Posthemorrhagic Hydrocephalus Research Articles

Prospects of CSF shunt independence among chronically shunted patients.

CSF shunt placement for hydrocephalus and other etiologies has arguably been the most life-saving intervention in pediatric neurosurgery in the past 6 decades. Yet, chronic shunting remains a source of morbidity for patients of all ages. Neuroendoscopic surgery has made shunt independence possible for newly diagnosed hydrocephalic patients. In this study, we examine the prospects of shunt independence with or without endoscopic third ventriculostomy (ETV) in chronically shunted patients. After IRB approval, a retrospective analysis was completed on patients whose shunt was ligated or removed to achieve shunt independence, with or without ETV. Clinical and imaging data were collected. Eighty-eight patients with CSF shunts had their shunt either ligated or removed, 57 of whom had a concomitant ETV. Original reasons for shunting included: congenital hydrocephalus 20 (23%), post-hemorrhagic hydrocephalus (PHH) of prematurity 14 (16%), aqueductal stenosis 10 (11%), intracranial cyst 8 (9%), tumor 8 (9%), infantile subdural hematomas 8 (9%), myelomeningocele 7 (8%), post-traumatic hydrocephalus 7 (8%) and post-infectious hydrocephalus 6 (7%). The decision to perform a simultaneous ETV was made based on etiology. Forty-nine (56%) patients became shunt independent. The success rate was 46% in the ETV group and 73% in the no ETV group. Using multivariate analysis and Cox Proportional Hazards models, age > 4 months at shunt placement (p = 0.032), no shunt revisions (p = 0.01), select etiologies (p = 0.043), and ETVSS > 70 (in the ETV group) (p = 0.017), were protective factors for shunt independence. Considering the long-term complications of shunting, achieving shunt independence may provide hope for improved quality of life. While this study is underpowered, it provides pilot data identifying factors that predict shunt independence in chronically shunted patients, namely age, absence of prior shunt revision, etiology, and in the ETV group, the ETVSS.

Surgical interventions and short-term outcomes for preterm infants with post-haemorrhagic hydrocephalus: a multicentre cohort study

ObjectiveTo (1) describe differences in types and timing of interventions, (2) report short-term outcomes and (3) describe differences among centres from a large national cohort of preterm infants with post-haemorrhagic...

Attenuation of ventriculomegaly and iron overload after intraventricular hemorrhage by membrane attack complex inhibition.

The pathophysiology of posthemorrhagic hydrocephalus (PHH) is not well understood, but recent data suggest blood components play a significant role. This study aimed to understand the timing of membrane attack complex (MAC) activation after intraventricular hemorrhage (IVH) and the effect of MAC inhibition on PHH development. This study was composed of four parts. First, 24 young adult male rats underwent stereotactic intraventricular injection of autologous blood or saline and MRI on day 1, 3, or 7 after hemorrhage. Second, 18 rats underwent intraventricular injection of saline, autologous blood with aurin tricarboxylic acid (ATA) in vehicle, or autologous blood with vehicle and underwent serial MRI studies on days 1 and 3 after hemorrhage. Third, 12 rats underwent intraventricular injections as above and MRI 2 hours after hemorrhage. Finally, 24 rats underwent the intraventricular injections as above, as well as serial MRI studies on days 1, 7, 14, and 28 after hemorrhage. The MR images were used to calculate ventricular volume and iron deposition. Open field testing was performed to assess functional outcomes. Outcomes on day 28 were reported as a ratio to the animal's baseline values and normalized via log-transformation. Statistical analysis included the Shapiro-Wilk tests for normality and t-tests and 1-way analysis of variance for 2 and 3 groups of continuous variables, respectively. MAC was found within the hematoma 1 day after hemorrhage and persisted until day 7. Administration of ATA resulted in similar intraventricular hematoma volumes compared to vehicle 2 hours after hemorrhage. At 1 and 3 days after hemorrhage, ATA administration resulted in significantly smaller ventricular volumes and less hemolysis within the hematoma than in the vehicle animals. Administration of ATA also resulted in significantly smaller ventriculomegaly and less iron deposition in the periventricular area than in the vehicle rats 28 days after hemorrhage. Functionally, ATA rats were significantly faster, traveled longer distances, and spent less time resting than vehicle rats at 28 days. MAC was activated early and persisted within the hematoma until day 7 after IVH. MAC inhibition attenuated hemolysis in the clot and ventriculomegaly acutely after IVH. One month after hemorrhage, MAC inhibition attenuated ventriculomegaly and iron accumulation and improved functional outcomes.

