Posthaemorrhagic ventricular dilatation

Aquaporin 4 Mediates the Effect of Iron Overload on Hydrocephalus After Intraventricular Hemorrhage

BACKGROUND

Iron overload plays an important role in hydrocephalus development following intraventricular hemorrhage (IVH). Aquaporin 4 (AQP4) participates in the balance of cerebrospinal fluid secretion and absorption. The current study investigated the role of AQP4 in the formation of hydrocephalus caused by iron overload after IVH.

METHODS

There were three parts to this study. First, Sprague-Dawley rats received an intraventricular injection of 100 µl autologous blood or saline control. Second, rats had IVH and were treated with deferoxamine (DFX), an iron chelator, or vehicle. Third, rats had IVH and were treated with 2-(nicotinamide)-1,3,4-thiadiazole (TGN-020), a specific AQP4 inhibitor, or vehicle. Rats underwent T2-weighted and T2* gradient-echo magnetic resonance imaging to assess lateral ventricular volume and intraventricular iron deposition at 7, 14, and 28 days after intraventricular injection and were then euthanized. Real-time quantitative polymerase chain reaction, western blot analysis, and immunofluorescence analyses were conducted on the rat brains to evaluate the expression of AQP4 at different time points. Hematoxylin and eosin-stained brain sections were obtained to assess the ventricular wall damage on day 28.

RESULTS

Intraventricular injection of autologous blood caused a significant ventricular dilatation, iron deposition, and ventricular wall damage. There was increased AQP4 mRNA and protein expression in the periventricular tissue in IVH rats through day 7 to day 28. The DFX treatment group had a lower lateral ventricular volume and less intraventricular iron deposition and ventricular wall damage than the vehicle-treated group after IVH. The expression of AQP4 protein in periventricular tissue was also inhibited by DFX on days 14 and 28 after IVH. The use of TGN-020 attenuated hydrocephalus development after IVH and inhibited the expression of AQP4 protein in the periventricular tissue between day 14 and day 28 without a significant effect on intraventricular iron deposition or ventricular wall damage.

CONCLUSIONS

AQP4 located in the periventricular area mediated the effect of iron overload on hydrocephalus after IVH.

Drainage, Irrigation, and Fibrinolytic Therapy (DRIFT) for Adult Intraventricular Hemorrhage Using IRRAflow® Self-Irrigating Catheter

Intraventricular hemorrhage (IVH) is a devastating neurosurgical condition associated with high rates of morbidity and mortality. It can occur as the result of several pathologies and typically presents with mental status changes, neurologic deficits, seizures, headaches, and decreased Glasgow Coma Scale score. These patients are often treated with placement of an external ventricular drain, which helps decrease the clot burden; however, they commonly clot off leading to multiple exchanges. We present a case in which drainage, irrigation, and fibrinolytic (DRIFT) therapy using IRRAflow® (IRRAS) irrigating catheter was used to treat a patient with severe IVH secondary to aneurysmal subarachnoid hemorrhage.

Human Cord Blood Derived Unrestricted Somatic Stem Cells Restore Aquaporin Channel Expression, Reduce Inflammation and Inhibit the Development of Hydrocephalus After Experimentally Induced Perinatal Intraventricular Hemorrhage

Intraventricular hemorrhage (IVH) is a severe complication of preterm birth associated with cerebral palsy, intellectual disability, and commonly, accumulation of cerebrospinal fluid (CSF). Histologically, IVH leads to subependymal gliosis, fibrosis, and disruption of the ependymal wall. Importantly, expression of aquaporin channels 1 and 4 (AQP1 and AQP4) regulating respectively, secretion and absorption of cerebrospinal fluids is altered with IVH and are associated with development of post hemorrhagic hydrocephalus. Human cord blood derived unrestricted somatic stem cells (USSCs), which we previously demonstrated to reduce the magnitude of hydrocephalus, as having anti-inflammatory, and beneficial behavioral effects, were injected into the cerebral ventricles of rabbit pups 18 h after glycerol-induced IVH. USSC treated IVH pups showed a reduction in ventricular size when compared to control pups at 7 and 14 days (both, P < 0.05). Histologically, USSC treatment reduced cellular infiltration and ependymal wall disruption. In the region of the choroid plexus, immuno-reactivity for AQP1 and ependymal wall AQP4 expression were suppressed after IVH but were restored following USSC administration. Effects were confirmed by analysis of mRNA from dissected choroid plexus and ependymal tissue. Transforming growth factor beta (TGF-β) isoforms, connective tissue growth factor (CTGF) and matrix metalloprotease-9 (MMP-9) mRNA, as well as protein levels, were significantly increased following IVH and restored towards normal with USSC treatment (P < 0.05). The anti-inflammatory cytokine Interleukin-10 (IL-10) mRNA was reduced in IVH, but significantly recovered after USSC injection (P < 0.05). In conclusion, USSCs exerted anti-inflammatory effects by suppressing both TGF-β specific isoforms, CTGF and MMP-9, recovered IL-10, restored aquaporins expression towards baseline, and reduced hydrocephalus. These results support the possibility of the use of USSCs to reduce IVH consequences in prematurity.

