Fourth Ventricle Outlet Obstruction Research Articles

Tetraventricular noncommunicating hydrocephalus: Case report and literature review.

Background: Tetraventricular hydrocephalus is a common presentation of communicating hydrocephalus. Conversely, cases with noncommunicating etiology impose a diagnostic challenge and are often neglected and underdiagnosed. Herein, we present a review of literature for clinical, diagnostic, and surgical aspects regarding noncommunicating tetrahydrocephalus caused by primary fourth ventricle outlet obstruction (FVOO), illustrating with a case from our service.Methods: We performed a research on PubMed database crossing the terms “FVOO,” “tetraventriculomegaly,” and “hydrocephalus” in English. Fifteen articles (a total of 34 cases of primary FVOO) matched our criteria and were, therefore, included in this study besides our own case.Results: Most cases presented in adulthood (47%), equally divided between male and female. Clinical presentation was unspecific, commonly including headache, nausea, and dizziness as symptoms (35.29%, 21.57%, and 9.80%, respectively), with ataxic gait (65%) and papilledema (40%) being the most frequent signs. MRI and CT were the imaging modalities of choice (11 patients each), often associated with CSF flow studies, such as cine MRI and CT ventriculogram. Endoscopic third ventriculostomy (ETV) was both the most popular and effective surgical approach (50.85% of cases, with 18.91% of recurrence) followed by ventricle-peritoneal shunt (16.95% of patients, 23.0% of recurrence).Conclusion: FVOO stands for a poorly understood etiology of noncommunicating tetrahydrocephalus. With the use of ETV, these cases, once hopeless, had its morbimortality and recurrence reduced greatly. Therefore, its suspicion and differentiation from other forms of tetrahydrocephalus can improve its natural course, reinforcing the importance of its acknowledgment.

Fourth ventricle roof angle as a measure of fourth ventricle bowing and a radiographic predictor of brainstem dysfunction in Chiari malformation type I.

Chiari malformation type I (CM-I) is a congenital and developmental abnormality that results in tonsillar descent 5 mm below the foramen magnum. However, this cutoff value has poor specificity as a predictor of clinical severity. Therefore, the authors sought to identify a novel radiographic marker predictive of clinical severity to assist in the management of patients with CM-I. The authors retrospectively reviewed 102 symptomatic CM-I (sCM-I) patients and compared them to 60 age-matched normal healthy controls and 30 asymptomatic CM-I (aCM-I) patients. The authors used the fourth ventricle roof angle (FVRA) to identify fourth ventricle "bowing," a configuration change suggestive of fourth ventricle outlet obstruction, and compared these results across all three cohorts. A receiver operating characteristic (ROC) curve was used to identify a predictive cutoff for brainstem dysfunction. Binary logistic regression was used to determine whether bowing of the fourth ventricle was more predictive of brainstem dysfunction than tonsillar descent, clival canal angle, or obex position in aCM-I and sCM-I patients. The FVRA had excellent interrater reliability (intraclass correlation 0.930, 95% CI 0.905-0.949, Spearman r2 = 0.766, p < 0.0001). The FVRA was significantly greater in the sCM-I group than the aCM-I and healthy control groups (59.3° vs 41.8° vs 45.2°, p < 0.0001). No difference was observed between aCM-I patients and healthy controls (p = 0.347). ROC analysis indicated that an FVRA of 65° had a specificity of 93% and a sensitivity of 50%, with a positive predictive value of 76% for brainstem dysfunction. FVRA > 65° was more predictive of brainstem dysfunction (OR 5.058, 95% CI 1.845-13.865, p = 0.002) than tonsillar herniation > 10 mm (OR 2.564, 95% CI 1.050-6.258, p = 0.039), although increasing age was also associated with brainstem dysfunction (OR 1.045, 95% CI 1.011-1.080, p = 0.009). A clival canal angle < 140° (p = 0.793) and obex below the foramen magnum (p = 0.563) had no association with brainstem dysfunction. The authors identified a novel radiographic measure, the FVRA, that can be used to assess fourth ventricular bowing in CM-I and is more predictive of brainstem dysfunction than tonsillar herniation. The FVRA is easy to measure, has excellent interrater variability, and can be a reliable universal radiographic measure. The FVRA will be useful in further describing CM-I radiographically and clinically by identifying patients more likely to be symptomatic as a result of brainstem dysfunction.

