Subacute hydrocephalus after experimental subarachnoid hemorrhage: its prevention by intrathecal fibrinolysis with recombinant tissue plasminogen activator

Posttraumatic hydrocephalus: Recent advances and new therapeutic strategies

Background

Hydrocephalus or ventriculomegaly is a condition brought on by an overabundance of cerebrospinal fluid (CSF) in the ventricular system. The major contributor to posttraumatic hydrocephalus (PTH) is traumatic brain injuries (TBIs), especially in individuals with occupations set in industrial settings. A variety of criteria have been employed for the diagnosis of PTH, including the combination of neurological symptoms like nerve deficits and headache, as well as an initial improvement followed by a worsened relapse of altered consciousness and neurological deterioration, which is detected by computed tomography-brain imaging that reveals gradual ventriculomegaly.

Aim

In this article, we discuss and summarize briefly the current understandings and advancements in the management of PTH.

Methods

The available literature for this review was searched on various bibliographic databases using an individually verified, prespecified approach. The level of evidence of the included studies was considered as per the Centre for Evidence-Based Medicine recommendations.

Results

The commonly practiced current treatment modality involves shunting CSF but is often associated with complications and recurrence. The lack of a definitive management strategy for PTH warrants the utilization of novel and innovative modalities such as stem cell transplantations and antioxidative stress therapies.

Conclusion

One of the worst complications of a TBI is PTH, which has a high morbidity and mortality rate. Even though there hasn't been a successful method in stopping PTH from happening, hemorrhage-derived blood, and its metabolic by-products, like iron, hemoglobin, free radicals, thrombin, and red blood cells, may be potential targets for PTH hindrance and management. Also, using stem cell transplantations in animal models and antioxidative stress therapies in future studies can lower PTH occurrence and improve its outcome. Moreover, the integration of clinical trials and theoretical knowledge should be encouraged in future research projects to establish effective and updated management guidelines for PTH.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Intraventricular urokinase to treat a blocked ventriculoperitoneal shunt in a glioblastoma patient with leptomeningeal spread

Leptomeningeal spread and hydrocephalus are increasingly recognized as late disease complications of glioblastoma with almost a quarter of patients requiring early cerebrospinal fluid shunting. The neurosurgeon is challenged with maintaining shunt patency when tumor disease progression is rapid and adjuvant oncologic therapy has yet to be initiated. We describe our experience in treating a young female with diffuse glioblastoma leptomeningeal spread and communicating hydrocephalus who had several episodes of shunt obstruction due to intraluminal tumor cell-fibrin deposits. Regular intraventricular instillations of urokinase fibrinolytic therapy not only re-established shunt patency but also contributed to the resolution of her hydrocephalus.

Tumeurs du cône médullaire et de la queue de cheval associées à l’hydrocéphalie chronique: à propos de 2 cas

L’hydrocéphalie chronique associée à une tumeur du cône médullaire et /ou de la queue de cheval est extrêmement rare. Nous présentons deux patients porteurs d’une tumeur médullaire révélée par la triade: démence, troubles de la marche et incontinence urinaire. L’imagerie par résonance magnétique (IRM) cérébrospinale objectivait une hydrocéphalie communicante et une tumeur intradurale siégeant au niveau du cône médullaire et de la queue de cheval. L’exérèse chirurgicale d’un schwannome bénin et d’un épendymome a permis la résolution de la symptomatologie clinique due à l’hydrocéphalie sans procéder à un shunt ventriculaire. Une dizaine de cas de démence et d’hydrocéphalie accompagnant une tumeur spinale sont rapportées. Une variété de mécanismes a été proposée pour expliquer cette association mais la physiopathologie exacte reste mal connue.

Acute hydrocephalus due to a primary malignant peripheral nerve sheath tumor of the cervicothoracic junction: A case report and review of the literature

BACKGROUND

The estimated incidence of malignant nerve sheath tumors is 0.001% per year, and only 2-3% of those tumors involve the spinal nerves. We present a rare case of acute hydrocephalus caused by primary malignant peripheral nerve sheath tumor of the cervicothoracic junction.

