| Developmental venous anomaly | |
|---|---|
| Other names | Venous angioma |
 | |
| Developmental venous anomaly in the cerebellum seen on axial contrast-enhanced T1 weighted MRI | |
A developmental venous anomaly (DVA, formerly known as venous angioma) is a congenital variant of the cerebral venous drainage. On imaging it is seen as a number of small deep parenchymal veins converging toward a larger collecting vein.
DVA can be characterized by the caput medusae sign of veins, which drains into a larger vein. The drains will either drain into a dural venous sinus or into a deep ependymal vein. It appears to look like a palm tree. [1]
Most common locations for the DVA: [1]
| Location | Percent of DVA | Notes |
|---|---|---|
| Frontoparietal morphoea | 36–64% | Drains towards the frontal horn of the lateral ventricles. |
| Cerebellar hemisphere | 14–27% | Drains into the fourth ventricle. |
DVA can be diagnosed through the cerebral venous sinus thrombosis with collateral drainage. DVA can also be found diagnosed with Sturge–Weber syndrome and can be found through leptomeningeal angiomatosis. Demyelinating disease has also been found to enlarge medulla veins. [2]
Veins are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal circulations which carry oxygenated blood to the heart. In the systemic circulation, arteries carry oxygenated blood away from the heart, and veins return deoxygenated blood to the heart, in the deep veins.
The great cerebral vein is one of the large blood vessels in the skull draining the cerebrum of the brain. It is also known as the vein of Galen, named for its discoverer, the Greek physician Galen.
Cerebral circulation is the movement of blood through a network of cerebral arteries and veins supplying the brain. The rate of cerebral blood flow in an adult human is typically 750 milliliters per minute, or about 15% of cardiac output. Arteries deliver oxygenated blood, glucose and other nutrients to the brain. Veins carry "used or spent" blood back to the heart, to remove carbon dioxide, lactic acid, and other metabolic products. The neurovascular unit regulates cerebral blood flow so that activated neurons can be supplied with energy in the right amount and at the right time. Because the brain would quickly suffer damage from any stoppage in blood supply, the cerebral circulatory system has safeguards including autoregulation of the blood vessels. The failure of these safeguards may result in a stroke. The volume of blood in circulation is called the cerebral blood flow. Sudden intense accelerations change the gravitational forces perceived by bodies and can severely impair cerebral circulation and normal functions to the point of becoming serious life-threatening conditions.
Intracranial hemorrhage (ICH), also known as intracranial bleed, is bleeding within the skull. Subtypes are intracerebral bleeds, subarachnoid bleeds, epidural bleeds, and subdural bleeds.
The emissary veins connect the extracranial venous system with the intracranial venous sinuses. They connect the veins outside the cranium to the venous sinuses inside the cranium. They drain from the scalp, through the skull, into the larger meningeal veins and dural venous sinuses.
The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica.
The dural venous sinuses are venous sinuses (channels) found between the endosteal and meningeal layers of dura mater in the brain. They receive blood from the cerebral veins, and cerebrospinal fluid (CSF) from the subarachnoid space via arachnoid granulations. They mainly empty into the internal jugular vein.
The confluence of sinuses, torcular Herophili, or torcula is the connecting point of the superior sagittal sinus, straight sinus, and occipital sinus. It is below the internal occipital protuberance of the skull. It drains venous blood from the brain into the transverse sinuses. It may be affected by arteriovenous fistulas, a thrombus, major trauma, or surgical damage, and may be imaged with many radiology techniques.
The superior sagittal sinus, within the human head, is an unpaired area along the attached margin of the falx cerebri. It allows blood to drain from the lateral aspects of anterior cerebral hemispheres to the confluence of sinuses. Cerebrospinal fluid drains through arachnoid granulations into the superior sagittal sinus and is returned to venous circulation.
A dural arteriovenous fistula (DAVF) or malformation is an abnormal direct connection (fistula) between a meningeal artery and a meningeal vein or dural venous sinus.
