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BACKGROUND: Scarce data are available regarding rebleeding predictors in poor-grade aneurysmal subarachnoid hemorrhage (aSAH). OBJECTIVES: To investigate predictors and clinical impact of rebleeding in a national multicentric poor-grade aSAH. METHODS: Retrospective analysis of prospectively collected data from the multicentric Poor Grade Aneurysmal Subarachnoid Hemorrhage Study Group (POGASH) registry of consecutive patients treated from January 1, 2015, to June 30th, 2021. Grading was defined as pretreatment World Federation of Neurological Surgeons grading scale IV-V. Ultra-early vasospasm (UEV) was defined as luminal narrowing of intracranial arteries not due to intrinsic disease. Rebleeding was defined as clinical deterioration with evidence of increased hemorrhage on subsequent computed tomography scans, fresh blood from the external ventricular drain, or deterioration before neuroradiological evaluation. Outcome was assessed by the modified Rankin Scale. RESULTS: Among 443 consecutive World Federation of Neurological Surgeons grades IV-V patients with aSAH treated within a median of 5 (IQR 4-9) hours since onset, rebleeding occurred in 78 (17.6%). UEV (adjusted odds ratio [OR] 6.8, 95% CI 3.2-14.4; P <.001) and presence of dissecting aneurysm (adjusted OR 3.5, 95% CI 1.3-9.3; P =.011) independently predicted rebleeding while history of hypertension (adjusted OR 0.4, 95% CI 0.2-0.8; P =.011) independently reduced its chances. 143 (32.3) patients died during hospitalization. Rebleeding emerged, among others, as an independent predictor of intrahospital mortality (adjusted OR 2.2, 95% CI 1.2-4.1; P =.009). CONCLUSION: UEV and presence of dissecting aneurysms are the strongest predictors of aneurysmal rebleeding. Their presence should be carefully evaluated in the acute management of poor-grade aSAH.

Intraoperative neurophysiological monitoring (IONM) represents one of the available technologies able to assess ischemia and aimed to improve surgical outcome reducing the treatment related morbidity in surgery for intracranial aneurysms. Many studies analyzing the impact of IONM are poised by the heterogeneity bias affecting the cohorts. We report our experience with IONM for surgery of unruptured middle cerebral artery (MCA) aneurysm in order to highlight its influence on functional and radiological outcome and surgical strategy. We retrospectively reviewed all MCA unruptured aneurysms treated between January 2013 and June 2021 by our institutional neurovascular team. Patients were divided into 2 groups according to the use of IONM. A total of 153 patients were included in the study, 52 operated on without IONM and 101 with IONM. The groups did not differ preoperatively regarding clinical status and aneurysm characteristics. Patients operated with IONM had better functional outcomes at discharge as well as at follow-up (p= 0.048, p=0.041) due to lower symptomatic ischemia and better radiological outcome due to lower rate of unexpected aneurysmal remnants (p= 0.0173). The introduction of IONM changed the use of temporary clipping (TeC), increasing its average duration (p= 0.01) improving the safety of dissecting and clipping the aneurysm. IONM in surgery for unruptured MCA aneurysm could improve the efficacy and safety of clipping strategy in the way it showed a role in changing the use of TeC and was associated to the reduction of unexpected aneurysmal remnants’ rate and improvement in both short- and long-term patient’s outcome.

Background: Subarachnoid hemorrhage (SAH) due to a middle cerebral artery (MCA) aneurysm rupture is often associated with an intracerebral hematoma (ICH) or intrasylvian hematoma (ISH). Methods: We reviewed 163 patients with ruptured MCA aneurysms associated with pure SAH or SAH plus ICH or ISH. The patients were first dichotomized according to the presence of a hematoma (ICH or ISH). Next, we performed a subgroup analysis comparing ICH versus ISH to explore their relationship with the most relevant demographic, clinical, and angioarchitectural features. Results: Overall, 85 patients (52%) had a pure SAH, and 78 (48%) had presented with an associated ICH or ISH. No significant differences were observed in the demographics or angioarchitectural features between the 2 groups. However, the Fisher grade and Hunt-Hess score were higher for the patients with hematomas. A good outcome was observed in a higher percentage of patients with pure SAH compared with those with an associated hematoma (76% vs. 44%), although the mortality rates were comparable. Age, Hunt-Hess score, and treatment-related complications were the main outcome predictors on multivariate analysis. Patients with ICH appeared worse clinically compared with those with ISH. We also found that older age, a higher Hunt-Hess score, larger aneurysms, decompressive craniectomy, and treatment-related complications were associated with poor outcomes among the patients with an ISH, but not an ICH, which appeared, per se, as a more severe clinical condition. Conclusions: Our study has confirmed that age, Hunt-Hess score, and treatment-related complications influence the outcome of patients with ruptured MCA aneurysms. However, in the subgroup analysis of patients with SAH associated with an ICH or ISH, only the Hunt-Hess score at onset appeared as an independent predictor of the outcome.

Objective: Ability to thrive after invasive and intensive treatment is an important parameter to assess in patients with glioblastoma multiforme (GBM). Karnofsky Performance Status (KPS) is used to identify those patients suitable for postoperative radiochemotherapy. The aim of the present study is to investigate whether machine learning (ML)-based models can reliably predict patients' KPS 6 months after surgery. Methods: A cohort of 416 patients undergoing surgery for a histopathologically confirmed GBM were collected from a multicentric database and split into a training and hold-out test set in an 80:20 ratio. Worsening of KPS at 6 months after surgery (compared with preoperative KPS) occurred in 138 patients (33.2%). Relevant preoperative, intraoperative, and immediately postoperative variables were selected by a recursive features selection algorithm (Boruta) and used to build 2 ML-based predictive models. Results: A random forest classifier and a random forest regressor were trained to predict 6 months postoperative KPS as a categorical (worsening vs. stable/improving) and continuous variables; they achieved, respectively, an area under the curve of 0.81 (95% confidence interval, 0.76–0.84) and a mean absolute error of 4.4 (95% confidence interval, 4.0–4.7). Leveraging the predictive value resulting from the combination of independent variables, the random forest classifier outperformed conventional statistics (area under the curve improvement of +21%). Conclusions: Two robust ML-based prediction models were successfully trained and internally validated. Considerable effort remains to improve the interpretation of the results when these predictions are used in a patient-centered care context.

Ao proceder a uma análise sistemática dos conceitos e principais características do serviço público e da recuperação judicial de empresas concessionárias de serviços públicos, o presente trabalho científico tem por fim analisar a importância dos princípios que regem a matéria. Os Princípios da Preservação e da Função Social da Empresa, aliados aos Princípios da Supremacia do Interesse Público, da Essencialidade, da Necessidade e da Continuidade do Serviço Público constituem arcabouço principiológico fundamental para interpretação e aplicação das normas legais e contratuais em casos de recuperação judicial de concessionárias de serviços públicos.

