Occipital emissary vein existence and its impact on the diagnosis of idiopathic intracranial hypertension in pediatric patients.

PURPOSE: This study aimed to investigate the efficacy of occipital emissary vein (OEV) detection in the diagnosis of idiopathic intracranial hypertension (IHH) in the pediatric age group, and to compare the prevalence and luminal diameter of OEV in patients with IHH and in healthy control subjects. METHODS: Conventional magnetic resonance imaging findings were assessed in the patients with IHH and in healthy control subjects who were under the age of 18, by two observers. The presence and luminal dimension of OEV and transverse sinus stenosis were also evaluated and compared between these two groups with magnetic resonance venography techniques. RESULTS: The rate of OEV existence was 7 times higher in the IIH group compared to the control group based on the second observer outcome (p = 0.010, OR = 7.0), with a very good interobserver agreement (Ƙ = 0.85). The dimension of OEV ranged between 0.6 and 2.5 mm. There was no correlation found between the opening pressure and the dimension of OEV (p = 0.834). CONCLUSION: In conclusion, OEV existence could be an additional radiological finding for diagnosing IHH among pediatric patients, alongside other conventional findings.

The Basal or Sphenopetrosal Superficial Middle Cerebral Vein Type.

Background and Objectives: The adult superficial middle cerebral vein (SMCV) commonly drains into the middle cranial fossa. However, different embryonic types persist, in which the SMCV drains into the lateral sinus. The basal type of SMCV coursing on the middle fossa floor is a scarce variant. Materials and Methods: During a retrospective study of archived computed tomography angiography (CTA) and magnetic resonance angiography (MRA) files, three rare adult cases of the basal or sphenopetrosal type of SMCV were found and further documented. Results: In the first case, which was evaluated via CTA, the basal type of SMCV formed a sagittal loop. It continued on the middle fossa floor, over a dehiscent tegmen tympani, to drain into the lateral sinus. In the second case, documented via MRA, the basal type of SMCV's anterior loop was in the coronal plane and closely related to the internal carotid artery and the cavernous sinus. It continued with the basal segment over a dehiscent glenoid fossa of the temporomandibular joint (TMJ). In the third case, documented via CTA, the initial cerebral part of the SMCV had a large fenestration. The middle fossa floor coursed within a well-configured sulcus of the SMCV and received a tributary through the tympanic roof. Its terminal had a tentorial course. Conclusions: Beyond the fact that such rare variants of the SMCV can unexpectedly interfere with specific approaches via the middle fossa, dehiscences of the middle fossa floor beneath such variants can determine otic or TMJ symptoms. Possible loops and fenestrations of the SMCV should be considered and documented preoperatively.

Spontaneous thrombosis of vein of Galen malformation managed with surgical resection: a case­based review.

INTRODUCTION: Vein of Galen malformation (VOGM) is an exceptionally uncommon form of congenital intracranial vascular malformations. It is highly unusual for this lesion to spontaneously thrombose. The clinical presentation of a patient may range from being asymptomatic to critically ill. The underlying pathophysiological mechanisms that cause spontaneous thrombosis are still poorly understood. METHODS AND RESULTS: The literature on spontaneous thrombosis of VOGM was systematically reviewed, analyzed, and summarized with a focus on its pathophysiology, types, clinical presentations, diagnosis, management, and outcomes. It was also illustrated with a case presentation. The case presents an unusual presentation and location of a VOGM in a 2-year-old boy who was successfully treated with surgical resection. CONCLUSIONS: A handful of cases of thrombosed VOGM have been reported worldwide where surgery was used to treat the condition. Low-flow fistulas of the mural type are prone to spontaneous thrombosis, have delayed clinical presentations, and are typically diagnosed in young children. Among the many possible manifestations, hydrocephalus is by far the most common. In the absence of blood flow, MRI is the diagnostic test of choice. Depending on the patient's symptoms, surgery to either remove the aneurysm or divert the cerebrospinal fluid usually results in a good prognosis.

Adaptative Diploic Vein Bypass of the Superior Sagittal Sinus in a Large Falcine Meningioma.

