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Glioblastoma is the most common and malignant type of primary brain tumor. Previous studies have shown that alterations in centrosome amplification and its components are frequently found in treatment-resistant tumors and may be associated with tumor progression. A centrosome protein essential for centrosome biogenesis is the centromere protein J (CENPJ), known to control the proliferation of neural progenitors and hepatocarcinoma cells, and also neuronal migration. However, it remains unknown the role of CENPJ in glioblastoma. Here we show that CENPJ is overexpressed in human glioblastoma cell lines in comparison to human astrocytes. Using bioinformatics analysis, we find that high Cenpj expression is associated with poor prognosis in glioma patients. Examining Cenpj loss of function in glioblastoma by siRNA transfection, we find impairments in cell proliferation and migration. Using a Cenpj mutant version with the deleted PN2-3 or TCP domain, we found that a conserved PN2-3 region is required for glioblastoma migration. Moreover, Cenpj downregulation modulates glioblastoma morphology resulting in microtubules stabilization and actin filaments depolymerization. Altogether, our findings indicate that CENPJ controls relevant aspects of glioblastoma progression and might be a target for therapeutic intervention and a biomarker for glioma malignancy.

Glioblastoma is the most life‐threatening tumour of the central nervous system. Temozolomide (TMZ) is the first‐choice oral drug for the treatment of glioblastoma, although it shows low efficacy. Silver nanoparticles (AgNPs) have been shown to exhibit biocidal activity in a variety of microorganisms, including some pathogenic microorganisms. Herein, the antiproliferative effect of AgCl‐NPs on glioblastoma cell lines (GBM02 and GBM11) and on astrocytes was evaluated through automated quantitative image‐based analysis (HCA) of the cells. The cells were treated with 0.1‐5.0 μg/ml AgCl‐NPs or with 9.7‐48.5 μg/ml TMZ. Cells that received combined treatment were also analysed. At a maximum tested concentration of AgCl‐NPs, GBM02 and GBM11, the growth decreased by 93% and 40%, respectively, following 72 h of treatment. TMZ treatment decreased the proliferation of GBM02 and GBM11 cells by 58% and 34%, respectively. Combinations of AgCl‐NPs and TMZ showed intermediate antiproliferative effects; the lowest concentrations caused an inhibition similar to that obtained with TMZ, and the highest concentrations caused inhibition similar to that obtained with AgCl‐NPs alone. No significant changes in astrocyte proliferation were observed. The authors’ findings showed that HCA is a fast and reliable approach that can be used to evaluate the antiproliferative effect of the nanoparticles at the single‐cell level and that AgCl‐NPs are promising agents for glioblastoma treatment.

Neurological complications affecting the central nervous system have been reported in adult patients infected by Zika virus (ZIKV) but the underlying mechanisms remain unknown. Here, we report that ZIKV replicates in human and mouse adult brain tissue, targeting mature neurons. ZIKV preferentially targets memory-related brain regions, inhibits hippocampal long-term potentiation and induces memory impairment in adult mice. TNF-α upregulation, microgliosis and upregulation of complement system proteins, C1q and C3, are induced by ZIKV infection. Microglia are found to engulf hippocampal presynaptic terminals during acute infection. Neutralization of TNF-α signaling, blockage of microglial activation or of C1q/C3 prevent synapse and memory impairment in ZIKV-infected mice. Results suggest that ZIKV induces synapse and memory dysfunction via aberrant activation of TNF-α, microglia and complement. Our findings establish a mechanism by which ZIKV affects the adult brain, and point to the need of evaluating cognitive deficits as a potential comorbidity in ZIKV-infected adults., Here, using ex-vivo human adult cortical tissue and a mouse model, the authors investigate the functional consequences of Zika virus (ZIKV) infection in the adult brain, and show that ZIKV causes synapse damage and altered brain function that impacts cognition via activation of innate and inflammatory factors.

Parkinson's disease (PD) is characterized by selective death of dopaminergic neurons in the substantia nigra, degeneration of the nigrostriatal pathway, increases in glutamatergic synapses in the striatum and aggregation of α-synuclein. Evidence suggests that oligomeric species of α-synuclein (αSO) are the genuine neurotoxins of PD. Although several studies have supported the direct neurotoxic effects of αSO on neurons, their effects on astrocytes have not been directly addressed. Astrocytes are essential to several steps of synapse formation and function, including secretion of synaptogenic factors, control of synaptic elimination and stabilization, secretion of neural/glial modulators, and modulation of extracellular ions, and neurotransmitter levels in the synaptic cleft. Here, we show that αSO induced the astrocyte reactivity and enhanced the synaptogenic capacity of human and murine astrocytes by increasing the levels of the known synaptogenic molecule transforming growth factor beta 1 (TGF-β1). Moreover, intracerebroventricular injection of αSO in mice increased the number of astrocytes, the density of excitatory synapses, and the levels of TGF-β1 in the striatum of injected animals. Inhibition of TGF-β1 signaling impaired the effect of the astrocyte-conditioned medium on glutamatergic synapse formation in vitro and on striatal synapse formation in vivo, whereas addition of TGF-β1 protected mesencephalic neurons against synapse loss triggered by αSO. Together, our data suggest that αSO have important effects on astrocytic functions and describe TGF-β1 as a new endogenous astrocyte-derived molecule involved in the increase in striatal glutamatergic synaptic density present in early stages of PD. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/. Cover Image for this issue: doi: 10.1111/jnc.14514.

Arboviruses pose a major threat throughout the world and represent a great burden in tropical countries of South America. Although generally associated with moderate febrile illness, in more severe cases they can lead to neurological outcomes, such as encephalitis, Guillain-Barré syndrome, and Congenital Syndromes. In this context astrocytes play a central role in production of inflammatory cytokines, regulation of extracellular matrix, and control of glutamate driven neurotoxicity in the central nervous system. Here, we presented a comprehensive genome-wide transcriptome analysis of human primary astrocytes infected with Chikungunya, Mayaro, Oropouche, or Zika viruses. Analyses of differentially expressed genes (DEGs), pathway enrichment, and interactomes have shown that Alphaviruses up-regulated genes related to elastic fiber formation and N-glycosylation of glycoproteins, with down-regulation of cell cycle and DNA stability and chromosome maintenance genes. In contrast, Oropouche virus up-regulated cell cycle and DNA maintenance and condensation pathways while down-regulated extracellular matrix, collagen metabolism, glutamate and ion transporters pathways. Zika virus infection only up-regulated eukaryotic translation machinery while down-regulated interferon pathways. Reactome and integration analysis revealed a common signature in down-regulation of innate immune response, antiviral response, and inflammatory cytokines associated to interferon pathway for all arboviruses tested. Validation of interferon stimulated genes by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) corroborated our transcriptome findings. Altogether, our results showed a co-evolution in the mechanisms involved in the escape of arboviruses to antiviral immune response mediated by the interferon (IFN) pathway.