Ao proceder a uma análise sistemática dos conceitos e principais características do serviço público e da recuperação judicial de empresas concessionárias de serviços públicos, o presente trabalho científico tem por fim analisar a importância dos princípios que regem a matéria. Os Princípios da Preservação e da Função Social da Empresa, aliados aos Princípios da Supremacia do Interesse Público, da Essencialidade, da Necessidade e da Continuidade do Serviço Público constituem arcabouço principiológico fundamental para interpretação e aplicação das normas legais e contratuais em casos de recuperação judicial de concessionárias de serviços públicos.

Ao proceder a uma análise sistemática dos conceitos e principais características do serviço público e da recuperação judicial de empresas concessionárias de serviços públicos, o presente trabalho científico tem por fim analisar a importância dos princípios que regem a matéria. Os Princípios da Preservação e da Função Social da Empresa, aliados aos Princípios da Supremacia do Interesse Público, da Essencialidade, da Necessidade e da Continuidade do Serviço Público constituem arcabouço principiológico fundamental para interpretação e aplicação das normas legais e contratuais em casos de recuperação judicial de concessionárias de serviços públicos.

Ao proceder a uma análise sistemática dos conceitos e principais características do serviço público e da recuperação judicial de empresas concessionárias de serviços públicos, o presente trabalho científico tem por fim analisar a importância dos princípios que regem a matéria. Os Princípios da Preservação e da Função Social da Empresa, aliados aos Princípios da Supremacia do Interesse Público, da Essencialidade, da Necessidade e da Continuidade do Serviço Público constituem arcabouço principiológico fundamental para interpretação e aplicação das normas legais e contratuais em casos de recuperação judicial de concessionárias de serviços públicos.

This paper deals with the realisation of 3D printed cerebral aneurysms by using the direct light processing (DLP) technique. The aim was to improve the anatomy knowledge, training and surgical planning on individualised patient-specific basis. Computed tomography angiography and digital subtraction angiography of three patients were used to create 3D virtual models by using a commercial image-processing software. The DLP technique was aimed at realising the corresponding 3D physical models. These were firstly evaluated by the surgeons and then, if acceptable, used for the patient-specific treatment planning. All three models provided a comprehensive 3D representation of the related anatomical structure of the aneurysms improving the understanding of the surrounding vessels and their relationships. Moreover, the use of the DLP technology allowed fabricating the 3D models of the cerebral aneurysms in a low-time and low-cost consuming way.

Ao proceder a uma análise sistemática dos conceitos e principais características do serviço público e da recuperação judicial de empresas concessionárias de serviços públicos, o presente trabalho científico tem por fim analisar a importância dos princípios que regem a matéria. Os Princípios da Preservação e da Função Social da Empresa, aliados aos Princípios da Supremacia do Interesse Público, da Essencialidade, da Necessidade e da Continuidade do Serviço Público constituem arcabouço principiológico fundamental para interpretação e aplicação das normas legais e contratuais em casos de recuperação judicial de concessionárias de serviços públicos.

Background: Preoperative embolization is often considered mandatory in highly vascularized brain tumors to contain blood loss. However, not all lesions are amenable to endovascular preoperative embolization. In the literature, cases of preoperative and intraoperative embolization are described only by arterial catheterization, whereas experiences of tumor embolization through direct puncture of the lesion are anecdotal; furthermore these cases lack an intraoperative control method to assess the effects of the embolizing procedure itself. Methods: We describe the association of contrast enhanced ultrasonography (CEUS) and color Doppler ultrasonography (CDUS) to perform intraoperative embolization in an illustrative case of a posterior cranial fossa hemangioblastoma not amenable to a preoperative endovascular procedure. The combination of CEUS and CDUS was tested as an option for the intraoperative devascularization of tumors in which preoperative embolization is considered risky or not possible. Results: The association of CEUS and CDUS provided real-time intraoperative data that directly guided the intraoperative embolization and provided reliable data about the hemodynamic effects produced after the direct injection of an embolizing agent. The technique offered a true real-time definition of the anatomic characteristics of the lesion and its relationships with the adjacent structures while distinguishing feeding from draining vessels. Conclusions: This technique has been proved to be a valuable tool in the surgical resection of highly vascularized tumors and in the treatment of intracranial and spinal vascular lesions and can be considered an option in those cases in which preoperative embolization is not possible. It is a feasible, modern, and cost-effective intraoperative imaging technique that allows identification of unexposed anatomic structures, hence minimizing surgical exposition and surgical manipulation.

BACKGROUND: Increasing the extent of resection (EOR) is considered a main goal in high grade glioma (HGG) surgery. Significant advancements have been recently made to assist surgery: namely the use of 5-aminolevulinic acid (5ALA) and the application of contrast-enhanced ultrasound (CEUS) embody two of the most recently introduced tools in the neuro-oncology field. A combined approach including the two techniques has been suggested in literature. Our primary aim is to identify in which conditions CEUS final survey has a real impact in a 5-ALA guided context and assess which preoperative tumor characteristics, with specific attention to working corridors can predict strains of the fluorescence guided procedure and hence recommend the use of the combined technique. METHODS: Forty-nine HGG glioma surgeries were performed at our institution with the abovementioned protocol between January 2016 and June 2016. Based on preoperative MRI, we stratified glioma characteristics according to three determinants: localization (deep versus superficial), size (<3.5 versus >3.5 cm) and shape (regular versus irregular). RESULTS: CEUS modified 5-ALA guided resection in 11 cases (22.45%): this appeared to be associated with statistically significance to deep tumor localization (P=0.04) and irregular/multi-lobulated margins (P=0.003). On the other hand, tumor size alone did not appear as a statistically significant determinant. CONCLUSIONS: When dark corridors are presents or when overlying brain parenchyma hinders illumination, drawbacks to the 5-ALA assistance can be expected, hence CEUS final survey has a crucial role of 'refinement'. In those selected cases, an integrated 5ALA+CEUS protocol was shown as advisable in EOR improvement.

Residual and recurrent intracranial aneurysms after surgical clipping present a persistent risk of bleeding. Secondary coiling after incomplete clipping represents a strategy to occlude the residual sac: feasibility, bleeding risk and outcome were evaluated through a systematic review of literature along with the series of two tertiary referral neurovascular centres. Demographics, ruptured status, aneurysm morphology, topography, exclusion at surgery, timing of secondary coiling, complications, occlusion rate and outcome were analysed. Percentage of incidence and 95% CI were calculated for all variables. T test was used for continue variables, whereas Fisher’s test (two-sided) is for categorical ones. Overall, 102 patients (92 cases from literature and 10 cases from institutional series) were included. Mean age at diagnosis was 52.94 ± 12.17 years, and male/female ratio 0.5; 3/4 of aneurysms involved the anterior circulation, whereas 1⁄4 the posterior circulation. An aneurysmal neck remnant was described in 58.43% of cases, an aneurysmal sac remnant in 29.21% and a regrowth in 12.36%. Residual aneurysm rupture was reported in 22% of cases. Complete/near-complete occlusion after secondary coiling was observed in 70% of cases, a partial in 25.56% and a failure in 4.44%. Only one case of perforation was reported. Complications were comparable to standard endovascular procedures. Aneurysms remnants after clipping are often observed in cases difficult anatomical locations. Their bleeding risk is not negligible. Secondary coiling is a rescue strategy to effectively and safely secure the aneurysm remnant. Only in a minority of cases, it is a staged treatment after ‘remodelling’ of the aneurysm neck.

