Mechanism Of Hydrocephalus Research Articles

Impact of thermodynamical rotational flow of cerebrospinal fluid in the presence of elasticity

ObjectiveTo explore the experimental justification of cerebrospinal fluid (CSF) amplitude and elastic fluctuations of ventricles, we extend our previous computational study to models with rotational flow and suitable boundary conditions. In the present study, we include an elastic effect due to the interaction with the thermal solutal model which accounts for CSF motion which flows rotationally due to hydrocephalus flows within the spinal canal.MethodsUsing an analytical pertubation method, we have attempted a new model to justify CSF flow movement using the influences of wall temperature difference.ResultsThis paper presents results from a computational study of the biomechanics of hydrocephalus, with special emphasis on a reassessment of the parenchymal elastic module. CSF amplitude in hydrocephalus patients is 2.7 times greater than that of normal subjects.ConclusionsThis finding suggests a non-linear mechanical system to present the hydrocephalic condition using a numerical model. The results can be useful to relieve the complexities in the mechanism of hydrocephalus and can shed light to support clinically for a convincing simulation.

К вопросу дифференциальной диагностики, классификации и дифференцированного лечения гидроцефалии и гидроцефальных синдромов у детей

Целью исследования было определение соотношения двух основных механизмов гидроцефалии и гидроцефальных синдромов — внутричерепной гипертензии и церебральной атрофии (гипотрофии) в структуре различных болезненных состояний у детей. Методом комплексного динамического определения структурно-органического внутричерепного дефекта у детей проведена дифференциальная диагностика двух основных патогенетических типов гидроцефалии и гидроцефальных синдромов у 483 детей, пролеченных в отделении для детей с поражением центральной нервной системы и психики в 2011–2014 годах. В результате исследования установлено значительное преобладание церебральной гипотрофии. Ликворная гипертензия была достоверной причиной расширения ликворных пространств только в 5,1 % случаев у больных с детским церебральным параличом в 19 % случаев в группе детей с последствиями пре-, перинатальной патологии нервной системы.Обсуждение результатов исследования позволило определить пути совершенствования методов диагностики и классификации гидроцефалии и гидроцефальных синдромов для проведения их адекватной дифференцированной терапии.Выводы. Учитывая вторичный характер расширения ликворных пространств при гипотрофии мозга предложено использовать термин «гипотрофически-гидроцефальный синдром» в структуре диагноза первичного заболевания, вызвавшего гипотрофию головного мозга.

Unruptured brain arteriovenous malformations and hydrocephalus: Case series and review of the literature

ObjectiveHydrocephalus is an uncommon presentation of unruptured brain arteriovenous malformations (AVMs). The goal of this case series and literature review is to present possible pathological mechanisms, management strategies and outcomes in patients with hydrocephalus due to unruptured AVMs. MethodsThree consecutive patients with hydrocephalus caused by unruptured AVMs as well as all cases previously reported in the literature were retrospectively reviewed to determine clinical symptoms, AVM location, nidus size, venous drainage, mechanism of hydrocephalus, level/cause of obstruction, and degree of hydrocephalus. Management of hydrocephalus, AVM treatment, and follow-up length were evaluated. ResultsOf 350 patients unruptured AVMs, 3 presented with hydrocephalus (0.8%). In the literature review we found an additional 22 patients for a total of 25 cases. Eighteen patients had mechanical obstruction by the draining vein or the AVM nidus, usually at the level of the aqueduct (52%). Impaired cerebrospinal fluid resorption secondary to venous congestion led to hydrocephalus in 7 patients. Ten patients were treated for both the AVM and hydrocephalus, 13 patients underwent treatment of either hydrocephalus, or the AVM alone. Treatment of hydrocephalus, with or without associated treatment of the brain AVM, resulted in improvement of symptoms in 92% of patients. No rupture of the AVM was reported at follow-up. ConclusionsThe most common cause of hydrocephalus in unruptured brain AVMs is mechanical obstruction by the draining vein if it is located in a strategic position. Treatment of hydrocephalus alone or with associated treatment of the AVM is safe and effective.