Backgrounds: Cerebral Cavernous Malformations (CCM) predispose patients to a lifetime risk of seizures and symptomatic hemorrhage. Only a small percentage of people affected will develop clinical symptoms and the molecular mechanisms underlying lesional activity remain unclear. We analyzed a panel of Single Nucleotide Polymorphisms (SNPs) in CCM patients. We looked for plasmatic inflammatory cytokines, checking for a pattern of plasma expression heterogeneity and any correlation with genetic variations identified with different CCM clinical phenotypes. Methods: This was a case-control study from a long-term follow-up cohort including 23 CCM patients, of which 16 were symptomatic, and 7 were asymptomatic. A 200-SNP panel was considered through next-generation sequencing and 18 different plasma molecules were assessed through a suspension array system. Results: Fcγ receptor IIa rs1801274 (FCGR2A) and protein tyrosine phosphatase non-receptor type 2 rs72872125 PTPN2 were statistically different between groups. Patients who had a combination of the presence of FCGR2A and the absence of PTPN2 also had symptoms earlier in life. The combination of genetic polymorphisms and serum level of GM-CSF showed the best diagnostic biomarker to distinguish symptomatic patients as formulated: [0.296*(FCGR2A)] + [-0.788*(PTPN2)] + [-0.107*(GM-CSF)]. Conclusion: We have shown that SNPs in inflammation genes might be related to a symptomatic phenotype in CCM. We also demonstrated that a formula based on two of these polymorphisms (FCGR2A+ and PTPN2+) is possibly capable of predicting a symptomatic phenotype during a patient’s lifetime.

Despite advances in treatment of lethal prostate cancer, the incidence of prostate cancer brain metastases is increasing. In this sense, we analyzed the molecular profile, as well as the functional consequences involved in the reciprocal interactions between prostate tumor cells and human astrocytes. We observed that the DU145 cells, but not the LNCaP cells or the RWPE-1 cells, exhibited more pronounced, malignant and invasive phenotypes along their interactions with astrocytes. Moreover, global gene expression analysis revealed several genes that were differently expressed in our co-culture models with the overexpression of GLIPR1 and SPARC potentially representing a molecular signature associated with the invasion of central nervous system by prostate malignant cells. Further, these results were corroborated by immunohistochemistry and in silico analysis. Thus, we conjecture that the data here presented may increase the knowledge about the molecular mechanisms associated with the invasion of CNS by prostate malignant cells.

Alzheimer's disease (AD) is characterized by progressive cognitive decline, increasingly attributed to neuronal dysfunction induced by amyloid-β oligomers (AβOs). Although the impact of AβOs on neurons has been extensively studied, only recently have the possible effects of AβOs on astrocytes begun to be investigated. Given the key roles of astrocytes in synapse formation, plasticity, and function, we sought to investigate the impact of AβOs on astrocytes, and to determine whether this impact is related to the deleterious actions of AβOs on synapses. We found that AβOs interact with astrocytes, cause astrocyte activation and trigger abnormal generation of reactive oxygen species, which is accompanied by impairment of astrocyte neuroprotective potential in vitro. We further show that both murine and human astrocyte conditioned media (CM) increase synapse density, reduce AβOs binding, and prevent AβO-induced synapse loss in cultured hippocampal neurons. Both a neutralizing anti-transforming growth factor-β1 (TGF-β1) antibody and siRNA-mediated knockdown of TGF-β1, previously identified as an important synaptogenic factor secreted by astrocytes, abrogated the protective action of astrocyte CM against AβO-induced synapse loss. Notably, TGF-β1 prevented hippocampal dendritic spine loss and memory impairment in mice that received an intracerebroventricular infusion of AβOs. Results suggest that astrocyte-derived TGF-β1 is part of an endogenous mechanism that protects synapses against AβOs. By demonstrating that AβOs decrease astrocyte ability to protect synapses, our results unravel a new mechanism underlying the synaptotoxic action of AβOs in AD. SIGNIFICANCE STATEMENT Alzheimer's disease is characterized by progressive cognitive decline, mainly attributed to synaptotoxicity of the amyloid-β oligomers (AβOs). Here, we investigated the impact of AβOs in astrocytes, a less known subject. We show that astrocytes prevent synapse loss induced by AβOs, via production of transforming growth factor-β1 (TGF-β1). We found that AβOs trigger morphological and functional alterations in astrocytes, and impair their neuroprotective potential. Notably, TGF-β1 reduced hippocampal dendritic spine loss and memory impairment in mice that received intracerebroventricular infusions of AβOs. Our results describe a new mechanism underlying the toxicity of AβOs and indicate novel therapeutic targets for Alzheimer's disease, mainly focused on TGF-β1 and astrocytes.

Glioblastoma (GBM) is a grade IV astrocytoma. GBM patients show resistance to chemotherapy such as temozolomide (TMZ), the gold standard treatment. In order to simulate the molecular mechanisms behind the different chemotherapeutic responses in GBM patients we compared the cellular heterogeneity and chemotherapeutic resistance mechanisms in different GBM cell lines. We isolated and characterized a human GBM cell line obtained from a GBM patient, named GBM11. We studied the GBM11 behaviour when treated with Tamoxifen (TMX) that, among other functions, is a protein kinase C (PKC) inhibitor, alone and in combination with TMZ in comparison with the responses of U87 and U118 human GBM cell lines. We evaluated the cell death, cell cycle arrest and cell proliferation, mainly through PKC expression, by flow cytometry and western blot analysis and, ultimately, cell migration capability and F-actin filament disorganization by fluorescence microscopy. We demonstrated that the constitutive activation of p-PKC seems to be one of the main metabolic implicated on GBM malignancy. Despite of its higher resistance, possibly due to the overexpression of P-glycoprotein and stem-like cell markers, GBM11 cells presented a subtle different chemotherapeutic response compared to U87 and U118 cells. The GBM11, U87, U118 cell lines show subtle molecular differences, which clearly indicate the characterization of GBM heterogeneity, one of the main reasons for tumor resistance. The adding of cellular heterogeneity in molecular behaviour constitutes a step closer in the understanding of resistant molecular mechanisms in GBM, and can circumvents the eventual impaired therapy.

