Is Guillain-Barrè syndrome triggered by SARS-CoV-2? Case report and literature review.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the infectious agent responsible for coronavirus disease 2019 (COVID-19). Respiratory and gastrointestinal manifestations of SARS-CoV-2 are well described, less defined is the clinical neurological spectrum of COVID-19. We reported a case of COVID-19 patient with acute monophasic Guillain-Barré syndrome (GBS), and a literature review on the SARS-CoV-2 and GBS etiological correlation. CASE DESCRIPTION: A 68 years-old man presented to the emergency department with symptoms of acute progressive symmetric ascending flaccid tetraparesis. Oropharyngeal swab for SARS-CoV-2 tested positive. Neurological examination showed bifacial nerve palsy and distal muscular weakness of lower limbs. The cerebrospinal fluid assessment showed an albuminocytologic dissociation. Electrophysiological studies showed delayed distal latencies and absent F waves in early course. A diagnosis of Acute Inflammatory Demyelinating Polyradiculoneuropathy (AIDP) subtype of GBS was then made. CONCLUSIONS: Neurological manifestations of COVID-19 are still under study. The case we described of GBS in COVID-19 patient adds to those already reported in the literature, in support of SARS-CoV-2 triggers GBS. COVID-19 associated neurological clinic should probably be seen not as a corollary of classic respiratory and gastrointestinal symptoms, but as SARS-CoV-2-related standalone clinical entities. To date, it is essential for all Specialists, clinicians and surgeons, to direct attention towards the study of this virus, to better clarify the spectrum of its neurological manifestations.

Emergency endovascular treatment of cavernous internal carotid artery acute bleeding with flow diverter stent: a single-center experience.

BACKGROUND AND OBJECTIVE: To describe our single-center experience in the treatment of cavernous internal carotid artery (ICA) acute bleeding with flow diverter stent (FDS), as a single endovascular procedure or combined with an endoscopic endonasal approach. METHODS: We analyze a case series of 5 patients with cavernous ICA acute bleeding, i.e., 3 iatrogenic, 1 post-traumatic, and 1 erosive neoplastic. After an immediate nasal packing to temporarily bleeding control, patients underwent digital subtraction angiography (DSA) to identify the site of the ICA injury. A concomitant balloon occlusion test (BOT) was performed, to exclude post-occlusive ischemic neurological damage. An FDS was placed with parallel intravenous infusion of abciximab in 3 cases and tirofiban in 2 cases. In two patients, an innovative "sandwich technique" combining the endovascular reconstruction with an extracranial intrasphenoidal cavernous ICA resurfacing with autologous flaps or grafts by endoscopic endonasal approach was performed. RESULTS: No patient had periprocedural ischemic-hemorrhagic complications. All patients had a regular clinical evolution, without general complications or new onset of focal neurological deficits. No further bleeding occurred in 3 patients, while 2 cases experienced a mild rebleeding in a period ranging from 5 to 15 days after the endovascular procedure. In these two cases, we proceeded with an endoscopic endonasal procedure to resurface the exposed ICA wall in the sphenoid sinus. CONCLUSIONS: Although the treatment of choice for cavernous ICA acute bleeding remains the occlusion of the injured vessel, in cases of poor hemodynamic compensation at the BTO, the endovascular FDS emergency placement can be effective. A combined endoscopic endonasal technique to support the extracranial side of the vessel using autologous flaps or grafts can be performed to prevent the risk of rebleeding.

The endoscopic diving technique in endonasal transsphenoidal surgery: how I do it.

BACKGROUND: The endoscopic diving technique (EDT) is a procedure utilized in endonasal endoscopy, which consists of irrigating the surgical cavity during tumor removal, with a continuous flow of pressurized saline solution. METHODS: The authors provide a detailed step-by-step description of the technique, shedding light on surgical tips and pitfalls. Advantages, disadvantages, and the most useful application of the technique are clarified and showed with a high-quality endoscopic video. CONCLUSION: EDT represents an effective and safe procedure. It allows a wide exploration of the surgical cavity, providing tumor hydro-dissection, assisting in bleeding control, and optimizing the efficacy of endoscopic transsphenoidal surgery.

Towards a functional atlas of human white matter.

