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The endothelial-lined dural venous sinuses collect blood from the brain, meninges, and calvaria and drain it to the internal jugular veins. The adult drainage pathway of the venous sinuses confluent is commonly via the transverse and sigmoid sinuses to the jugular bulb. The occipital (OS) and marginal (MS) sinuses are well-represented before birth, in most cases. During a retrospective study of the computed tomography angiograms of a 64 y.o. female was found a rare combination of variants of the posterior fossa sinuses. The confluence of the dural venous sinuses was rhomboidal and drained superiorly the superior sagittal sinus, and inferiorly a well-represented occipital sinus (OS). The transverse sinuses were aplastic, on the right side, and hypoplastic on the opposite side. The OS further drained into the MS which, on each side, emptied into the respective jugular bulb. On each side a condylar vein left the junction of the sigmoid sinus and jugular bulb. Such posterior fossa drainage, exclusively on the OS-MS pathway, should be kept in mind when transections of the venous sinuses are intended during neurosurgical approaches of the foramen magnum. The OS-MS drainage is rather a persisting fetal pattern. The bilateral anatomical exclusion of the transverse sinuses is an added condition to spare the OS and MS.

Idiopathic intracranial hypertension (IIH) is increased intracranial pressure without a known cause. Dural venous sinus stenting (DVSS) is a relatively new intervention for treatment of IIH refractory to medical therapy and lifestyle modifications. In this review, we outline various hypotheses of IIH pathogenesis and describe the role of venous sinus stenosis and the technical details of DVSS. We also present a summary and critique of the available evidence describing the outcomes of DVSS in IIH and review the evidence-based guidelines for this procedure. We conclude that, although many studies have shown generally favorable outcomes of DVSS in patients with IIH, most have serious limitations, the most common one being paucity of pre- and postprocedure ophthalmological data. Thus, there is not enough available evidence to conclude whether DVSS is an effective procedure for treatment of IIH. We also present the most commonly used indications for DVSS as described in the literature and stress the importance of neuro-ophthalmological assessment before and after the procedure to monitor response and potential complications.

OBJECTIVE: Venous hypertension associated with a primitive basal vein of Rosenthal (BVR) has been noted as the most likely cause of idiopathic subarachnoid hemor-rhage (iSAH). Other types of venous drainage variations have been scarcely studied but may further explain the cases not associated with a BVR anomaly. Our aim was to investigate if dural venous sinus (DVS) anomalies are related with iSAH. - METHODS: A total of 76 patients diagnosed with iSAH were identified from a prospectively maintained database and their angiographic findings compared with 76 patients diagnosed with aneurysmal subarachnoid hemorrhage. -RESULTS: On top of the BVR variations, our data showed a higher prevalence of transverse sinus hypoplasia (47.4% vs. 28.9%; P = 0.019), superior petrosal sinus hypoplasia (32.9% vs. 13.2%; P = 0.003), and clival plexus hyperplasia (65.8% vs. 43.4%; P = 0.005) in patients with iSAH. Analyzing by total number of angiograms, the iSAH group showed also a higher prevalence of inferior petrosal sinus hyperplasia (36.2% vs. 25%; P = 0.003). Of the patients with iSAH without a primitive BVR, 84% harbored double dagger 1 peri-mesencephalic DVS variation and the overall number of venous drainage variations was significantly higher in patients with iSAH. CONCLUSIONS: In addition to the well-documented BVR anomalies, there seems to be a significant relationship of other DVS variations in patients with iSAH. Transverse si-n us hypoplasia, superior petrosal sinus hypoplasia, inferior petrosal sinus hyperplasia, and clival plexus hyperplasia were significantly more frequent in patients with iSAH. The presence of double dagger 3 of those variations would increase the suspicion of a nonaneurysmatic subarachnoid hemorrhage and could help avoid a second angiogram.

Introduction: Although still considered quite harmless, nonpowder guns (NPG) may cause severe head injuries in children. We present the case of a depressed skull fracture with superior sagittal sinus involvement following NPG injury. Decision-making and surgical management are discussed, and the current literature concerning NPG-related pediatric head injuries is reviewed. Case Presentation: A 4-year-old boy hit by a compressed-air rifle came to our center. CT scan showed a depressed skull fracture of the occipital bone on the midline and intracranial penetration of some fragments of the pellet. CT angiography documented a compression of the superior sagittal sinus without thrombosis. Soon after hospital admission, the patient showed deterioration of the neurological status suggesting intracranial hypertension. Surgery was performed with fracture elevation, removal of metal fragments, and wound debridement. The patient had a full recovery without subsequent neurological deficits. Discussion/Conclusion: Modern airguns may produce severe penetrating head injuries in children. Parents and physicians should be aware of the danger of NPG. Depressed skull fracture and dural venous sinus involvement can occur, and even a stable neurological condition may worsen. In such instances, a thorough preoperative assessment including vascular imaging is mandatory. The surgical risk is not negligible due to the possible injury of the sinus wall and subsequent intraoperative bleeding. This has to be weighted against potential complications of the penetrating injury, such as infection, sinus thrombosis, and intracranial hypertension. Our case suggests that prompt surgical treatment can be a safe and effective option.

