Cerebral Venous Thrombosis
Evie Marcolini MD, Anand Swaminathan MD
- Cerebral Venous Thrombosis (CVT) is an uncommon, serious cause of headache.
- CVT comprises 1% of all strokes.
- Risk Factors
- Oral contraceptive pills
- Hormone replacement therapy
- Pregnancy/postpartum (up to 6 weeks)
- Malignancy (particularly hematological)
- Inflammatory diseases (eg, lupus)
- Head/neck infections
- Recent neurosurgical procedure
- Presentation
- New or unique persistent headache
- Insidious or acute in onset
- Increases with movements that increase intracranial pressure such as bending over or coughing
- Three categories of symptoms/signs:
- Increased intracranial hypertension
- Papilledema
- Nausea/vomiting
- Visual disturbances
- Focal syndromes
- Encephalopathic syndromes (more common with deep sinus involvement)
- Non-contrast head CT (NCHCT)
- Only ⅓ of CVT will show up on NCHCT
- CT findings in CVT include:
- Delta sign: hyperdensity of posterior superior sagittal sinus
- Venous infarct (spans more than one arterial territory) (very specific)
- Diffuse cerebral edema
- Hydrocephalus
- Secondary subarachnoid hemorrhage
- CT venogram or MRI/MR venogram
- These are considered “gold standard” for CVT.
- CT venogram performs as well as MRI/MRV in most cases.
- However, in patients with signs of deep cerebral vein involvement (encephalopathy, altered mental status) MRI/MRV is superior.
- Discuss with your radiologist to help make best imaging decision in your facility
- Treatment
- Consult neurology and neurosurgery
- Heparinization: unfractionated or LMWH
Thomas K. - February 6, 2021 5:56 AM
Thank you for this discussion. I have seen 2 of these cases in the last 3 years, both were associated with head/neck infections. The patients had severe headaches and the sinus thrombosis was found on CT angio of the brain. I had ordered the test to look for aneurysm since the patient had severe headache and severe photophobia and neck pain. The non-contrast head CT found severe sinusitis and the CT angio brain showed lack of contrast in the sinus which lead to the diagnosis. Can CT angio be used to make this diagnosis, or did I just get lucky with these 2 cases?
Evie M. - February 6, 2021 7:20 AM
Hi Thomas, and thanks for your comments. It's interesting - digital subtraction angiography historically was the test of choice for venous lesions - looking for a filling defect in the sinuses, delayed emptying or dilated collateral circulation, but now the gold standard is CTV or MRI/MRV, since DSA is invasive and limited by anatomic variations of the venous sinus system.
With CTA, I imagine some of these findings may present, but it's not as sensitive as CTV or MRI/MRV. When I have ordered a noncontrast CT, and am considering venous in the DDX, I will have a conversation with the radiologist to see if there are any subtle signs that corroborate my consideration for venous imaging. The noncontrast CT can have a 'triangle sign', which is a density seen in the venous space, present in only 1/3 of cases of CVT. If, by chance I have ordered a CT with contrast (different from CTA), there may be an 'empty delta sign', which is a triangular area of enhancement with a low attenuating center, suggesting a thrombosed sinus.
If I am reading into your cases correctly, I think you (and the patient) got lucky! since the diagnosis of CVT is often delayed.