Dmd mdx mice have defective oligodendrogenesis, delayed myelin compaction and persistent hypomyelination.

Duchenne muscular dystrophy (DMD) is caused by mutations in the DMD gene, resulting in the loss of dystrophin, a large cytosolic protein that links the cytoskeleton to extracellular matrix receptors in skeletal muscle. Aside from progressive muscle damage, many patients with DMD also have neurological deficits of unknown etiology. To investigate potential mechanisms for DMD neurological deficits, we assessed postnatal oligodendrogenesis and myelination in the Dmdmdx mouse model. In the ventricular-subventricular zone (V-SVZ) stem cell niche, we found that oligodendrocyte progenitor cell (OPC) production was deficient, with reduced OPC densities and proliferation, despite a normal stem cell niche organization. In the Dmdmdx corpus callosum, a large white matter tract adjacent to the V-SVZ, we also observed reduced OPC proliferation and fewer oligodendrocytes. Transmission electron microscopy further revealed significantly thinner myelin, an increased number of abnormal myelin structures and delayed myelin compaction, with hypomyelination persisting into adulthood. Our findings reveal alterations in oligodendrocyte development and myelination that support the hypothesis that changes in diffusion tensor imaging seen in patients with DMD reflect developmental changes in myelin architecture.

Longitudinal assessment of ventricular volume trajectories in early-stage schizophrenia: evidence of both enlargement and shrinkage.

BACKGROUND: Lateral ventricular enlargement represents a canonical morphometric finding in chronic patients with schizophrenia; however, longitudinal studies elucidating complex dynamic trajectories of ventricular volume change during critical early disease stages are sparse. METHODS: We measured lateral ventricular volumes in 113 first-episode schizophrenia patients (FES) at baseline visit (11.7 months after illness onset, SD = 12.3) and 128 age- and sex-matched healthy controls (HC) using 3T MRI. MRI was then repeated in both FES and HC one year later. RESULTS: Compared to controls, ventricular enlargement was identified in 18.6% of patients with FES (14.1% annual ventricular volume (VV) increase; 95%CI: 5.4; 33.1). The ventricular expansion correlated with the severity of PANSS-negative symptoms at one-year follow-up (p = 0.0078). Nevertheless, 16.8% of FES showed an opposite pattern of statistically significant ventricular shrinkage during ≈ one-year follow-up (-9.5% annual VV decrease; 95%CI: -23.7; -2.4). There were no differences in sex, illness duration, age of onset, duration of untreated psychosis, body mass index, the incidence of Schneiderian symptoms, or cumulative antipsychotic dose among the patient groups exhibiting ventricular enlargement, shrinkage, or no change in VV. CONCLUSION: Both enlargement and ventricular shrinkage are equally present in the early stages of schizophrenia. The newly discovered early reduction of VV in a subgroup of patients emphasizes the need for further research to understand its mechanisms.

Generation of immunocompetent somatic glioblastoma mouse models through in situ transformation of subventricular zone neural stem cells.

Disease-relevant in vivo tumor models are essential tools for both discovery and translational research. Here, we describe a highly genetically tractable technique for generating immunocompetent somatic glioblastoma (GBM) mouse models using piggyBac transposition and CRISPR-Cas9-mediated gene editing in wild-type mice. We describe steps to deliver plasmids into subventricular zone endogenous neural stem cells by injection and electroporation, leading to the development of adult tumors that closely recapitulate the histopathological, molecular, and cellular features of human GBM. For complete details on the use and execution of this protocol, please refer to Garcia-Diaz et al.1.

Validation of a methylation-based signature for subventricular zone involvement in glioblastoma.

