Arachnoid Granulations Research Articles

The effect of blood lipids on the comorbidity of multiple large arachnoid granulations

BackgroundCurrently, studies on the formation mechanism for the enlargement of arachnoid granulation (AG) are lacking. The impact of dyslipidemia on the formation of multiple large arachnoid granulations (LAGs) was studied in this research.MethodsThe study included patients diagnosed with cerebral venous sinus stenosis (CVSS) related to LAG. The number of LAGs was assessed via high-resolution black blood magnetic resonance imaging. The relationships between blood lipids and multiple LAGs were explored to evaluate the effects of dyslipidemia on the formation of multiple LAGs.ResultsA total of 163 participants with a diagnosis of LAG were included. The levels of total cholesterol (TC) (P = 0.004) and low-density lipoprotein cholesterol (LDL-c) (P = 0.01) in the multiple LAGs group were greater than those in the non-multiple LAGs group. Multivariate logistic regression analysis revealed that TC (odds ratio (OR), 2.19; 95% confidence interval (CI), 1.26–3.80; P = 0.006) and LDL-c (OR, 2.18; 95% CI, 1.16–4.07; P = 0.02) were independently associated with multiple LAGs.ConclusionsTC and LDL-c are independently related to multiple LAGs, indicating that dyslipidemia may be a potential cause of CVSS. Therefore, monitoring blood lipids may be necessary for patients with LAGs.

Intravenous arachnoid granulation hypertrophy in patients with Parkinson disease

Intravenous arachnoid granulations (AGs) are protrusions of the arachnoid membrane into the venous lumen and function as contributors to the cerebrospinal fluid (CSF) flow circuit. Patients with Parkinson disease (PD) often present with accumulation of alpha synuclein. Previous works have provided evidence for neurofluid circulation dysfunction in neurodegenerative diseases associated with changes in CSF egress, which may have implications regarding AG morphology. The present study aims to investigate group differences in AG volumetrics between healthy and PD participants, as well as relationships between AG characteristics and clinical assessments. Generalized linear models revealed significant increases in AG volumetrics and number in PD compared to healthy controls. Partial Spearman-rank correlation analyses demonstrated significant relationships between AG metrics and motor and cognitive assessments. Finally, AG volumetrics were positively correlated with objective actigraphy measures of sleep dysfunction, but not self-report sleep symptoms.

Hydrocephalus: A Review of Etiology-Driven Treatment Strategies.

Hydrocephalus is a broad term usually understood as cerebrospinal fluid (CSF) accumulation resulting in cerebral ventricular system expansion. The production of CSF is by the choroid plexus in lateral ventricles, flowing between the third and fourth ventricles and eventually to the subarachnoid space. It is critical for proper neuronal function. Hydrocephalus is a neurological pathology linked to high morbidity from neurocognitive and motor impairment. It is classified as either communicating or non-communicating. Communicating hydrocephalus is understood as a deficit at cranial arachnoid villi and granulation absorption sites. However, there has been evidence that extracranial lymphatic vessels in the ethmoid bone region also play a role, as indicated by decreased lymphatic absorption in rat models of hydrocephalus. Treatment typically involves surgical shunt placement or endoscopic third ventriculostomy (ETV) technique with or without choroid plexus cauterization (CPC). These surgical interventions have high failure risks and complications that require re-intervention, further increasing morbidity and mortality risks. To date, there are few nonsurgical treatment strategies, but many have proved limited benefit, and many patients still require surgery. This analysis lays out the typical treatments and explores new, innovative interventions by highlighting the active role of brain parenchymal tissue in the pathogenesis of hydrocephalus.

