Overproduction Of Cerebrospinal Fluid Research Articles

Congenital/Primitive Hydrocephalus: Classification, Clinical Aspects, and Rehabilitation Approach

AbstractHydrocephalus is a heterogeneous disorder of cerebrospinal fluid (CSF) flow that leads to abnormal enlargement of the brain ventricles. The prevalence of infant hydrocephalus is approximately one case per 1,000 births. Hydrocephalus occurs due to an imbalance between the production and the absorption of CSF. The causes of hydrocephalus secondary to CSF overproduction are papilloma of the choroid plexus and rarely diffuse hyperplasia of the villi. All the other hydrocephalus forms are secondary to obstruction to normal CSF reabsorption and are also known as obstructive hydrocephalus. According to the location of obstruction, obstructive hydrocephalus can be defined as communicating, when caused by extraventricular obstruction of the CSF flow or decreased resorption of CSF distal to the fourth ventricle in the cisterns of the base or in the subarachnoid spaces, or as not communicating, in case of intraventricular obstruction to fluid flow. There is a third category, common in preterm infants, called external hydrocephalus which is secondary to delayed development of arachnoid function. Hydrocephalus leads to an increase in intraventricular pressure because of the lack of the mechanism regulating the homeostasis of the CSF flow. Increased intraventricular pressure is responsible for the clinical symptoms in affected child. Clinical presentation varies with age. In the neonatal period, prolonged or frequent apneic or bradycardic events, increasing head circumference, presence of sunsetting eyes or upward gaze palsy, evidence of full or tense anterior/posterior fontanelle, and splayed cranial sutures are signs of increased intracranial pressure. In infants, the most common signs are progressive macrocephaly, irritability, nausea/vomiting, headache, gait changes, and regression of developmental milestones. The extent of brain damage depends on the cause that led to hydrocephalus, the patient's age, and the rapidity of onset. The surgical treatment modalities consist of endoscopic ventriculostomy of the third ventricle and ventriculoperitoneal or ventriculoatrial CSF shunt.

Understanding and Modeling the Pathophysiology of Hydrocephalus: In Search of Better Treatment Options

Hydrocephalus is caused by an overproduction of cerebrospinal fluid (CSF), an obstruction of fluid movement, or improper reabsorption. CSF accumulation in the brain’s ventricles causes ventriculomegaly, increased intracranial pressure, inflammation, and neural cell injury. Hydrocephalus can arise from brain trauma, hemorrhage, infection, tumors, or genetic mutations. Currently, there is no cure for hydrocephalus. Treatments like shunting and endoscopic third ventriculostomies are used, but, unfortunately, these therapeutic approaches require brain surgery and have high failure rates. The choroid plexus epithelium (CPe) is thought to be the major producer of CSF in the brain. It is a polarized epithelium that regulates ion and water movement from a fenestrated capillary exudate to the ventricles. Despite decades of research, control of electrolyte movement in the CPe is still not fully understood. This review discusses important transporters on the CPe, how some of these are regulated, and which of them could be potential targets for hydrocephalus treatment. To advance the development of hydrocephalus treatments, physiologically relevant preclinical models are crucial. This review covers some of the current animal and cell culture methods used to study hydrocephalus and highlights the need to develop standardized preclinical models that are used by multiple investigators in order to replicate critical findings and resolve controversies regarding potential drug targets.

Ptpn20 deletion in H-Tx rats enhances phosphorylation of the NKCC1 cotransporter in the choroid plexus: an evidence of genetic risk for hydrocephalus in an experimental study

BackgroundCongenital hydrocephalus occurs with some inheritable characteristics, but the mechanisms of its development remain poorly understood. Animal models provide the opportunity to identify potential genetic causes in this condition. The Hydrocephalus-Texas (H-Tx) rat strain is one of the most studied animal models for investigating the causative genetic alterations and analyzing downstream pathogenetic mechanisms of congenital hydrocephalus.MethodsComparative genomic hybridization (CGH) array on non-hydrocephalic and hydrocephalic H-Tx rats was used to identify causative genes of hydrocephalus. Targeted gene knockout mice were generated by CRISPR/Cas9 to study the role of this gene in hydrocephalus.ResultsCGH array revealed a copy number loss in chromosome 16p16 region in hydrocephalic H-Tx rats at 18 days gestation, encompassing the protein tyrosine phosphatase non-receptor type 20 (Ptpn20), a non-receptor tyrosine phosphatase, without change in most non-hydrocephalic H-Tx rats. Ptpn20-knockout (Ptpn20−/−) mice were generated and found to develop ventriculomegaly at 8 weeks. Furthermore, high expression of phosphorylated Na-K-Cl cotransporter 1 (pNKCC1) was identified in the choroid plexus (CP) epithelium of mice lacking Ptpn20 from 8 weeks until 72 weeks.ConclusionsThis study determined the chromosomal location of the hydrocephalus-associated Ptpn20 gene in hydrocephalic H-Tx rats. The high level of pNKCC1 mediated by Ptpn20 deletion in CP epithelium may cause overproduction of cerebrospinal fluid and contribute to the formation of hydrocephalus in Ptpn20−/− mice. Ptpn20 may be a potential therapeutic target in the treatment of hydrocephalus.