Ventricular catheter tissue obstruction and shunt malfunction in 9 hydrocephalus etiologies.

Hydrocephalus is a neurological disorder with an incidence of 80-125 per 100,000 births in the United States. The most common treatment, ventricular shunting, has a failure rate of up to 85% within 10 years of placement. The authors aimed to analyze the association between ventricular catheter (VC) tissue obstructions and shunt malfunction for each hydrocephalus etiology. Patient information was collected from 5 hospitals and entered into a REDCap (Research Electronic Data Capture) database by hydrocephalus etiology. The hardware samples were fixed, and each VC tip drainage hole was classified by tissue obstruction after macroscopic analysis. Shunt malfunction data, including shunt revision rate, time to failure, and age at surgery, were correlated with the degree of tissue obstruction in VCs for each etiology. Posthemorrhagic hydrocephalus was the most common etiology (48.9% of total cases). Proximal catheter obstruction was the most frequent cause of hardware removal (90.4%). Myelomeningocele (44% ± 29%), other congenital etiologies (48% ± 40%), hydrocephalus with brain tumors (45% ± 35%), and posthemorrhagic hydrocephalus (41% ± 35%) showed tissue aggregates in more than 40% of the VC holes. A total of 76.8% of samples removed because of symptoms of obstruction showed cellular or tissue aggregates. No conclusive etiological associations were detected when correlating the percentage of holes with tissue for each VC and age at surgery, shunt revision rates, or time between shunt implantation and removal. The proximal VC obstruction was accompanied by tissue aggregates in 76.8% of cases. However, the presence of tissue in the VC did not seem to be associated with hydrocephalus etiology.

Design of a Stem Cell-Based Therapy for Ependymal Repair in Hydrocephalus Associated With Germinal Matrix Hemorrhages.

In preterm birth germinal matrix hemorrhages (GMHs) and the consequent posthemorrhagic hydrocephalus (PHH), the neuroepithelium/ependyma development is disrupted. This work is aimed to explore the possibilities of ependymal repair in GMH/PHH using a combination of neural stem cells, ependymal progenitors (EpPs), and mesenchymal stem cells. GMH/PHH was induced in 4-day-old mice using collagenase, blood, or blood serum injections. PHH severity was characterized 2 weeks later using magnetic resonance, immunofluorescence, and protein expression quantification with mass spectrometry. Ependymal restoration and wall regeneration after stem cell treatments were tested in vivo and in an ex vivo experimental approach using ventricular walls from mice developing moderate and severe GMH/PHH. The effect of the GMH environment on EpP differentiation was tested in vitro. Two-tailed Student t or Wilcoxon-Mann-Whitney U test was used to find differences between the treated and nontreated groups. ANOVA and Kruskal-Wallis tests were used to compare >2 groups with post hoc Tukey and Dunn multiple comparison tests, respectively. PHH severity was correlated with the extension of GMH and ependymal disruption (means, 88.22% severe versus 19.4% moderate). GMH/PHH hindered the survival rates of the transplanted neural stem cells/EpPs. New multiciliated ependymal cells could be generated from transplanted neural stem cells and more efficiently from EpPs (15% mean increase). Blood and TNFα (tumor necrosis factor alpha) negatively affected ciliogenesis in cells committed to ependyma differentiation (expressing Foxj1 [forkhead box J1] transcription factor). Pretreatment with mesenchymal stem cells improved the survival rates of EpPs and ependymal differentiation while reducing the edematous (means, 18% to 0.5% decrease in severe edema) and inflammatory conditions in the explants. The effectiveness of this therapeutical strategy was corroborated in vivo (means, 29% to 0% in severe edema). In GMH/PHH, the ependyma can be restored and edema decreased from either neural stem cell or EpP transplantation in vitro and in vivo. Mesenchymal stem cell pretreatment improved the success of the ependymal restoration.