CASE DESCRIPTION

A 29-year-old previously healthy male patient, except for a history of two previous surgeries for ulnar nerve entrapment and progressive left upper extremity weakness, presented with acute onset somnolence. The CT and MRI revealed hydrocephalus and periventricular edema. The patient underwent ventriculoperitoneal shunt surgery. Postoperative MRI of the spine revealed a 6×3×3cm intra-extradural lesion at C7-T1 level and multiple metastases in other spinal segments. The patient underwent combined surgical excision and the tumor was diagnosed as a malignant peripheral nerve sheath tumor based on pathological and immunohistological findings. Radiation therapy and chemotherapy were initiated.

CONCLUSION

Primary malignant peripheral nerve sheath tumor of the spine is a very aggressive tumor with a very high recurrence rate, significant potential for metastasis and very poor overall prognosis. They may present with features of more frequent diseases, such as peripheral neuropathies and may be overlooked as in our case. Thus, suspected cases should undergo a more detailed examination.

Post-hemorrhagic hydrocephalus: Recent advances and new therapeutic insights

Post-hemorrhagic hydrocephalus (PHH), also referred to as progressive ventricular dilatation, is caused by disturbances in cerebrospinal fluid (CSF) flow or absorption following hemorrhage in the brain. As one of the most serious complications of neonatal/adult intraventricular hemorrhage (IVH), subarachnoid hemorrhage (SAH), and traumatic brain injury (TBI), PHH is associated with increased morbidity and disability of these events. Common sequelae of PHH include neurocognitive impairment, motor dysfunction, and growth impairment. Non-surgical measures to reduce increased intracranial pressure (ICP) in PHH have shown little success and most patients will ultimately require surgical management, such as external ventricular drainage and shunting which mostly by inserting a CSF drainage shunt. Unfortunately, shunt complications are common and the optimum time for intervention is unclear. To date, there remains no comprehensive strategy for PHH management and it becomes imperative that to explore new therapeutic targets and methods for PHH. Over past decades, increasing evidence have indicated that hemorrhage-derived blood and subsequent metabolic products may play a key role in the development of IVH-, SAH- and TBI-associated PHH. Several intervention strategies have recently been evaluated and cross-referenced. In this review, we summarized and discussed the common aspects of hydrocephalus following IVH, SAH and TBI, relevant experimental animal models, clinical translation of in vivo experiments, and potential preventive and therapeutic targets for PHH.

Subependymal Giant Cell Astrocytoma: Associated Hyperproteinorrhachia Causing Shunt Failures and Nonobstructive Hydrocephalus - Report of Successful Treatment with Long-term Follow-up

Subependymal giant cell astrocytomas (SEGAs) are histologically benign tumors most frequently associated with tuberous sclerosis complex (TSC). Despite their benign histopathological appearance, they may cause unfavorable outcomes due to their intraventricular location. Rarely, SEGA may be associated with hyperproteinorrhachia (high levels of proteins in the cerebrospinal fluid [CSF]), which causes malresorptive, communicating hydrocephalus; certainly, this scenario makes shunt obstruction likely in this patient population. In this report, we illustrate the case of hyperproteinorrhachia in an SEGA patient with known TSC, who presented repeatedly with shunt failure from proteinaceous shunt obstruction. Subsequent surgical resection of the main intraventricular lesion resulted in a dramatic drop in the CSF protein levels and has since prevented further shunt failures. Different treatment concepts and possible pathophysiology are discussed and the pertinent literature is reviewed.

Nonsurgical therapy for hydrocephalus: a comprehensive and critical review

Pharmacological interventions have been tested experimentally and clinically to prevent hydrocephalus and avoid the need for shunting beginning in the 1950s. Clinical trials of varied quality have not demonstrated lasting and convincing protective effects through manipulation of cerebrospinal fluid production, diuresis, blood clot fibrinolysis, or manipulation of fibrosis in the subarachnoid compartment, although there remains some promise in the latter areas. Acetazolamide bolus seems to be useful for predicting shunt response in adults with hydrocephalus. Neuroprotection in the situation of established hydrocephalus has been tested experimentally beginning more recently. Therapies designed to modify blood flow or pulsation, reduce inflammation, reduce oxidative damage, or protect neurons are so far of limited success; more experimental work is needed in these areas. As has been recommended for preclinical studies in stroke and brain trauma, stringent conditions should be met for preclinical studies in hydrocephalus.