We describe an adaptative bypass at the posterior third of the superior sagittal sinus (SSS) through the parietal diploe veins related to a large falcine meningioma on a 55-year-old lady with progressive headaches and mild left hemiparesis. Cranial imaging revealed a large tumor at the posterior third of the cerebral falx, compatible with meningioma. Imaging also revealed lack of continuity of the superior sagittal sinus at that region. Large diploic veins were seen bypassing the segment of the SSS affected by the tumor. An "L"-shaped modified posterior interhemispheric craniotomy was performed to avoid traversing the diploic veins. Near-total resection of the meningioma was accomplished. Postoperative imaging revealed a small remnant invading the SSS, which was treated with adjuvant radiotherapy. The patient tolerated the procedure well and was discharged to rehabilitation unit on postoperative day 5 with no neurologic deficits.

Symptomatic Developmental Venous Anomaly: State-of-the-Art Review on Genetics, Pathophysiology, and Imaging Approach to Diagnosis.

Developmental venous anomalies (DVAs) are the most common slow-flow venous malformation in the brain. Most DVAs are benign. Uncommonly, DVAs can become symptomatic, leading to a variety of different pathologies. DVAs can vary significantly in size, location, and angioarchitecture, and imaging evaluation of symptomatic developmental venous anomalies requires a systematic approach. In this review, we aimed to provide neuroradiologists with a succinct overview of the genetics and categorization of symptomatic DVAs based on the pathogenesis, which forms the foundation for a tailored neuroimaging approach to assist in diagnosis and management.

Lesion probability map in cerebral vein thrombosis due to Behçet's disease.

AIM: Behçet's disease (BD) is a multisystemic inflammatory disease. Cerebral venous sinus thrombosis (CVST) is the second most common form of neuro-BD after parenchymal central nervous system involvement. The purpose of this study was to construct flow-void probability maps of patients with CVST with and without BD to visually illustrate the impacted cerebral venous sinuses, to compare the subgroups of patients, and investigate the effect of thrombus localization on clinical findings. METHODS: Seventeen patients with a diagnosis of BD-related CVST (CVST-BD) and 23 patients with a diagnosis of CVST related to other etiologies (CVST-O) were included. We collected data including gender, age at onset of BD and CVST, presenting symptoms, neurological findings, and the etiology. High-resolution magnetic resonance venographies obtained during CVST were used to mark and digitalize thrombosed areas. Thrombus probability and subtraction maps were created to reveal the differences between the subgroups. RESULTS: Remarkably, all patients with CVST-BD had thrombosis in the transverse sinus (TS). However, TS was affected in 73.9% of the CVST-O patients (17/17 in CVST-BD vs 17/23 in CVST-O, P = .03). Thrombosis developed mostly in the superior sagittal sinus (SSS) and TS in the CVST-O group (11/23, 47.8% and 17/23, 73.9%, respectively). The frequency of SSS thrombosis tended to be higher in the CVST-O (47.8% vs 23.5%, P = .19). CONCLUSION: Venous infarction and hemorrhage were less common in patients with CVST-BD. The only clinical symptom in most of the CSVT patients with BD was headache due to elevated intracranial pressure. TS thrombosis was more common in patients with BD.

Diagnosis and Treatment of a Dural Arteriovenous Fistula Involving the Superior Petrosal Vein.