Widespread haemorrhages in infants post-shunting (WHIPS): clinical features, risk factors and neuroimaging characteristics of a rare and under-recognised phenomenon

PurposeInfants undergoing CSF shunting procedures face a rare complication which we propose to rename “Widespread Haemorrhages in Infants Post-Shunting” (WHIPS) to better capture this unique phenomenon specific to infants undergoing CSF diversion. Our objective is to analyse the risk factors for WHIPS development and provide a detailed neuroradiological description of these haemorrhages.Materials and methodsA radiology information system (RIS) was searched using the search terms “shunt” and/or “catheter” and/or “drain” and/or “ventriculoperitoneal” and/or “VP” between September 2008 to January 2021 for patients < 12 months of age. Clinical data was compiled for each patient meeting the inclusion criteria. Included cases were reviewed by three radiologists for the presence of WHIPS with calculation of the bifrontal ratio and documenting haemorrhage number, morphology, location and lobar distribution.Results51 patients met inclusion criteria, 8 WHIPS patients and 43 controls. There was a statistically significant correlation between a larger post-op head circumference and WHIPS (p = 0.04). WHIPS was associated with post-haemorrhagic hydrocephalus and post-infectious hydrocephalus (p = 0.009). WHIPS were identified in the cortico-subcortical regions, periventricular white matter, and deep white matter. Haemorrhages were either punctate, ovoid or confluent. Haemorrhages ranged from single to innumerable.ConclusionsWHIPS represent a rare and under-recognised complication of CSF shunting unique to the infantile population. We postulate deep and superficial medullary venous haemorrhage as an underlying mechanism related to disordered intracranial hydrodynamics which are exacerbated in the infantile population due to underdeveloped arachnoid granulations and a compliant skull.

Arachnoid granulations in idiopathic intracranial hypertension: Do they have an influence?

The aim of this study was to investigate whether the relative narrowing of the dural venous sinuses by arachnoid granulations (AGs) is more pronounced in patients with idiopathic intracranial hypertension (IIH) compared to healthy controls. IIH is characterized by increased intracranial pressure, which is associated with symptoms such as headache and visual disturbances. The role of cerebral venous drainage obstruction in IIH is the subject of ongoing research. In this retrospective case-control study, 3D contrast-enhanced magnetic resonance images of a cohort of 43 patients with IIH were evaluated for (1) the number of AGs per venous sinus and (2) the diameters of the dural venous sinuses at the site of an AG and at standardized measurement points. In addition, the minimum width of the transverse/sigmoid sinus was measured. All data were compared to the same data from a cohort of 43 control participants. Patients with IIH showed less relative sinus narrowing by AG compared to controls (median: 7%, interquartile range [IQR] 10% vs. 11%, IQR 9% in controls; p = 0.009). In patients with IIH, sinus diameter was larger at the site of an AG (70 ± 25 mm2) compared to its diameter at the standardized measurement point (48 ± 23 mm2; p = 0.010). In the superior sagittal sinus (SSS), patients with IIH had smaller AGs (median: 3 mm2, IQR 2 mm2 vs. 5 mm2, IQR 3 mm2 in controls; p = 0.023) while the respective sinus segment was larger (median: 69 mm2; IQR 21 mm2 vs. 52 mm2, IQR 26 mm2 in controls; p = 0.002). The right transverse sinus was narrower in patients with IIH (41 ± 21 mm vs. 57 ± 20 mm in controls; p < 0.001). In contrast to our hypothesis, patients with IIH showed less pronounced relative sinus narrowing by AG compared to controls, especially within the SSS, where AGs were smaller and the corresponding sinus segment wider. Smaller AGs could result in lower cerebrospinal fluid resorption, favoring the development of IIH. Conversely, the smaller AGs could also be a consequence of IIH due to backpressure in the SSS because of the narrower transverse/sigmoid sinus, which widens the SSS and compresses the AG.

The Effect of Transverse Sinus Stenosis Caused by Arachnoid Granulation on Patients with Venous Pulsatile Tinnitus: A Multiphysics Interaction Simulation Investigation.