New concepts in the pathogenesis of hydrocephalus

Hydrocephalus is a central nervous system disorder characterized by excessive accumulation of cerebrospinal fluid (CSF) in the ventricles of the brain. Cognitive and physical handicap can occur as a result of hydrocephalus. The disorder can present at any age as a result of a wide variety of different diseases. The pathophysiology of hydrocephalus is unclear. While circulation theory is widely accepted as a hypothesis for the development of hydrocephalus, there is a lack of adequate proof in clinical situations and in experimental settings. However, there is growing evidence that osmotic gradients are responsible for the water content of the ventricles of the brain, similar to their presence in other water permeable organs in the body. Therefore, brain disorders that results in excess macromolecules in the ventricular CSF will change the osmotic gradient and result in hydrocephalus. This review encompasses several key findings that have been noted to be important in the genesis of hydrocephalus, including but not limited to the drainage of CSF through the olfactory pathways and cervical lymphatics, the paravascular pathways and the role of venous system. We propose that as osmotic gradients play an important role in the water transport into the ventricles, the transport of osmotically active macromolecules play a critical role in the genesis of hydrocephalus. Therefore, we can view hydrocephalus as a disorder of macromolecular clearance, rather than circulation. Current evidence points to a paravascular and/or lymphatic clearance of these macromolecules out of the ventricles and the brain into the venous system. There is substantial evidence to support this theory, and further studies may help solidify the merit of this hypothesis.

Intracisternal administration of tissue plasminogen activator improves cerebrospinal fluid flow and cortical perfusion after subarachnoid hemorrhage in mice

Early brain injury (EBI) during the first 72 h after subarachnoid hemorrhage (SAH) is an important determinant of clinical outcome. A hallmark of EBI, global cerebral ischemia, occurs within seconds of SAH and is thought to be related to increased intracranial pressure (ICP). We tested the hypothesis that ICP elevation and cortical hypoperfusion are the result of physical blockade of cerebrospinal fluid (CSF) flow pathways by cisternal microthrombi. In mice subjected to SAH, we measured cortical blood volume (CBV) using optical imaging, ICP using pressure transducers, and patency of CSF flow pathways using intracisternally injected tracer dye. We then assessed the effects of intracisternal injection of recombinant tissue plasminogen activator (tPA). ICP rose immediately after SAH and remained elevated for 24 h. This was accompanied by a decrease in CBV and impaired dye movement. Intracisternal administration of tPA immediately after SAH lowered ICP, increased CBV, and partially restored CSF flow at 24 h after SAH. Lowering ICP without tPA, by draining CSF, improved CBV at 1 h, but not 24 h after SAH. These findings suggest that blockade of CSF flow by microthrombi contributes to the early decline in cortical perfusion in an ICP-dependent and ICP-independent manner and that intracisternal tPA may reduce EBI and improve outcome after SAH.

Hydrocephalus associated with spinal intramedullary pilocytic astrocytoma

Hydrocephalus secondary to intraspinal tumors is a well-known but rare condition. We report a case of holocord intramedullary pilocytic astrocytoma associated with hydrocephalus in a 29-year-old male patient. He underwent ventriculoperitoneal shunt followed by subtotal resection of the tumor.

Prognostic Value of Intraventricular Bleeding in Spontaneous Intraparenchymal Cerebral Hemorrhage of Small Volume: A Prospective Cohort Study

BACKGROUND:

The literature is controversial on whether intraventricular bleeding has a negative impact on the prognosis of spontaneous intracerebral hemorrhage. Nevertheless, an association between intraventricular bleeding and spontaneous intracerebral hemorrhage volumes has been consistently reported.

OBJECTIVE:

To evaluate the prognostic value of intraventricular bleeding in deep intraparenchymal hypertensive spontaneous hemorrhage with a bleeding volume <30 cm3.

METHODS:

Of the 320 patients initially evaluated, 33 met the inclusion criteria and were enrolled in this prospective study. The volume of intraparenchymal hemorrhage was calculated by brain computed tomography (CT) image analysis, and the volume of intraventricular bleeding was calculated by the LeRoux scale. Clinical data, including neurological complications, were collected daily during hospitalization. Neurological outcome was evaluated 30 days after the event by using the Glasgow outcome scale. Patients were assigned to 1 of 3 groups according to intraventricular bleeding: Control, no intraventricular bleeding; LR 1, intraventricular bleeding with LeRoux scale scores of 1 to 8; or LR 2, intraventricular bleeding with LeRoux scale scores >8.

