Cavernous sinus thrombosis, or CST, occurs when a blood clot develops in the cavernous sinuses, located below the brain, behind each eye. Running through the cavernous sinuses is a major blood vessel, the jugular vein, which carries blood from the brain to the heart and lungs. A blood clot in this vein can cause increasing pressure in the vein. Most cases of cavernous sinus thrombosis are caused by a bacterial infection; the immune system creates a blood clot to prevent the infection from spreading. CST is a rare but life-threatening condition, requiring antibiotics and often a 3-4 week hospital stay. Without treatment, cavernous sinus thrombosis is often fatal. If you experience the symptoms listed below, contact your doctor immediately.
The most common symptoms of CST include severe eye pain and swelling or bulging of the eyes. The eyes are usually the first to be affected, because of their proximity to the cavernous sinuses. Other eye-related symptoms include redness, the sensation of your eyes being heavy or full, vision problems such as double vision or vision loss, and difficulty controlling eye movement or moving the eye in a particular direction. Eye symptoms may occur in one or both eyes; often, the symptoms begin in one eye and spread to the other within 24-48 hours.
Many people with cavernous sinus thrombosis also experience a persistent, sharp headache, particularly behind or around the eyes. While it is highly unlikely that a headache alone indicates CST, it is a symptom that requires further investigation, as it could be a sign of any number of serious medical conditions.
If left untreated, the infection can spread, causing a high fever, seizures, changes in mental state such as confusion, speech problems, and weakness on one or both sides of the body. As the condition progresses, the pressure caused by cavernous sinus thrombosis can cause irreversible brain damage. If antibiotics are not delivered, most people with cavernous sinus thrombosis will become increasingly drowsy, before falling into a coma. Untreated cavernous sinus thrombosis can be fatal. People who have recovered from CST may experience long-term health issues such as persistent headaches and seizures.