Fourth Ventricle Research Articles

Effects of systemic oxytocin and beta-3 receptor agonist (CL 316243) treatment on body weight and adiposity in male diet-induced obese rats.

Previous studies have implicated hindbrain oxytocin (OT) receptors in the control of food intake and brown adipose tissue (BAT) thermogenesis. We recently demonstrated that hindbrain [fourth ventricle (4V)] administration of oxytocin (OT) could be used as an adjunct to drugs that directly target beta-3 adrenergic receptors (β3-AR) to elicit weight loss in diet-induced obese (DIO) rodents. What remains unclear is whether systemic OT can be used as an adjunct with the β3-AR agonist, CL 316243, to increase BAT thermogenesis and elicit weight loss in DIO rats. We hypothesized that systemic OT and β3-AR agonist (CL 316243) treatment would produce an additive effect to reduce body weight and adiposity in DIO rats by decreasing food intake and stimulating BAT thermogenesis. To test this hypothesis, we determined the effects of systemic (subcutaneous) infusions of OT (50 nmol/day) or vehicle (VEH) when combined with daily systemic (intraperitoneal) injections of CL 316243 (0.5 mg/kg) or VEH on body weight, adiposity, food intake and brown adipose tissue temperature (T IBAT ). OT and CL 316243 monotherapy decreased body weight by 8.0±0.9% ( P <0.05) and 8.6±0.6% ( P <0.05), respectively, but OT in combination with CL 316243 produced more substantial weight loss (14.9±1.0%; P <0.05) compared to either treatment alone. These effects were associated with decreased adiposity, energy intake and elevated T IBAT during the treatment period. The findings from the current study suggest that the effects of systemic OT and CL 316243 to elicit weight loss are additive and appear to be driven primarily by OT-elicited changes in food intake and CL 316243-elicited increases in BAT thermogenesis.

Fourth ventricular roof angle does not predict surgical outcome in paediatric patients with Chiari I malformation.

Pre-operative fourth ventricle roof angle (FVRA) has recently been highlighted as a novel radiographic predictor of clinical severity in Chiari type-I malformation (CM-I) as reported by Seaman et al. (J Neurosurg Pediatr 25:1-8, 2021). This has led to suggestions that FVRA could be included in algorithms to determine indications for surgery. We aimed to test the accuracy of FVRA as a predictor of clinical severity and its effect on post-operative outcome in a large retrospective cohort of paediatric patients who underwent decompression for CM-I. Patients undergoing craniocervical decompression for CM-I at the Queensland Children's Hospital and Mater Hospital, Brisbane, between 2006 and 2018 were included. Data was collected from 66 patients aged 0-18years. Post-operative outcome was assessed by calculating Chicago Chiari Outcomes Score (CCOS) at follow-up. The FVRA was taken from a mid-sagittal T1-weighted MRI as previously described (Seaman et al. in J Neurosurg Pediatr 25:1-8, 2021). The angle is subtended between superior and inferior medullary velum. Whilst results from Seaman et al. demonstrated a strong correlation between a FVRA > 65° and symptomatic CM-I, this did not translate to our dataset (p = 0.61). Additionally, pre-operative FVRA is not useful as a predictive tool for post-surgical outcome as assessed by CCOS (p = 0.50), and post-operative reduction in FVRA did not correlate with improved outcomes (p = 0.81). We did note significantly worse outcomes in patients presenting with pre-operative brainstem dysfunction (p = 0.03). Paediatric CM-I is a challenging cohort to manage, often due to young age and a lack of language skills. There is a heavy reliance on radiological findings. Whilst FVRA has previously been reported to be of value as a determinant of clinical severity in adult and paediatric patients, we find that this measurement is of dubious value in our retrospective cohort.

The Ratio of Baseline Ventricle Volume to Total Brain Volume Predicts Postoperative Ventriculo-Peritoneal Shunt Dependency after Sporadic Vestibular Schwannoma Surgery.

