Procollagen I C-propeptide in the cerebrospinal fluid of neonates with posthaemorrhagic hydrocephalus

Revision rates of flow- versus pressure-regulated ventricular shunt valves for the treatment of hydrocephalus in neonates following germinal matrix haemorrhage-a retrospective review

PURPOSE

Neonates with ventricular shunts inserted for hydrocephalus following germinal matrix haemorrhage (GMH) have high rates of shunt revision. The shunt valve plays a key role in regulating the function of the shunt. In this study, we aim to determine if the choice of flow-regulated or pressure-regulated valve used in the initial implantation of a shunt affects the rate of shunt revision.

METHODS

A retrospective cohort comparison study was performed on 34 neonates with hydrocephalus following GMH who underwent placement of a ventricular shunt at the Queensland Children's Hospital from November 2014 to June 2020. The primary outcome examined was the need for revision or replacement of the ventricular shunt after successful initial placement within 2 years of implantation. The secondary outcome examined was the survival time of the shunt.

RESULTS

16 patients had placement of a flow-regulated valve, and 18 patients had placement of a pressure-regulated valve. 14 (87.5%) patients with flow-regulated valves required replacement during the follow-up period. 2 (18.18%) patients with a fixed pressure regulated underwent revision, while 2 (28.57%) programmable pressure-regulated shunts required revision. Patients that had a flow-regulated valve had a statistically significant higher rate of revision compared to those who had a pressure-regulated valve, (87.5% flow vs 22.22% pressure) with a P-value of < 0.001. Valve obstruction was also more common in patients with flow-regulated valves than pressure-regulated valves (4 vs 0) with a P-value of 0.010. Overall mean median survival time was 22.06 months, shunts with flow-regulated valves had a shorter median survival time of 3.19 months compared with over 24 months for pressure-regulated valves with a P-value of < 0.001.

CONCLUSION

Our study suggests that the initial implantation of flow-regulated valves may carry an increased total rate of shunt revision and valve obstruction within the first 2 years following implantation compared to pressure-regulated valves in patients with hydrocephalus following GMH.

Pathophysiologic mechanisms and strategies for the treatment of post-hemorrhagic hydrocephalus of prematurity

PURPOSE

Post-hemorrhagic hydrocephalus (PHH) of prematurity is a devastating pathology. Neurodevelopmental disabilities, including cognitive and motor deficits are very commonly seen among this population. Thus, there is interest to delineate the pathophysiology of PHH to uncover potential therapeutic targets.

METHODS

We performed a systematic review of the current literature on pathophysiological mechanisms and progressive strategies in the management of post-hemorrhagic hydrocephalus of prematurity. Our literature search identified a total of 58 articles pertaining to the pathophysiology, risk factors and management of post-hemorrhagic hydrocephalus.

RESULTS

Presence of high-grade germinal matrix hemorrhage does not always predict PHH and neither does obstruction of pathways seen on ultrasound or MRI scan. We also describe the management options for posthemorrhagic hydrocephalus, including surgical and non-surgical.

CONCLUSION

We conclude that pathogenesis of post-hemorrhagic hydrocephalus of prematurity is clearly multifactorial and definitive prediction of who will eventually develop PHH continues to be elusive.

Factors Associated with Ventriculoperitoneal Shunt Failures in the First 30 Postoperative Days in Pediatric Patients

OBJECTIVE

Placing of a ventriculoperitoneal shunt (VPS) is one of the most common procedures performed by neurosurgeons. Surgical revision of VPS is a significant cause of patient morbidity and mortality. This study was aimed to provide an analysis of factors related to VPS failures in the first 30 postoperative days in a pediatric cohort.

METHODS

This was a retrospective cohort study of 83 pediatric patients (<18 years old), shunted for the first time at a referral care center, between January 2012 and December 2016. Univariate analysis was used to detect potential predictors of VPS failures within the first 30 postoperative days and in the first 6 months of follow-up. Kaplan-Meier survival curves were used to examine the occurrence of VPS failures over time.