Background The veins and dural venous sinuses of the skull base are important to understand in terms of imaging findings, diagnoses, and surgery. However, to date and to the best of our knowledge, the transosseous veins of the petrous part of the temporal bone have not been studied. Methods Ten latex-injected adult cadaveric specimens (20 sides) were dissected to identify the intraosseous and transosseous veins. The petrous part of the temporal bone was drilled away, and the petrous part of the internal carotid artery and the veins of the middle and posterior cranial fossa adjacent to the petrous part of the temporal bone were exposed. Results Transosseous veins traveling through the petrous part of the temporal bone were identified on all 20 sides. In general, these were most concentrated near the anterior and posterior parts of the petrous part of the temporal bone. Most traveled more or less vertically from the petrous ridge and related superior petrosal sinus internally through the petrous part of the temporal bone toward the inferior petrosal sinus or horizontally, uniting the veins of the floor of the middle cranial fossa with the veins of the posterior cranial fossa. These transosseous veins connected the veins in the middle cranial fossa with the veins of the posterior cranial fossa. Most (70%) of these transosseous veins were also found to have small connections to the internal carotid venous plexus. Conclusions To the best of our knowledge, previous studies have not reported on transosseous veins of the temporal bone or described their anatomy of connecting the veins of the middle and posterior cranial fossae.

Knowledge of the variant anatomy of the intradural venous sinuses is important to anatomists and clinicians alike. Herein, we report a cadaveric case of the rare venous sinus of Kelch, which some have believed is a remnant of the cranio-orbital sinuses. To our knowledge, only one other cadaveric case has been reported in the extant medical literature. Clinically, knowledge of such a variant venous sinus can minimize misdiagnoses such as when anatomical variations are noted on imaging. Surgically, such an understanding can avoid intraoperative complications such as iatrogenic hemorrhage.

Background: Although most traumatic epidural hematomas are secondary to arterial injuries, particularly rupture of the middle meningeal artery, around 9.7% of cases are associated with dural venous sinus injury, leading to poorer prognosis and greater complications. We report a case of a patient presenting cranial trauma with bone fracture and laceration of the transverse sinus producing epidural hematoma, and discuss the main aspects of this condition. Case description: A 47-year-old man struck by a motorcycle was admitted to the Emergency Room with a score of 15 on the Glasgow Coma Scale, evolving over 5 hours with reduced level of consciousness. A cranial CT scan was performed disclosing right parieto- occipital hyperdensity, consistent with acute epidural hematoma, and a parieto-occipital fracture line crossing the path of the ipsilateral transverse sinus. Parietal craniotomy was performed to drain the hematoma, revealing a venous sinus injury requiring immediate repair. Conclusions: This case and discussion highlight the many details and technical specificities to be taken into account by neurosurgeons when encountering intracranial hematoma caused by traumatic injury of the dural venous sinus, and which are pivotal in determining the efficacy of the treatment approach and prognosis of the patient.

Brain herniation into arachnoid granulation (BHAG) is a quite recently described controversial entity in terms of both etiology and clinical significance. It comprises a herniation of brain tissue into a presumed preexisting arachnoid granulation in dural venous sinuses, calvarium, meningeal or diploic veins. Most often described as an incidental finding in patients examined for unrelated pathologies, some BHAGs can possibly be related to headache, epilepsy or conditions with increased intracranial pressure such as idiopathic intracranial hypertension (IIH) or pseudotumor cerebri (PTC). The number of reported cases is low and there are only three more recently published observational studies on this subject with results lacking statistical significance due to relatively few BHAGs analyzed. Therefore, BHAGs still need an increased focus from both the radiologists and clinicians and more published studies and cases are necessary to help in understanding their factual meaning, clinical and treatment implications. In this article we describe three new cases of BHAGs to the literature, with patients presenting with different symptoms.

PurposeTo evaluate the anatomical variations of dural venous sinuses in children with external hydrocephalus, proposing a radiological grading of progressive anatomic restriction to venous outflow based on brain phase-contrast magnetic resonance venography (PC-MRV); to evaluate the correlation between positional plagiocephaly and dural sinuses patency; and to compare these findings with a control group to ascertain the role of anatomical restriction to venous outflow in the pathophysiology of external hydrocephalus.MethodsBrain MRI and PC MRV were performed in 97 children (76 males, 21 females) diagnosed with external hydrocephalus at an average age of 8.22 months. Reduction of patency of the dural sinuses was graded as 1 (stenosis), 2 (complete stop) and 3 (complete agenesis) for each transverse/sigmoid sinus and sagittal sinus. Anatomical restriction was graded for each patient from 0 (symmetric anatomy of patent dural sinuses) through 6 (bilateral agenesis of both transverse sinuses). Ventricular and subarachnoid spaces were measured above the intercommissural plane using segmentation software. Positional plagiocephaly (PP) and/or asymmetric tentorial insertion (ATI) was correlated with the presence and grading of venous sinus obstruction. These results were compared with a retrospective control group of 75 patients (35 males, 40 females).ResultsBoth the rate (84.53% vs 25.33%) and the grading (mean 2.59 vs mean 0.45) of anomalies of dural sinuses were significantly higher in case group than in control group. In the case group, sinus anomalies were asymmetric in 59 cases (right-left ratio 1/1) and symmetric in 22. A significant association was detected between the grading of venous drainage alterations and diagnosis of disease and between the severity of vascular anomalies and the widening of subarachnoid space (SAS). Postural plagiocephaly (39.1% vs 21.3%) and asymmetric tentorial insertion (35.4% vs 17.3%) were significantly more frequent in the case group than in the control group. When sinus anomalies occurred in plagiocephalic children, the obstruction grading was significantly higher on the flattened side (p ≤ 0.001).ConclusionDecreased patency of the dural sinuses and consequent increased venous outflow resistance may play a role in the pathophysiology of external hydrocephalus in the first 3 years of life. In plagiocephalic children, calvarial flattening may impact on the homolateral dural sinus patency, with a possible effect on the anatomy of dural sinuses and venous drainage in the first months of life.