RESULTS:

There were no significant differences among groups concerning age, mean blood pressure, and time from onset to brain CT scan. Patients with greater intraventricular bleeding presented lower initial Glasgow coma scale scores, increased ventricular index and width of temporal horns, increased number of clinical and neurological complications, and longer hospitalization. Furthermore, their relative risk for unfavorable clinical outcome was 1.9 (95% confidence interval 1.25-2.49).

CONCLUSION:

Intraventricular bleeding with a LeRoux scale score >8 appears to have a negative effect on deep spontaneous intraparenchymal cerebral hemorrhage of small volume.

Hydrocephalus and spinal cord tumors: a review

INTRODUCTION

Hydrocephalus secondary to intraspinal tumors is a well-known but rare condition since about 1% of patients with spinal cord tumors have various degrees of hydrocephalus at initial presentation.

DISCUSSION

The mechanism of development of intracranial hypertension and hydrocephalus in patients with spinal cord tumor is not exactly known. The problematic aspects of this condition, with regard to clinical presentation and pathophysiology, are discussed and the relevant literature is reviewed. This uncommon association should always be kept in mind in the differential diagnosis of hydrocephalus of unknown etiology for three main reasons: the possibility of neurological deterioration if the patient is shunted prior tumor removal, the possibility to treat the hydrocephalus without shunting by simply removing the tumor, and the possible role of hydrocephalus as an early sign of intracranial metastasis in patients previously operated upon for removal of intramedullary gliomas. Due to the very slow evolution of the disease, a careful and close clinical and neuroradiological follow-up are essential for many years afterward. The presence of intracranial hypertension in a patient previously operated for a spinal tumor should be considered and investigated as an early sign of neoplastic intracranial seeding.

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.

Intraventricular infusion of hyperosmolar dextran induces hydrocephalus: a novel animal model of hydrocephalus

BACKGROUND

Popular circulation theory of hydrocephalus assumes that the brain is impermeable to cerebrospinal fluid (CSF), and is therefore incapable of absorbing the CSF accumulating within the ventricles. However, the brain parenchyma is permeable to water due to the presence of specific ion channels as well as aquaporin channels. Thus, the movement of water into and out of the ventricles may be determined by the osmotic load of the CSF. If osmotic load determines the aqueous content of CSF in this manner, it is reasonable to hypothesize that hydrocephalus may be precipitated by pathologies and/or insults that produce sustained elevations of osmotic content within the ventricles.

METHODS

We investigated this hypothesis by manipulating the osmotic content of CSF and assaying the development of hydrocephalus in the rat brain. This was achieved by continuously infusing artificial CSF (negative control; group I), fibroblast growth factor (FGF2) solution (positive control; group II) and hyperosmotic dextran solutions (10 KD and 40 KD as experimental solutions: groups III and IV) for 12 days at 0.5 muL/h. The osmolality of the fluid infused was 307, 664, 337 and 328 mOsm/L in Groups I, II, III and IV, respectively. Magnetic resonance imaging (MRI) was used to evaluate the ventricular volumes. Analysis of variance (ANOVA) with pairwise group comparisons was done to assess the differences in ventricular volumes among the four groups.

RESULTS

Group I had no hydrocephalus. Group II, group III and group IV animals exhibited significant enlargement of the ventricles (hydrocephalus) compared to group I. There was no statistically significant difference in the size of the ventricles between groups II, III and IV. None of the animals with hydrocephalus had obstruction of the aqueduct or other parts of CSF pathways on MRI.

CONCLUSION

Infusing hyperosmolar solutions of dextran, or FGF into the ventricles chronically, resulted in ventricular enlargement. These solutions increase the osmotic load in the ventricles. Water influx (through the choroid plexus CSF secretion and/or through the brain) into the ventricles to normalize this osmotic gradient results in hydrocephalus. We need to revise the popular theory of how fluid accumulates in the ventricles at least in some forms of hydrocephalus.

Cohort study of intraventricular thrombolysis with recombinant tissue plasminogen activator for aneurysmal intraventricular hemorrhage

OBJECTIVE

Thrombolytic agents have been administered through external ventricular drains to treat intraventricular hemorrhage, the goals being to accelerate clot clearance, prevent catheter obstruction, and help control intracranial pressure. We compared these variables in a group of aneurysm patients treated by one surgeon who routinely used intraventricular recombinant tissue plasminogen activator (rt-PA) for obstructive hematocephalus with those in a group of similar patients treated by other surgeons who did not.