RESULTS

During the first 30 postoperative days, VPS failures occurred in 21 patients (25.3%). Intraventricular hemorrhage (IVH) (odds ratio [OR], 4.41; 95% confidence interval [CI], 1.44-13.48), cerebrospinal fluid (CSF) alterations (OR, 5.11; 95% CI, 1.37-19.1), and previous external ventricular drain (EVD) (OR, 7.05; 95% CI, 1.18-41.8) were significantly associated with shunt failure during the first postoperative month. Kaplan-Meier survival analysis showed decreased shunt survival for patients with IVH, both during the first 30 days after surgery (P = 0.005, log-rank), and during the 6 months after surgery (P = 0.005, log-rank).

CONCLUSIONS

In this study, we found that in pediatric patients, IVH was associated with VPS failure within the first 30 postoperative days and decreased shunt survival over time. Further larger prospective randomized studies are needed to better understand these results.

Decorin alleviated chronic hydrocephalus via inhibiting TGF-β1/Smad/CTGF pathway after subarachnoid hemorrhage in rats

Chronic hydrocephalus is one of the severe complications after subarachnoid hemorrhage (SAH). However, there is no efficient treatment for the prevention of chronic hydrocephalus, partially due to poor understanding of underlying pathogenesis, subarachnoid fibrosis. Transforming growth factor-β1(TGF-β1) is a potent fibrogenic factor implicated in wide range of fibrotic diseases. To investigate whether decorin, a natural antagonist for TGF-β1, protects against subarachnoid fibrosis and chronic hydrocephalus after SAH, two-hemorrhage-injection SAH model was conducted in 6-week-old rats. Recombinant human decorin(rhDecorin) (30ug/2ul) was administered before blood injection and on the 10th day after SAH. TGF-β1, p-Smad2/3, connective tissue growth factor (CTGF), collagen I and pro-collagen I c-terminal propeptide were assessed via western blotting, enzyme-linked immunosorbent assay, radioimmunoassay and immunofluorescence. And neurobehavioral tests and Morris water maze were employed to evaluate long-term neurological functions after SAH. We found that SAH induced heightened activation of TGF-β1/Smad/CTGF axis, presenting as a two peak response of TGF-β1 in cerebrospinal fluid, elevation of TGF-β1, p-Smad2/3, CTGF, collagen I in brain parenchyma and pro-collagen I c-terminal propeptide in cerebrospinal fluid, and increased lateral ventricle index. rhDecorin treatment effectively inhibited up-regulation of TGF-β1, p-Smad2/3, CTGF, collagen I and pro-collagen I c-terminal propeptide after SAH. Moreover, rhDecorin treatment significantly reduced lateral ventricular index and incidence of chronic hydrocephalus after SAH. Importantly, rhDecorin improved neurocognitive deficits after SAH. In conclusion, rhDecorin suppresses extracellular matrix accumulation and following subarachnoid fibrosis via inhibiting TGF-β1/Smad/CTGF pathway, preventing development of hydrocephalus and attenuating long-term neurocognitive defects after SAH.

Procollagen Type I C-terminal propeptide, procollagen Type III N-terminal propeptide, hyaluronic acid, and laminin in the cerebrospinal fluid of rats with communicating hydrocephalus

OBJECT

Fibrosis along the route of CSF flow is indicated by the development of hydrocephalus. The changes of fibrosis index might reflect the level of hydrocephalus and even become a diagnostic index of hydrocephalus. The object of this study was to analyze the levels of procollagen Type I C-terminal propeptide (PICP), procollagen Type III N-terminal propeptide (PIIINP), hyaluronic acid (HA), and laminin (LN) and their significance in the CSF of communicating hydrocephalus rat models.

METHODS

Thirty adult Sprague-Dawley rats were randomly divided into 3 groups: hydrocephalus group (20 rats) with intraventricular kaolin injections, sham control group (5 rats) with saline injections, and normal group (5 rats) without any processing. The levels of PICP, PIIINP, HA, and LN in the CSF were detected using ELISA.

RESULTS

Levels of PICP, PIIINP, HA, and LN in the hydrocephalus group were significantly higher than those in the saline control group (p < 0.05). It was revealed by correlation analysis that the increase was positively correlated with the severity of ventricular dilation.

