficient -0.50 [95% CI -1.6 to -0.14], p = 0.02) after adjusting for age at the time of assessment.

CONCLUSIONS

This study reports for the first time that IPH can occur after a rapid reduction of the ventricular volume during the 1st week after the initiation of serial reservoir taps in neonates with hydrocephalus. Further studies on the use of cUS to guide the amount of cerebrospinal fluid removal are warranted.

3D Reconstitution of the Neural Stem Cell Niche: Connecting the Dots

Neural stem cells (NSCs) are important constituents of the nervous system, and they become constrained in two specific regions during adulthood: the subventricular zone (SVZ) and the subgranular zone (SGZ) of the dentate gyrus in the hippocampus. The SVZ niche is a limited-space zone where NSCs are situated and comprised of growth factors and extracellular matrix (ECM) components that shape the microenvironment of the niche. The interaction between ECM components and NSCs regulates the equilibrium between self-renewal and differentiation. To comprehend the niche physiology and how it controls NSC behavior, it is fundamental to develop in vitro models that resemble adequately the physiologic conditions present in the neural stem cell niche. These models can be developed from a variety of biomaterials, along with different biofabrication approaches that permit the organization of neural cells into tissue-like structures. This review intends to update the most recent information regarding the SVZ niche physiology and the diverse biofabrication approaches that have been used to develop suitable microenvironments ex vivo that mimic the NSC niche physiology.

Genetics and Molecular Pathogenesis of Human Hydrocephalus

Hydrocephalus is a neurological disorder with an incidence of 80-125 per 100,000 live births in the United States. The molecular pathogenesis of this multidimensional disorder is complex and has both genetic and environmental influences. This review aims to discuss the genetic and molecular alterations described in human hydrocephalus, from well-characterized, heritable forms of hydrocephalus (e.g., X-linked hydrocephalus from L1CAM variants) to those affecting cilia motility and other complex pathologies such as neural tube defects and Dandy-Walker syndrome. Ventricular zone disruption is one key pattern among congenital and acquired forms of hydrocephalus, with abnormalities in cadherins, which mediate neuroepithelium/ependymal cell junctions and contribute to the pathogenesis and severity of the disease. Given the relationship between hydrocephalus pathogenesis and neurodevelopment, future research should elucidate the genetic and molecular mechanisms that regulate ventricular zone integrity and stem cell biology.

Brain growth after surgical treatment for infant postinfectious hydrocephalus in Sub-Saharan Africa: 2-year results of a randomized trial

OBJECTIVE

Hydrocephalus in infants, particularly that with a postinfectious etiology, is a major public health burden in Sub-Saharan Africa. The authors of this study aimed to determine whether surgical treatment of infant postinfectious hydrocephalus in Uganda results in sustained, long-term brain growth and improved cognitive outcome.

METHODS

The authors performed a trial at a single center in Mbale, Uganda, involving infants (age < 180 days old) with postinfectious hydrocephalus randomized to endoscopic third ventriculostomy plus choroid plexus cauterization (ETV+CPC; n = 51) or ventriculoperitoneal shunt (VPS; n = 49). After 2 years, they assessed developmental outcome with the Bayley Scales of Infant Development, Third Edition (BSID-III), and brain volume (raw and normalized for age and sex) with CT scans.

RESULTS

Eighty-nine infants were assessed for 2-year outcome. There were no significant differences between the two surgical treatment arms in terms of BSID-III cognitive score (p = 0.17) or brain volume (p = 0.36), so they were analyzed together. Raw brain volumes increased between baseline and 2 years (p < 0.001), but this increase occurred almost exclusively in the 1st year (p < 0.001). The fraction of patients with a normal brain volume increased from 15.2% at baseline to 50.0% at 1 year but then declined to 17.8% at 2 years. Substantial normalized brain volume loss was seen in 21.3% patients between baseline and year 2 and in 76.7% between years 1 and 2. The extent of brain growth in the 1st year was not associated with the extent of brain volume changes in the 2nd year. There were significant positive correlations between 2-year brain volume and all BSID-III scores and BSID-III changes from baseline.

CONCLUSIONS

In Sub-Saharan Africa, even after successful surgical treatment of infant postinfectious hydrocephalus, early posttreatment brain growth stagnates in the 2nd year. While the reasons for this finding are unclear, it further emphasizes the importance of primary infection prevention and mitigation strategies along with optimizing the child's environment to maximize brain growth potential.