Germinal Matrix-Intraventricular Hemorrhage: A Tale of Preterm Infants

Germinal matrix-intraventricular hemorrhage (GM-IVH) is a common intracranial complication in preterm infants, especially those born before 32 weeks of gestation and very-low-birth-weight infants. Hemorrhage originates in the fragile capillary network of the subependymal germinal matrix of the developing brain and may disrupt the ependymal lining and progress into the lateral cerebral ventricle. GM-IVH is associated with increased mortality and abnormal neurodevelopmental outcomes such as posthemorrhagic hydrocephalus, cerebral palsy, epilepsy, severe cognitive impairment, and visual and hearing impairment. Most affected neonates are asymptomatic, and thus, diagnosis is usually made using real-time transfontanellar ultrasound. The present review provides a synopsis of the pathogenesis, grading, incidence, risk factors, and diagnosis of GM-IVH in preterm neonates. We explore brief literature related to outcomes, management interventions, and pharmacological and nonpharmacological prevention strategies for GM-IVH and posthemorrhagic hydrocephalus.

A comprehensive review of therapeutic targets that induce microglia/macrophage-mediated hematoma resolution after germinal matrix hemorrhage

Currently, there is no effective treatment for germinal matrix hemorrhage and intraventricular hemorrhage (GMH-IVH), a common and often fatal stroke subtype in premature infants. Secondary brain injury after GMH-IVH is known to involve blood clots that contribute to inflammation and neurological deficits. Furthermore, the subsequent blood clots disrupt normal cerebrospinal fluid circulation and absorption after GMH-IVH, contributing to posthemorrhagic hydrocephalus (PHH). Clinically, GMH-IVH severity is graded on a I to IV scale: Grade I is confined to the germinal matrix, grade II includes intraventricular hemorrhage, grade III includes intraventricular hemorrhage with extension into dilated ventricles, and grade IV includes intraventricular hemorrhage with extension into dilated ventricles as well as parenchymal hemorrhaging. GMH-IVH hematoma volume is the best prognostic indicator, where patients with higher grades have worsened outcomes. Various preclinical studies have shown that rapid hematoma resolution quickly ameliorates inflammation and improves neurological outcomes. Current experimental evidence identifies alternatively activated microglia as playing a pivotal role in hematoma clearance. In this review, we discuss the pathophysiology of GMH-IVH in the development of PHH, microglia/macrophage's role in the neonatal CNS, and established/potential therapeutic targets that enhance M2 microglia/macrophage phagocytosis of blood clots after GMH-IVH.

Dexamethasone does not prevent hydrocephalus after severe intraventricular hemorrhage in newborn rats

The aim of this study was done to determine whether dexamethasone treatment prevents posthemorrhagic hydrocephalus (PHH) development and attenuates brain damage after severe IVH in newborn rats. Severe IVH was induced by injecting; 100 μL of blood into each lateral ventricle of postnatal day 4 (P4) Sprague-Dawley rats. Dexamethasone was injected intraperitoneally into rat pups at a dose of 0.5 mg/kg, 0.3 mg/kg, and 0.1 mg/kg on P5, P6, and P7, respectively. Serial brain magnetic resonance imaging and behavioral function tests, such as the negative geotaxis test and the rotarod test, were performed. On P32, brain tissues were obtained for histological and biochemical analyses. Dexamethasone treatment significantly improved the severe IVH-induced increase in the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling-positive cells, glial fibrillary acidic protein-positive astrocytes and ED-1 positive microglia, and the decrease in myelin basic protein. IVH reduced a survival of 71%, that showed a tendency to improve to 86% with dexamethasone treatment, although the result was not statistically significant. However, dexamethasone failed to prevent the progression to PHH and did not significantly improve impaired behavioral tests. Similarly, dexamethasone did not decrease the level of inflammatory cytokines such as interleukin (IL) -1α and ß, IL-6, and tumor necrosis factor-α after severe IVH. Despite its some neuroprotective effects, dexamethasone failed to improve the progress of PHH and impaired behavioral tests after severe IVH.

The choroid plexus as a site of damage in hemorrhagic and ischemic stroke and its role in responding to injury

While the impact of hemorrhagic and ischemic strokes on the blood–brain barrier has been extensively studied, the impact of these types of stroke on the choroid plexus, site of the blood-CSF barrier, has received much less attention. The purpose of this review is to examine evidence of choroid plexus injury in clinical and preclinical studies of intraventricular hemorrhage, subarachnoid hemorrhage, intracerebral hemorrhage and ischemic stroke. It then discusses evidence that the choroid plexuses are important in the response to brain injury, with potential roles in limiting damage. The overall aim of the review is to highlight deficiencies in our knowledge on the impact of hemorrhagic and ischemic strokes on the choroid plexus, particularly with reference to intraventricular hemorrhage, and to suggest that a greater understanding of the response of the choroid plexus to stroke may open new avenues for brain protection.

Emergency uncross-matched blood transfusions in a tertiary neonatal unit

AIM

To determine the neonatal incidence, indications and outcomes following transfusions with emergency uncross-matched O-negative blood.

METHODS

A five-year retrospective review in a single tertiary neonatal unit was conducted. The blood transfusion laboratory's database was analysed for all infants who had received an emergency released blood transfusion (ERBT) between January 2010 and December 2014.

RESULTS

We calculated a total ERBT rate of 0.91 per 1000 live births (39/42 657) and a rate of 0.43 per 1000 in infants >34 weeks' gestation (18/41 637). A rate of 0.14 per 1000 births (6/42 657) received an ERBT as part of newborn stabilisation despite almost half of our infant cohort having intrapartum haemorrhages (n = 18, 46%). One-third (13/39) of all infants who were transfused died. Outcome varied depending on underlying aetiology, gestation and birthweight. The highest mortality was in preterm infants weighing <1000 g, of whom 70% died.