435 Use of Optic Nerve Sheath Diameter in Extraventricular Drain Weaning in Adults With Post-hemorrhagic Hydrocephalus

INTRODUCTION: Optic nerve sheath diameter (ONSD) can be used as a noninvasive measurement of intercranial pressure. Few studies have evaluated the value of ONSD in predicting the need for ventriculoperitoneal shunt (VPS) placement after development of post-hemorrhagic hydrocephalus (PHH) in adults. METHODS: Adult patients 18 years or older, admitted with intracranial hemorrhage and hydrocephalus requiring EVD placement were included in the study. Demographics were recorded. CT imaging of ONSD was measured (mm) upon initial ED visit before EVD placement (pre-EVD), immediately after successful EVD removal (post-EVD), and if applicable, after EVD removal but immediately before VPS placement. Change in ONSD was calculated and groups were stratified by EVD only patients and EVD+VPS patients. RESULTS: Imaging for 30 patients were successfully retrieved and analyzed for bilateral ONSD values at all timepoints. A statistically significant convergence to a normally distributed mean ONSD was found for both groups (EVD and EVD+VPS). Additionally, a statistically significant increase was found in ONSD between the EVD+VPS group compared to the EVD only group. The EVD only group showed a mean EVD placement time of only 14 days (2 weeks) with an average decrease in ONSD (-0.905mm) compared with the EVD+VPS group who had an increase in ONSD at 14-days (+1.089 mm). CONCLUSIONS: Patients with hydrocephalus due to intracranial hemorrhage who went on to require VPS developed an increase in ONSD despite EVD use while patients who were successfully weaned from the EVD developed a decrease in ONSD. ONSD may be a useful adjunct tool to aid in the process of EVD weaning in this patient population.

Long Noncoding RNA GAS5-Involved Progression of Neonatal Hydrocephalus and Inflammatory Responses.

Intraventricular hemorrhage results in posthemorrhagic hydrocephalus (PHH). Neonatal hydrocephalus remains a challenging disease due to the high failure rate of all management strategies. We evaluated long noncoding RNA growth arrest-specific 5 (GAS5)-mediated network in neonatal hydrocephalus, providing a new direction for the treatment of hydrocephalus. The PHH model was constructed in neonatal rats after intracerebroventricular injection with GAS5, miR-325-3p, and chaperonin containing T-complex protein 1, subunit 8 (CCT8) plasmids, or oligonucleotides. Next, behavioral tests, measurement of serum inflammation, observation of brain tissue pathology, and calculation of hemoglobin and brain water contents were implemented. GAS5, miR-325-3p, and CCT8 expression, in combination with their interactions, was checked. As the results reported, collagenase infusion induced hydrocephalus, impairing neurological function, enhancing inflammation and neuronal apoptosis, and increasing hemoglobin and brain water contents. GAS5 and CCT8 were up-regulated, while miR-325-3p was down-regulated in hydrocephalic rats. Downregulating GAS5/CCT8 or upregulating miR-325-3p could inhibit inflammatory response and improve neurological function in young hydrocephalic rats. GAS5 promotes CCT8 expression through sponge adsorption of miR-325-3p. GAS5 silencing-mediated protections against hydrocephalus were counteracted by CCT8 overexpression. In summary, GAS5 aggravates neonatal hydrocephalus and inflammatory responses in a way of leasing miR-325-3p-involved regulation of CCT8.

Pro-inflammatory cerebrospinal fluid profile of neonates with intraventricular hemorrhage: clinical relevance and contrast with CNS infection.