Brain accumulation of the amyloid-β protein (Aβ) and synapse loss are neuropathological hallmarks of Alzheimer disease (AD). Aβ oligomers (AβOs) are synaptotoxins that build up in the brains of patients and are thought to contribute to memory impairment in AD. Thus, identification of novel synaptic components that are targeted by AβOs may contribute to the elucidation of disease-relevant mechanisms. Trans-synaptic interactions between neurexins (Nrxs) and neuroligins (NLs) are essential for synapse structure, stability, and function, and reduced NL levels have been associated recently with AD. Here we investigated whether the interaction of AβOs with Nrxs or NLs mediates synapse damage and cognitive impairment in AD models. We found that AβOs interact with different isoforms of Nrx and NL, including Nrx2α and NL1. Anti-Nrx2α and anti-NL1 antibodies reduced AβO binding to hippocampal neurons and prevented AβO-induced neuronal oxidative stress and synapse loss. Anti-Nrx2α and anti-NL1 antibodies further blocked memory impairment induced by AβOs in mice. The results indicate that Nrx2α and NL1 are targets of AβOs and that prevention of this interaction reduces the deleterious impact of AβOs on synapses and cognition. Identification of Nrx2α and NL1 as synaptic components that interact with AβOs may pave the way for development of novel approaches aimed at halting synapse failure and cognitive loss in AD.

AMP-activated kinase (AMPK) is a key player in energy sensing and metabolic reprogramming under cellular energy restriction. Several studies have linked impaired AMPK function to peripheral metabolic diseases such as diabetes. However, the impact of neurological disorders, such as Alzheimer disease (AD), on AMPK function and downstream effects of altered AMPK activity on neuronal metabolism have been investigated only recently. Here, we report the impact of Aβ oligomers (AβOs), synaptotoxins that accumulate in AD brains, on neuronal AMPK activity. Short-term exposure of cultured rat hippocampal neurons or ex vivo human cortical slices to AβOs transiently decreased intracellular ATP levels and AMPK activity, as evaluated by its phosphorylation at threonine residue 172 (AMPK-Thr(P)172). The AβO-dependent reduction in AMPK-Thr(P)172 levels was mediated by glutamate receptors of the N-methyl-d-aspartate (NMDA) subtype and resulted in removal of glucose transporters (GLUTs) from the surfaces of dendritic processes in hippocampal neurons. Importantly, insulin prevented the AβO-induced inhibition of AMPK. Our results establish a novel toxic impact of AβOs on neuronal metabolism and suggest that AβO-induced, NMDA receptor-mediated AMPK inhibition may play a key role in early brain metabolic defects in AD.

Background Intraorbital and intracerebral cavernous malformation (CM) lesions are considered independent entities. Purely cerebral CMs have variable biology with recent evidence depicting inflammation as an important player and a risk factor for aggressiveness. We describe a case of concomitant left intraaxial and extraaxial CMs, linked by the ipsilateral basal vein, where the extraaxial component has developed an aggressive behavior. Case Description A 35-year-old female patient presented with a rapid and progressive exophthalmos and loss of vision on the left eye. Cranial magnetic resonance and angiography examinations demonstrated a left craniofacial CM and large intraorbital component. The lesion was connected through a large basal vein to a cerebral intraventricular CM. Transconjunctival resection showed typical findings of CM. A complete histopathology and immunostaining analysis was performed and revealed a clear acute lymphomononuclear reaction with a predominant immune cellular inflammation. Conclusions A case of intraorbital and extracranial cavernomatous mass, connected to a cerebral intraventricular CM through a large basal vein, has presented with an aggressive course. A complete histopathologic and immunohistochemical analysis of the orbital mass has pictured a clear immune-cellular inflammatory reaction adding to the amounting evidence of association between inflammation and site aggressiveness in the setting of CMs.

Neurocysticercosis (NCC) is an endemic disease and important public health problem in some areas of the World and epilepsy is the most common neurological manifestation. Multiple intracranial lesions, commonly calcified, are seen on cranial computed tomography (CT) in the chronic phase of the disease and considered one of the diagnostic criteria of the diagnosis. Magnetic resonance imaging (MRI) is the test that better depicts the different stages of the intracranial cysts but does not show clearly calcified lesions. Cerebral cavernous malformations (CCM), also known as cerebral cavernomas, are frequent vascular malformations of the brain, better demonstrated by MRI and have also epilepsy as the main form of clinical presentation. When occurring in the familial form, cerebral cavernomas typically present with multiple lesions throughout the brain and, very often, with foci of calcifications in the lesions when submitted to the CT imaging. In the countries, and geographic areas, where NCC is established as an endemic health problem and neuroimaging screening is done by CT scan, it will be important to consider the differential diagnosis between the two diseases due to the differences in adequate management. RESUMO A neurocisticercose (NCC) é um importante problema endêmico de saúde pública em algumas áreas do mundo, sendo epilepsia sua manifestação clínica mais comum. Múltiplas lesões intracranianas, geralmente com calcificações visualizadas em tomografia computorizada de crânio, são interpretadas como um dos critérios diagnósticos na fase crônica da doença. A ressonância magnética é o melhor teste de imagem para identificar a doença em diferentes estágios de sua forma cística mas apresenta limitações para demonstrar lesões calcificadas. Malformações cavernosas cerebrais, ou cavernomas, são malformações vasculares comuns ao sistema nervoso e epilepsia é também a sua forma mais frequente de apresentação. Na sua forma familiar cavernomas apresentam-se tipicamente com múltiplas lesões encefálicas e, frequentemente, com focos de calcificações na TC. Em alguns países, e determinadas regiões geográficas, onde neurocisticercose é endêmica, a neuroimagem mais usada para diagnóstico é a TC de crânio. Nesse contexto torna-se importante estabelecer bases para o diagnóstico diferencial entre as duas doenças, devido às diferentes formas de acompanhamento e tratamento adequado.