CONCLUSION

This study establishes an ERBT rate of <1 per 1000 births, and 0.14 per 1000 infants received an ERBT as part of newborn delivery room stabilisation. ERBTs are associated with a high mortality rate. This study highlights the need for further research and guidelines that clarify the role of ERBTs in newborn stabilisations.

Mesenchymal Stem Cells: The Magic Cure for Intraventricular Hemorrhage?

Severe intraventricular hemorrhage (IVH) remains a major cause of mortality and long-term neurologic morbidities in premature infants, despite recent advances in neonatal intensive care medicine. Several preclinical studies have demonstrated the beneficial effects of mesenchymal stem cell (MSC) transplantation in attenuating brain injuries resulting from severe IVH. Because there currently exists no effective intervention for severe IVH, the therapeutic potential of MSC transplantation in this intractable and devastating disease is creating excitement in this field. This review summarizes recent progress in stem cell research for treating neonatal brain injury due to severe IVH, with a particular focus on preclinical data concerning important issues, such as mechanism of protective action and determining optimal source, route, timing, and dose of MSC transplantation, and on the translation of these preclinical study results to a clinical trial.

Introduction of percutaneous-tunneled transfontanellar external ventricular drainage in the management of hydrocephalus in extremely low-birth-weight infants

OBJECTIVE Hydrocephalus treatment in extremely low-birth-weight (ELBW) infants still represents a challenge for the pediatric neurosurgeon, particularly when the patient weighs far less than 1000 g. In such cases, the benefits in terms of neurological outcome following early treatment do not always outweigh the surgical risks, especially considering the great difference in the surgical risk before patient weight increases. To assess the efficacy and reliability of a percutaneous-tunneled, transfontanellar external ventricular drain (PTTEVD) in ELBW infants, the authors started a new protocol for the early surgical treatment of hydrocephalus. METHODS Ten cases of posthemorrhagic hydrocephalus (PHH) in ELBW infants (5 cases < 700 g, range for all cases 550-1000 g) were treated with a PTTEVD that was implanted at bedside as the first measure in a stepwise approach. RESULTS The average duration of the procedure was 7 minutes, and there was no blood loss. The drain remained in place for an average of 24 days (range 8-45 days). In all cases early control of the hydrocephalus was achieved. One patient had a single episode of CSF leakage (due to insufficient CSF removal). In another patient Enterococcus in the CSF sample was detected the day after abdominal surgery with ileostomy (infection resolved with intrathecal vancomycin). One patient died of Streptococcus sepsis, a systemic infection existing prior to drain placement that never resolved. One patient had Pseudomonas aeruginosa sepsis prior to drain insertion; a PTTEVD was implanted, the infection resolved, and the hydrocephalus was treated in the same way as with a traditional EVD, while the advantages of a quick, minimally invasive, bedside procedure were maintained. Once a patient reached 1 kg in weight, when necessary, a ventriculoperitoneal shunt was implanted and the PTTEVD was removed. CONCLUSIONS The introduction of PTTEVD placement in our standard protocol for the management of PHH has proved to be a wise option for small patients.

Clinical Experience of Infantile Posthemorrhagic Hydrocephalus Treated with Ventriculo-Peritoneal Shunt

Objective

Infantile posthemorrhagic hydrocephalus (IPHH) is the most common cause of infantile acquired hydrocephalus. We present and discuss our experience of treatment of six IPHH patients treated by a ventriculo-peritoneal (VP) shunt.

Methods

Six preterm infants treated by a VP shunt due to germinal matrix hemorrhage and hydrocephalus were included in our study. External ventricular drainage (EVD) was performed in patients with symptomatic ventricular dilatation, and a VP shunt was placed in the case of no improvement of the ventricular index despite several rounds of EVD. Radiographic findings and surgical outcomes were analyzed retrospectively.

Results

Four patients were male and two were female. Mean gestational age was 25 weeks and mean weight at birth was 868.3 g. One patient had a Papile grade II (16.7%) hemorrhage, three had a grade III (50%) hemorrhage, and two had a grade IV (33.3%) hemorrhage. EVD complications (one case of ventriculitis and one case of a ventricular abscess) occurred in two patients. VP shunt complications occurred in two patients (33.3%). Three cases had an isolated 4th ventricle; two of these cases had a VP shunt placed whereas the other case had a VP shunt placed in addition to aqueductoplasty using a neuroendoscope. At the last follow-up, three of the six patients had severe neurodevelopmental delay, two had mild neurodevelopmental delay, and one had normal development status.

Conclusion

In our study, although it is difficult to present the significant result for management of IPHH, we think that varied efforts are required to treat IPHH patients.

Mechanisms of hydrocephalus after intraventricular haemorrhage in adults

Intraventricular haemorrhage (IVH) is defined as the eruption of blood in the cerebroventricular system and occurs mostly secondary to intracerebral haemorrhage (ICH) in adults. Hydrocephalus is a severe complication of IVH that can serve as an independent predictor of increased mortality. In this mini-review, we focus on the mechanisms of hydrocephalus after adult IVH, including blood-clot blockage, barrier impairment, inflammation and blood components, and attempt to reconcile the current research findings into a unified framework. We expect our theoretical framework to help guide future clinical and basic research leading to improved monitoring and intervention for IVH and subsequent hydrocephalus.