Background/Objectives: Obstructive hydrocephalus associated with vestibular schwannoma (VS) is the most common in giant VS. Despite tumor removal, some patients may require ongoing ventriculo-peritoneal (VP) surgery. This investigation explores the factors contributing to the requirement for VP surgery following VS surgery in instances of persistent hydrocephalus (HCP). Methods: Volumetric MRI analyses of pre- and postoperative tumor volumes, cerebellum, cerebrum, ventricle system, fourth ventricle, brainstem, and peritumoral edema were conducted using Brainlab Smartbrush and 3D Slicer. The total brain volume was defined as the sum of the cerebrum, cerebellum, and brainstem. ROC analyses were performed to identify the optimum cut-off values of the volumetric data. Results: Permanent cerebrospinal fluid (CSF) diversion after surgery was indicated in 12 patients (12/71; 16.9%). The ratio of baseline volume fraction of brain ventricles to total brain ventricle volume (VTB ratio) was found to predict postoperative VP shunt dependency. The AUC was 0.71 (95% CI: 0.51-0.91), and the optimum threshold value (</≥0.449) yielded a sensitivity and specificity of 67% and 81%, respectively. Multivariable logistic regression analyses of imaging data (pre- and postoperative VS volume, VTB ratio, and extent of resection (%) (EoR)) and patient-specific factors revealed that an increased VTB ratio (≥0.049, OR: 6.2, 95% CI: 1.0-38.0, p = 0.047) and an EoR < 96.4% (OR: 9.1, 95% CI: 1.2-69.3, p = 0.032) were independently associated with postoperative VP shunt dependency. Conclusions: Primary tumor removal remains the best treatment to reduce the risk of postoperative persistent hydrocephalus. However, patients with an increased preoperative VTB ratio are prone to needing postoperative VP shunt surgery and may benefit from perioperative EVD placement.

Dandy-Walker malformations with other complex congenital deformities associated with scoliosis: a case series.

Dandy-Walker malformations (DWM) is a rare condition with an estimated prevalence of 1 in 30 000 cases. Although DWM often complicates scoliosis, its prevalence and the time of onset are unknown because only a few reports have described the association between scoliosis and DWM. This case series describes spinal deformity associated with DWM. The clinical records and spinal radiographs of 23 consecutive patients with DWM at a single centre were reviewed. DWM was clinically diagnosed if patients met the following three conditions: (1) posterior fossa enlargement, (2) cerebellar hypoplasia and (3) cystic dilation of the fourth ventricle on MRI. Radiological assessment records for the presence, prevalence and time of onset of DWM were studied. Twelve of 23 patients (52%) demonstrated a scoliotic deformity, with 3 (13%) having severe deformities exceeding 60°. The average age at diagnosis was 3.6 ± 2.9 years (range: 0.7-9.7) and at radiographic examination during the final follow-up was 8.7 years (range 1.0-22.0). Only two patients were skeletally mature. The coronal angular deformity at the final follow-up was 34.2 ± 32.3° (range: 10.1-125.1°). One patient with moderate deformity >25° died before bracing. In addition, of three patients with severe deformities, only one had undergone posterior spinal fusion. The prevalence of scoliosis in DWM was 52%, and all patients who developed scoliosis reported early-onset scoliosis under 10 years of age. Early diagnosis and screening of spine deformity are required for patients with DWM to prevent disease progression. Evidence level: 4.

Sympathetic innervation of interscapular brown adipose tissue is not a predominant mediator of OT-elicited reductions of body weight gain and adiposity in male diet-induced obese rats.

