Cavernous sinus thrombosis

Synonyms and related keywords: CST, thrombosis of the cavernous intracranial sinus, cavernous sinus syndrome, cavernous sinus, cavernous sinuses, parasellar lesions, tumors, carotid artery aneurysms, carotid-cavernous fistulas, C-C fistulas, cavernous sinus thrombosis


 * The entity of cavernous sinus thrombosis has been recognized since Ribes described the entity at autopsy in 1825.
 * The classic description is of headache, papilledema, seizures, focal deficits, progressive coma and death with hemorrhagic infarction pathologically. In reality, most patients do not present with such serious illness, and if they survive tend to have a better prognosis than patients with arterial thrombosis.  The real trick is suspecting and making the diagnosis.

Pathophysiology & Etiology

 * Cerebral venous thrombosis usually leads to parenchymal infarction, though simple intracranial hypertension may be the only finding.
 * Venous infarction affects both the cortex and adjacent white matter, and are often hemorrhagic.
 * Association with subarachnoid hemorrhage, subdural hemorrhage, intracerebral hematoma
 * Classic presentation is extensive bilateral hemorrhagic infarcts in both superior and internal parts of both hemispheres due to thrombosis of the superior sagital sinus and its cortical veins.
 * Incidence is unknown, but is generally uncommon, ~0.08% of autopsies in one study.
 * Anatomy:
 * Cerebral veins --> Dural sinuses --> Internal jugular veins
 * The Cerebral veins include:
 * Superficial cerebral veins
 * Anatomy quite variable
 * Deep cerebral veins
 * Veins of the posterior fossa
 * The Dural sinuses most commonly affected by thrombosis are:
 * Superior sagital sinus
 * Drains most of cortex
 * Also fed by scalp emissary veins
 * Contains most of arachnoid villi responsible for draining CSF – obstruction increases intracerebral pressure
 * Superior sagital sinus thrombosis may only result in massive brain edema.
 * Lateral sinus
 * Drains cerebellum, brain stem, posterior cerebral hemispheres, middle ear
 * Near mastoid and inner ear, and susceptible to infections there
 * Cavernous sinus
 * Drains ophthalmic veins, anterior base of brain
 * Near, and susceptible to infection of face, sphenoid sinuses, teeth, and ear – infection (particularly with Staph aureus, fungus) is leading cause of cavernous sinus thrombosis, and cavernous sinus thrombosis is most common cerebral venous thrombosis.
 * Near oculomotor nerve, ophthalmic nerve, trigeminal nerve, abducens nerve, carotid artery and its surrounding sympathetic plexus.
 * Pathogenetic factors:
 * Venous stasis
 * Hypercoagulability
 * Vessel wall changes
 * Embolization

History and Symptoms

 * Presentation may be acute (<48h) in a third, subacute (48h – 30 days) in a third, or chronic (>30 days) in a third.
 * Patterns
 * Isolated intracranial hypertension
 * HA (headache)
 * Papilledema
 * Sixth nerve palsy
 * Mimicks pseudotumor cerebri, is most homogeneous presentation, and accounts for almost half of all presentations
 * HA is nonspecific, sometimes with vomiting
 * Focal cerebral signs
 * Quite heterogeneous, often reflecting focal areas of stroke, or seizure activity
 * Cavernous sinus syndrome
 * Chemosis
 * Proptosis
 * Painful ophthalmoplegia
 * CN III, IV, and VI findings
 * Unilateral or bilateral
 * Other
 * HA alone
 * Seizure
 * Psychiatric disturbance

MRI and CT

 * MRI with MR venography is the standard method of diagnosis at this time.
 * CT scanning was used in years past
 * Recent developments in CT venography may make it as good or better than MRV

Other Diagnostic Studies

 * EEG shows abnormalities in up to 75%, though these are not necessarily specific
 * Angiography – rarely used at this time
 * LP typically shows abnormalities in 90%: elevated pressure, elevated protein, red cells (65%), white cells (35%)

Risk Stratification and Prognosis

 * Prognosis better as diagnosis is increasing made with imaging instead of autopsy, with mortality rates down from 100% to 6.5% in a recent review of 76 patients.
 * Poor prognostic features:
 * Rapid progression
 * Coma
 * Extremes of age
 * Focal signs and symptoms
 * Hemorrhagic infarct
 * Serious underlying cause
 * Of note, if patient survives, outcome is better than for arterial infarct

Acute Pharmacotherapies

 * Antithrombotics
 * Anticoagulation
 * Standard treatment at this time, even if moderate intracranial hemorrhage present
 * Controversial in the past given risk of associated hemorrhage – one small randomized study with 20 patients in each arm showed a significant benefit making anticoagulation standard of care.
 * Thrombolysis – with agents like urokinase, TPA – generally given via microcatheters inserted for local infusion
 * Initial infusion sometimes followed by continuous infusion for a day or more until clot clears.
 * Many case reports of success, but not standard treatment at this time.
 * A study of 9 patients in Korea showed successful thrombolysis in all patients
 * Risk of hemorrhage
 * The literature suggests that it is mostly used now in severe cases with stupor, coma, rapidly progressing course, or severely raised ICP, and only in centers experienced in the methodology. Its role may expand with more experience.
 * Surgical thrombectomy – not generally performed anymore
 * Antieleptics – as indicated
 * Antibiotics – if infectious precipitant
 * Intracranial pressure manipulation
 * Medical: mannitol, steroids, acetazolamide, repeat LPs
 * Shunt

Acknowledgements
The content on this page was first contributed by: C. Michael Gibson M.S., M.D.