Materiały źródłowe

• #1 Dural Arteriovenous Fistula – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK532274/

  Dural arteriovenous fistulas, sometimes referred to as dural arteriovenous malformations, are vascular abnormalities in which arteries arising from branches of the carotid or vertebral arteries drain directly into the dural leaflets of the venous sinuses. […] The main abnormality in dAVFs is a connection between the dural arteries and veins within the venous sinus wall via small vessels that are approximately 30 micrometers on average. […] In those patients with a provoking event, neovascularization is induced by a previously thrombosed dural venous sinus, typically the transverse sinus. […] Patients with idiopathic fistula usually have prior asymptomatic thrombosis of a dural venous sinus, secondary to inherited prothrombotic conditions (antithrombin, protein C deficiency, and protein S deficiency) or systemic illness or diseases producing prothrombotic conditions. […] Most dural arteriovenous fistulas have no clear origin; however, there is evidence that many are caused after a dural sinus thrombosis, trauma, infection, or prior craniotomy.

• #1 Journal of Cerebrovascular and Endovascular Neurosurgery

  https://the-jcen.org/m/journal/view.php?number=809

  While the exact mechanisms are still controversial, venous sinus thrombosis and venous hypertension have been believed to be associated with the genesis of DAVFs. […] Two etiologic hypotheses regarding to sinus thrombosis and venous hypertension have been suggested. […] Once triggered by venous hypertension and venous thrombosis, arterial feeder recruitment and development of DAVFs via neoangiogenesis might proceed.

• #1 Progress in research on intracranial multiple dural arteriovenous fistulas (Review)

  https://www.spandidos-publications.com/10.3892/br.2017.1021

  Intracranial multiple dural arteriovenous fistulas (MDAVFs) are rare lesions that are difficult to treat. The key factors involved in the development of MDAVFs remain unknown. […] While the exact pathogenesis of MDAVFs is unknown, a number of possible mechanisms are considered relevant. The first is that MDAVFs develop following recanalization of a large sinus thrombosis that involves several sinuses. The second possibility is that a pre-existing DAVF may induce sinus thrombosis or venous hypertension, resulting in a new MDAVF. The third is that MDAVFs are caused by increased angiogenic activity, which may induce the development of MDAVFs. […] At present, the pathogenesis underlying MDAVF development is not well understood, though there is a consensus that three mechanisms are possible: i) MDAVFs may develop following establishment of a sinus thrombosis involving several sinuses; ii) pre-existing DAVFs may induce sinus thrombosis or venous hypertension, resulting in the formation of MDAVFs; and iii) MDAVFs may be caused by increased angiogenic activity and technical problems that are associated with transvenous embolization.

• #1 Spinal Dural Arteriovenous Fistulas | American Journal of Neuroradiology

  http://www.ajnr.org/content/30/4/639

  This transition is classically located directly underneath the pedicle of the vertebral body, which is supplied by the injected segmental artery. […] The increase in spinal venous pressure due to arterialization diminishes the AV pressure gradient and leads to a decreased drainage of normal spinal veins and a venous congestion with intramedullary edema because the intramedullary veins and the radicular vein share a common venous outflow. […] This congestion, in turn, leads to chronic hypoxia and progressive myelopathy. […] Direct intraoperative measurement of the vascular pressure of the fistula was found to be as high as 74% of the systemic arterial pressure. […] This finding may explain why, in some patients, symptoms become worse during physical activity with a concomitant increase in arterial pressure. […] Because the lower thoracic region has relatively fewer venous outflow channels compared with the cervical region, the venous congestive edema is likely to be transmitted in a caudocranial direction throughout the spinal cord.

• #1 Mechanism of the Formation of Dural Arteriovenous Fistula – the Role of the Emissary Vein

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3287270/

  Dural arteriovenous fistula (DAVF) can be separated into two types: DAVF which drains through an affected sinus (sinus type) and DAVF with direct reflux to the cortical vein (non-sinus type). The present report attempted to clarify the mechanism of formation and development of DAVF focusing on the emissary vein (EV) hypothesis. […] First, inflammation occurs at the penetrating point of the EV on the dura due to idiopathic or secondary causes. Local inflammatory reactions induce vessel dilatation and neovascularization, and subsequently create arteriovenous (AV) connections on the arteriole level. […] Following the occlusion of drainage pathway through EV into the sinus or cortical veins may form, resulting in clinically detectable DAVF. The AV shunt then expands to the surrounding dura associated with recruitment of feeders from distant sites induced by expression of angiogenetic factors and a shift in the hemodynamic balance.

• #1 Mechanism of the Formation of Dural Arteriovenous Fistula – the Role of the Emissary Vein

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3287270/

  Previous mechanistic hypotheses focusing on sinus hypertension and sinus thromboses cannot explain the pathogenesis of non-sinus type of DAVF. […] Our theory based on inflammatory initiation affecting EV can explain both types of DAVF and subsequent development with pathological changes of the drainage route is not contradictory to the previous sinus-oriented theory.

• #1 Dural arteriovenous fistulas – Symptoms and causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/dural-arteriovenous-fistulas/symptoms-causes/syc-20364280

  Dural arteriovenous fistulas (dAVFs) are irregular connections between arteries and veins. They occur in the tough covering over the brain or spinal cord, known as the dura mater. The irregular passageways between arteries and veins are called arteriovenous fistulas, which can lead to bleeding in the brain or other serious symptoms. […] Although some dAVFs stem from known causes, most often the cause is not known. It’s thought that dAVFs involving large brain veins form when one of the brain’s venous sinuses narrows or becomes blocked. Venous sinuses are channels that route circulated blood from the brain back to the heart. […] Most dural arteriovenous fistulas (dAVFs) have no clear origin. But some result from a traumatic head injury, infection, previous brain surgery, blood clots in deep veins or tumors. […] Most experts think that dAVFs involving larger brain veins occur from the narrowing or blockage of one of the brain’s venous sinuses. The venous sinuses are channels in the brain that route circulated blood from the brain back to the heart.

• #1 Review of spinal dural arteriovenous fistulas: Challenges, diagnostics, management, and pathophysiology

  https://www.probiologists.com/article/review-of-spinal-dural-arteriovenous-fistulas-challenges-diagnostics-management-and-pathophysiology

  Several studies have tried elucidating the pathophysiology and molecular pathways that may be involved in the pathogenesis of spinal dural arteriovenous fistulas (sdAVFs), although there is no clear consensus on a specific mechanism. […] However, two case reports suggest that mutations in CCM genes (cerebral cavernous malformation genes) can also lead to pathogenesis of spinal cavernous malformations at large. […] The general principle of developing CCMs rely on the Knudsonian two-hit mechanism, which suggest the loss of one allele due to a germline mutation in all cells, followed by a second somatic mutation in certain cells, initiating CCM lesions. […] This may be applicable for sdAVFs as well. […] Regarding the CCM family at large, mutations in one of the three CCM genes can lead to loss of function of certain proteins, leading to endothelial barrier dysfunction and hyper-permeable blood vessels, causing leakage and bleeding.

• #1 Investigation of the mechanism of dural arteriovenous fistula formation induced by high intracranial venous pressure in a rabbit model | BMC Neuroscience | Full Text

  https://bmcneurosci.biomedcentral.com/articles/10.1186/1471-2202-15-101

  The causes of dural arteriovenous fistula have not been clearly defined. The aim of this study was to investigate the mechanism of dural arteriovenous fistula formation induced by high intracranial venous pressure using a rabbit model. […] The results of the experiments in our rabbit model indicate that high intracranial venous pressure is a key for dural arteriovenous fistula formation. Cerebral ischemia caused by lack of cerebral perfusion pressure plays a key role in the process that leads from high intracranial venous pressure to increased hypoxia inducible factor-1 expression and then increased vascular endothelial growth factor expression. […] High venous pressure may result from venous sinus thrombosis or congenital thrombosis. There are various opinions about how high venous sinus pressure induces DAVF and many studies have been carried out that have focused on this issue.

• #1 Progress in research on intracranial multiple dural arteriovenous fistulas (Review)

  https://www.spandidos-publications.com/10.3892/br.2017.1021

  Numerous angiogenic factors, including platelet-derived endothelial-cell growth factor, fibroblast growth factor and transforming growth factor- may also provide a conducive environment for the development of intracranial single DAVFs. […] When the first intracranial DAVF develops, the hemodynamics of the venous system in the brain is disturbed, and this may induce the development of new DAVFs, eventually resulting in the formation of metachronous-type MDAVFs. […] It has been hypothesized that the following two mechanisms are involved in this process: i) Venous drainage caused by an established DAVF may cause turbulent flow or stagnation in the distant venous sinus, resulting in thrombosis of the sinus and development of additional DAVFs; ii) venous hypertension may cause the development of a DAVF, and the elevation in sinus pressure caused by the initial DAVF may result in the formation of multiple new DAVFs at other sites.