Hydrocephalus Caused by Primary Fourth Ventricle Outlet Obstruction: Our Experience and Literature Review

Primary fourth ventricle outlet obstruction (PFVOO) is a rare cause of hydrocephalus with an unclear etiopathogenesis, and thus, consensus regarding the recommended treatment protocol is lacking. This study aims to summarize current knowledge of this condition in the light of our own treatment experience. Retrospective analysis was carried out of all patients treated for noncommunicating tetraventricular hydrocephalus between 2006 and 2019, from which a subgroup of patients with PFVOO was created. A literature review of PFVOO cases was also carried out. A total of 62 patients with PFVOO were discovered, of whom 8 were treated at our institution, representing 3.8% of our patients with noncommunicating hydrocephalus. Patients most commonly presented with headaches, gait disturbance, or symptoms of intracranial hypertension. The mean follow-up duration was 75.4 months among our patients and 29.9 months in the literature. Most patients (54.8%) were treated by endoscopic third ventriculostomy (ETV), with the remainder undergoing suboccipital craniotomy alone (17.7%) or in combination with shunt surgery (9.7%), or endoscopic magendieplasty (12.9%). Treatment failure was noted in 28.6% of ETVs and 9% of craniotomies. No failures were recorded after endoscopic magendieplasty. The risk of treatment failure was found to be significantly higher with ETV compared with other treatment modalities (P < 0.0005). Despite the fact that PFVOO can be defined as an obstructive hydrocephalus, there seems to be a higher risk of ETV failure in such cases. The alternative treatment modalities presented are still recommended. Confirmation of these findings requires a larger multicenter study.

Retrocerebellar Ependymal Cyst Presenting with Obstructive Hydrocephalus in an Infant

AbstractIntracranial ependymal cysts (ECs) are rare benign lesions. They are frequently asymptomatic and arise in the supratentorial regions. Retrocerebellar ECs is a rare location. We present a case of 3-months-old infant who developed obstructive hydrocephalus, bulging fontanel, and macrocephaly secondary to a retrocerebellar EC. Magnetic resonance imaging (MRI) showed a large retrocerebellar cyst that compressed the cerebellum and the brainstem, producing fourth ventricle outlet obstruction and supratentorial hydrocephalus. Microsurgical fenestration of the cyst to the obex of the fourth ventricle and a cystic wall biopsy were performed. The procedure improved supratentorial hydrocephalus, as well as the patient's clinical condition. A histopathological study confirmed the diagnosis of an EC.As far as we know, after a thorough review of the literature, this is the first reported case of retrocerebellar EC. It is a rare cause of hydrocephalus due to outlet obstruction of the fourth ventricle. Treatment of the cause itself was shown to be effective.

Delayed Fourth Ventricle Outlet Obstruction after Fourth Ventricle Tumor Removal Successfully Treated with Endoscopic Third Ventriculostomy in a Pediatric Patient

Introduction: Fourth ventricle outlet obstruction (FVOO) at the level of Magendie’s and Luschka’s foramina is a rare cause of non-communicating hydrocephalus. Case Report: We present a case of a 15-year-old woman successfully operated on a fourth ventricle WHO grade 1 pilocytic astrocytoma developing a delayed FVOO five months after surgery, when the patient experienced progressive headache, nausea and gate disturbances. Magnetic resonance imaging (MRI) study showed a tetra-ventricular hydrocephalus, with enlargement and bulging of both lateral recesses and Luschka’s foramina. An endoscopic third ventriculostomy (ETV) was successfully performed. Postoperative computed tomography (CT) and MRI studies showed a significant improvement of the hydrocephalus. Conclusion: FVOO is a rare cause of hydrocephalus. Posterior fossa and fourth ventricle microsurgical procedures can produce a delayed FVOO leading to an unexpected deterioration of the clinical status of the patient. The ETV is an effective and safe procedure to treat this unusual condition.