METHODS

Patients included in this analysis were those with repaired cerebral aneurysms causing hemorrhage into at least three ventricles with ventriculomegaly requiring external ventricular drainage. The ventricular system was considered "opened" when all ventricles were patent and reduced in size on computed tomographic scans. Those treated with rt-PA received 4 mg/d through a ventricular drain until ventricular opening.

RESULTS

The mean number of days to ventricular opening was 3.9 (standard deviation [SD], 1.0) for the 21 patients treated with rt-PA and 7.1 (SD, 3.7) for the 9 who were not (P = 0.001), and the mean intracranial pressure (mm Hg) 24 hours after treatment with rt-PA was 10.4 (SD, 6.1) compared with 14.1 (SD, 5.9) during the same interval for the group that did not receive rt-PA (P = 0.13). Ventricular catheter replacement was required in 1 rt-PA patient (for a misplaced catheter, before rt-PA treatment) and 3 patients who did not receive rt-PA (all for catheter obstructions with blood clot) (P = 0.07), and ventriculoperitoneal shunts were placed in 4 rt-PA patients and 3 patients who did not receive rt-PA (P = 0.4).

CONCLUSION

Intraventricular thrombolysis with rt-PA seems to assist in the acute management of patients with large aneurysmal intraventricular hemorrhages, speeding clearance of aneurysmal intraventricular hemorrhage, normalizing intracranial pressure, and reducing ventricular catheter obstruction. A randomized trial is needed to confirm these findings, establish treatment safety, and determine whether treatment affects outcome.

Posthaemorrhagic ventricular dilatation

Posthaemorrhagic ventricular dilatation is the most serious direct complication of intraventricular haemorrhage after preterm birth. It results initially from multiple small blood clots throughout the cerebrospinal fluid channels impeding circulation and reabsorption. Management is difficult and new treatment approaches are needed.

Randomized, controlled trial of acetazolamide and furosemide in posthemorrhagic ventricular dilation in infancy: follow-up at 1 year

OBJECTIVE

Posthemorrhagic ventricular dilation (PHVD) is a complication of intraventricular hemorrhage in preterm infants and is associated with a high risk of long-term disability. Furosemide and acetazolamide are used widely in the treatment of PHVD in the hope of avoiding the need for placement of a ventriculoperitoneal shunt, but these drugs have not been evaluated in a controlled trial. This article reports a multicenter, randomized, controlled trial designed to test the hypothesis that these drugs would reduce the rate of shunt placement (or death) and increase survival to 1 year of age without disability.

METHODS

Between 1992 and 1996, 177 infants who were less than 3 months past term and had ventricular width >4 mm above the 97th centile following intraventricular hemorrhage were assigned randomly to either standard therapy or standard therapy plus drug therapy with acetazolamide (100 mg/kg/d) plus furosemide (1 mg/kg/d). Infants who were enrolled in the trial had a median gestational age of 28.6 weeks and were enrolled at a mean postnatal age of 3.6 weeks. Forty-four percent were reported to have a cerebral parenchymal lesion on ultrasound scan at randomization. The primary outcome measure of death or shunt placement (known in all but 1 infant) occurred in 56 of 88 infants who were allocated to drug plus standard therapy compared with 46 of 88 who were allocated to standard therapy. The risk ratio was 1.23 (95% confidence interval: 0.95-1.59). Neurodevelopmental outcome information at a corrected age of 1 year (known in all but 3 of 149 surviving infants) included disability or neuromotor impairment in 54 of 67 infants (81%) who were allocated to drug plus standard therapy and 52 of 69 infants (66%) who were allocated to standard therapy. Seventy-two of 85 infants (85%) who were allocated to drug therapy either died or were disabled or impaired at 1 year compared with 62 of 89 infants (70%) who were treated with standard therapy (risk ratio: 1.22; 95% confidence interval: 1.03-1.4376). The excess risk of these adverse outcomes was greater among infants who did not have a cerebral parenchymal lesion seen on ultrasound examination at trial entry.

CONCLUSIONS

These results suggest that the use of acetazolamide and furosemide in preterm infants with PHVD is ineffective in decreasing the rate of shunt placement and is associated with increased neurologic morbidity. This treatment therefore cannot be recommended.

