De novo intracranial aneurysm formation in SARS-CoV-2 infection: first report of a yet unknown complication

BACKGROUND AND IMPORTANCE

COVID-19 is a viral infection that mainly affects the respiratory tract, but can also cause multiple inflammatory reactions, including neurological and cerebrovascular manifestations. We report the case of a COVID-19 patient who developed 'de novo' multiple cerebral aneurysms with no risk factors for aneurysm formation.

CLINICAL PRESENTATION

A 55-year-old man with SARS-CoV-2 infection came to our attention for left eye blindness accompanied by ptosis, palpebral chemosis and retro-orbital pain. Brain CT and CT-angiography were negative for hemorrhages and for vascular malformations. Repeated intracerebral hemorrhages and neurological deterioration then occurred, and a new CT-angiography showed multiple intracranial aneurysms that were not present before.

CONCLUSION

Intracranial aneurysm formation as a complication of COVID-19 has not been previously reported. As other viral infections do, COVID-19 may be able to determine a vascular damage that can ultimately lead to development of an aneurysm. It is reasonable to hypothesize an involvement of the renin-angiotensin system as a pathogenic mechanism. A conservative therapy aiming at inflammatory modulation and vascular damage prevention may be warranted in these patients.

Deep learning-based algorithm for postoperative glioblastoma MRI segmentation: a promising new tool for tumor burden assessment

OBJECTIVE

Clinical and surgical decisions for glioblastoma patients depend on a tumor imaging-based evaluation. Artificial Intelligence (AI) can be applied to magnetic resonance imaging (MRI) assessment to support clinical practice, surgery planning and prognostic predictions. In a real-world context, the current obstacles for AI are low-quality imaging and postoperative reliability. The aim of this study is to train an automatic algorithm for glioblastoma segmentation on a clinical MRI dataset and to obtain reliable results both pre- and post-operatively.

METHODS

The dataset used for this study comprises 237 (71 preoperative and 166 postoperative) MRIs from 71 patients affected by a histologically confirmed Grade IV Glioma. The implemented U-Net architecture was trained by transfer learning to perform the segmentation task on postoperative MRIs. The training was carried out first on BraTS2021 dataset for preoperative segmentation. Performance is evaluated using DICE score (DS) and Hausdorff 95% (H95).

RESULTS

In preoperative scenario, overall DS is 91.09 (± 0.60) and H95 is 8.35 (± 1.12), considering tumor core, enhancing tumor and whole tumor (ET and edema). In postoperative context, overall DS is 72.31 (± 2.88) and H95 is 23.43 (± 7.24), considering resection cavity (RC), gross tumor volume (GTV) and whole tumor (WT). Remarkably, the RC segmentation obtained a mean DS of 63.52 (± 8.90) in postoperative MRIs.

CONCLUSIONS

The performances achieved by the algorithm are consistent with previous literature for both pre-operative and post-operative glioblastoma's MRI evaluation. Through the proposed algorithm, it is possible to reduce the impact of low-quality images and missing sequences.

Stem-like signatures in human meningioma cells are under the control of CXCL11/CXCL12 chemokine activity

BACKGROUND

Meningiomas are mainly benign brain tumors, although about 20% of histologically benign cases are clinically aggressive and recur after resection. We hypothesize that meningioma brain invasiveness and recurrence may be related to the presence of cancer stem cells and their high responsiveness to the CXCL12-CXCR4/CXCR7 chemokine axis. The aim of this study was to isolate meningioma stem cells from human samples, characterize them for biological features related to malignant behavior, and to identify the role of CXCR4/CXCR7 in these processes.

METHODS

Meningioma stem cells were isolated from patient-derived primary cultures in stem cell-permissive conditions, and characterized for phenotype, self-renewal, proliferation and migration rates, vasculogenic mimicry (VM), and in vivo tumorigenesis, in comparison with differentiated meningioma cells and stem-like cells isolated from normal meninges. These cell populations were challenged with CXCL12 and CXCL11 and receptor antagonists to define the chemokine role in stem cell-related functions.

RESULTS

Stem-like cells isolated from meningioma cultures display higher proliferation and migration rates, and VM, as compared to meningioma non-stem cells or cells isolated from normal meninges and were the only tumorigenic population in vivo. In meningioma cells, these stem-like functions were under the control of the CXCR4/CXCR7 chemokine axis.

CONCLUSIONS

We report a role for CXCL11 and CXCL12 in the control of malignant features in stem-like cells isolated from human meningioma, providing a possible basis for the aggressive clinical behavior observed in subsets of these tumors. CXCR4/CXCR7 antagonists might represent a useful approach for meningioma at high risk of recurrence and malignant progression.

To use or not to use antithrombotics in unruptured cerebrovascular malformations? A systematic review focusing on this clinical and surgical dilemma

OBJECTIVE

Antithrombotic medications (ATMs), including antiplatelet therapy (APT) and oral anticoagulants (OACs), are widely used in current clinical practice for the prevention and treatment of a variety of cardiovascular diseases, deep vein thrombosis, and pulmonary thromboembolisms. The long-term usage of these drugs, associated with an inherent risk of bleeding, raises concerns for unruptured cerebrovascular malformations (UCVMs), such as arteriovenous malformations (AVMs), cerebral cavernous malformations (CCMs), and intracranial aneurysms (IAs), in which the bleeding risk also poses a major threat. The aim of this study was to assess the safety and risk-benefit ratio of ATMs in these various neurosurgical diseases and to give neurosurgeons a safe and reasonable choice regarding whether to administer ATMs to these patients during the course of the disease.

METHODS

The authors conducted a systematic review of the literature (PubMed/MEDLINE and Embase) according to Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines, which yielded 4 papers about CCMs, 2 about AVMs, and 9 about IAs. The risk of bias was assessed using the Cochrane Collaboration's tool.

RESULTS

For AVMs, only 2 studies with a total of only 14 patients were included. Data on AVMs and ATMs are limited and weak, relying on small case series. Nevertheless, there is no evidence for either an increased risk of intracranial hemorrhage in patients with AVMs who are receiving ATMS or the need to interrupt ATMs in those patients who have been diagnosed with sporadic, unruptured brain AVMs. With respect to CCMs, the literature search resulted in 4 cohort studies and 1 meta-analysis. These studies affirmed the absence of a correlation between ATMs and an increased risk of CCM bleeding while simultaneously suggesting a protective role of ATMs against bleeding. Concerning IAs, the topic is more complex and debated, despite larger case series on IAs than on AVMs or CCMs. The benefits of ATMs for IAs may vary according to the type of intervention and specific drug administered. Evidence supports the continuation of long-term APT for all patients newly diagnosed with an IA, whereas starting APT in patients with incidentally discovered IA as a means of prophylaxis against rupture is unclear.