Recent studies indicate that central administration of oxytocin (OT) reduces body weight (BW) in high fat diet-induced obese (DIO) rodents by reducing energy intake and increasing energy expenditure (EE). Previous studies in our lab have shown that administration of OT into the fourth ventricle (4V; hindbrain) elicits weight loss and stimulates interscapular brown adipose tissue temperature (TIBAT) in DIO rats. We hypothesized that OT-elicited stimulation of sympathetic nervous system (SNS) activation of IBAT contributes to its ability to activate BAT and reduce BW in DIO rats. To test this, we determined the effect of disrupting SNS activation of IBAT on OT-elicited stimulation of TIBAT and reduction of BW in DIO rats. We first confirmed that bilateral surgical SNS denervation to IBAT was successful based on having achieved ≥ 60% reduction in IBAT norepinephrine (NE) content from DIO rats. NE content was selectively reduced in IBAT by 94.7 ± 2.7, 96.8 ± 1.8 and 85.9 ± 6.1% (P<0.05) at 1, 6 and 7-weeks post-denervation, respectively, and was unchanged in liver or inguinal white adipose tissue. We then measured the impact of bilateral surgical SNS denervation to IBAT on the ability of acute 4V OT (1, 5 μg) to stimulate TIBAT in DIO rats. We found that the high dose of 4V OT (5 μg) stimulated TIBAT similarly between sham and denervated rats (P=NS) and that the effects of 4V OT to stimulate TIBAT did not require beta-3 adrenergic receptor signaling. We subsequently measured the effect of bilateral surgical denervation of IBAT on the effect of chronic 4V OT (16 nmol/day) or vehicle infusion to reduce BW, adiposity and energy intake in DIO rats. Chronic 4V OT reduced BW gain by -7.2 ± 9.6 g and -14.1 ± 8.8 g in sham and denervated rats (P<0.05 vs vehicle treatment), respectively, and this effect was similar between groups (P=NS). These effects were associated with reductions in adiposity and energy intake (P<0.05). Collectively, these findings support the hypothesis that sympathetic innervation of IBAT is not required for central OT to increase BAT thermogenesis and reduce BW gain and adiposity in male DIO rats.

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.

Obsessive–compulsive Disorder in a Young Girl with Subependymal Heterotopia, Aqueductal Stenosis, and Mega Cisterna Magna Along with Left-sided Mild Cerebellar Hypoplasia

Gray matter heterotopia (GMH) is a rare disorder in the general population, but recent attention to its psychiatric aspects encouraged us to introduce a patient with a form of gray matter heterotopia, who suffers from the anatomical abnormalities with a variety of psychiatric disorders. During the late teenage years or early adulthood, a wide variety of neuropsychiatric symptoms may be present, which can lead to diagnostic difficulties. The Dandy–Walker variant is a milder form of the Dandy–Walker complex and is characterized by normal-sized posterior fossa, mild vermian hypoplasia, and a cystic lesion that communicates with the fourth ventricle. This syndrome has been described in association with schizophrenia, obsessive–compulsive disorder (OCD), manic episode, psychosis, and recurrent catatonia. Presenting a case report of an 11-year-old girl with OCD who was accidentally detected with the presence of GMH along with aqueductal stenosis, mega cisterna magna, and left-sided mild cerebellar hypoplasia.

The cerebrospinal fluid (CSF)-contacting raphe nucleus (CsfR) in mice

A unique nucleus, the cerebrospinal fluid-contacting nucleus (CsfR), has been identified in the brain parenchyma. This nucleus features neurons with somas located within the parenchyma and processes extending into the cerebrospinal fluid (CSF). This anatomical configuration suggests that the CsfR may serve as a crucial interface between the nervous and body fluid regulatory systems, potentially playing a significant role in overall physiological modulation. Despite its importance, the precise biological significance of the CsfR remains to be fully elucidated. Previous research has characterized the CsfR, providing detailed information on its position, neighboring structures, neuron distribution, and 3D reconstruction in both rats and non-human primates, with stereotaxic coordinates specifically provided for the rat model. Given the relevance of mice as a model organism, especially the C57BL/6J strain, this study aims to explore the existence and morphology of the CsfR in mice. Our findings confirm the presence of the CsfR, consistently located in the ventral gray area of the lower part of the aqueduct and the upper part of the fourth ventricle floor. It is bilaterally symmetrical and heart-shaped in the coronal plane, which differs slightly from the Y-shape observed in coronal sections of rats. This study provides significant references for researchers investigating this specialized nucleus.

