Does CVT Come Under CVA?
Yes, cerebral venous thrombosis (CVT) is classified as an uncommon form of stroke (CVA), representing 0.5-1% of all strokes, but it differs fundamentally from typical arterial strokes in its pathophysiology, presentation, and management. 1, 2
Key Distinctions from Arterial Stroke
While CVT falls under the broader category of cerebrovascular accidents, it has critical differences:
Pathophysiology: CVT results from thrombosis in cerebral veins or dural sinuses causing impaired venous drainage and increased intracranial pressure, whereas arterial stroke results from arterial occlusion or rupture 2
Demographics: CVT predominantly affects younger individuals (78% under age 50) and women, particularly those on oral contraceptives or pregnant/postpartum, unlike typical arterial strokes 1, 2
Presentation pattern: CVT has a more subacute presentation with slower symptom progression (56% subacute, 37% acute, 7% chronic) compared to the sudden onset typical of arterial stroke 2
Clinical features: Seizures occur in approximately 40% of CVT patients versus much lower rates in arterial stroke; bilateral brain involvement is more common in CVT 2
Management of Cerebral Venous Thrombosis
Diagnostic Approach
MRI with MR venography is the preferred diagnostic modality for CVT, showing both venous occlusion and parenchymal changes. 1, 2
Imaging Strategy:
- First-line: MRI T2*-weighted imaging + MRV 1
- Alternative: CT/CTV if MRI not readily available 1
- Important caveat: Non-contrast CT has limited sensitivity (abnormal in only 30% of cases) and normal CT does not exclude CVT 2, 3
Diagnostic Pitfalls to Avoid:
- Median delay from symptom onset to diagnosis is 7 days due to variable presentation 2
- CVT may be misdiagnosed as idiopathic intracranial hypertension when presenting with isolated headache and papilledema 2
- D-dimer can help exclude CVT when negative but has poor specificity 2
Acute Management Algorithm
Initiate anticoagulation (IV heparin or SC low molecular weight heparin) immediately upon diagnosis if no major contraindications, even in the presence of intracranial hemorrhage. 1, 2
Initial Treatment:
- Anticoagulation is the mainstay: IV heparin or subcutaneous LMWH 1, 2
- Critical distinction: Intracranial hemorrhage that occurred as a consequence of CVT is NOT a contraindication for anticoagulation 1
Management Based on Clinical Course:
If neurologically stable or improving:
- Continue oral anticoagulation for 3-12 months based on underlying etiology 1
- Transient reversible factor: 3-6 months
- Low-risk thrombophilia: 6-12 months
- High-risk inherited thrombophilia: Consider lifelong anticoagulation 1
If neurological deterioration occurs:
- With severe mass effect or ICH: Consider decompressive hemicraniectomy (lifesaving procedure) 1, 2
- With no or mild mass effect on repeated imaging: May consider endovascular therapy with or without mechanical disruption 1
- Endovascular therapy indications: Patients with absolute contraindications for anticoagulation or failure of initial therapeutic doses of anticoagulant therapy 1
Risk Factor Assessment
Screen for prothrombotic conditions in all CVT patients, as 34% have an inherited or acquired prothrombotic condition. 1
Key Risk Factors to Evaluate:
- Inherited thrombophilias: protein C deficiency (OR 11.1), protein S deficiency, antithrombin III deficiency, factor V Leiden 1, 2
- Acquired risks: oral contraceptives, pregnancy/puerperium, malignancy, inflammatory conditions 1, 2
- Antiphospholipid syndrome 1
Common Management Pitfalls
- Do not withhold anticoagulation due to hemorrhagic transformation: This is a consequence of CVT itself and anticoagulation prevents thrombus propagation 1, 2
- Do not rely on non-contrast CT alone: Pursue CTV or MRV when clinical suspicion is high despite normal CT 2
- Do not delay treatment: Anticoagulation should be initiated as soon as diagnosis is confirmed 1