Intraventricular Hemorrhage and Post Hemorrhagic Hydrocephalus among Very-Low-Birth-Weight Infants in Korea

Here, we aimed to evaluate the incidence and mortality of intraventricular hemorrhage (IVH) and post-hemorrhagic hydrocephalus (PHH) among very-low-birth-weight (VLBW) infants in Korea and assess the associated factors of PHH. This cohort study used prospectively collected data from the Korean Neonatal Network (KNN). Among 2,386 VLBW infants in the KNN database born between January 2013 and June 2014, 63 infants who died without brain ultrasonography results were excluded. Maternal demographics and neonatal clinical characteristics were assessed. The overall incidence of IVH in all the VLBW infants was 42.2% (987 of 2,323), while those of IVH grade 1, 2, 3, and 4 were 25.1%, 7.0%, 4.8%, and 5.5%, respectively. The incidence and severity of IVH showed a negatively correlating trend with gestational age and birth weight. PHH developed in 0%, 3.5%, 36.1%, and 63.8% of the surviving infants with IVH grades 1, 2, 3, and 4, respectively. Overall, in the VLBW infants, the IVH-associated mortality rate was 1.0% (24/2,323). Only IVH grade severity was proven to be an associated with PHH development in infants with IVH grades 3-4. This is the first Korean national report of IVH and PHH incidences in VLBW infants. Further risk factor analyses or quality improvement studies to reduce IVH are warranted.

Mesenchymal stem cells transplantation for neuroprotection in preterm infants with severe intraventricular hemorrhage

Severe intraventricular hemorrhaging (IVH) in premature infants and subsequent posthemorrhagic hydrocephalus (PHH) causes significant mortality and life-long neurological complications, including seizures, cerebral palsy, and developmental retardation. However, there are currently no effective therapies for neonatal IVH. The pathogenesis of PHH has been mainly explained by inflammation within the subarachnoid spaces due to the hemolysis of extravasated blood after IVH. Obliterative arachnoiditis, induced by inflammatory responses, impairs cerebrospinal fluid (CSF) resorption and subsequently leads to the development of PHH with ensuing brain damage. Increasing evidence has demonstrated potent immunomodulating abilities of mesenchymal stem cells (MSCs) in various brain injury models. Recent reports of MSC transplantation in an IVH model of newborn rats demonstrated that intraventricular transplantation of MSCs downregulated the inflammatory cytokines in CSF and attenuated progressive PHH. In addition, MSC transplantation mitigated the brain damages that ensue after IVH and PHH, including reactive gliosis, cell death, delayed myelination, and impaired behavioral functions. These findings suggest that MSCs are promising therapeutic agents for neuroprotection in preterm infants with severe IVH.

Recommendations regarding imaging of the central nervous system in fetuses and neonates

An abnormal presentation of the central nervous system in a fetus during a screening examination is an indication for extended diagnosis, the aim of which is to explain the character of such an anomaly (a congenital defect, destructive effect of intrauterine infection or abnormality with reasons that are difficult to explain). Knowledge of normal development sequence of the fetal brain, which is discussed in this paper, is the basis for correct interpretation of imaging findings. Together with the increase in survival of preterm neonates, a high risk of early brain damage is still a problem in this extremely immature population. Therefore, imaging examinations become necessary. The paper presents intrauterine and postnatal risk factors of early brain damage as well as classification of such lesions, of hemorrhagic and hypoxic-ischemic etiology. The diagnosis of the cerebellum damage, which is currently believed to be a significant cause of autism, is emphasized. The evolution of lesions over time is also presented. Moreover, the elements of diagnosis important for prognosis are stressed. The standards of imaging examinations of the central nervous system include the schedule of ultrasound examinations and provide indications for extended diagnosis with the use of magnetic resonance imaging.

Ventriculoperitoneal shunt as a primary neurosurgical procedure in newborn posthemorrhagic hydrocephalus: report of a series of 47 shunted patients

PURPOSE

Intraventricular hemorrhage is the most common cause of infantile acquired hydrocephalus. Our objective is to determine if the implantation of ventriculoperitoneal shunt in posthemorrhagic hydrocephalus as a primary and definitive neurosurgical treatment, with no previous temporary procedures, would decrease complication rates with good functional outcomes.

METHODS

Two hundred seventy-one patients with germinal matrix hemorrhage were diagnosed at the Carlos Haya Hospital between 2003 and 2010. Forty-seven patients underwent ventriculoperitoneal shunt after developing symptomatic hydrocephalus. The minimum weight required for shunt implantation was 1,500 g. We recorded complications related to the surgical procedure and analyzed functional state with a self-developed four-grade scale.

RESULTS

One hundred thirty-nine (51.3 %) patients with intraventricular hemorrhage developed ventricular dilatation, but only 47 patients (17.34 %) needed shunting. In seven cases, temporary neurosurgical procedures were performed, but in all of them, this was followed by ventriculoperitoneal shunt implantation. The infection rate was 4.25 %, and shunt obstruction rate was 4.25 %. More than 80 % of patients were classified as good or excellent functional state. Mean follow-up period was 38.75 months (SD, 27.09; range, 1-102 months).

CONCLUSIONS

Ventriculoperitoneal shunting as a primary neurosurgical treatment in posthemorrhagic hydrocephalus would decrease surgical morbidity with good functional outcome.