CONCLUSIONS

The findings of this review should be taken as a wide overview of UCVM and ATM. Future research should consider the relationship of AVM, CCM, and IA with APT and OAC independently.

Long-term functional recovery in C5-C6 avulsions treated with distal nerve transfers

BACKGROUND

In patients suffering from traction lesions of the brachial plexus, complete C5 and/or C6 root avulsion patients with C7 root preservation are relatively uncommon occurrences, but represent excellent candidates for surgical treatment, with satisfactory results. Shoulder abduction and extra-rotation, elbow flexion and forearm supination are lost functions restorable with surgical treatment.

METHODS

This single-center, prospective observational study involved a series of 27 young adults with C5 and/or C6 root complete avulsion and C7 preservation, which underwent surgical repair with double or triple nerve transfer.

RESULTS

Patients recovered a useful elbow flexion. Electromyographic and clinical signs of biceps reinnervation were observed in each UN-MC nerve transfer. The abduction strength recovery was M5 in 10 patients, M4 in 14 patients and M3 in 3 patients. The external rotation strength recovery was M5 in 4 patients, M4 in 18 patients, M3 in 3 patients and M2 in 2 patients. The elbow flection strength was M5 in 5 patients, M4 in 15 patients and M3 in 7 patients. Elbow extension was preserved in all cases.

CONCLUSIONS

The concept of 'peripheral rewiring procedures' represents an advance in the repair of the peripheral nerve injuries. Triple nerve transfer can be nowadays considered a standard treatment for isolated C5-C6 avulsions. We report our experience with the second-biggest casuistry in the literature on patients treated with this technique. We consider our outcome concerning functional recovery to be satisfying and comparable to data reported in the literature.

Useful outcome measures in INPH patients evaluation

Introduction

Idiopathic normal pressure hydrocephalus (INPH) is a neurological disorder that is potentially reversible and clinically characterized by a specific triad of symptoms, including gait disturbance, cognitive disorders, and urinary incontinence. In INPH assessment, the most commonly used test is the Timed Up and Go test (TUG), but a more comprehensive assessment would be necessary. The first aim of the present study is to verify the sensitivity of a protocol with both clinical and instrumental outcome measures for gait and balance in recognizing INPH patients. The second aim is to verify the most important spatio-temporal parameters in INPH assessment and their possible correlations with clinical outcome measures.

Methods

Between January 2019 and June 2022, we evaluated 70 INPH subjects. We assessed balance performances with the Berg Balance Scale (BBS), Short Physical Performance Battery (SPPB), and TUG, both single (ST) and dual task (DT). We also performed an instrumental gait assessment with the GAITRite electronic walkway system, asking the patients to walk on the carpet for one minute at normal speed, fast speed, and while performing a dual task. We compared the results with those of 20 age-matched healthy subjects (HS).

Results

INPH patients obtained statistically significant lower scores at the BBS, SPPB, and TUG DT but not at the TUG ST, likely because the DT involves cognitive factors altered in these subjects. Concerning instrumental gait evaluation, we found significant differences between HS and INPH patients in almost all spatio-temporal parameters except cadence, which is considered a relevant factor in INPH guidelines. We also found significant correlations between balance outcome measures and gait parameters.

Discussion

Our results confirm the usefulness of BBS and suggest improving the assessment with SPPB. Although the TUG ST is the most commonly used test in the literature to evaluate INPH performances, it does not identify INPH; the TUG DT, instead, might be more useful. The GAITRite system is recognized as a quick and reliable tool to assess walking abilities and spatio-temporal parameters in INPH patients, and the most useful parameters are stride length, stride width, speed, and the percentage of double support. Both clinical and instrumental evaluation may be useful in recognizing subjects at risk for falls.

A Novel Patient-Personalized Nanovector Based on Homotypic Recognition and Magnetic Hyperthermia for an Efficient Treatment of Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is the deadliest brain tumor, characterized by an extreme genotypic and phenotypic variability, besides a high infiltrative property in healthy tissues. Apart from very invasive surgical procedures, to date, there are no effective treatments, and life expectancy is very limited. In this work, we propose an innovative therapeutic approach based on lipid-based magnetic nanovectors, owning a dual therapeutic function: chemotherapy, thanks to an antineoplastic drug (regorafenib) loaded in the core, and localised magnetic hyperthermia, thanks to the presence of iron oxide nanoparticles, remotely activated by an alternating magnetic field. The drug has been selected based on ad hoc patient-specific screenings; moreover, the nanovector is decorated with cell membranes derived from patients' cells, aiming at increasing homotypic and personalized targeting. We demonstrated that this functionalization not only enhances the selectivity of the nanovectors towards patient-derived GBM cells, but also their blood-brain barrier in vitro crossing ability. The localised magnetic hyperthermia induces both thermal and oxidative intracellular stress, that lead to lysosomal membrane permeabilization and release of proteolytic enzymes into the cytosol. Collected results show that hyperthermia and chemotherapy work in synergy to reduce GBM cell invasion properties, to induce intracellular damage and, eventually, to prompt cellular death. This article is protected by copyright. All rights reserved.

Radiofrequency Ablation in Vertebral Body Metastasis with and without Percutaneous Cement Augmentation: A Systematic Review Addressing the Need for SPINE Stability Evaluation

Vertebral body metastases (VBM) are one of the most frequent sites of bone metastasis, and their adequate therapeutic management still represents an insidious challenge for both oncologists and surgeons. A possible alternative treatment for VBM is radiofrequency ablation (RFA), a percutaneous technique in which an alternating current is delivered to the tumor lesion producing local heating and consequent necrosis. However, RFA alone could alter the biomechanics and microanatomy of the vertebral body, thus increasing the risk of post-procedure vertebral fractures and spine instability, and indeed the aim of the present study is to investigate the effects of RFA on spine stability. A systematic review according to PRISMA-P guidelines was performed, and 17 papers were selected for the systematic review. The results show how RFA is an effective, safe, and feasible alternative to conventional radiotherapy for the treatment of VBM without indication for surgery, but spine stability is a major issue in this context. Although exerting undeniable benefits on pain control and local tumor recurrence, RFA alone increases the risk of spine instability and consequent vertebral body fractures and collapses. Concomitant safe and feasible therapeutic strategies such as percutaneous vertebroplasty and kyphoplasty have shown synergic positive effects on back pain and improvement in spine stability.