OBJECTIVES: Although diffusion tensor imaging (DTI) and postmortem dissections improved the knowledge of white matter (WM) anatomy, functional information is lacking. Our aims are: to provide a subcortical atlas of human brain functions; to elucidate the functional roles of different bundles; to provide a probabilistic resection map of WM. EXPERIMENTAL DESIGN: We studied 130 patients who underwent awake surgery for gliomas (82 left; 48 right) with electrostimulation mapping at cortical and subcortical levels. Different aspects of language, sensori-motor, spatial cognition, and visual functions were monitored. 339 regions of interest (ROIs) including the functional response errors collected during stimulation were co-registered in the MNI space, as well as the resections' areas and residual tumors. Functional response errors and resection areas were matched with DTI and cortical atlases. Subcortical maps for each function and a probability map of resection were computed. PRINCIPAL OBSERVATIONS: The medial part of dorsal stream (arcuate fasciculus) subserves phonological processing; its lateral part [indirect anterior portion of the superior longitudinal fascicle (SLF)] subserves speech planning. The ventral stream subserves language semantics and matches with the inferior fronto-occipital fascicle. Reading deficits match with the inferior longitudinal fascicle. Anomias match with the indirect posterior portion of the SLF. Frontal WM underpins motor planning and execution. Right parietal WM subserves spatial cognition. Sensori-motor and visual fibers were the most preserved bundles. CONCLUSIONS: We report the first anatomo-functional atlas of WM connectivity in humans by correlating cognitive data, electrostimulation, and DTI. We provide a valuable tool for cognitive neurosciences and clinical applications.

Anatomo-functional study of the temporo-parieto-occipital region: dissection, tractographic and brain mapping evidence from a neurosurgical perspective.

The temporo-parieto-occipital (TPO) junction is a complex brain territory heavily involved in several high-level neurological functions, such as language, visuo-spatial recognition, writing, reading, symbol processing, calculation, self-processing, working memory, musical memory, and face and object recognition. Recent studies indicate that this area is covered by a thick network of white matter (WM) connections, which provide efficient and multimodal integration of information between both local and distant cortical nodes. It is important for neurosurgeons to have good knowledge of the three-dimensional subcortical organisation of this highly connected region to minimise post-operative permanent deficits. The aim of this dissection study was to highlight the subcortical functional anatomy from a topographical surgical perspective. Eight human hemispheres (four left, four right) obtained from four human cadavers were dissected according to Klingler's technique. Proceeding latero-medially, the authors describe the anatomical courses of and the relationships between the main pathways crossing the TPO. The results obtained from dissection were first integrated with diffusion tensor imaging reconstructions and subsequently with functional data obtained from three surgical cases, all resection of infiltrating glial tumours using direct electrical mapping in awake patients. The subcortical limits for performing safe lesionectomies within the TPO region are as follows: within the parietal region, the anterior horizontal part of the superior longitudinal fasciculus and, more deeply, the arcuate fasciculus; dorsally, the vertical projective thalamo-cortical fibres. For lesions located within the temporal and occipital lobes, the resection should be tailored according to the orientation of the horizontal associative pathways (the inferior fronto-occipital fascicle, inferior longitudinal fascicle and optic radiation). The relationships between the WM tracts and the ventricle system were also examined. These results indicate that a detailed anatomo-functional awareness of the WM architecture within the TPO area is mandatory when approaching intrinsic brain lesions to optimise surgical results and to minimise post-operative morbidity.

Clinical Relevance and Interplay between miRNAs in Influencing Glioblastoma Multiforme Prognosis.

Glioblastoma multiforme (GBM) is usually treated with surgery followed by adjuvant partial radiotherapy combined with temozolomide (TMZ) chemotherapy. Recent studies demonstrated a better survival and good response to TMZ in methylguanine-DNA methyltransferase (MGMT)-methylated GBM cases. However, approximately 20% of patients with MGMT-unmethylated GBM display an unexpectedly favorable outcome. Therefore, additional mechanisms related to the TMZ response need to be investigated. As such, we decided to investigate the clinical relevance of six miRNAs involved in brain tumorigenesis (miR-181c, miR-181d, miR-21, miR-195, miR-196b, miR-648) as additional markers of response and survival in patients receiving TMZ for GBM. We evaluated miRNA expression and the interplay between miRNAs in 112 IDH wt GBMs by applying commercial assays. Then, we correlated the miRNA expression with patients' clinical outcomes. Upon bivariate analyses, we found a significant association between the expression levels of the miRNAs analyzed, but, more interestingly, the OS curves show that the combination of low miR-648 and miR-181c or miR-181d expressions is associated with a worse prognosis than cases with other low-expression miRNA pairs. To conclude, we found how specific miRNA pairs can influence survival in GBM cases treated with TMZ.