Mechanisms of hydrocephalus after neonatal and adult intraventricular hemorrhage

Intraventricular hemorrhage (IVH) is a cause of significant morbidity and mortality and is an independent predictor of a worse outcome in intracerebral hemorrhage (ICH) and germinal matrix hemorrhage (GMH). IVH may result in both injuries to the brain as well as hydrocephalus. This paper reviews evidence on the mechanisms and potential treatments for IVH-induced hydrocephalus. One frequently cited theory to explain hydrocephalus after IVH involves obliteration of the arachnoid villi by microthrombi with subsequent inflammation and fibrosis causing CSF outflow obstruction. Although there is some evidence to support this theory, there may be other mechanisms involved, which contribute to the development of hydrocephalus. It is also unclear whether the causes of acute and chronic hydrocephalus after hemorrhage occur via different mechanisms; mechanical obstruction by blood in the former, and inflammation and fibrosis in the latter. Management of IVH and strategies for prevention of brain injury and hydrocephalus are areas requiring further study. A better understanding of the pathogenesis of hydrocephalus after IVH, may lead to improved strategies to prevent and treat post-hemorrhagic hydrocephalus.

Case series: fractional anisotropy along the trajectory of selected white matter tracts in adolescents born preterm with ventricular dilation

This case series assesses white matter microstructure in 3 adolescents born preterm with nonshunted ventricular dilation secondary to intraventricular hemorrhage. Subjects (ages 12-17 years, gestational age 26-29 weeks, birth weight 825-1624 g) were compared to 3 full-term controls (13-17 years, 39-40 weeks, 3147-3345 g) and 3 adolescents born preterm without ventricular dilation (10-13 years, 26-29 weeks, 630-1673 g). Tractography using a 2 region of interest method reconstructed the following white matter tracts: superior longitudinal/arcuate fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, and corticospinal tract. Subjects showed increased fractional anisotropy and changes in the pattern of fractional anisotropy along the trajectory of tracts adjacent to the lateral ventricles. Tensor shape at areas of increased fractional anisotropy demonstrated increased linear anisotropy at the expense of planar and spherical anisotropy. These findings suggest increased axonal packing density and straightening of fibers secondary to ventricular enlargement.

Intrauterine grade IV intraventricular hemorrhage in a full-term infant leading to hydrocephalus

INTRODUCTION

Peri/intraventricular hemorrhage (PIVH) is more often seen in premature neonates and can lead to posthemorrhagic hydrocephalus, characterized by high mortality rate and neurodevelopmental delay.

CASE REPORT

We report a case of in utero PIVH in a full-term neonate, which led to hydrocephalus. The infant developed at 8 months of gestational age intracerebral/intraventricular hemorrhage at the regions of the left basal ganglia and thalamus with significant intraventricular extension and ventriculomegaly, which was diagnosed with fetal MR scan, and progressed post partum to active multiloculated hydrocephalus. At the age of 3 months, the infant was operated on with endoscopic fenestration of the ventricular septations at the left side and ventriculoperitoneal shunt insertion at the right side. A follow-up MR scan after 4 months showed improvement of the ventriculomegaly and the multiloculated hydrocephalus. Up to a period of 6 months follow up, there have been no shunt-related problems.

DISCUSSION

The complications of a grade IV intraventricular hemorrhage are well documented in premature infants. It is difficult to know to what extent these apply equally to full-term infants with intraventricular hemorrhage. Ventricular hemorrhage is very rarely reported in full-term neonates, and even more rarely in the intrauterine period.

Implantation of Ommaya reservoir in extremely low weight premature infants with posthemorrhagic hydrocephalus: a cautious option

OBJECTIVE

This study aims to evaluate effects and complications of the implantation of Ommaya reservoir in premature infants with posthemorrhagic hydrocephalus (PHH).

METHODS

The effects and complications of the implantation of Ommaya reservoir in seven premature infants with PHH were retrospectively analyzed. Intracapsular puncture of the reservoir was performed for draining cerebrospinal fluid.

RESULTS

Seven extremely low-weight premature infants with PHH (birthweight less than 1,000 g) were treated with the placement of an Ommaya reservoir. Ommaya reservoirs in five infants were removed, but were retained in two infants. Two premature infants had to undergo ventriculoperitoneal (VP) shunt. Postsurgical major complications (including skin dehiscence, cerebrospinal fluid (CSF) infection, ventricular hemorrhage, and CSF leak) occurred in 57% of all patients. Three infants of skin dehiscence and CSF leak occurred. Two infants of CSF infection occurred, as well as one clinically significant secondary hemorrhage. Six infants survived, and one died.

CONCLUSION

The implantation of Ommaya reservoir is a cautious option of treating low-weight premature infants with PHH because of a relatively high complication rate. However, VP shunt surgery may be avoided in some infants.

Pathological conditions involving extracellular hemoglobin: molecular mechanisms, clinical significance, and novel therapeutic opportunities for α(1)-microglobulin

Hemoglobin (Hb) is the major oxygen (O(2))-carrying system of the blood but has many potentially dangerous side effects due to oxidation and reduction reactions of the heme-bound iron and O(2). Extracellular Hb, resulting from hemolysis or exogenous infusion, is shown to be an important pathogenic factor in a growing number of diseases. This review briefly outlines the oxidative/reductive toxic reactions of Hb and its metabolites. It also describes physiological protection mechanisms that have evolved against extracellular Hb, with a focus on the most recently discovered: the heme- and radical-binding protein α(1)-microglobulin (A1M). This protein is found in all vertebrates, including man, and operates by rapidly clearing cytosols and extravascular fluids of heme groups and free radicals released from Hb. Five groups of pathological conditions with high concentrations of extracellular Hb are described: hemolytic anemias and transfusion reactions, the pregnancy complication pre-eclampsia, cerebral intraventricular hemorrhage of premature infants, chronic inflammatory leg ulcers, and infusion of Hb-based O(2) carriers as blood substitutes. Finally, possible treatments of these conditions are discussed, giving a special attention to the described protective effects of A1M.