It has been commonly accepted for a long time that the cerebrospinal fluid (CSF) drains into arachnoid granulations from the subarachnoid space to the dural venous sinus unidirectionally. However, recently, periventricular capillaries and lymphatic concepts have been introduced. The CSF moves along the perivascular space and drains into the capillary vessels or meningeal lymphatic tissues. CSF is involved in removing brain waste out of the brain. In this study, we investigated the outflow mechanism of substances in the CSF from the brain. We investigated the movement of CSF by injection of gold colloid conjugates (2, 40, and 200 nm) into the lateral ventricles of mouse fetuses and evaluated the deposition by silver stain with tissue transparency and electron microcopy. Cadaverine was also injected into the lateral ventricle to determine its movement tract. The gold particle deposition was mainly observed in the frontal skull base. Electron microscopic study showed that the gold particle deposition was observed on the choroid plexus and ependyma in the lateral ventricle and also red blood cells in the heart and liver. Two-nanometer particles were exclusively observed in the liver. Cadaverine injection study demonstrated that cadaverine was observed at the extracranial frontal skull base, choroid plexus, ependymal surface, and perivascular area in the brain white matter. The particles in the CSF were shown to move from the brain to the frontal skull base and also into the blood stream through the choroid plexus in the fetus. The outflow of particles in the CSF may be regulated by molecular size. This new information will contribute to the prevention of brain degeneration due to brain waste deposition.

Middle meningeal vessels, dural venous sinuses, and emissary veins leave imprints and canals in the endocranium, and thus provide evidence of vascular patterns in osteological samples. This paper investigates whether craniovascular morphology undergoes changes in craniosynostotic human skulls, and if specific alterations may reflect structural and functional relationships in the cranium. The analyzed osteological sample consists of adult individuals with craniosynostoses generally associated with dolichocephalic or brachycephalic proportions, and a control sample of anatomically normal adult skulls. The pattern and dominance of the middle meningeal artery, the morphology of the confluence of the sinuses, and the size and number of the emissary foramina were evaluated. Craniovascular morphology was more diverse in craniosynostotic skulls than in anatomically normal skulls. The craniosynostotic skulls often displayed enlarged occipito-marginal sinuses and more numerous emissary foramina. The craniosynostotic skulls associated with more brachycephalic morphology often presented enlarged emissary foramina, while the craniosynostotic skulls associated with dolichocephalic effects frequently displayed more developed posterior branches of the middle meningeal artery. The course and morphology of the middle meningeal vessels, dural venous sinuses, and emissary veins in craniosynostotic skulls can be related to the redistribution of growth forces, higher intracranial pressure, venous hypertension, or thermal constraints. These functional and structural changes are of interest in both anthropology and medicine, involving epigenetic traits that concern the functional and ontogenetic balance between soft and hard tissues.

To assess the efficacy of endovascular venous sinus stenting (EVSS) in treating pulsatile tinnitus (PT) caused by dural venous sinus stenosis (DVSS), and to determine whether it is an adequate remedy in cases with concurrent venous anomalies.Seventeen patients (13 female and four male) with PT due to DVSS were treated using EVSS. The trans-stenotic pressure gradient (PG) was measured before and after stenting. The effect of stenting on the tinnitus was evaluated by questioning the patients at day 0, and at 3, 6, and 9 months after stenting.Except for one patient who continued to complain of PT, all of the patients, including two with concomitant sinus diverticula, described complete resolution of the tinnitus immediately following stenting. The post-stenting PG was significantly lower than the pre-stenting PG (p0.0001). No procedure related complications occurred and no recurrence was recorded during the follow-up period.EVSS is a safe and successful treatment for PT due to DVSS even in cases with coexistent sinus diverticula.

Background Spontaneous intracranial hypotension (SIH) is characterized by positional headache caused by low CSF pressure, without any major traumatic event. Optimal treatment is still debated; epidural blood patch (EBP) is usually used after unsuccessful conservative treatment with variable efficacy and potentially severe complications. Although steroids have been reported to be beneficial, their effectiveness is still controversial, and more clinical evidence is needed. Case presentation A 37-year-old woman was admitted to the neurology department due to severe orthostatic headache with nausea over the last 5 days. No trauma history or spinal manipulation were mentioned. On arrival, neurological examination, brain CT, and laboratory investigation were normal. Intracranial hypotension was clinically suspected, and lumbar puncture revealed low opening pressure. Brain MRI demonstrated pachymeningeal gadolinium enhancement and distended and rounded dural venous sinuses, while cervicothoracic spine MRI revealed thoracic CSF leakage, leading to SIH diagnosis. The patient was treated with high-dose intravenous methylprednisolone, with complete clinical resolution within 24 h. Conclusions Our case, combined with literature evidence, supports the high-dose intravenous corticosteroids as a reasonable treatment option in selected cases, before trying EBP or surgical repair. Randomized clinical trials are needed, in order to optimize SIH patients’ outcomes.