Management of hydrocephalus associated with autoimmune diseases: a series of 19 cases

Objectives: To analyze the diagnosis and treatment of hydrocephalus associated with autoimmune diseases and to explore the possible mechanism of hydrocephalus in these patients.Methods: A retrospective case series study was conducted at Peking Union Medical College Hospital, Beijing, China. Files were retrieved from the hospital archives by screening records from Jan 1990 to Jan 2016. Medical records were screened for data regarding (1) the number of patients diagnosed with hydrocephalus associated with autoimmune diseases, (2) the clinical manifestation of hydrocephalus associated with autoimmune disease, and (3) the outcomes of these patients treated with medication or ventriculoperitoneal shunt (VPS).Results: A total of 19 of 19,643 hospitalized autoimmune diseases patients were found to have hydrocephalus. Seven of the 19 patients had systemic lupus erythematosus (SLE), 3 patients had Sjögren’s syndrome, 2 patients had rheumatoid arthritis (RA), 1 patient had connective tissue disease, 1 patient had juvenile idiopathic arthritis (JIA), 1 patient had Guillain-Barre syndrome (GBS), 1 patient had systemic sclerosis, 1 patient had Crohn’s disease, 1 patient had relapsing polychondritis (RPC), and 1 patient had autoinflammatory disease (AID). Of the 19 patients, 13 received medication treatment, and the most commonly used drugs were corticosteroids and mannitol. A total of 6 patients received both medication therapy and VPS treatment with a programable valve. After average follow-up lengths of 11 months for patients who received VPS and 8.2 for patients who received medical treatment, the clinical symptoms of patients treated by VPS or medication were improved (83% (5/6) vs. 15.4% (2/13), respectively), patients were in stable condition (17% (1/6) vs. 30.8% (4/13), respectively), and mortality decreased (0% vs. 53.8% (7/13), respectively).Conclusions: VPS along with corticosteroids and immunosuppressants represents an effective treatment approach for patients who suffer from hydrocephalus associated with autoimmune diseases.

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...

Abstract W MP96: The Role of Thrombin in Hydrocephalus after Intraventricular Hemorrhage

Background: Hydrocephalus after intraventricular hemorrhage (IVH) is a common and major complication that causes clinical deterioration and affects recovery. The mechanisms of hydrocephalus are still not clear. Previous studies demonstrated that thrombin is an important factor in brain injury after intracerebral hemorrhage. This study investigated the effect of thrombin on hydrocephalus development in a rat IVH model. Methods: There were three parts in this study. First, male Sprague-Dawley rats had an injection of 200μl saline, autologous blood or heparinized blood into the right lateral ventricle and had MRI scanning to determine lateral ventricle size at different times up to 4 weeks. Second, rats had an injection of 50μl saline or 3U thrombin into the right lateral ventricle. Third, rats had an injection of thrombin (3U) with a protease-activated receptor-1 (PAR-1) antagonist, SCH79797 (0.15 nmol), or vehicle into the right lateral ventricle. Lateral ventricle volumes were measured by MRI and the brains were used for immunohistochemistry and Western blot analysis at 24 hours. Results: Intraventricular injection of autologous blood induced hydrocephalus from day-1 to -28. Co-injection of heparin with blood resulted in less hydrocephalus at all time points compared with blood injection alone (p<0.05). Intraventricular injection of thrombin, but not saline induced significant hydrocephalus, ventricular wall damage, blood-brain barrier disruption, and PAR-1 upregulation in the periventricular area. Thrombin-induced hydrocephalus was reduced by co-injection of the PAR-1 antagonist SCH79797 (p<0.05). Conclusions: Thrombin contributes to hydrocephalus development after intraventricular hemorrhage and thrombin-induced hydrocephalus is through activation of PAR-1.

Disruption of Wave-associated Rac GTPase-activating Protein (Wrp) Leads to Abnormal Adult Neural Progenitor Migration Associated with Hydrocephalus

Hydrocephalus is the most common developmental disability and leading cause of brain surgery for children. Current treatments are limited to surgical intervention, as the factors that contribute to the initiation of hydrocephalus are poorly understood. Here, we describe the development of obstructive hydrocephalus in mice that are null for Wrp (Srgap3). Wrp is highly expressed in the ventricular stem cell niche, and it is a gene required for cytoskeletal organization and is associated with syndromic and psychiatric disorders in humans. During the postnatal period of progenitor cell expansion and ventricular wall remodeling, loss of Wrp results in the abnormal migration of lineage-tagged cells from the ventricular region into the corpus callosum. Within this region, mutant progenitors appear to give rise to abnormal astroglial cells and induce periventricular lesions and hemorrhage that leads to cerebral aqueductal occlusion. These results indicate that periventricular abnormalities arising from abnormal migration from the ventricular niche can be an initiating cause of noncommunicating hydrocephalus.

