Cerebrospinal fluid biomarkers of infantile congenital hydrocephalus

"Various factors affecting the success of the ETV procedure in infants"-an insight via a prospective study

BACKGROUND

Congenital hydrocephalus in infants treated with ETV has variable results in literature. We studied some supposed clinicoradiological parameters which though are considered vital in deciding operative management and have never been thoroughly studied to establish a well-defined association.

AIM AND OBJECTIVE

To evaluate the influence of clinicoradiological profile and intraoperative findings over the outcome of ETV done in infants for congenital hydrocephalus.

MATERIALS AND METHODS

All infants who underwent ETV in King George's Medical University, Lucknow, from January 2019 to February 2020 for congenital hydrocephalus were included. Their clinical, radiological, operative data was gathered. Infants were followed at 1, 3, and 6 months after ETV. ETV success was defined as stabilization of abnormal head growth with resolution of symptoms of raised ICP and no requirement of shunt surgery 6 months post-ETV. All the clinicoradiological and intraoperative factors were statistically correlated with the final outcome.

RESULTS

Forty infants were operated for congenital hydrocephalus during the study period in our institution. Failure rate was higher in children younger than 3 months (p value of 0.04). Increase in head size was present in all 40 cases and bulging anterior fontanelle in 95% cases. Success rate of ETV at 1, 3, and 6 months was 62.5%, 40%, and 35%. Most of failure occurred within 3 months after the procedure. Expiry rate at 1, 3, and 6 month was 15%, 17.5%, and 17.5%. None of the intraoperative findings significantly correlated with the final outcome.

CONCLUSION

ETV can be a luring treatment of congenital hydrocephalus in infants but has limited success rate because of the dependency of procedure on well-formed arachnoid villi for absorption. It also carries minimal risk of fatal complications like CSF leak and meningitis associated with it. Age is the only factor which truly reflects the outcome of the procedure.

The genetic basis of hydrocephalus: genes, pathways, mechanisms, and global impact

Hydrocephalus (HC) is a heterogenous disease characterized by alterations in cerebrospinal fluid (CSF) dynamics that may cause increased intracranial pressure. HC is a component of a wide array of genetic syndromes as well as a secondary consequence of brain injury (intraventricular hemorrhage (IVH), infection, etc.) that can present across the age spectrum, highlighting the phenotypic heterogeneity of the disease. Surgical treatments include ventricular shunting and endoscopic third ventriculostomy with or without choroid plexus cauterization, both of which are prone to failure, and no effective pharmacologic treatments for HC have been developed. Thus, there is an urgent need to understand the genetic architecture and molecular pathogenesis of HC. Without this knowledge, the development of preventive, diagnostic, and therapeutic measures is impeded. However, the genetics of HC is extraordinarily complex, based on studies of varying size, scope, and rigor. This review serves to provide a comprehensive overview of genes, pathways, mechanisms, and global impact of genetics contributing to all etiologies of HC in humans.

The ASPECT Hydrocephalus System: a non-hierarchical descriptive system for clinical use

In patients with hydrocephalus, prognosis and intervention are based on multiple factors. This includes, but is not limited to, time of onset, patient age, treatment history, and obstruction of cerebrospinal fluid flow. Consequently, several distinct hydrocephalus classification systems exist. The International Classification of Diseases (ICD) is universally applied, but in ICD-10 and the upcoming ICD-11, hydrocephalus diagnoses incorporate only a few factors, and the hydrocephalus diagnoses of the ICD systems are based on different clinical measures. As a consequence, multiple diagnoses can be applied to individual cases. Therefore, similar patients may be described with different diagnoses, while clinically different patients may be diagnosed identically. This causes unnecessary dispersion in hydrocephalus diagnostics, rendering the ICD classification of little use for research and clinical decision-making. This paper critically reviews the ICD systems for scientific and functional limitations in the classification of hydrocephalus and presents a new descriptive system. We propose describing hydrocephalus by a system consisting of six clinical key factors of hydrocephalus: A (anatomy); S (symptomatology); P (previous interventions); E (etiology); C (complications); T (time-onset and current age). The "ASPECT Hydrocephalus System" is a systematic, nuanced, and applicable description of patients with hydrocephalus, with a potential to resolve the major issues of previous classifications, thus providing new opportunities for standardized treatment and research.