CONCLUSIONS

Results indicated that PICP, PIIINP, HA, and LN continue to rise dramatically in experimental hydrocephalus and may serve as the diagnostic index of hydrocephalus.

Biomarkers in neonatal posthemorrhagic hydrocephalus

Posthemorrhagic hydrocephalus (PHH) is a rare but serious outcome among premature babies in the NICU, with consequences including mortality and severe neurodevelopmental disabilities. The causes of PHH are still not entirely understood, and its prevention and treatment are controversial. Various cerebrospinal fluid biomarkers have been studied in infants with PHH in order to recognize the causes, diagnose brain injury, and predict neurodevelopmental outcomes. This systematic review summarizes studies on biomarkers of extracellular matrix activity, fibrinolysis/coagulation, hypoxia/cell death, and inflammation in the cerebrospinal fluid of infants with PHH.

Infantile posthemorrhagic hydrocephalus

INTRODUCTION

Intraventricular/germinal matrix hemorrhage affects 7-30% of premature neonates, 25-80% of whom (depending on the grade of the hemorrhage) will develop hydrocephalus requiring shunting. Predisposing factors are low birth weight and gestational age.

MATERIAL

There is increasing evidence for the role of TGF-β1 in the pathogenesis of hydrocephalus, but attempts to develop treatment modalities to clear the cerebrospinal fluid (CSF) from blood degradation products have not succeeded so far. Ultrasound is a valuable screening tool for high-risk infants and magnetic resonance imaging is increasingly utilized to differentiate progressive hydrocephalus from ex vacuo ventriculomegaly, evaluate periventricular parenchymal damage, decide on the surgical treatment of hydrocephalus, and follow up these patients in the long term. Treatment of increasing ventriculomegaly and intracranial hypertension in the presence of hemorrhagic CSF can involve a variety of strategies, all with relative drawbacks, aiming to drain the CSF while gaining time for it to clear and the neonate to reach term and become a suitable candidate for shunting. Eventually, patients with progressive ventriculomegaly causing intracranial hypertension, who have reached term and their CSF has cleared from blood products, will need shunting.

CONCLUSION

Cognitive long-term outcome is influenced more by the effect of the initial hemorrhage and other perinatal events and less by hydrocephalus, provided that this has been addressed timely in the early postnatal period. Shunting can have many long-term side effects due to mechanical complications and overdrainage. In particular, patients with posthemorrhagic hydrocephalus are more susceptible to multiloculated hydrocephalus and encysted fourth ventricle, both of which are challenging to treat.

Congenital hydrocephalus and ventriculoperitoneal shunts: influence of etiology and programmable shunts on revisions

OBJECT

Hydrocephalus is a notorious neurosurgical disease that carries the adage "once a shunt always a shunt." This study was conducted to review the treatment results of pediatric hydrocephalus.

METHODS

Pediatric patients who underwent ventriculoperitoneal shunt surgery over the past 14 years were reviewed for shunt revisions. Variables studied included age at shunt placement, revision, or replacement; programmable shunts; infection; obstruction; and diagnosis (congenital, posthemorrhagic, craniospinal dysraphism, and others including trauma, tumors, and infection). Multiple regression analysis methods were used to determine independent risk factors for shunt failure and the number of shunt revisions. The Kaplan-Meier method of survival analysis was used to compare etiologies on the 5-year survival (revision-free) rate and the median 5-year survival time.

RESULTS

A total of 253 patients were studied with an almost equal sex distribution. There were 92 patients with congenital hydrocephalus, 69 with posthemorrhagic hydrocephalus, 48 with craniospinal dysraphism, and 44 with other causes. Programmable shunts were used in 73 patients (other types of shunts were used in 180 patients). A total of 197 patients (78%) underwent revision surgeries due to shunt failures. The mortality rate was 1.6%. Age at first revision, the 5-year survival rate, and the median 5-year survival time were significantly less for both posthemorrhagic and craniospinal dysraphism than for either the congenital or "other" group (p < 0.05). The failure rate and number of revisions were not significantly reduced with programmable shunts compared with either pressure-controlled or no-valve shunts (p > 0.5).