OBJECTIVE: A dural arteriovenous fistula involving the superior petrosal vein (SPV DAVF) is an extremely rare condition. Therefore, its clinical presentation, imaging characteristics, treatment methods, and risk factors remain unclear. In this study, we discuss and analyze the aforementioned features of an SPV DAVF. METHODS: We retrospectively reviewed 30 patients with SPV DAVFs, with a 1-year follow-up rate of 96.67% (29 of 30). The neurological function of the patients was assessed using the modified Aminoff-Logue scale and the modified Rankin Scale score. The risk factors before and after treatment were established using univariate and multivariate logistic regression analyses. Additionally, treatments involving 3 distinct SPV DAVF drainage patterns were presented. RESULTS: Of the 30 patients, 24 were men (80.0%). Besides, the angiography images were reexamined 12 months after surgery. Univariate analyses indicated that the extent of edema (odds ratio 1.889, 95% confidence interval 1.132-3.154) and the number of draining veins (≤2) (odds ratio 10.833, 95% confidence interval 1.961-59.834) were risk factors for pretreatment modified Rankin Scale score ≥3. However, multivariate analyses revealed no statistically significant differences (P = 0.051, P = 0.055). Following the multivariate analyses, steroid pulse (odds ratio 12.153 95% confidence interval 1.080-136.772) was found to be the only significant risk factor for post-treatment difference between pretreatment and 1-year follow-up modified Rankin Scale score ≥2. CONCLUSIONS: A DAVF with SPV drainage is an uncommon type of intracranial vascular malformation. Most lesions involve the brain stem or high cervical spinal cord, thereby posing a higher risk of disability or death. Moreover, neuronal damage from persistent venous hypertension is permanent. Therefore, precise diagnosis and timely treatment are key to a good patient prognosis.

Age related increase in internal jugular vein size parallels temporal development of periventricular white matter hyperintensities.

Age-related white matter hyperintensities are associated with cognitive impairment and dementia. Venous insufficiency has recently been proposed as a potential mechanism for the development of periventricular white matter hyperintensities based on the neuroanatomic distribution. The current study assesses age related changes of the internal jugular veins and its association with white matter hyperintensities. A retrospective study was performed assessing patients with computed tomography angiography (CTA) and magnetic resonance imaging (MRI) within a 4-week window. The size of the internal jugular veins, straight sinus, vein of Galen and internal cerebral veins were measured on the CT angiography. A normalized neck venous ratio was developed. Burden of white matter hyperintensities were quantified on MRI using periventricular/deep Fazekas scores. Association was assessed using correlation analysis and multrivariate linear modeling, and differences between groups were assessed using t test, ANOVA or Kruskal-Wallis test, using p < 0.05 for significance. One hundred eighty-two patients were included with a mean age of 65.2 ± 16.8 (51.6% females). Age was correlated with the normalized neck venous ratio (rs  = 0.25, p < 0.001), and, with both, the periventricular Fazekas (rs  = 0.63, p < 0.001) and the deep Fazekas (rs  = 0.57, p < 0.001) grades. The periventricular Fazekas score was positively correlated with the normalized neck venous ratio (rs  = 0.21, p = 0.003), but not significant on multivariate analysis accounting for age. The internal jugular veins demonstrate age related increase in size, paralleling the progression of periventricular white matter hyperintensities. Age remains the strongest predictor of white matter hyperintensities. Further work is needed to evaluate any causal role of venous changes on white matter hyperintensities.

Dilatation of the bridging cerebral cortical veins in childhood hydrocephalus suggests a malfunction of venous impedance pumping.

Dogs with a naturally occurring form of hydrocephalus have an elevated transmural venous pressure leading to cortical vein dilatation. The purpose of this study is to discover if there is vein dilatation in childhood hydrocephalus and to estimate the pressure required to maintain any enlargement found. Children with hydrocephalus between the ages of 4 and 15 years were compared with a control group. Magnetic resonance venography (MRV) and flow quantification were performed. The arterial inflow, sagittal sinus and straight sinus venous outflow were measured and the outflow percentages compared to the inflow were calculated. The cross-sectional area of the veins were measured. There were a total of 18 children with hydrocephalus, compared to 72 age and sex matched control MRV's and 22 control flow quantification studies. In hydrocephalus, the sagittal sinus venous return was reduced by 12.9%, but the straight sinus flow was not significantly different. The superficial territory veins were 22% larger than the controls but the vein of Galen was unchanged. There is evidence of a significant increase in the superficial vein transmural pressure in childhood hydrocephalus estimated to be approximately 4 mmHg. An impedance pump model is suggested to explain these findings.

Occipito-transtentorial approach for falcotentorial meningiomas: how I do it.