• #1 Acute traumatic dural arteriovenous fistula of the superior sagittal sinus: illustrative case in: Journal of Neurosurgery: Case Lessons Volume 5 Issue 15 (2023) Journals

  https://thejns.org/caselessons/view/journals/j-neurosurg-case-lessons/5/15/article-CASE2392.xml

  Dural arteriovenous fistulas (dAVFs) are aberrant vascular communications between meningeal arteries and venous sinuses or cortical veins. dAVF pathogenesis is incompletely understood; however, formation likely occurs as a result of angioneogensis. […] The authors propose that the underlying pathogenesis is suggestive of direct vessel injury rather than the pathway commonly associated with this pathology. […] The pathogenesis of dAVFs is incompletely understood. It is hypothesized that they are acquired lesions that occur secondary to venous stenosis or thrombosis. This affects regional hemodynamics and increases the production of vascular growth factors, ultimately resulting in angioneogenesis. […] Trauma is thought to influence dAVF formation by creating a direct fistula between dural arteries and neighboring sinuses or cortical veins. […] This precludes the cascade of angioneogenesis classically associated with dAVFs. It likely results from direct vessel injury of the dural artery supported in this case by the overlying fracture.

• #1 Pathophysiology and classification of intracranial and spinal dural AVF

  http://the-jcen.org/journal/view.php?doi=10.7461/jcen.2022.E2021.04.001

  Histopathological examination supported the theory of venous hypertension as a pathophysiological mechanism in the development of DAVFs and increased venous congestion as a cause of neurological deterioration. […] An increased venous pressure results in a reduced arteriovenous pressure gradient, intramedullary impairment of autoregulation, and hypoxia.

• #1 Progress in research on intracranial multiple dural arteriovenous fistulas (Review)

  https://www.spandidos-publications.com/10.3892/br.2017.1021

  In addition to MDAVFs caused by acquired factors, certain intracranial MDAVFs may be congenital in origin, particularly those observed in children. […] In summary, the exact pathogenesis underlying the development of intracranial MDAVFs remains unclear, though venous sinus thrombosis, angiogenic factors, disturbed hemodynamics and congenital factors are considered to be potential causes.

• #1 Journal of Cerebrovascular and Endovascular Neurosurgery

  https://the-jcen.org/m/journal/view.php?number=809

  Dural arteriovenous fistulas (DAVFs) are pathologic shunts between pachymeningeal arteries and dural venous channel. […] The etiology and pathophysiology of DAVFs is not fully understood. […] The pathophysiology of development of lesions and neurological deterioration is different in patients with DAVF and those with intradural spinal AVMs. […] Although complex pathophysiologic mechanisms underlying the development of spinal DAVFs are yet to be clarified, meningeal venous thrombosis and trauma are implicated in the development of spinal DAVFs. […] Histopathological examination supported the theory of venous hypertension as a pathophysiological mechanism in the development of DAVFs and increased venous congestion as a cause of neurological deterioration. […] An increased venous pressure results in a reduced arteriovenous pressure gradient, intramedullary impairment of autoregulation, and hypoxia.

• #1 Dural Arteriovenous Fistula | Barrow Neurological InstituteSecond Opinion IconGroup 49Group 49

  https://www.barrowneuro.org/condition/dural-arteriovenous-fistula-davf/

  A dural arteriovenous fistula (DAVF) is a vascular anomaly formed by an abnormal connection between an artery within the tough covering of the brain (dura mater) and a vein that carries blood from the brain back to the heart. […] A DAVF can transfer high-pressure arterial blood into veins or venous sinuses that normally carry low-pressure, deoxygenated blood returning to the heart from the brain. This can cause neurological symptoms and bleeding into the brain (brain hemorrhage, or hemorrhagic stroke). […] These vascular anomalies are usually acquired, meaning they are not present from birth. In most cases, the cause is not obvious. However, DAVFs can be associated with trauma, surgery, tumors, or infection. […] The majority of DAVF have no known cause. However, certain conditions such as infection, cranial trauma, tumors, and prior surgery may make it more likely that you will develop a DAVF. Some hereditary vascular diseases are also associated with a higher rate of DAVF. […] These are DAVF that are associated with increased venous pressure or narrowing of the veins on the covering of the brain. Veins under increased pressure can rupture causing intracerebral hemorrhage.

• #1 Spinal Dural Arteriovenous Fistulas | American Journal of Neuroradiology

  http://www.ajnr.org/content/30/4/639

  Spinal dural arteriovenous (AV) fistulas are the most commonly encountered vascular malformation of the spinal cord and a treatable cause for progressive para- or tetraplegia. […] The AV shunt is located inside the dura mater close to the spinal nerve root where the arterial blood from a radiculomeningeal artery enters a radicular vein. […] The increase in spinal venous pressure leads to decreased drainage of normal spinal veins, venous congestion, and the clinical findings of progressive myelopathy. […] It is presumed that SDAVFs are acquired diseases, though their exact etiology is not known. […] The AV shunt is located inside the dura mater close to the spinal nerve root where the arterial blood from the radiculomeningeal artery (ie, the artery that supplies the nerve root and meninges but not necessarily the spinal cord) enters a radicular vein, where the latter passes the dura at the dorsal surface of the dural root sleeve in the intervertebral foramen.

• #1 :: KJR :: Korean Journal of Radiology

  https://www.kjronline.org/DOIx.php?id=10.3348/kjr.2015.16.5.1119

  Spinal dural arteriovenous fistula (SDAVF) is the most common spinal vascular malformation, however it is still rare and underdiagnosed. […] The exact etiology of SDAVF remains unclear. The majority of patients become symptomatic in middle age, suggesting that it is an acquired disease. Male predilection is also well known. […] Typically, one (sometimes multiple) feeding artery from a radiculopial artery or a dural branch of a radiculopial artery enters an intervertebral or radicular vein and forms a SDAVF within the dorsal surface of the dural root sleeve in the intervertebral foramen. […] The feeding artery 'arterializes’ the intervertebral vein, destroys the arteriovenous gradient and increases venous pressure, resulting in wall thickening and tortuosity of radial veins (also known as intramedullary veins), since intervertebral and radial veins share a common venous outflow.

• #1 Dural arteriovenous fistula | Inselspital, Bern University Hospital

  https://neurochirurgie.insel.ch/en/diseases-specialities/cerebral-vessels/dural-arteriovenous-fistula

  Dural arteriovenous fistulas (dAVFs) are acquired vascular malformations in which there is a pathological connection between arterial vessels of the meninges and venous vessels of the brain or spinal cord. […] Through the pathological connection of arteries and veins, the blood flows into the venous system at high arterial pressure. This leads to venous congestion and edema in the surrounding tissue, which can cause neurological deficits but also epileptic seizures. […] Dural arteriovenous fistulas with cortical venous drainage (Borden type II and III) have a significantly higher risk of rupture, and in addition, increased morbidity due to neurological deficits. […] The classification according to Borden (type IIII) mainly takes into account the venous drainage and thus also the risk of hemorrhage and the dangerous nature of the fistula.

• #1 Cerebral Dural Arteriovenous Fistulas—an Update on Pathophysiology, Natural History and Treatment | [current-page:pager]touchNEUROLOGY

  https://touchneurology.com/surgery/journal-articles/cerebral-dural-arteriovenous-fistulas-an-update-on-pathophysiology-natural-history-and-treatment/

  Dural arteriovenous fistulas are unique vascular shunts that can be discovered incidentally or after presentation with pulsatile tinnitus, ocular symptoms, focal neurologic deficits, and even hemorrhage. Their natural history is predicated on the shunts venous drainage pattern; presentation modality and venous ectasia are also independent factors influencing lesion natural history. […] The natural history of dAVFs should address the untreated course of associated symptomatology such as pulsatile tinnitus or ocular symptoms along with the risk of developing venous hypertension and/or hemorrhage. […] The presence or absence of drainage into leptomeningeal veins defines the modern dichotomy of high risk and low risk dAVFs, respectively. […] High risk dAVFs are more often diagnosed in men.

• #1 Updates in the management of cranial dural arteriovenous fistula | Stroke and Vascular Neurology

  https://svn.bmj.com/content/5/1/50

  Dural arteriovenous fistula (dAVF) accounts for approximately 10% of all intracranial vascular malformations. While they can be benign lesions, the presence of retrograde venous drainage and cortical venous reflux makes the natural course of these lesions aggressive high risk of haemorrhage, neurological injury and mortality. […] The aetiology of the dAVF is unclear in many instances; however, they are thought to be acquired after trauma, surgery, venous stenosis or sinus thrombosis. […] dAVFs with persistent CVR (Cognard type IIb-V or Borden types II and III) are aggressive and have been found to have an annual mortality of 10.4% with an annual haemorrhagic risk of 8.1% and an annual non-haemorrhagic neurological deficit risk of 6.9%. […] The location of the fistula and its subsequent disruption of normal venous drainage can cause changes in flow dynamics to produce symptoms.

• #1 Spinal Dural Arteriovenous Fistula: The Missing-Piece Sign | Ochsner Journal

  https://www.ochsnerjournal.org/content/22/1/10

  sDAVFs, although a rare pathology, are the most common vascular shunts of the spine, characterized by an abnormal communication between arteries and veins within the dura. These connections are classically located within the dura mater near spinal nerve roots. Branches of the radiculomeningeal artery make up the majority of the arterial components of the shunt, while the venous component usually consists of a radicular vein. Although their exact etiology is not fully understood, sDAVFs are presumed to be acquired lesions with several potential predisposing factors, including thrombosis of the extradural spinal veins and traumatic injury, although some lesions may be idiopathic. Communicating arteries cause decreased arteriovenous pressure gradients, leading to decreased venous drainage and subsequent venous congestion with intramedullary edema. This congestion can cause chronic hypoxia which, if left untreated, results in ischemia and necrosis.