Neuroophthalmological manifestations of congenital aqueductal stenosis

OBJECTIVE

Congenital aqueductal stenosis (CAS) is a common etiology of hydrocephalus that occurs in a subset of infants and may be linked to an increased incidence of ophthalmological abnormalities and delayed developmental milestones. Although hydrocephalus is common and widely studied, sparse literature exists on patients with isolated (no identifiable genetic link) CAS along with analysis of ophthalmological manifestations. In this study, the authors sought to describe the ophthalmological abnormalities and delayed developmental milestones of patients with isolated CAS.

METHODS

Data of patients with CAS were prospectively entered and monitored in a surgical database maintained by the Department of Neurological Surgery at Children's Hospital of Pittsburgh from January 2005 to October 2016. Patients with a family history of congenital hydrocephalus, positive testing for genetic forms of aqueductal stenosis, other congenital abnormalities suggesting an underlying genetic syndrome, and stenosis/obstruction due to secondary causes were excluded from this study. Prenatal and perinatal history, CSF diversion history, and a variety of outcomes, including ophthalmological deficits and developmental milestones, were collected and analyzed.

RESULTS

A total of 41 patients with isolated CAS were identified, with a mean follow-up duration of 6 years. Among that cohort, 26 patients (63.4%) developed neuroophthalmological complications, which were further stratified. Fourteen patients (34.1%) developed strabismus and 11 (26.8%) developed astigmatism, and 1 patient (2.4%) with papilledema was recorded. Among patients with ophthalmological abnormalities, 76.9% had delayed developmental milestones (p = 0.045).

CONCLUSIONS

Patients with CAS were found to have increased risk of ophthalmological abnormalities requiring correction, along with an increased risk of delayed developmental milestones. Importantly, there was a significant correlation between the development of ophthalmological abnormalities and delayed developmental milestones that was independent of CSF diversion history. Larger patient cohort studies are required to explore whether earlier development of hydrocephalus, as is the case in CAS, causes elevated rates of neurological and ophthalmological complications, and if earlier CSF diversion correlates with improved outcomes.

β-Catenin Deletion in Regional Neural Progenitors Leads to Congenital Hydrocephalus in Mice

Congenital hydrocephalus is a major neurological disorder with high rates of morbidity and mortality; however, the underlying cellular and molecular mechanisms remain largely unknown. Reproducible animal models mirroring both embryonic and postnatal hydrocephalus are also limited. Here, we describe a new mouse model of congenital hydrocephalus through knockout of β-catenin in Nkx2.1-expressing regional neural progenitors. Progressive ventriculomegaly and an enlarged brain were consistently observed in knockout mice from embryonic day 12.5 through to adulthood. Transcriptome profiling revealed severe dysfunctions in progenitor maintenance in the ventricular zone and therefore in cilium biogenesis after β-catenin knockout. Histological analyses also revealed an aberrant neuronal layout in both the ventral and dorsal telencephalon in hydrocephalic mice at both embryonic and postnatal stages. Thus, knockout of β-catenin in regional neural progenitors leads to congenital hydrocephalus and provides a reproducible animal model for studying pathological changes and developing therapeutic interventions for this devastating disease.

Shunting outcomes in communicating hydrocephalus: protocol for a multicentre, open-label, randomised controlled trial

INTRODUCTION

Ventriculoperitoneal shunt (VPS) remains the most widely used methods to treat communicating hydrocephalus. More recently, lumboperitoneal shunt (LPS) has been suggested as a reasonable option in some studies. However, there is lack of high-quality studies comparing these two techniques in order to certain the benefits and harms to use one of these two methods. The purpose of the current study is to determine the effectiveness and safety of the LPS versus the VPS in patients with communicating hydrocephalus.

METHODS AND ANALYSIS

All eligible patients aged 18-90 years with communicating hydrocephalus will be recruited and then randomly allocated into LPS or VPS group in a ratio of 1:1. All patients will be analysed before shunt insertion, at the time of discharge, 1 month, 6 months, 12 months and 24 months postoperatively. The primary outcome measure is the rate of shunt failure at a 2-year follow-up term. The secondary outcomes include Keifer's Hydrocephalus Scale, National Institute of Health Stroke Scale, Glasgow Outcome Scale Extended, Evans index, safety endpoints and cost-effectiveness of hospital stay.

