Cerebral venous sinus thrombosis (CVST) – spot the signs

Cerebral venous thrombosis is a blood clot of a vein in the brain. The clot causes blood to first collect in the vein before leaking into the brain tissues. 

What are the symptoms?

When to get urgent medical help 

What’s the cause and who can be affected? 

How is CVST diagnosed and treated?

What’s the outlook?

CVST is when a blood clot develops in one of your brain’s larger veins, usually as the result of a bacterial infection. The condition is rare but can be life-threatening. Here’s how to spot the signs and get the help you need.

Cerebral venous sinus thrombosis (CVST) happens when a blood clot develops in one of the larger veins in the brain, which are called the cerebral venous sinuses. There are several venous sinuses in the brain, including the cavernous sinuses.  

Blood is transported through your venous sinuses away from your brain and into your jugular veins, but if you have an infection, a blood clot can develop to stop it from flowing freely. This causes a type of stroke that can cause damage to your brain, nerves, and eyes. Clots can also appear without an infection. 

This rare condition may also be referred to as cerebral venous thrombosis. Sometimes it may be called [cavernous sinus thrombosis](https://www.livehealthily.com/health-library/conditions/cavernous-sinus-thrombosis), although this condition refers to a clot that develops in veins in the cavernous sinuses (hollow spaces found under the brain, behind each eye socket).


## What are the symptoms?

If you have cerebral venous sinus thrombosis (CVST), one of the first symptoms may include a very painful headache, often around your eye area.

You may also:
- have eye pain, or notice swollen or bulging eyes
- blurred or double vision
- eyelid dropping or problems moving your eyes

Other symptoms may happen if the condition is not treated and spreads through your body, including:
- fever (high temperature)
- seizures (fits)
- feeling nauseous or vomiting
- being confused 
- muscle weakness that affects different parts of your body
- feeling drowsy, which can eventually lead to a coma.


Get help with this

## When to get urgent medical help 

If you have symptoms of CVST seek urgent medical care. In particular, check for: 

- a bad headache that does not get any better after taking pain relief, or gets worse
- a headache that gets worse when lying down or bending over
- a type of headache you don’t usually get, along with blurred vision, nausea or vomiting, feeling weak or drowsy, or having speech problems or seizures (fits) 
- pain or swelling in 1 or both eyes
- a rash that looks like bleeding under the skin or bruising 
- chest pain, swelling in the leg, constant belly pain, or feeling short of breath. 


## What’s the cause and who can be affected? 
Cerebral venous sinus thrombosis (CVST) is usually caused by a bacterial infection spreading from your face or skull, and a blood clot developing as a result. This might be due to [sinusitis](https://www.livehealthily.com/health-library/conditions/sinusitis) or a [boil](https://www.livehealthily.com/health-library/conditions/boils). But it’s important to point out that these infections are common and it is rare they would lead to CVST.

It’s less common, but a blood clot can also happen in the cerebral venous sinuses, because of:
- an injury to your head
- a fungal infection
- a tooth or gum infection that spreads ([dental abscess](https://www.livehealthily.com/health-library/conditions/dental-abscess))
- a condition that makes you more prone to [blood clots](https://www.livehealthily.com/health-library/conditions/thrombosis), such as being pregnant
- conditions that cause inflammation in the body, such as [lupus](https://www.livehealthily.com/health-library/conditions/lupus)
- taking oral contraceptives, although this is rare
- being female, possibly due to factors like pregnancy and taking the pill, which can be risk factors
- having [coronavirus (COVID-19)](https://www.livehealthily.com/health-library/conditions/coronavirus-covid19)
- a side-effect of some types of [COVID-19 vaccine](https://www.livehealthily.com/self-care/what-to-expect-after-having-the-covid-19-vaccine), in very rare cases.


## How is CVST diagnosed and treated?

Cerebral venous sinus thrombosis (CVST) needs medical treatment in hospital.

You’ll be asked about your health history and have a physical examination. Diagnosis is usually made according to how blood is flowing in the brain. You’ll be likely to have tests including an MRI and CT scan, plus blood tests. 

Treatment can include:
- __antibiotics__ – to treat bacterial infection (this may be given as a precaution even if the cause of your clot is still unknown)
- __anticoagulants__ – to break down the blood clot you have and prevent future clots 
- __corticosteroids__ to reduce swelling in your brain 
- __medicine to control seizures__ if needed
- __surgical drainage__ – to get rid of pus caused by a boil or sinusitis, for example 
- __surgery to remove the blood clot (thrombectomy)__ if your case is severe.


## What’s the outlook?

It’s a serious condition – studies show cerebral venous sinus thrombosis (CVST) is fatal for approximately 3 to 15% of people. Survival rates have improved due to better imaging in tests and more effective treatment. 

To recover and keep healthy after CVST depends on how you were affected. You may need physical therapy or a rehabilitation plan if you lose any movement or speech. 

Long-term health problems can include headaches and vision loss, due to brain damage, and these will need further treatment.  

Take positive steps to benefit your health by following a healthy diet, taking regular exercise and avoiding smoking.


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References

Fiona Bugler

Jo Wheatley

Dr Ewan O'Farrell

Article information

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Cerebral venous sinus thrombosis (CVST) is when a rare blood clot develops in a vein in your brain. It can cause headaches and severe eye pain and prompt treatment is vital. Find out more.