Cerebral venous sinus thrombosis (CVST) refers to a thrombosis (blood clot) in the brain, of which there are several types: dural venous sinus thrombosis, cortical vein thrombosis and deep cerebral vein thrombosis. Each of these thrombosis types can appear very similar and be difficult to distinguish via imaging. They also often exist together.
Dural venous sinus thrombosis (DVST) can affect men and women of any age, but it is more likely to present in women who are pregnant or on birth control pills.
There are a lot of potential causes of dural venous sinus thrombosis, but the main risk factors include:
- Hormonal changes, such as those caused by the oral contraceptive pill, pregnancy, steroids, or hypothyroidism
- Abnormalities of the skull
- Skull trauma
- Infections of the mastoid sinus (behind the middle ear)
- Systemic illnesses, such as dehydration, sepsis or connective tissue disorders
- Iron deficiency anemia
- Folic acid deficiency
Symptoms of a DVST can range from asymptomatic (no symptoms at all) to coma or death. However, various symptoms in between may include:
- Decreased or altered consciousness
- Decreased or altered vision
- Nausea or vomiting
While DVST is a relatively rare condition, affecting only five people per million, it can lead to fatal consequences and is the cause of .5 to 1 percent of all strokes. Pregnant women are at greater risk because of their hypercoagulable (abnormality in blood clotting) state. Unfortunately, treating women in pregnancy can become even more complicated due to the need to weigh the risks to both mother and child.
Because of their increased risk factors, pregnant women and women on birth control pills may be monitored more closely for symptoms of DVST. Should DVST (or any other CVST) be suspected, imaging tests will typically be ordered. These might include:
- Computed tomography (CT)
- Magnetic resonance imaging (MRI)
- Cerebral angiography
A D-dimer blood test may also be ordered (to show if the blood clot is breaking up), with studies showing that 34 out of 35 patients with DVST will have abnormal D-dimer results. However, the D-dimer test seems to be most helpful in detecting cases of more developed thrombosis.
Left untreated, CVSTs present up to a 48 percent mortality rate. Studies have estimated that with treatment, patients have up to a 62.5 percent full recovery rate. Treatment options include:
- Anticoagulation Drugs: Heparin and Warfarin are used for systemic anticoagulation, in the hopes of breaking up or reducing the clot. This is often used even when thrombolysis (surgical destruction of the clot) is anticipated.
- Thrombolysis: This procedure is used to dissolve dangerous clots in your blood vessels, improve blood flow, and prevent organ and tissue damage. During the procedure, your interventional neuroradiologist injects clot-busting drugs through an intravenous (IV) line or a long catheter, delivering drugs directly to the site of the blockage. Your physician may also use a device attached to the end of the catheter to remove or break up the clot.