Intraventricular haemorrhage and posthaemorrhagic hydrocephalus: pathogenesis, prevention and future interventions

Intraventricular haemorrhage (IVH) is still a major complication of preterm birth with serious disability resulting. The fragile blood vessels in the germinal matrix below the ventricular lining and the instability of blood flow to this highly vascular area are the main mechanisms behind IVH. There is good evidence that corticosteroid therapy before preterm delivery reduces mortality and IVH substantially with a trend towards a reduction in disability. There is good evidence that postnatal indomethacin reduces IVH but no evidence that mortality or disability is reduced. There is evidence that stabilizing cerebral blood flow with pancuronium in infants with respiratory distress reduces IVH in the minority of infants with marked fluctuations. There is limited evidence that postnatal vitamin E and ethamsylate reduce IVH but insufficient evidence of reduced mortality or disability. Hydrocephalus following IVH results initially from multiple small blood clots throughout the CSF channels impeding circulation and re-absorption. Transforming growth factor beta is released into the CSF and there is mounting evidence that this cytokine stimulates the laying down of extracellular matrix proteins such as laminin and fibronectin which produce permanent obstruction to the CSF pathways. Interventions such as early lumbar punctures, diuretic drugs to reduce CSF 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 and external drain have not been subject to controlled trial. Ventriculoperitoneal shunt is not feasible in the early phase after IVH but, despite the problems with blockages and infections, remains the only option for infants with excessive head expansion over periods of weeks. New treatment approaches aimed at preventing hydrocephalus are needed.

Transforming growth factor-beta1: a possible signal molecule for posthemorrhagic hydrocephalus?

Posthemorrhagic hydrocephalus remains a complication of preterm birth for which we lack a clear understanding and a curative therapy. Transforming growth factor beta (TGF-beta) is a cytokine that upregulates the production by fibroblasts of extracellular matrix proteins. We hypothesized that TGF-beta might be released into cerebrospinal fluid (CSF) after intraventricular hemorrhage and play a role in posthemorrhagic hydrocephalus. Total TGF-beta1 and TGF-beta2 were measured by immunoassay in CSF samples from 12 normal preterm infants, nine preterm infants with transient posthemorrhagic ventricular dilation, and 10 infants who subsequently developed permanent hydrocephalus. Five infants received intraventricular tissue plasminogen activator, and two infants were treated by drainage irrigation and fibrinolytic therapy. Median TGF-beta1 in normal CSF was 0.495 ng/mL. In infants with transient posthemorrhagic ventricular dilation, median initial CSF TGF-beta1 was 2.1 ng/mL. Infants who subsequently had permanent hydrocephalus had median initial CSF TGF-beta1, 9.7 ng/mL (differences between groups p < 0.01). Intraventricular recombinant tissue plasminogen activator was followed by a rise in CSF TGF-beta1 (p = 0.0007). Drainage irrigation and fibrinolytic therapy was followed by a fall in CSF TGF-beta1. TGF-beta2 was detected in CSF and showed similar trends, but the CSF concentration of TGF-beta1 was more than 20 times higher. These findings support the hypothesis that TGF-beta1 is released into CSF after intraventricular hemorrhage and may play an important part in hydrocephalus. The results help to explain the failure of intraventricular fibrinolytic therapy.

Traumatic intraventricular hemorrhage treated with intraventricular recombinant-tissue plasminogen activator: technical case report

OBJECTIVE AND IMPORTANCE

Traumatic intraventricular hemorrhage (IVH) can result in association with acute obstructive hydrocephalus, repetitive malfunction of external ventricular drains (EVDs), and uncontrollable increased intracranial pressure. We report a case showing the safe and effective use of intraventricular recombinant-tissue plasminogen activator in a child with severe brain injury and acute hydrocephalus from IVH.

CLINICAL PRESENTATION

A 15-year-old male patient presented to us after a motor vehicle accident with bilateral extensor posturing, intracerebral and IVH, and acute obstructive hydrocephalus.

INTERVENTION

A right EVD was placed and functioned only transiently. A left EVD was placed and functioned only transiently. Because of the inability to maintain ventricular drainage, rising intracranial pressure, and worsening clinical status, 5 mg of recombinant-tissue plasminogen activator was injected through each EVD. Excellent EVD function was obtained quickly, with control of intracranial pressure and improvement in clinical status and without hemorrhagic complication.