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.

Unusual case of 'trapped fourth ventricle' in a child with posthemorrhagic hydrocephalus--lessons learnt

In most of the children with posthemorrhagic hydrocephalus (PHH), multidisciplinary follow-up is performed, with the focus on consequences of prematurity, cerebral palsy (CP) and hydrocephalus. A large fourth ventricle is common in these children but imaging performed in order to document ventricles and tissue damage is not oriented to exclude coexisting rare pathologies. We report a 3-year-old child with spastic CP, secondary to prematurity and PHH. A ventriculoperitoneal shunt was inserted at the age of 2 months. On follow-up imaging the child demonstrated well-drained supratentorial ventricles with a persistent large fourth ventricle. Because of a neurological change in spasticity and new-onset torticollis, a repeat MRI was performed, suggesting a cystic, nonenhancing lesion of the fourth ventricle. The surgical exploration revealed a large dermoid of the fourth ventricle. We analyze the differential diagnosis of a clinically significant large fourth ventricle in a shunted child with PHH and CP. This includes conditions without pressure in the posterior fossa such as tissue loss due to cerebellar atrophy, or pathologies causing a true increase in pressure of the fourth ventricle (isolated fourth ventricle, cystic lesions and neoplasms of the fourth ventricle). Neurologically compromised children pose additional challenges in reaching a definitive diagnosis and hence require a careful regular assessment of their clinical status with additional well-timed imaging with appropriate protocols to allow appropriate treatment when indicated and to avoid morbidity due to delayed diagnosis. We present a rare coexistence of a dermoid tumor within the fourth ventricle in a CP child with PHH and express the dilemmas associated with its management.

Repeated tapping of ventricular reservoir in preterm infants with post-hemorrhagic ventricular dilatation does not increase the risk of reservoir infection

OBJECTIVE

Controlled removal of cerebrospinal fluid (CSF) by serial tapping of ventricular reservoir, such as the McComb reservoir, is an effective way to decompress the ventricular system in preterm infants with rapidly progressing post-hemorrhagic ventricular dilatation (PHVD) while awaiting optimal conditions for permanent CSF drainage through a ventriculo-peritoneal shunt. However, the data regarding the risk of infection from repeated invasive tapping of a ventricular reservoir over a prolonged period are scarce. The aim of this study is to determine the incidence of ventricular reservoir infection from repeated tapping and to evaluate how often reservoir infection accompanies blood culture-proven sepsis in preterm infants with PHVD.

STUDY DESIGN

We reviewed the medical records of all infants with PHVD receiving serial reservoir tap at the University of Michigan from January 2000 through June 2007. Serial reservoir taps were carried out by the neonatology team using aseptic technique. Surveillance CSF cultures were sent on a weekly basis as per unit practice or when clinical sepsis was suspected. Reservoir-tapping-related infection was present if a reservoir became infected during serial tapping 7 days or more after surgical placement of the reservoir.

RESULT

During the study period, ventricular reservoirs were placed in 35 infants for management of hydrocephalus. Six infants (17%) received ventricular reservoirs secondary to post-meningitic hydrocephalus or congenital brain malformations and were excluded. In the remaining 29 infants (birth weight: 1070+/-639 g (range 525 to 3204); gestational age: 26.9+/-4.1 weeks (range 23 to 40)) with PHVD, serial tapping of the ventricular reservoir was performed on 681 occasions (average number of taps per infant: 24 (range 2 to 82)). There were no cases of CSF culture-proven reservoir infection related to repeated taps. Thirteen of the 29 (45%) infants with PHVD developed blood culture-proven late onset sepsis with the following organisms: coagulase-negative Staphylococcus (9), Candida albicans (2), Escherichia coli (1), and Staphylococcus aureus (1), but all of the accompanying CSF cultures from the reservoir were negative.

CONCLUSION

Ventricular reservoir infection from serial taps neither occurred in this consecutive series of preterm infants with PHVD, nor did ventricular reservoir infection accompany blood culture-proven sepsis. Concern of reservoir infection from repeated tapping should not be a limiting factor against placement of reservoirs.

On the changing epidemiology of hydrocephalus

PURPOSE

The purpose of this study is to evaluate the changing epidemiology of paediatric hydrocephalus over the past three decades in a single institution.

METHODS

All children treated for newly diagnosed hydrocephalus during the 1985-1990 (group A) and the 2000-2005 periods (group B) were enrolled and classified according to the associated cause of hydrocephalus.

RESULTS

A significant 8.8% decrease of the incidence of hydrocephalus was noticed between the two time periods, resulting from the reduction of hydrocephalus associated to myelomeningocele, aqueduct stenosis (p = 0.04), CNS infection (p = 0.03), cranio-cerebral malformation and head injuries; post-haemorrhagic hydrocephalus remained stable, while the tumour-associated one increased (p < 0.0001). No consistent differences in terms of rate of adjunctive surgery (30.3% versus 23.9%) and number revision procedures (200 versus 104) were recorded.