BACKGROUND: Falcotentorial meningiomas are rare tumors that arise at the junction of the dural folds of the tentorium and falx cerebri, at the junction of the vein of Galen with the straight sinus with possible extensions along the course of the straight sinus. Surgery of falcotentorial meningiomas remains challenging due to the intimate neurovascular relationships in the posterior incisural space. METHODS: We describe the key steps of the occipito-transtentorial approach for falcotentorial meningiomas with a video illustration. The surgical anatomy is described along with the advantages and limitations of this approach. CONCLUSION: The occipito-transtentorial approach offers good surgical exposure and outcomes in carefully selected patients harboring falcotentorial meningiomas. Precise understanding of the relationship between the tumor and the internal cerebral veins, basal veins, and vein of Galen should be thoroughly analyzed as these structures may be infiltrated or displaced.

A clinico-radiological study of deep cerebral venous thrombosis.

PURPOSE: Isolated deep cerebral venous thrombosis (DCVT) may have different presentation and outcome compared to DCVT with additional sinus thrombosis. We compare clinico-radiological findings and outcomes of patients with isolated DCVT with those having additional sinus thrombosis. METHODS: Forty-one DCVT patients with or without additional sinus thrombosis were included. Deep CVT was diagnosed if there was thrombosis of straight sinus, vein of Galen, internal cerebral vein, or basal vein of Rosenthal on MR venography (MRV). Isolated DCVT patients were classified as Group A and those with additional sinus thrombosis as Group B. The clinical features, risk factors, MRI findings, and outcomes at 1, 3, and 6 months were compared between Groups A and B. RESULTS: Median age was 28 years, and 22 (54%) were females. Eight (19.5%) patients were in Group A and 33 (80.5%) in Group B. Group B patients had shorter duration of illness (7 vs 30 days; p = 0.01), frequent vomiting [25 (75.7%) vs 2 (25%); p = 0.01], and papilledema [13 (39%) vs 0 (0%); p = 0.04]. Risk factors were comparable. MRI revealed bilateral thalamic [5 (62.5%) vs 6 (18.2%)] and basal ganglia [(4 (50%) vs 6 (18.2%)] lesions more frequently in Group A. At 1 month, 2 (6%) patients died in Group B and none in Group A, and 24 had good outcome (50% Group A and 60.6% in Group B). At 3 months, 30 had good outcome (62.5% Group A and 80.6% in Group B). Improvement after 3 months was negligible. CONCLUSION: Isolated DCVT is rare, and additional sinus thrombosis is associated with more severe illness and death. However, long-term outcomes in the survivors are similar between the two groups.

Isolated unilateral thalamic venous infarct in a toddler.

Isolated deep cerebral venous thrombosis (CVT), especially involving only the right thalamus, is one of the rarest forms of intracranial venous thrombosis in a child. The anatomy and flow patterns of the deep cerebral venous system are complex and usually, the thrombosis of the internal cerebral veins (ICV) results in thalamic infarction bilaterally. The focal infections, thalamic tumours and vascular malformations may have overlapping clinicoradiological patterns. The treating team should be able to recognise the atypical phenotypes of the deep CVT at the earliest, which can facilitate apt treatment and obviate the need for unnecessary investigations and interventions. We present a rare case of an isolated right thalamic acute venous infarct secondary to bilateral ICV thrombosis in a toddler who was successfully managed by timely diagnosis and with only conservative therapy.

Central Vein Sign Profile of Newly Developing Lesions in Multiple Sclerosis: A 3-Year Longitudinal Study.