CSF dynamics throughout the ventricular system using 4D flow MRI: associations to arterial pulsatility, ventricular volumes, and age

BackgroundCerebrospinal fluid (CSF) dynamics are increasingly studied in aging and neurological disorders. Models of CSF-mediated waste clearance suggest that altered CSF dynamics could play a role in the accumulation of toxic waste in the CNS, with implications for Alzheimer’s disease and other proteinopathies. Therefore, approaches that enable quantitative and volumetric assessment of CSF flow velocities could be of value. In this study we demonstrate the feasibility of 4D flow MRI for simultaneous assessment of CSF dynamics throughout the ventricular system, and evaluate associations to arterial pulsatility, ventricular volumes, and age.MethodsIn a cognitively unimpaired cohort (N = 43; age 41–83 years), cardiac-resolved 4D flow MRI CSF velocities were obtained in the lateral ventricles (LV), foramens of Monro, third and fourth ventricles (V3 and V4), the cerebral aqueduct (CA) and the spinal canal (SC), using a velocity encoding (venc) of 5 cm/s. Cerebral blood flow pulsatility was also assessed with 4D flow (venc = 80 cm/s), and CSF volumes were obtained from T1- and T2-weighted MRI. Multiple linear regression was used to assess effects of age, ventricular volumes, and arterial pulsatility on CSF velocities.ResultsCardiac-driven CSF dynamics were observed in all CSF spaces, with region-averaged velocity range and root-mean-square (RMS) velocity encompassing from very low in the LVs (RMS 0.25 ± 0.08; range 0.85 ± 0.28 mm/s) to relatively high in the CA (RMS 6.29 ± 2.87; range 18.6 ± 15.2 mm/s). In the regression models, CSF velocity was significantly related to age in 5/6 regions, to CSF space volume in 2/3 regions, and to arterial pulsatility in 3/6 regions. Group-averaged waveforms indicated distinct CSF flow propagation delays throughout CSF spaces, particularly between the SC and LVs.ConclusionsOur findings show that 4D flow MRI enables assessment of CSF dynamics throughout the ventricular system, and captures independent effects of age, CSF space morphology, and arterial pulsatility on CSF motion.

Joubert syndrome: a rare cause of hypotonia with developmental delay

Joubert syndrome is a rare autosomal recessive disorder. It is characterized by congenital ataxia, hypotonia, developmental delay, and at least one of the following features: neonatal respiratory disturbances and abnormal eye movements; including nystagmus and oculomotor apraxia. Molar tooth appearance is an essential finding for the diagnosis of Joubert syndrome. Here we presented a case of an 18-month-old male who presented with developmental delay and marked hypotonia. The main purposes of the case report were to highlight the benefit of a multidisciplinary rehabilitation team approach and describe the clinical features associated with Joubert syndrome. Brain magnetic resonance imaging showed a thick, elongated, and abnormally oriented superior cerebellar peduncle showing a molar tooth appearance with elongated bat-wing-shaped 4th ventricle and hypoplasia of the vermis suggestive of JS. Hypotonia during infancy and developmental delay with or without learning disability, associated with abnormal breathing patterns and abnormal eye movements (nystagmus) along with the radiological presence of a molar tooth sign on the brain MRI is an essential component to confirm the diagnosis.

Metachronous intracranial meningiomas without dural attachment in a child - Rare case report and review of literature.

Meningiomas in children are rare, constituting less than 5% of all paediatric brain tumours and less than 2% of all meningiomas. Multiple meningiomas (synchronous or metachronous) are even more uncommon, typically occurring due to radiation exposure or in patients with phacomatoses like Neurofibromatosis II. This report presents the case of a child with metachronous meningiomas without dural attachment in unusual locations, along with their management. This report aims to describe a rare paediatric case of metachronous meningiomas without dural attachment, detailing their presentation, treatment, and outcomes. A 2-year-old female presented with headaches, irritability, and excessive crying for one year. A CT scan revealed a mass in the fourth ventricle, causing obstruction, which was surgically decompressed. The biopsy confirmed a clear cell meningioma, WHO grade II. A follow-up MRI identified a new lesion in the suprasellar area six months later, for which she underwent right pterional craniotomy and gross total resection, which turned out to be a clear cell meningioma, WHO grade II. The patient recovered well and remained asymptomatic, with no recurrence on MRI at one-year follow-up. This case highlights the unusual presentation of metachronous clear cell meningiomas without dural attachment in a young child. Surgical excision resulted in a favourable outcome, though long-term follow-up is essential due to the high propensity for recurrence.