Identification of MGMT Downregulation Induced by miRNA in Glioblastoma and Possible Effect on Temozolomide Sensitivity.

Glioblastoma multiforme (GBM) remains one of the tumors with the worst prognosis. In recent years, a better overall survival (OS) has been described in cases subjected to Gross Total Resection (GTR) that were presenting hypermethylation of Methylguanine-DNA methyltransferase (MGMT) promoter. Recently, also the expression of specific miRNAs involved in MGMT silencing has been related to survival. In this study, we evaluate MGMT expression by immunohistochemistry (IHC), MGMT promoter methylation and miRNA expression in 112 GBMs and correlate the data to patients' clinical outcomes. Statistical analyses demonstrate a significant association between positive MGMT IHC and the expression of miR-181c, miR-195, miR-648 and miR-767.3p between unmethylated cases and the low expression of miR-181d and miR-648 and between methylated cases and the low expression of miR-196b. Addressing the concerns of clinical associations, a better OS has been described in presence of negative MGMT IHC, in methylated patients and in the cases with miR-21, miR-196b overexpression or miR-767.3 downregulation. In addition, a better progression-free survival (PFS) is associated with MGMT methylation and GTR but not with MGMT IHC and miRNA expression. In conclusion, our data reinforce the clinical relevance of miRNA expression as an additional marker to predict efficacy of chemoradiation in GBM.

The Role of the Transorbital Superior Eyelid Approach in the Management of Selected Spheno-orbital Meningiomas: In-Depth Analysis of Indications, Technique, and Outcomes from the Study of a Cohort of 35 Patients.

Objective Primary goal in spheno-orbital meningioma (SOM) surgery still remains complete resection. Nevertheless, given their highly infiltrative nature, a growing body of literature suggests to shift toward function-sparing surgeries. We here present our experience in the management of SOMs through the endoscopic superior eyelid approach (SEA). Methods Surgical database from our multidisciplinary work group was retrospectively reviewed to identify patients treated for SOMs in the last 10 years by our senior authors, analyzing and correlating clinical, radiological, and outcome variables among the different approaches used. Results There were 35 patients (mean age of 57.3 ± 12.86 years), with a mean follow-up of 31.5 months (range: 6-84 months). The most common preoperative complaint was proptosis (62.9%) followed by diplopia and visual deficit. Greater and lesser sphenoid wings were the areas mainly involved by the pathology (91.4% and 88.6%, respectively), whereas orbital invasion was evidenced in one-third of cases. Patients were operated on through craniotomic (48.6%), endoscopic superior eyelid (37.1%), and combined cranioendoscopic (14.3%) approaches. Simpson grades 0 to II were accomplished in 46.2% of SEA and 76.5% of craniotomies. All patients with a preoperative visual deficit improved in the postoperative period, independently from the approach used. On patients who underwent endoscopic SEA, there was improved their short-/long-term postoperative Karnofsky Performance Status. Conclusions Endoscopic SEA is a safe and effective alternative to transcranial approaches in very selected cases of SOMs, where the planned primary objective was to obtain a maximally safe resection, aimed at symptom relief, rather than a gross total resection at any cost.

Endoscopic-assisted orbital exenteration: Technical feasibility and surgical results from a single-center consecutive series.

The purposes of this study were to describe the endoscopic-assisted orbital exenteration surgical techniques, to report preliminary outcomes and to discuss advantages, indications and limitations of this approach. All patients who underwent endoscopic-assisted orbital exenteration at a single tertiary-care center were retrospectively reviewed. A concomitant reconstruction was performed in all cases. The extent of surgical resection was tailored to the size and location of tumor and was classified into four subtypes. A total of 40 patients were included in this series. Orbital exenteration type 1 was performed in 7 cases, type 2 in 11 cases, type 3 in 19 cases, and type 4 in 3 cases. The reconstruction was performed with a pedicled temporal flap in 5 patients and with a free vascularized flap in 34 cases. A radical resection of disease was obtained in 32 cases. After a mean follow-up of 36 months, 14 patients died of disease, one patient died of other causes, 7 are alive with disease, and 18 patients are currently alive without evidence of disease. The preliminary data emerging from this case-series support the feasibility and safety of endoscopic-assisted orbital exenteration.

Endoscopic Endonasal Pituitary Hemi-Rotation Approach to the Upper Clivus: Anatomical Study and Clinical Report.