PURPOSE: Glioblastomas (GBM) with subventricular zone (SVZ) contact have previously been associated with a specific epigenetic fingerprint. We aim to validate a reported bulk methylation signature to determine SVZ contact. METHODS: Methylation array analysis was performed on IDHwt GBM patients treated at our institution. The v11b4 classifier was used to ensure the inclusion of only receptor tyrosine kinase (RTK) I, II, and mesenchymal (MES) subtypes. Methylation-based assignment (SVZM ±) was performed using hierarchical cluster analysis. Magnetic resonance imaging (MRI) (T1ce) was independently reviewed for SVZ contact by three experienced readers. RESULTS: Sixty-five of 70 samples were classified as RTK I, II, and MES. Full T1ce MRI-based rater consensus was observed in 54 cases, which were retained for further analysis. Epigenetic SVZM classification and SVZ were strongly associated (OR: 15.0, p = 0.003). Thirteen of fourteen differential CpGs were located in the previously described differentially methylated LRBA/MAB21L2 locus. SVZ + tumors were linked to shorter OS (hazard ratio (HR): 3.80, p = 0.02) than SVZM + at earlier time points (time-dependency of SVZM, p < 0.05). Considering the SVZ consensus as the ground truth, SVZM classification yields a sensitivity of 96.6%, specificity of 36.0%, positive predictive value (PPV) of 63.6%, and negative predictive value (NPV) of 90.0%. CONCLUSION: Herein, we validated the specific epigenetic signature in GBM in the vicinity of the SVZ and highlighted the importance of methylation of a part of the LRBA/MAB21L2 gene locus. Whether SVZM can replace MRI-based SVZ assignment as a prognostic and diagnostic tool will require prospective studies of large, homogeneous cohorts.

High-Grade Gliomas from Subventricular Zone: Proteomic Drivers of Aggressiveness Using Fluorescence-Guided Multiple Sampling.

High-grade gliomas (HGGs) are among the most aggressive brain tumors and are characterized by dismally low median survival time. Of the many factors influencing the survival of patients with HGGs, proximity to the subventricular zone (SVZ) is one of the key influencers. In this context, 5-amino levulinic acid fluorescence-guided multiple sampling (FGMS) offers the prospect of understanding patient-to-patient molecular heterogeneity driving the aggressiveness of these tumors. Using high-resolution liquid chromatography-mass spectrometry (MS)/MS proteomics for HGGs from seven patients (four SVZ associated and three SVZ nonassociated), this study aimed to uncover the mechanisms driving the aggressiveness in SVZ-associated (SVZ+) HGGs. Differential proteomics analysis revealed significant dysregulation of 11 proteins, of which 9 proteins were upregulated and 2 were downregulated in SVZ+ HGGs compared to SVZ-non-associated (SVZ-) HGGs. The gene set enrichment analysis (GSEA) of the proteomics dataset revealed enrichment of MYC targets V1 and V2, G2M checkpoints, and E2F targets in SVZ+ HGGs. With GSEA, we also compared the pathways enriched in glioma stem cell subpopulations and observed a similar expression trend for most pathways in our data. In conclusion, this study reveals new and emerging insights on pathways that may potentially contribute to greater aggressiveness in SVZ+ HGGs. Future studies using FGMS in larger cohorts are recommended to help uncover the proteomics and molecular basis of aggressiveness and stemness in HGGs.

Clinicogenetic characteristics and the effect of radiation on the neural stem cell niche in subventricular zone-contacting glioblastoma.

BACKGROUND AND PURPOSE: Neural stem cells (NSCs) in the subventricular zone (SVZ) are recognized as the cellular origin of glioblastoma (GBM) and a potential therapeutic target. However, the characteristics of SVZ contacting GBM (SVZ + GBM) and radiotherapeutic strategies for NSCs are still controversial. Here, we investigated the clinicogenetic features of SVZ + GBM and evaluated the dose effect of NSC irradiation depending on SVZ involvement. MATERIALS AND METHODS: We identified 125 patients with GBM treated with surgery followed by chemoradiotherapy. The genomic profiles were obtained by next-generation sequencing targeting 82 genes. NSCs in the SVZ and hippocampus were contoured using standardized methods, and dosimetric factors were analyzed. SVZ + GBM was defined as GBM with SVZ involvement in a T1 contrast-enhanced image. Progression-free survival (PFS) and overall survival (OS) were used as endpoints. RESULTS: The number of patients with SVZ + GBM was 95 (76%). SVZ + GBM showed lower PFS than GBM without SVZ involvement (SVZ-GBM) (median 8.6 vs. 11.5 months, p = 0.034). SVZ contact was not associated with any specific genetic profile but was an independent prognostic factor in multivariate analysis. In SVZ + GBM, patients receiving high doses to the ipsilateral NSC region showed significantly better OS (HR = 1.89, p = 0.011) and PFS (HR = 1.77, p = 0.013). However, in SVZ-GBM, high doses to the ipsilateral NSC region were associated with worse OS (HR = 0.27, p = 0.013) and PFS (HR = 0.37, p = 0.035) in both univariate and multivariate analyses. CONCLUSION: SVZ involvement in GBM was not associated with distinct genetic features. However, irradiation of NSCs was associated with better prognosis in patients with tumors contacting the SVZ.