The tonsillouvular fissure approach to exophytic cavernous malformation in the lateral recess of the fourth ventricle: 2-dimensional operative video

Cavernous malformations surrounding the fourth ventricle are challenging lesions to access and treat surgically owing to the complexity and eloquence of adjacent neural tissue [1] Long-standing practice included tissue transgression through the overlying cerebellar cortical surface of the hemisphere or vermis [1–3]. Using natural corridors such as tonsillobiventral fissure, cerebellomedullary fissure, and tonsillouvular fissure (TUF) offers elegant access to the fourth ventricle, avoiding traversing of neural tissue [4–7].A 32-year-old male presented with headache, nausea, vomiting, double vision, and vertigo. Neuroimaging demonstrated a 17-mm diameter cavernous malformation protruding into the left lateral recess of the fourth ventricle. The patient consented for the procedure and underwent a middline suboccipital craniotomy in a prone position. TUF approach was performed by dissecting the arachnoid to the depth of the fissure, and after identifying the tonsillomedullary segment of the posterior inferior cerebellar artery, minimal white matter transgression was used to reach cavernous malformation. Complete removal of the lesion was achieved and confirmed on postoperative imaging. The postoperative course was uneventful.TUF approach with manipulation by ipsilateral and contralateral retraction of tonsills allows the widening of the surgical corridor and better exposure of lesions of the lateral recess of the fourth ventricle [1]. TUF approach is a valuable alternative to transvermian and transcerebellar approaches that minimize the division of neural tissue [6]. To the best of our knowledge this is the first case describing the TUF approach to exophytic cavernoma presenting in the lateral recess of the fourth ventricle.Under our institutional ethical review board regulations, approval was not necessary.

Delayed recovery of consciousness from anesthesia due to exacerbation of hydrocephalus caused by a ventriculoperitoneal shunt malfunction during general anesthesia in the prone position: a case report

BackgroundDysfunction of ventriculoperitoneal (VP) shunts can lead to decreased levels of consciousness. We report a case of delayed emergence from anesthesia due to the malfunction of a VP shunt during neurosurgery in the prone position.Case presentationA 75-year-old male with a history of VP shunt for a fourth ventricle obstruction underwent cerebral vascular anastomosis in the prone position. His preoperative level of consciousness was clear. The surgery under general anesthesia was completed without any particular issues. After discontinuation of anesthesia, the patient did not awaken for over an hour. Postoperative CT revealed exacerbated hydrocephalus, likely from VP shunt occlusion. After pumping the reservoir of the VP shunt, the patient regained consciousness. He was extubated and discharged from ICU on the second postoperative day with no neurological issues.ConclusionFor surgical patients with a VP shunt, anesthesia management must consider the risk of shunt malfunction due to patient positioning.

The hypervirulent Group B Streptococcus HvgA adhesin promotes central nervous system invasion through transcellular crossing of the choroid plexus