Interpretation of cerebrospinal fluid (CSF) studies can be challenging in preterm infants. We hypothesized that intraventricular hemorrhage (IVH), post-hemorrhagic hydrocephalus (PHH), and infection (meningitis) promote pro-inflammatory CSF conditions reflected in CSF parameters. Biochemical and cytological profiles of lumbar CSF and peripheral blood samples were analyzed for 81 control, 29 IVH grade 1/2 (IVH1/2), 13 IVH grade 3/4 (IVH3/4), 15 PHH, 20 culture-confirmed bacterial meningitis (BM), and 27 viral meningitis (VM) infants at 36.5 ± 4weeks estimated gestational age. PHH infants had higher (p < 0.02) CSF total cell and red blood cell (RBC) counts compared to control, IVH1/2, BM, and VM infants. No differences in white blood cell (WBC) count were found between IVH3/4, PHH, BM, and VM infants. CSF neutrophil counts increased (p ≤ 0.03) for all groups compared to controls except IVH1/2. CSF protein levels were higher (p ≤ 0.02) and CSF glucose levels were lower (p ≤ 0.003) for PHH infants compared to all other groups. In peripheral blood, PHH infants had higher (p ≤ 0.001) WBC counts and lower (p ≤ 0.03) hemoglobin and hematocrit than all groups except for IVH3/4. Similarities in CSF parameters may reflect common pathological processes in the inflammatory response and show the complexity associated with interpreting CSF profiles, especially in PHH and meningitis/ventriculitis.

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.

Iron homeostasis and post-hemorrhagic hydrocephalus: a review.

Iron physiology is regulated by a complex interplay of extracellular transport systems, coordinated transcriptional responses, and iron efflux mechanisms. Dysregulation of iron metabolism can result in defects in myelination, neurotransmitter synthesis, and neuronal maturation. In neonates, germinal matrix-intraventricular hemorrhage (GMH-IVH) causes iron overload as a result of blood breakdown in the ventricles and brain parenchyma which can lead to post-hemorrhagic hydrocephalus (PHH). However, the precise mechanisms by which GMH-IVH results in PHH remain elusive. Understanding the molecular determinants of iron homeostasis in the developing brain may lead to improved therapies. This manuscript reviews the various roles iron has in brain development, characterizes our understanding of iron transport in the developing brain, and describes potential mechanisms by which iron overload may cause PHH and brain injury. We also review novel preclinical treatments for IVH that specifically target iron. Understanding iron handling within the brain and central nervous system may provide a basis for preventative, targeted treatments for iron-mediated pathogenesis of GMH-IVH and PHH.

Current Status and Associated Factors of Post-Hemorrhagic Hydrocephalus in Infants of 22 to 28 Weeks Gestation With Severe Intraventricular Hemorrhage in Korea: A Nationwide Cohort Study.

Post-hemorrhagic hydrocephalus (PHH), a common complication of severe intraventricular hemorrhage (IVH) in very low birth weight (BW) infants, is associated with significant morbidity and poor neurological outcomes. The objective of this study was to assess the current status of PHH and analyze the risk factors associated with the necessity of treatment for PHH in infants born between 22 and 28 weeks of gestation, specifically those with severe IVH (grade 3 or 4). The analysis was conducted on 1,097 infants who were born between 22-28 gestational weeks and diagnosed with severe IVH, using data from the Korean Neonatal Network. We observed that the prevalence of PHH requiring treatment was 46.3% in infants with severe IVH. Higher rates of mortality, transfer during admission, cerebral palsy, and ventriculoperitoneal shunt after discharge were higher in infants with PHH than in those without PHH. PHH in severe IVH was associated with a higher rate of pulmonary hemorrhage, seizures, and IVH grade 4 in the entire cohort. In addition, it was associated with a lower rate of small for gestational age and chorioamnionitis. In the subgroup analysis, high BW, outborn status, pulmonary hemorrhage, seizure, sepsis, and IVH grade 4 were associated with a higher incidence of PHH between 22 and 25 gestational weeks (GW). In infants born between 26 and 28 GW, a higher incidence of PHH was associated with seizures and IVH grade 4. It is necessary to maintain meticulous monitoring and neurological intervention for infants with PHH not only during admission but also after discharge. In addition, identifying the clinical factors that increase the likelihood of developing PHH from severe IVH is crucial.