Regulation of Ncbe in the Choroid Plexus of Mice after Hemorrhage‐Induced Hydrocephalus

The choroid plexus (CP) is a small tissue located inside brain ventricles. It is responsible for the production of most of the cerebrospinal fluid (CSF); approximately 500 mL of CSF per day in the adult human [1, 2]. CSF production occurs as a net result of transcellular movement of salt and water, carried out by various cellular transporters.Ncbe is a sodium‐coupled bicarbonate transporter located in the basolateral membrane of the choroid plexus epithelial (CPE) cells. It transports Na+ and HCO3‐ into the cell in exchange for Cl‐. Ncbe is the main sodium loader of the cell and CSF production is probably dependent on this transporter [3].Posthemorrhagic hydrocephalus (PHH) is a pathological state, caused by an accumulation of CSF in the ventricular system following intraventricular hemorrhage. CSF buildup is caused by a disproportion in CSF production and reabsorption. This leads to an expansion of the brain ventricles. Intraventricular hemorrhage (IVH) is known to cause inflammation in the CP, which is coupled to an over‐production of CSF [4‐6].Initially we hypothesized that IVH would stimulate Ncbe in the CPE through increased protein abundance as well as transporter activity. This would lead to increased CSF formation, similar to the response found after treatment with e.g. the cyclic‐AMP agonist forskolin [7]. Our preliminary data, however, suggest that Ncbe abundance is reduced by 24% (n=4, p=0.0329) in mice in the initial stages of PHH and then normalizes.The aim of this study is to investigate which role Ncbe plays in PHH and how Ncbe knock down affects CSF production in both healthy mice and a disease model.An adeno‐associated virus (AAV) shRNA knockdown vector system has been developed to knock down Ncbe gene expression by intracerebroventricular injections. Our preliminary data shows that the CPE cells incorporate the vector when tagged with GFP.We have established an IVH model and recording of CSF secretion rates in mice. Increased CSF formation rate was validated with ventriculo‐cisternal perfusion (data shown in figure). The resulting changes in ventricular volume will be investigated using magnetic resonance imaging (MRI).We propose that Ncbe knock down inhibits CSF production and could potentially target inflammation‐dependent hypersecretion by reducing the availability of the sodium supplying the apical transporters in the CP.

Hydrocephalus in dogs

Hydrocephalus is an excessive accumulation of cerebrospinal fluid (CSF) in the brain. This condition is more common in brachycephalic and toy dog breeds. The diagnosis is based on the interpretation of the data obtained from the anamnesis, the clinical and neurological examination. The confirmation is made by advanced imaging (CT/MRI). Transfontanelar ultrasound is indicated in patients in whom the fontanels remain partially open. The differential diagnosis is required to exclude other encephalopathies. The medication aims to reduce CSF overproduction and improve neurological signs. Surgery (ventriculoperitoneal shunt) is a long-term option in patients who do not respond to medication.