ETV in infancy and childhood below 2\xa0years of age for treatment of hydrocephalus

PurposeAge and etiology play a crucial role in success of endoscopic third ventriculostomy (ETV) as a treatment of obstructive hydrocephalus. Outcome is worse in infants, and controversies still exist whether ETV is superior to shunt placement. We retrospectively analyzed 70 patients below 2 years from 4 different centers treated with ETV and assessed success.MethodsChildren < 2 years who received an ETV within 1994–2018 were included. Patients were classified according to age and etiology; < 3, 4–12, and 13–24 months, etiologically; aqueductal stenosis, post-hemorrhagic-hydrocephalus (PHH), tumor-related, fourth ventricle outflow obstruction, with Chiari-type II and following CSF infection. We investigated statistically the predictors for ETV success through computing Kaplan-Meier estimates using patient’s follow-up time and time to ETV failure.ResultsWe collected 70 patients. ETV success rate was 41.4%. The highest rate was in tumor-related hydrocephalus and fourth ventricle outlet obstruction (62.5%, 60%) and the lowest rate was in Chiari-type II and following infection (16.7%, 0%). The below 3 months age group showed relatively lower success rate (33.3%) in comparison to older groups which showed similar results (46.4%, 46.6%). Statistically, a previous VP shunt was a predictor for failure (p value < 0.05).ConclusionFactors suggesting a high possibility of failure were age < 3 months and etiology such as Chiari-type II or following infection. Altered CSF dynamics in patients with PHH and under-developed arachnoid villi may play a role in ETV failure. We do not recommend ETV as first line in children < 3 months of age or in case of Chiari II or following infection.

Third ventriculostomy in fourth ventricle outlet obstruction

A seven years-old boy presented with headache and progressive drowsiness. MRI demonstrated obstruction at the foramen of Magendie and foramina of Luschka. Child underwent an endoscopic third ventriculostomy (ETV). The postoperative course was uneventful. MRI scan showed a marked decrease in the size of the ventricles, showing therefore that cerebrospinal fluid flow through the ventricular system and subarachnoid space was restored de Oliveira RS and Ballestero MFM contributed equally to this manuscript

Investigating cerebral oedema using poroelasticity

Cerebral oedema can be classified as the tangible swelling produced by expansion of the interstitial fluid volume. Hydrocephalus can be succinctly described as the abnormal accumulation of cerebrospinal fluid (CSF) within the brain which ultimately leads to oedema within specific sites of parenchymal tissue. Using hydrocephalus as a test bed, one is able to account for the necessary mechanisms involved in the interaction between oedema formation and cerebral fluid production, transport and drainage. The current state of knowledge about integrative cerebral dynamics and transport phenomena indicates that poroelastic theory may provide a suitable framework to better understand various diseases. In this work, Multiple-Network Poroelastic Theory (MPET) is used to develop a novel spatio-temporal model of fluid regulation and tissue displacement within the various scales of the cerebral environment. The model is applied through two formats, a one-dimensional finite difference – Computational Fluid Dynamics (CFD) coupling framework, as well as a two-dimensional Finite Element Method (FEM) formulation. These are used to investigate the role of endoscopic fourth ventriculostomy in alleviating oedema formation due to fourth ventricle outlet obstruction (1D coupled model) in addition to observing the capability of the FEM template in capturing important characteristics allied to oedema formation, like for instance in the periventricular region (2D model).

Idiopathic fourth ventricle outlet obstruction successfully treated by endoscopic third ventriculostomy: a case report.

IntroductionFourth ventricle outlet obstruction (FVOO) is a rare cause of obstructive hydrocephalus. We describe a case of idiopathic FVOO that was successfully treated with endoscopic third ventriculostomy (ETV).Case reportA 3-year old boy without any remarkable medical history presented with a headache and vomiting. Computed tomography (CT) images, which had incidentally been taken 2 years previously due to a minor head injury, showed no abnormality. Magnetic resonance imaging on admission showed tetra-ventricular hydrocephalus associated with the dilatation of the fourth ventricle outlets, without any obstructive lesions. However, CT ventriculography, involving contrast medium injection through a ventricular catheter, suggested mechanical obstruction of the cerebrospinal fluid (CSF) at the fourth ventricle outlets. Thus, the patient was diagnosed with FVOO and ETV was performed; the hydrocephalus was subsequently resolved. Although hydrocephalus recurred 1 year postoperatively, re-ETV for the highly stenosed fenestration successfully resolved this condition.ConclusionsETV should be considered for FVOO treatment, particularly in idiopathic cases without CSF malabsorption.