Transient meningism in children after non-autologous duraplasty for Chiari Malformation surgery: A case series

BACKGROUND

Increasing the posterior fossa volume is the mainstay of treatment for Chiari type 1 Malformation (C1M) and type 1.5 (C1.5M). Different options to restore CSF flow have been described but no consensus has been reached yet. Bony decompression of posterior cranial fossa with dural opening provides good results but at the price of complications such as pseudomeningocele and aseptic meningitis. A single center retrospective analysis was conducted to find any relationships between outcome and perioperative factors. As a second goal a specific analysis was conducted on the complications and their hypothetical causes.

METHODS

All the pediatric patients who underwent to posterior fossa bony decompression and dural opening for C1M or C1.5M in the period 2008-2020 were included in the study. A minimum period of three-months follow-up was considered among the inclusion criteria.

RESULTS

A population of fifty-three consecutive patients was collected. Pseudomeningocele and a mild meningeal irritation resulted the most frequent complications. Considering preoperative and intraoperative factors, the type of dural graft showed a relatively strong correlation (P<.01) with pseudomeningocele appearance and the development of meningism. In the latter case, a short course of steroids was the only treatment required to control symptoms.

CONCLUSIONS

Different factors could influence the outcome in Chiari Malformation surgery and eventually the development of complications. An adequate dural graft selection is of paramount importance when a dural opening for posterior fossa augmentation is planned. In case of mild meningeal irritation, a trial with short course steroids could avoid revision surgery.

Practical Algorithm for the management of multisutural craniosynostosis with associated Chiari malformation and/or hydrocephalus

The association between multisutural craniosynostosis with Chiari malformation (CM), venous hypertension and hydrocephalus is widely described in the literature, especially in children with pediatric craniofacial syndromes. Some efforts have been done in the last years to understand the complex pathogenetic mechanisms underlying this association and several theories have been proposed. However, whatever the pathophysiological mechanism, it is still unclear what is the best management and treatment of CM and hydrocephalus in multisutural craniosynostosis patients. The aim of this study is to report our twenty-five years'experience in treating pediatric patients affected by these rare pathologies, in order to propose a simple and effective therapeutic flow-chart for their management. We collected data of each patient that underwent a cranial vault remodelling for a complex craniosynostosis in our institution in the last 25 years. We recorded data concerning type of craniosynostosis and craniofacial syndromes, presence of ventriculomegaly and Chiari Malformation (CM) at presentation and clinical and radiological follow-up. Therefore, we evaluated the final outcomes (improved, stable, deteriorated) of these patients and created a practical flow-chart that could help physicians to choose the best surgical treatment when different pathological conditions, as CM I or hydrocephalus, affect complex craniosynostosis children. Despite the proposed algorithm comes from a clinical experience on 85% successfully treated patients with multiple craniosynostosis, more extensive and deep studies are needed to better understand CM and hydrocephalus development in such conditions.

Oligodendroglioma with ganglioglioma-like maturation: the histopathological diagnostic challenge of a brain neoplasm with aberrant neuronal component - A case report and review of the literature

Background

Oligodendroglioma with ganglioglioma-like maturation is a rare entity not included in the 2016 World Health Organization Classification of Tumors of the Central Nervous System. To date, only a few cases were described in the literature. We report a case of this tumor, along with a review of the previous case reports/ series.

Case Description

A 63-year-old man with a left frontal mass and a 2-month history of seizures underwent surgical resection in our center. Grossly, the specimen appeared as a yellowish mass with prominent hemorrhagic component. Microscopically, the lesion was composed by small round cells often surrounded by a clear halo and, near the hemorrhagic area, by scattered large cuboidal cells with vesicular nuclei and prominent eosinophilic nucleoli. On immunohistochemical stains, both cells components tested positive for ATRX, p53, and GFAP; larger ganglion-like cells showed synaptophysin and chromogranin-A expression. IDH1 codon 132 mutation, 1p-19q-codeletion, and MGMT methylation were observed. Eventually, a diagnosis of oligodendroglioma (the WHO grade II) with ganglioglioma-like maturation was rendered. The patient received adjuvant chemotherapy and is currently alive and asymptomatic.

Conclusion

Recognition of ganglioglioma-like maturation in oligodendrogliomas may prevent undertreatment of these neoplasms. To this end, fluorescence in situ hybridization assays are crucial for defining the 1p-19q status.

P03.11.A Potential role of pre-radiotherapy MRI for target delineation in high-grade gliomas: a multicenter retro-prospective cohort study

Background

The optimal timing for target identification in high-grade glioma (HGG) remains unclear due to variability in the hyper-signal T2/FLAIR between MRI performed at diagnosis, post-surgery and at radiotherapy (RT) start. The aim of this study was to retrospectively confirm that RT planned on delayed MRI might allow to spare more normal tissue without decreasing local tumour control, in order to prospectively evaluate the best standard and advanced MRI and metabolic imaging sequences for clinical tumor volume (CTV) adaptation.

Material and Methods

We analyzed a retrospective cohort of consecutive patients with HGG treated from 2017 to 2020. All patients had a diagnostic MRI and another performed immediately post-surgery or pre-RT. Target volumes were contoured, based on T2/FLAIR, on diagnostic and post-surgery MRI in group A, while in group B on pre-RT MRI. We analyzed GTV and CTV volume, and the percentage increase between them. Moreover, we compared the two groups in terms of clinical-pathological characteristics and progression-free survival (PFS) and overall survival (OS). A prospective study, started on January 2022, has enrolled patients with HGG evaluated by advanced sequences MRI at diagnosis, post-surgery and pre-RT. In addition, some selected patients have undergone diagnostic DOPA-PET and pre-RT DOPA-PET. 2 MRI-guided contours have been performed for each patient: adapted on T2/FLAIR post-surgery and CTV-adapt on pre-RT, to assess study objectives.

Results

In retrospective cohort we analyzed 54 patients (25 group A, 29 group B). The median age of patients was 61 years (IQR 17,75), 93% had an ECOG PS of 0 or 1, 51 were symptomatic at diagnosis. Patients in group B had more frequently MGMT methylation (59 % vs. 28%, p=0.01) while less frequently frontal lobe involvement (60% vs. 24%, p=0.01). The median percentage increase between GTV and CTV was higher in group A than B: 431% (range 62%-7335%) vs 385% (range 53%-3174%), respectively. No significant difference in the pattern of relapse was observed, since &gt;90% of disease recurrences were in-field in both groups. Median PFS and OS of the overall population were 9.5 months (95% CI 7 - 12) and 18.5 months (95% CI 16 - 24), respectively. Patients in group B had a significant better PFS as compared to those in group A (p=0.03), but similar OS. Nevertheless, imbalance in MTMT methylation status between the two groups was a major driver for PFS. Overall, 37 out of 51 patients had improvement in neurological symptoms (p&lt;0.001), with no difference between the two groups (p=0.54).