Shunt Revision to Ventriculoatrial Shunt Due to Long-Term Abdominal Distension Complicated by Neonatal Necrotizing Enterocolitis and Cerebrospinal Fluid Overproduction after Ventriculoperitoneal Shunt for the Management of Post-Hemorrhagic Hydrocephalus: A Case Report

Shunt Revision to Ventriculoatrial Shunt Due to Long-Term Abdominal Distension Complicated by Neonatal Necrotizing Enterocolitis and Cerebrospinal Fluid Overproduction after Ventriculoperitoneal Shunt for the Management of Post-Hemorrhagic Hydrocephalus: A Case Report

Choroid Plexus Papilloma with Dandy Walker Variant: Co-existence or Association- A Case Report

Choroid plexus tumors are rare intracranial tumors which account for 0.4-0.6% of all brain tumors. Choroid plexus tumors represent a spectrum of neoplasms derived from papillary epithelium of normal choroid plexus, including well-differentiated papilloma (WHO grade I), intermediate form as atypical Choroid Plexus Papilloma (WHO grade II) and highly aggressive choroid plexus carcinomas (WHO grade III). Though rare, it is responsible for the communicating hydrocephalus in children due to overproduction of cerebrospinal fluid. Due to advances in molecular biology and better understanding of the tumorigenesis of choroid plexus papilloma, now it is established that several genetic syndromes and central nervous sytem abnormalities are associated with this tumor. Here, we reported a case of a 10 months old child who presented with sudden deterioration of consciousness level and after thorough evaluation, diagnosed as a case of Choroid Plexus Papilloma with Dandy Walker Variant. Till date, this is the first reported case of the association/ co-existence of such two conditions which needs further evaluation.
 Bangladesh Med J. 2017 May; 46 (2): 61-65

Characterizing the Expression of TRPV4 in the Choroid Plexus Epithelia as a Prospective Component in the Development of Hydrocephalus in the Gas8GT Juvenile Mouse Model

Maintenance of homeostatic cerebrospinal fluid (CSF) secretion and absorption is essential for basic neurologic function. The choroid plexus epithelia, which is thought to produce the majority of the CSF, are among the most secretory of all epithelia. However, the control of this secretory process is poorly described. In diseased states such as hydrocephalus, where this homeostasis is disrupted, patients often experience symptoms such as cognitive impairment, motor/stability issues, and incontinence, among others. Current treatment for hydrocephalus is limited to surgically invasive shunting procedures which often fail and need revising – particularly in pediatric cases. In order to study the mechanism of this disease, a knock out mouse line of the Growth Arrest Specific 8 (Gas8) allele was generated. Loss of function of the Gas8 allele induces ciliopathy similar to Primary Ciliary Dyskinesia (PCD) in humans, with one of the symptoms being severe perinatal hydrocephalus. The disease progression in the mutant (−/−) mice is from postnatal day 0 (P0) to postnatal day 12–16 (P12–16), which makes this an excellent model to study pediatric/juvenile hydrocephalus. It is believed that one of the mechanisms of pediatric hydrocephalus is the overproduction of CSF by the choroid plexus (CP) epithelial cells that line the ventricles of the brain. The protein of interest to this research is the non‐specific cation channel, Transient Receptor Potential Vanilloid 4 (TRPV4), which has been shown to be activated by multiple stimuli including osmotic and pressure changes as well as by prostanoid metabolites. Activation of TRPV4 results in Ca2+ influx through the channel resulting in changes in intracellular signaling including the secondary activation of Ca2+‐stimulated ion transporters. Consistent with other studies, TRPV4 is localized to the apical membrane of the CP epithelial tissue in the Wild Type Gas8 mice. Preliminary data on the juvenile Gas8 mice indicate that TRPV4 is overexpressed in CP epithelia, ependymal cells and in the sub‐ventricular zone in the mutants as their hydrocephalus progresses as compared to the wild type (+/+) and heterozygous (+/−) animals. This suggests that antagonistic compounds of the TRPV4 channel have the potential to reduce hydrocephalus in the Gas8 model. Successfully targeting the molecular mechanisms for hydrocephalus in rodent models can provide a promising base for preclinical studies aimed at developing pharmaceutical agents to treat this disease.Support or Funding InformationFunding: Grants from the Hydrocephalus Association and the Department of Defense Office of the Congressionally Directed Medical Research Programs (CDMRP).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Pseudotumor Cerebri and Glymphatic Dysfunction.