AIM: To report on the endoscopic endonasal pituitary hemi-rotation approach (EPHRA) in a preclinical setting and in a preliminary clinical experience. MATERIAL AND METHODS: EPHRA was performed in five fresh-frozen head and neck specimens (a total of 10 sides) and in a selected case of a right-sided dorsum sellae chordoma. RESULTS: The approach described allowed exposure of the lateral part of the upper clivus in all the specimens and in the case reported. To evaluate the maximum possible degree of hypophyseal hemi-rotation, the hemi-rotation angle (HRA) of the approach was measured and reported for all sides of the specimens. In 9 out of 10 cadaver head sides, and in the clinical case, it was possible to avoid sectioning of the inferior hypophyseal artery. No complications occurred during or after the procedure. CONCLUSION: EPHRA represents an addition to the techniques already described and finds indications in case of non-massive neoformations of the lateral upper clivus. Clinical applications and limitations still need to be clarified in further clinical studies.

Endoscopic Endonasal Transethmoidal-Transsphenoidal Approach to a Cavernous Sinus Chondrosarcoma.

Objective We illustrate a cavernous sinus chondrosarcoma treated with an endoscopic endonasal transethmoidal-transsphenoidal approach. Design Case report of a 15-year-old girl with diplopia and esotropia due to complete abducens palsy. Preoperative images showed a right cavernous sinus lesion with multiple enhanced septa and intralesional calcified spots ( Fig. 1 ). Considering tumor location and the lateral dislocation of the carotid artery, an endoscopic endonasal approach was performed to relieve symptoms and to optimize the target geometry for adjuvant conformal radiotherapy. Setting The study was conducted at University of Insubria, Department of Neurosurgery, Varese, Italy. Participants Skull base team was participated in the study. Main Outcome Measures A transethmoidal-transsphenoidal approach was performed by using a four-hand technique. We used a route lateral to medial turbinate to access ethmoid and the sphenoid sinus. During the sphenoid phase, we exposed the medial wall of the cavernous sinus ( Fig. 2 ) and the lesion was then removed using curette. Skull base reconstruction was performed with fibrin glue and nasoseptal flap. Results No complications occurred after surgery, and the patient experienced a complete recovery of symptoms. A postoperative magnetic resonance imaging showed a small residual tumor inside the cavernous sinus ( Fig. 1 ). After percutaneous proton-bean therapy, patient experienced only temporary low-grade toxicity with local control within 2 years after treatment completion. Conclusion Endoscopic endonasal extended approach is a safe and well-tolerated procedure that is indicated in selected cases (intracavernous tumors, soft tumors not infiltrating the vessels and/or the nerves). A tailored approach according to tumor extension is crucial for the best access to the compartments involved. The link to the video can be found at: https://youtu.be/TsqXjqpuOws .

Caring for acute coronary syndrome and other time-sensitive medical emergencies during the coronavirus disease 2019 pandemic in Northern Italy: report from a hub center.

BACKGROUND: The Lombardy region, in Northern Italy, suffered a major outbreak of Coronavirus disease 2019 (COVID-19) at the end of February 2020. The health system was rapidly overwhelmed by the pandemic. It became evident that patients suffering from time-sensitive medical emergencies like stroke, cerebral hemorrhage, trauma and acute myocardial infarction required timely, effective and safe pathways to be treated. The problem was addressed by a regional decree that created a hub-and-spoke system for time-sensitive medical emergencies. METHODS: We report the re-organizational changes adopted at a hub hospital (despite having already destined to COVID-19 patients most resources), and the number of emergent procedures for medical emergencies on the first 30-day of activity. These data were compared with the hospital activity in the same period of the previous year. RESULTS: Organizational changes were implemented in few hours. Dedicated pathways for non-COVID-19 patients affected by a medical emergency were set up in the emergency department, in the labs and in the operating theater. Ten intensive beds were implemented from a high-dependency unit; two operating rooms were reserved 24 h/day to neurosurgical or trauma emergencies. The number of emergent procedures was not different from that of the previous year, no admission refusal, no treatment delay and no viral transmission to the treated patients were recorded. No viral transmission to health care workers was observed. CONCLUSIONS: Re-organization of a hospital in order to adopt a hub-and-spoke model resulted feasible and allowed to face acute coronary syndrome and other time-sensitive medical emergencies timely and safely.