• #1 Spinal Dural Arteriovenous Fistula: The Missing-Piece Sign | Ochsner Journal

  https://www.ochsnerjournal.org/content/22/1/10

  A characteristic enhancement pattern for sDAVFs known as the missing-piece sign has been recently described in the literature. The missing-piece sign can be seen on MRI and is defined as at least one discrete region of nonenhancement within a long segment of intense spinal cord gadolinium enhancement. In a case series, 86% of patients had intraparenchymal contrast enhancement, and the missing-piece sign was present in 43% of patients. This pattern of enhancement appears specific for the diagnosis of sDAVFs when compared to other patterns of spinal cord enhancement. […] A missing-piece sign pattern of enhancement, along with perimedullary vascular flow voids, should prompt additional evaluation with angiography. Angiography is a minimally invasive diagnostic procedure that uses fluoroscopy to visualize catheterized blood vessels with injection of contrast dye. Contrast stasis within radiculomedullary arteries, delayed venous return following injection, and retrograde contrast uptake within radiculomedullary veins are common findings indicating venous congestion and underlying shunting.

• #1 Intracranial dural arteriovenous fistula causing a myelopathy | Spinal Cord

  https://www.nature.com/articles/3101355

  The etiology of dural arteriovenous fistulas (in the brain or spinal cord) is usually not clear. They may arise spontaneously in older adults (40-60 years of age), often without antecedent history: but predisposing factors may include trauma some years earlier with symptoms developing later in life. Other factors could include prior surgery, or prior thrombophlebitis involving the venous sinuses (perhaps undiagnosed). Most often, no etiology is discovered. […] Symptoms at presentation may include: tinnitus, bruits, cranial nerve palsies, neurological deterioration, dementia and (if in the spinal cord), progressive paraplegia. […] If not treated, these fistulas worsen over time. There are rare cases of spontaneous cure. […] The pathophysiology proposed is venous hypertension with subsequent increase in congestion of the coronal plexus that drains the cord parenchyma. The increased pressure within the parenchyma produces ischemia by decreasing arteriole perfusion.

• #1 Dural Arteriovenous Fistula (dAVF): Symptoms & Treatment

  https://my.clevelandclinic.org/health/diseases/dural-arteriovenous-fistula-davf

  A dural arteriovenous fistula (dAVF) is an abnormal connection between an artery and vein within the protective cover around your brain and spinal cord (dura mater). […] A fistula develops when an artery connects directly to a vein without a capillary in between. As a result, the artery pumps lots of blood into a vein that isnt used to receiving so much blood flow. […] A dAVF can disrupt the pressure in your blood vessels, change the size and shape of the vessel, and prevent blood from traveling in the direction it needs to go. Sometimes, a vessel can break or burst due to the pressure. This can lead to life-threatening bleeding. […] Healthcare providers arent sure of the exact cause of dural arteriovenous fistulas. Most scientists think that they result from head trauma even if the traumatic event happened years ago. Some studies suggest it could relate to a blockage in the vessels that carry blood away from your brain.

• #1 Dural arteriovenous fistula (DAVF) | STROKE MANUAL

  https://www.stroke-manual.com/dural-arteriovenous-fistula-davf/

  Dural arteriovenous fistula (DAVF) is characterized by abnormal connections (shunts) between an artery and a vein; DAVF typically presents with tinnitus, hemorrhage, or venous hypertension. […] Most DAVFs are idiopathic; some patients have a history of previous craniotomy, head trauma, or dural sinus thrombosis. […] DAVFs usually have multiple feeders. […] Most typical drainage paths include transverse/sigmoid sinus, cavernous sinus, superior sagittal sinus, straight sinus, and cortical veins (associated with aggressive DAVFs and higher hemorrhage risk). […] This classification provides valuable data for the determination of the risk with each dural AV fistula and enables decision-making about the appropriate therapy. […] Type II and III have an annual risk of ~8%. […] Endovascular treatment involves occluding the abnormal connection between the artery and vein using embolization techniques.

• #1 Dural Arteriovenous Fistula (DAVF) – BWH Department of Neurosurgery

  https://www.brighamandwomens.org/neurosurgery/cerebrovascular/dural-arteriovenous-fistulae

  A dural arteriovenous fistula (DAVF) is an abnormal direct connection without any intervening capillaries between an artery and a vein. Some DAVFs result in high pressure in the brain and can result in brain hemorrhage. These DAVFs should be treated to prevent future bleeding in the brain. […] DAVFs can occur around the brain or the spinal cord. […] DAVFs can be treated by microsurgical obliteration, embolization (destroys a DAVF by selectively blocking blood supply), or radiosurgery. The best treatment of each DAVF is determined by a multidisciplinary team of neurosurgeons, endovascular surgeons, and radiation specialists at Brigham and Womens Hospital.

• #1 Dural Arteriovenous Fistula Causes, Symptoms, and Treatments

  https://www.upmc.com/services/neurosurgery/brain/conditions/neurovascular-conditions/conditions/dural-arteriovenous-fistula

  Dural arteriovenous fistulas (dAVFs) are rare, abnormal connections between arteries and veins in the dura, the protective lining of your brain. Having a dAVF can increase your risk of life-threatening complications, including brain hemorrhage, which can lead to a stroke. […] A dAVF may occur spontaneously or as a result of: Blood clot in a venous sinus, which drains blood from your brain. Head trauma. Infection. Surgery. […] dAVF is a life-threatening condition. Your prognosis after dAVF will depend on the severity of your condition, whether it causes symptoms, and how quickly you receive medical care. […] The goals of dAVF treatment are to reduce your risk of stroke and other complications. Treatment for dAVF depends on: The severity of your symptoms, if any. Your overall condition. Whether you have low- or high-risk dAVF.

• #1 Dural arteriovenous fistula masquerading as pulsatile tinnitus: radiologic assessment and clinical implications | Scientific Reports

  https://www.nature.com/articles/srep36601

  Pulsatile tinnitus (PT) is often an initial presenting symptom of dural arteriovenous fistula (dAVF), but it may be overlooked or diagnosed late if not suspected on initial diagnostic work-up. […] Of known underlying diseases, intracranial dural arteriovenous fistula (dAVF) is one of the most common causes of arterial pulse synchronous PT. […] dAVF indicates an abnormal direct connection between dural arteries and dural veins or a venous sinus, accounting for 10-15% of intracranial arteriovenous malformations. […] PT is often the sole initial symptom of dAVF, but a high index of suspicion and an appropriate evaluation are essential to avoid misdiagnosis and potentially catastrophic consequences. […] dAVFs have been managed with conservative treatment, neurosurgical resection, venous clipping, endovascular embolization, radiation therapy, and combinations of these methods.

• #1 Delayed Diagnosis of Spinal Dural Arteriovenous Fistula: A Case Report and Scoping Review

  https://www.mdpi.com/2077-0383/13/3/711

  Spinal dural arteriovenous fistula (SDAVF) is among the most common spinal arteriovenous shunt diseases, including SDAVF, intramedullary arteriovenous malformation (AVM), peripheral arteriovenous fistula (AVF), and perimedullary AVF. It is typically found in middle-age or older males’ thoracic spines. The disease manifests as a fistula between the radiculomeningeal artery and the radiculomedullary vein in the dura mater, near the spinal nerve root. This causes high-pressure blood flow from the artery to affect the veins around the spinal cord, causing their expansion and subsequent venous congestion and promoting myelopathy that leads to neurologic symptoms, such as numbness in the lower extremities, gait disturbance, and urinary retention. […] The primary reason for delayed and incorrect SDAVF diagnosis is that SDAVF is easily misrepresented as other diseases. Spinal degenerative diseases and myelitis are particularly common misdiagnoses.

• #1 Multiple Dural Arteriovenous Fistulas Manifesting as Progressive Otalg | CIA

  https://www.dovepress.com/multiple-dural-arteriovenous-fistulas-manifesting-as-progressive-otalg-peer-reviewed-fulltext-article-CIA

  Multiple cranial dural arteriovenous fistulas (dAVFs) are considered to be an uncommon vascular condition. […] The current hypothesis conjectures that the pathogenesis of dVAF is based on their association with venous outflow obstruction, ie, the resultant increase in venous pressure causes enlargement of the physiologic shunts between the dural arteries and sinuses that promote angioneogenesis through regional venous ischemia. […] Although the etiology of multiple dAVFs is unknown, the occurrence of cyclical sinus thrombotic occlusion and recanalization is one of the theories postulated to explain their pathogenesis. […] These fistulas may emerge after angioneogenesis as micro-shunts within the dura; several risk factors are known to increase the incidence of such fistulas, including venous sinus thrombosis, head trauma, transcranial surgery, transsinus procedures, hyper-coagulable states, and oral contraceptive use.

• #1

  https://journals.lww.com/neurosurgery/fulltext/2024/04000/dural_arteriovenous_fistulas_with_or_without.15.aspx

  Dural arteriovenous fistulas (DAVFs) are pathological anastomoses between dural arteries and venous sinuses or cortical veins, accounting for approximately 10%15% of all intracranial vascular malformations. The pathogenesis of DAVF is still controversial, which was initially believed to be congenital, but now generally considered to be acquired. Cerebral venous thrombosis (CVT) refers to the formation of thrombus in intracranial veins or venous sinuses because of various causes, which obstructs venous drainage and cerebrospinal fluid circulation, leading to intracranial hypertension and focal brain damage. It is a special subtype of cerebral vascular disease and accounts for approximately 0.5%1% of all strokes. The association of the two disease entities seems to be bidirectional. On the one hand, thrombus in the cerebral veins or venous sinuses can block blood flow, increase venous pressure and decrease cerebral perfusion, and cause the opening up of pre-existing physiological arteriovenous shunts or the stimulation of neoangiogenesis, ultimately leading to the formation of DAVF; on the other hand, DAVF may generate secondary CVT, as well. First, DAVF leads to turbulent flow into the venous sinus, which damages the intima and generates luminal thrombosis. Second, DAVF causes venous hypertension and blood stasis, leading to venous thrombosis.