Pediatric posterior reversible encephalopathy syndrome presenting with isolated cerebellar edema and obstructive hydrocephalus

In this report, the authors describe the case of a teenage boy who presented with hypertensive emergency, posterior reversible encephalopathy syndrome, and hydrocephalus due to fourth ventricle outlet obstruction. Posterior reversible encephalopathy syndrome is a well-characterized but uncommon syndrome in children that is generally triggered by severe hypertension. The unusual clinical picture of this patient, who had isolated cerebellar edema leading to obstructive hydrocephalus, has been rarely described in children.

Sudden unexpected nocturnal death in Chiari type 1 malformation and potential role of opioid analgesics.

Sir, Our recent article entitled “Sudden unexpected nocturnal death in Chiari type 1 malformation and potential role of opioid analgesics”[5] was criticized by Jonathan and Shlomi.[3] They challenged our opinion without any reference to authenticate their assertions.[3] In our original article, an axial T1-weighted MRI image of the posterior fossa [Figure 1] was replaced by a T2 fluid-attenuated inversion recovery image of a similar view. We do not believe that this oversight could have resulted in their error of mistaking a disproportionately large communicating fourth ventricle (DLCFV) for a “trapped” fourth ventricle.[3] Figure 1 (a) T1-weighted sagittal MRI of the brain demonstrating inferior displacement of the cerebellar tonsils 18 mm below the level of C1 consistent with a Chiari I malformation. Note the relatively mild hydrocephalus and a pear-shaped disproportionately large ... The term “trapped fourth ventricle” is used to describe a dilated fourth ventricle due to obstruction of both its inlet and outlet.[1,5] Shortly before his death, the patient had undergone brain imaging examinations at two different institutions. These studies as well as a postmortem examination excluded the possibility of a trapped fourth ventricle based on the apparent patency of the Sylvius aqueduct.[5] Cystic dilatation of the fourth ventricle is a well-known feature of DLCFV.[1,5] Different mechanisms have been postulated to explain the fourth ventricle dilation and distribution of periventricular edema observed in DLCFV.[1,5] Our experience and published literature indicate that the most likely etiology of DLCFV is increased fragility of the surrounding fourth ventricle tissues to elevated intraventricular pressure, or unequal distribution of intraventricular pressure in tension hydrocephalus such that the intraventricular hypertension primarily affects the ventricle closest to the point where the flow of the cerebrospinal fluid (CSF) is obstructed. In our patient there likely is fourth ventricle outlet obstruction associated with Chiari type 1 malformation (CM1).[1,5] Sleep apnea is a frequent, and sometimes the sole, manifestation of CM1.[4,5] Hydrocephalus, chronic opioid use, and bolus dosing of opioid analgesics are also risk factors for disordered breathing during sleep.[2,4,5] Bolus opiate dosing and sleep apnea associated hypercapnia are known to contribute to intracranial hypertension.[2,5] Therefore in a patient with clinical evidence of high ICP and chronic opioid use, bolus administrations of opioid analgesics can further increase the ICP.[2,5] Increased ICP can give rise to further downward displacement of the brain into the spinal canal and additional compression of vital brain structures. These effects can cause more instability of the cardiopulmonary control centers in the brain stem, resulting in cardiorespiratory arrest with possible sudden “neurogenic” cardiorespiratory death.[5] Therefore, although non–opiate related conditions may have played a role in our patient's clinical deterioration, the patient's death during sleep following administration of opioid analgesics strongly suggests a causal relationship.[5] We agree that some patients diagnosed with CM1 are asymptomatic, but our patient was not asymptomatic; he had a sub-acute clinical course with a fatal outcome.[5] We think that the fatal outcome could have been prevented if his treating physicians were aware of the association between opioids and increased ICP and avoided opioids as much as possible, particularly bolus dosing of opioids before surgery. Therefore, we are ethically obliged to present this report and encourage our colleagues to consider opiates as a potential trigger for the further increase of intracranial hypertension in patients with reduced intracranial compliance.[1,2,5]

Exploring the efficacy of endoscopic ventriculostomy for hydrocephalus treatment via a multicompartmental poroelastic model of CSF transport: a computational perspective.