Promising candidate cerebrospinal fluid biomarkers of seizure disorder, infection, inflammation, tumor, and traumatic brain injury in pediatric patients

Cerebrospinal fluid (CSF) is a dynamic metabolically active body fluid that has many important roles and is commonly analyzed in pediatric patients, mainly to diagnose central nervous system infection and inflammation disorders. CSF components have been extensively evaluated as biomarkers of neurological disorders in adult patients. Circulating microRNAs in CSF are a promising class of biomarkers for various neurological diseases. Due to the complexity of pediatric neurological disorders and difficulty in acquiring CSF samples from pediatric patients, there are challenges in developing CSF biomarkers of pediatric neurological disorders. This review aimed to provide an overview of novel CSF biomarkers of seizure disorders, infection, inflammation, tumor, traumatic brain injuries, intraventricular hemorrhage, and congenital hydrocephalus exclusively observed in pediatric patients.

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.

Cerebrospinal fluid NCAM-1 concentration is associated with neurodevelopmental outcome in post-hemorrhagic hydrocephalus of prematurity

OBJECTIVE

Efforts directed at mitigating neurological disability in preterm infants with intraventricular hemorrhage (IVH) and post hemorrhagic hydrocephalus (PHH) are limited by a dearth of quantifiable metrics capable of predicting long-term outcome. The objective of this study was to examine the relationships between candidate cerebrospinal fluid (CSF) biomarkers of PHH and neurodevelopmental outcomes in infants undergoing neurosurgical treatment for PHH.

STUDY DESIGN

Preterm infants with PHH were enrolled across the Hydrocephalus Clinical Research Network. CSF samples were collected at the time of temporizing neurosurgical procedure (n = 98). Amyloid precursor protein (APP), L1CAM, NCAM-1, and total protein (TP) were compared in PHH versus control CSF. Fifty-four of these PHH subjects underwent Bayley Scales of Infant Development-III (Bayley-III) testing at 15-30 months corrected age. Controlling for false discovery rate (FDR) and adjusting for post-menstrual age (PMA) and IVH grade, Pearson's partial correlation coefficients were used to examine relationships between CSF proteins and Bayley-III composite cognitive, language, and motor scores.

RESULTS

CSF APP, L1CAM, NCAM-1, and TP were elevated in PHH over control at temporizing surgery. CSF NCAM-1 was associated with Bayley-III motor score (R = -0.422, p = 0.007, FDR Q = 0.089), with modest relationships noted with cognition (R = -0.335, p = 0.030, FDR Q = 0.182) and language (R = -0.314, p = 0.048, FDR Q = 0.194) scores. No relationships were observed between CSF APP, L1CAM, or TP and Bayley-III scores. FOHR at the time of temporization did not correlate with Bayley-III scores, though trends were observed with Bayley-III motor (p = 0.0647 and R = -0.2912) and cognitive scores (p = 0.0506 and R = -0.2966).

CONCLUSION

CSF NCAM-1 was associated with neurodevelopment in this multi-institutional PHH cohort. This is the first report relating a specific CSF protein, NCAM-1, to neurodevelopment in PHH. Future work will further investigate a possible role for NCAM-1 as a biomarker of PHH-associated neurological disability.

SOX9-COL9A3-dependent regulation of choroid plexus epithelial polarity governs blood-cerebrospinal fluid barrier integrity

The choroid plexus (CP) is an extensively vascularized neuroepithelial tissue that projects into the brain ventricles. The restriction of transepithelial transport across the CP establishes the blood-cerebrospinal fluid (CSF) barrier that is fundamental to the homeostatic regulation of the central nervous system microenvironment. However, the molecular mechanisms that control this process remain elusive. Here we show that the genetic ablation of Sox9 in the hindbrain CP results in a hyperpermeable blood-CSF barrier that ultimately upsets the CSF electrolyte balance and alters CSF protein composition. Mechanistically, SOX9 is required for the transcriptional up-regulation of Col9a3 in the CP epithelium. The reduction of Col9a3 expression dramatically recapitulates the blood-CSF barrier defects of Sox9 mutants. Loss of collagen IX severely disrupts the structural integrity of the epithelial basement membrane in the CP, leading to progressive loss of extracellular matrix components. Consequently, this perturbs the polarized microtubule dynamics required for correct orientation of apicobasal polarity and thereby impedes tight junction assembly in the CP epithelium. Our findings reveal a pivotal cascade of SOX9-dependent molecular events that is critical for construction of the blood-CSF barrier.