Thrombosed aneurysms of the middle cerebral artery (MCA) usually show large dimension and complex morphology with neck sclerosis and perforating vessels originating from the sac. Only limited experiences from case reports or small mixed series including thrombosed aneurysms in different locations are available in literature. To systematically review all the pertinent literature, a comprehensive literature review with the search terms “MCA, aneurysm, and thrombosis” and a pooled analysis including our institutional series were performed. We evaluated demographics, ruptured status, aneurysm morphology, topography and size, thrombosis extension, treatment, complications, final occlusion rate, and clinical outcome at follow-up. Data were individually extracted for each patient and included in a pool for the statistical analysis. Forty-two articles published between 1992 and 2016 were selected, including a total of 115 patients. Most of thrombosed aneurysms were saccular (67.6%), large or giant (86.7%), and located at the MCA bifurcation (67.3%). The treatment of choice was surgery in more than 80% of cases compared with the endovascular techniques, though the overall percentage of complications reported in the two groups was similar and around 20% of cases. Clinical outcome was favorable in more than 85% of patients after treatment. This is the first systematic review focusing on treatment and outcome of thrombosed MCA aneurysms. Our data depict their main angioarchictectural and clinical characteristics, proving the feasibility of their treatment with good prognosis in a high percentage of patients. However, complication and mortality rates of about 20 and 3.5%, respectively, are not negligible.

This study aims at demonstrating the feasibility of reproducing individualized patient-specific three-dimensional models of cerebral aneurysms by using the direct light processing (DLP) 3D printing technique in a low-time and inexpensive way. Such models were used to help neurosurgeons understand the anatomy of the aneurysms together with the surrounding vessels and their relationships, providing, therefore, a tangible supporting tool with which to train and plan surgical operations. The starting 3D models were obtained by processing the computed tomography angiographies and the digital subtraction angiographies of three patients. Then, a 3D DLP printer was used to print the models, and, if acceptable, on the basis of the neurosurgeon's opinion, they were used for the planning of the neurosurgery operation and patient information. All the models were printed within three hours, providing a comprehensive representation of the cerebral aneurysms and the surrounding structures and improving the understanding of their anatomy and simplifying the planning of the surgical operation.

Background: Fixation of bone flaps after craniotomy is a routine part of every neurosurgical procedure. The ideal fixation device should be safe, reliable, biologically inert, easy to use, and inexpensive and should not produce artifacts on neuroimaging. The authors describe a new device that meets these criteria. Methods: This is an observational, multicentric, and case series study of 56 patients who underwent a craniotomy and were subject to cranial bone flap fixation with the NT cranial small fixation system. A case–control group in whom titanium miniplates and screws were implanted was collected. All patients underwent CT scans of the head with 3D reconstruction at day 1 and day 90 postoperatively to evaluate bone flap position and fusion. Results: A total of 140 NT cranial small were implanted in 56 patients (mean age 44.2, range 22–63 years). The new device has shown stronger fixation qualities with optimal bone flap fusion and good cosmetic features. No surgical or relevant postsurgical follow-up complications have been associated with the device. Conclusion: Although this is a preliminary report in a relatively small number of patients, NT cranial small provides a safe, reliable, and easily applied postoperative cranial bone flap fixation system.

Background: One of the most valuable innovations in high-grade glioma surgery is 5-aminolevulinic acid (5-ALA). Fluorescence is a specific and sensitive indicator of metabolically active tumor tissue. In the published literature, the main focus has been placed on false-negative cases, with only a few articles addressing false positivity. The aim of the article was to highlight settings in which 5-ALA fluorescence does not necessarily mean tumor and to point out conditions in which intraoperative 5-ALA fluorescence has to be critically interpreted. Methods: Using PubMed, a review of pertinent literature was done to specifically investigate all conditions, including non-neoplastic and other metabolically active lesions, that can mimic high-grade gliomas and cause a misleading intraoperative diagnosis. In addition, an institutional case characterized by strong 5-ALA fluorescence in radionecrosis is presented. Results: Literature results were grouped in 2 main categories according to the field of application: oncologic setting (9 articles and 1 institutional case) and nononcologic settings (5 articles). Conclusions: As reported, 5-ALA-induced fluorescence is not limited to glioma but is also evident in nonglioma and non-neoplastic conditions. Critical interpretation of intraoperative fluorescence is therefore mandatory in recurrences and in atypical cases that might hinder alternative diagnoses.

It is common practice nowadays to derive spins and 3D shapes of asteroids from the inversion of photometric light curves. However, this method requires a good number of photometric points and dedicated observing sessions. On the other hand, the photometric observations carried out by the Gaia mission will be sparse and their number relatively small. For this reason, a multi-parametric shape described by a large number of elementary facets cannot probably be derived from Gaia data alone. Therefore, the Data Processing and Analysis Consortium (DPAC), implemented a simpler solution as an unattended data reduction pipeline which relies on three axial ellipsoids for the shape representation. However, overall accuracy of such triaxial shape solutions has to be assessed. How adequate is an ellipsoidal approximation to represent the overall properties of an irregular body? Which error is made on the volume in comparison a more accurate model with irregular shape? To answer these questions, we have implemented numerical procedures for comparing ellipsoids to more complex and irregular shapes, and we performed a full simulation of the photometric signal from these objects, using both shape representations. Implementing the same software algorithm that will be used for the analysis of Gaia asteroid photometry, rotation period, spin axis orientation and ellipsoidal shape were derived from simulated observations of selected Main Belt asteroids assuming a geometric scattering model (work is in progress for more complex scattering models). We found that the ellipsoids by photometry inversion are closely similar to the best-fitting ellipsoids of the simulated complex shapes and that the error on the asteroid volume (relative to a complex shape) is generally low, usually around $10\%$., Comment: 9 pages, 5 figures

It is common practice nowadays to derive spins and 3D shapes of asteroids from the inversion of photometric light curves. However, this method requires a good number of photometric points and dedicated observing sessions. On the other hand, the photometric observations carried out by the Gaia mission will be sparse and their number relatively small. For this reason, a multi-parametric shape described by a large number of elementary facets cannot probably be derived from Gaia data alone. Therefore, the Data Processing and Analysis Consortium (DPAC), implemented a simpler solution as an unattended data reduction pipeline which relies on three axial ellipsoids for the shape representation. However, overall accuracy of such triaxial shape solutions has to be assessed. How adequate is an ellipsoidal approximation to represent the overall properties of an irregular body? Which error is made on the volume in comparison a more accurate model with irregular shape? To answer these questions, we have implemented numerical procedures for comparing ellipsoids to more complex and irregular shapes, and we performed a full simulation of the photometric signal from these objects, using both shape representations. Implementing the same software algorithm that will be used for the analysis of Gaia asteroid photometry, rotation period, spin axis orientation and ellipsoidal shape were derived from simulated observations of selected Main Belt asteroids assuming a geometric scattering model (work is in progress for more complex scattering models). We found that the ellipsoids by photometry inversion are closely similar to the best-fitting ellipsoids of the simulated complex shapes and that the error on the asteroid volume (relative to a complex shape) is generally low, usually around $10\%$., Comment: 9 pages, 5 figures