CONCLUSIONS

Posthemorrhagic hydrocephalus and craniospinal dysraphism hydrocephalus had significantly earlier revisions than congenital and other etiologies. Programmable systems did not reduce the failure rate or the average number of shunts revisions.

Intracranial hemorrhage in the preterm infant: understanding it, preventing it

New discoveries in neonatal imaging, cerebral monitoring, and hemodynamics, and greater understanding of inflammatory and genetic mechanisms involved in intracranial hemorrhage (ICH) in the preterm infant are creating opportunities for innovative early detection and prevention approaches. This article covers the spectrum of ICH in the preterm infant, including germinal matrix intraventricular hemorrhage, its complications, and associated phenomena, such as the emerging role of cerebellar hemorrhage. The overall aim of this article is to review the current knowledge of the mechanisms, diagnosis, outcome, and management of preterm ICH; to revisit the origins from which they develop; and to discuss future expectations.

Do drugs that block transforming growth factor beta reduce posthaemorrhagic ventricular dilatation in a neonatal rat model?

AIM

Posthaemorrhagic ventricular dilatation (PHVD) after intraventricular haemorrhage (IVH) remains a significant problem in preterm infants. No treatment has reduced the need for cerebrospinal fluid (CSF) diversion. Considerable evidence implicates transforming growth factor-beta (TGF-beta) in the pathogenesis of PHVD. Pirfenidone and losartan reduce TGF-beta expression and decrease postinflammatory fibrosis in the lungs, kidneys, heart and liver. They have excellent CSF and brain penetration. We hypothesized that administration of pirfenidone or losartan would reduce ventricular dilatation.

METHODS

Ninety-two rat pups underwent intraventricular blood injection on postnatal days (PN) 7 and 8, and were randomised to pirfenidone, losartan or water by gavage for 14 days. Neuromotor testing was carried out twice weekly. After sacrifice at PN21, ventricular area was measured on coronal sections using image-analysis software.

RESULTS

Ninety-five percent of animals undergoing IVH developed PHVD. Ventricular size was not significantly different between animals receiving either drug or water. Neuromotor testing at PN14 was significantly worse in IVH animals than in controls; neither drug improved performance in IVH animals.

CONCLUSION

Drugs that block TGF-beta do not reduce ventricular dilatation in this model. Further study is required to identify other cytokine targets and to determine how PHVD differs from postinflammatory fibrosis in other organs.

Cerebrospinal fluid obstruction and malabsorption in human neonatal hydrocephaly

INTRODUCTION

The pathophysiology involved in human neonatal high-pressure hydrocephalus (HC) includes both cerebrospinal fluid (CSF) malabsorption and obstruction.

OBJECTIVE

The aim was to estimate the relative contribution between CSF malabsorption and obstruction in three different etiological groups of neonatal high-pressure HC by assessment of specific CSF biomarkers indicative of growth factor- and fibrosis-related CSF malabsorption (transforming growth factor beta-1 (TGF beta-1), aminoterminal propeptide of type 1 collagen (PC1NP)].

MATERIALS AND METHODS

Patients were subdivided into three groups. Group A: spina bifida HC (n=12); group B: non-haemorrhagic triventricular HC (n=4); and group C: posthaemorrhagic HC (n=6). To exclude for confounding differences in pro-inflammatory state between the three groups, interleukin-6 (IL-6) CSF concentrations were assessed. Consecutively, the CSF concentrations of TGF beta-1 and PC1NP were compared between the different groups.

RESULTS

Median CSF concentrations of IL-6 were low and did not differ between groups. Median CSF concentrations of PC1NP were significantly lower in group A (median: 180 ng/ml, range 90-808) than in group C (median: 1,060, range 396-1194; p=0.002). TGF beta-1 concentrations were significantly higher in group C (median 355 pg/ml, range 129-843) than in groups A (median 103, range 78-675 pg/ml) and B (median 120 pg/ml, range 91-188; p=0.01 and 0.03, respectively).