ETHICS AND DISSEMINATION

The study will be performed in compliance with the Declaration of Helsinki (2002) of the World Medical Association. The study was approved by Institutional Review Board of West China Hospital. All patients will be fully informed the potential benefits, potential risks and responsibilities, those who will sign the informed consents once they are included. Preliminary and final results will be published in peer-reviewed journals and presented at national and international congresses.

TRIAL REGISTRATION NUMBER

ChiCTR2100043839.

Nucleo-cytoplasmic shuttling of splicing factor SRSF1 is required for development and cilia function

Shuttling RNA-binding proteins coordinate nuclear and cytoplasmic steps of gene expression. The SR family proteins regulate RNA splicing in the nucleus and a subset of them, including SRSF1, shuttles between the nucleus and cytoplasm affecting post-splicing processes. However, the physiological significance of this remains unclear. Here, we used genome editing to knock-in a nuclear retention signal (NRS) in Srsf1 to create a mouse model harboring an SRSF1 protein that is retained exclusively in the nucleus. Srsf1NRS/NRS mutants displayed small body size, hydrocephalus, and immotile sperm, all traits associated with ciliary defects. We observed reduced translation of a subset of mRNAs and decreased abundance of proteins involved in multiciliogenesis, with disruption of ciliary ultrastructure and motility in cells and tissues derived from this mouse model. These results demonstrate that SRSF1 shuttling is used to reprogram gene expression networks in the context of high cellular demands, as observed here, during motile ciliogenesis.

Cumulative Damage: Cell Death in Posthemorrhagic Hydrocephalus of Prematurity

Globally, approximately 11% of all infants are born preterm, prior to 37 weeks’ gestation. In these high-risk neonates, encephalopathy of prematurity (EoP) is a major cause of both morbidity and mortality, especially for neonates who are born very preterm (<32 weeks gestation). EoP encompasses numerous types of preterm birth-related brain abnormalities and injuries, and can culminate in a diverse array of neurodevelopmental impairments. Of note, posthemorrhagic hydrocephalus of prematurity (PHHP) can be conceptualized as a severe manifestation of EoP. PHHP impacts the immature neonatal brain at a crucial timepoint during neurodevelopment, and can result in permanent, detrimental consequences to not only cerebrospinal fluid (CSF) dynamics, but also to white and gray matter development. In this review, the relevant literature related to the diverse mechanisms of cell death in the setting of PHHP will be thoroughly discussed. Loss of the epithelial cells of the choroid plexus, ependymal cells and their motile cilia, and cellular structures within the glymphatic system are of particular interest. Greater insights into the injuries, initiating targets, and downstream signaling pathways involved in excess cell death shed light on promising areas for therapeutic intervention. This will bolster current efforts to prevent, mitigate, and reverse the consequential brain remodeling that occurs as a result of hydrocephalus and other components of EoP.

Identification of key molecular biomarkers involved in reactive and neurodegenerative processes present in inherited congenital hydrocephalus

BACKGROUND

Periventricular extracellular oedema, myelin damage, inflammation, and glial reactions are common neuropathological events that occur in the brain in congenital hydrocephalus. The periventricular white matter is the most affected region. The present study aimed to identify altered molecular and cellular biomarkers in the neocortex that can function as potential therapeutic targets to both treat and evaluate recovery from these neurodegenerative conditions. The hyh mouse model of hereditary hydrocephalus was used for this purpose.

METHODS

The hyh mouse model of hereditary hydrocephalus (hydrocephalus with hop gait) and control littermates without hydrocephalus were used in the present work. In tissue sections, the ionic content was investigated using energy dispersive X-ray spectroscopy scanning electron microscopy (EDS-SEM). For the lipid analysis, matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) was performed in frozen sections. The expression of proteins in the cerebral white matter was analysed by mass spectrometry. The oligodendrocyte progenitor cells (OPCs) were studied with immunofluorescence in cerebral sections and whole-mount preparations of the ventricle walls.

RESULTS

High sodium and chloride concentrations were found indicating oedema conditions in both the periventricular white matter and extending towards the grey matter. Lipid analysis revealed lower levels of two phosphatidylinositol molecular species in the grey matter, indicating that neural functions were altered in the hydrocephalic mice. In addition, the expression of proteins in the cerebral white matter revealed evident deregulation of the processes of oligodendrocyte differentiation and myelination. Because of the changes in oligodendrocyte differentiation in the white matter, OPCs were also studied. In hydrocephalic mice, OPCs were found to be reactive, overexpressing the NG2 antigen but not giving rise to an increase in mature oligodendrocytes. The higher levels of the NG2 antigen, diacylglycerophosphoserine and possibly transthyretin in the cerebrum of hydrocephalic hyh mice could indicate cell reactions that may have been triggered by inflammation, neurocytotoxic conditions, and ischaemia.