Dental Care for a Child with Congenital Hydrocephalus: A Case Report with 12-Month Follow-Up

Hydrocephalus affects the central nervous system as a result of progressive ventricular dilatation from the accumulation of cerebrospinal fluid in the brain's lateral ventricles. This paper reports on the oral characteristics of a child with congenital hydrocephalus, discusses her complex dental care needs, and presents dental management of this case. Despite the complex and challenging dental needs, this child received dental treatment in a chairside approach without general anesthesia. A thorough knowledge of the patient's medical condition, together with expert clinical skills, was indispensable for managing the child and improving the quality and length of her life.

Relationship Between Oxidative Stress, Tau Level and Antioxidant Mechanisms of the KEAP-1/NRF-2/HO-1 in Children with Hydrocephalus

BACKGROUND

Hydrocephalus is a complex neurologic disorder which has a widespread impact on the central nervous system, and a multifactor disease which effect the CSF dynamics and causes severe neurological impairments in children. The pathophysiology of hydrocephalus is not fully understood. However, increasing evidence suggests that oxidative stress may be an important factor in the pathogenesis of hydrocephalus.

OBJECTIVE

The purpose of this study is to investigate the relationship of KEAP-1/NRF-2/HO-1 pathway, one of the main regulators of the antioxidant system in the hydrocephalus pathology, on oxidative stress and tau protein level.

METHODS

The study included 32 patients with hydrocephalus and 32 healthy controls. KEAP-1, NRF-2, HO-1, TAU, and MPO levels are measured using ELISA method TAS, TOS, Total THIOL colorimetric method.

RESULTS

KEAP-1, TAS, Total THIOL levels were found significantly low in the hydrocephalus group compared to the control group. Nevertheless, it is identified in the hydrocephalus group that the NRF-2, HO-1, TAU, MPO, TOS, and OSI levels were significantly elevated.

CONCLUSION

In conclusion, although KEAP-1/NRF-2/HO-1 pathway is activated in patients with hydrocephalus, it is identified that the antioxidant defense system is insufficient, and ultimately leads to elevated oxidative stress. The elevation in the tau level may be an indicator of oxidative stress induced neurodegenerative damage.

Role of aquaporins in hydrocephalus: what do we know and where do we stand? A systematic review

INTRODUCTION

Glymphatic fluid circulation may be considered the lymphatic system of the brain and the main role of such system seems to be played by aquaporins (AQPs), a family of proteins which regulates water exchange, in particular AQP4 and 1. Alterations of glymphatic fluid circulation through AQPs variations are now emerging as central elements in the pathophysiology of different brain conditions, like hydrocephalus. This systematic review provides an insight about the role of AQPs in hydrocephalus establishment and compensation, investigating their possible role as diagnostic tools or therapeutic targets.

METHODS

PubMed database was screened searching for the relevant existing literature in English language published until February 29th 2020, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement.

RESULTS

A total of 40 articles met the inclusion criteria for our systematic analysis. AQP4 resulted the most studied water channel, followed by AQP1. The changes in cerebrospinal fluid (CSF), brain parenchyma and choroid plexus (CP) in different hydrocephalus type were analyzed. Moreover, important pharmacological interactions regarding AQP and molecules or conditions were discussed. A very interesting result is the general consensus on increase of AQP4 in hydrocephalic patients, unless in patients suffering from idiopathic normal pressure hydrocephalus, where AQP4 shows a tendency in reduction.

CONCLUSION

AQP seem to play a central role in the pathophysiology of hydrocephalus and in its compensation mechanisms. Further studies are required to definitively establish their precise roles and their quantitative changes to allow their utilization as diagnostic tools or therapeutic targets.