CONCLUSIONS

In neonatal posthaemorrhagic HC, high concentrations of malabsorption-related biomarkers contrast with lower concentrations in SB and non-haemorrhagic triventricular HC. During the early development of high pressure HC in SB neonates, CSF biomarkers strongly indicate that CSF obstruction contributes more to the development of HC than malabsorption.

Differential expression of stress response genes in the H-Tx rat model of congenital hydrocephalus

cDNA rat stress microarrays were used to test the general hypothesis that atypical gene expression patterns exist in the brains of Hydrocephalic-Texas (H-Tx) compared to normal Sprague-Dawley (SD) rats on embryonic day 18. Sixty-two percent of the 216 target transcripts were detected in at least 2 of 3 replicates, with maximum mean fold change (MFC) ratios (H-Tx:SD) in Bcl-2-related ovarian killer protein (BOK, 3.07) and peroxisome proliferator-activated receptor-alpha (PPAR-alpha, 0.04). Five (3.73%) of the 134 detected transcripts were elevated and 20 (17.2%) were suppressed more than twofold in H-Tx. MFC ratios for stress response, cytoskeleton-motility, and intracellular transducer-effector-modulator functional classifications were elevated, while MFC ratios for transcription and apoptosis groups were suppressed in H-Tx. K-means clustering revealed several patterns of gene expression with potential biological relevance in apoptosis, intracellular transducer-effector-modulator, metabolism, cell cycle, and stress response transcripts. Multiplex RT-PCR methodology, used to corroborate the cDNA data, captured four distinct temporal expression patterns on embryonic days 16-20 (E16-E20) for HSP27, DnaJ2, HSP47, HSP60, HSP70, HIP, HSP90A, and HSP90beta. The discovery of unique chaperone/heat shock expression profiles in the embryonic brains of H-Tx and SD rats is a powerful step towards the development of novel mechanistic hypotheses in the study of hydrocephalus disorders. This is the first study to associate early stress responses with the differential expression of chaperones/heat shock protein-related genes using the H-Tx model of congenital hydrocephalus.

Vascular endothelial growth factor and transforming growth factor-beta1 are highly expressed in the cerebrospinal fluid of premature infants with posthemorrhagic hydrocephalus

The expression of specific growth factors such as vascular endothelial growth factor (VEGF) and transforming growth factor-beta1 (TGF-beta1) is of importance during brain development and in the pathogenesis of neurodegenerative disorders. VEGF and TGF-beta1 was studied in the cerebrospinal fluid (CSF) of neonates with posthemorrhagic hydrocephalus (PHHC) and nonhemorrhagic hydrocephalus. For determining the interference of inflammatory cytokine interaction with the expression of VEGF and TGF-beta1, IL-6 and IL-10 CSF concentrations were measured. Eighteen neonates who had PHHC and underwent serial reservoir puncture and nine neonates who had congenital nonhemorrhagic hydrocephalus (CHC) and underwent first shunt surgery were included in the study. CSF samples of 11 neonates with lumbar puncture for the exclusion of meningitis served as control subjects. VEGF, TGF-beta1, IL-6, and IL-10 concentrations in the CSF were measured by ELISA technique. VEGF concentrations in the CSF of patients with PHHC were significantly higher (median: 377 pg/mL; range: 101-1301 pg/mL) when compared with patients with CHC (median: 66 pg/mL; range: 3-1991; p < 0.001) and control subjects (median: 2 pg/mL; range: 0-12 pg/mL; p < 0.0001). TGF-beta1 CSF concentrations did not differ from control infants in all groups. Median IL-6 and IL-10 concentrations in the CSF were found to be low in all patient groups. Increased release of VEGF in the CSF of neonates with PHHC and nonhemorrhagic hydrocephalus may serve as an indicator of brain injury from progressive ventricular dilation. TGF-beta1 CSF concentrations are not elevated in the phase of acute fibroproliferative reactions in patients with PHHC.