Cavernous sinus thrombosis (CST) is the formation of a blood clot within the cavernous sinus, a cavity at the base of the brain which drains deoxygenated blood from the brain back to the heart. This is a rare disorder and can be of two types–septic cavernous thrombosis and aseptic cavernous thrombosis. The most common form is septic cavernous sinus thrombosis. The cause is usually from a spreading infection in the nose, sinuses, ears, or teeth. Staphylococcus aureus and Streptococcus are often the associated bacteria.
The cerebellar veins are veins which drain the cerebellum. They consist of the superior cerebellar veins and the inferior cerebellar veins. The superior cerebellar veins drain to the straight sinus and the internal cerebral veins. The inferior cerebellar veins drain to the transverse sinus, the superior petrosal sinus, and the occipital sinus.
The smallest cardiac veins are small, valveless veins in the walls of all four heart chambers that drain venous blood from the myocardium directly into any of the heart chambers.
Cerebral venous sinus thrombosis (CVST), cerebral venous and sinus thrombosis or cerebral venous thrombosis (CVT), is the presence of a blood clot in the dural venous sinuses, the cerebral veins, or both. Symptoms may include severe headache, visual symptoms, any of the symptoms of stroke such as weakness of the face and limbs on one side of the body, and seizures, which occur in around 40% of patients.
A vascular malformation is a blood vessel or lymph vessel abnormality. Vascular malformations are one of the classifications of vascular anomalies, the other grouping is vascular tumors. They may cause aesthetic problems as they have a growth cycle, and can continue to grow throughout life.
Anomalous pulmonary venous connection is a congenital defect of the pulmonary veins.
Sinus pericranii (SP) is a rare disorder characterized by a congenital epicranial venous malformation of the scalp. Sinus pericranii is an abnormal communication between the intracranial and extracranial venous drainage pathways. Treatment of this condition has mainly been recommended for aesthetic reasons and prevention of bleeding.
Vein of Galen aneurysmal malformations(VGAMs) and Vein of Galen aneurysmal dilations (VGADs) are the most frequent arteriovenous malformations in infants and fetuses. A VGAM consists of a tangled mass of dilated vessels supplied by an enlarged artery. The malformation increases greatly in size with age, although the mechanism of the increase is unknown. Dilation of the great cerebral vein of Galen is a secondary result of the force of arterial blood either directly from an artery via an arteriovenous fistula or by way of a tributary vein that receives the blood directly from an artery. There is usually a venous anomaly downstream from the draining vein that, together with the high blood flow into the great cerebral vein of Galen causes its dilation. The right sided cardiac chambers and pulmonary arteries also develop mild to severe dilation.
The empty delta sign is a radiologic sign seen on brain imaging which is associated with cerebral venous sinus thrombosis. It is usually seen on magnetic resonance imaging (MRI) or computed tomography (CT) scans with contrast. It is seen as dural wall enhancement in the absence of intra-sinus enhancement. This is due to the presence of a blood clot in the dural venous sinuses. The dural venous sinuses drain blood from the brain to the internal jugular veins, which in turn drains blood to the heart. It has been proposed that the empty delta sign occurs in dural venous thromboses due to contrast material filling the dural venous collateral circulation immediately surrounding the dura whilst being unable to fill the intra-dural sinus space due to the presence of a blood clot. The superior saggital sinus is most commonly affected, but the radiologic sign may also be seen in the transverse sinuses.
Raghib syndrome is rare a congenital heart defect where the left superior vena cava (LSVC) is draining into the left atrium in addition to an absent coronary sinus and an atrial septal defect. This can be considered a dangerous heart condition because it puts the individual at a high risk of stroke. Other defects that are often associated with Raghib syndrome can include ventricular septal defects, enlargement of the tricuspid annulus, and pulmonary stenosis. While this is considered an extremely rare developmental complex, cases regarding a persistent left superior vena cava (PLSVC) are relatively common among congenital heart defects. It is also important to note that the PLSVC often drains into the right atrium, and only drains into the left atrium in approximately 10 to 20% of individuals with the defect.