This study aimed to investigate the effect of the transverse sinus (TS) stenosis (TSS) position caused by arachnoid granulation on patients with venous pulsatile tinnitus (VPT) and to further identify the types of TSS that are of therapeutic significance for patients. Multiphysics interaction models of six patients with moderate TSS caused by arachnoid granulation and virtual stent placement in TSS were reconstructed, including three patients with TSS located in the middle segment of the TS (group 1) and three patients with TTS in the middle and proximal involvement segment of the TS (group 2). The transient multiphysics interaction simulation method was applied to elucidate the differences in biomechanical and acoustic parameters between the two groups. The results revealed that the blood flow pattern at the TS and sigmoid sinus junction was significantly changed depending on the stenosis position. Preoperative patients had increased blood flow in the TSS region and TSS downstream where the blood flow impacted the vessel wall. In group 1, the postoperative blood flow pattern, average wall pressure, vessel wall vibration, and sound pressure level of the three patients were comparable to the preoperative state. However, the postoperative blood flow velocity decreased in group 2. The postoperative average wall pressure, vessel wall vibration, and sound pressure level of the three patients were significantly improved compared with the preoperative state. Intravascular intervention therapy should be considered for patients with moderate TSS caused by arachnoid granulations in the middle and proximal involvement segment of the TS. TSS might not be considered the cause of VPT symptoms in patients with moderate TSS caused by arachnoid granulation in the middle segment of the TS.

Рathomorphological features of recurrent meningiomas

Background. Meningiomas are common tumors of the central nervous system, most of which are benign. Anaplastic and atypical meningiomas, which together account for 25 % of all meningiomas, have a high recurrence rate even after gross total resection and radiotherapy, which determines a significantly worse prognosis. The mechanisms of recurrence remain poorly understood.Purpose. To assess the significance of arachnoid granulations in the recurrence of meningiomas; to present our own clinical case; to make the review of the literature on this topic.Materials and methods. We searched for publications in the Pubmed, EMBASE, Cohrane Library, and eLibrary databases published between the beginning of database management to February 2023 on the issue of the role of arachnoid granulation in meningioma reccurence. The materials of the desease history and results of histological examination of 71-year-old with intracranial meningioma who were treated in Almazov National Medical Research Center are used in this work.Results. The clinical case of intracranial meningioma surgery is described. Histological examination of the tumor revealed papillary meningioma, grade 3. Tumor growth of meningioma was found in the granulations of the arachnoid. According to the review the clinical case shows the importance of the arachnoid granulations in determining the clinical management for this group of patients.Conclusion. The presented clinical case and analysis of literature data demonstrates the importance of considering the structure of arachnoid granulations in patients with intracranial meningiomas, especially in the recurrent type of the disease. The role of granulations of the arachnoid membrane is currently “forgotten”, but the study of these important structures within the boundaries of the tumor field can provide new information and mechanisms of oncogenesis, malignancy, and recurrence of meningiomas, which may serve as the basis for inclusion in the standards for making a final pathomorphological diagnosis in this groups of patients.

Lumbar Intrathecal Injection in Adult and Neonatal Mice.

This article describes a step-by-step process of lumbar intrathecal injection of Evans blue dye and AAV9-EGFP in adult (2-month-old) and neonatal (postnatal day 10) mice. Intrathecal injection is a clinically translatable technique that has already been extensively applied in humans. In mice, intrathecal injection is considered a challenging procedure that requires a trained and experienced researcher. For both adult and neonatal mice, lumbar intrathecal injection is directed into the L5-L6 intervertebral space. Intrathecally injected material enters the cerebrospinal fluid (CSF) within the intrathecal space from where it can directly access the central nervous system (CNS) parenchyma. Simultaneously, intrathecally injected material exits the CSF with pressure gradient and enters the endoneurial fluid and ultimately the peripheral nerves. While in the CSF, the injectable material also enters the bloodstream and systemic circulation through the arachnoid villi. A successful lumbar intrathecal injection results in adequate biodistribution of the injectable material in the CNS, PNS, and peripheral organs. When correctly applied, this technique is considered as minimally invasive and non-disruptive and can be used for the lumbar delivery of any solute. © 2024 Wiley Periodicals LLC. Basic Protocol 1: C57BL/6 adult and P10 mice lumbar intrathecal injection Basic Protocol 2: Tissue collection and preparation for evaluating Evans blue dye diffusion Basic Protocol 3: Tissue collection and preparation for immunohistochemistry staining Basic Protocol 4: Tissue collection and vector genome copy number analysis.

Biomechanical instability of the brain-CSF interface in hydrocephalus.