Background Familial cerebral cavernous malformations (CCM) are among the most common vascular malformations of the central nervous system (CNS) and are linked to mutations on the specific genes CCM1/KRIT1, CCM2/MGC4607, and CCM3/PDCD10. We present the first report in the literature of a pharmaco-resistant epileptic patient harboring co-occurring pathogenic mutations within CCM2/MGC4607 and CCM1/KRIT1. Case Description A 51-year-old patient first presented at age of 33 years with episodes of seizures. Magnetic resonance imaging including a susceptibility-weighted imaging sequence had shown multiple cerebral cavernous malformation lesions. She had partial response of symptoms and remained in routine follow-up needing progressive pharmacological improvement. Direct sequencing allowed the detection of 1 nonsense pathogenic mutation in CCM2/MGC4607 (c.118C>T; p.Arg40Ter) and 1 unclassified frameshift insertion variant in CCM1/KRIT1 (c.1687_1688insT; p.Tyr563LeufsTer5). Conclusions Although the CCM2/MGC460 variant seems to be the major contributor for the patient’s CCM phenotype, the mutated CCM1/KRIT1 seems to act as a booster to CCM overall pathogenicity.

Background Cerebral cavernous malformations (CCMs) are vascular capillary anomalies with a dysfunctional endothelial adherent junction profile, depicting hemorrhage and epilepsy as the main clinical features. With the advent of an increasingly personalized medicine, better comprehension of genetic mechanisms behind CCM represents an important key in the management of the patients and risk rating in relatives. In this context, genetic factors that might influence clinical expressiveness of CCM need to be identified. Case Description A 33-year-old woman harboring multiple CCM lesions with a CCM1 mutational profile already being treated conservatively for a right mesial temporal lobe CCM presented with refractory seizures. Magnetic resonance imaging showed no bleeding in the lesion, and the patient was submitted to complete resection of the CCM. Histopathology of the CCM samples depicted an extensive inflammatory reaction and colocalization of CD20+ and CD68+ cells. Genetic analyses of the patient and her mother demonstrated a novel CCM1 (KRIT1) frameshift mutation (c.1661_1662insT; p.Leu554PhefsTer14). Furthermore, variants in CD14 (rs778588), TLR-4 (rs10759930), SOD2 (rs4880), APEX1 (rs1130409), and OGG1 (rs1052133), known as polymorphisms related to disease aggressiveness, were detected in the patient and not in her oligosymptomatic mother harboring the same CCM1 mutation. Conclusions Heterogeneity of clinical manifestations among individuals with familial CCM with the same genotype adds mechanistic involvement of modifier factors as phenotypic markers. We describe a novel CCM1/KRIT1 familial mutation in which the coexistence of genetic variants in inflammation and oxidative stress may be related to variable expressiveness of the disease.

Glioblastoma (GBM) is the most common and aggressive malignant primary brain tumor and still lacks effective therapeutic strategies. It has already been shown that old drugs like sulfasalazine (SAS) and valproic acid (VPA) present antitumoral activities in glioma cell lines. SAS has also been associated with a decrease of intracellular glutathione (GSH) levels through a potent inhibition of xc- glutamate/cystine exchanger leading to an antioxidant deprotection. In the same way, VPA was recently identified as a histone deacetylase (HDAT) inhibitor capable of activating tumor suppression genes. As both drugs are widely used in clinical practice and their profile of adverse effects is well known, the aim of our study was to investigate the effects of the combined treatment with SAS and VPA in GBM cell lines. We observed that both drugs were able to reduce cell viability in a dose-dependent manner and the combined treatment potentiated these effects. Combined treatment also increased cell death and inhibited proliferation of GBM cells, while having no effect on human and rat cultured astrocytes. Also, we observed high protein expression of the catalytic subunit of xc- in all the examined GBM cell lines, and treatment with SAS blocked its activity and decreased intracellular GSH levels. Noteworthy, SAS but not VPA was also able to reduce the [14C]-ascorbate uptake. Together, these data indicate that SAS and VPA exhibit a substantial effect on GBM cell’s death related to an intracellular oxidative response imbalance, making this combination of drugs a promising therapeutic strategy.

Background: Cerebral cavernous malformations (CCM) are clusters of dilated sinusoidal channels lined by a single layer of endothelium. In contradistinction to arteriovenous malformations, these lesions do not have smooth muscle or elastin in their lining and they are angiographically occult, and the MRI is the most sensitive test for CCM detection. CCM are one of the most prevalent vascular malformations of the central nervous system, affecting about 0.4-0.6% of the general population. The main complication of this malformation is the risk of bleeding, which may cause neurological deficits that affect the quality of life (QoL) in patients. When symtomatic, they may be surgically treated for relieving the mass effect and seizures refractory to drug uses, hemorrhage and drug-refractory epilepsy. Patient-reported outcome (PRO) may be a strategy that can be used to evaluate QoL of CCM population and was used in a sample of non-operated patients. Methods: An observational, cross-sectional analysis to evaluate the PRO using the SF-36 and EuroQol 5 dimensions (EQ-5D) questionnaires of QoL added to functional metrics using the Karnofsky Performance Status (KPS) in 49 patients not submitted to intervention and with long-term follow-up. Results: During the 364 person-years of follow-up, there was an average of individual follow-up of 7.42 years. The mean age was 46.8 years (18-84) - 57% of them were female, 71% had superficial lesions, and 65% had the familial form. Comparisons of SF-36 dimensions with KPS graded p = 0.04), vitality (p = 0.001), and general state of health (p = 0.03) domains. The domain mental health was worse in patients without surgical indication (p = 0.032). The functional capacity domain had the highest overall grading in the group. The EQ-5D dimensions of mobility (p = 0.03) and pain/discomfort (p = 0.001) were the ones with lower score compared to KPS Conclusion: The study is the first to evaluate, with validated tools, the PRO of non-operated CCM patients and has demonstrated in a selected group of patients that it was possible to achieve long-term clinical stability, thereby maintaining QoL and functional neurological outcome.

Astrocytes play a critical role in the development and homeostasis of the central nervous system (CNS). Astrocyte dysfunction results in several neurological and degenerative diseases. However, a major challenge to our understanding of astrocyte physiology and pathology is the restriction of studies to animal models, human post-mortem brain tissues, or samples obtained from invasive surgical procedures. Here, we report a protocol to generate human functional astrocytes from cerebral organoids derived from human pluripotent stem cells. The cellular isolation of cerebral organoids yielded cells that were morphologically and functionally like astrocytes. Immunolabelling and proteomic assays revealed that human organoid-derived astrocytes express the main astrocytic molecular markers, including glutamate transporters, specific enzymes and cytoskeletal proteins. We found that organoid-derived astrocytes strongly supported neuronal survival and neurite outgrowth and responded to ATP through transient calcium wave elevations, which are hallmarks of astrocyte physiology. Additionally, these astrocytes presented similar functional pathways to those isolated from adult human cortex by surgical procedures. This is the first study to provide proteomic and functional analyses of astrocytes isolated from human cerebral organoids. The isolation of these astrocytes holds great potential for the investigation of developmental and evolutionary features of the human brain and provides a useful approach to drug screening and neurodegenerative disease modelling.