BackgroundGroup B Streptococcus (GBS) is the leading cause of neonatal meningitis responsible for a substantial cause of death and disability worldwide. The vast majority of GBS neonatal meningitis cases are due to the CC17 hypervirulent clone. However, the cellular and molecular pathways involved in brain invasion by GBS CC17 isolates remain largely elusive. Here, we studied the specific interaction of the CC17 clone with the choroid plexus, the main component of the blood-cerebrospinal fluid (CSF) barrier.MethodsThe interaction of GBS CC17 or non-CC17 strains with choroid plexus cells was studied using an in vivo mouse model of meningitis and in vitro models of primary and transformed rodent choroid plexus epithelial cells (CPEC and Z310). In vivo interaction of GBS with the choroid plexus was assessed by microscopy. Bacterial invasion and cell barrier penetration were examined in vitro, as well as chemokines and cytokines in response to infection.ResultsGBS CC17 was found associated with the choroid plexus of the lateral, 3rd and 4th ventricles. Infection of choroid plexus epithelial cells revealed an efficient internalization of the bacteria into the cells with GBS CC17 displaying a greater ability to invade these cells than a non-CC17 strain. Internalization of the GBS CC17 strain involved the CC17-specific HvgA adhesin and occurred via a clathrin-dependent mechanism leading to transcellular transcytosis across the choroid plexus epithelial monolayer. CPEC infection resulted in the secretion of several chemokines, including CCL2, CCL3, CCL20, CX3CL1, and the matrix metalloproteinase MMP3, as well as immune cell infiltration.ConclusionOur findings reveal a GBS strain-specific ability to infect the blood-CSF barrier, which appears to be an important site of bacterial entry and an active site of immune cell trafficking in response to infection.

Role of surgery in the treatment of pediatric low-grade glioma with various degrees of brain stem involvement

ObjectivePosterior fossa pediatric low-grade glioma involving the brainstem and cerebellar peduncles (BS-pLGG) are a subgroup with higher risks at surgery. We retrospectively analyzed the role of surgery in the interdisciplinary armamentarium of treatment options in our institutional series of BS-pLGG with various degrees of brainstem involvement.Material and methodsWe analyzed data of 52 children with BS-pLGG after surgical intervention for clinical/molecular characteristics, neurological outcome, factors influencing recurrence/progression pattern, and tumor volumetric analysis of exclusively surgically treated patients to calculate tumor growth velocity (TGV). Tumors were stratified according to primary tumor origin in four groups: (1) cerebellar peduncle, (2) 4th ventricle, (3) pons, (4) medulla oblongata.ResultsThe mean FU was 6.44 years. Overall survival was 98%. The mean PFS was 34.07 months. Two patients had biopsies only. Fifty-two percent of patients underwent remission or remained in stable disease (SD) after initial surgery. Patients with progression underwent further 23 resections, 15 chemotherapies, 4 targeted treatments, and 2 proton radiations. TGV decreased after the 2nd surgery compared to TGV after the 1st surgery (p < 0.05). The resection rates were significantly higher in Groups 1 and 2 and lowest in medulla oblongata tumors (Group 4) (p < 0.05). More extended resections were achieved in tumors with KIAA1549::BRAF fusion (p = 0.021), which mostly occurred in favorable locations (Groups 1 and 2). Thirty-one patients showed postoperatively new neurological deficits. A total of 27/31 improved within 12 months. At the end of FU, 6% had moderate deficits, 52% had mild deficits not affecting activities, and 36% had none. Fifty percent of patients were free of disease or showed remission, 38% were in SD, and 10% showed progression.ConclusionThe first surgical intervention in BS-pLGG can control disease alone in overall 50% of cases, with rates differing greatly according to location (Groups 1 > 2 > 3 > 4), with acceptable low morbidity. The second look surgery is warranted except in medullary tumors. With multimodality treatments almost 90% of patients can obtain remission or stable disease after > 5 years of follow-up. An integrated multimodal and multidisciplinary approach aiming at minimal safe residual disease, combining surgery, chemo-, targeted therapy, and, as an exception, radiation therapy, is mandatory.

Predictors of Hydrocephalus Risk After Stereotactic Radiosurgery for Vestibular Schwannomas: Utility of the Evans Index.