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.

Effect of non-linear permeability in a spherically symmetric model of hydrocephalus

We examine a spherically symmetric model of the brain and apply non-linear permeability in a small strain poroelastic framework. Numerical solutions to the model show that non-linear effects tend to improve predictions of ventricle wall displacement and pressure increase in acute hydrocephalus in comparison with a constant permeability model. Our model is used to study different mechanisms for hydrocephalus: complete blockage of the aqueduct and normal pressure hydrocephalus (NPH), as well as offering observations on mechanical effects in idiopathic intracranial hypertension. In each situation it is possible to apply different parameter conditions to quantify mechanical effects that correspond to some observed symptoms. The results support and quantify ideas from Levine (2000, Ventricle size in pseudotumor cerebri and the theory of impaired CSF absorption. J. Neurol. Sci., 177, 85-94) on a poroelastic mechanism for some features of NPH and idiopathic intracranial hypertension.

Non-obstructive hydrocephalus associated with intracranial schwannomas: hyperproteinorrhachia as an etiopathological factor?

This series illustrates the association of communicating hydrocephalus with intracranial non-obstructive schwannomas. This association has commonly been observed, however it has only been reported once previously. Moreover, in all the patients we present, hyperproteinorrhachia was a common denominator. This finding may therefore be the underlying mechanism for hydrocephalus. Seven patients presenting with intracranial schwannomas along with non-obstructive hydrocephalus and hyperproteinorrhachia are reported. Six had a vestibular schwannoma and presented with a unilateral deafness and various degrees of gait disturbance, urinary incontinence and neuropsychological impairment. Due to their advanced ages, these patients underwent a ventriculo-peritoneal shunt, and their symptoms related to hydrocephalus resolved. One patient that suffered from hemifacial dysesthesia and memory deficits presented with a non-obstructive trigeminal schwannoma. In this case the tumour was removed and the hydrocephalus was consequently reversed, and the CSF protein content normalized. The constant finding of hyperproteinorrhachia in all these patients suggests that a high CSF protein content may be the underlying cause of hydrocephalus through a speculative mechanism of decreased CSF resorption.

Clinical and Molecular Genetics of Inherited Hydrocephalus*

ABSTRACTCongenital hydrocephalus has a broad spectrum of etiology and has not been elucidated in terms of pathogenesis or mechanism of hydrocephalus. Recent advance of molecular genetics disclosed the genetic defects of X‐linked hydrocephalus (HSAS), MASA syndrome and X‐linked spastic paraplegia (SPGI), characterized by mutations in LICAM, a gene coding for a neural cell adhension molecule. Meanwhile, genetic heterogeneity in X‐linked hydrocephalus has been pointed out; linkage to markers within Xq27.3. We reviewed inherited hydrocephalus and chromosomal aberrations with hydrocephalus because fibroblasts from patients with these disorders may be useful for a molecular genetic approach to inherited hydrocephalus. Animal models of congenital hydrocephalus are also very important for a comparative mapping analysis between mice and human. We have tried to clone a candidate gene of hydrocephalus using fibroblasts which show a de nove chromosomal aberration [t(4;16)(q35;q22.1)], because the synteny conservation locus for mouse hydrocephalus‐3 (hy‐3) gene is suggested to be located in the long arm of human chromosome 16. A rearranged band of 1.2 Mb was detected by Pulse‐Field Gel Electrophoresis (PFGE) with Not I digestion using the calretinin probe. It may exist within 1.2 Mb distal apart from calretinin gene. Further analysis is carried out in order to clone this candidate gene of congenital hydrocephalus.

Hydrocephalus following iophendylate injection myelography with spontaneous resolution: Case report and review

A 62-year-old patient developed severe adhesive spinal arachnoiditis and hydrocephalus with papilledema following iophendylate injection myelography. Papilledema and hydrocephalus resolved spontaneously. The possible mechanism for hydrocephalus is discussed and the literature reviewed.