The balance between excitatory and inhibitory synaptic inputs is critical for the control of brain function. Astrocytes play important role in the development and maintenance of neuronal circuitry. Whereas astrocytes-derived molecules involved in excitatory synapses are recognized, molecules and molecular mechanisms underlying astrocyte-induced inhibitory synapses remain unknown. Here, we identified transforming growth factor beta 1 (TGF-β1), derived from human and murine astrocytes, as regulator of inhibitory synapse in vitro and in vivo. Conditioned media derived from human and murine astrocytes induce inhibitory synapse formation in cerebral cortex neurons, an event inhibited by pharmacologic and genetic manipulation of the TGF-β pathway. TGF-β1-induction of inhibitory synapse depends on glutamatergic activity and activation of CaM kinase II, which thus induces localization and cluster formation of the synaptic adhesion protein, Neuroligin 2, in inhibitory postsynaptic terminals. Additionally, intraventricular injection of TGF-β1 enhanced inhibitory synapse number in the cerebral cortex. Our results identify TGF-β1/CaMKII pathway as a novel molecular mechanism underlying astrocyte control of inhibitory synapse formation. We propose here that the balance between excitatory and inhibitory inputs might be provided by astrocyte signals, at least partly achieved via TGF-β1 downstream pathways. Our work contributes to the understanding of the GABAergic synapse formation and may be of relevance to further the current knowledge on the mechanisms underlying the development of various neurological disorders, which commonly involve impairment of inhibitory synapse transmission.

Glioblastoma (GBM) is considered incurable due to its resistance to current cancer treatments. So far, all clinically available alternatives for treating GBM are limited, evoking the development of novel treatment strategies that can more effectively manage these tumors. Extensive effort is being dedicated to characterize the molecular basis of GBM resistance to chemotherapy and to explore novel therapeutic procedures that may improve overall survival. Cytolysins are toxins that form pores in target cell membranes, modifying ion homeostasis and leading to cell death. These pore-forming toxins might be used, therefore, to enhance the efficiency of conventional chemotherapeutic drugs, facilitating their entrance into the cell. In this study, we show that a non-cytotoxic concentration of equinatoxin II (EqTx-II), a pore-forming toxin from the sea anemone Actinia equina, potentiates the cytotoxicity induced by temozolomide (TMZ), a first-line GBM treatment, and by etoposide (VP-16), a second- or third-line GBM treatment. We also suggest that this effect is selective to GBM cells and occurs via PI3K/Akt pathway inhibition. Finally, Magnetic resonance imaging (MRI) revealed that a non-cytotoxic concentration of EqTx-II potentiates the VP-16-induced inhibition of GBM growth in vivo. These combined therapies constitute a new and potentially valuable tool for GBM treatment, leading to the requirement of lower concentrations of chemotherapeutic drugs and possibly reducing, therefore, the adverse effects of chemotherapy.

Defective brain hormonal signaling has been associated with Alzheimer's disease (AD), a disorder characterized by synapse and memory failure. Irisin is an exercise-induced myokine released on cleavage of the membrane-bound precursor protein fibronectin type III domain-containing protein 5 (FNDC5), also expressed in the hippocampus. Here we show that FNDC5/irisin levels are reduced in AD hippocampi and cerebrospinal fluid, and in experimental AD models. Knockdown of brain FNDC5/irisin impairs long-term potentiation and novel object recognition memory in mice. Conversely, boosting brain levels of FNDC5/irisin rescues synaptic plasticity and memory in AD mouse models. Peripheral overexpression of FNDC5/irisin rescues memory impairment, whereas blockade of either peripheral or brain FNDC5/irisin attenuates the neuroprotective actions of physical exercise on synaptic plasticity and memory in AD mice. By showing that FNDC5/irisin is an important mediator of the beneficial effects of exercise in AD models, our findings place FNDC5/irisin as a novel agent capable of opposing synapse failure and memory impairment in AD.

Background: Synapse formation and function is modulated by intrinsic and extrinsic non-autonomous factors. Results: Astrocytes induce synapse formation through TGF-β1 pathway. TGF-β1 synaptogenic property is dependent on d-serine signaling. Conclusion: TGF-β induces excitatory glutamatergic synapses in vertebrates. Significance: This is a novel molecular mechanism that might impact synaptic function and shed light on new potential therapeutic targets for synaptic deficit diseases., Assembly of synapses requires proper coordination between pre- and postsynaptic elements. Identification of cellular and molecular events in synapse formation and maintenance is a key step to understand human perception, learning, memory, and cognition. A key role for astrocytes in synapse formation and function has been proposed. Here, we show that transforming growth factor β (TGF-β) signaling is a novel synaptogenic pathway for cortical neurons induced by murine and human astrocytes. By combining gain and loss of function approaches, we show that TGF-β1 induces the formation of functional synapses in mice. Further, TGF-β1-induced synaptogenesis involves neuronal activity and secretion of the co-agonist of the NMDA receptor, d-serine. Manipulation of d-serine signaling, by either genetic or pharmacological inhibition, prevented the TGF-β1 synaptogenic effect. Our data show a novel molecular mechanism that might impact synaptic function and emphasize the evolutionary aspect of the synaptogenic property of astrocytes, thus shedding light on new potential therapeutic targets for synaptic deficit diseases.

Spinal vascular malformations are uncommon lesions, and controversy persists regarding optimal investigation, classification, and treatment strategies. The authors report on a patient with a spinal root arteriovenous malformation (AVM) associated with a parenchymal cavernous malformation (CM) in the same spinal cord segment and describe a complete familial and molecular investigation. This 35-year-old woman presented with symptoms of progressive clinical spastic paraparesis. Magnetic resonance imaging results were suggestive of a spinal cord cavernoma associated with cerebral CMs. Her family history included 2 sisters treated for epilepsy. At surgery an intraspinal root AVM was found at the same level of the cord CM, and both lesions were completely removed. Cerebral gradient echo MR imaging disclosed multiple cavernomas in her relatives, which prompted the molecular diagnosis. On sequence analysis, a novel mutation on the cerebral CM1 (CCM1) gene (c796insA) was found. The authors report on a unique case of familial cerebral CM in which a spinal root AVM was situated next to a cord CM, and discuss the concomitant occurrence of altered nervous system angiogenesis and vasculogenesis.