Hydrocephalus after Gamma Knife® stereotactic radiosurgery (SRS) for vestibular schwannomas is a rare but manageable occurrence. Most series report post-SRS communicating hydrocephalus in about 1% of patients, thought to be related to a release of proteinaceous substances into the cerebrospinal fluid. While larger tumor size and older patient age have been associated with post-SRS hydrocephalus, the influence of baseline ventricular anatomy on hydrocephalus risk remains poorly defined. A single-institution retrospective cohort study examining patients who developed symptomatic communicating hydrocephalus after undergoing Gamma Knife® SRS for unilateral vestibular schwannomas from 2011 to 2021 was performed. Patients with prior hydrocephalus and cerebrospinal fluid diversion or prior surgical resection were excluded. Baseline tumor volume, third ventricle width, and Evans Index (EI)-maximum width of the frontal horns of the lateral ventricles/maximum internal diameter of the skull-were measured on axial postcontrast T1-weighted magnetic resonance imaging. A total of 378 patients met the inclusion criteria; 14 patients (3.7%) developed symptomatic communicating hydrocephalus and 10 patients (2.6%) underwent shunt placement and 4 patients (1.1%) were observed with milder symptoms. The median age of patients who developed hydrocephalus was 69 years (IQR, 67-72) and for patients younger than age 65 years, the risk was 1%. For tumor volumes <1 cm3, the risk of requiring shunting was 1.2%. The odds of developing symptomatic hydrocephalus were 5.0 and 7.7 times higher in association with a baseline EI > 0.28 (P = .024) and tumor volume >3 cm3 (P = .007), respectively, in multivariate analysis. Fourth ventricle distortion on pre-SRS imaging was significantly associated with hydrocephalus incidence (P < .001). Patients with vestibular schwannoma with higher baseline EI, larger tumor volumes, and fourth ventricle deformation are at increased odds of developing post-SRS hydrocephalus. These patients should be counseled regarding risk of hydrocephalus and carefully monitored after SRS.

An Unusual Case of CNS Tuberculoma in a 19-Year-Old Man

Background: Tuberculosis (TB) is ranked as one of the top 10 causes of death. Mycobacterium tuberculosis (M. TB) infection, the causative organism for TB affects approximately a quarter of the global population placing a burden on the healthcare system. Central nervous system tuberculosis (CNS TB) is seen in 5 to 10% of extrapulmonary TB cases and has the highest mortality. CNS tuberculoma is one of its manifestation. Clinical presentation of CNS tuberculoma depends on its location within the CNS and commonly include headache, seizures, and focal neurological deficits, due to the presence of a space occupying lesion, although patients can be asymptomatic. We report the case of a 19yr old man who had an unusual presentation of CNS tuberculoma, highlighting its clinical presentation, diagnosis and treatment. Case Presentation: Index patient is a 19-year-old male college student who resides in a city. He presented with 15 days history of fever, headache, vomiting, vertigo, ataxia, and inability to concentrate. He received antimalarial, anti typhoid and body booster medications but had no improvement and had a history of weight loss despite no dietary change. He had never been diagnosed with TB and had all his childhood vaccinations given. Plain Magnetic Resonance Imaging (MRI) brain scan done revealed a posterior fossa mass lesion with perilesional edema. Futher, a contrast MRI brain scan showed multiple ring-enhancing conglomerates of lesion around the tentorium on the posterior fossa with intense contrast enhancement. The largest of this mass measured 4.5 cm x 2.5 cm x 2.5 cm in the right superior cerebellum compressing the 4th ventricle and with effacement of the cerebellopontine angle. Lastly, an MRI spectrometry revealed elevated lipid lactate peak. His chest x-ray was unremarkable. Other blood parameters were essentially within range with the exception of Erythrocyte ESR and mantoux test. He received antitubercular drug (Isoniazid, Rifampin, Pyrazinamide, Ethambutol, Levoflox and Streptomycin) for 18th months with complete remission. Conclusion: CNS tuberculomas are tuberculous masses that can be located anywhere from the brain to spinal cord. Advanced diagnostic modalities may guide clinicians towards making it's diagnosis. Treatment maybe medical (use of antitubercular drugs) or surgical excision with medical therapy being first choice. While the index patient had no obvious risk factors for his disease, his BCG vaccination pose a possible source of his exposure to TB infection. More research is needed on this however.