CONCLUSION

Our results identify possible biomarkers of hydrocephalus in the cerebral grey and white matter. In the white matter, OPCs could be reacting to acquire a neuroprotective role or as a delay in the oligodendrocyte maturation.

An Insight into Pathophysiological Features and Therapeutic Advances on Ependymoma

Simple Summary

Although biological information and the molecular classification of ependymoma have been studied, the treatment systems for ependymoma are still insufficient. In addition, because the disease occurs infrequently, it is difficult to obtain sufficient data to conduct large-scale or randomized clinical trials. Therefore, this study is intended to emphasize the importance of understanding its pathological characteristics and prognosis as well as developing treatments for ependymoma through multilateral studies.

Abstract

Glial cells comprise the non-sensory parts of the central nervous system as well as the peripheral nervous system. Glial cells, also known as neuroglia, constitute a significant portion of the mammalian nervous system and can be viewed simply as a matrix of neural cells. Despite being the “Nervenkitt” or “glue of the nerves”, they aptly serve multiple roles, including neuron repair, myelin sheath formation, and cerebrospinal fluid circulation. Ependymal cells are one of four kinds of glial cells that exert distinct functions. Tumorigenesis of a glial cell is termed a glioma, and in the case of an ependymal cell, it is called an ependymoma. Among the various gliomas, an ependymoma in children is one of the more challenging brain tumors to cure. Children are afflicted more severely by ependymal tumors than adults. It has appeared from several surveys that ependymoma comprises approximately six to ten percent of all tumors in children. Presently, the surgical removal of the tumor is considered a standard treatment for ependymomas. It has been conspicuously evident that a combination of irradiation therapy and surgery is much more efficacious in treating ependymomas. The main purpose of this review is to present the importance of both a deep understanding and ongoing research into histopathological features and prognoses of ependymomas to ensure that effective diagnostic methods and treatments can be developed.

Novel therapeutics for hydrocephalus: Insights from animal models

Hydrocephalus is a cerebrospinal fluid physiological disorder that causes ventricular dilation with normal or high intracranial pressure. The current regular treatment for hydrocephalus is cerebrospinal fluid shunting, which is frequently related to failure and complications. Meanwhile, considering that the current nonsurgical treatments of hydrocephalus can only relieve the symptoms but cannot eliminate this complication caused by primary brain injuries, the exploration of more effective therapies has become the focus for many researchers. In this article, the current research status and progress of nonsurgical treatment in animal models of hydrocephalus are reviewed to provide new orientations for animal research and clinical practice.

Genetic etiologies associated with infantile hydrocephalus in a Chinese infantile cohort

BACKGROUND

Infantile hydrocephalus (IHC) is commonly related to other central nervous system diseases, which may have adverse effects on prognosis. The causes of IHC are heterogeneous, and the genetic etiologies are not fully understood. This study aimed to analyze the genetic etiologies of an IHC cohort.

METHODS

The data for 110 IHC patients who had received exome sequencing at the Clinical Genetic Center of the Children's Hospital of Fudan University between 2016 and 2019 were reviewed and analyzed retrospectively. An exome-wide association analysis (EWAS) was performed within this cohort using IHC as the study phenotype.

RESULTS

Of the 110 IHC patients, a pathogenic or likely pathogenic variant was identified in 16 (15%) patients, spanning 13 genes. The genes were mainly associated with metabolic disorders, brain abnormalities, and genetic syndromes. IHC patients who had unclear clinical etiology were more likely to possess a genetic etiology. Based on previous studies and on our EWAS results, ZEB1, SBF2, and GNAI2 were over-represented among IHC patients and might affect the signaling pathways involved in IHC formation.

CONCLUSIONS

Our study showed heterogeneous genetic etiologies in an IHC cohort. It is essential to perform genetic testing on IHC patients who have unclear clinical etiology, and genes associated with metabolic disorders, brain abnormalities, and genetic syndromes should be noted. In addition, when aiming to discover IHC susceptibility genes, genes that might influence the signaling pathways involved in IHC formation should be prioritized.