CONCLUSION

With obstructive hydrocephalus secondary to acute traumatic IVH that cannot be controlled with EVD because of recurrent obstruction from intraventricular blood, intraventricular recombinant-tissue plasminogen activator can be effective and safe, despite preexisting multiple hemorrhagic intracranial injuries.

CNS fibrinolysis: a review of the literature with a pediatric emphasis

In vitro studies of cerebrospinal fluid indicate that normal cerebrospinal fluid contains very low levels of fibrinolytic enzymes but that fibrinolytic activity is higher in pathologic compared with normal conditions and in older compared with younger patients. Because of the low endogenous fibrinolytic activity of the central nervous system, intraventricular fibrinolytic therapy has been studied in adult and pediatric patients for the treatment of intraventricular hemorrhage/posthemorrhagic hydrocephalus and subarachnoid hemorrhage with secondary cerebral vasospasm. A review of the literature about endogenous and exogenous fibrinolysis studies of animals, adult humans, and pediatric humans reveals a record of predominant safety and efficacy. Although its use in the adult population for the treatment of subarachnoid hemorrhage with secondary vasospasm has become an accepted therapy in some centers, its use in the pediatric population is less common. It is no longer considered in the treatment of meningitis, but its role in the treatment of intraventricular hemorrhage/posthemorrhagic hydrocephalus is still being investigated.

Hydrocephalus

Hydrocephalus may be an acquired or congenital condition. Clinical signs often reflect the level of brain involvement. In young dogs, the presence of a dome-shaped head and/or persistent fontanel are suggestive of hydrocephalus. Ventriculoperitoneal shunting is often used for definitive treatment of hydrocephalus.

Phase I study of intraventricular recombinant tissue plasminogen activator for treatment of posthaemorrhagic hydrocephalus

AIM

Phase I study to evaluate intraventricular fibrinolytic treatment with recombinant tissue plasminogen activator (tPA) as a method of clearing blood from the cerebrospinal fluid, and thus preventing permanent hydrocephalus.

METHODS

Twenty two preterm infants, aged 7 to 26 days, with progressive posthaemorrhagic ventricular dilatation (ventricular width > 4 mm over 97th centile) received one to five intraventricular bolus injections of 1.0 mg or 0.5 mg tPA at intervals of one to seven days.

RESULTS

The mean cerebrospinal fluid concentration of tPA 24 hours after 1 mg was 1860 micrograms/ml. The half life of tPA in cerebrospinal fluid was about 24 hours. Twenty one (95%) infants survived, 12 (55%) without shunt surgery. One infant had secondary intraventricular haemorrhage.

CONCLUSION

Intraventricular tPA resulted in survival without a shunt for most of the infants, but with some risk. Failure may have been due to plasminogen deficiency, an inhibitor, or late intervention.

Endogenous tissue plasminogen activator in neonatal cerebrospinal fluid

Tissue type plasminogen activator (tPA) plays a role in differentiation of neurones and activity-dependent structural changes in neurones. We hypothesised that tPA would also be present in CSF during fibrinolysis after intraventricular haemorrhage. We measured tPA antigen in CSF from 13 normal newborn infants and 14 infants with post-haemorrhagic ventricular dilatation (PHVD). tPA was undetectable or at the limit of detection (1 microgram/l) in normal CSF. The CSF tPA concentration ranged from 1.3 to 3.5 micrograms/l in the infants with PHVD. Serial tapping in one infant showed persistence of tPA in the CSF from 3 to 8 weeks of age. We conclude that endogenous tPA may be part of the physiological response to intraventricular haemorrhage or may be present as a result of passive diffusion into the CSF.