Indocyanine green video angiography (ICG-VA) is a non-invasive, easy to use and very useful tool for various neurosurgical procedures. The first application was in neurovascular surgery, because it was born as an intravascular tracer for vessels visualization; this has been really useful in aneurysms, atero-venous malformations (AVMs) and dural fistulas surgery where identification, obliteration or patency of vessels is essential. introduced in vascular neurosurgery since 2003, icg-Va applications have broadened over time, both in vascular and in other neurosurgical fields. In 2003 Raabe et al. have been the first to describe the use of ICG-VA for intraoperative assessment of cerebral vascular flow, enabling visualization of vessel patency and aneurysm occlusion during aneurysm surgery. ICG-VA applications in vascular neurosurgery have significantly increased over time including complex aneurysms, bypass, atero-venous malformations (AVM) artero-venous fistulas (AVF), evaluation of cortical perfusion. The procedure can be easily repeated after 5-10 minutes. adverse reactions are comparable to those of other types of contrast media, with frequencies of 0.05% (hypotension, arrhythmia, or, more rarely, anaphylactic shock) to 0.2% (nausea, pruritus, syncope, or skin eruptions. The aim of the present study was to systematically analyze ICG-VA applications in vascular neurosurgery, highlighting the reported advantages and disadvantages, and discussing future perspectives.

The publisher regrets that the author Giuseppe Maria Della Pepa's name was printed incorrectly in the originally published article. The correct spelling of Dr Della Pepa's name is: Giuseppe Maria Della Pepa. The publisher would like to apologise for any inconvenience caused.

Objectives: 3D anatomical models are becoming a new frontier in surgery for planning and simulation on an individualized patient specific basis. Since 1999, 3D cerebral aneurysms models for neurosurgery have been proposed. The possibility of reproducing in a realistic 3D fashion the malformation with the surrounding vascular structures, provides important preoperative information for the treatment strategy. The same models can be used for training and teaching. Unfortunately stereolitography is often burdened by high costs and long times of production. These factors limit the possibility to use 3D models to plan surgeries in an easy daily fashion. Patients and methods: Our study enrolled 5 patients harboring cerebral aneurysms. DICOM data of each aneurysm were elaborated by an open source freeware to obtain CAD molds. Afterwards, the 3D models were produced using a fused deposition or a stereolitography printer. Results: Models were evaluated by Neurosurgeons in terms of quality and usefulness for surgical planning. Costs and times of production were recorded. Conclusions: Models were reliable, economically affordable and quick to produce.

Background In spite of the advent of neurointerventional treatment, different clinical and anatomical features are still strong indications for clipping of posterior communicating artery (PComA) aneurysms. But the experience of young neurosurgeons is increasingly limited, and therefore providing technical operative guidelines is a fundamental prerequisite to achieve the best aneurysm exclusion and avoid perioperative complications. Study Objective We describe a technical algorithm we use to teach young neurosurgeons how to approach carotid aneurysms that may help them develop a procedural memory and thus perform an efficient and safe surgery. Material and Methods We reviewed our last 10 years of institutional experience of > 150 cases of clipping ruptured and unruptured PComA aneurysms, analyzing our technical refinements and the difficulties in teaching residents and young neurosurgeons how to establish fundamental key points and design a didactic algorithm that includes operative instructions and safety rules. Results We recognized seven pragmatic technical key points regarding craniotomy, cisternostomy, proximal and distal control, aneurysm neck dissection, preservation of neurovascular structures, and clipping to use in a didactic algorithm for teaching residents and as operative instructions for inexperienced neurosurgeons. Conclusion In the setting of clipping PComA aneurysms, respect for surgical rules is of paramount importance to perform an efficacious and safe procedure and ensure the best aneurysm exclusion and preservation of neurovascular structures.

Background: In the surgical treatment of spinal dural arteriovenous fistulas (DAVFs), intraoperative definition of anatomic characteristics of the DAVF and identification of the fistulous point is mandatory to effectively exclude the DAVF. Case Description: Intraoperative ultrasound and contrast-enhanced ultrasound integrated with color Doppler ultrasound was applied in the surgical setting for a cervical DAVF to identify the fistulous point and evaluate correct occlusion of the fistula. Conclusions: Integration of intraoperative ultrasound and contrast-enhanced ultrasound is a simple, cost-effective technique that provides an opportunity for real-time dynamic visualization of DAVF vascular patterns, identification of the fistulous point, and assessment of correct exclusion. Compared with other intraoperative tools, such as indocyanine green videoangiography, it allows the surgeon to visualize hidden anatomic and vascular structures, minimizing surgical manipulation and guiding the surgeon during resection.

Background: Recently, the lateral supraorbital (LSO) keyhole variant of the standard pterional (PT) approach has been popularized for anterior skull base surgery, because it provides good anatomic exposition, reduced complications, and better aesthetic and functional results. However, these aspects have been formally compared only by a limited number of studies. We reviewed our experience with 50 consecutive anterior communicating artery (AComA) and A1/A2 aneurysms. Of these 50 patients, 25 had undergone the standard PT approach and 25, the LSO variant. We report the results in terms of exclusion of the aneurysm, postoperative complications, functional/masticatory outcomes, and aesthetic and patient satisfaction. Methods: From January 2014 to December 2015, 25 patients with unruptured AComA and A1/A2 aneurysms underwent the standard PT craniotomy. From January 2016 to March 2017, another 25 patients underwent the LSO technique. Results: No statistically significant differences were observed in the aneurysmal exclusion rate at angiographic follow-up or major complications. A statistically significant difference in the clinical outcome (Glasgow Outcome Scale) was evident only for the immediate postoperative time and was not significant during the follow-up period. The hospital stay was shorter in the LSO group. Minor complications, patient satisfaction, aesthetics, and functional and masticatory outcomes were significantly better statistically in the LSO group. Conclusions: The LSO approach demonstrated a lower rate of early clinical minor complications, with a reduction in hospitalization. The LSO approach provides better results for patient satisfaction, masticatory comfort, and cosmetic results. In our experience, the LSO approach is a safe and effective substitute to the standard PT craniotomy to treat unruptured AComA and A1/A2 aneurysms.

Background Ventriculoatrial (VA) shunt is a routine technique for the treatment of hydrocephalus. The correct position at the superior vena cava–right atrium junction is generally assessed by radiography. We present the first experience of an alternative, nonradiographic technique to assess the distal end of the VA shunts through an electrocardiographic (EKG) method. The technique has developed from the large experience of central venous catheters (CVC) worldwide; the EKG-guided method is a common and validated alternative to standard radiologic control of the location of the tip of any CVC. Methods Five consecutive patients underwent VA shunt with venous catheter positioned with the EKG-guided technique. The position of the catheter tip was verified by standard chest radiography. Results Four men and 1 woman (mean age, 45.4 years) underwent VA shunt for hydrocephalus with the EKG-guided technique. The side of internal jugular vein puncture was the right side in 4 cases and the left side in 1 case. As confirmed by radiography, all VA shunt tips were located within the correct range. There was no radiologic evidence of procedure-related complication or catheters that had to be replaced. Conclusions The EKG-guided technique for VA shunts is as accurate as fluoroscopy, but simpler, more readily available, less expensive, safer, and more cost effective. It reduces the need of radiography and radiologic exposition for both patients and operators. The EKG method may be a valid and cost-effective alternative to standard radiologic control in VA shunts, as for any central venous access device, and could become the preferential method for confirming tip position during VA shunt surgery.