Conclusion

Our data suggest that CTV adaptation to pre-RT T2/FLAIR may allow reducing RT volume, without affecting symptoms relieving and disease control. Results from the prospective study will help identifying the best adaptation of CTV guided by T2/FLAIR, advanced MRI sequences and metabolic imaging, in order to optimize efficacy and safety of treatment planning.

Peculiar bony involvement of sinus pericranii in children: Extensive diploic erosion in three "karstic" variants

OBJECT

Sinus pericranii (SP) is a rare, benign, extradural venous anomaly whose extracranial connection consists in an enlarged subgaleal drainage composed of a network of thin-walled veins that form a varix on the external table of the skull. In the present series of three patients we present three variantesof SP which have never been described, characterized by an extensive diploic erosion causing a "karstic" effect.

METHODS

A systematic review was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. A comprehensive search for relevant articles was performed on PubMed from 1992 to 2022 using the following search words: "sinus pericranii".

RESULTS

The search produced 77 articles with 137 patients. In all the cases analysed, there were not reported any patients with extensive diploic erosion, namely "karstic" variants. So, the authors present clinical history, neuroimages, treatment strategies and outcome of 3 patients with a "karstic" SP with the aim to describe this clinicradiological entity.

CONCLUSIONS

In this study, our group identified a peculiar variant of SP characterized by bony involvement with extensive diploic "karstic" erosion of diploe, with possible tendency to enlarge during time.

Mind the gap: IgG4-related disease mimicking infectious cerebral mass lesions

Background

Cerebral intraparenchymal masses represent usually a neoplastic, or infectious differential diagnostic workup in neurology or infectious disease units.

Case presentation

Our patient was an 82-year-old male presenting with seizures, cerebral masses and a history of past treated pulmonary tuberculosis. Initial workup included a differential diagnosis of an infectious mass/multiple abscess. After exclusion of infectious or primary neoplastic origins by negative HIV serology, the absence of immune suppression, endocarditic lesions, negative results of blood cultures and bronchoalveolar lavage, negative cerebrospinal fluid workout on spinal tap led to exclusion of infectious causes. A surgical procedure was performed to access one of the lesions. This yielded a firm, cyst-like mass of histiocytic granulomatous tissue with a conspicuous plasmacellular component and a relevant IgG4 plasmacellular component consistent with IgG4-related disease.

Steroid treatment determined conspicuous improvement and led to discharge of the patient.

Conclusion

Parenchymal IgG4-related disease may be included as a new entity in the differential diagnosis of single or multiple cerebral masses in addition to infectious or neoplastic etiology.

Discrimination of glioma patient-derived cells from healthy astrocytes by exploiting Raman spectroscopy

Glioblastoma multiforme (GBM) is one of the most common and aggressive brain tumors. It presents a very bad prognosis with a patients' overall survival of 12-15 months; treatment failure is mainly ascribable to tumor recurrence. The development of new tools, that could help the precise detection of the tumor border, is thus an urgent need. During the last decades, different vibrational spectroscopy techniques have been developed to distinguish cancer tissue from heathy tissue; in the present work, we compared GBM cells deriving from four patients with healthy human astrocytes using Raman spectroscopy. We have shown that the region between 1000 and 1300 cm^-1 is enough informative for this discrimination, indeed highlighting that peaks related to DNA/RNA and cytochrome c are increased in cancer cells. Finally, our model has been able to discriminate cancer cells from healthy cells with an average accuracy of 92.5%. We believe that this study might help to further understand which are the essential Raman peaks exploitable in the detection of cancer cells, with important perspectives under a diagnostic point of view.

Chloride intracellular channel 1 activity is not required for glioblastoma development but its inhibition dictates glioma stem cell responsivity to novel biguanide derivatives

Background

Chloride intracellular channel-1 (CLIC1) activity controls glioblastoma proliferation. Metformin exerts antitumor effects in glioblastoma stem cells (GSCs) inhibiting CLIC1 activity, but its low potency hampers its translation in clinical settings.

Methods

We synthesized a small library of novel biguanide-based compounds that were tested as antiproliferative agents for GSCs derived from human glioblastomas, in vitro using 2D and 3D cultures and in vivo in the zebrafish model. Compounds were compared to metformin for both potency and efficacy in the inhibition of GSC proliferation in vitro (MTT, Trypan blue exclusion assays, and EdU labeling) and in vivo (zebrafish model), migration (Boyden chamber assay), invasiveness (Matrigel invasion assay), self-renewal (spherogenesis assay), and CLIC1 activity (electrophysiology recordings), as well as for the absence of off-target toxicity (effects on normal stem cells and toxicity for zebrafish and chick embryos).

Results

We identified Q48 and Q54 as two novel CLIC1 blockers, characterized by higher antiproliferative potency than metformin in vitro, in both GSC 2D cultures and 3D spheroids. Q48 and Q54 also impaired GSC self-renewal, migration and invasion, and displayed low systemic in vivo toxicity. Q54 reduced in vivo proliferation of GSCs xenotransplanted in zebrafish hindbrain. Target specificity was confirmed by recombinant CLIC1 binding experiments using microscale thermophoresis approach. Finally, we characterized GSCs from GBMs spontaneously expressing low CLIC1 protein, demonstrating their ability to grow in vivo and to retain stem-like phenotype and functional features in vitro. In these GSCs, Q48 and Q54 displayed reduced potency and efficacy as antiproliferative agents as compared to high CLIC1-expressing tumors. However, in 3D cultures, metformin and Q48 (but not Q54) inhibited proliferation, which was dependent on the inhibition dihydrofolate reductase activity.

Conclusions

These data highlight that, while CLIC1 is dispensable for the development of a subset of glioblastomas, it acts as a booster of proliferation in the majority of these tumors and its functional expression is required for biguanide antitumor class-effects. In particular, the biguanide-based derivatives Q48 and Q54, represent the leads to develop novel compounds endowed with better pharmacological profiles than metformin, to act as CLIC1-blockers for the treatment of CLIC1-expressing glioblastomas, in a precision medicine approach.