• #1

  https://journals.lww.com/neurosurgery/fulltext/2024/04000/dural_arteriovenous_fistulas_with_or_without.15.aspx

  In our hospital-based cohort of 511 consecutive adult patients with DAVF, the prevalence of CVT was approximately one fifth (19.8%). We found that after adjusting for confounding factors, blurred vision, venous cerebral infarction, and LS-DAVF and MDAVF were the risk factors for the coexistence of CVT in patients with DAVF. […] Most importantly, on analyzing the relationship between the DAVF location and the CVT presence in patients with DAVF, we found that compared with other DAVF, LS-DAVF and MDAVF were more prone to combine with CVT, with a 4.801-fold and 5.640-fold increased risk, respectively. […] This patient cohort showed that the prevalence of CVT in Chinese adult DAVF was 19.8% and blurred vision, venous cerebral infarction, and LS-DAVF and MDAVF might be the risk factors for the coexistence of CVT in patients with DAVF.

• #1 Dural arteriovenous fistula presenting as thalamic dementia: a case description with rare imaging findings – Liu – Quantitative Imaging in Medicine and Surgery

  https://qims.amegroups.org/article/view/89723/html

  Dural arteriovenous fistula (dAVF) refers to an abnormal direct blood connection between an intracranial artery and a dural venous sinus. This fistula accounts for about 10% to 15% of all intracranial vascular malformations. […] Studies have shown that dAVF-induced retrograde venous hypertension can cause chronic passive hyperemia or venous ischemia, resulting in thalamic dementia and bilateral thalamic lesions. […] To date, the exact etiology and pathogenesis of thalamic dementia caused by dAVF have not been fully clarified. It has been hypothesized that venous hypertension caused by venous sinus thrombosis (VST) is a key causative factor in the formation of dAVF. The mechanisms involved in dAVF resulting from VST are complex. […] Research has shown that venous congestion and ischemia of the thalamus lead to venous hypertension and ultimately result in thalamic dementia.

• #1 Dural arteriovenous fistula presenting as thalamic dementia: a case description with rare imaging findings – Liu – Quantitative Imaging in Medicine and Surgery

  https://qims.amegroups.org/article/view/89723/html

  The thalamus is the subcortical center and transfer station of sensory conduction, but it also has an influence on the activities of the limbic and ascending reticular systems, and the cerebral cortex. Thalamic dementia refers to neurodegenerative diseases that manifest as dementia, including thalamic lesions, neuronal loss, and astrocytic hyperplasia, the symptoms of which include memory decline and cognitive dysfunction. […] In conclusion, thalamic dementia is a peculiar but reversible manifestation of dAVF, and its pathogenesis may be associated with venous hypertension.

• #1 Progress in research on intracranial multiple dural arteriovenous fistulas (Review)

  https://www.spandidos-publications.com/10.3892/br.2017.1021

  The exact pathogenesis underlying the development of single intracranial MDAVFs remains unknown. It has been suggested that MDAVFs share the same pathogenesis as single DAVFs, and that venous sinus thrombosis, congenital development, head trauma and surgical procedures may therefore be involved in the development of MDAVFs. […] In addition, conditions including infections, postpartum status and coagulopathies may provide a conducive environment for MDAVFs. […] However, in MDAVFs, multiple regions are simultaneously involved, and thus the mechanisms likely differ from those underlying the development of single DAVFs. […] Of all potential causes, venous hypertension following venous sinus thrombosis has been proposed to be a critical pathogenic factor. […] The mechanisms involved in venous sinus thrombosis leading to MDAVFs are complex. Inflammation may serve an important role by upregulating the release of angiogenic growth factors to cause neovascularization of the affected sinus wall.

• #2 Dural arteriovenous fistulas – Symptoms and causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/dural-arteriovenous-fistulas/symptoms-causes/syc-20364280

  Dural arteriovenous fistulas (dAVFs) are irregular connections between arteries and veins. They occur in the tough covering over the brain or spinal cord, known as the dura mater. The irregular passageways between arteries and veins are called arteriovenous fistulas, which can lead to bleeding in the brain or other serious symptoms. […] Although some dAVFs stem from known causes, most often the cause is not known. It’s thought that dAVFs involving large brain veins form when one of the brain’s venous sinuses narrows or becomes blocked. Venous sinuses are channels that route circulated blood from the brain back to the heart. […] Most dural arteriovenous fistulas (dAVFs) have no clear origin. But some result from a traumatic head injury, infection, previous brain surgery, blood clots in deep veins or tumors. […] Most experts think that dAVFs involving larger brain veins occur from the narrowing or blockage of one of the brain’s venous sinuses. The venous sinuses are channels in the brain that route circulated blood from the brain back to the heart.

• #2 Dural arteriovenous fistulas and headache features: an observational study | The Journal of Headache and Pain | Full Text

  https://thejournalofheadacheandpain.biomedcentral.com/articles/10.1186/s10194-020-1073-1

  Dural arteriovenous fistulas are intracranial vascular malformations, fed by dural arteries and draining venous sinuses or meningeal veins. […] The DAVFs etiology remains largely uncertain. Regardless of the causes, DAVFs are considered acquired rather than congenital lesions, assuming that the intracranial venous sinus hypertension leads to the development of fistulous connections between the arterial and the venous side of the dural wall. […] The clinical course of DAVFs varies widely and ranges from benign with spontaneous remission to fatal due to cerebral hemorrhage. […] Furthermore, the correlation between the venous drainage pattern, evaluated by conventional angiography, and the various clinical signs and symptoms defines diagnosis and classification of DAVFs. […] Symptoms depend on DAVF location and the pattern of the venous drainage. In particular, CCFs often present with ocular symptoms, due to the reversal of flow in the ophthalmic veins related to sinus increased pressure.

• #2 Investigation of the mechanism of dural arteriovenous fistula formation induced by high intracranial venous pressure in a rabbit model | BMC Neuroscience | Full Text

  https://bmcneurosci.biomedcentral.com/articles/10.1186/1471-2202-15-101

  The causes of dural arteriovenous fistula have not been clearly defined. The aim of this study was to investigate the mechanism of dural arteriovenous fistula formation induced by high intracranial venous pressure using a rabbit model. […] The results of the experiments in our rabbit model indicate that high intracranial venous pressure is a key for dural arteriovenous fistula formation. Cerebral ischemia caused by lack of cerebral perfusion pressure plays a key role in the process that leads from high intracranial venous pressure to increased hypoxia inducible factor-1 expression and then increased vascular endothelial growth factor expression. […] High venous pressure may result from venous sinus thrombosis or congenital thrombosis. There are various opinions about how high venous sinus pressure induces DAVF and many studies have been carried out that have focused on this issue.

• #2 Progress in research on intracranial multiple dural arteriovenous fistulas (Review)

  https://www.spandidos-publications.com/10.3892/br.2017.1021

  The exact pathogenesis underlying the development of single intracranial MDAVFs remains unknown. It has been suggested that MDAVFs share the same pathogenesis as single DAVFs, and that venous sinus thrombosis, congenital development, head trauma and surgical procedures may therefore be involved in the development of MDAVFs. […] In addition, conditions including infections, postpartum status and coagulopathies may provide a conducive environment for MDAVFs. […] However, in MDAVFs, multiple regions are simultaneously involved, and thus the mechanisms likely differ from those underlying the development of single DAVFs. […] Of all potential causes, venous hypertension following venous sinus thrombosis has been proposed to be a critical pathogenic factor. […] The mechanisms involved in venous sinus thrombosis leading to MDAVFs are complex. Inflammation may serve an important role by upregulating the release of angiogenic growth factors to cause neovascularization of the affected sinus wall.

• #2 Mechanism of the formation of dural arteriovenous fistula: the role of the emissary vein. – Abstract – Europe PMCEurope PMC

  https://europepmc.org/article/med/21696658

  Dural arteriovenous fistula (DAVF) can be separated into two types: DAVF which drains through an affected sinus (sinus type) and DAVF with direct reflux to the cortical vein (non-sinus type). The present report attempted to clarify the mechanism of formation and development of DAVF focusing on the emissary vein (EV) hypothesis. First, inflammation occurs at the penetrating point of the EV on the dura due to idiopathic or secondary causes. Local inflammatory reactions induce vessel dilatation and neovascularization, and subsequently create arteriovenous (AV) connections on the arteriole level. Although EV communicating with dural arteries might play a role as draining routes at first, they start to degrade due to compression of enlarged emissary arteries or to a hemodynamic shift to the drainage pathway of least resistance. Following the occlusion of drainage pathway through EV into the sinus or cortical veins may form, resulting in clinically detectable DAVF. The AV shunt then expands to the surrounding dura associated with recruitment of feeders from distant sites induced by expression of angiogenetic factors and a shift in the hemodynamic balance. In sinus type DAVF, the sinus is progressively compartmentalized and finally occludes due to thrombogenesis with activated coagulopathy or to hemodynamic hypertrophy of the sinus wall. This progression results in the mature, aggressive DAVF with drainage impairments. Previous mechanistic hypotheses focusing on sinus hypertension and sinus thromboses cannot explain the pathogenesis of non-sinus type of DAVF. Although the etiology of DAVF may be concerned by the thrombo-occlusive change of sinus, the unique theory presented in this report may enable an understanding of the common etiology of both types of DAVF.