In contrast to virtually all organ systems of the body, the central nervous system was until recently believed to be devoid of a lymphatic system. The demonstration of a complex system of paravascular channels formed by the endfeet of astroglial cells ultimately draining into the venous sinuses has radically changed this idea. The system is subsidized by the recirculation of cerebrospinal fluid (CSF) through the brain parenchyma along paravascular spaces (PVSs) and by exchanges with the interstitial fluid (IF). Aquaporin-4 channels are the chief transporters of water through these compartments. This article hypothesizes that glymphatic dysfunction is a major pathogenetic mechanism underpinning idiopathic intracranial hypertension (IIH). The rationale for the hypothesis springs from MRI studies, which have shown many signs related to IIH without evidence of overproduction of CSF. We propose that diffuse retention of IF is a direct consequence of an imbalance of glymphatic flow. This imbalance, in turn, may result from an augmented flow from the arterial PVS into the IF, by impaired outflow of the IF into the paravenous spaces, or both. Our hypothesis is supported by the facts that (i) visual loss, one of the main complications of IIH, is secondary to the impaired drainage of the optic nerve, a nerve richly surrounded by water channels and with a long extracranial course in its meningeal sheath; (ii) there is a high association between IIH and obesity, a condition related to paravascular inflammation and lymphatic disturbance, and (iii) glymphatic dysfunction has been related to the deposition of β-amyloid in Alzheimer’s disease. We conclude that the concept of glymphatic dysfunction provides a new perspective for understanding the pathophysiology of IIH; it may likewise entice the development of novel therapeutic approaches aiming at enhancing the flow between the CSF, the glymphatic system, and the dural sinuses.

Low cerebrospinal fluid protein in prepubertal children with idiopathic intracranial hypertension.

To evaluate a clinical observation that prepubertal children with idiopathic intracranial hypertension (IIH) have low cerebrospinal fluid (CSF) protein levels compared to healthy children and pubertal patients with IIH. The medical records of prepubertal and pubertal IIH patients and controls seen in the pediatric neuro-ophthalmology clinic at Duke between 2003 and 2013 were retrospectively reviewed. The control group consisted of children who had normal intracranial pressure on lumbar puncture performed to evaluate for headaches or anomalous-looking optic nerves. The records were analyzed with attention to demographic characteristics, clinical presentation, course, and lumbar puncture results. A total of 23 prepubertal children with IIH (age range, 0.75-13 years), 16 pubertal patients with IIH (age range, 13-21 years), and 12 controls (age range 3-14 years) were included. CSF analysis revealed that prepubertal children with IIH had significantly lower CSF protein levels (17.3 ± 5.7 mg/dL) compared to pubertal subjects with IIH (23.4 ± 8.4 mg/dL; P = 0.019) or healthy controls (23.5 ± 6.4 mg/dL; P = 0.011). Furthermore, 9 of 23 prepubertal IIH patients (39%) had abnormally low CSF protein level (<15 mg/dL), compared to zero pubertal IIH patients (P = 0.005) and zero controls (P = 0.015). Acetazolamide increased CSF protein level in 100% of patients who underwent repeat lumbar puncture after starting the medication (average increase, 10.3 ± 6.6 mg/dL). Low CSF protein level may have diagnostic utility as a biomarker for prepubertal IIH. Furthermore, this finding suggests that some cases of prepubertal IIH may be caused by CSF overproduction rather than decreased CSF resorption.

A Case of Difficult Management of Fluid-electrolyte Imbalance in Choroid Plexus Papilloma

A 22-month-old boy presented with nausea and gradual deterioration of gait disturbance. Computed tomography (CT) demonstrated an intraventricular mass lesion in the right lateral ventricle. He was referred to our department 3 weeks after onset. Acute hydrocephalus gradually proceeded 4 days after admission, and external ventricular drainage (EVD) was performed. EVD revealed cerebrospinal fluid (CSF) overproduction (800-1,500 mL/day) under constant pressure of 10 cm H2O above external auditory meatus. Magnetic resonance imaging showed a multi-lobular mass in the inferior horn of the right lateral ventricle. A choroid plexus tumor was suspected. The ratio of blood urea nitrogen:creatinine (BUN:Cre) remained between 30 and 40, and hemoglobin was between 14.0-17.0 mg/dL, suggesting marked dehydration. Serum sodium varied between 117 and 140 mmol/L, and serum potassium between 2.2 mmol/L and 6.9 mmol/L. The amount of EVD was unstable and fluid balance management was difficult. Hypotonic fluid with sodium chloride supplement was used to adjust the fluid and electrolyte imbalance. Surgical removal of the tumor was performed 6 days after EVD and tumor was grossly and totally removed. The high BUN:Cre ratio decreased to about 15 and hemoglobin recovered to 7.5-9.0 mg/dL after removal. Electrolytes returned to the normal range. Overproduction of CSF also markedly improved to < 300 mL/day. Histopathological examination diagnosed choroid plexus papilloma.We experienced a case of choroid plexus papilloma associated with fluid-electrolyte imbalance due to over-drainage after EVD, which could not be effectively controlled before tumor removal. Cautious fluid management and emergent surgical resection might be required to manage the overproduction of CSF and fluid-electrolyte imbalance.