Hydrocephalus, characterized by progressive expansion of the CSF-filled ventricles (ventriculomegaly), is the most common reason for brain surgery. 'Communicating' (i.e. non-obstructive) hydrocephalus is classically attributed to a primary derangement in CSF homeostasis, such as choroid plexus-dependent CSF hypersecretion, impaired cilia-mediated CSF flow currents, or decreased CSF reabsorption via the arachnoid granulations or other pathways. Emerging data suggest that abnormal biomechanical properties of the brain parenchyma are an under-appreciated driver of ventriculomegaly in multiple forms of communicating hydrocephalus across the lifespan. We discuss recent evidence from human and animal studies that suggests impaired neurodevelopment in congenital hydrocephalus, neurodegeneration in elderly normal pressure hydrocephalus and, in all age groups, inflammation-related neural injury in post-infectious and post-haemorrhagic hydrocephalus, can result in loss of stiffness and viscoelasticity of the brain parenchyma. Abnormal brain biomechanics create barrier alterations at the brain-CSF interface that pathologically facilitates secondary enlargement of the ventricles, even at normal or low intracranial pressures. This 'brain-centric' paradigm has implications for the diagnosis, treatment and study of hydrocephalus from womb to tomb.

The Spatial Relationship between Spinal Osteoarthritis and CSF Venous Fistulas in Patients with Spontaneous Intracranial Hypotension.

CSF venous fistula leads to spontaneous intracranial hypotension. The exact mechanisms underlying the development of CSF venous fistula remain unclear: Some researchers have postulated that underlying chronic intracranial hypertension may lead to damage to spinal arachnoid granulations, given that many patients with CSF venous fistulas have an elevated body mass index (BMI). However, individuals with higher BMIs are also more prone to spinal degenerative disease, and individuals with CSF venous fistulas also tend to be older. CSF venous fistula tends to occur in the lower thoracic spine, the most frequent location of thoracic degenerative changes. The current study aimed to examine whether CSF venous fistulas are more likely to occur at spinal levels with degenerative changes. Forty-four consecutive patients with CSF venous fistulas localized on dynamic CT myelography were included in analyses. Whole-spine CT was scrutinized for the presence of degenerative changes at each spinal level. The proportion of levels positive for CSF venous fistula containing any degenerative findings was compared to levels without CSF venous fistula using the Fisher exact test. The Pearson correlation coefficient was calculated to explore the association between the burden of degenerative disease and BMI and age and between BMI and opening pressure. Forty-four patients with 49 total CSF venous fistulas were analyzed (5 patients had 2 CSF venous fistulas). Mean patient age was 62.3 (SD, 9.5) years. Forty-seven CSF venous fistulas were located in the thoracic spine; 1, in the cervical spine; and 1, in the lumbar spine. Within the thoracic spine, 39/49 (79.6%) fistulas were located between levels T7-8 and T12-L1. Forty-four of 49 (89.8%) CSF venous fistulas had degenerative changes at the same level. The levels without CSF venous fistulas demonstrated degenerative changes at 694/1007 (68.9%) total levels. CSF venous fistulas were significantly more likely to be present at spinal levels with associated degenerative changes (OR = 4.03; 95% CI, 1.58-10.27; P = .001). Age demonstrated a positive correlation with the overall burden of degenerative disease (correlation coefficient: 0.573, P < .001), whereas BMI did not (correlation coefficient: 0.076, P = .625). There was a statistically significant positive correlation between BMI and opening pressure (correlation coefficient: 0.321, P = .03). Results suggest a potential association between spinal degenerative disease and development of CSF venous fistula.

Neuroophthalmic Manifestations and Management of Cryptococcal Meningitis in HIV-negative Pregnant Woman : A Rare Case