Targeting the neural stem cells in subventricular zone for the treatment of glioblastoma: an update from preclinical evidence to clinical interventions.

BACKGROUND: Glioblastoma is one of the most common and aggressive adult brain tumors. The conventional treatment strategy, surgery combined with chemoradiotherapy, did not change the fact that the recurrence rate was high and the survival rate was low. Over the years, accumulating evidence has shown that the subventricular zone has an important role in the recurrence and treatment resistance of glioblastoma. The human adult subventricular zone contains neural stem cells and glioma stem cells that are probably a part of reason for therapy resistance and recurrence of glioblastoma. MAIN BODY: Over the years, both bench and bedside evidences strongly support the view that the presence of neural stem cells and glioma stem cells in the subventricular zone may be the crucial factor of recurrence of glioblastoma after conventional therapy. It emphasizes the necessity to explore new therapy strategies with the aim to target subventricular zone to eradicate neural stem cells or glioma stem cells. In this review, we summarize the recent preclinical and clinical advances in targeting neural stem cells in the subventricular zone for glioblastoma treatment, and clarify the prospects and challenges in clinical application. CONCLUSIONS: Although there remain unresolved issues, current advances provide us with a lot of evidence that targeting the neural stem cells and glioma stem cells in subventricular zone may have the potential to solve the dilemma of glioblastoma recurrence and treatment resistance.

An immunosuppressed microenvironment distinguishes lateral ventricle-contacting glioblastomas.

Radiographic contact of glioblastoma (GBM) tumors with the lateral ventricle and adjacent stem cell niche correlates with poor patient prognosis, but the cellular basis of this difference is unclear. Here, we reveal and functionally characterize distinct immune microenvironments that predominate in subtypes of GBM distinguished by proximity to the lateral ventricle. Mass cytometry analysis of isocitrate dehydrogenase wild-type human tumors identified elevated T cell checkpoint receptor expression and greater abundance of a specific CD32+CD44+HLA-DRhi macrophage population in ventricle-contacting GBM. Multiple computational analysis approaches, phospho-specific cytometry, and focal resection of GBMs validated and extended these findings. Phospho-flow quantified cytokine-induced immune cell signaling in ventricle-contacting GBM, revealing differential signaling between GBM subtypes. Subregion analysis within a given tumor supported initial findings and revealed intratumor compartmentalization of T cell memory and exhaustion phenotypes within GBM subtypes. Collectively, these results characterize immunotherapeutically targetable features of macrophages and suppressed lymphocytes in GBMs defined by MRI-detectable lateral ventricle contact.

Tightened Sulci in the High Convexities as a Noteworthy Feature of Idiopathic Normal Pressure Hydrocephalus.