Background Microvascular Doppler (MVD) has been widely used for the detection of arterial blood flow in the brain, especially during aneurysm clipping, vascular malformation resection, or bypass surgeries. However, the benefits obtained from early identification of intracranial sinuses and deep draining veins during tumor resection has not been reported. Methods We reviewed the clinical data and imaging from our cases and conducted a systemic review of the medical literature using PubMed and keywords. Bibliographies of each result were evaluated to determine if additional reports describing the use of MVD during tumor resection could be found. Results No reports were found in the literature where MVD was specifically used for venous identification during the resection of deep-seated brain tumors. In our patient cohort, MVD was used successfully to detect and ultimately allow immediate protection of large dural venous sinuses as well as smaller deep cerebral veins during tumor resection. Each patient developed no new venous infarcts and made a satisfactory recovery with no new postoperative neurological deficits. Conclusion MVD is a reliable tool for the intraoperative detection of intracranial venous blood flow to allow for quick identification and protection of venous structures. MVD is an additional safety measure for the patient as its accuracy in detecting venous structures is less susceptible to many of the inherent weaknesses of stereotactic neuro-navigation including the accompanying brain shift or anatomical distortion produced by long duration deep seated brain tumor resection.

BackgroundDural venous sinus injury is a rare complication of otological surgery that can lead to life-threatening sequelae, the management of which is complex and poorly described.Case reportThis paper describes the case of a 40-year-old female who underwent routine right myringoplasty complicated by sigmoid sinus laceration. The patient subsequently developed right-sided lateral sinus thrombosis leading to fulminant intracranial hypertension. The patient underwent successful emergency management by surgical reconstruction of the sigmoid sinus, followed by endovascular thrombolysis, catheter balloon angioplasty and endovascular stenting.ConclusionTorrential haemorrhage following otological procedures is uncommon and rarely requires packing of a bleeding venous sinus. This case highlights that injury to a highly dominant venous sinus can lead to venous outflow obstruction and life-threatening intracranial hypertension. To our knowledge, the development of this complication following otological surgery and its management has not been reported previously.

The incidence of dural venous sinus thrombosis (DVST) and the cerebral venous infarct have not exactly known, but DVST is closely related to the skull fracture around the venous sinus. A 56-year-old man experienced massive watery discharge after hitting on his face by a falling machine. He was alert and no cerebrospinal fluid discharge on admission. Air-density was shown on the jugular fossa in the brain computed tomography. On the 3th day of trauma, he suddenly had dyspnea and loss of consciousness and became comatose. Acute edema on medulla, pons and right cerebellar hemisphere and focal infarct on right medulla were visualized on the brain magnetic resonance imaging. And the sigmoid sinus and the jugular vein were occluded and venous circulation on the right posterior fossa was diminished on the cerebral angiography. Air-density on the sinus may be an indicator into developing venous thrombosis and brainstem venous infarct could be followed by the DVST round the jugular bulb.

Thymomas are the most common primary tumours of the anterior mediastinum. While intrathoracic disease progression through local invasion is well described in the literature, extrathoracic extension of disease is uncommon and intracranial metastases have seldom been reported. We present a case of extensive dural venous sinus tumour thrombus in a patient with metastatic invasive thymoma.

Objective: The objective of this study was to analyze the main source of bleeding and operative findings in an extradural hematoma (EDH). Material and Methods: A descriptive study was conducted at the Neurosurgery Department of Hayatabad Medical Complex Peshawar from March 2017 to April 2020.The study included 550 patients that met the criteria of inclusion well. Demographic profile, location of Extra-Dural hematoma, the source of bleeding, presence or absence of skull fracture and per operative findings were documented in structured proforma. Results: 69% were male and 31% were female patients. The middle age group of 21 – 40 years mostly affected. Rupture or laceration of middle meningeal artery was the communal source of bleeding in 355 (64.5%) patients, followed by fracture bone in 285 (51.8%) of patients and dural venous sinus in 70 (12.7%) of patients. Preoperative findings in our study were linear skull fracture in 250 (45.4.0%), underlying contusion in 165 (30%), and contralateral hematoma in 70 (12.7%) of cases. Conclusion: Rupture or laceration of a Middle meningeal artery (MMA) was the most communal source of bleeding in extradural hematoma. Therefore, per-operative cauterization of this vessel is important to prevent the chances of re-bleed and re-do surgeries.

Brain herniation into a dural venous sinus is a rare entity of unknown clinical significance without a clear relationship to raised intracranial pressure. There are yet to be detailed reports of interventional neuroradiology procedures involving sinus stenting across brain herniations. The authors of this paper present the first case of a stent placed across a large brain herniation into the transverse sinus in a patient with a tectal plate lesion and features of chronically raised intracranial pressure. This case demonstrates objective resolution of papilloedema and venous sinus pressure gradient at six months without complication.