Abstract&#x0D; Introduction : Cryptococcal meningitis (CM) is Cryptococcus infection affecting mostly immunocompromise patients. However, immunocompetent and pregnant woman can also be affected. This condition can cause neuroophthalmic manifestations which may result in permanent vision loss or even death if not managed properly. However, literatures on neuroophthalmic manifestations and management of HIV-negative pregnant woman with CM are very scarce.&#x0D; Case Illustration : We present a rare case of 25 y.o. HIV-negative pregnant woman with neuroophthalmic manifestations associated with CM. The patient was consulted from neurology department with complaints of painless vision loss accompanied by diplopia, severe headache, nausea, and frequent vomitus. Ophthalmological examination showed best corrected visual acuity 20/40 in both eyes, ophthalmoplegia, and grade 4 papilledema. Lumbal puncture result was 89 cmH20. Cerebrospinal fluid (CSF) analysis showed mononuclear cells domination, increased protein, and decreased glucose. Indian ink stain showed Cryptococcus organism. Patient was given intravenous fluconazole, topical nonsteroid anti-inflammatory drug, and therapeutic lumbal punctures which result in clinical improvement.&#x0D; Discussion : CM can cause neuroophthalmic manifestations resulting from increase intracranial pressure (ICP) due to fungal load in arachnoid granulation which obstruct CSF outflow. The manifestations found in this patient were papilledema, ophthalmoplegia, and diplopia due to 6th nerve palsy. The management was multidisciplinary with obstetrics-gynecology and neurology department, focused in pathogen eradication and ICP management to prevent neuroophthalmic sequelae, with considerationof maternal-fetal life saving dilemma.&#x0D; Conclusion : Various neuroophthalmic manifestations can be involved in CM. Prompt and appropriate therapy in a rare case of HIV-negative pregnant woman with CM can decrease both maternal and fetal morbidity and mortality risk.

Spontaneous Cerebrospinal Fluid Leak Presenting as Middle Ear Effusion Caused by Arachnoid Granulations

While middle ear effusion (MEE) is a common ailment in children with Eustachian tube dysfunction, it occurs less frequently in adults. In such cases, a meticulous assessment is essential to discern the underlying cause of MEE. We present an unusual case of spontaneous cerebrospinal fluid (CSF) leak attributed to arachnoid granulation presenting as MEE. A 59-year-old obese female presented with right ear fullness, reduced hearing, and a persistent postnasal drip for 2 years. Audiological testing shows unilateral mild-to-moderate conductive hearing loss in the right ear. Tympanometry assessment revealed a persistent type B pattern in the right ear, indicating persistent unilateral conductive hearing loss. However, despite receiving treatment with nasal decongestants and antihistamines for 2 weeks, no signs of improvement were observed. Subsequently, a right myringotomy and grommet insertion were performed, resulting in the drainage of clear watery fluid that persisted for 2 weeks. A high-resolution computed tomographic scan of the temporal bone revealed the right MEE, bony defect in the right tegmen tympani, and bony irregularities of both tegmen tympani. Magnetic resonance imaging unveiled herniation of the right inferior temporal lobe through the identified tegmen defect. The patient subsequently underwent cortical mastoidectomy, lateral skull base repair, and mastoid obliteration. The histopathological examination of the biopsy taken from the right middle ear tissue revealed fragments of glial tissue with small fragments of trabeculae, which were confirmed by the positivity of the glial fibrillary acidic protein stain. The patient has remained asymptomatic for 10 months following the operation, and her hearing has fully returned to normal. It is advisable to consider CSF effusion as a potential differential diagnosis, particularly among adults aged over 50 years, even in the absence of a history of head trauma, mastoid surgery, or meningitis, when confronted with persistent unilateral MEE.

Assessment of Reversibility of Transverse Venous Sinus Stenosis in Patients With Papilledema.