OBJECTIVE: The presence of tightened sulci in the high-convexities (THC) is a key morphological feature for the diagnosis of idiopathic normal pressure hydrocephalus (iNPH), but the exact localization of THC has yet to be defined. The purpose of this study was to define THC and compare its volume, percentage, and index between iNPH patients and healthy controls. METHODS: According to the THC definition, the high-convexity part of the subarachnoid space was segmented and measured the volume and percentage from the 3D T1-weighted and T2-weighted magnetic resonance images in 43 patients with iNPH and 138 healthy controls. RESULTS: THC was defined as a decrease in the high-convexity part of the subarachnoid space located above the body of the lateral ventricles, with anterior end on the coronal plane perpendicular to the anterior commissure-posterior commissure (AC-PC) line passing through the front edge of the genu of corpus callosum, the posterior end in the bilateral posterior parts of the callosomarginal sulci, and the lateral end at 3 cm from the midline on the coronal plane perpendicular to the AC-PC line passing through the midpoint between AC and PC. Compared to the volume and volume percentage, the high-convexity part of the subarachnoid space volume per ventricular volume ratio < 0.6 was the most detectable index of THC on both 3D T1-weighted and T2-weighted magnetic resonance images. CONCLUSIONS: To improve the diagnostic accuracy of iNPH, the definition of THC was clarified, and high-convexity part of the subarachnoid space volume per ventricular volume ratio <0.6 proposed as the best index for THC detection in this study.

Defining subventricular zone involvement to predict the survival of patients in isocitrate dehydrogenase-wild type glioblastoma: validation in a prospective registry.

OBJECTIVES: The prognostic value of subventricular zone distance (SVD) is unclear because of different definitions and lack of evaluation of clinical survival models. The aim of this study was to define SVD and evaluate its prognostic value in a survival nomogram for glioblastoma. METHODS: This retrospective study included 158 (SVD biomarker) from historical glioblastoma patients and 187 (survival modeling) with IDH-wild type glioblastoma from a prospective registry (NCT02619890). SVD was assessed by two radiologists: definition 1, the distance between the tumor edge to subventricular zone (SVZ); definition 2, the distance between the tumor centroid to SVZ; definition 3, enhancement at the ventricular wall. The associations between SVD and overall survival (OS) were evaluated using multivariable Cox proportional hazards regression analysis. Performance of an updated SVD survival model was compared with that of the Radiation Therapy Oncology Group (RTOG) 0525 nomogram. RESULTS: SVD according to both definition 1 (hazard ratio [HR]: 0.97, 95% CI: 0.94-0.99; p = .011) and definition 2 (HR: 0.96, 0.94-0.98, p < .001) was adversely associated with OS. Definition 1 was adversely associated with PFS (HR: 0.96, 0.94-0.99, p = .008) and showed the highest reproducibility (intraclass correlation coefficient, 0.90). The SVD-updated model showed similar to better performance than the RTOG model for predicting OS of up to 3 years (AUC: 0.735-0.738 vs. 0.687-0.708), with higher time-dependent specificity for 1-year (89.9% vs. 70.6%) and 3-year OS (93.3% vs. 80.0%). CONCLUSION: SVZ distance is an independent adverse prognostic factor in patients with IDH-wild type glioblastoma. Updating the survival model with SVZ provides better time-dependent specificity and reproducibility. KEY POINTS: • Subventricular zone distance (SVD) measurement from tumor edge showed high reproducibility. • Longer SVD was independently associated with longer overall survival. • Adding SVD improved time-dependent specificity for survival model in a prospective registry.

Acquired hump of the corpus callosum: a rare morphologic complication after CSF shunting.

PURPOSE: To present the longitudinal MR imaging of 4 children with an acquired corpus callosum hump, in order to demonstrate graphically that this represents a dysmorphology caused through a constellation of pre-existing pathology, timing, and complications of treatment. MATERIALS AND METHODS: Four cases with a corpus callosum hump were evaluated for common findings in the clinical history and on MRI scans. Those patients with available follow-up imaging were specifically evaluated for the presence of the hump on initial neonatal imaging and for evidence of development and progression of the deformity over time. Corpus callosum length was measured and compared against normal standards. RESULTS AND CONCLUSION: Congenital hydrocephalus, chronic ventricular over-shunting, white matter volume loss, and lateral ventricle communication were common to all cases. Corpus callosum length was above normal values. The corpus callosum hump term was previously described as dysplasia but was not present on initial scans in our cases. We conclude that the corpus callosum hump can be acquired as a complication of over-shunting in children with congenital hydrocephalus. Thus, we present our examples as "acquired hump of the corpus callosum," which differs from the prior example. We postulate that the lengthening of the stretched corpus callosum due to chronic hydrocephalus in the pre-myelinated state renders it unable to return to its normal shape when the ventricles are drained. Over-shunting of both lateral ventricles simultaneously in the absence of a septum pellucidum results in collapse and folding in of the corpus callosum on itself, resulting in the hump.

