The figure above shows a coronal source image (left) and a
3D-reconstructed image (right) from a magnetic resonance venography
(MRV) study. It demonstrates a classic example of a dural venous sinus thrombosis (DVST) with a flow void (a filling defect in the venous sinus where hyperintense flow should be seen) in the right transverse sinus.
DVST is one of the more common mimickers of pseudotumor cerebri
and often presents acutely with one or more of the following: headache,
blurred vision, papilledema, transient visual obscurations, and
unilateral / bilateral sixth nerve palsy. More rarely, DVST can cause
intracranial hemorrhage and stroke. Before the advent of non-invasive
venography (MRV and CTV), many patients with DVST were misdiagnosed as
having pseudotumor cerebri. In fact, an MRV or CTV (in addition to a
brain CT or MRI) should be performed in any patient with bilateral
papilledema who does not fit the typical pseudotumor cerebri profile (overweight female of childbearing age).
DVST, similar to deep venous thrombosis or pulmonary embolism, can be precipitated by acquired or hereditary hypercoaguability. The common DVST associated hypercoaguable states include pregnancy (and the peripartum period), oral contraceptive use, lupus, inherited coagulopathies, infection, dehydration, and acute head injury (not a remote history). Any infection will increase the risk for DVST although middle / inner ear infections and meningitis are among the more common precipitating infections.
Patients with DVST but without a clear hypercoaguable risk factor
should be considered for a hypercoaguable laboratory evaluation and/or
referral to a hematologist.