A tailored approach to the management of post-haemorrhagic hydrocephalus

PurposeNeuro-endoscopic lavage (NEL) is an increasingly popular intervention for intraventricular haemorrhage (IVH) and post-haemorrhagic hydrocephalus (PHH), with considerable variation in technique dependent on clinician and clinical circumstances. Whilst efforts to standardise the technique are ongoing, this work describes a tertiary centre experience utilising NEL, highlighting potential caveats to standardisation.MethodsA retrospective review of electronic case notes for patients undergoing temporising surgical intervention for IVH between 2012 and 2021 at our centre was performed. Data collected included (i) gestational age, (ii) aetiology of hydrocephalus, (iii) age at time of intervention, (iv) intervention performed, (v) need for permanent CSF diversion, (vi) ‘surgical burden’, i.e. number of procedures following primary intervention, and (vii) wound failure and infection rate. Data was handled in Microsoft Excel and statistical analysis SPSS v27.0Results49 neonates (n = 25 males) were included. Overall mean gestational age was 27 weeks and at intervention 35 + 3 weeks. IVH was the predominant cause of hydrocephalus (93.8%) and primary surgical interventions included insertion of a ventriculosubgaleal shunt (VSGS) in n = 41 (83.6%) patients, NEL in n = 6 (12.2%) patients and insertion of an EVD in n = 2 (4.1%). N = 9 (18.4%) patients underwent NEL at some point during the time interval reviewed; n = 4 (8.2%) received NEL monotherapy and n = 5 (10.2%) also received a VSGS. Rate of conversion to definitive CSF diversion between NEL (n = 8, 88.9%) and VSGS cohorts (n = 37, 92.5%) was not significantly different (p = 0.57), nor between NEL alone (n = 3, 75%) and NEL + VSGS (n = 5, 100%) (p = 0.44). None of the patients that underwent NEL monotherapy had any wound issues or CNS infection as a result of the initial intervention, compared to n = 3 (60%) of those that underwent NEL and implantation of VSGS (p = 0.1).ConclusionBoth NEL and VSGS are effective in temporising hydrocephalus in neonates, occasionally offering a definitive solution in and of themselves. The benefit of dual therapy however remains to be seen, with the addition of VSGS potentially increasing the risk of wound failure in an already vulnerable cohort.

Hydrocephalus in prematurity: does valve choice make a difference?

PurposeExtremely premature neonates diagnosed with post-haemorrhagic hydrocephalus (PHH) are recognised to have particularly poor outcomes. This study assessed the impact of a number of variables on outcomes in this cohort, in particular the choice of shunt valve mechanism.MethodsElectronic case notes were retrospectively reviewed of all premature neonates admitted to our centre for management of hydrocephalus between 2012 and 2021. Data included (i) gestational age, (ii) birth weight, (iii) hydrocephalus aetiology, (iv) surgical intervention, (v) shunt system, (vi) ‘surgical burden’ and (vii) wound failure and infection rate. Data was handled in Microsoft Excel and statistical analysis performed in SPSS v27.0ResultsN = 53 premature hydrocephalic patients were identified (n = 28 (52.8%) female). Median gestational age at birth was 27 weeks (range: 23–36 + 6 weeks), with n = 35 extremely preterm patients and median birth weight of 1.9 kg (range: 0.8–3.6 kg). Total n = 99 programmable valves were implanted (n = 28 (28.3%) de novo, n = 71 (71.2%) revisions); n = 28 (28.3%) underwent n ≥ 1 pressure alterations, after which n = 21 (75%) patients had symptoms improve. In n = 8 patients exchanged from fixed to programmable valves, a mean reduction of 1.9 revisions per patient after exchange was observed (95%CI: 0.36–3.39, p = 0.02). Mean overall shunt survival was 39.5 weeks (95%CI: 30.6–48.5); 33.2 weeks (95%CI: 25.2–41.1) in programmable valves and 35.1 weeks (95%CI: 19.5–50.6) in fixed pressure (p = 0.22) with 12-month survival rates of 25.7% and 24.7%, respectively (p = 0.22). Shorter de novo shunt survival was associated with higher operation count overall (Pearson’s R: − 0.54, 95%CI: − 0.72 to − 0.29, p < 0.01). Wound failure, gestational age and birth weight were significantly associated with shorter de novo shunt survival in a Cox regression proportional hazards model; gestational age had the greatest impact on shunt survival (Exp(B): 0.71, 95%CI: 0.63–0.81, p < 0.01).ConclusionHydrocephalus is especially challenging in extreme prematurity, with a shorter de novo shunt survival associated with higher number of future revisions. Programmable valves provide flexibility with regard to pressure setting, with the potential for fewer shunt revisions in this complex cohort.