MR Imaging, MGMT Promoter Methylation Features and Prognostic Analysis of Subventricular Zone Contacting IDH Wild-type Glioblastoma.

BACKGROUND: As the largest concentration of neural stem cells in adult brain, the subventricular zone (SVZ) is considered to be a potential source of glioblastoma (GBM) occurrence in recent years. METHODS: In this study, 116 patients with glioblastoma treated at PLA General Hospital were retrospectively reviewed. The features of SVZ contacting glioblastoma were analyzed in terms of MR imaging and MGMT promoter methylation. We also evaluated the prognostic value of SVZ contacting in GBM patients. RESULTS: GBM with SVZ involvement on MRI is more likely to grow across the midline (36.8% vs. 6.9%, P=0.002), more often multifocal lesion (35.6% vs. 6.9%, P=0.003) and have a lower proportion of MGMT promoter methylation (36.8% vs. 69.0%, P=0.003). The median overall survival and progression- free survival of patients in the SVZ contacting group were 12 months and 7 months, while 25 months and 17 months in the non-contacting group (P<0.001, respectively). There was no significant difference in overall survival (P=0.229) and progression-free survival (P=0.808) between patients with different SVZ contacting regions. Multivariate survival analysis indicated that patients with MRI SVZ involvement showed worse overall survival (HR=2.060, 95%CI 1.195-3.550，P=0.009) and progression- free survival (HR=3.021, 95%CI 1.788-5.104，P＜0.001). CONCLUSION: This study suggested that MRI SVZ involvement at diagnosis is an independent risk factor for overall survival and progression-free survival in IDH wild-type glioblastoma patients. Based on MR imaging, we also found that SVZ contacting glioblastomas had a larger proportion of crossing midline tumors and multifocal lesions. In addition, patients with SVZ contact in our research presented a lower proportion of MGMT promoter methylation.

Machine learning-based multiparametric magnetic resonance imaging radiomics model for distinguishing central neurocytoma from glioma of lateral ventricle.

OBJECTIVES: To develop a machine learning-based radiomics model based on multiparametric magnetic resonance imaging (MRI) for preoperative discrimination between central neurocytomas (CNs) and gliomas of lateral ventricles. METHODS: A total of 132 patients from two medical centers were enrolled in this retrospective study. Patients from the first medical center were divided into a training cohort (n = 74) and an internal validation cohort (n = 30). Patients from the second medical center were used as the external validation cohort (n = 28). Features were extracted from contrast-enhanced T1-weighted and T2-weighted images. A support vector machine was used for radiomics model investigation. Performance was evaluated using the sensitivity, specificity, and the area under the receiver operating characteristic curve (AUC). The model's performance was also compared with those of three radiologists. RESULTS: The radiomics model achieved an AUC of 0.986 in the training cohort, 0.933 in the internal validation cohort, and 0.903 in the external validation cohort. In the three cohorts, the AUC values were 0.657, 0.786, and 0.708 for radiologist 1; 0.838, 0.799, and 0.790 for radiologist 2; and 0.827, 0.871, and 0.862 for radiologist 3. When assisted by the radiomics model, two radiologists improved their performance in the training cohort (p < 0.05) but not in the internal or external validation cohorts. CONCLUSIONS: The machine learning radiomics model based on multiparametric MRI showed better performance for distinguishing CNs from lateral ventricular gliomas than did experienced radiologists, and it showed the potential to improve radiologist performance. KEY POINTS: • The machine learning radiomics model shows excellent performance in distinguishing CNs from gliomas. • The radiomics model outweighs two experienced radiologists (area under the receiver operating characteristic curve, 0.90 vs 0.79 and 0.86, respectively). • The radiomics model has the potential to enhance radiologist performance.