Airway Adventures of Airtraq: Use of Airtraq Optical Laryngoscope with Adaptor in Infants with Obstructive Hydrocephalus Posted for Endoscopic Third Ventriculostomy

The pediatric airway is a challenge for the anesthetist due to difficulty in adequate assessment, scarcity of management algorithms, lack of precise knowledge regarding incidence, as well as limitations of the various devices, instruments, and video laryngoscopes. We present a case series of infants with obstructive hydrocephalus with anticipated difficult intubation posted for endoscopic third ventriculostomy (ETV) in whom the airway wtas successfully secured using Airtraq optical laryngoscope with adaptor. Although this device has not been widely studied in pediatrics age group, there are different sizes available for use among children. The ease of use, short learning curve, low cost, single use, and successful approach to difficult airway have made it to being the main rescue technique when the initial approach has failed.

A Focus on the Cerebellum: From Embryogenesis to an Age-Related Clinical Perspective

The cerebellum and its functional multiplicity and heterogeneity have been objects of curiosity and interest since ancient times, giving rise to the urge to reveal its complexity. Since the first hypothesis of cerebellar mere role in motor tuning and coordination, much more has been continuously discovered about the cerebellum’s circuitry and functioning throughout centuries, leading to the currently accepted knowledge of its prominent involvement in cognitive, social, and behavioral areas. Particularly in childhood, the cerebellum may subserve several age-dependent functions, which might be compromised in several Central Nervous System pathologies. Overall, cerebellar damage may produce numerous signs and symptoms and determine a wide variety of neuropsychiatric impairments already during the evolutive age. Therefore, an early assessment in children would be desirable to address a prompt diagnosis and a proper intervention since the first months of life. Here we provide an overview of the cerebellum, retracing its morphology, histogenesis, and physiological functions, and finally outlining its involvement in typical and atypical development and the age-dependent patterns of cerebellar dysfunctions.

Evidence for the involvement of caspases in establishing proper cerebrospinal fluid hydrodynamics

A large number of cells undergo apoptosis via caspase activation during and after neural tube closure (NTC) in mammals. Apoptosis is executed by either intrinsic or extrinsic apoptotic pathways, and inhibition of each pathway causes developmental defects around NTC stages, which hampers the physiological roles of apoptosis and caspases after NTC. We generated transgenic mice in which a broad spectrum of caspases could be suppressed in a spatiotemporal manner by pan-caspase inhibitor protein p35 originating from baculovirus. Mice with nervous system-specific expression of p35 (Nestin-Cre (NCre);p35V mice) exhibited postnatal lethality within 1 month after birth. They were born at the expected Mendelian ratio, but demonstrated severe postnatal growth retardation and hydrocephalus. The flow of cerebrospinal fluid (CSF) between the third and fourth ventricles was disturbed, whereas neither stenosis nor abnormality in ciliary morphology was observed in the pathway of CSF flow. Hydrocephalus and growth retardation of NCre;p35V mice were not rescued by the deletion of RIPK3, an essential factor for necroptosis which occurs in the absence of caspase-8 activation during development. The CSF of NCre;p35V mice contained a larger amount of secreted proteins than that of the controls. These findings suggest that the establishment of proper CSF dynamics requires caspase activity during brain development after NTC.

Genes causing congenital hydrocephalus: Their chromosomal characteristics of telomere proximity and DNA compositions

Congenital hydrocephalus (CH) is caused by genetic mutations, but whether factors impacting human genetic mutations are disease-specific remains elusive. Given two factors associated with high mutation rates, we reviewed how many disease-susceptible genes match with (i) proximity to telomeres or (ii) high adenine and thymine (A + T) content in human CH as compared to other disorders of the central nervous system (CNS). We extracted genomic information using a genome data viewer. Importantly, 98 of 108 genes causing CH satisfied (i) or (ii), resulting in >90% matching rate. However, such a high accordance no longer sustained as we checked two factors in Alzheimer's disease (AD) and/or familial Parkinson's disease (fPD), resulting in 84% and 59% matching, respectively. A disease-specific matching of telomere proximity or high A + T content predicts causative genes of CH much better than neurodegenerative diseases and other CNS conditions, likely due to sufficient number of known causative genes (n = 108) and precise determination and classification of the genotype and phenotype. Our analysis suggests a need for identifying genetic basis of both factors before human clinical studies, to prioritize putative genes found in preclinical models into the likely (meeting at least one) and more likely candidate (meeting both), which predisposes human genes to mutations.