Bilateral transverse venous sinus stenosis (TVSS) or stenosis of a dominant venous sinus has been found to be very sensitive radiological findings in patients with intracranial hypertension (IH), yet there is still an ongoing debate whether they constitute reversible or permanent phenomena. Thus, the purpose of this study was to investigate the reversibility of TVSS in patients with IH, including conservatively treated patients with signs of IH as defined by the presence of papilledema. This was a retrospective chart review of all patients diagnosed with IH between 2016 and 2022, assessed from 2 tertiary university-affiliated neuro-ophthalmology practices. Inclusion criteria were the presence of papilledema, as quantified by optical coherence tomography, and bilateral TVSS, which is considered typical of IH on neuroimaging. During follow-up, included patients must have had confirmation of papilledema resolution as well as subsequent neuroimaging after conservative treatment or cerebrospinal fluid flow diversion. Patients with dural sinus vein thrombosis or intrinsic stenosis from sinus trabeculations or significant arachnoid granulations were excluded from the study. Either CT venography or MRI/MR venography was reviewed by a fellowship-trained neuroradiologist, and the degree of stenosis was scored through the combined conduit score (CCS), as described by Farb et al. The primary outcome was to assess TVSS changes after resolution or improvement of papilledema. From 435 patients, we identified a subset of 10 who satisfied all inclusion criteria. Our cohort comprised entirely women with a median age of 29.5 years and a median BMI of 32.5 kg/m2. Treatment consisted of acetazolamide in 7 patients, of which 1 had additional topiramate and 2 underwent cerebrospinal fluid flow diversion. Furthermore, 6 patients demonstrated significant weight loss during follow-up. For the primary outcome, 5 of 10 patients exhibited no appreciable TVSS change, and 5 patients demonstrated significant improvement in TVSS, of which 4 received conservative treatment only. Papilledema resolution or improvement was statistically significantly associated with increasing average CCS, TVSS diameter, and grade. We were able to demonstrate that TVSS can be both irreversible and reversible in patients with resolved papilledema. The finding of TVSS reversibility from conservative treatment alone is novel and has important implications to optimize patient care. Future studies should work to identify factors associated with irreversible TVSS for subsequent targeted intervention and prevention.

Deep learning segmentation of peri-sinus structures from structural magnetic resonance imaging: validation and normative ranges across the adult lifespan

BackgroundPeri-sinus structures such as arachnoid granulations (AG) and the parasagittal dural (PSD) space have gained much recent attention as sites of cerebral spinal fluid (CSF) egress and neuroimmune surveillance. Neurofluid circulation dysfunction may manifest as morphological changes in these structures, however, automated quantification of these structures is not possible and rather characterization often requires exogenous contrast agents and manual delineation.MethodsWe propose a deep learning architecture to automatically delineate the peri-sinus space (e.g., PSD and intravenous AG structures) using two cascaded 3D fully convolutional neural networks applied to submillimeter 3D T2-weighted non-contrasted MRI images, which can be routinely acquired on all major MRI scanner vendors. The method was evaluated through comparison with gold-standard manual tracing from a neuroradiologist (n = 80; age range = 11–83 years) and subsequently applied in healthy participants (n = 1,872; age range = 5-100 years), using data from the Human Connectome Project, to provide exemplar metrics across the lifespan. Dice-Sørensen and a generalized linear model was used to assess PSD and AG changes across the human lifespan using quadratic restricted splines, incorporating age and sex as covariates.ResultsFindings demonstrate that the PSD and AG volumes can be segmented using T2-weighted MRI with a Dice-Sørensen coefficient and accuracy of 80.7 and 74.6, respectively. Across the lifespan, we observed that total PSD volume increases with age with a linear interaction of gender and age equal to 0.9 cm3 per year (p < 0.001). Similar trends were observed in the frontal and parietal, but not occipital, PSD. An increase in AG volume was observed in the third to sixth decades of life, with a linear effect of age equal to 0.64 mm3 per year (p < 0.001) for total AG volume and 0.54 mm3 (p < 0.001) for maximum AG volume.ConclusionsA tool that can be applied to quantify PSD and AG volumes from commonly acquired T2-weighted MRI scans is reported and exemplar volumetric ranges of these structures are provided, which should provide an exemplar for studies of neurofluid circulation dysfunction. Software and training data are made freely available online (https://github.com/hettk/spesis).

Contribution of Direct Cerebral Vascular Transport in Brain Substance Clearance.

The accumulation of harmful substances has long been recognized as a likely cause of many neurodegenerative diseases. The two classic brain clearance pathways are cerebrospinal fluid (CSF) and vascular circulation systems. Since the discovery of the glymphatic system, research on the CSF pathway has gained momentum, and impaired CSF clearance has been implicated in virtually all neurodegenerative animal models. However, the contribution of the direct participation of vascular transport across the blood-brain barrier in clearing substances is often ignored in glymphatic papers. Supportive evidence for the direct involvement of parenchymal vasculature in substance clearance is accumulated. First, multiple mechanisms have been proposed for the vascular drainage of exogenous and endogenous substances across the blood-brain barriers. Second, the "traditional" role of arachnoid villi and granulations as the main site for CSF draining into the vasculature system has been questioned. Third, MRI studies using different CSF tracers indicate that parenchymal vasculature directly participates in tracer efflux, consistent with immunohistochemical findings. Here we will review evidence in the literature that supports the direct participation of the parenchymal vascular system in substance clearance, in addition to the CSF clearance pathways.