Systemic pulse corticosteroid therapy is used widely in the treatment of pemphigus vulgaris. Dural venous sinus thrombosis as a complication of pulse therapy has not been reported in the literature. A middle-aged female with pemphigus vulgaris was started on monthly pulse dexamethasone therapy with daily azathioprine as an adjuvant. After two pulse therapies, she developed throbbing headache, which on further evaluation was determined to be due to dural venous thrombosis. Other causes of dural venous thrombosis were excluded. Pulse therapy was stopped and other medications were started. The headache subsided within two weeks of stopping pulse therapy. Corticosteroids may play the role of a procoagulant in producing cerebral venous sinus thrombosis. Herein, we report a rare case of dural venous sinus thrombosis due to pulse steroid therapy in pemphigus vulgaris.

Cerebral venous sinus thrombosis (CVST) is presence of a blood clot in the dural venous sinuses. This is a rare, but dangerous condition. CSVT is characterized by a highly variable clinical spectrum, difficult diagnosis, variable etiologies and prognosis. The International Study on Cerebral Vein and Dural Sinus Thrombosis (ISCVT) determined the frequency of the sites of SCVT. The aim of this case study was to show the clinical presentation, the examination we made, the therapy that was ordinated and the outcome of the treatment. Case study: A 14-year-old male teenager was admitted to the University Clinic for Neurosurgery in Skopje with GCS 10, accompanied with tonic-clonic epileptic seizures. CT examinations by systems were made, and during the time of recording the patient was given Dormicum 2mg overall dose. CT scan of the brain showed hyperdense zones formation around superior sagittal sinus (SSS), the rest of the medical finding was normal. We ran laboratorytests and the test for hemostasisshowed deviation from the normal range. With the ordinated therapy the clinical condition of the patient drastically improved. He was discharged home 12 days after the admission. He was given a recommendation for further check-ups by a transfusiologist and regular visits to our clinic. Occlusion of the cerebral veins and dural venous sinuses may occur on the basis of local trauma, neoplasm or infection. Primary aseptic thrombosis may involve either cerebral veins or dural venous sinuses, or both in combination. The clinical picture and the prognosis of intracranial venous thrombosis probably depend largely on the location, extent, and rapidity of development of the venous occlusion. Conclusion: Superior sagittal sinus thrombosis is a condition that can be manifested with diverse and many symptoms and signs, which often can start unexpectedly and can be life-threatening.

Background Cerebrovascular injury (CVI) is a potentially devastating complication of gunshot wounds to the head (GSWH), with yet unclear incidence and prognostic implications. Few studies have also attempted to define CVI risk factors and their role in patient outcomes. We aimed to describe 10 years of CVI from GSWH and characterize these injury patterns. Methods Single-institution data from 2009 to 2019 were queried to identify patients presenting with dural-penetrating GSWH. Patient records were reviewed for GSWH characteristics, CVI patterns, management, and follow-up. Results Overall, 63 of 297 patients with GSWH underwent computed tomography angiography (CTA) with 44.4% showing CVI. The middle cerebral artery (22.2%), dural venous sinuses (15.9%), and internal carotid artery (14.3%) were most frequently injured. Arterial occlusion was the most prominent injury type (22.2%) followed by sinus thrombosis (15.9%). One fifth of patients underwent delayed repeat CTA, with 20.1% showing new/previously unrecognized CVI. Bihemispheric bullet tracts were associated with CVI occurrence (P = 0.001) and mortality (P = 0.034). Dissection injuries (P = 0.013), injuries to the vertebrobasilar system (P = 0.036), or the presence of ≥2 concurrent CVIs (P = 0.024) were associated with increased risk of mortality. Of patients with CVI on initial CTA, 30% died within the first 24 hours. Conclusions CVI was found in 44.4% of patients who underwent CTA. Dissection and vertebrobasilar injuries are associated with the highest mortality. CTA should be considered in any potentially survivable GSWH. Longitudinal study with consistent CTA use is necessary to determine the true prevalence of CVI and optimize the use of imaging modalities.

Background: The dural venous sinuses (DVS), in general, are frequently asymmetrical and display far more anatomical variations than arterial systems. A comprehensive study of the anatomy and variants of the DVS can help surgeons in the preoperative evaluation and management as well as minimizing possible complications in the following treatment. Methods: The current review was designed to provide a general overview of the normal anatomy and notable variants of the cerebral venous system as surveyed from the available literature. The pros and cons of different multimodal imaging methods for investigating DVS are also outlined. Finally, cases of various pathological entities are illustrated from our clinical practice. Conclusion: There are many anatomical variations and lesions involving the DVS. MRI examination can provide essential information both on anatomical variation and morphological or functional change of the offending DVS in most circumstances. Multimodal non-invasive venography protocols may become a feasible alternative to the classical digital subtraction angiography and would improve the diagnostic accuracy in future studies.