Azithromycin reduces hemoglobin-induced innate neuroimmune activation

Neonatal intraventricular hemorrhage (IVH) releases blood products into the lateral ventricles and brain parenchyma. There are currently no medical treatments for IVH and surgery is used to treat a delayed effect of IVH, post-hemorrhagic hydrocephalus. However, surgery is not a cure for intrinsic brain injury from IVH, and is performed in a subacute time frame. Like many neurological diseases and injuries, innate immune activation is implicated in the pathogenesis of IVH. Innate immune activation is a pharmaceutically targetable mechanism to reduce brain injury and post-hemorrhagic hydrocephalus after IVH. Here, we tested the macrolide antibiotic azithromycin, which has immunomodulatory properties, to reduce innate immune activation in an in vitro model of microglial activation using the blood product hemoglobin (Hgb). We then utilized azithromycin in our in vivo model of IVH, using intraventricular blood injection into the lateral ventricle of post-natal day 5 rat pups. In both models, azithromycin modulated innate immune activation by several outcome measures including mitochondrial bioenergetic analysis, cytokine expression and flow cytometric analysis. This suggests that azithromycin, which is safe for neonates, could hold promise for modulating innate immune activation after IVH.

Levels of inflammatory cytokines MCP-1, CCL4, and PD-L1 in CSF differentiate idiopathic normal pressure hydrocephalus from neurodegenerative diseases

BackgroundNeuroinflammatory processes have been suggested to play a role in the pathophysiology of neurodegenerative diseases and post-hemorrhagic hydrocephalus, but have rarely been investigated in patients with idiopathic normal pressure hydrocephalus (iNPH). The aim of this study was to investigate whether levels of inflammatory proteins in CSF are different in iNPH compared to healthy controls and patients with selected neurodegenerative disorders, and whether any of these markers can aid in the differential diagnosis of iNPH.MethodsLumbar CSF was collected from 172 patients from a single center and represented iNPH (n = 74), Alzheimer’s disease (AD) (n = 21), mild cognitive impairment (MCI) due to AD (n = 21), stable MCI (n = 22), frontotemporal dementia (n = 13), and healthy controls (HC) (n = 21). Levels of 92 inflammatory proteins were analyzed using a proximity extension assay. As a first step, differences between iNPH and HC were investigated, and proteins that differed between iNPH and HC were then compared with those from the other groups. The linear regressions were adjusted for age, sex, and plate number.ResultsThree proteins showed higher (MCP-1, p = 0.0013; CCL4, p = 0.0008; CCL11, p = 0.0022) and one lower (PD-L1, p = 0.0051) levels in patients with iNPH compared to HC. MCP-1 was then found to be higher in iNPH than in all other groups. CCL4 was higher in iNPH than in all other groups, except in MCI due to AD. PD-L1 was lower in iNPH compared to all other groups, except in stable MCI. Levels of CCL11 did not differ between iNPH and the differential diagnoses. In a model based on the four proteins mentioned above, the mean area under the receiver operating characteristic curve used to discriminate between iNPH and the other disorders was 0.91.ConclusionsThe inflammatory cytokines MCP-1 and CCL4 are present at higher—and PD-L1 at lower—levels in iNPH than in the other investigated diagnoses. These three selected cytokines may have diagnostic potential in the work-up of patients with iNPH.