Endoscopic Third Ventriculostomy: long term results

Objective: Hydrocephalus is a major cause of morbidity in the pediatric population, with potentially severe consequences if left untreated hydrocephalus.&#x0D; Endoscopic third ventriculostomy (ETV) has become the method of choice in the treatment of obstructive hydrocephalus. However, age, ventricular anatomy, and etiology could determine success rates (SR) of ETV. The aim of this study was to identify putative factors that could influence the outcome of ETV in children.&#x0D; Methods: Clinical data of 148 consecutive patients under 18 years of age who underwent 150 consecutive ETVs from January 2000 to January 2019 were reviewed. Data were analyzed with regards to clinical and radiological SR. The actual long-term SR was compared to that predicted by the ETV Success Score (ETVSS) model.&#x0D; Results/Discussion: The study group included 63 males (43%) and 85 females (57%) ranging in age from 11 days to 18 years (mean age of, 6.17 ± 1.02 years; median age 4.5 years) at surgery. Concerning the etiology of hydrocephalus, tumors and aqueductal stenosis (AS) were the most frequently observed, with each occurring in 43 cases (29%), followed by malformations in 31 (21%), cystic lesions in 7 (5%) and other etiologies in 67 patients (16%). The overall SR at the first ETV attempt was 80% (118/148), compared to 74.8% (variance 14.35, 95% CI 69.37–78.22) predicted by the ETVSS. Regarding age, SR was 58% in patients under 6 months of age, 65% in children between 6 months and 1 year, and 86% in children older than 1 year. SR for AS and hydrocephalus associated with posterior fossa tumors were 88 and 90%, respectively. Unsatisfactory results were related to previous intraventricular hemorrhage and infection. The overall complication rate in this series was 13%.&#x0D; The lower SR after ETV in young children may be explained by the poor CSF reabsorption capacity of newborn infants due to immaturity of the arachnoid granulations;&#x0D; Univariate and multivariate analysis showed in our series that both the etiology of hydrocephalus and patient´s age group were relevant factors predicting success.&#x0D; A literature review showed that SR in children under 6 months of age ranged from 32% to 45%, and in children older than one year it ranged from 56% to 71%. A few studies have analyzed the postoperative course and SR after a period of 3 years.&#x0D; Conclusion: ETV is safe and effective in children. In this series, the age of the patient and etiology of hydrocephalus were related to SR. Also, the ETVSS was accurate to predict outcome. Intraventricular hemorrhage, previous CNS infection, myelomeningocele, prematurity and recurrent shunt revisions have been associated with high failure rates of ETV in all age groups, particularly in infants under 6 months of age. In a long-term follow-up, surgical experience was statistically significant in reducing complications.

Circular Configuration of Torcular Herophili Presenting as Childhood Headache: 2D Computational Fluid Dynamic Analysis with a Proposed Mechanism.

This case report presents a rare anatomical variant of the torcular Herophili, characterized by a circular configuration and the absence of the left transverse sinus. A 12-year-old child presented with intermittent holocranial headaches, and imaging revealed the circular torcular Herophili along with mild ventricular enlargement. The straight sinus drained into the left side of the circular torcular Herophili. Following lumbar puncture and cerebrospinal fluid (CSF) drainage, the child experienced symptom improvement. During a 6-month follow-up, the patient remained asymptomatic, without further headaches or academic disruptions. Similar to a previously reported case, the circular torcular Herophili with unilateral absent transverse sinus may be associated with impaired CSF absorption due to altered blood flow through abnormal venous anatomy. We performed two-dimensional computational fluid dynamic analysis of simulated flow through a synthetic model and showed that this circular configuration is associated with venous stasis. The venous stasis in the sinus may impair CSF absorption through the arachnoid granulations causing hydrocephalus and explaining the headache. Close monitoring and follow-up are recommended for patients with this variant. Further investigation is needed to better understand the clinical implications and underlying mechanisms of such torcular Herophili variations.