Intracranial germinoma in the lateral ventricle with polydipsia and polyuria: a case report and literature review.

Central nervous system germ cell tumors (CNSGCTs) are rare neoplasms which usually develop in the midline structures. They are occasionally involved in off-midline structures of the brain. Here, we report an extremely rare case of an intracranial germinoma in the lateral ventricle. The patient was a 10-year-old boy with a 1-year history of polydipsia and polyuria. Brain magnetic resonance imaging (MRI) showed a relatively homogeneously enhancing lesion in the lateral ventricle, and the posterior pituitary gland was not hyperintense on T1-weighted imaging. Subependymoma was suspected, and tumor removal operation was performed; however, because the intraoperative pathological investigation revealed germinoma, we could only perform partial removal of the tumor. Postoperative histology also confirmed germinoma. Then, the patient received chemotherapy, followed by radiation therapy. MRI showed no recurrence for 6 years after treatment. Intracranial germinoma in the lateral ventricle is extremely rare. The diagnosis is occasionally challenging, especially when the tumors are located in atypical locations. This paper presents a literature review of previously described CNSGCTs of the lateral ventricle to improve awareness of CNSGCTs in atypical locations. We also consider the relationship between imaging findings and clinical manifestations.

Lateral ventricle meningiomas in children: clinicopathological and neuroradiological features.

PURPOSE: Lateral ventricle meningiomas (LVM) in children are very rare. The current research is mostly limited to adults, and there are very few related studies on children. The purpose of this study was to analyze the clinicopathological and imaging features of lateral ventricle meningiomas in children. METHODS: A retrospective analysis of five children with pathologically confirmed lateral ventricle meningioma was performed, and we collected clinical data, including clinicopathological data, treatment prognosis data, and imaging features (including tumor location, signal intensity, enhancement degree, intratumoral cyst, calcification, peritumoral edema, and associated hydrocephalus). RESULTS: Among the 5 patients with LVM, 4 were male and 1 was female with an average age of 7.6 years (range 2 to 12 years). All CT scans showed slight hyperintensity or isodensity, and only 1 patient had calcification. Two patients demonstrated cyst changes. Four patients had varying degrees of peritumoral edema. The average tumor volume was 164.1 cm3 (1.4-314.9 cm3). All 5 patients with LVM were iso- or hypointense on T1WI. The T2WI signals had no obvious features. Four patients had a high signal on DWI (80%). The contrast-enhanced signals were mostly homogeneously strong (80%). MRI showed hydrocephalus in 3 patients. All patients underwent gross total resection, and they were followed up regularly after the operation. The average follow-up time was 47.4 months. No recurrence was found in any of the children. All patients were pathologically confirmed to have meningiomas, and WHO grades were all grade I. CONCLUSION: Lateral ventricle meningiomas in children are very rare, and the imaging manifestations of the tumor have certain characteristics, but the clinical diagnosis is still difficult, and the diagnosis still requires pathological analysis.

The imaging features and prognosis of gliomas involving the subventricular zone: An MRI study.