Lymphoplasmacyte-rich meningioma with hematologic signs and PD-L1 over-expression

Lymphoplasmacyte-rich meningioma (LPRM) is one of the rarest variants of grade I meningiomas. It can be clinically associated with prominent peripheral blood abnormalities, anemia, and/or various gammopathy, which usually disappear after surgical removal of the tumor. We document a case of right frontal LPRM in a 72-year-old male who presented general cognitive decadence. The patient suffered from mild anemia. The LPRM is a rare variant of meningioma, with only a few cases globally reported in the literature. It has been categorized as a grade I tumor in the 2021 World Health Organization (WHO) classification central nervous system. Due to the rarity, this meningioma variant origin and biological behavior are still not clear. Immunohistochemistry profile showed prominent PD-L1 expression, leading to additional interrogation on LPRM immunomorphological characteristics, the significance of the inflammatory tumoral microenvironment and its correlation with the immune-checkpoints.

Anticoagulant therapy in high grade gliomas: a systematic review on state of the art and future perspectives

INTRODUCTION

Anticoagulation management in high-grade gliomas is a widely studied but still debated topic, since the increased thrombotic risk is accompanied by the high background rate of intralesional bleeding. Currently, the main challenge when prescribing anticoagulants to HGG patients is to balance the risk between ICH and VTE both in the peri-operative period and in the post-operative follow up during adjuvant chemo and radiotherapic treatment.

EVIDENCE ACQUISITION

A systematic review according to PRISMA-P guidelines was performed: 12 observational studies were selected, eight retrospective and four prospective Regarding the reviews, 3 were selected, two of which analyzed bleeding complications of anticoagulation therapy and one on thrombotic events.

EVIDENCE SYNTHESIS

In the selected studies, the risk of VTEs was between 4 and 33%, while in patients with VTEs subsequently subjected to anticoagulant therapy the cases of ICH ranged from 0% to 15.4%. Regarding the reviews, two meta-analysis have evaluated the incidence of ICH in patients undergoing anticoagulation therapy following thromboembolic events, they agree in quantifying the increased risk of bleeding.

CONCLUSIONS

The results of our review are generally consistent in stating that the thrombotic risk is increased in patients with HGG, suggesting that more extensive antithrombotic prophylaxis could positively impact the outcome of these patients, even if currently there are no conclusive elements in indicating or contraindicating prolonged antithrombotic prophylaxis considering that anticoagulant administration in these patients involves an increased risk of ICH. All the studies examined have considered a prolonged heparin treatment without considering the new oral anticoagulants, so further studies about this topic is needed.

Ipsilateral Nasoseptal Flap Pedicle for Transpterygoid Approach: Technical Note

INTRODUCTION

Transpterygoid approach is an expanded endonasal approach (EEA) that allows surgical access to the medial infratemporal fossa, to the skull base area of petrous bone and to the Meckel's cave. During this approach, a sacrifice of sphenopalatine artery is often required, leading to the need of contralateral Hadad-Bassagasteguy flap (HBF) or alternative reconstructive techniques.

MATERIALS AND METHODS

We report a case of spontaneous CSF leak due to a meningo-encephalocele in the left lateral recess of sphenoid sinus, in which an ispilateral nasoseptal flap was harvest and sphenopalatine artery was preserved.

RESULTS

We described the surgical technique adopted to preserve the ipsilateral nasoseptal vascular pedicle during transpterygoid approach and we performed a review of the pertinent literature.

CONCLUSION

Wide exposure of the pterygoid base through transpterygoid approach could be obtained preserving the sphenopalatine artery, allowing skull base reconstruction with ipsilateral nasoseptal flap.

P16.13 MenImmune: Evaluation of immune-related and prognostic biomarkers in meningioma

BACKGROUND

Meningiomas are the most common group of adult central nervous system primary tumor. The major known predictors for meningioma recurrence are extent of surgical resection and histological grade. Although grading system is the actual standard for risk classification, there are several exceptions in the clinical behavior. Recent studies have shown that meningiomas can express PD-L1, a known therapeutic target for checkpoint inhibitors. Tumor microenvironment and hormonal setting are known to influence the immune system response. The only standard therapeutic strategies nowadays are surgery and radiotherapy. Meningiomas microenvironment needs to be further studied looking for new therapeutic targets. New prognostic tools combining histological and radiological features (RF) are needed to better address the treatment strategy.

ELIGIBILITY CRITERIA

Patients diagnosed with meningioma who underwent surgery at the Department of Neurosurgery of the IRCCS Ospedale Policlinico San Martino of Genoa from 1998. - Availability of magnetic resonance imaging (MRI) at diagnosis. - Availability of histological samples.

OBJECTIVES

Identification and prevalence of immune-related biomarkers and their correlation with morphological and hormonal features. - Survival analyses in the study population and according to the different characteristics analyzed. - The identification of specific clinical, histological and RF of meningiomas and their inclusion in a prognostic signature.

STUDY DESIGN

This is a retrospective-prospective monocentric study designed to analyze clinical, radiological and histological features of meningioma patients. - Clinical data will be collected from the electronic patient records. - Analyses will be conducted on a cohort of patients enriched with higher grade meningioma to balance the proportion between high and low grade histologies. - Histological specimen will be blindly reviewed and reclassified according to histological type, morphological features and WHO 2016 criteria. - The MRI features will be analyzed at diagnosis.

STUDY ANALYSIS

We retrospectively enrolled 50 patients with available radiological, histological and clinical data.- All histopathological specimens will be examined with slides obtained from material fixed in 10% neutral buffered formalin, included in kerosene, sectioned at 3 µm and stained with hematoxylin-eosin. - We will look for the presence of estrogens and progesterone receptors. - Concerning immune-related biomarkers we will further assess PD-L1 positivity (cut-off: positive 1%, negative &lt;1%), MSI status and the inflammatory infiltrate with immunohistochemistry, in particular TILs (CD45, CD3, CD4, CD8, FOXP3, CTLA4), B cell (CD20), TAM (CD68). - All histological and radiological data will be analyzed and correlated with the clinical characteristics of meningioma patients and their outcomes.

P13.22 Menglia: an innovative approach to liquid biopsies in glioma patients

BACKGROUND

Gliomas are the second most frequent primary brain tumor. Since 2016 gliomas are classified according to histological, and molecular features such as IDH status and 1p19q codeletion. Recently oncological research has focused on liquid biopsies to reduce the need for invasive diagnostic tests. Cerebrospinal fluid (CSF) is the principal source of brain tumor biomarkers. Modern technologies currently allow us to analyze proteomic and metabolomic tumor profiles, in order to find new biomarkers without being constrained by a priori hypothesis. Several data from the literature also suggests that inflammatory cells and cytokines in tumors contribute to tumor growth, progression and immunosuppression. The possibility of simultaneously testing different inflammatory molecules on the biological fluids could lead to the identification of new biological markers with prognostic and predictive value for treatment response.

