Cavernous Sinus Thrombosis

Medically Reviewed by Christopher Melinosky, MD on April 14, 2022

Cavernous sinus thrombosis is a very rare, life-threatening condition that can affect adults and children.

In cavernous sinus thrombosis, a blood clot blocks a vein that runs through a hollow space underneath the brain and behind the eye sockets. These veins carry blood from the face and head back to the heart.

The cause of cavernous sinus thrombosis is usually an infection. But other factors may play a role.

Cavernous sinus thrombosis is a serious condition. It causes death in up to 30% of cases.

Symptoms of cavernous sinus thrombosis may include:

  • Severe headache often accompanied by tearing
  • Swelling, redness, or irritation around one or both eyes
  • Drooping eyelids
  • Inability to move the eye
  • High fever
  • Pain or numbness around the face or eyes
  • Fatigue
  • Vision loss or double vision
  • Seizures
  • Altered mental status that can range from confusion to coma

Double vision and seizures are rare.


Cavernous sinus thrombosis is typically caused by an infection that has spread beyond the face, sinuses, or teeth. Less commonly, infections of the ears or eyes may cause cavernous sinus thrombosis.

To contain the infection, the body's immune system creates a clot to prevent bacteria or other pathogens from spreading. The clot increases pressure inside the brain. This pressure can damage the brain and may ultimately cause death.

Rarely, cavernous sinus thrombosis may also be caused by a severe blow to the head.

Cavernous sinus thrombosis is more common in people who take certain medications such as oral contraceptives or who have underlying health conditions such as uncontrolled diabetes or cancer that may increase their risk for blood clots.

Doctors may order brain scans, including CT and MRI scans, to look for cavernous sinus thrombosis. They may also test blood or spinal fluid to check for signs of infection.

Corticosteroid medications may also be used to reduce swelling. Blood thinners are sometimes given.

Doctors treat cavernous sinus thrombosis with high-dose antibiotics if they find an underlying infection. These are usually given through an IV drip.

Surgery may be needed to drain the site of the initial infection.

Show Sources


Aderman, C. "Cavernous Sinus Thrombosis," Beth Israel Deaconess Medical Center and Harvard University, April 2011.

Filippidis, A. Neurosurgery Focus, November 2009.

The Merck Manual for Healthcare Professionals: "Cavernous Sinus Thrombosis."

National Health Service Direct Encyclopedia: "Cavernous Sinus Thrombosis."

Zimmer, J. The Internet Journal of Pediatrics and Neonatology, Feb. 5, 2012.

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