Hydrocephalus associated with intramedullary low-grade glioma. Illustrative cases and review of the literature

Over the past 15 years, eight children affected by intramedullary low-grade gliomas associated with hydrocephalus were treated at l'Hôpital des Enfants Malades. In all cases the diagnosis of hydrocephalus was made prior to that of the spinal tumor. Neuroradiological examination of all patients revealed contrast enhancement of the intracranial subarachnoid spaces. In six cases this was progressive, suggesting subarachnoid spread of the tumor, which was confirmed in two cases by histological examination. The authors analyzed 38 cases of intramedullary low-grade glioma associated with hydrocephalus that were reported in the literature. Fifteen of the cases had intracranial leptomeningeal seeding. Several hypotheses have been proposed to explain this unusual association, such as 1) increase in cerebrospinal fluid (CSF) viscosity because of elevated fluid protein content; 2) obliteration of the cisterna magna due to a rostral extension of the tumor; and 3) blockage of the spinal subarachnoid pathways of CSF resorption. Two other theories seem of particular interest. Bamford and Labadie suggested that the abnormal presence of fibrinogen in the CSF and its transformation into fibrin at the level of the basal cisterns and Pacchioni's granulation may alter CSF hydrodynamics. This mechanism alone is sufficient to induce hydrocephalus of the communicating type. In addition, as suggested by Maurice-Williams and Lucey, the resulting leptomeningeal fibrosis might predispose secondary implantation of neoplastic elements in the subarachnoid spaces of the intracranial compartment.

"Head-shaking syndrome" neurological deterioration during continuous head-shaking as an adjunct to cisternal irrigation for clot removal in patients with acute subarachnoid haemorrhage

To prevent cerebral vasospasm after aneurysmal subarachnoid haemorrhage, cisternal irrigation has been reported to be more effective when combined with continuous head-shaking (head-shaking method). The present study was conducted to evaluate the safety and preventative effect for vasospasm in patients treated with the head-shaking method. Six of 17 patients managed postoperatively by the original head-shaking procedure developed neurological deterioration related to the method: two had intracranial haematoma (one with acute interhemispheric subdural haematoma, and the other with cerebellar haemorrhage), two had acute brain swelling, and two failed to show abnormal findings on computed tomography. These pathological processes may be suitably referred to as "head-shaking syndrome". Delayed ischaemic neurological deficits associated with low-density lesions on computed tomography were demonstrated in five patients (29%). From these observations, the head-shaking method may not be as safe as described in the original articles, and is critically evaluated in terms of its preventative effect for cerebral vasospasm.

Localization of tissue plasminogen activator mRNA in adult rat brain

The distribution of tissue plasminogen activator (tPA) messenger RNA in rat brain was studied using in situ hybridization with 35S UTP-labeled RNA probes derived from a full-length tPA cDNA. Sense strand controls produced low, even backgrounds, with small elevations in the hippocampus. Full-length antisense probes produced strong signals over cerebral ventricular ependyma (including ependyma of the subcommissural organ), meninges, blood vessels, and Purkinje cell layer of the cerebellum, as well as strong signals over scattered cells throughout the brain. Some of these scattered labeled cells were large with lightly stained nuclei, while others were small with darkly stained nuclei. The large labeled cells, which were probably neurons, constituted 6% and 8% of cells in the brain stem and neocortex, respectively, and 100% of Purkinje cells. The small cells, which were present in all areas of the brain, constituted 3-11% of cells in individual brain areas.

Treatment of intraventricular hemorrhage with tissue plasminogen activator

The patients with intraventricular hemorrhage (IVH) were treated with recombinant tissue plasminogen activator (rt-PA) injected directly into the lateral ventricles, followed by ventricular drainage. All had a decreased level of consciousness before treatment (Glasgow Coma Scale score 10 +/- 3.4). A total dose between 2 and 12 mg of rt-PA (6.4 +/- 3.3) was administered. For eight patients with aneurysmal IVH, treatment with rt-PA began with two patients the same day as the aneurysm clipping, and the day after with six patients. For a patient with an excision of a ruptured arteriovenous malformation and a patient with IVH resulting from a lateral ventricular catheterization during posterior fossa tumor surgery, treatment with rt-PA started 24 hours after surgery. After an injection of rt-PA, the ventricular drain was closed for 1 hour, followed by alternate-hourly drainage and intracranial pressure (ICP) monitoring. Five patients received a second injection of rt-PA on the second postoperative day, and one patient received a third dose on the third day. Among the eight patients given rt-PA the day after surgery, the volume of external cerebrospinal fluid (CSF) drainage for 24 +/- 8 hours before treatment was 61 +/- 57 ml, and the mean ICP was 22 +/- 5 mm Hg during this same time. Younger age and poorer neurological condition correlated with higher ICP before treatment.(ABSTRACT TRUNCATED AT 250 WORDS)