Cerebral Venous Sinus Thrombosis

What is cerebral venous sinus thrombosis (CVST)?

Cerebral venous sinus thrombosis (CVST) is a blood clot in one of your brain’s larger veins. This rare issue makes up 1% of types of stroke.

When a blood clot blocks a major vein in your brain, your blood flows the wrong way. This increases the pressure in your brain and causes it to swell.

Typical locations for blood clots from CVST include your:

• Transverse sinus.
• Superior sagittal sinus.
• Inferior sagittal sinus.
• Sigmoid sinuses.
• Cavernous sinus.
• Deep sinuses of your cortex.

Who does cerebral venous sinus thrombosis affect?

Cerebral venous sinus thrombosis happens more often in people assigned female at birth (AFAB). Although most people get it in their 40s and 50s, you can get it at a younger age — even in infancy.

You’re more likely to get cerebral venous sinus thrombosis if you already have:

• Nephrotic syndrome.
• Cancer.
• Vasculitis.
• Sarcoidosis.
• Obesity.
• COVID-19.
• Thrombophilia.
• Liver disease.

How common is cerebral venous sinus thrombosis?

Cerebral venous sinus thrombosis is rare. Researchers estimate anywhere from 2 to 15 cases per 1 million people per year. An estimated 7 children and babies per 1 million get cerebral venous sinus thrombosis each year.

How does cerebral venous sinus thrombosis affect my body?

CVST complications may include:

• Loss of vision.
• Hemorrhage (loss of blood from a broken blood vessel).
• Headache.
• Seizure.
• Stroke.

What are the symptoms?

Cerebral venous sinus thrombosis symptoms depend on how bad the clot is and its location.

Symptoms include:

• Headache that keeps getting worse (most common symptom).
• Seizures.
• Altered mental status and/or new neurologic deficits in the case of a large brain bleed.

What causes cerebral venous sinus thrombosis?

Cerebral venous sinus thrombosis causes include:

• Being pregnant.
• Taking oral contraceptives (birth control pills).
• Experiencing a trauma.
• Having an inherited condition (thrombophilia) that makes your blood clot easily.
• Having an infection (for example, a COVID-19 infection).

A very small number of people had CVST after receiving a COVID-19 vaccine.

How is cerebral venous sinus thrombosis diagnosed?

Your healthcare provider will use brain imaging to diagnose cerebral venous sinus thrombosis. A prompt diagnosis gives you the best chance of avoiding complications.

What tests will be done to diagnose cerebral venous sinus thrombosis?

To diagnose cerebral venous sinus thrombosis, your healthcare provider can use imaging, such as:

• Brain MRI (magnetic resonance imaging) with contrast (dye).
• Brain CT (computed tomography) with contrast.
• Magnetic resonance venography (MRV), CT venography or cerebral angiography.

They might also do blood tests, like a hypercoagulability panel, to look for a clotting disorder.

How is cerebral venous sinus thrombosis treated?

Treatment of cerebral venous sinus thrombosis includes:

• Anticoagulants, such as heparin, even during pregnancy.
• Thrombolytics (“clot-busting drugs”).
• Antibiotics if an infection caused your thrombosis.
• Removal of the clot (thrombectomy) with surgery for severe cases.
• Acetazolamide or medical procedures to lower your intracranial pressure (pressure in your brain).
• Antiepileptic medicines for seizures.

You may need to take warfarin (Coumadin® or Jantoven®) or a direct oral anticoagulant (such as rivaroxaban, apixaban or dabigatran) for three to 12 months, depending on what caused your cerebral venous sinus thrombosis. People with thrombophilia may need to take warfarin for the rest of their lives.

Complications/side effects of the treatment

If you’re taking warfarin, it’s important to be sure you’re taking the right dose. That’s why your healthcare provider will do frequent tests of your blood’s ability to clot. Your dose needs to be high enough to prevent clots that could harm you, but not so high of a dose that you can’t stop bleeding if you get a cut.

How soon after treatment will I feel better?

When you get the anticoagulant heparin through an IV or injection, it works very quickly. As it can take about a week for warfarin to work, your healthcare provider will keep you on heparin until the warfarin starts working. Then, you can stop receiving heparin and just take warfarin by itself.

Alternatively, if your healthcare provider chooses a direct oral anticoagulant, it can thin your blood at the desired level within a few hours. Depending on how soon the clot starts to resolve and the intracranial pressure buildup improves, you may start feeling better.

How can I reduce my risk?

If you had a CVST while you were pregnant, an anticoagulant may lower your risk of thrombosis for future pregnancies.

Oral contraceptives are one cause of cerebral venous sinus thrombosis. Not using oral contraceptives can help reduce your risk of this condition. You can use contraceptives that contain only progestin instead.

Smoking, combined with oral contraceptive use, increases the risk of CVST, too. Avoiding both of these can help prevent CVST.

What can I expect if I have cerebral venous sinus thrombosis?

In the past, 50% of people with cerebral venous sinus thrombosis survived. Now, the condition has a fatality percentage of fewer than 5% to 10% of people who have it. This is because of better imaging and treatments.

A cerebral venous sinus thrombosis can happen again, which is why your healthcare provider will prescribe anticoagulants.

How long cerebral venous sinus thrombosis lasts

Cerebral venous sinus thrombosis can last hours or weeks. Your case will be in one of these categories:

• Acute: Up to 48 hours.
• Subacute: More than 48 hours, but up to 30 days. (This is the most common type.)
• Chronic: One month or longer.

Outlook for cerebral venous sinus thrombosis

The outlook is good for people who get the right diagnosis and treatment for cerebral venous sinus thrombosis. However, CVST can be fatal if you aren’t diagnosed and treated early.

How do I take care of myself?

After you’ve had a cerebral venous sinus thrombosis, your healthcare provider will want to keep you from having another blood clot. This means you’ll need to take an anticoagulant or “blood thinner” like warfarin.

This can protect you from a dangerous clot, but can put you at risk of bleeding from everyday cuts, as well. You’ll want to be careful when using knives and consider switching to an electric razor, which may be safer than a razor with a blade.

When should I see my healthcare provider?

You’ll need to see your healthcare provider regularly (perhaps every few months) while you’re taking anticoagulants. Contact your healthcare provider if you miss a dose of warfarin.

You may need to have another CT or MRI with contrast three to six months after you have a cerebral venous sinus thrombosis to follow up on the status of your cerebral venous blood clot.

When should I go to the ER?

Call 911 if you’re taking warfarin and have signs of bleeding, such as:

• Bleeding that you can’t stop.
• Severe headache.
• Bright red blood when you cough, throw up (vomit) or poop.

What questions should I ask my doctor?

• What caused my cerebral venous sinus thrombosis?
• How long do I need treatment?
• How high is my risk of cerebral venous sinus thrombosis happening again?

A note from Cleveland Clinic

A cerebral venous sinus thrombosis, or CVST, can happen again, so it’s important to go to all of your follow-up appointments with your healthcare provider. They’ll want to make sure you’re taking the right dose of medicine to prevent another CVST. If you’re taking a blood thinner, it’s also important to avoid activities that carry a risk of injury. Even everyday tasks involving knives or scissors have the potential for a cut that makes you bleed. Adopting safer options, like an electric razor, will become a safer habit.