The harmonious development of the central nervous system depends on the interactions of the neuronal and glial cells. Extracellular matrix elements play important roles in these interactions, especially laminin produced by astrocytes, which has been shown to be a good substrate for neuron growth and axonal guidance. Glioblastomas are the most common subtypes of primary brain tumors and may be astrocytes in origin. As normal laminin-producing glial cells are the preferential substrate for neurons, and glial tumors have been shown to produce laminin, we questioned whether glioblastoma retained the same normal glial–neuron interactive properties with respect to neuronal growth and differentiation. Then, rat neurons were co-cultured onto rat normal astrocytes or onto three human glioblastoma cell lines obtained from neurosurgery. The co-culture confirmed that human glioblastoma cells as well as astrocytes maintained the ability to support neuritogenesis, but non-neural normal or tumoral cells failed to do so. However, glioblastoma cells did not distinguish embryonic from post-natal neurons in relation to neurite pattern in the co-cultures, as normal astrocytes did. Further, the laminin organization on both normal and tumoral glial cells was altered from a filamentous arrangement to a mixed punctuate/filamentous pattern when in co-culture with neurons. Together, these results suggest that glioblastoma cells could identify neuronal cells as partners, to support their growth and induce complex neurites, but they lost the normal glia property to distinguish neuronal age. In addition, our results show for the first time that neurons modulate the organization of astrocytes and glioblastoma laminin on the extracellular matrix.

In the treatment of complex paraclinoidal and giant cavernous aneurysms, preservation of the patency of the internal carotid artery (ICA) is not always possible, and therapeutic occlusion of the carotid is still an important option for their management. A complete preoperative evaluation of the carotid reserve circulation, including the use of temporary balloon occlusion test and single photon emission computerized tomography (SPECT) should be included in the current paradigms of paraclinoidal and intracavernous aneurysms management. We present a series of fifteen patients with sixteen giant or complex carotid cavernous or ophthalmic aneurysms that were treated following a protocol for our preoperative decision-making analysis. Extracranial to intracranial saphenous vein bypass was reserved to the cases where carotid occlusion would be associated with high risk of ischemic complications and was performed in three patients. Besides the difficulties in dealing with those complex aneurysms, good clinical outcome was possible in our experience with the designed paradigm. No tratamento de aneurismas paraclinoideos complexos e cavernosos gigantes, a preservação da patência vascular nem sempre é possível, e a oclusão terapêutica da carótida ainda é uma opção importante no seu manejo. Uma avaliação pré-operatória completa da reserva circulatória carotídea, incluindo o uso do teste de oclusão temporária por balão associado à tomografia computadorizada por emissão de fóton único (SPECT) podem ser de grande utilidade para definir a opção terapêutica a ser adotada. Nós apresentamos uma série de quinze pacientes com dezesseis aneurismas complexos ou gigantes do segmento oftálmico e cavernoso da artéria carótida, que foram tratados de acordo com determinado protocolo de investigação pré-operatória. Anastomose com enxerto de veia safena entre a carótida extra e intracraniana foi reservada para os casos em que a oclusão carotídea estaria associada a um alto risco de complicações isquêmicas e foi realizado em três pacientes. Apesar das dificuldades em lidar com aneurismas complexos como os aqui relatados, é possível obter um bom resultado clínico nestes pacientes com o paradigma desenhado.

Background Fifty-one patients with cervical spondylotic myelopathy (CSM) treated by anterior cervical corpectomy with fusion (ACWF) at our institution were included in a study during a period of 10 years to evaluate neurological, anatomical, and functional outcomes including satisfaction levels. Methods We have completed a prospective evaluation of 39 patients with spondylotic myelopathy submitted to ACWF during the period of 1989-2000. The data were analyzed for age, duration of symptoms, severity of preoperative neurological deficit, and single-level or multilevel compressive status looking for possible association with prognostic surrogate data and clinical outcome that were evaluated with the Nurick score and a survey of level of satisfaction. Results Of the 51 patients, 39 fullfilled the intended follow-up being 28 men (71.8%) and 11 women (28.2%). The average age was 63.5 years. Duration of symptoms ranged from 1 to 240 months (mean, 38.1 months). The mean preoperative Nurick scale score was 2.97; the mean postoperative score was 2.1. The most frequently involved vertebral body was C5 (71.7%). The follow-up period was longer than 18 months for all patients. Postoperative nonneurological complications occurred in 8 patients (15.6%). The mortality rate was 1.9% (n = 1). Postoperative results showed improvement in 25 patients (64.1%), no change in 13 (33.3%), and worsening in 1 (2.6%). The correlation coefficient of preoperative and postoperative Nurick scores was 0.733 (R2 = 0.53). Of the 39 patients, 31 answered the questionnaire for quality of life—19 (61.2%) were very satisfied, 6 were satisfied (19.35%), and 6 were not satisfied (19.35%). Conclusion Most patients (80.6%) were very satisfied or satisfied with the outcome and would decide again for the surgery (87%) if the results were previously known. Anterior cervical corpectomy with fusion was a reliable and rewarding procedure for CSM, with functional improvement in most patients. Excellent long-term outcome results in cervical fusion can be achieved without the use of hardware instrumentation.