Addressing hydrocephalus in Africa: Challenges and way forward.

Hydrocephalus occurs when the cerebrospinal fluid (CSF) accumulates in the cerebral ventricles. This is due to either obstruction in the CSF flow, decreasing its absorption by the arachnoid villus to the Dural venous sinuses, or increasing production of the CSF. The most disproportionately and severely affected by the disease consequences are African children. This is because of the high incidence of postinfectious hydrocephalus and spinal dysraphism compared with other world children. The health care system in Africa has access to 488 neurosurgeons which represents less than 1% of the global neurosurgeons, thus pediatric hydrocephalus is considered an emerging public health problem in Africa because of the difficulty of the patient's access to proper care. Numerous studies conducted in Africa have revealed a significant imbalance in the distribution of neurosurgical resources across the continent. Specifically, South Africa and North Africa collectively account for 86% of the total practicing neurosurgeons, indicating a pronounced concentration of these specialized medical professionals in these regions. Having an abundance of case studies regarding hydrocephalus is vital to increase our awareness and understanding. Hydrocephalus should gain more priority by current policymakers as an important health concern. This may be achieved by proper resource allocation to ensure better quality means of diagnosis, intervention, and rehabilitation.

Update on meningioma: Clinical-radiological and radio-pathological correlation

Meningiomas are tumors that originate in the arachnoid villi and are the most common non-glial neoplasm in the central nervous system. The clinical manifestations associated with meningioma depend, fundamentally, on its location. The location in the cerebral convexity is the most frequent, especially in the frontal lobes, manifesting with headache, motor disturbances, seizures and even neurocognitive disorders. There are 15 histologic subtypes of meningioma and three histologic grades. Within these, grades two and three have a worse prognosis and a higher rate of recurrence, as well as a radiological behavior that is generally more aggressive. Although there are some imaging features that can suggest a specific subtype, the definitive diagnosis will always require histological/molecular confirmation.

Evaluation of Arachnoid Granulations in Cranial Dural Sinuses with Contrast-Enhanced 3-Dimensional T1-Weighted Magnetic Resonance Imaging.

Several studies in the literature have used contrast-enhanced magnetic resonance imaging to investigate arachnoid granulations protruding into the cranial dural sinuses. The current study aimed to investigate the protrusion of arachnoid granulations into the superior sagittal sinus, transverse sinus, straight sinus, and confluence of sinuses and determine the frequency of brain herniation into giant arachnoid granulations using contrast-enhanced 3-dimensional T1-weighted magnetic resonance imaging. Images of 550 patients with intra-sinus arachnoid granulations who underwent contrast-enhanced 3-dimensional T1-weighted thin-slice magnetic resonance imaging were retrospectively re-evaluated. Only 300 patients with at least 1 intra-sinus arachnoid granulation were included in the study. The protrusion of arachnoid granulations into superior sagittal sinus, transverse sinus, straight sinus, and confluence of sinuses was investigated. In addition, large arachnoid granulations and brain herniations into arachnoid granulations were also noted. A total of 889 focal filling defects of arachnoid granulations, at least 1 in the dural sinus, were detected. Of the filling defects of arachnoid granulations, 183 were in the right transverse sinus, 222 in the left transverse sinus, 265 in superior sagittal sinus, 185 in straight sinus, and 34 in confluence of sinuses. Brain herniation into arachnoid granulations was detected in 8 (2.7%) of the patients included in the study. All the filling defects detected in the dural sinuses on post-contrast 3-dimensional T1-weighted images were isointense with cerebrospinal fluid and had round, oval, or lobulated contours. A positive weak correla- tion was found between patient age and the size and number of arachnoid granulations (r = 0.181, P < .01 and r=0.207, P < .001, respectively). It was observed that the size and number of arachnoid granulations increased as the age of the patients increased. The distribution, shape, number, and size of intra-sinus arachnoid granulations can vary considerably. Brain herniation into arachnoid granulation can also be seen. Three-dimensional cranial magnetic resonance imaging sequences can be safely used in the evaluation of arachnoid granulations.