In vitro investigation of the effect of proinflammatory cytokines on mouse choroid plexus membrane transporters Ncbe and NKCC1

Intraventricular hemorrhage is a potentially life-threatening condition. Approximately 20% of patients develop posthemorrhagic hydrocephalus with increased ventricular volume and intracranial pressure. Hydrocephalus develops partially due to increased secretion of cerebrospinal fluid by the choroid plexus. During hemorrhage a multitude of factors are released into the cerebrospinal fluid. Many of these have been implicated in the hypersecretion. In this study, we have investigated the isolated effect of inflammatory components, on the abundance of two membrane transporters involved in cerebrospinal fluid secretion by the choroid plexus: the Na+-dependent Cl−/HCO3− exchanger, Ncbe, and the Na+, K+, 2Cl− cotransporter, NKCC1. We have established a primary choroid plexus epithelial cell culture from 1 to 7 days old mouse pups. Seven days after seeding, the cells formed a monolayer. The cells were treated with either tumor necrosis factor alpha (TNFα), interleukin 1 beta (IL-1β), or interleukin 6 (IL-6) to mimic inflammation. The data show that treatment with TNFα, and IL-1β only transiently increased NKCC1 abundance whereas the effect on Ncbe abundance was a transient decrease. IL-6 however significantly increased NKCC1 (242%), the phosphorylated NKCC1 (147%), as well as pSPAK (406%) abundance, but had no effect on Ncbe. This study suggests that the inflammatory pathway involved in hypersecretion primarily is mediated by activation of basolateral receptors in the choroid plexus, mainly facilitated by IL-6. This study highlights the complexity of the pathophysiological circumstances occurring during intraventricular hemorrhage.

Minocycline attenuates hydrocephalus and inhibits iron accumulation, ependymal damage and epiplexus cell activation after intraventricular hemorrhage in aged rats

Intracerebral hemorrhage is primarily a disease of the elderly and it is frequently accompanied by intraventricular hemorrhage (IVH) which can lead to posthemorrhagic hydrocephalus and poor prognosis. Red blood cell iron has been implicated in brain injury after cerebral hemorrhage. The current study examined using T2* magnetic resonance imaging (MRI) to detect periventricular iron deposition after IVH and investigated the effects of minocycline on hydrocephalus in an aged rat IVH model. It had three parts. In part 1, male aged rats received a 200 μl injection of saline or autologous blood into the lateral ventricle and were euthanized at day 14. In parts 2 and 3, aged IVH rats were treated with vehicle or minocycline and euthanized at day 7 or 14. Rats underwent MRI to quantify hydrocephalus and iron deposition followed by brain histology and immunohistochemistry. Periventricular iron overload was found after IVH using T2* MRI and confirmed by histology. IVH also caused ventricular wall damage and increased the number of CD68(+) choroid plexus epiplexus cells. Minocycline administration reduced iron deposition and ventricular volume at days 7 and 14 after IVH, as well as ventricle wall damage and epiplexus cell activation. In summary, IVH-induced hydrocephalus is associated with periventricular iron deposition, ependymal damage and choroid plexus epiplexus cell activation in aged rats. Minocycline attenuated those effects and might be a potential treatment for posthemorrhagic hydrocephalus in the elderly.

CSF hypersecretion versus impaired CSF absorption in posthemorrhagic hydrocephalus: a systematic review.