INTRODUÇÃO: Mais de 90% dos resultados citológicos per-operatórios neurocirúrgicos correlacionam-se com o histopatológico. Porém, a sua real necessidade é por vezes questionada. OBJETIVO: Avaliar a necessidade do exame per-operatório tendo-se em vista a conduta neurocirúrgica imediata. MATERIAL E MÉTODOS: Revimos 130 casos de exames per-operatórios solicitados de um total de 293 procedimentos cirúrgicos para tratamento de lesões expansivas do sistema nervoso central (SNC), extra ou intra-axiais, sendo 46 biópsias estereotáxicas e 84 cirurgias abertas, realizados de 1998 a 2001. Foram realizados esfregaços, o diagnóstico foi comparado com o histopatológico, e os neurocirurgiões, questionados sobre a implicação do resultado do exame na conduta, caso a caso. RESULTADOS: O exame per-operatório foi solicitado em 44,4% do total de cirurgias, tendo sido considerado relevante para a conduta em 84% destes casos ou, nas biópsias, para avaliar a representatividade do material, o que corresponde a 37,2% do total de cirurgias realizadas no período. Excluindo-se as biópsias estereotáxicas, com indicação inquestionável, o exame foi necessário em 75%, sendo considerado desnecessário, sobretudo nas lesões extra-axiais, em geral solicitado por curiosidade do cirurgião. CONCLUSÃO: Apesar de ser um exame com acurácia demonstrada, a realização de exames per-operatórios sem utilidade para a conduta neurocirúrgica pode vir a sobrecarregar patologistas em tarefas desnecessárias. Nossos resultados demonstraram que o exame foi necessário na grande maioria dos casos, mesmo após a exclusão das biópsias estereotáxicas, sobretudo nas lesões intra-axiais, auxiliando na avaliação da demanda desses exames, por vezes excessiva, apesar de útil para treinamento e ensino.

uptured intracranial aneurysms are not an uncommon cause of severe neurologic damage and death. RecurR rent rupture and vasospasm are, by far, the leading causes of worsening prognosis for the survivors. Delayed ischemic neurologic deficit (DIND), caused by narrowing of cerebral vessels following subarachnoid hemorrhage (SAH), continues to burden patients as a major cause of morbidity and mortality. Angiographic vasospasm occurs in 30% 70% of the cases after SAH, rendering 30% of the patients with symptomatic DIND. Symptoms develop gradually and may fluctuate. In the awake patient, vasospasm development may include new or increasing headache, declining of consciousness, and, depending on the anatomic regions of decreased perfusion, hemiparesis, aphasia, abulia, and other focal signs.

Diversos fatores têm sido associados ao desenvolvimento de edema peritumoral nos meningiomas. Foram estudados os aspectos radiológicos e anátomo-patológicos de 51 meningiomas intracranianos operados no Hospital Universitário Clementino Fraga Filho (HUCFF). Dois terços dos meningiomas apresentavam edema perilesional. O tamanho dos meningiomas correlacionou-se com a presença de edema, sendo mais frequente nos meningiomas grandes (>4cm). A localização parece, também, influenciar no desenvolvimento do edema peritumoral, sendo mais acentuado nos meningiomas da asa do esfenóide e incomum nos meningiomas do tubérculo selar. Os subtipos histológicos de meningioma não se correlacionaram com a intensidade do edema peritumoral. Dos diversos mediadores químicos descritos na literatura recente relacionados ao desenvolvimento de edema peritumoral em tumores intracranianos, destaca-se o fator de crescimento do endotélio vascular (VEGF). A expressão nos meningiomas do VEGF e de seu receptor flk-1 foi estudada com técnica imuno-histoquímica, demonstrando a sua expressão nas células tumorais.

Pituitary tuberculomas are extremely rare lesions, with only few cases described in the literature, usually mistaken as pituitary tumors. Its heterogeneous clinical and imaging profile preclude preoperative diagnosis which ultimately relies on the histopathological examination. We describe a 46 years old woman who presented with an episode of confusion and hypopituitarism with no evidence of systemic tuberculosis. Computed tomography (CT) showed a central calcified and enhancing sellar mass. Magnetic resonance imaging (MRI) showed a sellar mass with suprasellar extension and associated optic chiasm compression. She was submitted a craniotomy for biopsy and resection. A caseous material was found at the center of the lesion involved by a thick wall. Due to the wall adherence to the optic chiasm and the inflammatory aspects of the lesion, subtotal removal was achieved and the patient followed on anti-tuberculous and hormonal replacement therapy. Sellar tuberculomas should be considered in the differential diagnosis of sellar tumors in order to offer appropriate treatment.

Background Glioblastoma (GBM) is the most common primary brain tumor and the most aggressive glial tumor. This tumor is highly heterogeneous, angiogenic, and insensitive to radio- and chemotherapy. Here we have investigated the progression of GBM produced by the injection of human GBM cells into the brain parenchyma of immunocompetent mice. Methods Xenotransplanted animals were submitted to magnetic resonance imaging (MRI) and histopathological analyses. Results Our data show that two weeks after injection, the produced tumor presents histopathological characteristics recommended by World Health Organization for the diagnosis of GBM in humans. The tumor was able to produce reactive gliosis in the adjacent parenchyma, angiogenesis, an intense recruitment of macrophage and microglial cells, and presence of necrosis regions. Besides, MRI showed that tumor mass had enhanced contrast, suggesting a blood–brain barrier disruption. Conclusions This study demonstrated that the xenografted tumor in mouse brain parenchyma develops in a very similar manner to those found in patients affected by GBM and can be used to better understand the biology of GBM as well as testing potential therapies. Electronic supplementary material The online version of this article (doi:10.1186/1471-2407-14-923) contains supplementary material, which is available to authorized users.

The balance between excitatory and inhibitory synaptic inputs is critical for the control of brain function. Astrocytes play important role in the development and maintenance of neuronal circuitry. Whereas astrocytes-derived molecules involved in excitatory synapses are recognized, molecules and molecular mechanisms underlying astrocyte-induced inhibitory synapses remain unknown. Here, we identified transforming growth factor beta 1 (TGF-β1), derived from human and murine astrocytes, as regulator of inhibitory synapse in vitro and in vivo. Conditioned media derived from human and murine astrocytes induce inhibitory synapse formation in cerebral cortex neurons, an event inhibited by pharmacologic and genetic manipulation of the TGF-β pathway. TGF-β1-induction of inhibitory synapse depends on glutamatergic activity and activation of CaM kinase II, which thus induces localization and cluster formation of the synaptic adhesion protein, Neuroligin 2, in inhibitory postsynaptic terminals. Additionally, intraventricular injection of TGF-β1 enhanced inhibitory synapse number in the cerebral cortex. Our results identify TGF-β1/CaMKII pathway as a novel molecular mechanism underlying astrocyte control of inhibitory synapse formation. We propose here that the balance between excitatory and inhibitory inputs might be provided by astrocyte signals, at least partly achieved via TGF-β1 downstream pathways. Our work contributes to the understanding of the GABAergic synapse formation and may be of relevance to further the current knowledge on the mechanisms underlying the development of various neurological disorders, which commonly involve impairment of inhibitory synapse transmission.