Cerebrospinal fluid (CSF) is produced by the choroid plexuses within the ventricles of the brain and circulates through the subarachnoid space of the skull and spinal column to provide buoyancy to and maintain fluid homeostasis of the brain and spinal cord. The question of how CSF drains from the subarachnoid space has long puzzled scientists and clinicians. For many decades, it was believed that arachnoid villi or granulations, outcroppings of arachnoid tissue that project into the dural venous sinuses, served as the major outflow route. However, this concept has been increasingly challenged in recent years, as physiological and imaging evidence from several species has accumulated showing that tracers injected into the CSF can instead be found within lymphatic vessels draining from the cranium and spine. With the recent high-profile rediscovery of meningeal lymphatic vessels located in the dura mater, another debate has emerged regarding the exact anatomical pathway(s) for CSF to reach the lymphatic system, with one side favoring direct efflux to the dural lymphatic vessels within the skull and spinal column and another side advocating for pathways along exiting cranial and spinal nerves. In this review, a summary of the historical and contemporary evidence for the different outflow pathways will be presented, allowing the reader to gain further perspective on the recent advances in the field. An improved understanding of this fundamental physiological process may lead to novel therapeutic approaches for a wide range of neurological conditions, including hydrocephalus, neurodegeneration and multiple sclerosis.

BACKGROUND AND PURPOSE: Dural venous sinus stenosis has been associated with idiopathic intracranial hypertension and isolated venous pulsatile tinnitus. However, the utility of characterizing stenosis as intrinsic or extrinsic remains indeterminate. The aim of this retrospective study was to review preprocedural imaging of patients with symptomatic idiopathic intracranial hypertension and pulsatile tinnitus, classify the stenosis, and assess a trend between stenosis type and clinical presentation while reviewing the frequencies of other frequently seen imaging findings in these conditions. MATERIALS AND METHODS: MRVs of 115 patients with idiopathic intracranial hypertension and 43 patients with pulsatile tinnitus before venous sinus stent placement were reviewed. Parameters recorded included the following: intrinsic or extrinsic stenosis, prominent emissary veins, optic nerve tortuosity, cephalocele, sella appearance, poststenotic fusiform enlargement versus saccular venous aneurysm, and internal jugular bulb diverticula. χ2 cross-tabulation statistics were calculated and recorded for all data. RESULTS: Most patients with idiopathic intracranial hypertension (75 of 115 sinuses, 65%) had extrinsic stenosis, and most patients with pulsatile tinnitus (37 of 45 sinuses, 82%) had intrinsic stenosis. Marked optic nerve tortuosity was more common in idiopathic intracranial hypertension. Cephaloceles were rare in both cohorts, with an increased trend toward the presence in idiopathic intracranial hypertension. Empty sellas were more common in idiopathic intracranial hypertension. Cerebellar tonsils were similarly located at the foramen magnum level in both cohorts. Saccular venous aneurysms were more common in pulsatile tinnitus. Internal jugular bulb diverticula were similarly common in both cohorts. CONCLUSIONS: In this cohort, most patients with idiopathic intracranial hypertension had extrinsic stenosis, and most patients with pulsatile tinnitus had intrinsic stenosis. Awareness and reporting of these subtypes may reduce the underrecognition of potential contributory stenoses in a given patient’s idiopathic intracranial hypertension or pulsatile tinnitus.

Background: Idiopathic intracranial hypertension (IIH), previously known as pseudotumor cerebri, is a disease characterized by elevation of intracranial tension with no apparent cause e.g. space occupying lesion or ventricular pathway obstruction. Patients usually complain of headache and sometimes burring of vision. It is believed that impaired drainage of the cerebrospinal fluid (CSF) from the dural venous sinuses and decrease spinal fluid absorption or increased secretion contribute to the development of IIH. As the optic nerve is covered by meninges and surrounded by CSF, the elevated pressure is inevitably transmitted to the nerve and can cause damage. Objective: To assess the accuracy of different MRI findings in the early diagnosis of idiopathic intracranial hypertension to achieve better prognosis. Patients and methods: twenty patients and ten controls were enrolled in the study and underwent ophthalmological tests, lumbar punctures analysis for pressure, MRI study of the brain and orbit with IV contrast administration and MR venography. Results: Six signs were analyzed from which intraocular optic nerve protrusion was the most specific (90%) and empty sella sign was the most sensitive (90%). There was statistically significant correlation between empty sella sign (r= 0.784; p = 0.01) and posterior globe flattening (r= 0.65; p = 0.04) with the idiopathic intracranial hypertension. Conclusion: MRI findings can be used to suggest idiopathic intracranial hypertension and increasing accuracy can be made by combining several signs.