The molecular mechanisms underlying development of posthemorrhagic hydrocephalus (PHH) remain elusive. The aim of this systematic review was to evaluate existing literature on increased CSF secretion and impaired CSF absorption as pathogenic contributors to CSF accumulation in neonatal and adult PHH. The systematic review was conducted in accordance with the PRISMA guidelines. Relevant studies published before March 11th, 2023, were identified from PubMed and reference lists. Studies were screened for eligibility using predefined inclusion and exclusion criteria. Data from eligible studies were extracted and potential sources of bias were evaluated. Nineteen studies quantified CSF production rates and/or CSF absorption capacity in human patients with PHH or animals with experimentally induced PHH. Increased CSF production was reported as early as 24 h and as late as 28 days post ictus in six out of eight studies quantifying CSF production rates in animals with experimentally induced PHH. Impaired CSF absorption was reported in all four studies quantifying CSF absorption capacity in human patients with PHH and in seven out of nine studies quantifying CSF absorption capacity in animals with experimentally induced PHH. Impaired CSF absorption was reported as early as 30 min and as late as 10 months post ictus. The pathological CSF accumulation in PHH likely arises from a combination of increased CSF secretion and impaired CSF absorption, which may manifest at different time scales following a hemorrhagic event. Emergent evidence on increased CSF secretion by the choroid plexus may herald a paradigm shift in our understanding of PHH.

Posthemorrhagic hydrocephalus management in patients with necrotizing enterocolitis: a monocentric experience.

Posthemorrhagic hydrocephalus (PHH) and necrotizing enterocolitis (NEC) are two comorbidities associated with prematurity. The management of patients with both conditions is complex and it is necessary to intercept them to avoid meningitis and multilocular hydrocephalus. In a single-center retrospective study, we analyzed 19 patients with NEC and PHH admitted from 2012 to 2022. We evaluated perinatal, imaging, and NEC-related data. We documented shunt obstruction and infection and deaths within 12months of shunt insertion. We evaluated 19 patients with NEC and PHH. Six cases (31.58%) were male, the median birth weight was 880g (650-3150), and the median gestational age was 26weeks (23-38). Transfontanellar ultrasound was performed on 18 patients (94.74%) and Levine classification system was used: 3 cases (15.79%) had a mild Levine index, 11 cases (57.89%) had moderate, and 5 cases (26.32%) were graded as severe. Magnetic resonance showed intraventricular hemorrhage in 14 cases (73.68%) and ventricular dilatation in 15 cases (78.95%). The median age at shunt insertion was 24days (9-122) and the median length of hospital stay was 120days (11-316). Sepsis was present in 15 cases (78.95%). NEC-related infection involved the peritoneal shunt in 4 patients and 3 of them had subclinical NEC. At the last follow-up, 6 (31.58%) patients presented with psychomotor delay. No deaths were reported. Although recognition of subclinical NEC is challenging, the insertion of a ventriculoperitoneal shunt is not recommended in these cases and alternative treatments should be considered to reduce the risk of meningitis and shunt malfunction.

Distinct Cerebrospinal Fluid Lipid Signature in Patients with Subarachnoid Hemorrhage-Induced Hydrocephalus.

Patients with subarachnoid hemorrhage (SAH) may develop posthemorrhagic hydrocephalus (PHH), which is treated with surgical cerebrospinal fluid (CSF) diversion. This diversion is associated with risk of infection and shunt failure. Biomarkers for PHH etiology, CSF dynamics disturbances, and potentially subsequent shunt dependency are therefore in demand. With the recent demonstration of lipid-mediated CSF hypersecretion contributing to PHH, exploration of the CSF lipid signature in relation to brain pathology is of interest. Despite being a relatively new addition to the omic's landscape, lipidomics are increasingly recognized as a tool for biomarker identification, as they provide a comprehensive overview of lipid profiles in biological systems. We here employ an untargeted mass spectroscopy-based platform and reveal the complete lipid profile of cisternal CSF from healthy control subjects and demonstrate its bimodal fluctuation with age. Various classes of lipids, in addition to select individual lipids, were elevated in the ventricular CSF obtained from patients with SAH during placement of an external ventricular drain. The lipidomic signature of the CSF in the patients with SAH suggests dysregulation of the lipids in the CSF in this patient group. Our data thereby reveal possible biomarkers present in a brain pathology with a hemorrhagic event, some of which could be potential future biomarkers for hypersecretion contributing to ventriculomegaly and thus pharmacological targets for pathologies involving disturbed CSF dynamics.