BACKGROUND AND OBJECTIVES: The central vein sign (CVS), a central linear hypointensity within lesions on T2*-weighted imaging, has been established as a sensitive and specific biomarker for the diagnosis of multiple sclerosis (MS). However, the CVS has not yet been comprehensively studied in newly developing MS lesions. We aimed to identify the CVS profiles of new white matter lesions in patients with MS followed over time and investigate demographic and clinical risk factors associated with new CVS+ or CVS- lesion development. METHODS: In this retrospective longitudinal cohort study, adults from the NIH MS Natural History Study were considered for inclusion. Participants with new T2 or enhancing lesions were identified through review of the radiology report and/or longitudinal subtraction imaging. Each new lesion was evaluated for the CVS. Clinical characteristics were identified through chart review. RESULTS: A total of 153 adults (95 relapsing-remitting MS, 27 secondary progressive MS, 16 primary progressive MS, 5 clinically isolated syndrome, and 10 healthy; 67% female) were included. Of this cohort, 96 had at least 1 new T2 or contrast-enhancing lesion during median 3.1 years (Q1-Q3: 0.7-6.3) of follow-up; lesions eligible for CVS evaluation were found in 62 (65%). Of 233 new CVS-eligible lesions, 159 (68%) were CVS+, with 30 (48%) individuals having only CVS+, 12 (19%) only CVS-, and 20 (32%) both CVS+ and CVS- lesions. In gadolinium-enhancing (Gd+) lesions, the CVS+ percentage increased from 102/152 (67%) at the first time point where the lesion was observed, to 92/114 (82%) after a median follow-up of 2.8 years. Younger age (OR = 0.5 per 10-year increase, 95% CI = 0.3-0.8) and higher CVS+ percentage at baseline (OR = 1.4 per 10% increase, 95% CI = 1.1-1.9) were associated with increased likelihood of new CVS+ lesion development. DISCUSSION: In a cohort of adults with MS followed over a median duration of 3 years, most newly developing T2 or enhancing lesions were CVS+ (68%), and nearly half (48%) developed new CVS+ lesions only. Importantly, the effects of edema and T2 signal changes can obscure small veins in Gd+ lesions; therefore, caution and follow-up is necessary when determining their CVS status. TRIAL REGISTRATION INFORMATION: Clinical trial registration number NCT00001248. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that younger age and higher CVS+ percentage at baseline are associated with new CVS+ lesion development.

COVID-19 Vaccine-Related Thrombosis: A Systematic Review and Exploratory Analysis.

Introduction: The World Health Organization declared the coronavirus disease 2019 (COVID-19) pandemic on March 11, 2020. Two vaccine types were developed using two different technologies: viral vectors and mRNA. Thrombosis is one of the most severe and atypical adverse effects of vaccines. This study aimed to analyze published cases of thrombosis after COVID-19 vaccinations to identify patients' features, potential pathophysiological mechanisms, timing of appearance of the adverse events, and other critical issues. Materials and Methods: We performed a systematic electronic search of scientific articles regarding COVID-19 vaccine-related thrombosis and its complications on the PubMed (MEDLINE) database and through manual searches. We selected 10 out of 50 articles from February 1 to May 5, 2021 and performed a descriptive analysis of the adverse events caused by the mRNA-based Pfizer and Moderna vaccines and the adenovirus-based AstraZeneca vaccine. Results: In the articles on the Pfizer and Moderna vaccines, the sample consisted of three male patients with age heterogeneity. The time from vaccination to admission was ≤3 days in all cases; all patients presented signs of petechiae/purpura at admission, with a low platelet count. In the studies on the AstraZeneca vaccine, the sample consisted of 58 individuals with a high age heterogeneity and a high female prevalence. Symptoms appeared around the ninth day, and headache was the most common symptom. The platelet count was below the lower limit of the normal range. All patients except one were positive for PF4 antibodies. The cerebral venous sinus was the most affected site. Death was the most prevalent outcome in all studies, except for one study in which most of the patients remained alive. Discussion: Vaccine-induced thrombotic thrombocytopenia (VITT) is an unknown nosological phenomenon secondary to inoculation with the COVID-19 vaccine. Several hypotheses have been formulated regarding its physiopathological mechanism. Recent studies have assumed a mechanism that is assimilable to heparin-induced thrombocytopenia, with protagonist antibodies against the PF4-polyanion complex. Viral DNA has a negative charge and can bind to PF4, causing VITT. New experimental studies have assumed that thrombosis is related to a soluble adenoviral protein spike variant, originating from splicing events, which cause important endothelial inflammatory events, and binding to endothelial cells expressing ACE2. Conclusion: Further studies are needed to better identify VITT's pathophysiological mechanisms and genetic, demographic, or clinical predisposition of high-risk patients, to investigate the correlation of VITT with the different vaccine types, and to test the significance of the findings.

Characteristics and Management of Autoimmune Disease-Associated Cerebral Venous Sinus Thrombosis.