CONCLUSIONS

The present study confirmed data from the literature about the declined incidence of paediatric hydrocephalus, which mainly results from the decrease of congenital malformations. In spite of the recent advances in neuroendoscopy and in the shunting valve design, the impact of hydrocephalus in the paediatric neurosurgical practice remains high.

Syringomyelia secondary to posthemorrhagic hydrocephalus in a preterm infant

Syringomyelia is often associated with hydrocephalus, especially in Chiari malformations, but it has never been described as a complication of posthemorrhagic hydrocephalus after preterm birth. We report on a premature infant who presented this exceptional association. He was born at 29 weeks of gestational age and suffered a grade 3 intraventricular hemorrhage. Progressive ventricular dilatation developed despite repeated lumbar punctures, and a ventricular reservoir had to be inserted for cerebrospinal fluid drainage. Two weeks later he presented a flaccid, areflexic paralysis of his left upper limb. Magnetic resonance imaging disclosed a remarkable tetraventricular hydrocephalus and a cervical hydrosyringomyelia expanding from the C(5) to T(1) segments. After shunt surgery, the cephalic perimeter stabilized, and the infant began to move his arm. On follow-up, a minimal paresis of the left hand persisted. This case highlights an unreported outcome of posthemorrhagic hydrocephalus. In this context, syringomyelia should be included in the differential diagnosis of any infant with who presents segmental signs of acute or progressive onset.

Cerebral hemodynamics and oxygenation after serial CSF drainage in infants with PHVD

The aim of our study was to assess consecutive changes in cerebral oxygenation and hemodynamics after serial cerebrospinal fluid (CSF) drainage from a subcutaneous ventricular catheter reservoir (SVCR) in infants with PHVD. Infants with PHVD were studied during CSF drainage from a SVCR on the day of SVCR placement, half a week and one week after SVCR placement. Changes in cHbD and CBV were assessed using near infrared spectrophotometry. Time averaged peak flow velocity (TAPFV), end diastolic flow velocity (EDFV), peak systolic flow velocity (PSFV) and pulsatility index (PI) were measured before (baseline) and after CSF drainage using Doppler ultrasound. Longitudinal data analysis was performed using linear mixed models. Seven patients (GA 26.7-40.4 weeks, BW 800-4575 g) were studied. CSF drainage resulted in a statistically significant increase in CBV during each measurement. The change in CBV was maximal on the day of SVCR placement. A significant increase in cHbD and EDFV, and decrease in PI was observed after CSF drainage only on the day of SVCR placement. Baseline values of all Doppler variables improved consecutively after serial CSF removal in the first week after SVCR placement. Frequent CSF drainage results in consecutive improvement of cerebral perfusion and oxygenation in infants with PHVD.

Variable interpretation of ultrasonograms may contribute to variation in the reported incidence of white matter damage between newborn intensive care units in New Zealand

BACKGROUND

The incidence of cerebral white matter damage reported to the Australian and New Zealand Neonatal Network (ANZNN) varies between neonatal intensive care units (NICUs).

HYPOTHESIS

Differences in the capture, storage, and interpretation of the cerebral ultrasound scans could account for some of this variation.

METHODS

A total of 255 infants of birth weight <1500 g and gestation <32 weeks born between 1997 and 2002 and drawn equally from each of the six NICUs in New Zealand were randomly selected from the ANZNN database. Half had early cerebral ultrasound scans previously reported to ANZNN as normal, and half had scans reported as abnormal. The original scans were copied, anonymised, and independently read by a panel of three experts using a standardised method of reviewing and reporting.

RESULTS

There was considerable variation between NICUs in methods of image capture, quality, and completeness of the scans. There was only moderate agreement between the reviewers' reports and the original reports to the ANZNN (kappa 0.45-0.51) and between the reviewers (kappa 0.54-0.64). The reviewers reported three to six times more white matter damage than had been reported to the ANZNN.

CONCLUSION

Some of the reported variation in white matter damage between NICUs may be due to differences in capture and interpretation of cerebral ultrasound scans.

Accumulation of Transforming Growth Factor-β2 and Nitrated Chondroitin Sulfate Proteoglycans in Cerebrospinal Fluid Correlates with Poor Neurologic Outcome in Preterm Hydrocephalus

BACKGROUND

Progressive post-hemorrhagic hydrocephalus in preterm infants strongly predicts abnormal neurologic development, and often accompanies cystic periventricular leukomalacia (cPVL). Transforming growth factor-beta1 (TGF-beta1), associated with hydrocephalus, can upregulate the chondroitin sulfate proteoglycan (CSPG) synthesis. To date, CSPG and their nitrated metabolites (NT-CSPG) have not been evaluated in hydrocephalus.

OBJECTIVES

We hypothesized that TGF-beta1, TGF-beta2, CSPG, and NT-CSPG would accumulate in cerebrospinal fluid (CSF) in preterm hydrocephalus, and their concentrations would correlate with poor long-term outcomes.

METHODS

TGF-beta1, TGF-beta2, CSPG, and NT-CSPG concentrations in CSF were measured prospectively by ELISA in 29 preterm newborns with (n=22) or without (n=34) progressive post-hemorrhagic hydrocephalus, and correlated with progressive neonatal hydrocephalus and neurologic outcome. Only concentrations from each patient's initial CSF sample were used for statistical analysis.