Perioperative near-infrared spectroscopy cerebral oxygen saturation in symptomatic pediatric hydrocephalus patients at risk for intracranial hypertension

OBJECTIVE

The lack of a continuous, noninvasive modality for monitoring intracranial pressure (ICP) is a major obstacle in the care of pediatric patients with hydrocephalus who are at risk for intracranial hypertension. Intracranial hypertension can lead to cerebral ischemia and brain tissue hypoxia. In this study, the authors evaluated the use of near-infrared spectroscopy (NIRS) to measure regional cerebral oxygen saturation (rSO2) in symptomatic pediatric patients with hydrocephalus concerning for elevated ICP.

METHODS

The authors evaluated the NIRS rSO2 trends in pediatric patients presenting with acute hydrocephalus and clinical symptoms of intracranial hypertension. NIRS rSO2 values were recorded hourly before and after neurosurgical intervention. To test for significance between preoperative and postoperative values, the authors constructed a linear regression model with the rSO2 values as the outcome and pre- and postsurgery cohorts as the independent variable, adjusted for age and sex, and used the generalized estimating equation method to account for within-subject correlation.

RESULTS

Twenty-two pediatric patients underwent NIRS rSO2 monitoring before and after CSF diversion surgery. The mean durations of NIRS rSO2 recording pre- and postoperatively were 13.95 and 26.82 hours, respectively. The mean pre- and postoperative rSO2 values were 73.84% and 80.65%, respectively, and the adjusted mean difference estimated from the regression model was 5.98% (adjusted p < 0.0001), suggestive of improved cerebral oxygenation after definitive neurosurgical CSF diversion treatment. Postoperatively, all patients returned to baseline neurological status with no clinical symptoms of elevated ICP.

CONCLUSIONS

Cerebral oxygenation trends measured by NIRS in symptomatic pediatric hydrocephalus patients with intracranial hypertension generally improve after CSF diversion surgery.

Neural stem cell therapy of foetal onset hydrocephalus using the HTx rat as experimental model

Foetal onset hydrocephalus is a disease starting early in embryonic life; in many cases it results from a cell junction pathology of neural stem (NSC) and neural progenitor (NPC) cells forming the ventricular zone (VZ) and sub-ventricular zone (SVZ) of the developing brain. This pathology results in disassembling of VZ and loss of NSC/NPC, a phenomenon known as VZ disruption. At the cerebral aqueduct, VZ disruption triggers hydrocephalus while in the telencephalon, it results in abnormal neurogenesis. This may explain why derivative surgery does not cure hydrocephalus. NSC grafting appears as a therapeutic opportunity. The present investigation was designed to find out whether this is a likely possibility. HTx rats develop hereditary hydrocephalus; 30-40% of newborns are hydrocephalic (hyHTx) while their littermates are not (nHTx). NSC/NPC from the VZ/SVZ of nHTx rats were cultured into neurospheres that were then grafted into a lateral ventricle of 1-, 2- or 7-day-old hyHTx. Once in the cerebrospinal fluid, neurospheres disassembled and the freed NSC homed at the areas of VZ disruption. A population of homed cells generated new multiciliated ependyma at the sites where the ependyma was missing due to the inherited pathology. Another population of NSC homed at the disrupted VZ differentiated into βIII-tubulin+ spherical cells likely corresponding to neuroblasts that progressed into the parenchyma. The final fate of these cells could not be established due to the protocol used to label the grafted cells. The functional outcomes of NSC grafting in hydrocephalus remain open. The present study establishes an experimental paradigm of NSC/NPC therapy of foetal onset hydrocephalus, at the etiologic level that needs to be further explored with more analytical methodologies.