• #2 Dural arteriovenous fistula | Radiology Reference Article | Radiopaedia.org

  https://radiopaedia.org/articles/dural-arteriovenous-fistula?lang=us

  Dural arteriovenous fistulas (dAVF) are a heterogeneous collection of conditions that share arteriovenous shunts from dural vessels. They present variably with hemorrhage or venous hypertension and can be challenging to treat. […] Dural arteriovenous fistulas are usually acquired and in most instances are idiopathic. In patients with a documented antecedent cause, most occur as a result of neovascularization induced by a previously thrombosed dural venous sinus (typically the transverse sinus). Other causes include trauma and previous craniotomy. It is likely that at least some patients with apparently idiopathic fistulae had prior asymptomatic thrombosis, particularly as inherited prothrombotic conditions (e.g. antithrombin, protein C, and protein S deficiencies) have been associated with the development of dural arteriovenous fistulas.

• #2 Dural Arteriovenous Fistula – Neuropedia

  https://neuropedia.net/articles/neurosurgery/vascular/dural-arteriovenous-fistula/

  Dural arteriovenous fistulas (dAVFs), in some cases, called Dural arteriovenous malformation (AVMs), are anomalous and abnormal connections between the arterial and venous systems within the protective dural layer of the brain. The exact cause of dAVFs is usually not known, but they are believed to develop as a result of factors like trauma, surgical interventions, venous narrowing, or blood clot formation in the brains venous sinuses. […] Even though we dont fully understand the underlying mechanisms of these lesions, it appears that Dural Arteriovenous Fistulas (dAVFs) in adults are primarily acquired conditions. They involve multiple blood vessels originating from specific areas of the meninges and are supplied by arteries such as the external/internal carotid and vertebral arteries. Previous factors such as craniotomy, injuries, blood clot formation, and underlying thrombotic disorders like protein C/S deficiency and Factor V Leiden have been suggested as potential contributing factors.

• #2 Investigation of the mechanism of dural arteriovenous fistula formation induced by high intracranial venous pressure in a rabbit model | BMC Neuroscience | Full Text

  https://bmcneurosci.biomedcentral.com/articles/10.1186/1471-2202-15-101

  The vascular remodeling (expression of endothelial growth factor and angiogenesis) due to vascular lesion-induced high venous pressure and hypoxia or hemodynamic changes has been proposed to be the key factor for new DAVF formation. […] We believe that high intracranial pressure is the key factor in DAVF formation. There are direct physiological arteriovenous pathways in the dural vascular structures. These physiological pathways are open when there is a high venous pressure, which results in fistula formation. However, the blood flow in these fistulae is limited and cannot form a DAVF immediately; further vascular remodeling is required. […] The detailed processes are illustrated in Figure 9.

• #2 Progress in research on intracranial multiple dural arteriovenous fistulas (Review)

  https://www.spandidos-publications.com/10.3892/br.2017.1021

  In addition to MDAVFs caused by acquired factors, certain intracranial MDAVFs may be congenital in origin, particularly those observed in children. […] In summary, the exact pathogenesis underlying the development of intracranial MDAVFs remains unclear, though venous sinus thrombosis, angiogenic factors, disturbed hemodynamics and congenital factors are considered to be potential causes.

• #2 Review of spinal dural arteriovenous fistulas: Challenges, diagnostics, management, and pathophysiology

  https://www.probiologists.com/article/review-of-spinal-dural-arteriovenous-fistulas-challenges-diagnostics-management-and-pathophysiology

  Another possible pathway is that KRIT1 and PDCD10 both affect Notch signaling. […] Thus, when PDCD10 is downregulated, this leads to the upregulation of BMP6 and ERK1/2 transcriptional activity. […] The ultimate result is hyper angiogenesis, once again. […] Furthermore, to study protein changes in sdAVFs, one study looked at histology and pathologic changes under sustained high vascular pressure (abbreviated as sdAVF-DV or sdAVF-draining vein). […] Overall conclusions include smooth muscle cell dysfunction and inflammation. […] When looking at the formation of sdAVFs, inner vessel wall inflammation might lead to insufficient extracellular matrix and trigger changes in pathological proteins. […] However, no specific predictive biomarkers have been identified thus far. […] Current screening strategies for sdAVFs rely on MRI imaging with or without enhancement. […] In conclusion, while several molecular mechanisms and possible biomarker targets have been suggested, further study is needed to elucidate pathways in sdAVF formation and possible biomarkers.

• #2 Journal of Cerebrovascular and Endovascular Neurosurgery

  https://the-jcen.org/m/journal/view.php?number=809

  While the exact mechanisms are still controversial, venous sinus thrombosis and venous hypertension have been believed to be associated with the genesis of DAVFs. […] Two etiologic hypotheses regarding to sinus thrombosis and venous hypertension have been suggested. […] Once triggered by venous hypertension and venous thrombosis, arterial feeder recruitment and development of DAVFs via neoangiogenesis might proceed.

• #2 Spinal Dural Arteriovenous Fistulas | American Journal of Neuroradiology

  http://www.ajnr.org/content/30/4/639

  This transition is classically located directly underneath the pedicle of the vertebral body, which is supplied by the injected segmental artery. […] The increase in spinal venous pressure due to arterialization diminishes the AV pressure gradient and leads to a decreased drainage of normal spinal veins and a venous congestion with intramedullary edema because the intramedullary veins and the radicular vein share a common venous outflow. […] This congestion, in turn, leads to chronic hypoxia and progressive myelopathy. […] Direct intraoperative measurement of the vascular pressure of the fistula was found to be as high as 74% of the systemic arterial pressure. […] This finding may explain why, in some patients, symptoms become worse during physical activity with a concomitant increase in arterial pressure. […] Because the lower thoracic region has relatively fewer venous outflow channels compared with the cervical region, the venous congestive edema is likely to be transmitted in a caudocranial direction throughout the spinal cord.

• #2 :: KJR :: Korean Journal of Radiology

  https://www.kjronline.org/DOIx.php?id=10.3348/kjr.2015.16.5.1119

  Chronic venous hypertension and stagnation decrease tissue perfusion and lead to edema of the spinal cord and progressive myelopathy. […] The perimedullary venous plexus receives blood from radial veins draining the intramedullary circulation from the spinal cord dorsally in 80-90% of cases. […] Cervical SDAVF is rare, and presents with hemorrhage more often than thoracolumbar counterparts, possibly due to a higher blood flow rate. […] Tadi et al. demonstrated a narrowing of the intervertebral veins at the point crossing the dura mater. […] It was hypothesized that the zigzag fashion and the narrowing of the intervertebral vein prevent blood flow going backwards to the intradural space, only permitting blood flow in a physiological direction. […] However, patients with SDAVF may be asymptomatic despite the damaged „anti-flow back system” due to alternate venous outflow into ascending perimedullary veins, which open to the external paravertebral venous plexus via the upper cervical region. […] Spontaneous angiographic conversion of progressive thrombosis and venous outflow obstruction related to aging has been reported in intracranial dural arteriovenous fistulae.

• #2 Dural arteriovenous fistula | Inselspital, Bern University Hospital

  https://neurochirurgie.insel.ch/en/diseases-specialities/cerebral-vessels/dural-arteriovenous-fistula

  This type of dAVF has a high risk of rupture and subsequent neurological problems. Therefore, the goal of treatment here is to repair the abnormal connection between the artery and the vein. […] Spinal dural arteriovenous fistulas usually cause venous blood stasis in the spinal cord, which can lead to slowly progressive damage to the spinal cord with symptoms ranging from gait disturbance and weakness in the legs to paraplegia.

• #2 Cerebral Dural Arteriovenous Fistulas—an Update on Pathophysiology, Natural History and Treatment | [current-page:pager]touchNEUROLOGY

  https://touchneurology.com/surgery/journal-articles/cerebral-dural-arteriovenous-fistulas-an-update-on-pathophysiology-natural-history-and-treatment/

  These fistulas pose a risk of symptomatic venous hypertension resulting in nonhemorrhagic neurological deficits (NHND) or frank intracranial hemorrhage. […] Venous ectasia has also been found to be an independent risk factor for a more aggressive course. […] Overall clinical and angiographic results for embolization are excellent for well selected fistulas. […] High risk fistulas whose shunt sites cannot be occluded by endovascular means can be treated by identifying the draining leptomeningeal vein exiting the dura and disconnecting it surgically. […] Low risk fistulas with tolerable symptoms or those that cannot be occluded endovascularly may be treated with radiosurgery.

• #2 Dural Arteriovenous Fistulas | Baylor Medicine

  https://www.bcm.edu/healthcare/specialties/neurosurgery/cerebrovascular-and-stroke-surgery/dural-arteriovenous-fistulas

  Dural arteriovenous fistulas (DAVFs) are abnormal connections between arteries and veins within the covering of the brain (dura). […] DAVFs lead to increased pressure in brain veins which can result in a variety of symptoms. […] Certain patients can develop bleeding into the brain. Patients at risk are those who have a DAVF that drains abnormal, high-pressure artery blood flow directly into veins of the brain. This is a dangerous situation known as cortical venous drainage (CVD). […] Treatment options for brain AVFs include: Endovascular Embolization – This procedure entails passing a small catheter from a blood vessel in the groin up into the AVF, where glue or other material is injected into the abnormal vessel. This is the most common treatment of DAVF and is often curative.