Acute Hydrocephalus Caused by Cerebellar Abscess in HIV-Negative Castleman's Disease.

Castleman's disease (CD) is a rare and indolent hematologic disorder characterized by solitary bulky adenopathy. Multiple nodal nonbulky localizations are described, while central nervous system involvement is rare. Immunodeficiency is associated with higher incidence of CD, and HIV serology should be performed at initial diagnosis. We report the case of a 64-year-old HIV-negative man affected by CD, presenting with acute hydrocephalus caused by a large cerebellar abscess.

The Impact of Surgery in IDH 1 Wild Type Glioblastoma in Relation With the MGMT Deregulation.

Object: The treatment of choice in glioblastoma (GBM) is the maximal surgical extent of resection (EOR) followed by adjuvant chemo-radiotherapy. Furthermore, methylguanine-DNA methyltransferase (MGMT) promoter methylation is associated with prolonged overall survival (OS) and progression free survival (PFS). The objective of the present study is correlate the biomolecular aspects in relation with EOR. Materials and methods: We analyzed a series of 116 patients with IDH-1 wild type GBM and different EOR (Gross Total Resection-GTR-, Partial Resection-PR- and Biopsy), treated with adjuvant chemo-radiotherapy. The MGMT status was analyzed in terms of promoter methylation and protein expression. Results: When GTR was possible, OS and PFS were significantly better compared to the other two groups (p = 0.001 and p = 0.035, respectively). MGMT methylation was significantly associated with better OS in the biopsy group (p = 0.022) and better OS and PFS in PR (p = 0.02 and p = 0.012, respectively), but not in the GTR group (p = 0.252 for OS, p = 0.256 for PFS) nor the PFS in the biopsy group (p = 0.259). MGMT protein expression levels do not show any association with OS and PFS, regardless of the type of surgery. Conclusions: Our study confirms the positive association of a safe maximal EOR with better OS and PFS, and indicates a positive prognostic value of MGMT methylation status only in case of the presence of residual tumor tissue. MGMT protein expression seems not to play a clinical role in relation with the type of surgery.

Infrequent Hemorrhagic Complications Following Surgical Drainage of Chronic Subdural Hematomas.

Chronic subdural hematomas mainly occur amongst elderly people and usually develop after minor head injuries. In younger patients, subdural collections may be related to hypertension, coagulopathies, vascular abnormalities, and substance abuse. Different techniques can be used for the surgical treatment of symptomatic chronic subdural hematomas : single or double burr-hole evacuation, with or without subdural drainage, twist-drill craniostomies and classical craniotomies. Failure of the brain to re-expand, pneumocephalus, incomplete evacuation, and recurrence of the fluid collection are common complications following these procedures. Acute subdural hematomas may also occur. Rarely reported hemorrhagic complications include subarachnoid, intracerebral, intraventricular, and remote cerebellar hemorrhages. The causes of such uncommon complications are difficult to explain and remain poorly understood. Overdrainage and intracranial hypotension, rapid brain decompression and shift of the intracranial contents, cerebrospinal fluid loss, vascular dysregulation and impairment of venous outflow are the main mechanisms discussed in the literature. In this article we report three cases of different post-operative intracranial bleeding and review the related literature.

Lhermitte-Duclos disease. A case report.

Lhermitte-Duclos disease is a rare pathologic condition consisting of a dysplastic gangliocytoma of the cerebellum. Its association with phacomatosis and an autosomal dominant neoplastic syndrome, Cowden's syndrome is also known. Modern neuroimaging contributes to a correct diagnosis and pre- and postoperative evaluation. Here we describe the morphologic and metabolic aspects of the disease as shown by conventional MRI, diffusion imaging and spectroscopy in a 31-year-old woman. In addition, the specific neuroradiologic characteristics are presented and discussed in the light of the main pathologic and clinical features, such as hypertrophy of the cerebellar folia associated with white matter atrophy.

Early-stage microvascular alterations of a new model of controlled cortical traumatic brain injury: 3D morphological analysis using scanning electron microscopy and corrosion casting.