Epilepsy affects approximately 0.8% of the world population and is most common among those with chronic neurological diseases1. Some patients are refractory to antiepileptic drugs and they develop refractory epilepsy2. This kind of epilepsy presents a higher frequency of sudden death3; surgical treatment is indicated and has shown significantly higher efficacy compared to antiepileptic drug treatment4 […] Isolation of neurosphere-like bodies from an adult patient with refractory temporal lobe epilepsy

Department of Radiology.Received 27 April 2009, received in final form 14 July 2009. Accepted 6 August 2009.Dr. Jorge Marcondes de Souza – Department of Neurosurgery / Hospital Universitario Clementino Fraga Fillho - Av. Rodolpho Rocco 250 - 21941-902 Rio de Janeiro RJ - Brasil. E-mail address: jmarcondes@hucff.ufrj.br

Juvenile myoclonic epilepsy (JME) with praxis-induced seizures consists of a complex group of generalized epileptic syndromes. The aim of the present study was identifying the association between self-perception trigger factors and myoclonic jerks. Twenty-two patients were submitted to a protocol of neuropsychological activation (NPA) during video-electroencephalography (video-EEG) methods for 4-6 hours. A questionnaire was applied regarding patients' self-perception of factors that precipitate of seizures comparing with the video-EEG findings. Stress and sleep deprivation were perceived as triggers by 81.82%, followed by mental concentration (36.36%) and manual activities (31.82%). Praxis-induced seizures occurred in 36.4% of these patients. Self-perception of stress (81.82%), flashing lights (22.73%) and reading (13.64%) as triggering factors was significantly associated with triggering myoclonic seizures during video-EEG. We conclude that main finding of this study is the strong correlation between self-perception of trigger factors and actual trigger factors for seizures.

Epilepsy and syncope are clinical conditions with high prevalence rates in the general population, and the differential diagnosis between them is difficult. Objective To assess the frequency of syncope in patients diagnosed with drug-resistant epilepsy (DRE) without apparent heart disease, to investigate the relationship between clinical and electroencephalographic (EEG) changes, and to verify the role of the inclination test (IT). Method An open, prospective study from 2004 to 2006, including 35 consecutive patients from the Epilepsy Program of Hospital Universitário Clementino Fraga Filho who were diagnosed with DRE without apparent heart disease. Results The frequency of syncope was 25.7% (n=9), with a significant prevalence in women. Vasovagal syncope (VVS) was the most frequent diagnosis. Conclusion We found a significant association between syncope and the presence of autonomic symptoms (p=0.005). The IT plays an important role in the differential diagnosis of patients with DRE presenting with autonomic symptoms, regardless of EEG results and brain magnetic resonance imaging (MRI) abnormalities. Epilepsia e síncope são condições clínicas com alta prevalência na população geral e, às vezes, o diagnóstico diferencial entre elas é difícil. Objetivo Investigar a frequência de síncope em pacientes diagnosticados com epilepsia fármaco resistente (EFR), sem doença cardíaca aparente; investigar a relação entre alterações clínicas e eletrencefalográficas; verificar o papel do teste de inclinação (TI). Método Estudo aberto prospectivo, realizado de 2004 a 2006, incluindo 35 pacientes consecutivos do Programa de Epilepsias do Hospital Universitário Clementino Fraga Filho, diagnosticados com EFR, sem doença cardíaca aparente. Resultados A frequência de síncope foi de 25,7% (n=9), com prevalência significativa em mulheres. Síncope vasovagal (SVV) foi o diagnóstico mais frequente. Conclusão Encontramos uma significativa associação entre síncope e a presença de sintomas autonômicos (p=0,005). O TI tem importante papel no diagnóstico diferencial de pacientes com diagnóstico de EFR que apresentam sintomas autonômicos, a despeito de alterações eletrencefalográficas e de ressonância magnética do crânio.

Inflammation influences the pathogenesis of seizures by boosting neuronal degeneration of temporal lobe epilepsy with hippocampal sclerosis (TLE-HS). This work aimed to determine the activity of metalloproteases (MMPs) in brain tissue fragments of TLE-HS patients and the effect of lobectomy on circulating inflammatory biomarkers. Surgical fragments (n=4) from epileptogenic focus (EF) e perilesion area (PL), and control hippocampus from autopsy (n=5) were processed for glial protein (GFAP), activated microglia (IB4) immunohistochemistry, and metalloprotease activity (MMP-2, -9). Perilesional area showed GFAP positive cells with morphology of activate astrocyte and reactive gliosis nearby the lesion. In the lesion foci, astrocytes had altered cytoarchitecture with disorganized stroma suggestive of necrosis, and numerous mononuclear cells with few projections and morphological characteristics of activate microglia. Analysis of MMP-9 and MMP-2 in the sera before and after hippocampectomy confirmed the inflammatory pattern of TLE-HS, with high MMP-9 activity; high MMP-9/TIMP-1 and urokinase uPAR plasma levels before lobectomy but low after surgery. Maintenance of MMP-2 activity indicates persistent tissue remodeling in both groups. The present work shows that patients with chronic and medically intractable TLE-HS that undergone amigdalo-hippocampectomy for removal of epileptogenic lesion had a clinical enduring benefit of lack seizure recurrence for up to a year, and consistent reduction of proteases (MMP-9 and uPAR) activation that participate as important inflammatory epileptogenic inducers.

Aneurysms arising at the proximal intracranial carotid artery (between cavernous sinus and posterior communicating artery) and at the anterior communicating complex may present with technical difficulties regarding appropriate access without excessive brain retraction. In a series of 15 patients the authors show the use of the cranio-orbital approach, formerly designed in the access of skull base tumors, for these subgroups of aneurysms. They discuss the advantages of a basal avenue in minimizing brain retraction, better anatomical orientation, obviation of tissue ressection and easier extra-dural bone removal. It was not identified any complication due to the described approach. Aneurismas situados junto à artéria carótida intracraniana proximal (entre seio cavernoso e artéria comunicante posterior) e ao nível do complexo comunicante anterior podem apresentar dificuldades técnicas relacionadas ao acesso apropriado sem retração cerebral excessiva. Em uma série de 15 pacientes os autores mostram o uso do acesso crânio-orbital, utilizado inicialmente para abordagem a tumores da base do crânio, para esses subgrupos de aneurismas. Discutem suas vantagens em minimizar retração, melhor orientação anatômica, evitar ressecção de tecido neural e facilitar remoção óssea. Não foi identificada qualquer complicação devida ao acesso descrito.