The pathogenesis of neonatal post-hemorrhagic hydrocephalus

Hydrocephalus after intraventricular hemorrhage (IVH) has emerged as a major complication of preterm birth and is especially problematic to treat. The hydrocephalus is usually ascribed to fibrosing arachnoiditis, meningeal fibrosis and subependymal gliosis, which impair flow and resorption of cerebrospinal fluid (CSF). Recent experimental studies have suggested that acute parenchymal compression and ischemic damage, and increased parenchymal and perivascular deposition of extracellular matrix proteins--probably due at least partly to upregulation of transforming growth factor-beta (TGF-beta)--are further important contributors to the development of the hydrocephalus. IVH is associated with damage to periventricular white matter and the damage is exacerbated by the development of hydrocephalus; combinations of pressure, distortion, ischaemia, inflammation, and free radical-mediated injury are probably responsible. The damage to white matter accounts for the high frequency of cerebral palsy in this group of infants. The identification of mechanisms and mediators of hydrocephalus and white matter damage is leading to the development of new treatments to prevent permanent hydrocephalus and its neurological complications, and to avoid shunt dependence.

Soluble Fas (CD95/Apo-1), soluble Fas ligand, and activated caspase 3 in the cerebrospinal fluid of infants with posthemorrhagic and nonhemorrhagic hydrocephalus

Hydrocephalus may result in loss of tissue associated with neuronal degeneration, axonal damage, and reactive gliosis. The soluble form of the anti-apoptotic regulator Fas (sFas) and the pro-apoptotic factors soluble FasL (sFasL) and activated caspase 3 were studied in the cerebrospinal fluid of infants with hydrocephalus. Fifteen preterm infants with posthemorrhagic hydrocephalus undergoing serial reservoir puncture and seven term or near-term infants with nonhemorrhagic hydrocephalus and shunt surgery were included in the study. Twenty-four age-matched patients with lumbar puncture for the exclusion of meningitis served as controls. Elevated levels of sFas were observed in infants with posthemorrhagic hydrocephalus [median (range), 131 ng/mL (51-279 ng/mL)] and in nonhemorrhagic hydrocephalus [127 ng/mL (35-165 ng/mL)]. sFas concentrations were highest in a subgroup of eight patients with posthemorrhagic hydrocephalus developing periventricular leukomalacia [164 ng/mL (76-227 ng/mL)]. In contrast, in 24 control infants, sFas was low, in 15 cases below detection limit (0.5 ng/mL) and in nine cases, 24 ng/mL (20-43 ng/mL). sFasL and activated caspase 3 did not differ from control infants in all groups of patients. Increased intrathecal release of sFas in the cerebrospinal fluid of infants with hydrocephalus may serve as an indicator of brain injury from progressive ventricular dilatation.

Posthemorrhagic ventricular dilation in the neonate: development and characterization of a rat model

Intraventricular hemorrhage is a common complication of prematurity. Posthemorrhagic ventricular dilation (PHVD) has a high rate of disability and no safe and effective treatment. Its pathogenesis is poorly understood, largely because of the lack of a satisfactory animal model. We have developed a model of neonatal PHVD in the rat. Seven-day-old (P7) Wistar rat pups were given 80-microl injections of citrated rat blood or artificial cerebrospinal fluid (CSF) into alternate lateral ventricles on P7 and P8. Intracranial pressure was monitored and increased briefly by over 8-fold. Some rats received further 10-microl intraventricular injections of India ink on P21. Animals were weighed daily and simple neurologic tests performed. On P21 (or P22 if India ink had been injected), the rats were perfusion-fixed and blocks processed for paraffin histology. Sixty-five percent of pups injected with blood and 50% injected with artificial CSF developed dilated lateral ventricles, with patchy loss of ependyma, marked astrocytic gliosis, and rarefaction of periventricular white matter. India ink injection revealed slow transit of CSF from the dilated lateral ventricles but eventual passage into the subarachnoid space. Pups that had received intraventricular injections but did not develop ventricular dilation nonetheless had lighter brains than littermate controls (p < 0.001). Body weights were not significantly different from controls. Hydrocephalic animals had reduced motor performance as assessed by a grip traction test (p = 0.0002). This model is well suited to studying the pathogenesis of PHVD.