Cerebral Venous Sinus Thrombosis

Cerebral venous sinus thrombosis (CVST) presents with progressive headache, papilledema, changes in mental status, focal neurologic deficits, and/or seizures. Obstructed venous drainage causes venous congestion, resulting in cerebral edema, hemorrhage, or ischemia if the arterial pressure cannot overcome the venous pressure (venous infarction). CVST is often overlooked in patients with progressively worsening unexplained headache and young patients with lobar hemorrhage. Early identification is critical, as when unrecognized, progression and neurologic deterioration are common. Note that intracerebral hemorrhage due to CVST is the rare hemorrhagic condition in which anticoagulation is indicated. This reflects the fact that hemorrhage is due to venous outflow obstruction, not arterial bleeding. Hyperdensity in the sinuses on noncontrast computed tomography (CT) may suggest the diagnosis, but brain magnetic resonance imaging (MRI) with contrast and/or MR venography is usually necessary; CT venography is an alternative.

A.

Anticoagulation is necessary regardless of the presence or absence of hemorrhage. If hemorrhage is present, it is reasonable to start therapeutic intravenous heparin because of its rapid reversibility and the ability to closely monitor anticoagulant levels. In the absence of hemorrhage, low-molecular-weight heparin (LMWH) may be more convenient and is likely of similar efficacy. Direct oral anticoagulants (DOACs) can also be considered once clinical stability is apparent.
B.

With clinical deterioration and progressive edema despite therapeutic anticoagulation, consider endovascular therapy to mechanically remove venous sinus clot. Hyperosmolar therapy should also be considered when edema is severe, particularly as a bridge to endovascular therapy. Because of the high risk of seizures, continuous electroencephalogram monitoring is reasonable in patients with progressive symptoms or depressed mental status.
C.

With clinical deterioration and worsening hemorrhage despite therapeutic anticoagulation, consider endovascular therapy as mentioned above. In rare cases of focal hematoma expansion causing herniation (i.e., temporal lobe hemorrhage), decompressive surgery can be considered. However, surgery necessitates temporary cessation of anticoagulation, which may result in worsening venous congestion and infarction.
D.

Determine the underlying etiology of CVST to guide choice of optimal treatment, including duration and type of anticoagulant therapy. If intravenous heparin or LMWH was initially administered, this can be transitioned to an oral agent (DOAC or warfarin), assuming that medication is appropriate for the particular patient and underlying etiology.
E.

During pregnancy and the postpartum period, there is an elevated risk of venous thrombosis. LMWH is the treatment of choice in pregnancy, although initial heparin use is also reasonable. Warfarin should be avoided in pregnancy due to teratogenicity. Hypercoagulability typically persists several weeks after delivery, so treatment is recommended to continue at least 6 weeks postpartum.
F.

Both LMWH and DOACs are reasonable for hypercoagulability of malignancy. If cancer treatment is curative, consider discontinuing anticoagulation eventually.
G.

When CVST is unprovoked and without clear cause, life-long anticoagulation is generally recommended although there is little data specific to CVST.
H.

Oral contraceptive pills increase the risk of venous thrombosis, a risk that is compounded with age and smoking. A nonhormonal intrauterine device is the ideal alternative birth control plan, although some second-generation progesterone OCPs may not carry a risk of venous thrombosis. Similarly, estrogen supplementation contributes to venous thrombosis, in which case it should be stopped immediately. Some chemotherapeutic agents may also cause venous thrombosis and should be avoided.
I.

If CVST occurs in the context of a high-risk thrombophilia, life-long oral anticoagulation is warranted. Choice of optimal anticoagulant agent (i.e., warfarin vs. DOAC) should be made in discussion with an expert in disorders of coagulation. With antiphospholipid syndrome, warfarin is preferred; DOACs may be appropriate in other scenarios.
J.

Repeat venous imaging, typically with MR venography, should be repeated in 3–6 months to evaluate for recanalization of the venous sinuses and to establish a baseline study for comparison in the future should new or recurrent symptoms develop. Incomplete recanalization is not uncommon and generally well tolerated.