Background: Spontaneous, non traumatic subarachnoid hemorrhage (SAH) is a significant clinical problem that occurs most commonly as a result of aneurysm rupture. In approximately 15 % of cases, nor aneurysm or other vascular malformation can be identified by cerebral angiography as origin of the hemorrhage, and these are commonly defined as idiopathic SAH (ISAH). Because of the negative angiography, limited extension of the bleeding with prevalent prepontine pattern and the benign prognosis, the venous causes has been preferred rather than the arterial ones. In the literature recent studies have suggested a possible contribution by primitive variants of Basal vein of Rosenthal (BVR) in its the pathogenesis of ISAH, commonly grouped according Watanabe classification (type A, B and C). In this paper we evaluated the prevalence of anatomical variants of BVR in ISAH. Methods: Venous drainage at angiography was retrospectively analyzed in 40 patients with ISAH and in 40 with unruptured aneurysms as controls. Results and conclusions: Previous studies displayed a significant prevalence of BVR type C variants in ISAH. Conversely in our study we recognized variant B as prevalent, in which the BVR bifurcates to drain anteriorly into the uncal vein and posteriorly into the Galenic system. Similarly to variant C (in which the BVR drains via perimesencephalic "bridging" veins into cavernous, sphenoparietal, petrosal sinus or directly into transverse sinus) also variant B might be subjected to those stress mechanisms and intrinsic system 'fragility' and for reasons yet to determine, sets off a consequent hemorrhage with clinical and radiological features typical of ISAH. © 2013 Springer-Verlag Wien.

Objective Dural closure is one of the most critical steps in neurosurgical procedures as it prevents many common postoperative complications. Methods of dural closure include the use of allogenic, autogenic, xenogenic, absorbable or synthetic materials together with sealant/glues or hemostatic compounds. Most common autogenic graft is galea-pericranium. This study aims to demonstrate how the intrinsic properties of the galea-pericranium make effectively useless the application of any glue in order to ensure the watertight integrity of the graft. Patients and methods 276 cases were included in the study. Postoperative dural-closure related complication in patients subjected to duraplasty were analysed in three groups undergoing different duraplasty techniques: galea-pericranium graft without sealants, galea-pericranium graft plus sealant, non-autologous dural patch plus sealant. Results No statistically significant differences between the three groups were observed in terms of subcutaneous fluid collection rate, CSF fistulas, brain abscesses, subdural empyemas, wound dehiscence, radiotherapic sequelae. Conclusions Our study shows that galea-pericranium alone (without sealants) is comparable to other duraplasty techniques that involve the use of sealants or of non-autologous pathches in terms of long term postoperative results. © 2014 Elsevier B.V.

Giant aneurysms of the basilar artery are rare and are frequently associated with obstructive hydrocephalus and brainstem compression. Treatment still remains a challenge both for neurosurgeons and for interventional neuroradiologists. Cases reported in the literature are anecdotal and, overall, their outcomes are poor. We present the case of a patient with a giant aneurysm of the basilar artery tip, involving the origin of both the posterior cerebral and superior cerebellar arteries, who underwent coiling and ventriculoperitoneal shunting for associated obstructive hydrocephalus. A pCONus ® stent (Phenox; Bochum, Germany) was detached with its petals opened over the ostia of the parent vessels, with the aim being to reconstruct the neck of the aneurysm and to preserve the flow in the parent vessel. Moreover, the presence of the stent was useful to maintain the coils within the dome of the aneurysm. The pCONus is a new neurovascular device that is also useful for treating cases of complex basilar artery aneurysms when the ostia of the parent vessel origin is at the level of the aneurysm neck.

Pterional craniotomy (PT) has long been the standard approach for the treatment of middle cerebral artery (MCA) aneurysms, even though it may cause temporalis muscle atrophy, facial nerve injury, and masticatory difficulties. Minipterional craniotomy (MPT) is an alternative approach that may provide the same surgical corridor, limiting the risk of postoperative esthetic and functional complications. From January 2011 to December 2014 we consecutively performed 68 craniotomies for surgical treatment of unruptured MCA aneuryms: 37 were standard PT and 31 were MPT. There were no significant differences in mean age, sex, and aneurysm topography between the two groups. The mean skin incision length was 14 cm in the PT group and 6 cm in the MPT group. According to the Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS), there were no significant differences in clinical outcome at discharge or follow-up between the two groups. Also, the rates of complete aneurysm exclusion were comparable. However, the number of patients complaining of masticatory disorders was higher among those treated with PT. Finally, the number of complications observed in the PT group was higher than that in the MPT group, but only the differences in mean hospitalization length and necessity for a dural patch for reconstruction were statistically significant. In conclusion, the MPT approach is a safe and effective alternative to the standard PT for the treatment of unruptured MCA aneurysms.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by a non-cell autonomous motor neuron loss. While it is generally believed that the disease onset takes place inside motor neurons, different cell types mediating neuroinflammatory processes are considered deeply involved in the progression of the disease. On these grounds, many treatments have been tested on ALS animals with the aim of inhibiting or reducing the pro-inflammatory action of microglia and astrocytes and counteract the progression of the disease. Unfortunately, these anti-inflammatory therapies have been only modestly successful. The non-univocal role played by microglia during stress and injuries might explain this failure. Indeed, it is now well recognized that, during ALS, microglia displays different phenotypes, from surveillant in early stages, to activated states, M1 and M2, characterized by the expression of respectively harmful and protective genes in later phases of the disease. Consistently, the inhibition of microglial function seems to be a valid strategy only if the different stages of microglia polarization are taken into account, interfering with the reactivity of microglia specifically targeting only the harmful pathways and/or potentiating the trophic ones. In this review article, we will analyze the features and timing of microglia activation in the light of M1/M2 phenotypes in the main mice models of ALS. Moreover, we will also revise the results obtained by different anti-inflammatory therapies aimed to unbalance the M1/M2 ratio, shifting it towards a protective outcome.