Cerebral venous sinus thrombosis (CVST) is a central nervous system disease characterised by thrombosis in cerebral venous or dural sinuses. Autoimmune diseases, a series of diseases caused by immune responses to autoantigens, are important causes of CVST. The most common diseases that lead to CVST are Behçet's syndrome, systemic lupus erythematosus, antiphospholipid syndrome, and Sjögren's syndrome. Each of these diseases have different clinical and imaging manifestations and treatment for CVST varies by aetiology. This review summarises the characteristics and the current management strategies for autoimmune disease-associated CVST and emphasises controversial therapeutic strategies to provide informative reference information for diagnosis and treatment. Risk factors of autoimmune antigens should not be neglected when unconventional CVST occurs, and both drugs and interventional therapy need further standardisation and discussion with more prospective clinical studies.

Incidence Rates and Case-Fatality Rates of Cerebral Vein Thrombosis: A Population-Based Study.

Background and Purpose: Cerebral vein thrombosis (CVT) incidence is estimated to be >10 per 1 000 000 per year. Few population-based studies investigating case-fatality rates (CFRs) and pyogenic/nonpyogenic CVT incidence are available. We assessed trends in CVT incidence between 2002 and 2012, as well as adjusted in-hospital CFRs and incidence of hospital admissions for pyogenic/nonpyogenic CVT in a large Northwestern Italian epidemiological study. Methods: Primary and secondary discharge diagnoses of pyogenic/nonpyogenic CVT were identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes 325, 671.5, and 437.6. Age, sex, vital status at discharge, length of hospital stay, and up to 5 secondary discharge diagnoses were collected. Concomitant presence of intracerebral hemorrhage (ICH) was registered, and comorbidities were assessed through the Charlson comorbidity index. Results: A total of 1718 patients were hospitalized for CVT (1147 females­66.8%; 810 pyogenic and 908 nonpyogenic CVT, 47.1% and 52.9%, respectively), with 134 patients (7.8%) experiencing a concomitant ICH. The overall incidence rate for CVT was 11.6 per 1 000 000 inhabitants with a sex-specific rate of 15.1 and 7.8 per 1 000 000 in females and males, respectively. CVT incidence significantly increased in women during time of observation (P=0.007), with the highest incidence being at 40 to 44 years (27.0 cases per 1 000 000). In-hospital CFR was 3%, with no difference between pyogenic/nonpyogenic CVT. Patients with concomitant ICH had a higher in-hospital CFR compared with patients without ICH (7.5% versus 2.7%; odds ratio, 2.96 [95% CI, 1.45­6.04]). In-hospital CFR progressively increased with increasing Charlson comorbidity index (P=0.003). Age (odds ratio, 1.03 [95% CI, 1.02­1.05]), Charlson comorbidity index ≥4 (odds ratio, 4.33 [95% CI, 1.29­14.52]), and ICH (odds ratio, 3.05 [95% CI, 1.40­6.62]) were independent predictors of in-hospital mortality. Conclusions: In a large epidemiological study, CVT incidence was found to be comparable to the one registered in population-based studies reported after the year 2000. CVT incidence increased among women over time. In-hospital CFR was low, but not negligible, in patients with concomitant ICH. Age, ICH, and a high number of comorbidities were independent predictors of in-hospital mortality. Pyogenic CVT was not a predictor of in-hospital CFR, although its high proportion was not confirmed by internal validation.

Quantitative susceptibility mapping in ischemic stroke patients after successful recanalization.

Quantitative susceptibility mapping (QSM) is a novel processing method for gradient-echo magnetic resonance imaging (MRI). Higher magnetic susceptibility in cortical veins have been observed on susceptibility maps in the ischemic hemisphere of stroke patients, indicating an increased oxygen extraction fraction (OEF). Our goal was to investigate susceptibility in veins of stroke patients after successful recanalization in order to analyze the value of QSM in predicting tissue prognosis and clinical outcome. We analyzed MR images of 23 patients with stroke due to unilateral middle cerebral artery (MCA)-M1/M2 occlusion acquired 24-72 h after successful thrombectomy. The susceptibilities of veins were obtained from QSM and compared between the stroke territory, the ipsilateral non-ischemic MCA territory and the contralateral MCA territory. As outcome variables, early infarct size and functional disability (modified Rankin Scale, mRS) after 3-5 months was used. The median susceptibility value of cortical veins in the ischemic core was 41% lower compared to the ipsilateral non-ischemic MCA territory and 38% lower than on the contralateral MCA territory. Strikingly, in none of the patients prominent vessels with high susceptibility signal were found after recanalization. Venous susceptibility values within the infarct did not correlate with infarct volume or functional disability after 3-5 months. Low venous susceptibility within the infarct core after successful recanalization of the occluded vessel likely indicates poor oxygen extraction arising from tissue damage. We did not identify peri-infarct tissue with increased susceptibility values as potential surrogate of former penumbral areas. We found no correlation of QSM parameters with infarct size or outcome.