Mechanisms of hydrocephalus in cerebral cysticercosis: implications for therapy.

Patients with hydrocephalus secondary to cerebral cysticercosis are a highly heterogeneous group. The mechanisms of hydrocephalus in these patients are multiple. Intraventricular cysts may be found in the 3rd and 4th ventricles, the sylvian aqueduct, and the foramen of Monro. Intraventricular cysts can be suspected when the 3rd and 4th ventricles or aqueduct remain enlarged despite shunting. Intraventricular contrast medium demonstrates the presence of the parasites. The intraventricular cysts should be removed surgically. Hydrocephalus due to cisternal cysticercosis can be diagnosed by isotope cisternography. These patients should receive shunts, but the long term prognosis is probably poor. Guidelines for the management of hydrocephalus due to cysticercosis are suggested.

Mechanisms of hydrocephalus in cerebral cysticercosis

Mechanisms of hydrocephalus in cerebral cysticercosis

The Chiari malformations of the posterior fossa and their relation to hydrocephalus.

The classification of the developmental malformations of the posterior fossa associated with hydrocephalus proposed by Chiari is systematic and comprehensive. It is based upon the relative position of cerebellum and brainstem in relation to the foramen magnum and the upper cervical canal. Types I to II are degrees of a similar abnormality in which a conical deformity of the posterior midline cerebellum and the elongated brainstem lie at or below the foramen magnum. In the Type IV deformity, in contrast, the cerebellum and brainstem lie fully within the posterior fossa and their position in relation to the foramen magnum is normal. The most common example of this type is probably the Dandy-Walker malformation, in which a defect in the inferior vermis is congruent with a ventriculocele of the enlarged fourth ventricle. The Chiari malformations are generally associated with hydrocephalus. The most comprehensive and coherent theory of the origin of these malformations is that abnormal hydrostatic forces, acting principally during the second and early third trimesters of gestation, provide the mechanism of posterior fossa deformity. Morphological evidence indicates that posterior fossa structures in Types I to III are "pushed down" from above. Radio-isotope dilution studies suggest that the mechanism of hydrocephalus in Types I to III is overproduction of cerebrospinal fluid (CSF); initially there may be no obstructive component. In those cases without spina bifida, ventricular enlargement should occur early and be greatest in the forebrain, driving the tentorium and posterior fossa structures downward. Where there is a fistulous communication between the ventricular system and the amniotic cavity via a spina-bifida defect, a pressure gradient between intracranial and spinal compartments may be sufficient to account for downward displacement of posterior fossa structures. In this instance ventricular enlargement may occur only after cerebellar impaction causes frank obstruction to the flow of cerebrospinal fluid. In the Dandy-Walker malformation, the mechanism of hydrocephalus is probably obstruction to flow of cerebrospinal fluid through the roof of the fourth ventricle. Enlargement of the fourth ventricle is sufficient not only to compress the cerebellum and give rise to the inferior vermal defect, but also to offset forces above the tentorium and prevent its caudal displacement from the parietal region.

A case of neuro-cutaneous melanosis.

An 1-month-old male infant with bathing trunk nervus and hydrocephalus is described. He died of hydrocephalus communicans with purulent meningitis. At autopsy leptomeningeal melanosis was found, and the diagnosis of neuro-cutaneous melanosis was made. The detailed histological findings of the central nervous system in this case are presented here. There have been no reports about the electron microscopic observation in this condition. The pathogenesis of this disease and the mechanism of hydrocephalus are discussed on the basis of histological findings.

Concerning the mechanism of hydrocephalus in the progeny of Trypan Blue treated rats.

1. Seven foetal rats aged 19-21 days were examined in serial section to investigate the lesion responsible for the hydrocephalus in the offsprings of Trypan Blue injected mothers. 2. In four, lesions of the aqueduct were found. Three were examples of atresia which extended into the third ventricle. The fourth showed stenosis. 3. The obstruction in one of the remainder was probably due to impaction of the cerebellum and medulla oblongata in the foramen magnum associated with a spinal myelocele. 4. No satisfactory explanation for the hydrocephalus could be offered in the other two animals.