What is the recommended management of cerebral venous thrombosis, including anticoagulation regimen, seizure control, intracranial pressure measures, and treatment duration?

Management of Cerebral Venous Thrombosis

Immediate Anticoagulation

All patients with cerebral venous thrombosis should receive immediate therapeutic anticoagulation with either low-molecular-weight heparin (LMWH) or intravenous unfractionated heparin (UFH), even when intracranial hemorrhage is present on imaging. 1, 2

• The presence of hemorrhagic venous infarction or subarachnoid hemorrhage related to CVT is NOT a contraindication to anticoagulation - this is a critical point where withholding anticoagulation represents a clinical error that can lead to thrombus propagation and death. 3, 1

Initial Anticoagulation Regimen

LMWH is preferred over UFH due to superior efficacy: 1

• Enoxaparin: 1.0 mg/kg subcutaneously twice daily OR 1.5 mg/kg once daily 1
• Dalteparin: 200 units/kg subcutaneously once daily 1

UFH is appropriate when: 1

• LMWH is contraindicated or unavailable
• Severe renal failure (creatinine clearance <30 mL/min) is present
• Thrombolytic therapy may be needed
• Dosing: 5000 IU bolus, then continuous infusion of approximately 30,000 IU over 24 hours, adjusted to maintain aPTT at 1.5-2.5 times baseline 1

Seizure Management

• Treat seizures aggressively when they occur - seizures are common in CVT and require immediate antiepileptic therapy. 3, 1
• All patients require monitoring for seizure activity as part of supportive care. 3, 2

Intracranial Pressure Management

• Monitor closely for signs of elevated intracranial pressure: worsening consciousness, new focal deficits, progressive headache, papilledema. 1, 2
• Antiedema treatment should be used as life-saving interventions when severe mass effect is present, including hyperventilation, osmotic diuretics (mannitol, hypertonic saline), and consideration of decompressive hemicraniectomy. 4
• Decompressive hemicraniectomy is indicated for: severe mass effect causing progressive neurological deterioration, large intracerebral hemorrhage with midline shift, or life-threatening herniation. 1

Monitoring and Clinical Deterioration

• Perform serial neurological examinations every 2-4 hours during the first 24 hours to detect deterioration. 1
• Obtain repeat non-contrast CT at 24-48 hours after initiating anticoagulation to assess for hematoma expansion. 1
• Regular neurological assessment is necessary throughout the treatment course to identify patients requiring escalation of care. 3, 2

Escalation Therapies for Treatment Failure

Endovascular therapy (mechanical thrombectomy with or without local thrombolysis) should be considered when: 3, 1

• Absolute contraindications to anticoagulation exist
• Initial therapeutic anticoagulation fails (progressive neurological decline despite adequate treatment)
• Shock is likely to cause death before systemic anticoagulation can take effect

Note: Systemic thrombolysis is not routinely recommended due to insufficient evidence and increased bleeding risk, but may be considered in highly selected cases without intracranial hemorrhage who deteriorate despite adequate anticoagulation. 4

Transition to Oral Anticoagulation

• Begin oral anticoagulants early while continuing parenteral anticoagulation for a minimum of 5 days AND until INR ≥2.0 for at least 24 hours. 1
• For vitamin K antagonists (warfarin): target INR 2.0-3.0 (goal 2.5). 1
• Direct oral anticoagulants (DOACs) are acceptable alternatives to warfarin, though evidence is more limited. 5

Duration of Anticoagulation (Treatment Phase and Beyond)

Minimum duration is 3 months for all patients. 3, 1 The total duration depends on the underlying etiology:

• Provoked CVT (transient risk factor such as infection, trauma, surgery): 3-6 months 3, 1
• Unprovoked (idiopathic) CVT or mild thrombophilia: 6-12 months 1, 4
• Recurrent CVT, venous thrombosis after CVT, or severe thrombophilia: indefinite anticoagulation with INR 2-3 3, 1
• Antiphospholipid syndrome: consider indefinite anticoagulation 1
• Cancer-associated CVT: continue anticoagulation as long as anti-cancer treatment is given 1

Special Populations

Behçet's syndrome with CVT: 1

• High-dose glucocorticoids followed by tapering
• Add anticoagulants for short duration

Severe renal failure (CrCl <30 mL/min): 1

• UFH followed by early vitamin K antagonists, OR
• LMWH adjusted to anti-Xa concentration

Mechanical heart valves, antiphospholipid syndrome, or severe renal impairment: 1

• Warfarin is preferred over DOACs

Vaccine-Induced Thrombotic Thrombocytopenia (VITT)

If VITT-related CVT is suspected: 1

• Administer intravenous immunoglobulin (IVIG) 1 g/kg immediately
• Use non-heparin anticoagulants (DOACs, fondaparinux, danaparoid, or argatroban) due to cross-reactivity risk with heparin-induced thrombocytopenia
• Start therapeutic anticoagulation as soon as possible after assessing bleeding risk, even with intracerebral hemorrhage present
• Note: Normal platelet counts do NOT exclude VITT - approximately 5% of VITT patients present with initially normal platelets

Follow-up Imaging

• CT venography or MR venography at 3-6 months after diagnosis is reasonable to assess for recanalization of occluded sinuses in stable patients. 1, 2
• Duration of anticoagulation is NOT determined by presence or absence of radiographic recanalization. 1

Critical Pitfalls to Avoid

• Never withhold anticoagulation due to hemorrhage on imaging - hemorrhagic venous infarction is an indication FOR anticoagulation, not against it. 1
• Do not delay anticoagulation - immediate initiation is essential even with intracranial hemorrhage. 1, 2
• Check for drug interactions with DOACs - strong P-glycoprotein or CYP3A4 inhibitors can increase DOAC levels significantly. 5
• Avoid combining anticoagulation with antiplatelet agents without compelling indication - this significantly increases bleeding risk. 5
• Perform serial platelet counts throughout anticoagulation to detect heparin-induced thrombocytopenia. 1
• DOACs are contraindicated in pregnancy - counsel women of childbearing age about contraception. 5