An Intracranial dural arteriovenous fistulas (DAVF), is an abnormal direct connection (fistula) between a meningeal artery and a meningeal vein or dural venous sinus &/ cortical vein 1. When there are multiple fistulas they are termed as dural arteriovenous malformations and comprise 10-15% of all intracranial arteriovenous malformations1. Here we present a case of52yr old patient who presented to our casualty with history of sudden onset of headache, giddiness, and vomiting, followed by loss of consciousness. Neurological examination revealed impairment of consciousness, no verbal response, with left hemiparesis (E2V1M5). Bilaterally, pupils were 5mm and sluggishly reacting to light. Vitals were stable with B.P. recording of 140/80 mm of hg, and a pulse rate of 80 /min. Pre contrast CT scan showed an intraparenchymal haemorrhage with perilesional oedema in the right frontal region. CT angiography brainshoweda intracranial dural AVF with varix and adjacent intraparenchymal haemorrhage. D.S.A. revealed a Borden type III & Cognard type IV –midline dural Arteriovenous fistula in the regionofmid superior sagittal sinus and along the cerebral falx, with a large venous ectasia/varix along the anterior cerebral falx. Management: Patient underwent afronto parietal rectangular craniotomy Right posterior frontal, parasagittal engorged bunch of focal cortical veins was cauterized. Underlying haematoma was evacuated and the underlying venous ectasia/ varix identified. It was found to be thrombosed. A large draining vein was found which was clipped and any consequent brain swelling was looked for, before finally excising it in toto. Post –op period was uneventful, with the patient gradually improving in sensorium with residual hemiplegia and aphasia. Although recent developments in catheter interventionhas made it the preferred option in most of the cases, surgery is still preferred in some select cases. Keywords:Intracranial dural AV fistula, Superior sagittal sinus, Cog

Introduction: Idiopathic intracranial hypertension (IIH) is one of the most common causes of papilloedema seen by ophthalmologists and neurologists. Patients with IIH routinely undergo lumbar puncture (LP) for diagnosis. Dural venous sinus thrombosis (DVST) is a rare complication of cerebrospinal fluid pressure (CSF)-lowering procedures such as lumbar puncture and epidural and may be an intracranial complication of IIH. Case Description: A 29-year-old obese woman was diagnosed with severe idiopathic intracranial hypertension (IIH) after she presented with new-onset headache, pulsatile tinnitus and blurred vision. Magnetic resonance imaging (MRI) and venography (MRV) were normal apart from signs of intracranial hypertension. Lumbar puncture (LP) revealed an opening pressure of 40 cm of water. Due to the severity of the papilloedema and vision loss, she was referred for a ventriculoperitoneal shunt and found to have venous sinus thrombosis involving the superior sagittal sinus on the pre-operative computed tomography (CT) head 5 days after the LP. CT venography (CTV) one day later and MRV 3 days later showed significant worsening as the thrombosis extended into the deep venous system. She was started on therapeutic heparin and her symptoms and vision improved and she did not develop any neurological complications. Conclusions: DVST should be considered in IIH patients who have worsening papilloedema or symptoms of intracranial hypertension. Repeat venous imaging can prevent devastating consequences such as venous infarcts of haemorrhage in these patients.

Background We describe evolution of a developmental venous anomaly (DVA) over time in a patient with a complex intracranial vascular malformation. Case Description A 26-year-old male patient initially presented with a scalp vascular malformation and was later diagnosed to have a torcular dural arteriovenous fistula resembling a dural sinus malformation. The dural fistula increased in size over 4 years. The dural fistula also was associated with multiple complex developmental venous anomalies draining the bilateral cerebral hemispheres and cerebellum. The DVA was only faintly demonstrated on the baseline magnetic resonance imaging but appeared to increase in size and extent over time as the dural arteriovenous fistula developed more aggressive angioarchitecture features. In addition to the evolution manifestation of the DVAs, the patient developed multiple de novo cavernous malformations in the venous radicles of the DVA. Increased venous hypertension in the superficial venous system from the dural fistula likely resulted in growth of the DVAs, as they served as the primary means of venous drainage for the bilateral cerebral hemispheres. The patient also had reopening of the persistent falcine sinus, which was not present at baseline. Conclusions This would be the first reported case of growth or evolution of a DVA in association with a dural arteriovenous fistula in an adult patient and highlights the dynamic nature of both the medullary venous and dural venous sinuses of the cerebral venous system, even into adulthood.

BACKGROUND AND PURPOSE: The role of the dural venous sinus system in cerebrovascular pathology and the understanding of normal developmental patterns and sizes of the dural venous sinus system continue to expand. The purpose of this study was to review MR venograms to elucidate developmental patterns and diameters of the major dural venous sinuses from 0 to 20 years of age. MATERIALS AND METHODS: All available MR venograms of patients 0–20 years of age who presented to our institution were retrospectively reviewed. Patient age at the time of image acquisition was noted, and measurements were taken of the diameters of the major dural venous sinuses. The presence of embryonic sinuses including the persistent falcine sinus and the occipital sinus was noted. Dominance patterns of the transverse sinus system were determined. Mean diameters of each sinus were plotted as a function of age. The prevalence of persistent prenatal sinuses and transverse sinus–dominance patterns was compared across ages. RESULTS: A total of 429 MR venograms from 429 patients were reviewed. All dural venous sinuses demonstrated a maximal growth rate from 0 to 7 years of age and reached maximal diameters around 5–10 years of age. The prevalence of falcine sinuses and occipital sinuses trended downward across increasing age categories (P = .09 and

