Cavernous sinus thrombosis is a very rare, typically septic thrombosis of the cavernous sinus, usually caused by nasal furuncles or bacterial sinusitis. Symptoms and signs include pain, proptosis, ophthalmoplegia, vision loss, papilledema, and fever. Diagnosis is confirmed by CT or MRI. Treatment is with IV antibiotics. Complications are common, and prognosis is guarded.
Etiology of Cavernous Sinus Thrombosis
The cavernous sinuses are trabeculated sinuses located at the base of the skull that drain venous blood from facial veins. Cavernous sinus thrombosis is an extremely rare complication of common facial infections, most notably nasal furuncles (50%), sphenoidal or ethmoidal sinusitis (30%), and dental infections (10%). Most common pathogens are Staphylococcus aureus (70%), followed by Streptococcus species; anaerobes are more common when the underlying condition is dental or sinus infection.
Thrombosis of the lateral sinus (related to mastoiditis) and thrombosis of the superior sagittal sinus (related to bacterial meningitis) occur but are rarer than cavernous sinus thrombosis.
Pathophysiology of Cavernous Sinus Thrombosis
The 3rd, 4th, and 6th cranial nerves and the ophthalmic and maxillary branches of the 5th cranial nerve are adjacent to the cavernous sinus and are commonly affected in cavernous sinus thrombosis. Complications of cavernous sinus thrombosis include meningoencephalitis, brain abscess, stroke, blindness, and pituitary insufficiency.
Symptoms and Signs of Cavernous Sinus Thrombosis
Initial symptoms of cavernous sinus thrombosis are progressively severe headache or facial pain, usually unilateral and localized to retro-orbital and frontal regions. High fever is common. Later, ophthalmoplegia (typically the 6th cranial nerve in the initial stage, which may be associated with Horner syndrome), proptosis, and eyelid edema develop and often become bilateral. Facial sensation may be diminished or absent. Decreased level of consciousness, confusion, seizures, and focal neurologic deficits are signs of central nervous system (CNS) spread. Patients with cavernous sinus thrombosis may also have anisocoria or mydriasis (3rd cranial nerve dysfunction), papilledema, and vision loss.
Diagnosis of Cavernous Sinus Thrombosis
MRI or CT
Cavernous sinus thrombosis is often misdiagnosed because it is rare. It should be considered in patients who have signs consistent with orbital cellulitis. Features that distinguish cavernous sinus thrombosis from orbital cellulitis include cranial nerve dysfunction, bilateral eye involvement, and mental status changes.
Diagnosis is based on neuroimaging. MRI is the better study, but CT is also helpful. Contrast-enhanced MR venogram (MRV) and CT venogram are more sensitive than either CT or MRI. Useful adjunct testing may include blood cultures and lumbar puncture.
Prognosis for Cavernous Sinus Thrombosis
Mortality in the antibiotic era is about 15 to 20%. An additional 40% develop serious sequelae (eg, ophthalmoplegia, blindness, stroke, pituitary insufficiency), which may be permanent.
Treatment of Cavernous Sinus Thrombosis
IV high-dose antibiotics
Sometimes corticosteroids
Sometimes anticoagulation
S. aureus
In cases with underlying sphenoid sinusitis, surgical sinus drainage is indicated, especially if there is no clinical response to antibiotics within 24 hours.
More Information
The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
Plewa MC, Tadi P, Gupta M: Cavernous sinus thrombosis. StatPearls Publishing, Treasure Island, 2020.