Blood Exposure Causes Ventricular Zone Disruption and Glial Activation In Vitro

Intraventricular hemorrhage (IVH) is the most common cause of pediatric hydrocephalus in North America but remains poorly understood. Cell junction-mediated ventricular zone (VZ) disruption and astrogliosis are associated with the pathogenesis of congenital, nonhemorrhagic hydrocephalus. Recently, our group demonstrated that VZ disruption is also present in preterm infants with IVH. On the basis of this observation, we hypothesized that blood triggers the loss of VZ cell junction integrity and related cytopathology. In order to test this hypothesis, we developed an in vitro model of IVH by applying syngeneic blood to cultured VZ cells obtained from newborn mice. Following blood treatment, cells were assayed for N-cadherin-dependent adherens junctions, ciliated ependymal cells, and markers of glial activation using immunohistochemistry and immunoblotting. After 24-48 hours of exposure to blood, VZ cell junctions were disrupted as determined by a significant reduction in N-cadherin expression (p < 0.05). This was also associated with significant decrease in multiciliated cells and increase in glial fibrillary acid protein-expressing cells (p < 0.05). These observations suggest that, in vitro, blood triggers VZ cell loss and glial activation in a pattern that mirrors the cytopathology of human IVH and supports the relevance of this in vitro model to define injury mechanisms.

A Distinct Metabolite Profile Correlates with Neurodegenerative Conditions and the Severity of Congenital Hydrocephalus

In congenital hydrocephalus, cerebrospinal fluid accumulation is associated with increased intracranial pressure (ICP), ischemia/hypoxia, metabolic impairment, neuronal damage, and astrocytic reaction. The aim of this study was to identify whether a metabolite profile revealing tissue responses according to the severity of hydrocephalus can be detected. The hyh mutant mouse used for this study exhibits 2 different forms of hydrocephalus, severe and moderate. In a comprehensive investigation into the 2 progressions of hydrocephalus, mice with severe hydrocephalus were found to have higher ICP and astrocytic reaction. Several metabolites from the mouse brain cortex were analyzed with 1H high-resolution magic angle spinning nuclear magnetic resonance (1H HR-MAS NMR) spectroscopy. A differential profile for metabolites including glutamate and glutamine was found to correlate with the severity of hydrocephalus and can be explained due to differential astrocytic reactions, neurodegenerative conditions, and the presence of ischemia. The glutamate transporter EAAT2 and the metabolite taurine were found to be key histopathological markers of affected parenchymata. In conclusion, a differential metabolite profile can be detected according to the severity of hydrocephalus and associated ICP and therefore can be used to monitor the efficacy of experimental therapies.

Progress in brain barriers and brain fluid research in 2017

The past year, 2017, has seen many important papers published in the fields covered by Fluids and Barriers of the CNS. This article from the Editors highlights some.

Time-to-event analysis of surgically treated posthemorrhagic hydrocephalus in preterm infants: a single-institution retrospective study

PURPOSE

The purpose of this study is to report time points relevant to the neurosurgical management of posthemorrhagic hydrocephalus (PHH).

METHODS

Data were collected retrospectively on 104 preterm infants with intraventricular hemorrhage (IVH) who received neurosurgical intervention for PHH at St. Louis Children's Hospital from 1994 to 2016. Kaplan-Meier curves were constructed for various endpoints.

RESULTS

IVH grade on head ultrasound obtained through routine clinical care was II, III, and IV in 5 (4.8%), 33 (31.7%), and 66 (63.5%) of the patients, respectively. Neither IVH size nor location appeared to affect development of PHH. Days from birth to IVH, ventriculomegaly, temporizing neurosurgical procedure (TNP), and permanent neurosurgical intervention were 2.0 (95% CI 1.7-2.3), 3.0 (2.5-3.5), 24.0 (22.2-25.8), and 101.0 (90.4-111.6), respectively. Grades III and IV IVH did not differ in age at IVH diagnosis (Χ ² (1 d.f.) = 1.32, p = 0.25), ventriculomegaly (Χ ² = 0.73, p = 0.40), TNP (Χ ² = 0.61, p = 0.43), or permanent intervention (Χ ² = 2.48, p = 0.17). Ventricular reservoirs and ventriculosubgaleal shunts were used in 71 (68.3%) and 30 (28.8%), respectively. Eighty (76.9%) of the patients ultimately received a VPS. Five (4.8%) underwent a primary endoscopic third ventriculostomy (ETV), and two (1.9%) had ETV for a revision procedure. Four of the seven ETVs had choroid plexus cauterization.

CONCLUSIONS

Although most infants who develop IVH and ventriculomegaly will do so within a few days of birth, at-risk infants should be observed for at least 4 weeks with serial head ultrasounds to monitor for PHH requiring surgery.