Sealing tissues by laser in neurosurgical procedures may overcome problems related to the use of conventional suturing methods which can be associated with various degrees of vascular wall damage. Despite the significant experimental and clinical achievements of the past, a standardized clinical application of laser-welding technology has not yet been implemented. The main problem is related to the use of common organic chromophores. A substantial breakthrough in the laser welding of biological tissues may come from the advent of nanotechnologies. In this paper we describe an experimental study, to confirm the feasibility of an innovative laser-assisted vascular repair (LAVR) technique based on diode laser irradiation and subsequent photoactivation of a hyaluronan solder embedded with near infrared (NIR) absorbing gold nanorods (GNRs), and to analyze the induced closuring effect in a follow-up study performed in animal model. Twenty New Zealand rabbits underwent closure of a 3-mm longitudinal incision performed on the common carotid artery (CCA) by means of 810 nm diode laser irradiation, in conjunction with the topical application of an optimized GNR composite. Effective closure of the arterial wound was accomplished by using very low laser intensity (30 W/cm2). The average CCA occlusion time was as low as 50 sec. Animals underwent different follow-up periods (2, 8, 30 days). After follow-up, they were re-anesthetized, the patency of the treated vessels was tested (Doppler analysis) and then the irradiated vessels were excised and subjected to histological evaluations. Morphological examinations of the samples documented the integrity of the vascular wall. No host reaction to nanoparticles occurred. Collagen and elastic fibers returned to their normal architecture 30 days after treatment. A Scanning Electron Microscopy (SEM) examination and immuno-histochemical analysis demonstrated a full re-endothelization of the vessel walls. We thus confirmed that a la

I Nuclei Galattici Attivi (AGN) sono tra le sorgenti più luminose dell’Universo e sono osservati in circa 10-20% delle galassie nell’Universo locale. Il meccanismo di generazione dell’energia di queste sorgenti è l’accrescimento di materia su un buco nero supermassivo (SMBH). Secondo il paradigma del Modello Unificato (UM) il SMBH è circondato da un assorbitore uniforme e anisotropo di gas e polveri, con geometria toroidale, che si estende da 1pc a 100pc. Anche se a livello generale l’UM è corretto, lavori recenti hanno evidenziato la necessità di formulare modelli alternativi per spiegare ad esempio la presenza di molteplici assorbitori disomogenei, a diverse distanze dal SMBH e in diversi stati fisici. Tra le argomentazioni in conflitto con l’UM vi è la variabilità spesso osservata negli spettri X degli AGN. Quando non deriva da una variazione intrinseca dell’emissione nucleare, essa implica che l’assorbitore è ‘’clumpy’’ e non è uniforme. Vari studi hanno anche mostrato che l’assorbitore non è sempre neutro: sono stati osservati outflow di grandi quantità di materiale parzialmente ionizzato (noti come “warm absorbers”) con velocità di outflow tra 100 e 1000 km/s, in circa il 50% degli AGN di tipo 1. Un’ulteriore complessità è rappresentata dalle osservazioni di assorbitori altamente ionizzati con alte velocità di outflow (vout>3000 km/s) noti come “ultrafast outflows”. La mia tesi si occupa della variabilità di assorbimento osservata negli spettri X degli AGN, fondamentale per testare le dimensioni, la struttura e la composizione della materia circumnucleare. In dettaglio, ho analizzato lo spettro X di due AGN, NGC 454E e Mrk 348, per cui sono disponibili dati dei satelliti Swift-BAT, Suzaku e XMM-Newton. NGC 454E è una galassia di Seyfert 2, parte di un sistema di galassie interagenti, a z=0.0122. Confrontando gli spettri di Suzaku e XMM, con distanza temporale di 6 mesi, ho notato un forte cambiamento della curvatura spettrale tra 3 keV e 6 keV, Active Galactic Nuclei (AGN) are among the most energetic sources in the Universe, and they are observed in about 10-20% of the galaxies in the local Universe. Their energy generation mechanism is accretion of matter on a central Supermassive Black Hole (SMBH). According to the most accredited paradigm, the Unified Model (UM), the SMBH is surrounded by an anisotropic uniform absorber of gas and dust, with a toroidal geometry, extending from 1 pc to 100 pc. Even if on a basic level the UM is correct, the need for alternative models was highlighted by the detection of several dishomogeneous absorbers, located at different distances from the SMBH, and at different physical states. Among the arguments in conflict with the UM there is the variability often observed in the X-ray spectra of AGN. When not resultant from an intrinsic variation of the nuclear emission, it implies that the underlying absorber is clumpy and not uniform. Many studies also showed that, besides being clumpy, the absorbing material is not always completely neutral. Significant amounts of outflowing partially-ionized material have been detected in about ∼50% of Type 1 AGN. These ionized absorbers are called “warm absorbers” and have outflow velocities in the range ∼100−1000 km/s. Furthermore, highly ionized absorbers with high outflow velocities (vout>3000 km/s, “ultrafast outflows”) have been observed. This thesis focuses on observations of absorption variability in the X-ray spectra of AGN, as a useful “tool” to test the size, structure and composition of the circumnuclear medium. In detail, I analysed the X-ray spectra of two AGN, NGC 454E and Mrk 348, for which X-ray data from Swift-BAT, Suzaku and XMM-Newton were available. NGC 454E is a red elliptical Seyfert galaxy in an interacting system, at z=0.0122. When comparing the Suzaku and XMM-Newton spectra, observed with 6 months delay, I noticed a dramatic change in the spectral curvature between 3 keV and 6 keV. The origin of the variability was

We report on a symptomatic case in which the whole intracranial blood supply was provided by a single vertebral artery as both internal carotid arteries were occluded and the contralateral vertebral artery was severely hypoplasic. The patient was treated by a flow-augmentation extracranial-intracranial bypass. Preoperative perfusion studies were essential in tailoring surgical strategy. Keypoints of the paper are contralateral perfusion changes after unilateral bypass surgery. The patient experienced a total recovery from symptoms and a bilateral improvement in brain perfusion, probably as consequence of post-operative hemodynamic rearrangement.

Objectives Dural arteriovenous fistulas (DAVFs) are a challenging condition in vascular neurosurgery. Disease natural history and its management is still debated. In the present paper we report our center series on DAVFs over a period of 10 years. Our data were compared with relevant literature. Patient and methods Our series includes 45 cases: 14 cavernous sinus, 11 transverse-sigmoid, 8 patients tentorial, 6 anterior cranial fossa, 5 patients spinal, 1 patient foramen magnum. Results and conclusions DVAFs distribution, clinical presentation and hemorrhagic risk are discussed. Cavernous sinus DAVFs are the most common site in our series. Other locations in order of frequency are transverse-sigmoid sinus, tentorial, anterior cranial fossa, spinal and foramen magnum. The majority of patients presented with non-aggressive symptoms. 18% presented with intracranial hemorrhage: all the hemorrhages occurred in high-grade DAVFs. For most patients, endovascular treatment, transarterial or transvenous, was the first option. Surgery was performed for the anterior cranial fossa DAVFs and other complex lesions draining mostly transverse-sigmoid sinus and tentorium. In 7% of cases a combination of endovascular + surgical treatment was used. Our series has been carefully analyzed in comparison 'side by side' with most relevant literature on DVAFs, focusing particularly on management strategies, therapeutic options and risks related to treatment.

This paper reviews literature about intraorbital ophthalmic artery aneurysms discussing presentation, aetiology and treatment options. In addition we report on a case of intraorbital ophthalmic artery aneurysm with acute onset of headache, visual loss and right eye ophthalmoplegia.

