From the Guidelines
Cerebral venous sinus thrombosis (CVST) is a rare form of stroke caused by blood clots forming in the brain's venous sinuses, and its diagnosis and management should prioritize early anticoagulation and imaging confirmation with MRI or CT venography. The most common causes of CVST include prothrombotic conditions such as Factor V Leiden mutation, protein C and S deficiencies, antithrombin III deficiency, and antiphospholipid syndrome 1. Hormonal factors, particularly oral contraceptive use, pregnancy, and the postpartum period, also play a significant role in the development of CVST. Infections, especially of the ear, face, or neck, can extend to the venous sinuses, while other causes include dehydration, inflammatory conditions like lupus and inflammatory bowel disease, malignancies, trauma, and certain medications such as high-dose steroids 1.
Causes of CVST
- Prothrombotic conditions: Factor V Leiden mutation, protein C and S deficiencies, antithrombin III deficiency, and antiphospholipid syndrome
- Hormonal factors: oral contraceptive use, pregnancy, and the postpartum period
- Infections: especially of the ear, face, or neck
- Dehydration
- Inflammatory conditions: lupus and inflammatory bowel disease
- Malignancies
- Trauma
- Certain medications: high-dose steroids
Investigations for CVST
- MRI with venography: gold standard for diagnosis
- CT venography: faster alternative when MRI is unavailable
- Laboratory tests: complete blood count, coagulation profile, D-dimer (often elevated), and thrombophilia screening
- Lumbar puncture: if meningitis is suspected, typically showing increased opening pressure and possibly blood in the cerebrospinal fluid
- Electroencephalography: to evaluate seizure activity, which is common in CVST
Early diagnosis and treatment with anticoagulation are crucial in improving outcomes and reducing mortality and long-term neurological deficits in CVST patients. According to the American Heart Association/American Stroke Association guidelines, a venographic study (either CTV or MRV) should be performed in suspected CVT if the plain CT or MRI is negative or to define the extent of CVT if the plain CT or MRI suggests CVT 1. Additionally, early follow-up CTV or MRV is recommended in CVT patients with persistent or evolving symptoms despite medical treatment or with symptoms suggestive of propagation of thrombus.
From the Research
Causes of Cerebral Venous Sinus Thrombosis (CVST)
- The causes of CVST can be attributed to various risk factors, including the use of oral contraceptive pills, chronic sinuses or ear infections, and obesity 2.
- Isolated antithrombin III deficiency has also been identified as a rare cause of CVST 3.
- Other contributing factors may include pregnancy, postpartum period, and anemia 4.
Investigations of CVST
- Diagnosis of CVST can be challenging due to non-specific clinical and radiological features, and a high index of suspicion is required 2, 3.
- Imaging studies such as computed tomography (CT) scan, magnetic resonance imaging (MRI), and magnetic resonance venography (MRV) are essential for diagnosis 2, 5, 4.
- MRI and MRV are considered the modalities of choice for accurate diagnosis, as they can reveal occlusion at two or more venous sinus sites 2, 4.
- Laboratory studies, including a thorough history and ophthalmoscopic examination, are also important in the evaluation and diagnosis of CVST 3.
Clinical Presentation
- The most common presenting symptoms of CVST include headache, focal neurologic deficits, seizures, and altered sensorium 2, 4, 6.
- Patients may also present with bilateral papilledema, numbness, weakness, aphasia, and head injury 3, 6.
- A high index of suspicion is necessary to diagnose CVST, particularly in patients without apparent risk factors 3.