STUDY OBJECTIVES

- Identification of protein and/or lipid biomarkers specific to the glioma subgroup among those under analysis. - Identification of tumor group- and subgroup-specific CSF and/or serum inflammatory biomarkers among those tested. - Correlation of biomarkers with Progression Free Survival (PFS), Overall Survival (OS).

ELIGIBILITY CRITERIA

- Patients with a radiological suspected diagnosis of glioma eligible for surgery. - Age ≥ 18 years. - Availability of histological samples, CSF, blood and urine. - Patients with unconfirmed histological diagnosis of glioma will be excluded. - Patients who have never received any systemic or local treatment for CNS diseases.

STUDY DESIGN

This is a prospective monocentric study involving mass spectrometry analysis for characterization of proteins and metabolites and ELISA analysis for the characterization of different cytokines in parallel anonymized biological samples consisting of tumor tissue, CSF, blood and urine from glioma patients, divided into three different molecular subtypes: 1p19q codelet/IDH mutated, 1p19q non-codelet/IDH mutated and 1p19q non-codelet/IDH wt. Biological samples will be taken at surgery, at 24–48 h after surgery and every 3 months up to 1 year. The control group will include patients with subarachnoid hemorrhage or hydrocephalus, either undergoing external ventricular shunting or undergoing ventricular catheter placement/revision surgery.

STUDY ANALYSIS

Data interpretation will be based on a statistical analysis of the data, applying tools such as Principal Component Analysis (PCA) Weighted Correlation Network Analysis (WGNCA), Multiple Venn Diagram, T-Test, ANOVA, Clustering and Gene Ontology Enrichment, non-parametric Mann-Whitney test. For the assessment of clinical outcome, survival curves will be compared between different groups of patients who share a similar protein/metabolomic/inflammatory profile.

The positive effects of surgery on symptomatic stereotactic radiation-induced peritumoral brain edema: A report of three cases

Background

Peritumoral brain edema is an uncommon but life-threatening side effect of brain tumors radiosurgery. Medical therapy usually alleviates symptoms until edema spontaneously disappears. However, when peritumoral brain edema endangers the patient's life or medical therapy fails to guarantee an acceptable quality of life, surgery might be considered.

Case Description

Our report focuses on three patients who developed extensive peritumoral brain edema after radiosurgery. Two were affected by vestibular schwannomas and one by a skull-base meningioma. Peritumoral brain edema worsened despite maximal medical therapy in all cases; therefore, surgical removal of the radiated lesion was carried out. In the first patient, surgery was overdue and resulted in a fatal outcome. On the other hand, in the latter two cases surgery was quickly effective. In all three cases, an unmanageable brain swelling was not found at surgery.

Conclusion

Surgical removal of brain tumors previously treated with radiosurgery was safe and effective in resolving shortly peritumoral brain edema. This solution should be considered in patients who do not respond to medical therapy and before worsening of clinical conditions. Interestingly, the expected brain swelling was not confirmed intraoperatively. In our experience, this magnetic resonance finding should not be considered a criterion to delay surgery.

Management of spinal aneurysms associated with arteriovenous malformations: systematic literature review and illustrative case

PURPOSE

Spinal aneurysms are rare vascular malformations, commonly associated with spinal AVMs. AVM-associated spinal aneurysms are burdened by significant morbidity. The purpose of our study is to evaluate the best treatment strategy for these uncommon vascular lesions and to report an illustrative case.

METHODS

We reviewed clinical and radiological data of a patient surgically treated at our institution for a spinal AVM with an associated prenidal aneurysm. According to PRISMA guidelines, a systematic literature review has been performed in order to discuss the best management AVM-associated prenidal aneurysms.

RESULTS

In the reported case, the aneurysm showed spontaneous regression at follow-up after surgical removal of the AVM. Only 6 articles reported management of spinal prenidal AVM-associated aneurysms. Basing on our experience and data from literature, surgical treatment of the aneurysm may be indicated along with the resection of the AVM if the aneurysm is close to the nidus. Conversely, if the aneurysm is far away from the nidus or in an unfavorable position, resection of the nidus only may lead to aneurysm regression as in the reported case.

CONCLUSIONS

The treatment strategy for AVM-associated spinal aneurysms should be tailored on the single patient. In presence of large aneurysms that cause mass-effect symptoms, when rupture of the aneurysm is suspected or when treatment of the AVM is not proposable, direct treatment of the aneurysm should be considered. Otherwise, when complete resection of the nidus is performed, the eventually associated unruptured aneurysms located in challenging positions can be safely managed conservatively.

How do you manage ANTICOagulant therapy in neurosurgery? The ANTICO survey of the Italian Society of Neurosurgery (SINCH)

BACKGROUND

Anticoagulant assumption is a concern in neurosurgical patient that implies a delicate balance between the risk of thromboembolism versus the risk of peri- and postoperative hemorrhage.

METHODS

We performed a survey among 129 different neurosurgical departments in Italy to evaluate practice patterns regarding the management of neurosurgical patients taking anticoagulant drugs. Furthermore, we reviewed the available literature, with the aim of providing a comprehensive but practical summary of current recommendations.

RESULTS

Our survey revealed that there is a lack of knowledge, mostly regarding the indication and the strategies of anticoagulant reversal in neurosurgical clinical practice. This may be due a lack of national and international guidelines for the care of anticoagulated neurosurgical patients, along with the fact that coagulation and hemostasis are not simple topics for a neurosurgeon.

CONCLUSIONS

To overcome this issue, establishment of hospital-wide policy concerning management of anticoagulated patients and developed in an interdisciplinary manner are strongly recommended.

Ultra-short antibiotic prophylaxis guided by preoperative microbiological nasal swabs in endoscopic endonasal skull base surgery

PURPOSE

Endoscopic endonasal skull base surgery (EESBS) is a clean-contaminated procedure. Guidelines regarding the antibiotic prophylaxis in EESBS have not been developed yet, and today, there are no universally accepted protocols. In this article, we investigated the efficacy of our new ultra-short antibiotic prophylaxis protocol for EESBS guided by the cultural results of preoperative microbiological nasal swabs.