• #2 Spinal dural arteriovenous fistulas: Pathogenesis, clinical manifestations, diagnosis, treatment | Evzikov | Neurology, Neuropsychiatry, Psychosomatics

  https://nnp.ima-press.net/nnp/article/view/523?locale=en_US

  The paper describes spinal dural arteriovenous fistulas (SDAVF), the most common type of spinal cord vascular anomalies. SDAVFs account for 6080% of the spinal cord vascular anomalies. The causes of SDAVFs, the specific features of their hemodynamics, and their classification remain the subject matter of disputes. […] SDAVFs form in dura mater tissue, on the dorsal surface of radicular cuffs. The pathogenesis of neurological disorders in SDAVF has determined the name venous hypertensive myelopathy, a spinal cord injury occurring in their presence. Pain and paresthesias, cacesthesia (more commonly in their distal parts), and motor disorders as flail legs are observed at the onset of SDAVF in typical cases. On average, 12 to 44 months elapse to establish its diagnosis. In addition of motor and sensory disorders, sphincter impairments and sexual dysfunction are detected in the patients at the time of diagnosis. By this time, most patients have already neurological disability. […] The paper presents the history of studying SDAVF, the existing classifications of arteriovenous malformations and fistulas, the clinical manifestations of venous hypertensive myelopathy in SDAVF, neuroimaging findings, and treatment options.

• #2 :: KJR :: Korean Journal of Radiology

  https://www.kjronline.org/DOIx.php?id=10.3348/kjr.2015.16.5.1119

  Spinal dural arteriovenous fistula (SDAVF) is the most common spinal vascular malformation, however it is still rare and underdiagnosed. […] The exact etiology of SDAVF remains unclear. The majority of patients become symptomatic in middle age, suggesting that it is an acquired disease. Male predilection is also well known. […] Typically, one (sometimes multiple) feeding artery from a radiculopial artery or a dural branch of a radiculopial artery enters an intervertebral or radicular vein and forms a SDAVF within the dorsal surface of the dural root sleeve in the intervertebral foramen. […] The feeding artery 'arterializes’ the intervertebral vein, destroys the arteriovenous gradient and increases venous pressure, resulting in wall thickening and tortuosity of radial veins (also known as intramedullary veins), since intervertebral and radial veins share a common venous outflow.

• #2 Spinal Dural Arteriovenous Fistula: The Missing-Piece Sign | Ochsner Journal

  https://www.ochsnerjournal.org/content/22/1/10

  A characteristic enhancement pattern for sDAVFs known as the missing-piece sign has been recently described in the literature. The missing-piece sign can be seen on MRI and is defined as at least one discrete region of nonenhancement within a long segment of intense spinal cord gadolinium enhancement. In a case series, 86% of patients had intraparenchymal contrast enhancement, and the missing-piece sign was present in 43% of patients. This pattern of enhancement appears specific for the diagnosis of sDAVFs when compared to other patterns of spinal cord enhancement. […] A missing-piece sign pattern of enhancement, along with perimedullary vascular flow voids, should prompt additional evaluation with angiography. Angiography is a minimally invasive diagnostic procedure that uses fluoroscopy to visualize catheterized blood vessels with injection of contrast dye. Contrast stasis within radiculomedullary arteries, delayed venous return following injection, and retrograde contrast uptake within radiculomedullary veins are common findings indicating venous congestion and underlying shunting.

• #2 Intracranial dural arteriovenous fistula causing a myelopathy | Spinal Cord

  https://www.nature.com/articles/3101355

  The myelopathy is produced as a result of increased blood flow from the high-pressure arterial system through the fistula into the lower pressure venous system. Due to the valve-less nature of the spinal venous plexus, backward flow can occur, producing venous congestion with resultant hemorrhage or ischemia. […] In this particular case, the vascular anomaly was located at a distance away from the cord in an intracranial location. There were multiple feeder vessels involved with the fistula, and the venous outflow involved vessels that were not directly associated with the spinal cord venous drainage. However, through a complex series of anastomotic venous channels the anterior spinal vein does connect to the petrosal vein. The resultant increase in venous hypertension ultimately reaches the cord parenchyma via the valve-less anastomotic channels and produces a myelopathy similar to the typical dural AV fistula. […] Early identification and treatment is important as intervention in either case can often prevent further neurological decline or reverse the myelopathic changes.

• #2 Dural Arteriovenous Fistula (dAVF): Symptoms & Treatment

  https://my.clevelandclinic.org/health/diseases/dural-arteriovenous-fistula-davf

  Complications of dAVF can be life-threatening and may include: Bleeding within your brain tissue (hemorrhage). […] Treatment can remove the fistula and improve blood flow in your blood vessels as expected. It can reduce and prevent new symptoms and complications from happening. […] The goal of dural arteriovenous fistula treatment is to remove the abnormal connection (fistula) between your artery and vein. Treatment options could include: Surgery: Open surgery can remove the fistula (abnormal connection) of the affected blood vessel. […] Your prognosis depends on many factors, like the location of the fistula and whether bleeding has occurred. With early discovery and treatment, your prognosis is positive. Unfortunately, some dural arteriovenous fistulas can lead to permanent or life-threatening complications. […] A dural arteriovenous fistula (dAVF) is a condition that can have a major or limited impact on your life. Some cases dont cause disruptions and only need close monitoring by your healthcare provider. Others can cause permanent or life-threatening complications if not diagnosed and treated quickly.

• #2 Dural arteriovenous fistula (DAVF) | STROKE MANUAL

  https://www.stroke-manual.com/dural-arteriovenous-fistula-davf/

  Endovascular treatment is typically considered for DAVFs with a higher risk of bleeding, such as Borden II and III or Cognard IIb-V DAVFs. […] Stereotactic radiosurgery (SRS) is a minimally invasive second-line treatment option if endovascular or surgical treatment is not feasible or has been unsuccessful.

• #2 Updates in the management of cranial dural arteriovenous fistula | Stroke and Vascular Neurology

  https://svn.bmj.com/content/5/1/50

  Endovascular approach is the first-line treatment for most dAVFs. The mainstay for endovascular treatment involves embolisation of the fistulous connection and its venous components while preventing adverse effects. […] Inappropriate embolisation of the fistulous connection and venous portions could cause sudden changes in the flow dynamics and potentially worsen cortical venous flow. […] Cyanoacrylate adhesives are widely used for the embolisation of dAVFs with high flow. […] Onyx can be the preferred treatment option based on the type and location of the cerebral dAVF. […] Endovascular treatment with Onyx has shown to achieve a higher rate of dAVF cure than n-BCA. […] Stereotactic radiosurgery (SRS) is usually reserved as a last salvage option for treatment of dAVF. Endothelial cell damage and thrombosis are suggested as the main mechanisms of dAVF occlusion by radiation. […] While endovascular techniques are often considered first-line therapy for treatment of dAVFs, surgery remains an alternate effective and safe option.

• #2 Dural Arteriovenous Fistula Causes, Symptoms, and Treatments

  https://www.upmc.com/services/neurosurgery/brain/conditions/neurovascular-conditions/conditions/dural-arteriovenous-fistula

  Endovascular embolization is a minimally invasive treatment. During embolization, your doctor will insert a thin, flexible tube called a catheter into an incision in your groin. Using x-ray imaging guidance, your doctor will guide the catheter to the dAVF. Your doctor will then use glue, coils or, most commonly, Onyx (an occlusive substance) to close off the fistula. […] Gamma Knife radiosurgery is a safe, noninvasive treatment that uses highly focused radiation beams to precisely target and close the dAVF reducing the risk of damage to nearby brain tissue. […] If you are not a candidate for an endovascular embolization or radiosurgery procedure, your doctor may recommend a procedure called craniotomy to treat your dAVF. It involves removing a piece of your skull to access your brain and disconnecting the dAVF.

• #2 Dural arteriovenous fistula masquerading as pulsatile tinnitus: radiologic assessment and clinical implications | Scientific Reports

  https://www.nature.com/articles/srep36601

  Considering that most dAVFs are curable with presently available treatment modalities, accurate diagnosis of dAVF presenting with only PT by performing a meticulous physical examination and choosing appropriate neuroimaging modalities is essential. […] To sum up, PT was the only initial symptom in more than 10% of dAVF, and the transverse-sigmoid sinus was the most common site of dAVF triggering PT. […] PT improved in 92.3% of cases after endovascular embolization, and there were no significant differences in the cure rate according to anatomical location or drainage pattern. […] If PT is the only presenting symptom in patients with dAVF, prompt management by endovascular embolization can prevent further neurological and neurosurgical complications. […] In most cases, PT originating from dAVF can be cured by transarterial embolization regardless of the location and venous drainage pattern.

