Choroid plexus hyperplasia: surgical treatment and immunohistochemical results. Case report

Imaging of supratentorial intraventricular masses in children:a pictorial review- part 1

PURPOSE

This article is the first in a two-part series designed to provide a comprehensive overview of the range of supratentorial intraventricular masses observed in children. Our primary objective is to discuss the diverse types of intraventricular masses that originate not only from cells within the choroid plexus but also from other sources.

METHODS

In this article, we review relevant epidemiological data, the current genetics/molecular classification as outlined in the fifth edition of the World Health Organization's Classification of tumours of the Central Nervous System and noteworthy imaging findings. We conduct an exhaustive analysis of primary choroid plexus tumours as well as other conditions such as choroid plexus hyperplasia, choroid plexus cyst, choroid plexus xanthogranuloma, atypical teratoid rhabdoid tumour, meningioma, arteriovenous malformation and metastasis.

RESULTS

We comprehensively evaluated each supratentorial intraventricular mass, providing an in-depth analysis of their unique clinical and histological characteristics. The fifth edition of the World Health Organization Classification of Tumours of the Central Nervous System introduces major modifications. These important changes could potentially have a profound impact on the management strategies and subsequent outcomes of these tumours.

CONCLUSION

Intraventricular masses in children can arise from various sources. Surgical intervention is key for certain supratentorial intraventricular masses in paediatric patients, with preoperative neuroimaging essential to decide the best treatment approach, surgical or otherwise, as some cases may not require surgery.

Choroid plexus epithelium and its role in neurological diseases

Choroid plexus epithelial cells can secrete cerebrospinal fluid into the ventricles, serving as the major structural basis of the selective barrier between the neurological system and blood in the brain. In fact, choroid plexus epithelial cells release the majority of cerebrospinal fluid, which is connected with particular ion channels in choroid plexus epithelial cells. Choroid plexus epithelial cells also produce and secrete a number of essential growth factors and peptides that help the injured cerebrovascular system heal. The pathophysiology of major neurodegenerative disorders like Alzheimer's disease, Parkinson's disease, as well as minor brain damage diseases like hydrocephalus and stroke is still unknown. Few studies have previously connected choroid plexus epithelial cells to the etiology of these serious brain disorders. Therefore, in the hopes of discovering novel treatment options for linked conditions, this review extensively analyzes the association between choroid plexus epithelial cells and the etiology of neurological diseases such as Alzheimer's disease and hydrocephalus. Finally, we review CPE based immunotherapy, choroid plexus cauterization, choroid plexus transplantation, and gene therapy.

The pathogenesis of idiopathic normal pressure hydrocephalus based on the understanding of AQP1 and AQP4

Idiopathic normal pressure hydrocephalus (iNPH) is a neurological disorder without a recognized cause. Aquaporins (AQPs) are transmembrane channels that carry water through cell membranes and are critical for cerebrospinal fluid circulation and cerebral water balance. The function of AQPs in developing and maintaining hydrocephalus should be studied in greater detail as a possible diagnostic and therapeutic tool. Recent research indicates that patients with iNPH exhibited high levels of aquaporin 1 and low levels of aquaporin 4 expression, suggesting that these AQPs are essential in iNPH pathogenesis. To determine the source of iNPH and diagnose and treat it, it is necessary to examine and appreciate their function in the genesis and maintenance of hydrocephalus. The expression, function, and regulation of AQPs in iNPH are reviewed in this article, in order to provide fresh targets and suggestions for future research.

Role of aquaporins in hydrocephalus: what do we know and where do we stand? A systematic review

INTRODUCTION

Glymphatic fluid circulation may be considered the lymphatic system of the brain and the main role of such system seems to be played by aquaporins (AQPs), a family of proteins which regulates water exchange, in particular AQP4 and 1. Alterations of glymphatic fluid circulation through AQPs variations are now emerging as central elements in the pathophysiology of different brain conditions, like hydrocephalus. This systematic review provides an insight about the role of AQPs in hydrocephalus establishment and compensation, investigating their possible role as diagnostic tools or therapeutic targets.

METHODS

PubMed database was screened searching for the relevant existing literature in English language published until February 29th 2020, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement.