METHODS

We defined as "nasal swab-related antibiotic protocol" the administration of a first-generation cephalosporin (cefazolin 2 g) in patients whose nasal swabs revealed the presence of normal nasal flora or methicillin-sensitive Staphylococcus aureus (MSSA), and the administration of vancomycin 1 g intravenously in patients whose nasal swabs revealed the presence of methicillin-resistant Staphylococcus aureus (MRSA) or with reported cephalosporin/penicillin allergy. This case-control study included 120 patients who underwent EESBS. The case group included 60 cases who received the "nasal swab-related antibiotic protocol," while the control group included 60 cases who received the "standard hospital antibiotic protocol" used in neurosurgery (cefazolin 2 g plus metronidazole 500 mg at induction, and 2 g of cefazolin repeated after 180 min).

RESULTS

The preoperative microbiological nasal swabs showed normal nasal flora in 42 patients (70%), MSSA in 17 patients (28.3%), and MRSA in 1 patient (1.6%). During the study period, no cases of meningitis or sinusitis occurred in the case group ("nasal swab-related antibiotic protocol"), while two infections (3.3%, 1 sinusitis and 1 meningitis) were reported in the control group ("standard hospital antibiotic protocol"). Mean length of hospitalization was 6.5 days for the case group and 8.5 days in the control group. "Standard hospital antibiotic protocol" is less expensive (range, 2.88-5.42 euros) compared with our new "nasal swab-related antibiotic protocol" (range, 10.02-32.56 euros), but in line with other antibiotic prophylaxis protocols reported in literature.

DISCUSSION

The low complication rates of our case series (0%) is comparable to complication rates reported in literature (1.6% for meningitis and 8% for sinusitis). Compared with other perioperative antibiotic regimens reported in literature, the "nasal swab-related antibiotic protocol" is cheap and at least equally effective. We discuss the rationale on which we based the choice of chemoprophylaxis, the timing, and the length of our regimen.

CONCLUSIONS

Our study confirmed the safety and efficacy of our easily applicable and low-cost antibiotic prophylaxis protocol.

Turning tables: a war-like approach to neurosurgical emergencies in the Covid-19

BACKGROUND

During the Coronavirus-disease-2019 (COVID-19) pandemic emergency, neurosurgeons may have to decide to prioritize treatments to patients with the best chance of survival, as in a war setting triage. We discuss factors that should be taken into account in the perioperative period and neurocritical care management of neurosurgical patients during a pandemic emergency; in particular, we will focus on the decision on whether to operate or not a patient during the COVID-19 pandemic and where and how to provide neurointensive care treatment.

METHODS

A multidisciplinary expert panel composed by specialists with direct experience in COVID-19 management discussed and reviewed the criteria that should be taken into account in the decision to operate or not a patient during the COVID-19 pandemic.

RESULTS

Disease-related factors should be first taken into account in order to precisely know the enemy we are facing. Patient-related factors should be then evaluated to understand the battleground on which we are facing the enemy. After these considerations, we must ascertain costs and expected outcomes of our surgical intervention by evaluation of surgery-related factors. Finally, the last factor that need to be evaluated before surgery is the availability of resources, staff and ward availability for perioperative care in particular. All these considerations will lead to the optimal organization and management of neurosurgical emergencies during pandemic times, taking into account the community and not only the single patient.

CONCLUSIONS

We provided schematic preoperative considerations that we hope will help neurosurgeons to guide their decisions in these challenging times.

Incidence of hemorrhagic cerebrovascular disease due to vascular malformations during the COVID-19 national quarantine in Italy

BACKGROUND

hemorrhagic cerebrovascular disease due to vascular malformations represents an emergency for neurosurgery and neuro-interventional departments. During the COVID-19 pandemic, a dramatic reduction in the number of hospitalizations for acute myocardial infarction or stroke and a larger time interval from symptom onset to first medical contact have been reported. This study aims to verify the hypothesis that there would also have been a reduction of admissions for hemorrhagic cerebrovascular disease during the Italian lockdown.

MATERIAL AND METHOD

s A multicenter, observational survey was conducted to collect data on hospital admissions for hemorrhagic cerebrovascular disease due to vascular malformations throughout two-months (March 15th to May 15th); the years 2020 (COVID-19 Italian lockdown), 2019 and 2018 were compared. Cases were identified by ICD-9 codes 430, 431, 432.1, 432.9, 747.81 of each hospital database. The statistical significance of the difference between the event rate of one year versus the others was evaluated using Poisson Means test, assuming a constant population.

RESULTS

During the 2020 lockdown, the total number of admissions for hemorrhagic cerebrovascular disease was 92 compared with 116 in 2019 and 95 in 2018. This difference was not significant. GCS upon admission was 3-8 in 44 % of cases in 2020 (41 patients), 39.7 % in 2019 (46 patients) and 28 % in 2018 (27 patients).

CONCLUSION

Reduction of admissions for hemorrhagic cerebrovascular disease due to vascular malformations during the COVID-19 lockdown was not confirmed. Nevertheless, some patients reached the emergency rooms only several days after symptoms onset, resulting in a worse clinical condition at admission.

Coexisting Retrocerebellar Arachnoid Cyst and Chiari Type 1 Malformation: 3 Pediatric Cases of Surgical Management Tailored to the Pathogenic Mechanism and Systematic Review of the Literature

INTRODUCTION

Arachnoid cysts are benign cerebrospinal fluid collection within a duplication of arachnoid membrane and, when found in the retrocerebellar site, they may be associated with tonsils herniation. This rare situation of coexisting retrocerebellar arachnoid cyst (AC) and Chiari malformation type 1 (CM-1) have been previously reported in few cases (10 patients) with syringomyelia and hydrocephalus described to be the most relevant issues. The aim of this paper is to describe 3 pediatric cases of this condition with a systematic review of the literature, underlining the importance of surgical management tailored to the pathogenic mechanism.

METHODS

A restrospective analysis of patients treated for coexisting CM-1 and ACs at the authors' institution has been carried out.

RESULTS

A case of a 10-month-old baby with coexisting AC and CM-1 with tri-ventricular hydrocephalus treated with endoscopic third ventriculostomy, a case of a 1-year-old child with a huge retrocerebellar AC and CM-1 treated with a cysto-peritoneal shunt, and a case of a 15-year-old child with retrocerebellar AC causing symptomatic CM-1 treated with C0-C2 decompression, AC fenestration and duraplasty are described. A long-term follow-up is reported.

CONCLUSIONS

Surgical management of coexisting ACs and CM-1 should not aim at the complete resolution of the cyst or of tonsil herniation, especially when pediatric patients are treated. Rather, the purpose of the neurosurgeon should be to understand the underlying pathogenic mechanism, and then restoring both the cerebrospinal fluid flow in the posterior fossa and the dynamic equilibrium between ventricles, cyst, and subarachnoid space.