Objective Cerebral vasospasm (VS) is one of the factors that can most significantly worsen the prognosis after aneurysmal subarachnoid hemorrhage (SAH). A substantial body of evidence supports the idea that CSF diversion could prevent VS, even if this issue is still much debated. External ventricular drainage (EVD) is the recommended procedure for post-hemorrhagic hydrocephalus. In this study we analyzed whether EVD, placed for acute hydrocephalus, is effective in reducing the incidence of clinical and radiological cerebral vasospasm in patients who underwent endovascular treatment for aneurysmal SAH. Patients and methods We retrospectively studied the incidence of radiologically confirmed VS in 141 patients treated endovascularly for aneurysmal SAH: 80 underwent EVD for hydrocephalus, 61 did not undergo EVD. Results VS occurred in 8.75% of cases (7 patients) in the first groups, while in 22.95% (14 patients) in the second group. In addition, patients not treated with EVD display a prevalence of VS in lower Fisher grades compared to the other group. Conclusion Our data indicate that CSF drainage reduces the risk of vasospasms in patients with endovascular treatment for aneurysmal SAH. © 2014 Elsevier B.V.

Objective Duraplasty can be performed both by means of autologous tissues (such as galea-pericranium, temporal muscle, fascia lata) or by commercially available dural patches. Nowadays many neurosurgeons consider galea-pericranium duraplasty time-consuming, technically demanding or not adequate, thus dural surrogates are increasingly popular. In this prospective research we compared duraplasty using autologous galea-pericranium vs. dural patches in terms of postoperative long term results, ease/time required and costs. Patients and methods Research has been designed as prospective cohort study, that included 185 patients undergoing supratentorial elective neurosurgery with galea-pericranium or non-autologous duraplasty (minimum follow-up 12 months). Variables taken into account were: wound infection, CSF fistula, subcutaneous CSF collection, bone flap osteitis, brain abscess, empyema and tardive wound dehiscence (particularly after postoperative radiotherapy). Time for galea-pericranium collection, size of galea-pericranium harvest and dural defects were recorded in each case. Costs for non-autologous duroplasty were calculated. Results No statistically significant differences were evident in long term postoperative results between the two groups. Mean time of galea-pericranium collection is less than 2 min and enough galea-pericranium can be harvested in supratentorial approach to cover almost any dural defect. The only difference between the two groups is costs: an average of 268.7€/patient spent just for duraplasty. This figure is surely substantial if considered for the entire amount of surgeries performed in a department. Conclusions Considering that in our study long term results are equivalent, that galea-pericranium duraplasty is feasible and rapid, our indications are in favor of saving a considerable amount of money since an ideal autologous dural substitute is available and "free". © 2013 Elsevier B.V. All rights reserved.

Objective Indocyanine green video angiography (ICG-VA) is a non invasive, easy to use and a very useful tool for various neurosurgical procedures. Initially introduced in vascular neurosurgery since 2003, it's applications have broadened over time, both in vascular applications and in other neurosurgical fields. The objective of our study is to review all published literature about ICG-VA, cataloguing its different applications. Methods A systematic review of all pertinent literature articles published from January 2003 to May 2014 using Pubmed access was performed using pertinent keywords; cross check of references of selected articles was performed in order to complete bibliographical research. Results of research were grouped by pathology. Results and conclusions The paper systematically analyses ICG-VA different applications in neurosurgery, from vascular neurosurgery to tumor resection and endoscopic applications, focusing on reported advantages and disadvantages, and discussing future perspectives. © 2014 Elsevier B.V.

OBJECTIVE: Indocyanine green video angiography (ICG-VA) is a non invasive, easy to use and a very useful tool for various neurosurgical procedures. Initially introduced in vascular neurosurgery since 2003, it's applications have broadened over time, both in vascular applications and in other neurosurgical fields. The objective of our study is to review all published literature about ICG-VA, cataloguing its different applications. METHODS: A systematic review of all pertinent literature articles published from January 2003 to May 2014 using Pubmed access was performed using pertinent keywords; cross check of references of selected articles was performed in order to complete bibliographical research. Results of research were grouped by pathology. RESULTS AND CONCLUSIONS: The paper systematically analyses ICG-VA different applications in neurosurgery, from vascular neurosurgery to tumor resection and endoscopic applications, focusing on reported advantages and disadvantages, and discussing future perspectives.

In previous studies, the neurotrophic action of levocarnitine acetyl on the regeneration of the sciatic nerve in rats has been demonstrated. The present study investigated the particular effect of levocarnitine acetyl on the initial stages of sciatic nerve regeneration. In the first 8 days after sciatic nerve lesion caused by crushing (Group A) or cutting (Group B), the rats of both groups were divided into 2 subgroups: treated rats received daily intraperitoneal levocarnitine acetyl (a megadose of 100mg in saline solution); untreated rats only received saline solution. Treatment started on the day of operation. The regeneration growth rate of sensory fibres was studied using the pinch test. The size of the axotomized spinal motoneurons was studied using retrograde axonal tracers (horseradish peroxidase or Fast blue). The results showed that: (a) levocarnitine acetyl promoted the elongation of sensory fibres in the first 8 days following the crushing or sectioning of the sciatic nerve, but the data were only statistically significant (p < 0.01) for the first 3 days after crushing; (b) levocarnitine acetyl accelerated the velocity of sensory fibre regeneration when compared to untreated rats by 16% in the first 3 days after nerve crushing, by 14% in the first 4 days after nerve section, and by 32% from the 5th to the 8th day after nerve section; (c) levocarnitine acetyl promoted a significant reduction in spinal motoneuron hypertrophy when compared to untreated rats at both 4 and 8 days after sciatic nerve section. The composite results seem to indicate that levocarnitine acetyl antagonizes the metabolic shock of axotomized neurons and also promotes repair, synthesis and transport of organic material and reorganization of the cytoskeleton in the regenerated axon.

We present the results of the analysis of the X-ray spectrum of the Seyfert 2 Mrk 348, observed by Suzaku and XMM-Newton. The overall spectrum of Mrk 348 can be described by a primary power law continuum seen through three layers of absorption, of which one is neutral and two are ionised. Comparing Suzaku (2008) and XMM-Newton (2002) observations we find variability of the X-ray spectral curvature. We suggest that the variability can be explained through the change of column density of both the neutral and one of the ionised absorbers, together with a variation of the ionisation level of the same absorber. We thus confirm one of the main features presented in past works, where intrinsic column density variability up to $\sim 10^{23}$~cm$^{-2}$ was observed on time scales of months. We also find that the photon index of the underlying power law continuum ($\Gamma \sim 1.8$) is in agreement with the previous observations of this Seyfert 2., Comment: 13 pages, 6 figures

We study the link between the X-ray emission in radio-quiet AGNs and the accretion rate on the central Supermassive Black Hole using a statistically well-defined and representative sample of 71 type 1 AGNs extracted from the XMM-Newton Bright Serendipitous Survey. We search and quantify the statistical correlations between some fundamental parameters that characterize the X-ray emission, i.e. the X-ray spectral slope, and the X-ray "loudness", and the accretion rate, both absolute and normalized to the Eddington luminosity (Eddington ratio). We parametrize the X-ray loudness using three different quantities: the bolometric correction, the two-point spectral index and the disk/corona luminosity ratio. We find that the X-ray spectral index depends on the normalized accretion rate while the "X-ray loudness" depends on both the normalized and the absolute accretion rate. The dependence on the Eddington ratio, in particular, is probably induced by the X-ray spectral slope-Eddington ratio correlation. The two proxies usually adopted in the literature to quantify the X-ray loudness of an AGN, i.e. the bolometric correction and the two-point spectral index, behave differently, with the bolometric correction being more sensitive to the Eddington ratio and the two-point spectral index having a stronger dependence with the absolute accretion. The explanation of this result is likely related to the different sensitivity of the two parameters to the X-ray spectral index., Comment: 13 pages, 11 figures