Choroid plexus papilloma of the third ventricle: A rare infantile brain tumor

Choroid plexus papilloma (CPP) represents an uncommon pediatric brain tumor with an overall incidence less than 1% of all intracranial tumors. Most of these tumors occur in the lateral ventricles in neonates. Third ventricular location is uncommon, limited to a few case reports. These highly vascular tumors retain the physiological function of choroid plexus and thus lead to overproduction of cerebrospinal fluid (CSF), besides obstructing the CSF pathway. Imaging is fairly sensitive and specific in affording the diagnosis of this tumor. Surgical approaches differ according to the site of tumor and aim is complete removal of tumor. We present an interesting report of an infant who presented to our department for cranial sonography that lead to suspicion of this tumor, later confirmed by other imaging modalities and histopathology.

Failure of peritoneal and gallbladder shunts in a child with craniopharyngioma

A 1-year-old girl with craniopharyngioma required external drainage of 40-50 mL/h of cerebrospinal fluid (CSF) after biopsy and cyst fenestration. She developed CSF ascites following insertion of a ventriculoperitoneal (VP) shunt and a distended painful gallbladder following ventriculogallbladder shunt insertion. Revision to a ventriculoatrial shunt was required. This is the first time a craniopharyngioma has been reported to cause increased CSF production. The potential mechanisms of CSF overproduction and the difficulties managing the large volume of CSF in a young child are discussed.

Catastrophic electrolyte imbalance caused by excessive production and overdrainage of cerebrospinal fluid in an infant with choroid plexus papilloma

Choroid plexus papilloma (CPP), a neoplasm of choroid plexus in the cerebral ventricles, is usually accompanied by hydrocephalus. Obstruction of cerebrospinal fluid (CSF) pathways by the neoplasm may contribute to the development of hydrocephalus, but overproduction of CSF from the tumor is also a major factor in its development [1, 2]. In fact, overproduction of CSF is a unique phenomenon of tumors and of choroid plexus hyperplasia [3]. The chemical and osmotic composition of CSF is different from that of plasma. The sodium content of CSF is nearly identical to that of plasma, but the level of potassium in CSF is less than the level in plasma [4]. Infusions of hypotonic saline with physiologic potassium supplements are commonly used to maintain volume and electrolyte homeostasis in infants and children. If overlooked, this common practice can lead to a severe electrolyte imbalance in patients with CPP when excessive CSF is drained for a short period. Case report

Research advances on associated genes and pathogenesis of hydrocephalus

Hydrocephalus is a common medical condition characterized by abnormalities in the secretion,circulation or resorption of cerebrospinal fluid (CSF), resulting in ventricular dilatation. The pathogenetic mechanism for the hydrocephalus is attributed to: the overproduction of CSF by the choroid plexus; the defect in CSF absorption and obstruction of CSF flow in the cerebral ventricles. However, the underlying etiology is poorly understood. With the development of genetic engineering, a growing body of evidence indicates that genetic factors play an essential role in the pathogenesis of hydrocephalus. It is the aim of this review to summarize these findings.

Single-stage bilateral choroid plexectomy for choroid plexus papilloma in a patient presenting with high cerebrospinal fluid output

Cerebrospinal fluid overproduction resulting in communicating hydrocephalus is observed in patients who have choroid plexus papilloma or choroid plexus carcinoma. Less often, patients with these conditions have diffuse villous hyperplasia. Prior studies report CSF production greater than 3 L per day in these patients. These patients are treated with CSF shunting or by either unilateral choroid plexectomy or staged bilateral choroid plexectomy. The authors present a patient who had a number of congenital anomalies and a karyotype that revealed balanced translocations, 5 to 7 and 9 to 11. She presented with hydrocephalus and had CSF production of 5 L per day, greater output than ever previously reported. She was treated with a single-stage bilateral choroid plexectomy. Histopathological analysis revealed a bilateral choroid plexus papilloma. Postoperatively, the patient responded well clinically and showed radiographic improvement of her hydrocephalus. Bilateral choroid plexus papilloma has been reported in the literature as a cause for neonatal and congenital hydrocephalus. It can result in high CSF output and can be successfully treated with a single-stage bilateral choroid plexectomy. Further studies are ongoing to identify genes involved in embryogenesis of the choroid plexus.

