Dural venous sinus thrombosis (DVST) is a rare form of cerebrovascular accident, which is a deterioration in the outflow of blood from the brain due to blockage of the sinuses by blood clots (thrombi). It results as headache, visual impairment, hemiparesis of the face or extremities, convulsions, etc. The diagnosis is established on the basis of computed tomography or magnetic resonance imaging with intravenous contrast enhancement, allowing visualization of venous sinus obstruction by a thrombus. DVST is treated with anticoagulants, less often with thrombolytics. Since this pathology is usually a complication of another disease, an additional examination may be required. Venous sinus thrombosis can be complicated by intracranial hypertension, which in some cases requires surgery (eg, bypass grafting).
Where are the dural sinuses located?
The dural venous sinuses (also known as dural sinuses, cerebral sinuses, or cranial sinuses) are venous channels located between the endosteal and meningeal layers of dura mater in the brain.
Signs and symptoms
The initial symptoms of cavernous sinus thrombosis are severe headaches or facial pains, which usually occur on only one side and are localized in the postorbital and frontal regions. High fever is also common. Later, ophthalmoplegia develops (usually due to the involvement of the 6th pair of cranial nerves at the initial stage), exophthalmos and eyelid edema, these manifestations are often noted on both sides. Also, the sensitivity of the facial skin may decrease or completely disappear. Signs of DVST progression are impaired consciousness, disorientation, seizures, and focal neurological symptoms. Patients with cavernous sinus thrombosis may have anisocoria or mydriasis (dysfunction of the third pair of cranial nerves), papilledema, and loss of vision.
- MRI or CT
Because the condition is rare, the diagnosis of cavernous sinus thrombosis is often difficult. It should be suspected in all patients with signs of orbital cellulitis. Thrombosis of the cavernous sinus can be distinguished if the patient has a lesion of the cranial nerves, bilateral involvement of the eyes in the pathological process, as well as changes in mental status.
The gold standard for diagnosing DVST is neuroimaging. MRI is preferred, but CT is also acceptable. Additional informative tests may include blood culture and lumbar puncture.
The mortality rate among patients with cavernous sinus thrombosis is 30%, and 50% in patients with sphenoidal sinusitis. Moreover, 30% of patients develop serious and, in some cases, irreversible complications (for example, ophthalmoplegia, blind-ness, post-stroke disorders, pituitary insufficiency).
- Intravenous administration of high doses of antibiotics;
Initial antibiotic therapy for patients with cavernous sinus thrombosis includes nafcillin or oxacillin 1 to 2 g once every 4 to 6 hours in combination with a 3rd generation cephalosporin (eg, ceftriaxone 1 g every 12 hours). In areas where methicillin-resistant S. aureus strains predominate, intravenous vancomycin in a dosage of 1 g 1 time every 12 hours should be replaced with nafcillin or oxacillin. If the patient has concomitant sinusitis or a dental infection, then an anti-anaerobic drug (for example, metronidazole 500 mg every 8 hours) should be added to therapy.
In the presence of preexisting sphenoidal sinusitis, sinus drainage is recommended, especially if an adequate response to antibiotics has not been obtained within 24 hours.
Adjunctive therapy for cavernous sinus thrombosis for cranial nerve lesions may include corticosteroids (for example, dexamethasone 10 mg once intravenously or orally every 6 hours), anticoagulation therapy is contraindicated in most cases because the response to antibiotics is usually adequate and the risk of developing complications outweigh the possible benefits of such treatment.