Repeated complete atrioventricular block during remifentanil administration in a pediatric patient with brain tumor and acute hydrocephalus: a case report

BackgroundRemifentanil, an ultra-short-acting µ-opioid receptor agonist, is commonly used for anesthetic management due to excellent adjustability. Remifentanil is known to cause sinus bradycardia, however, because it has a direct negative chronotropic effect on the cardiac conduction system and there is an indirect negative chronotropic effect via the parasympathetic nervous system.Case presentationAn 8-year-old Japanese boy was diagnosed with acute hydrocephalus due to a brain tumor in the fourth ventricle and underwent emergency surgery. Imaging examination showed brainstem compression. Endoscopic third ventriculostomy and ventriculoperitoneal shunt surgery were scheduled. Remifentanil was started during induction of general anesthesia, but electrocardiogram showed sinus bradycardia, then Wenckebach-type atrioventricular block, and then complete atrioventricular block. Remifentanil was immediately discontinued, and we administered atropine sulfate. Complete atrioventricular block was restored to sinus rhythm. When remifentanil was restarted, however, the electrocardiogram again showed sinus bradycardia, Wenckebach-type atrioventricular block, and then complete atrioventricular block. Remifentanil was again immediately discontinued, we administered adrenaline, and then complete atrioventricular block was restored to sinus rhythm. Fentanyl was used instead of remifentanil with continuous infusion of dopamine. There has since been no further occurrence of complete atrioventricular block.ConclusionsThis is the first known case of complete atrioventricular block in a pediatric patient with increased intracranial pressure seemingly caused by administration of remifentanil.

Prognostic Implication of Ventricular Volumetry in Early Brain Computed Tomography after Cardiac Arrest.

Brain swelling after cardiac arrest may affect brain ventricular volume. This study aimed to investigate the prognostic implications of ventricular volume on early thin-slice brain computed tomography (CT) after cardiac arrest. We measured the gray-to-white matter ratio (GWR) and the characteristics and volumes of the lateral, third, and fourth ventricles. The primary outcome was a poor 6-month neurological outcome. Of the 166 patients, 115 had a poor outcome. The fourth ventricle was significantly smaller in the poor outcome group (0.58 cm3 [95% CI, 0.43-0.80]) than in the good outcome group (0.74 cm3 [95% CI, 0.68-0.99], p < 0.001). Ventricular characteristics and other ventricular volumes did not differ between outcome groups. The area under the curve for the fourth ventricular volume was 0.68, comparable to 0.69 for GWR. Lower GWR (<1.09) and lower fourth ventricular volume (<0.41 cm3) predicted poor outcomes with 100% specificity and sensitivities of 8.7% (95% CI, 4.2-15.4) and 20.9% (95% CI, 13.9-29.4), respectively. Combining these measures improved the sensitivity to 25.2% (95% CI, 17.6-34.2). After adjusting for covariates, the fourth ventricular volume was independently associated with neurologic outcome. A marked decrease in fourth ventricular volume, with concomitant hypoattenuation on CT scans, more accurately predicted outcomes.

Hemorrhagic Fourth Ventricle Colloid Cyst: A Report of an Unusual Presentation at an Uncommon Location

AbstractColloid cysts are benign cystic lesions characteristically arising from the third ventricle roof close to the foramen of Monro. Although incredibly rare, hemorrhage within a third ventricular colloid cyst is sparsely reported. To the best of our knowledge, no cases of hemorrhage within the fourth ventricle colloid have ever been documented. Here, we present an interesting case describing a hemorrhagic colloid cyst situated within the fourth ventricle of a 55-year-old female patient who presented with symptoms of headache, vomiting, and gait imbalance. The cyst was excised during surgery via a suboccipital microscopic telovelar approach. Our findings led us to the conclusion that, despite being extremely rare, colloid cysts in the fourth ventricle can present with hemorrhagic episodes, which can exacerbate symptoms and hasten neurological decline. As a result, the presence of unusual radiological characteristics in a fourth ventricle lesion should prompt medical practitioners to suspect an atypical colloid cyst. This consideration can be pivotal in making informed surgical decisions. Expedited management and a microsurgical approach are recommended strategies for a better outcome.