• #2 Delayed Diagnosis of Spinal Dural Arteriovenous Fistula: A Case Report and Scoping Review

  https://www.mdpi.com/2077-0383/13/3/711

  A typical patient with SDAVF has symptoms similar to thoracic myelopathy, epiconus syndrome, and conus medullaris syndrome. Thoracic myelopathy produces motor weakness in the proximal lower extremities, posterior funiculus dysfunction, and amplified deep-tendon reflexes. Epiconus syndrome is characterized by progressive numbness, developing upward from the distal lower extremities. In conus medullaris syndrome, bowel and bladder dysfunction and claudication can occur while walking, bathing, drinking, sleeping, gardening, and even singing. […] MRI can detect the venous congestion of the spinal cord characteristic of SDAVF with up to 100% sensitivity. Most patients with SDAVFs present high peripheral signal intensity on T2-weighted MRI. […] The treatment goal is to prevent the flow of blood from the proximal intradural vein and fistula. If treatment is delayed, lower-limb weakness, paresthesia, and bladder–rectal dysfunction can persist. Early diagnosis and treatment are therefore essential; results emphasize their importance in SDAVF.

• #2 Multiple Dural Arteriovenous Fistulas Manifesting as Progressive Otalg | CIA

  https://www.dovepress.com/multiple-dural-arteriovenous-fistulas-manifesting-as-progressive-otalg-peer-reviewed-fulltext-article-CIA

  The etiology of pain in dAVF is attributed to the direct communication between the dural arteries and venous sinuses or meningeal venous lacunae, with antegrade venous drainage that increases flow through the dural sinuses or venous channels; dAVFs commonly produce benign symptoms such as headaches, otalgia due to pulsatile tinnitus, and painful ophthalmoplegia due to accumulated venous drainage toward the cavernous sinus that can sometimes result in painful proptosis. […] An extensive understanding of the complex vascular architecture of dAVFs is required and can facilitate the selection of the optimal treatment strategy, as performed in the posterior condylar dural fistula described in this case. […] Transarterial ONYX embolization should be the first option for dAVFs located at any site, except cavernous DAVFs. […] The Onyx embolic material is recommended for TAE of dAVFs because it is superior to glue or coils, with respect to safety and facilitates a high rate of complete obliteration.

• #2

  https://journals.lww.com/neurosurgery/fulltext/2024/04000/dural_arteriovenous_fistulas_with_or_without.15.aspx

  In our hospital-based cohort of 511 consecutive adult patients with DAVF, the prevalence of CVT was approximately one fifth (19.8%). We found that after adjusting for confounding factors, blurred vision, venous cerebral infarction, and LS-DAVF and MDAVF were the risk factors for the coexistence of CVT in patients with DAVF. […] Most importantly, on analyzing the relationship between the DAVF location and the CVT presence in patients with DAVF, we found that compared with other DAVF, LS-DAVF and MDAVF were more prone to combine with CVT, with a 4.801-fold and 5.640-fold increased risk, respectively. […] This patient cohort showed that the prevalence of CVT in Chinese adult DAVF was 19.8% and blurred vision, venous cerebral infarction, and LS-DAVF and MDAVF might be the risk factors for the coexistence of CVT in patients with DAVF.

• #2

  https://journals.lww.com/neurosurgery/fulltext/2024/04000/dural_arteriovenous_fistulas_with_or_without.15.aspx

  Dural arteriovenous fistulas (DAVFs) are pathological anastomoses between dural arteries and venous sinuses or cortical veins, accounting for approximately 10%15% of all intracranial vascular malformations. The pathogenesis of DAVF is still controversial, which was initially believed to be congenital, but now generally considered to be acquired. Cerebral venous thrombosis (CVT) refers to the formation of thrombus in intracranial veins or venous sinuses because of various causes, which obstructs venous drainage and cerebrospinal fluid circulation, leading to intracranial hypertension and focal brain damage. It is a special subtype of cerebral vascular disease and accounts for approximately 0.5%1% of all strokes. The association of the two disease entities seems to be bidirectional. On the one hand, thrombus in the cerebral veins or venous sinuses can block blood flow, increase venous pressure and decrease cerebral perfusion, and cause the opening up of pre-existing physiological arteriovenous shunts or the stimulation of neoangiogenesis, ultimately leading to the formation of DAVF; on the other hand, DAVF may generate secondary CVT, as well. First, DAVF leads to turbulent flow into the venous sinus, which damages the intima and generates luminal thrombosis. Second, DAVF causes venous hypertension and blood stasis, leading to venous thrombosis.

• #2 Dural arteriovenous fistula presenting as thalamic dementia: a case description with rare imaging findings – Liu – Quantitative Imaging in Medicine and Surgery

  https://qims.amegroups.org/article/view/89723/html

  The thalamus is the subcortical center and transfer station of sensory conduction, but it also has an influence on the activities of the limbic and ascending reticular systems, and the cerebral cortex. Thalamic dementia refers to neurodegenerative diseases that manifest as dementia, including thalamic lesions, neuronal loss, and astrocytic hyperplasia, the symptoms of which include memory decline and cognitive dysfunction. […] In conclusion, thalamic dementia is a peculiar but reversible manifestation of dAVF, and its pathogenesis may be associated with venous hypertension.

• #3 Journal of Cerebrovascular and Endovascular Neurosurgery

  https://the-jcen.org/m/journal/view.php?number=809

  Dural arteriovenous fistulas (DAVFs) are pathologic shunts between pachymeningeal arteries and dural venous channel. […] The etiology and pathophysiology of DAVFs is not fully understood. […] The pathophysiology of development of lesions and neurological deterioration is different in patients with DAVF and those with intradural spinal AVMs. […] Although complex pathophysiologic mechanisms underlying the development of spinal DAVFs are yet to be clarified, meningeal venous thrombosis and trauma are implicated in the development of spinal DAVFs. […] Histopathological examination supported the theory of venous hypertension as a pathophysiological mechanism in the development of DAVFs and increased venous congestion as a cause of neurological deterioration. […] An increased venous pressure results in a reduced arteriovenous pressure gradient, intramedullary impairment of autoregulation, and hypoxia.

• #3 Pathophysiology and classification of intracranial and spinal dural AVF

  http://the-jcen.org/journal/view.php?doi=10.7461/jcen.2022.E2021.04.001

  Dural arteriovenous fistulas (DAVFs) are pathologic shunts between pachymeningeal arteries and dural venous channel. […] The etiology and pathophysiology of DAVFs is not fully understood. […] Several hypotheses for development of DAVF and classifications for predicting risk of hemorrhage and neurological deficit have been proposed to help clinical decision making according to its natural history. […] The etiology of DAVFs is not fully understood, but the majority of DAVFs in adulthood appear to be acquired. […] Different etiologies have been implicated such as trauma, previous craniotomy, and a hypercoagulable state including malignancy, pregnancy, infection, and prothrombotic genes. […] A meningeal branch of each artery supplying the brain or spinal cord consistently pierce the dura through a venous sinus or else are surrounded by a venous plexus.

• #3 Investigation of the mechanism of dural arteriovenous fistula formation induced by high intracranial venous pressure in a rabbit model | BMC Neuroscience | Full Text

  https://bmcneurosci.biomedcentral.com/articles/10.1186/1471-2202-15-101

  The vascular remodeling (expression of endothelial growth factor and angiogenesis) due to vascular lesion-induced high venous pressure and hypoxia or hemodynamic changes has been proposed to be the key factor for new DAVF formation. […] We believe that high intracranial pressure is the key factor in DAVF formation. There are direct physiological arteriovenous pathways in the dural vascular structures. These physiological pathways are open when there is a high venous pressure, which results in fistula formation. However, the blood flow in these fistulae is limited and cannot form a DAVF immediately; further vascular remodeling is required. […] The detailed processes are illustrated in Figure 9.

• #3 Progress in research on intracranial multiple dural arteriovenous fistulas (Review)

  https://www.spandidos-publications.com/10.3892/br.2017.1021

  Numerous angiogenic factors, including platelet-derived endothelial-cell growth factor, fibroblast growth factor and transforming growth factor- may also provide a conducive environment for the development of intracranial single DAVFs. […] When the first intracranial DAVF develops, the hemodynamics of the venous system in the brain is disturbed, and this may induce the development of new DAVFs, eventually resulting in the formation of metachronous-type MDAVFs. […] It has been hypothesized that the following two mechanisms are involved in this process: i) Venous drainage caused by an established DAVF may cause turbulent flow or stagnation in the distant venous sinus, resulting in thrombosis of the sinus and development of additional DAVFs; ii) venous hypertension may cause the development of a DAVF, and the elevation in sinus pressure caused by the initial DAVF may result in the formation of multiple new DAVFs at other sites.

• #3 Dural Arteriovenous Fistula – Neuropedia

  https://neuropedia.net/articles/neurosurgery/vascular/dural-arteriovenous-fistula/

  It is believed that the development of dAVFs may be linked to the gradual narrowing of the dural venous sinuses; clot formation in the dural venous sinuses which could trigger the formation of new blood vessels (neoangiogenesis) as part of the diseases pathogenesis; and previously thrombosed dural venous sinus. […] The primary anomaly seen in dural arteriovenous fistulas (dAVFs) is the formation of connections between dural arteries and veins within the walls of venous sinuses, typically through small vessels averaging around 30 micrometers in diameter. In cases where there is an identifiable triggering event, the development of new blood vessels (neovascularization) is often initiated by a previously thrombosed dural venous sinus, with the transverse sinus being a common site. […] For patients with idiopathic fistulas, the condition is usually associated with prior asymptomatic blood clot formation within a dural venous sinus. This clot formation is often a result of inherited conditions that increase the risk of blood clot formation, such as anti-thrombin, protein C deficiency, and protein S deficiency, or due to systemic illnesses and conditions that promote a Pro-thrombotic state.