Estimation of the Morphofunctional Status of the Brain in Hypertensive Wistar Rats Using Diffusion-Weighted MRI.

Morphofunctional changes of the brain tissues of Wistar rats were studied based on the development of a multifactor cardiovasorenal model of arterial hypertension using MRI. An increase of the signal on the diffusion brain maps was recorded in 3 months, which indicated fluid accumulation in the intra- and extracellular space of the brain tissue. The data characterize the development of the pathogenetic mechanism of the hypervolemic variant of experimental arterial hypertension. The development of endothelial dysfunction in the brain vessels was manifested by predominance of abnormal constrictor reactions. In 6 months after arterial hypertension simulation, structural changes in the brain developed, such as leukoareosis, cystic encephalomalacia with dilated cerebrospinal fluid spaces and limited blood supply to brain tissue in the basins of the large cerebral arteries.

Abnormal development of cerebral arteries and veins in offspring of experimentally preeclamptic rats: Potential role in perinatal stroke.

Preeclampsia, a hypertensive disorder of pregnancy, complicates up to 10 % of all pregnancies and increases the risk for perinatal stroke in offspring. The mechanism of this increase is unknown, but may involve vascular dysfunction. The goal of this study was to evaluate the effect of experimental preeclampsia (ePE) on cerebrovascular function in offspring to eludciate a possible mechanism for this association. Dams were fed a high cholesterol diet beginning on day 7 of gestation to induce experimental preeclampsia. Middle cerebral arteries (MCA) and the Vein of Galen (VoG) were isolated from pups from ePE dams and compared to pups from normal pregnant (NP) dams at postnatal days 16, 23, and 30 and studied pressurized in an arteriograph chamber. Markers of inflammation and oxidative stress were measured in serum. Our results suggest altered structure and function in both MCA and VoG of ePE pups. We also found evidence of systemic inflammation and oxidative stress in ePE pups. These findings provide a potential link between preeclampsia and the occurrence or severity of perinatal stroke.

Dilation of Brain Veins and Perivascular Infiltration by Glioblastoma Cells in an In Vivo Assay of Early Tumor Angiogenesis.

The cranial window (CW) technique provides a simple and low-cost method to assess tumor angiogenesis in the brain. The CW combined with histology using selective markers for tumor and endothelial cells can allow a sensitive monitoring of novel antiangiogenesis therapies in preclinical models. The CW was established in cyclosporine immunosuppressed rats that were stereotactically grafted with fluorescent U87MG glioblastoma cells. One to 3 weeks after grafting, brain vasculature was visualized in vivo and assessed by immunofluorescence microscopy using antibodies against endothelial and smooth-muscle cells and blood brain barrier. At 1-2 weeks after grafting, the CW reliably detected the hypertrophy of venous-venous anastomoses and cortical veins. These structures increased highly significantly their pregrafting diameter. Arterialized veins and hemorrhages were seen by three weeks after grafting. Immunofluorescence microscopy showed significant branching and dilation of microvessels, particularly those surrounded by tumor cells. Mechanistically, these changes lead to loss of vascular resistance, increased venous outflow, and opening of venous-venous anastomoses on the cortical surface. Data from the present study, namely, the hypertrophy of cortical venous-venous anastomoses, microvessel branching, and dilation of the microvessels surrounded by tumor cells, indicate the power of this in vivo model for the sensitive monitoring of early tumor angiogenesis.