While numerous reports have demonstrated intracranial CNS anomalies associated with Klippel–Trenaunay syndrome, to our knowledge, there has not been a large consecutive study examining these anomalies. The aim of this study was to determine the spectrum of intracranial neurovascular manifestations in patients with a clinical diagnosis of Klippel–Tranaunay syndrome. Consecutive patients with a clinical diagnosis of Klippel–Trenaunay syndrome, as defined by the International Society for the Study of Vascular Anomalies, who underwent brain contrast-enhanced CT/computed tomography angiography, MRI/magnetic resonance angiography, or digital subtraction angiography at our institution from 2000 to 2019 were included. Studies were evaluated by a neuroradiologist and a senior radiology resident for the presence of cavernous malformations, developmental venous anomalies, venous sinus developmental abnormalities, craniofacial venous malformations, intraosseous venous malformations, and intracranial/extracranial venous abnormalities. Fifty patients with definite KTS were included. Thirty-four neurovascular anomalies were found in 17 patients (34.0%), including 8 with multiple anomalies. Nine patients had developmental venous anomalies (18.0%), 7 had craniofacial venous malformations (14.0), 6 had venous sinus developmental abnormalities (12.0%), 7 had intraosseous venous malformations (14.0%), and 2 had cavernous malformations (4.0%), and 9 patients had both intracranial venous abnormalities and craniofacial or calvarial findings (13.0%). Our findings demonstrate that Klippel–Trenaunay syndrome can involve a wide spectrum of intracranial neurovascular anomalies predominantly involving the venous system

Herniation of brain parenchyma outside its normal enclosure (also known as encephalocele) has long been known to occur at certain classic sites and is classified accordingly. With widespread use of modern neuroimaging, the previously unknown atypical and rare sites of encephalocele have now been identified. Brain herniation into a dural venous sinus is one such recently described entity with case reports extending only upto the earlier part of this decade. With no definite clinical symptomatology, imaging is crucial to diagnose this lesion accurately and differentiate it from the more familiar entity in this region of the brain, the arachnoid granulations. Also known as occult encephalocele, focal brain herniation into dural venous sinus has few specific imaging features and characteristic sites. We report a case of a 21-year-old man with partial seizures in whom MRI of the brain revealed focal herniation of the normal temporal lobe parenchyma into the left transverse sinus and discuss the key imaging features and pathophysiology of this entity.

Introduction Endovascular dural venous sinus stenting (DVSS) has emerged as a safe and effective therapy for idiopathic intracranial hypertension (IIH) in patients with transverse-sinus stenosis associated with an elevated mean pressure gradient (MPG). The typical antegrade approach, jugular to sigmoid to transverse, is not always technically feasible due to the degree of stenosis and other anatomic factors. To this point, there has been no reported cases of contralateral DVSS. We describe four cases of DVSS from a contralateral transverse-sigmoid sinus approach. Methods We describe 4 patients presenting with symptoms of IIH between 2019 and 2020 who we treated with contralateral transverse-sigmoid sinus stenting. Cases were reviewed for clinical data including initial presenting symptoms, devices used, other attempted IIH treatments, and follow up symptoms. Results Four female patients were identified and treated under general endotracheal anesthesia. Stenoses measured 72%, 78%, 67%, and 70% with MPGs across the transverse-sigmoid sinus of 19, 16, 9 and 13 mmHg, respectively. Post-stenting MPGs were 1, 0, 1 and 1 mmHg, respectively. Three patients had complete resolution of symptoms and 1 had partial resolution. No complications occurred. Conclusions This case series demonstrates successful transverse-sigmoid sinus stenting from the contralateral dural sinus and provides an alternative approach to DVSS in patients with IIH.

Background and Purpose: Intracranial dural arteriovenous fistulas (DAVFs) are abnormal shunts between dural arteries and dural venous sinus or cortical veins. We report our experience with endovascular therapy of primary complex DAVFs using modern embolic agents. Methods: This is a retrospective analysis of patients with DAVFs treated between 2015 and 2019. Patient demographics and technical aspects including the use of embolic agent, access to the fistula, number of treatments, occlusion rates, and complications were addressed. Angiographic treatment success was defined as complete occlusion (CO) of the DAVF. Results: Fifty patients were treated endovascularly. Median age was 61 years and 66% were men. The most common symptom was pulsatile tinnitus in 17 patients (34%). The most frequent location of the DAVF was the transverse-sigmoid sinus (40%). Thirty-six fistulas (72%) had cortical venous reflux. Nonadhesive and adhesive liquid agents were used in 92% as a single material or in combination. CO was achieved in 48 patients (96%). In 28 individuals (56%), only 1 procedure was necessary. Nonadhesive liquid agents were exclusively used in 14 patients (28%) with CO attained in every case. For CO of tentorial DAVFs, multiple sessions were more often required than at the other locations (55 vs. 14%, p = 0.0051). Among 93 procedures, the overall complication rate was 3%. The procedure-related mortality rate was 0%. Conclusion: Endovascular treatment of intracranial DAVFs is feasible, safe, and effective with high rates of CO. In more than half of the patients, the DAVF was completely occluded after a single procedure. However, in tentorial DAVFs, multiple sessions were more often required.

The dural venous sinuses exhibit considerable anatomic variation. Firm knowledge of dural venous sinus anatomy and common anatomic variants is of importance for the practicing neuroradiologist to recognize normal variants from pathologic conditions. In this article, we review dural venous sinus anatomy and present common variants through an image-based approach.Learning Objective: Review normal intracranial dural venous system anatomy and common variants.