RESULTS

A total of 40 articles met the inclusion criteria for our systematic analysis. AQP4 resulted the most studied water channel, followed by AQP1. The changes in cerebrospinal fluid (CSF), brain parenchyma and choroid plexus (CP) in different hydrocephalus type were analyzed. Moreover, important pharmacological interactions regarding AQP and molecules or conditions were discussed. A very interesting result is the general consensus on increase of AQP4 in hydrocephalic patients, unless in patients suffering from idiopathic normal pressure hydrocephalus, where AQP4 shows a tendency in reduction.

CONCLUSION

AQP seem to play a central role in the pathophysiology of hydrocephalus and in its compensation mechanisms. Further studies are required to definitively establish their precise roles and their quantitative changes to allow their utilization as diagnostic tools or therapeutic targets.

Complex Management of Hydrocephalus Secondary To Choroid Plexus Hyperplasia

BACKGROUND

Hyperplasia of the choroid plexus represents a rare cause of communicating hydrocephalus in children. Recent work has associated such disease with genetic abnormalities (such as perturbations in chromosome 9). Given such extensive cerebrospinal fluid (CSF) overproduction, patients with choroid plexus hyperplasia often fail CSF diversion and therefore require adjuvant interventions.

CASE DESCRIPTION

We present the case of a male infant with a ventriculoperitoneal shunt and radiographic choroid hyperplasia who presented to our institution with a massive abdominal hydrocele caused by an inability to absorb the significant amount of CSF drainage into the abdomen.

CONCLUSION

The child was treated with an endoscopic third ventriculostomy and choroid plexus coagulation; however, he still required CSF diversion via a ventriculoatrial shunt. A genetic workup showed tetraploidy of chromosome 9. We discuss criteria for selection of treatment strategies, including endoscopic third ventriculostomy with choroid plexus coagulation and/or CSF diversion, that may prevent the need for re-operation in select patients with hydrocephalus due to choroid plexus hyperplasia.

Benign Postnatal Outcome after Prenatal Diagnosis of Fetal Ventriculomegaly with Choroid Plexus Hyperplasia: A Case Report

Prenatal counselling following the diagnosis of fetal ventriculomegaly is challenging. Fetal MRI (magnetic resonance imaging) can be helpful in characterizing ventriculomegaly severity and associated anomalies, hence contributing to prognosis establishment. Choroid plexus hyperplasia (CPH) is a rare entity characterized by enlargement of the choroid plexuses, usually progressing to severe hydrocephalus with an associated poor outcome. We present a case of CPH diagnosed by fetal MRI at 23 weeks of gestation following referral for ventriculomegaly. The pregnancy was carried to term and the child was monitored clinically and radiologically. Despite the persistence of enlarged choroid plexuses, the ventricular size has progressively decreased, and at the 4-year follow-up the child presented normal psychomotor development. This case highlights the added value of MRI in prenatal diagnosis of fetal ventriculomegaly and its management. The unusual benign outcome in this case can be considered for parental counselling when faced with a fetus with similar findings.

9p24 triplication in syndromic hydrocephalus with diffuse villous hyperplasia of the choroid plexus

Hydrocephalus, a disorder of impaired cerebrospinal fluid (CSF) homeostasis, often results from an imbalance between CSF production and reabsorption. Rarely, hydrocephalus is the consequence of CSF hypersecretion in the context of diffuse villous hyperplasia of the choroid plexus (DVHCP). The limited genetic information in previously reported cases suggests a high prevalence of gains of Chromosome 9p in this disease, although the critical genes involved in DVHCP pathogenesis have not been identified. Here, we report a patient with syndromic hydrocephalus with DVHCP associated with a novel 9p24.3-11.2 triplication and 15q13.2-q13.3 microdeletion. We review the clinical, radiological, and pathological features of DVHCP, as well as its surgical management. A better understanding of the genetic basis of DVHCP could spur the development of rational, targeted nonsurgical hydrocephalus treatments.

Expression of Aquaporin 1 and 4 in the Choroid Plexus and Brain Parenchyma of Kaolin-Induced Hydrocephalic Rats

Objective

Aquaporin (AQP) is a recently discovered protein that regulates water homeostasis. The present study examines changes in AQP 1 and 4 in kaolin induced experimental hydrocephalic rats to elucidate the pathophysiology of water homeostasis in the disease.

Methods

Hydrocephalus was induced by percutaneous intracisternal injection of kaolin. The brain parenchyma and choroid plexus were obtained at 3, 7, 14 and 30 days after injection. Protein expressions of AQP 1 and 4 were measured by western blot, immunohistochemistry (IHC) and immunofluorescence (IF) stains.