RESULTS

Compared to neonates without hydrocephalus, CSF [TGF-beta1], [TGF-beta2], [CSPG] and [NT-CSPG] were significantly greater by >3-, >35-, >8-, and >3-fold, respectively. Unlike CSF [TGF-beta2] and [CSPG], [TGF-beta1] correlated with CSF [total protein]. Only CSF [NT-CSPG] correlated with cPVL. Unlike [TGF-beta2] or [CSPG], [NT-CSPG] correlation with preterm progressive post-hemorrhagic hydrocephalus (PPHH) was explained entirely by the presence of cPVL among these patients. [TGF-beta2] was >20-fold greater in preterm survivors who required a ventriculoperitoneal shunt for PPHH (n=9), as compared to survivors who did not require a shunt (n=2), or those without hydrocephalus (n=12). [TGF-beta2] and [NT-CSPG] correlated inversely with Bayley Index Scores (15.0 months median adjusted age).

CONCLUSIONS

This is the first report that [TGF-beta2], [CSPG], and [NT-CSPG], measured well before term, accumulate abnormally in preterm progressive post-hemorrhagic hydrocephalus CSF, and correlate with adverse neurologic outcome.

Magnetic resonance and ultrasound brain imaging in preterm infants

Cranial ultrasonography has been used to identify brain injury in preterm neonates for more than two decades. More recently, magnetic resonance imaging has been used to evaluate brain development and pathology in these infants. In this review we describe how well findings from these two imaging modalities agree with histology findings and neuro-developmental outcome. In addition, we discuss studies comparing ultrasound and magnetic resonance imaging findings.

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.

Role of tissue-derived plasminogen activator (t-PA) in an excitotoxic mouse model of neonatal white matter lesions

White matter (WM) lesions in preterm newborns may lead to cerebral palsy. To study WM lesions in a mouse model, we used intrapallial stereotactic injections of ibotenic acid, an N-methyl-D-aspartate receptor agonist. Previous studies support a contribution of tissue-type plasminogen activator (t-PA) to the brain lesions seen in various adult excitotoxic models. Therefore, we studied both 5-day-old (P5) wild-type mice and t-PA knock-out (t-PA-/-) mice. The ibotenic acid doses required to induce WM cysts were lower in the wild-type mice (EC50 < 0.01 microg/animal) than in the t-PA-/- mice (EC50 = 2.5 microg/animal) (p < 0.01), indicating the existence of t-PA-dependent and t-PA-independent mechanisms. Dose-dependent prolonged cyst growth occurred in the wild-type mice only. Early microglial activation and astrogliosis were similar in the wild-type and t-PA-/- mice. In adult mice (P45), demyelination occurred at the injection site in both groups but the astroglial scar was denser in the wild-type than in the t-PA-/- mice. These data support involvement of t-PA at several stages of WM lesion formation. Inactivation of t-PA might confer protection by prolonged hemostasis. The role of t-PA in cyst expansion suggests a new approach to the development of neuroprotective strategies in infants with developing WM lesions.

Posthaemorrhagic ventricular dilatation: new mechanisms and new treatment

Post haemorrhagic ventricular dilatation is associated with a high rate of disability, multiple impairments and adverse effects of shunt surgery for hydrocephalus. Post haemorrhagic ventricular dilatation results initially from multiple small blood clots throughout the cerebrospinal fluid channels impeding circulation and re-absorption. Transforming growth factor beta is released into the cerebrospinal fluid and there is evidence that this cytokine stimulates the laying down of extracellular matrix proteins which produce permanent obstruction to the cerebrospinal fluid pathways. Prolonged raised pressure, pro-inflammatory cytokines and free radical damage from iron may contribute to periventricular white matter damage and subsequent disability. Interventions such as early lumbar punctures, diuretic drugs to reduce cerebrospinal fluid production and intraventricular fibrinolytic therapy have been tested and, not only fail to prevent shunt dependence, death or disability, but have significant adverse effects. Surgical interventions such as subcutaneous reservoir, external drain, choroid plexus coagulation and third ventriculostomy have not been subject to controlled trial. Ventriculoperitoneal shunt is not feasible in the early phase after intraventricular haemorrhage but, despite the problems with blockages and infections, remains the only option for infants with excessive head expansion over periods of weeks. We have piloted drainage, irrigation and fibrinolytic therapy as a way of removing blood early enough to stop the progressive deposition of matrix proteins, permanent hydrocephalus and shunt dependence.

Acquired aqueductal stenosis in preterm infants: an indication for neuroendoscopic third ventriculostomy

OBJECT

The object of this study is to demonstrate the delayed occurrence of aqueductal stenosis in preterm infants who have suffered from intraventricular hemorrhage (IVH) and to try to explain the mechanisms of this stenosis.

METHOD

From January 1996 to June 2002, 1,046 premature infants were admitted to our institution. Thirty-six neonates suffered from grade 3 or 4 intraventricular hemorrhage (Papile grading), of whom 16 died. Twenty patients survived and a ventriculoperitoneal shunt was inserted in 7 infants. Four patients underwent a neuroendoscopic third ventriculostomy. Follow-up was carried out, twice a month during the first 2 months and subsequently twice a year.

CONCLUSION

In 2 children NTV was an effective treatment for hydrocephalus with an average follow-up of 29 months. The specific pattern concerning these patients is the long delay before obstructive hydrocephalus and the visualization of de novo obstruction with MRI. The biological explanation must be investigated.

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.