What Is CVST?
Cerebral Venous Sinus Thrombosis (CVST) is a type of rare blood clot that forms in the venous sinuses in your brain. This is a system of veins found between the layers of the dura mater -- the tough outer layer of your brain that lies directly under your skull.
The clot can block the blood in your brain from draining out toward your heart. When this happens, blood cells may break from the pressure, cross the blood-brain barrier, and seep into nearby brain tissue. This can cause a hemorrhage, a type of stroke that stems from internal bleeding. CVST can be life-threatening. You’ll need immediate medical attention.
CVST affects about 5,000 people in the U.S. each year. It makes up about 0.5% of all strokes and can affect both adults and children. It can even happen to newborns or babies while they’re still in the womb. The risk for new mothers is especially high during the first few weeks after delivery.
What Causes It?
A number of things can cause the clot to form in your brain. Risk factors differ for adults and children or newborns. It’s more common in women than men.
For children, the risk factors include:
- Sickle cell anemia
- Chronic hemolytic anemia -- when your body destroys red blood cells faster than it creates new ones
- Beta-thalassemia major -- a disorder where you lack red blood cells that carry oxygen
- Heart disease -- you can either be born with it or develop it
- Lack of iron
- Certain types of infections that affect your ear, face, or neck
- Head injury
- Blood clotting problems
CVST is more likely in newborns if the mother has had certain infections. A history of infertility can also increase the risk.
For adults, the risk factors include:
- High levels of post-pregnancy estrogen
- Medications with estrogen like birth control pills, patch, or ring
- Problems forming blood clots
- Collagen vascular diseases like lupus, Wegener’s granulomatosis, and Behcet syndrome
- Low blood pressure in your brain
- Gut conditions like Crohn’s disease or ulcerative colitis
Sometimes, despite a lot of tests, your doctor may not find an obvious cause. In adults over 65, the chance of not finding a cause or risk factor is around 37%.
Symptoms of CVST
CVST symptoms vary depending on where the clot forms in your brain. It can cause stroke-like symptoms including:
- Blurred vision
- Loss of control over movement in part of the body
- Trouble speaking
- Numbness in legs, arms, or both
If you or a loved one have stroke-like symptoms, call 911 right away.
Diagnosis and Treatment
In the emergency room, the doctor may get a detailed medical history, do a physical exam, and ask questions about symptoms. They’ll do imaging tests like a brain MRI or CT scan to check for bleeding or signs of a clot in the brain. That’s the surest way to confirm and diagnose a stroke from a blood clot like CVST.
Other tests may include:
- Blood tests
The stroke and pressure from the blood clot may cause your brain to swell. Once you’re diagnosed with CVST, you’ll be admitted to the hospital. Treatment will begin right away. Depending on the severity of the stroke and symptoms, treatment type and length may vary.
Your treatment plan may include:
- Anti-seizure medications (if you’ve had one)
- Blood-thinning medications like heparin to stop blood clots from forming
- Surgery to remove the clot
- Antibiotics if you’ve had an infection
- Monitoring your brain to prevent pressure from building up
- Checking your eyesight for possible changes
After you’ve been stable for a few days, the doctor may start you on a blood thinning medication called warfarin that you take by mouth. It prevents your body from forming more clots. Depending on what caused the clot, the doctor may have you take it for 3-12 months or longer if you need it.
Can You Prevent CVST?
There are things you can do to lower your chances of getting a CVST or making an emergency trip to the hospital. For one, build heart-healthy habits into your daily routine. You can:
If you’re not sure how to get started, ask your doctor what lifestyle options will work best for you. If you’re taking prescription medications, ask the doctor if any of them could boost your risk for a blood clot.
If you’ve had a clot, it’s important that immediate family members like siblings, children, or parents know they now have a higher chance of developing one too. If your clot is genetic -- a type you get from your parents at birth -- they may have to get tested for it. They can talk to a doctor about CVST and other types of blood clots, possible symptoms, and what to do in case of an emergency.
What's the Outlook?
About 80% affected by a CVST recover fully. But depending on the severity of your stroke, it may take weeks or even months to get back to normal. You may have ongoing symptoms like headaches or seizures. You’ll need routine health checks with your doctor to monitor your progress.
Possible complications from a CVST stroke include:
- Speech problems
- Trouble moving body parts
- Vision problems
- Nerve pressure problems
- Developmental delays in children or newborns
- Brain injury
- In severe cases, death
As part of your recovery plan, you may need rehabilitation or physical therapy to regain movement and control. For speech and vision problems, you may have to consult specialists. They can help build a treatment plan to address those issues.
After you’ve had CVST, you may be at a higher risk to form other types of clots like deep vein thrombosis and pulmonary embolisms that form in your legs and travel to the lung. Ask your doctor what you can do to prevent another stroke or clot in the future.