Cavernous sinus thrombosis
Cavernous sinus thrombosis is a blood clot in an area at the base of the brain.
Blood clot
Blood clots are clumps that occur when blood hardens from a liquid to a solid. A blood clot that forms inside one of your veins or arteries is calle...

Causes
The cavernous sinus receives blood from veins of the face and brain. The blood drains it into other blood vessels that carry it back to the heart. This area also contains nerves that control vision and eye movements.
Cavernous sinus thrombosis is most often caused by a bacterial infection that has spread from the sinuses, teeth, ears, eyes, nose, or skin of the face.
You are more likely to develop this condition if you have an increased risk of blood clots.
Symptoms
Symptoms include:
- Bulging eyeball, usually on one side of face
- Cannot move the eye in a particular direction
- Drooping eyelids
- Headaches
- Vision loss
Exams and Tests
Tests that may be ordered include:
- CT scan of the head
- Magnetic resonance imaging (MRI) of the brain
- Magnetic resonance venogram
- Sinus x-ray
Treatment
Cavernous sinus thrombosis is treated with high-dose antibiotics given through a vein (IV) if an infection is the cause.
Blood thinners help dissolve the blood clot and prevent it from getting worse or recurring.
Surgery is sometimes needed to drain the infection.
Outlook (Prognosis)
Cavernous sinus thrombosis can lead to death if left untreated.
When to Contact a Medical Professional
Call your health care provider right away if you have:
- Bulging of your eyes
- Drooping eyelids
- Eye pain
- Inability to move your eye in any particular direction
- Vision loss
References
Chow AW. Infections of the oral cavity, neck, and head. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 64.
Markiewicz MR, Han MD, Miloro M. Complex odontogenic infections. In: Hupp JR, Ellis E, Tucker MR, eds. Contemporary Oral and Maxillofacial Surgery. 7th ed. Philadelphia, PA: Elsevier; 2019:chap 17.
Nath A, Berger JR. Brain abscess and parameningeal infections. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 385.
Sinuses - illustration
The sinuses are hollow cavities within the facial bones. Sinuses are not fully developed until after age 12. When people speak of sinus infections, they are most frequently referring to the maxillary and ethmoid sinuses.
Sinuses
illustration
Review Date: 1/25/2022
Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.