We present the results of the analysis of the X-ray spectrum of the Seyfert 2 Mrk 348, observed by Suzaku and XMM-Newton. The overall spectrum of Mrk 348 can be described by a primary power law continuum seen through three layers of absorption, of which one is neutral and two are ionised. Comparing Suzaku (2008) and XMM-Newton (2002) observations we find variability of the X-ray spectral curvature. We suggest that the variability can be explained through the change of column density of both the neutral and one of the ionised absorbers, together with a variation of the ionisation level of the same absorber. We thus confirm one of the main features presented in past works, where intrinsic column density variability up to $\sim 10^{23}$~cm$^{-2}$ was observed on time scales of months. We also find that the photon index of the underlying power law continuum ($\Gamma \sim 1.8$) is in agreement with the previous observations of this Seyfert 2., Comment: 13 pages, 6 figures

We study the link between the X-ray emission in radio-quiet AGNs and the accretion rate on the central Supermassive Black Hole using a statistically well-defined and representative sample of 71 type 1 AGNs extracted from the XMM-Newton Bright Serendipitous Survey. We search and quantify the statistical correlations between some fundamental parameters that characterize the X-ray emission, i.e. the X-ray spectral slope, and the X-ray "loudness", and the accretion rate, both absolute and normalized to the Eddington luminosity (Eddington ratio). We parametrize the X-ray loudness using three different quantities: the bolometric correction, the two-point spectral index and the disk/corona luminosity ratio. We find that the X-ray spectral index depends on the normalized accretion rate while the "X-ray loudness" depends on both the normalized and the absolute accretion rate. The dependence on the Eddington ratio, in particular, is probably induced by the X-ray spectral slope-Eddington ratio correlation. The two proxies usually adopted in the literature to quantify the X-ray loudness of an AGN, i.e. the bolometric correction and the two-point spectral index, behave differently, with the bolometric correction being more sensitive to the Eddington ratio and the two-point spectral index having a stronger dependence with the absolute accretion. The explanation of this result is likely related to the different sensitivity of the two parameters to the X-ray spectral index., Comment: 13 pages, 11 figures

Dear Editor, Spontaneous, nontraumatic subarachnoid hemorrhage (SAH) is a significant clinical problem thatmost commonly occurs as a result of aneurysm rupture [4]. In approximately 15 % of cases, no aneurysm or other vascular malformation can be identified as the origin of the hemorrhage by cerebral angiography [4]. In the English literature, over time, several definitions have been used to define these cases: idiopathic SAH or perimesencephalic nonaneurysmal subarachnoid hemorrhage (PN-SAH), angiogram-negative subarachnoid hemorrhage (AN-SAH), and nonaneurysmal SAH [2, 4]. AN-SAH is nowadays the widely accepted term for such nosological entities [2]. In 1985, Van Gjin et al. named this type of subarachoid hemorrhage as perimesencephalic subarachnoid hemorrhage because of its anatomical blood distribution [8]. This definition was insufficient to describe those cases in which the hemorrhage extended to the carotid cisterns, Sylvian fissure, and/or interhemispheric fissure [7]. For this reason, the definition of AN-SAH has been popularized by the relevant literature. As a matter of fact, AN-SAH is definitely used as the prevalent and widely accepted definition in the medical literature [1]. But is it the best definition? We report two cases in which spontaneous SAH revealed an aneurysmal malformation that was clearly not responsible for the subarachnoid bleeding. Can these cases still be defined as AN-SAHs?

We study the link between the X-ray emission in radio-quiet AGNs and the accretion rate on the central Supermassive Black-Hole (SMBH) using a well-defined and statistically complete sample of 70 type1 AGNs extracted from the XMM-Newton Bright Serendipitous survey (XBS). To this end, we search and quantify the statistical correlations between the main parameters that characterize the X-ray emission (i.e. the X-ray spectral slope and the X-ray loudness), and the accretion rate, both absolute and relative to the Eddington limit (Eddington ratio). Here, we summarize and discuss the main statistical correlations found and their possible implications on current disk-corona models., Comment: 2 pages, in Proceedings of the Workshop "X-ray astronomy: towards the next 50 years!", Milano, October 1-5, 2012, Mem. S.A.It in press

We derive masses of the central super-massive black hole (SMBH) and accretion rates for 154 type1 AGN belonging to a well-defined X-ray-selected sample, the XMM-Newton Serendipitous Sample (XBS). To this end, we use the most recent "single-epoch" relations, based on Hbeta and MgII2798A emission lines, to derive the SMBH masses. We then use the bolometric luminosities, computed on the basis of an SED-fitting procedure, to calculate the accretion rates, both absolute and normalized to the Eddington luminosity (Eddington ratio). The selected AGNs cover a range of masses from 10^7 to 10^10 Msun with a peak around 8x10^8 Msun and a range of accretion rates from 0.01 to ~50 Msun/year (assuming an efficiency of 0.1), with a peak at ~1 Msun/year. The values of Eddington ratio range from 0.001 to ~0.5 and peak at 0.1., Comment: 14 pages, 11 figures. Accepted for publication in Astronomy & Astrophysics

We study the link between the X-ray emission in radio-quiet AGNs and the accretion rate on the central Supermassive Black-Hole (SMBH) using a well-defined and statistically complete sample of 70 type1 AGNs extracted from the XMM-Newton Bright Serendipitous survey (XBS). To this end, we search and quantify the statistical correlations between the main parameters that characterize the X-ray emission (i.e. the X-ray spectral slope and the X-ray loudness), and the accretion rate, both absolute and relative to the Eddington limit (Eddington ratio). Here, we summarize and discuss the main statistical correlations found and their possible implications on current disk-corona models., Comment: 2 pages, in Proceedings of the Workshop "X-ray astronomy: towards the next 50 years!", Milano, October 1-5, 2012, Mem. S.A.It in press

We derive masses of the central super-massive black hole (SMBH) and accretion rates for 154 type1 AGN belonging to a well-defined X-ray-selected sample, the XMM-Newton Serendipitous Sample (XBS). To this end, we use the most recent "single-epoch" relations, based on Hbeta and MgII2798A emission lines, to derive the SMBH masses. We then use the bolometric luminosities, computed on the basis of an SED-fitting procedure, to calculate the accretion rates, both absolute and normalized to the Eddington luminosity (Eddington ratio). The selected AGNs cover a range of masses from 10^7 to 10^10 Msun with a peak around 8x10^8 Msun and a range of accretion rates from 0.01 to ~50 Msun/year (assuming an efficiency of 0.1), with a peak at ~1 Msun/year. The values of Eddington ratio range from 0.001 to ~0.5 and peak at 0.1., Comment: 14 pages, 11 figures. Accepted for publication in Astronomy & Astrophysics