RATIONALE AND OBJECTIVES: As the largest concentrated region of neural stem cells in the adult brain, the subventricular zone (SVZ) is considered to have a close relationship with the origin of gliomas. An in-depth study of the characteristic manifestations associated with SVZ involvement in glioma may provide new ideas for individualized diagnosis and treatment of this fatal disease. MATERIALS AND METHODS: All 279 patients with glioma who underwent surgical treatment in our department from January 2016 to December 2021 were included. Clinical and imaging data were collected, and telephonic follow-up was conducted to analyze the overall survival and progression-free survival. Prognostic factors including SVZ involvement on glioblastoma patients' survival were analyzed. Next, the relationship between SVZ involvement, a set of unique imaging features and gene status were determined respectively. The chi-squared test, logistics regression, and Cox regression were used for statistical analysis. RESULTS: The patients were divided into the SVZ involvement group (n = 198, 70.97 %) and SVZ non-involvement group (n = 81, 29.03 %). The median overall survival and progression-free survival were 13 months and 7 months for the SVZ involvement group, but 25 months and 17 months for the SVZ non-involvement group, respectively. In multivariate Cox survival analysis, MRI SVZ involvement proved an independent risk factor for the survival of patients with glioblastoma. The patients with SVZ involvement sign had a lower rate of cystic lesion (32.32 % vs. 48.48 %, p = 0.029), and a larger mean maximum diameter (5.88 ± 1.28 vs. 3.28 ± 1.65 cm). Compared with high grade gliomas (HGG), T1 enhancement (25.25 % vs. 10.42 %, p = 0.041) and homogeneous signal on T2WI (14.14 % vs. 43.75 %, p = 0.025) were independently associated with SVZ involvement in WHO grade 2 gliomas(LGG). In the gene status analysis, the SVZ involvement group showed the lower rate of MGMT promoter methylation (57.58 % vs. 79.17 %, p = 0.017). CONCLUSION: SVZ involvement in MRI at diagnosis is an independent negative prognostic indicator for the survival of glioblastoma patients. Some image signs are associated with SVZ involvement in HGG and LGG respectively. The unique imaging and gene features of gliomas with SVZ involvement indicate that this kind of tumor maybe a unique subgroup of gliomas.

Prophylactic Intraventricular Piping Method Prevents Entrapped Temporal Horn After Removal of Ventricle Trigone Meningioma: Technical Note.

BACKGROUND: An entrapped temporal horn (ETH) is one of the critical complications after tumor removal in the lateral ventricle trigone that sometimes becomes life threatening. OBJECTIVE: We sought to develop a novel intraoperative method of prophylactic intraventricular piping (PIP) just after tumor removal to prevent ETH. METHODS: Three patients with meningiomas in the lateral ventricle trigone were treated by a novel intraoperative method of PIP just after tumor removal to prevent ETH. Silicone catheters normally used as ventricular drainage catheters were cut to 5- to 6-cm length and inserted into the tumor cavity to ensure communication between the temporal horn and the atrium or the body of the lateral ventricle through the piping straddling the trigone. RESULTS: None of our patients developed ETH during the follow-up period without complications caused by the tube placement. CONCLUSIONS: PIP might be beneficial to prevent ETH because constant osmotic pressure and constant cerebrospinal fluid pulse wave transmission are maintained between each compartment of the lateral ventricle.

Lateral ventricle pleomorphic xanthoastrocytoma concurrent with Dandy-Walker complex: A case report.

INTRODUCTION: Dandy-Walker complex and pleomorphic xanthoastrocytomas are both rare disease entities that typically manifest early in life and are associated with congenital etiological factors. Dandy-Walker complex is a cerebellar malformation associated with a series of anatomical changes. The disease onset is usually at birth or during infancy. Late onset in adulthood is uncommon. Pleomorphic xanthoastrocytoma is a rare WHO grade II astrocytic tumor affecting mainly young adults. Concomitant occurrence of Dandy-Walker complex and pleomorphic xanthoastrocytoma has not been previously reported. PATIENT CONCERNS AND DIAGNOSIS: A 30-year-old woman with a previous history of unconfirmed resected lateral ventricle meningioma presented with severe headache for 1 day. Imaging examination revealed a mass in the right lateral ventricle with heterogeneous signal patterns, changes in the posterior fossa corresponding to a Dandy-Walker variant, and mild hydrocephalus. INTERVENTIONS AND OUTCOMES: Surgical complete resection of the mass was achieved. postoperative histopathological examination confirmed WHO grade II pleomorphic xanthoastrocytoma. Three years postsurgery, ventriculoperitoneal shunt was performed due to worsening of hydrocephalus. The patient has since remained symptom-free. CONCLUSION: This is the first report of concomitant occurrence of Dandy-Walker complex and pleomorphic xanthoastrocytoma. The association of neurological congenital malformation with intracranial neoplasms may be multifactorial, with underlying role of genetic mutations or chromosome alterations.