A cavernous sinus thrombosis is a rare and life-threatening condition in which a blood clot develops in a part of the skull called the cavernous sinuses (see below).
Symptoms of a cavernous sinus thrombosis include:
- a sharp and severe headache
- swelling of the eyes
- eye pain that is often severe
Read more about the symptoms of cavernous sinus thrombosis.
You should contact your GP straight away if you experience any of these symptoms.
The cavernous sinuses
The cavernous sinuses are a series of hollow spaces located under the bottom of the brain, behind each eye socket.
Running through the sinuses is a major blood vessel called the jugular vein whose role is to carry blood away from the brain and back to the heart and lungs.
When to see your GP
You should always contact your GP if you are experiencing a persistent and severe headache that you have not had before.
While it is highly unlikely to be the result of a cavernous sinus thrombosis, a persistent headache is a symptom that usually requires further investigation.
You should also contact your GP if you develop swelling of the eyes or severe eye pain.
Causes
Most cases of cavernous sinus thrombosis are caused when a bacterial infection (or much less commonly, a fungal infection) in another part of the skull spreads into the cavernous sinuses.
The immune system, which is the body’s defence against infection, will then create a blood clot inside the cavernous sinuses to prevent the infection from spreading.
The blood clot can then place the brain under increasing pressure, which can damage the brain and, without treatment, will inevitably prove fatal.
Read more about what causes cavernous sinus thrombosis.
Treatment
The main treatment for cavernous sinus thrombosis is antibiotics, which are normally provided through a drip that is directly connected to a vein in the arm.
Most people will need to stay in hospital for 3-4 weeks before they are well enough to leave.
Read more about the treatment of cavernous sinus thrombosis.
Who is affected by cavernous sinus thrombosis?
Cavernous sinus thrombosis is a very rare condition. One study estimated that only 1 in every 2.5 million people in England will develop cavernous sinus thrombosis in any given year.
The condition is three times more common in women than men. It is thought that the two main reasons for this are that pregnancy and taking the oral contraceptive pill can make women more vulnerable to blood clots.
Younger adults and children are more likely to be affected by a cavernous sinus thrombosis than older adults.
Outlook
Cavernous sinus thrombosis is an extremely serious condition and even with prompt treatment as many as one in three people with the condition will die from related complications.
Around one in ten people who do survive will develop long-term health problems as the result of damage to their brain, such as persistent headaches and fits. Read more about the complications of cavernous sinus thrombosis.