OBJECT: This study was performed to study the microvascular changes that occur during the first 12 hours after traumatic brain injury (TBI) using the corrosion casting technique. METHODS: The authors performed a qualitative and quantitative morphological study of the changes in cerebral vessels at acute (3 hours) and subacute (12 hours) stages after experimental TBI. They used a model of controlled cortical impact (CCI) injury induced by a recently developed electromagnetic device (impactor), focusing their observations mainly on the microvascular alterations responsible for the formation and maintenance of tissue edema and consequent brain swelling during the first hours after TBI. They used corrosion casting, scanning electron microscopy (SEM), light microscopy, and transmission electron microscopy (TEM) to obtain a morphological qualitative map with both 2D and 3D details. RESULTS: Scanning electron microscopy analysis of vascular casts documented in 3 dimensions the typical injuries occurring after a TBI: subdural, subarachnoid, and intraparenchymal hemorrhages, along with alterations of the morphological characteristics and architecture of both medium-sized and capillary vessels, including ectasia of pial vessels, sphincter constrictions at the origin of the perforating vessels, focal swelling of perforating vessels, widening of intercellular junctions, and some indirect evidence of structural impairment of endothelial cells. All of these vascular alterations were confirmed in 2D analyses using light microscopy and TEM. CONCLUSIONS: The corrosion casting-SEM technique applied to a CCI experimental model proved to be a reliable method for studying the pathophysiology of the vascular alterations occurring at acute and subacute stages after CCI injury. It was also possible to obtain topographical localization of the vascular and cellular events that usually lead to hyperemia, edema, and brain swelling. Moreover, by applying informatic software to anatomical images it was possible to perform quantification and statistical analysis of the observed events.

Isolation and expansion of human and mouse brain microvascular endothelial cells.

Brain microvascular endothelial cells (BMVECs) have an important role in the constitution of the blood-brain barrier (BBB). The BBB is involved in the disease processes of a number of neurological disorders in which its permeability increases. Isolation of BMVECs could elucidate the mechanism involved in these processes. This protocol describes how to isolate and expand human and mouse BMVECs. The procedure covers brain-tissue dissociation, digestion and cell selection. Cells are selected on the basis of time-responsive differential adhesiveness to a collagen type I-precoated surface. The protocol also describes immunophenotypic characterization, cord formation and functional assays to confirm that these cells in endothelial proliferation medium (EndoPM) have an endothelial origin. The entire technique requires ∼7 h of active time. Endothelial cell clusters are readily visible after 48 h, and expansion of BMVECs occurs over the course of ∼60 d.

Human and mouse brain-derived endothelial cells require high levels of growth factors medium for their isolation, in vitro maintenance and survival.

BACKGROUND: Brain microvascular endothelial cells (BMVECs) constitute the primary limitation for passage of ions and molecules from the blood into the brain through the blood brain barrier. Numerous multi-step procedures for isolating and culturing BMVECs have been described. However, each one demonstrates major limitations in purity of culture and/or low proliferation rate. Our goal was to study the efficiency of our pending patent medium, Endothelial Proliferation Medium (EndoPM), on the isolation and purification of human and murine BMVECs. METHODS: BMVECs, cultured in EndoPM were compared to those cultured in a commercial medium EBM. Cultures were characterized by flow cytometric analysis, lineage differentiation, the ability to form tube-like structure, immunofluorescence, molecular analyses and also in an in vivo model assay. Moreover permeability was assayed by monitoring the passage of Dextran-FITC through a tight monolayer of BMVECs grown to confluence in Boyden chambers. One way Anova two-tailed test was utilized for all statistical analyses. RESULTS: The properties of ECs in human and murine BMVECs is confirmed by the expression of endothelial markers (CD31, CD105, CD146, Tie-2 and vWF), of representative proangiogenic genes (ICAM1, VCAM1 and integrin ITGAV), of considerable tube-forming ability, with low-density lipoprotein uptake, eNOS and GLUT-1 expression. Furthermore cells are able to express markers of the junctional architecture as VE-cadherin, ß-catenin and Claudin-5 and greatly reduce dextran permeability as barrier functional test. Moreover BMVECs spontaneously organize in vascular-like structures and maintain the expression of endothelial markers in an in vivo xenograft model assay. The significant effect of EndoPM is confirmed by the study of proliferation index, survival index and the behaviour of BMVECs and fibroblasts in co-culture conditions. CONCLUSION: Herein we describe a simple and reproducible method for the isolation and expansion of human and mouse BMVECs, based on a newly formulated medium (EndoPM) with optimized concentration of growth factors (EGF, FGF-2 and Bovine Brain Extract-BBE). This procedure should facilitate the isolation and expansion of human and mouse BMVECs with extended lifetime, good viability and purity. This approach may provide an effective strategy to aid phenotypical and functional studies of brain vessels under physiological and pathological conditions.