This study proposes the implementation of a Multiple-Network Poroelastic Theory (MPET) model coupled with finite-volume computational fluid dynamics for the purpose of studying, in detail, the effects of obstructing CSF transport within an anatomically accurate cerebral environment. The MPET representation allows the investigation of fluid transport between CSF, brain parenchyma and cerebral blood, in an integral and comprehensive manner. A key novelty in the model is the amalgamation of anatomically accurate choroid plexuses with their feeding arteries and a simple relationship relaxing the constraint of a unique permeability for the CSF compartment. This was done in order to account for the Aquaporin-4-mediated swelling characteristics. The aim of this varying permeability compartment was to bring to light a feedback mechanism that could counteract the effects of ventricular dilation and subsequent elevations of CSF pressure through the efflux of excess CSF into the blood system. This model is used to demonstrate the impact of aqueductal stenosis and fourth ventricle outlet obstruction (FVOO). The implications of treating such a clinical condition with the aid of endoscopic third (ETV) and endoscopic fourth (EFV) ventriculostomy are considered. We observed peak CSF velocities in the aqueduct of the order of 15.6 cm/s in the healthy case, 45.4 cm/s and 72.8 cm/s for the mild and severe cases respectively. The application of ETV reduced the aqueductal velocity to levels around 16–17 cm/s. Ventricular displacement, CSF pressure, wall shear stress (WSS) and pressure difference between lateral and fourth ventricles (ΔP) increased with applied stenosis, and subsequently dropped to nominal levels with the application of ETV. The greatest reversal of the effects of atresia come by opting for ETV rather than the more complicated procedure of EFV.

Usefulness of Intraoperative Magnetic Resonance Ventriculography During Endoscopic Third Ventriculostomy

Endoscopic third ventriculostomy (ETV) is the preferred method for the treatment of noncommunicating hydrocephalus. The different success rates of ETV indicate the difficulties in predicting the success of this procedure. To show the usefulness of intraoperative ventriculography performed by the low-field 0.15-T magnetic resonance imager Polestar N20 during ETV. The study was conducted in 11 patients with noncommunicating hydrocephalus caused by tumors or cysts of the third ventricle (n = 5), nontumoral stenosis of the sylvian aqueduct (n = 3), and fourth ventricle outlet obstruction (n = 3). Intraoperative magnetic resonance (iMR) ventriculography was performed before and after the ETV. In each case, iMR-ventriculography was a safe procedure and determined the exact site of obstruction of cerebrospinal fluid flow. In all cases, iMR-ventriculography performed after ETV showed with the greatest accuracy the patency of the performed fenestrations, demonstrating in 9 patients good flow of the contrast from the third ventricle to the basal cisterns, restricted flow in 1 patient, and no flow in 1 patient. The results of ventriculography were consistent with the postoperative neurological status of operated-on patients. In 3 patients, the opinion of the surgeons about the patency of endoscopic fenestration, based on intraoperative observation of the third ventricle floor, was inconsistent with the results from iMR-ventriculography. Low-field iMR-ventriculography is a safe procedure that can be successfully applied during ETV to determine the site of obstruction in hydrocephalus and the patency of performed ventricle fenestration.

Regression of cerebellar tonsillar descent and hydrocephalus after endoscopic third ventriculostomy in a patient with a quadrigeminal arachnoid cyst

Background:Posterior fossa arachnoid cysts, including quadrigeminal cistern arachnoid cysts, can occasionally cause compression of the quadrigeminal plate, leading to Sylvian aqueduct stenosis and induction of cerebellar tonsillar descent into the foramen magnum. This, in turn, can result in obstructive hydrocephalus. In such cases, the characteristic of hydrocephalus is generally considered to be hypertensive.Case Description:We present the case of a 28-year-old female complaining of chronic and progressively worsening headaches following the delivery of her first child. Magnetic resonance imaging revealed marked tri-ventriculomegaly, the arachnoid cyst located in the quadrigeminal cistern, and cerebellar tonsillar descent. Ophthalmoscopy revealed bilateral papilledema indicating a long-standing elevation of intracranial pressure. Endoscopic third ventriculostomy (ETV) was performed successfully and resulted in complete recovery from her headaches and papilledema. Postoperative MRI revealed resolution of ventriculomegaly and cerebellar tonsillar descent, suggesting that the fourth ventricle outlet obstruction was associated with the development of the hydrocephalus in this patient.Conclusion:Our case is the first report that a quadrigeminal arachnoid cyst associated with both cerebellar tonsillar descent and hydrocephalus was well treated with ETV. It was indicated that the patient's hydrocephalus and cerebellar tonsillar descent were secondary and synergistic events, caused by the arachnoid cyst located in the quadrigeminal cistern.