Results

In the choroid plexus of the kaolin-induced hydrocephalus group, AQP 1 expression identified by western blot exhibited sharp decrease in the early stage (55% by the 3rd day and 22% by the 7th day), but indicated a 2.2-fold increase in the later stage (30th day) in comparison with control groups. In the parenchyma, a quantitative measurement of AQP 4 expression revealed variable results on the 3rd and 7th days, but indicated expression 2.1 times higher than the control in the later stage (30th day). In addition, the IHC and IF findings supported the patterns of expression of AQP 1 in the choroid plexus and AQP 4 in the parenchyma.

Conclusion

Expression of AQP 1 decreased sharply in the choroid plexus of acute hydrocephalus rats and increased at later stages. Expression of AQP 4 in the brain parenchyma was variable in the early stage in the hydrocephalus group, but was higher than in the control in the later stage. These findings suggest a compensating role of AQPs in water physiology in hydrocephalus.

Aquaporins in Brain Edema and Neuropathological Conditions

The aquaporin (AQP) family of water channels are a group of small, membrane-spanning proteins that are vital for the rapid transport of water across the plasma membrane. These proteins are widely expressed, from tissues such as the renal epithelium and erythrocytes to the various cells of the central nervous system. This review will elucidate the basic structure and distribution of aquaporins and discuss the role of aquaporins in various neuropathologies. AQP1 and AQP4, the two primary aquaporin molecules of the central nervous system, regulate brain water and CSF movement and contribute to cytotoxic and vasogenic edema, where they control the size of the intracellular and extracellular fluid volumes, respectively. AQP4 expression is vital to the cellular migration and angiogenesis at the heart of tumor growth; AQP4 is central to dysfunctions in glutamate metabolism, synaptogenesis, and memory consolidation; and AQP1 and AQP4 adaptations have been seen in obstructive and non-obstructive hydrocephalus and may be therapeutic targets.

Development and functions of the choroid plexus-cerebrospinal fluid system

The choroid plexus (ChP) is the principal source of cerebrospinal fluid (CSF), which has accepted roles as a fluid cushion and a sink for nervous system waste in vertebrates. Various animal models have provided insights into how the ChP-CSF system develops and matures. In addition, recent studies have uncovered new, active roles for this dynamic system in the regulation of neural stem cells, critical periods and the overall health of the nervous system. Together, these findings have brought about a paradigm shift in our understanding of brain development and health, and have stimulated new initiatives for the treatment of neurological disease.

Idiopathic cerebrospinal fluid overproduction: case-based review of the pathophysiological mechanism implied in the cerebrospinal fluid production

Cerebrospinal fluid (CSF) overproduction results from either CSF infection or choroid plexus hypertrophy or tumor, with only a single idiopathic case described so far. We report a unique case of a male infant with Crouzon syndrome who presented with intracranial hypertension, caused by up to 4-fold increase in CSF daily production. Conditions related to CSF overproduction, namely central nervous system infections and choroid plexus hypertrophy or tumor, were ruled out by repeated magnetic resonance imaging and CSF samples. Medical therapy failed to reduce CSF production and the patient underwent several shunting procedures, cranial expansion, and endoscopic coagulation of the choroid plexus. This article thoroughly reviews pertinent literature on CSF production mechanisms and possible therapeutic implications.

Bilateral choroid plexus hyperplasia: a case report and management strategies

INTRODUCTION

Choroid plexus hyperplasia (CPH) is a rare cause of cerebrospinal fluid (CSF) overproduction and shunt-resistant hydrocephalus in infants. If treated with a ventriculoperitoneal (VP) shunt, these patients secondarily develop CSF accumulation along the shunt tract and within the peritoneum. The surgical management of this condition is not as clearly defined as in the case of a choroid plexus papilloma or carcinoma.

CASE REPORT

An 8-day-old male patient presented with bulging fontanelle, head circumference = 42 cm (>98th percentile), and cranial ultrasound demonstrating communicating hydrocephalus with enlarged choroid plexuses. A VP shunt was inserted, and secondarily progressive hydrocephalus, shunt tract fluid accumulation, and ascites developed. The infant underwent staged bilateral plexectomy and is tolerating CSF diversion. The pathology confirmed CPH.

DISCUSSION

Of the cases reported in the literature, treatments have included CSF shunting, endoscopic coagulation, and craniotomy with plexectomy. CSF shunting was required in the majority but not all. Only those having undergone bilateral choroid plexectomy have been rendered shunt free.