Cavernous Sinus Thrombosis - Causes, Symptoms & Treatment

Cavernous sinus thrombosis is the formation of a blood clot within the cavernous sinus. The cavernous sinus is a cavity at the base of the brain that contains a vein, several nerves, and other structures. The vein carries deoxygenated blood from the brain and face back to the heart. Cavernous sinus thrombosis is rare. Bacterial infections caused by Streptococcus and Staphylococcus are the most common organisms found in patients with cavernous sinus thrombosis.

Before antibiotics were discovered, the mortality from cavernous sinus thrombosis was 80% to 100%. Since the discovery of antibiotics, the mortality ranges between 20% and 30%. The cavernous sinus is an important structure because of its location and its contents which include the third cranial (oculomotor) nerve, the fourth cranial (trochlear) nerve, parts 1 (the ophthalmic nerve) and 2 (the maxillary nerve) of the fifth cranial (trigeminal) nerve, and the sixth cranial (abducens) nerve. A thrombosis (clot) in this key crossroads causes the cavernous sinus syndrome which is characterized by edema (swelling) of the eyelids and the conjunctivae of the eyes and paralysis of the cranial nerves which course through the cavernous sinus.

Cavernous sinus thrombosis is septic thrombosis of the cavernous sinus, usually caused by bacterial sinusitis. Symptoms and signs include pain, exophthalmos, ophthalmoplegia, vision loss, papilledema, and fever. Diagnosis is confirmed by CT or MRI. Treatment is with IV antibiotics. Complications are common, and prognosis is poor.

Cavernous sinus thrombosis is the blockage of a large vein at the base of the brain (the cavernous sinus) which causes a blood clot to form. The cavernous sinuses are situated within the skull, immediately behind each eye socket and on either side of the pituitary gland . As well as containing blood , the cavernous sinuses are surrounded by sets of nerves called the cranial nerves. These nerves are necessary to control eye movement and for the feeling in the top and middle part of your head and face. Any infection in this area, such as from a pimple or boil in the nostril or on the upper lip or nose, may cause a local tissue inflammation known as cellulitis. From this local inflammation , infection may spread and reach one of the cavernous sinuses. If this happens, the blood in the sinus may turn to an infected clot.

Causes of Cavernous Sinus Thrombosis

The cause of cavernous sinus thrombosis is usually a bacterial infection that has spread from the sinuses, ears, eyes, nose, or skin of the face. The majority of cases are cause by Streptococcal and Staphylococcal bacterial infections. Another common cause of spread of infection into a cavernous sinus is from squeezing a pimple or boil on the nose or just inside a nostril.

• Most cases of septic CST are due to an acute infection in an otherwise healthy individual. However, patients with chronic sinusitis or diabetes mellitus may be at a slightly higher risk.
• The causative agent is generally Staphylococcus aureus, although streptococci, pneumococci, and fungi may be implicated in rare cases.

Signs and Symptoms of Cavernous Sinus Thrombosis

Sign and symptoms may include the following :

• High fever .
• Seizures.
• Drooping eyelids.
• Stiff neck .
• Muscle weakness.
• Rapid heart rate.
• Loss of vision .
• Drowsiness or coma.
• Numbness in the face .
• Inability to move one's eye in a particular direction .

Treatment for Cavernous Sinus Thrombosis

The condition can be easily treated with high doses of intravenous antibiotic drugs which are given immediately after diagnosis. Sometimes surgical intervention is needed to drain the infected sinuses. Commonly used antibiotics include the penicillins, the cephalosporins, and metronidazole. You may also be placed on a blood thinner called heparin, but this remains controversial and the decision is made between you and your physician. Some treatment methods of Cavernous Sinus Thrombosis.

• Antibiotics are recommended for a minimum of 3-4 weeks.
• The condition can be easily treated with high doses of intravenous antibiotic drugs which are given immediately after diagnosis. 
• Commonly used antibiotics include the penicillins, the cephalosporins, and metronidazole.
• Once the diagnosis of cavernous sinus thrombosis is established, intravenous antibiotics are administered to treat the infection.
• Surgical drainage of an infected sphenoid sinus is recommended when this is the cause of cavernous sinus thrombosis.