• #3 Spinal Dural Arteriovenous Fistulas | American Journal of Neuroradiology

  http://www.ajnr.org/content/30/4/639

  This transition is classically located directly underneath the pedicle of the vertebral body, which is supplied by the injected segmental artery. […] The increase in spinal venous pressure due to arterialization diminishes the AV pressure gradient and leads to a decreased drainage of normal spinal veins and a venous congestion with intramedullary edema because the intramedullary veins and the radicular vein share a common venous outflow. […] This congestion, in turn, leads to chronic hypoxia and progressive myelopathy. […] Direct intraoperative measurement of the vascular pressure of the fistula was found to be as high as 74% of the systemic arterial pressure. […] This finding may explain why, in some patients, symptoms become worse during physical activity with a concomitant increase in arterial pressure. […] Because the lower thoracic region has relatively fewer venous outflow channels compared with the cervical region, the venous congestive edema is likely to be transmitted in a caudocranial direction throughout the spinal cord.

• #3 Delayed Diagnosis of Spinal Dural Arteriovenous Fistula: A Case Report and Scoping Review

  https://www.mdpi.com/2077-0383/13/3/711

  Spinal dural arteriovenous fistula (SDAVF) is among the most common spinal arteriovenous shunt diseases, including SDAVF, intramedullary arteriovenous malformation (AVM), peripheral arteriovenous fistula (AVF), and perimedullary AVF. It is typically found in middle-age or older males’ thoracic spines. The disease manifests as a fistula between the radiculomeningeal artery and the radiculomedullary vein in the dura mater, near the spinal nerve root. This causes high-pressure blood flow from the artery to affect the veins around the spinal cord, causing their expansion and subsequent venous congestion and promoting myelopathy that leads to neurologic symptoms, such as numbness in the lower extremities, gait disturbance, and urinary retention. […] The primary reason for delayed and incorrect SDAVF diagnosis is that SDAVF is easily misrepresented as other diseases. Spinal degenerative diseases and myelitis are particularly common misdiagnoses.

• #3

  https://journals.lww.com/md-journal/fulltext/2024/10110/dural_arteriovenous_fistula_may_be_occluded.29.aspx

  To investigate the effect and safety of recanalization of stenosed or occluded venous sinuses for dural arteriovenous fistulas (DAVFs) and possible mechanism of DAVF formation, patients with DAVF accompanied by venous sinus stenosis or occlusion treated with balloon angioplasty and/or stenting were retrospectively enrolled. […] The true etiology of DAVFs is unclear although the common mechanism is thought to be venous hypertension, which may be caused by obstruction of the venous outflow because of venous or sinus thrombosis, stenosis, or occlusion or because of increased blood hypercoagulation states or viscosity. […] Moreover, relief of the venous hypertension via balloon angioplasty and stent deployment in the involved sinuses has been shown to be able to resolve the DAVFs. […] Endovascular recanalization of the involved sinuses in DAVFs using balloon angioplasty and stent deployment may thus be considered a better alternative therapy because endovascular recanalization of the involved sinuses is able to eliminate the venous hypertension caused by sinus stenosis, occlusion, or increased blood hypercoagulation states or viscosity.

• #3

  https://journals.lww.com/neurosurgery/fulltext/2024/04000/dural_arteriovenous_fistulas_with_or_without.15.aspx

  In our hospital-based cohort of 511 consecutive adult patients with DAVF, the prevalence of CVT was approximately one fifth (19.8%). We found that after adjusting for confounding factors, blurred vision, venous cerebral infarction, and LS-DAVF and MDAVF were the risk factors for the coexistence of CVT in patients with DAVF. […] Most importantly, on analyzing the relationship between the DAVF location and the CVT presence in patients with DAVF, we found that compared with other DAVF, LS-DAVF and MDAVF were more prone to combine with CVT, with a 4.801-fold and 5.640-fold increased risk, respectively. […] This patient cohort showed that the prevalence of CVT in Chinese adult DAVF was 19.8% and blurred vision, venous cerebral infarction, and LS-DAVF and MDAVF might be the risk factors for the coexistence of CVT in patients with DAVF.

• #4 Pathophysiology and classification of intracranial and spinal dural AVF

  http://the-jcen.org/journal/view.php?doi=10.7461/jcen.2022.E2021.04.001

  Dural arteriovenous fistulas (DAVFs) are pathologic shunts between pachymeningeal arteries and dural venous channel. […] The etiology and pathophysiology of DAVFs is not fully understood. […] Several hypotheses for development of DAVF and classifications for predicting risk of hemorrhage and neurological deficit have been proposed to help clinical decision making according to its natural history. […] The etiology of DAVFs is not fully understood, but the majority of DAVFs in adulthood appear to be acquired. […] Different etiologies have been implicated such as trauma, previous craniotomy, and a hypercoagulable state including malignancy, pregnancy, infection, and prothrombotic genes. […] A meningeal branch of each artery supplying the brain or spinal cord consistently pierce the dura through a venous sinus or else are surrounded by a venous plexus.

• #4 Spinal dural arteriovenous fistula | Radiology Reference Article | Radiopaedia.org

  https://radiopaedia.org/articles/spinal-dural-arteriovenous-fistula?lang=us

  Spinal dural arteriovenous fistulas (SDAVF) are the most common type of spinal vascular malformation, accounting for ~70% of all such lesions. […] These fistulae are abnormal direct connections between a radicular/radiculomeningeal artery and a radicular/pial vein in the dura of an adjacent nerve root sleeve. 85% of SDAVFs consist of a single transdural arterial feeder, however, there are cases with many arterial feeders originating from either a single or multiple levels that may be either unilateral or bilateral. […] The direct arterial inflow into the venous system raises the pressure within the coronal venous plexus, which is valveless. The coronal venous plexus dilates and venous drainage of the cord decreases, causing venous congestion and intramedullary edema (congestive or venous hypertensive myelopathy). Cord ischemia and infarction may result. Nearly 60% of SDAVFs are spontaneous, with the remainder being caused by trauma.

• #4 Delayed Diagnosis of Spinal Dural Arteriovenous Fistula: A Case Report and Scoping Review

  https://www.mdpi.com/2077-0383/13/3/711

  A typical patient with SDAVF has symptoms similar to thoracic myelopathy, epiconus syndrome, and conus medullaris syndrome. Thoracic myelopathy produces motor weakness in the proximal lower extremities, posterior funiculus dysfunction, and amplified deep-tendon reflexes. Epiconus syndrome is characterized by progressive numbness, developing upward from the distal lower extremities. In conus medullaris syndrome, bowel and bladder dysfunction and claudication can occur while walking, bathing, drinking, sleeping, gardening, and even singing. […] MRI can detect the venous congestion of the spinal cord characteristic of SDAVF with up to 100% sensitivity. Most patients with SDAVFs present high peripheral signal intensity on T2-weighted MRI. […] The treatment goal is to prevent the flow of blood from the proximal intradural vein and fistula. If treatment is delayed, lower-limb weakness, paresthesia, and bladder–rectal dysfunction can persist. Early diagnosis and treatment are therefore essential; results emphasize their importance in SDAVF.

• #4

  https://journals.lww.com/md-journal/fulltext/2024/10110/dural_arteriovenous_fistula_may_be_occluded.29.aspx

  Our study investigated the effect and safety of endovascular recanalization of occluded venous sinuses for the treatment of DAVF. It was found that endovascular recanalization of the involved occluded or stenotic venous sinuses was safe and efficient in inducing occlusion or relief of the DAVFs which were probably caused by significant pressure increase. […] Studies have found that the essential abnormality of DAVFs is not a newly created direct arteriovenous shunt to the sinus lumen but innative connections of small venules of approximately 30 m in diameter between the dural arteries and dural veins within the venous sinus wall. […] These studies believed that sinus hypertension triggered development of fistulous connections between arteries and veins inside the dural wall, which is an essential part of the pathogenesis of DAVFs.

• #4 Progress in research on intracranial multiple dural arteriovenous fistulas (Review)

  https://www.spandidos-publications.com/10.3892/br.2017.1021

  In addition to MDAVFs caused by acquired factors, certain intracranial MDAVFs may be congenital in origin, particularly those observed in children. […] In summary, the exact pathogenesis underlying the development of intracranial MDAVFs remains unclear, though venous sinus thrombosis, angiogenic factors, disturbed hemodynamics and congenital factors are considered to be potential causes.

• #5 Pathophysiology and classification of intracranial and spinal dural AVF

  http://the-jcen.org/journal/view.php?doi=10.7461/jcen.2022.E2021.04.001

  This intimate relationship between the meningeal branches and the venous sinuses offers anatomical opportunity for the development of fistulas. […] While the exact mechanisms are still controversial, venous sinus thrombosis and venous hypertension have been believed to be associated with the genesis of DAVFs. […] Two etiologic hypotheses regarding to sinus thrombosis and venous hypertension have been suggested. […] Angiogenic growth factors, produced as a result of sinus thrombosis, might contribute to the development of DAVFs. […] Whether the cause or the result of hemodynamic disturbance, venous hypertension and thrombophilic condition such as venous thrombosis clearly plays a role in the development of DAVFs. […] Once triggered by venous hypertension and venous thrombosis, arterial feeder recruitment and development of DAVFs via neoangiogenesis might proceed.

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