Escalate and De-Escalate Therapies for Intracranial Pressure Control in Traumatic Brain Injury

Severe traumatic brain injury (TBI) is frequently associated with an elevation of intracranial pressure (ICP), followed by cerebral perfusion pressure (CPP) reduction. Invasive monitoring of ICP is recommended to guide a step-by-step “staircase approach” which aims to normalize ICP values and reduce the risks of secondary damage. However, if such monitoring is not available clinical examination and radiological criteria should be used. A major concern is how to taper the therapies employed for ICP control. The aim of this manuscript is to review the criteria for escalating and withdrawing therapies in TBI patients. Each step of the staircase approach carries a risk of adverse effects related to the duration of treatment. Tapering of barbiturates should start once ICP control has been achieved for at least 24 h, although a period of 2–12 days is often required. Administration of hyperosmolar fluids should be avoided if ICP is normal. Sedation should be reduced after at least 24 h of controlled ICP to allow neurological examination. Removal of invasive ICP monitoring is suggested after 72 h of normal ICP. For patients who have undergone surgical decompression, cranioplasty represents the final step, and an earlier cranioplasty (15–90 days after decompression) seems to reduce the rate of infection, seizures, and hydrocephalus.

Escalation therapy in severe traumatic brain injury: how long is intracranial pressure monitoring necessary?

Traumatic brain injury frequently causes an elevation of intracranial pressure (ICP) that could lead to reduction of cerebral perfusion pressure and cause brain ischemia. Invasive ICP monitoring is recommended by international guidelines, in order to reduce the incidence of secondary brain injury; although rare, the complications related to ICP probes could be dependent on the duration of monitoring. The aim of this manuscript is to clarify the appropriate timing for removal and management of invasive ICP monitoring, in order to reduce the risk of related complications and guarantee adequate cerebral autoregulatory control. There is no universal consensus concerning the duration of invasive ICP monitoring and its related complications, although the pertinent literature seems to show that the longer is the monitoring maintenance, the higher is the risk of technical issues. Besides, upon 72 h of normal ICP values or less than 72 h if the first computed tomography scan is normal (none or minimal signs of injury) and the neurological exam is available (allowing to observe variations and possible occurrence of new-onset pathological response), the removal of invasive ICP monitoring can be justified. The availability of non-invasive monitoring systems should be considered to follow up patients' clinical course after invasive ICP probe removal or for substituting the invasive monitoring in case of contraindication to its placement. Recently, optic nerve sheath diameter and straight sinus systolic flow velocity evaluation through ultrasound methods showed a good correlation with ICP values, demonstrating their potential role in place of invasive monitoring or in the early weaning phase from the invasive ICP monitoring.

Spontaneous rupture of middle fossa arachnoid cysts: surgical series from a single center pediatric hospital and literature review

PURPOSE

Arachnoid cysts may present with symptoms deriving from cyst rupture, usually causing intracystic hemorrhage and subdural hematoma or hygroma. Rupture is usually caused by minor trauma, spontaneous rupture is an exceptional event, and 57 cases have been described in literature. We here present and discuss the largest series of spontaneously ruptured middle fossa arachnoid cysts in order to investigate clinical presentation and best treatment available.

METHODS

We report a retrospective series of 17 pediatric patients surgically treated for middle fossa arachnoid cyst with signs of cyst rupture without a history of trauma in the previous 90 days. We describe clinical presentation, treatment, and outcome at follow-up discussing our results with a literature review including all reported cases of spontaneous rupture of middle fossa arachnoid cysts.

RESULTS

In our experience patients most frequently presented with subdural hygroma, in literature, a chronic hematoma was most frequently reported. Headache is the most reported symptom at presentation. Neurological deficits and consciousness alterations are rare. Surgical treatment may resolve brain compression only or reduce rupture recurrence risk. Conservative treatment has also been proposed. Different treatments are reported and discussed focusing on indications, contraindications, risks, and expected benefits.

CONCLUSION

We propose, when safely possible, microsurgical cyst fenestration in skull base cisterns as the treatment of choice for these patients as long as it addresses both immediate decompression and risk of rupture recurrence. We report good outcomes and low incidence of complications from our series with a mean postoperative follow-up of 30 months.

Limits and pitfalls of indirect revascularization in moyamoya disease and syndrome

Moyamoya vasculopathy is a rare chronic cerebrovascular disorder characterized by the stenosis of the terminal branches of the internal carotid arteries and the proximal tracts of anterior and middle cerebral arteries. Although surgical revascularization does not significantly change the underlying pathogenic mechanisms, it plays a pivotal role in the management of affected individuals, allowing to decrease the risk of ischemic and hemorrhagic complications. Surgical approaches may be direct (extracranial-intracranial bypass), indirect, or a combination of the two. Several indirect techniques classifiable according to the tissue (muscle, periosteum, galea, dura mater, and extracranial tissues) or vessel (artery) used as a source of blood supply are currently available. In this study, we reviewed the pertinent literature and analyzed the advantages, disadvantages, and pitfalls of the most relevant indirect revascularization techniques. We discussed the technical aspects and the therapeutical implications of each procedure, providing a current state-of-the-art overview on the limits and pitfalls of indirect revascularization in the treatment of moyamoya vasculopathy.

Neurological Manifestations of Severe SARS-CoV-2 Infection: Potential Mechanisms and Implications of Individualized Mechanical Ventilation Settings

In December 2019, an outbreak of illness caused by a novel coronavirus (2019-nCoV, subsequently renamed SARS-CoV-2) was reported in Wuhan, China. Coronavirus disease 2019 (COVID-19) quickly spread worldwide to become a pandemic. Typical manifestations of COVID-19 include fever, dry cough, fatigue, and respiratory distress. In addition, both the central and peripheral nervous system can be affected by SARS-CoV-2 infection. These neurological changes may be caused by viral neurotropism, by a hyperinflammatory and hypercoagulative state, or even by mechanical ventilation-associated impairment. Hypoxia, endothelial cell damage, and the different impacts of different ventilatory strategies may all lead to increased stress and strain, potentially exacerbating the inflammatory response and leading to a complex interaction between the lungs and the brain. To date, no studies have taken into consideration the possible secondary effect of mechanical ventilation on brain recovery and outcomes. The aim of our review is to provide an updated overview of the potential pathogenic mechanisms of neurological manifestations in COVID-19, discuss the physiological issues related to brain-lung interactions, and propose strategies for optimization of respiratory support in critically ill patients with SARS-CoV-2 pneumonia.