Multiple Primary Cilia Modulate the Fluid Transcytosis in Choroid Plexus Epithelium

Functional defects in cilia are associated with various human diseases including congenital hydrocephalus. Previous studies suggested that defects in cilia not only disrupt the flow of cerebrospinal fluid (CSF) generated by motile cilia in ependyma lining the brain ventricles, but also cause increased CSF production at the choroid plexus. However, the molecular mechanisms of CSF overproduction by ciliary dysfunction remain elusive. To dissect the molecular mechanisms, choroid plexus epithelial cells (CPECs) were isolated from porcine brain. These cells expressed clusters of primary cilia on the apical surface. Deciliation of CPECs elevated the intracellular cyclic AMP (cAMP) levels and stimulated basolateral-to-apical fluid transcytosis, without detrimental effects on other morphological and physiological features. The primary cilia possessed neuropeptide FF (NPFF) receptor 2. In deciliated cells, the responsiveness to NPFF was reduced at nanomolar concentrations. Furthermore, CPECs expressed NPFF precursor along with NPFFR2. An NPFFR antagonist, BIBP3226, increased the fluid transcytosis, suggesting the presence of autocrine NPFF signaling in CPECs for a tonic inhibition of fluid transcytosis. These results suggest that the clusters of primary cilia in CPECs act as a sensitive chemosensor to regulate CSF production.

Choroid plexus hyperplasia: surgical treatment and immunohistochemical results

Diffuse villous hyperplasia of the choroid plexus is a rare but potential source of nonobstructive hydrocephalus. In addition to discussing the authors' staged surgical approach and medical management decisions in a patient with this rare and challenging condition, immunohistochemical studies of the choroid plexus epithelium are presented to examine the pathophysiological factors involved in abnormal cerebrospinal fluid (CSF) production in this disease. The patient, a 15-month-old girl born at 36 weeks' gestation, underwent a bilateral craniotomy with resection of the choroid plexus to treat her villous hyperplasia. Immunohistochemical studies of the resected choroid plexus were conducted for the purpose of examining the carbonic anhydrase II (CAII) enzyme and the aquaporin 1 (AQP1) membrane protein. Results were compared with immunohistochemical studies conducted in a small series of autopsy specimens of normal human choroid plexuses. There was no change in the immunoreactivity of CAII in the patient with villous hyperplasia compared with normal controls, whereas AQP1 immunoreactivity was significantly weaker in the patient compared with normal controls. Postoperatively, the patient's CSF overproduction resolved and her neurological symptoms improved over time. Shunting techniques and presently available pharmaceutical treatments alone do not provide adequate treatment of high-output CSF conditions. Surgical removal of the affected choroid plexus is a feasible and effective treatment. Results of the immunohistochemical studies reported here support the suggestion that the CAII enzyme is retained in villous hyperplasia of the choroid plexus. However, there appears to be decreased expression and perhaps downregulation of AQP1 in villous hyperplasia compared with normal choroid plexus. Future studies may elucidate the significance of these observations.

Abnormalities in Head Size

Abnormalities in Head Size

The role of endoscopic choroid plexus coagulation in the surgical management of bilateral choroid plexuses hyperplasia

Bilateral choroid plexus hyperplasia is a rare condition often associated with cerebrospinal fluid (CSF) overproduction. CSF overproduction is usually so high that the placement of a CSF ventriculoperitoneal shunt almost always results in progressive ascites leading to the necessity of removing the inserted shunt device. A direct surgical treatment of the hyperplastic choroid plexuses is then mandatory. Endoscopic coagulation of the choroid plexuses has been recently proposed as an alternative to open surgical plexectomy. However, the effectiveness of the procedure in controlling CSF overproduction is still debated. We report a case of bilateral choroid plexus hyperplasia in which an extensive bilateral endoscopic coagulation of the choroid plexuses failed to reduce the CSF formation rate sufficiently. A one-stage bilateral open surgical plexectomy was performed. The procedure succeeded to control CSF overproduction. Intraoperative blood loss during the surgical removal of the choroid plexuses was significantly reduced due to the previous coagulation of their surface. On these grounds, we suggest that endoscopic choroid plexuses coagulation, even when failing to normalize CSF production, may still be considered as a valid adjuvant procedure in the management of this condition.