Makindo Medical Notes

Related Subjects: Thrombophilia testing |Antiphospholipid syndrome |Protein C Deficiency |Protein S Deficiency |Prothrombin 20210A mutation |Factor V Leiden Deficiency |Antithrombin III deficiency (AT3) |Cerebral Venous Sinus thrombosis |Budd-Chiari syndrome

Cerebral Venous Sinus Thrombosis (CVST) — the postpartum period is a risk factor for cortical vein and sinus thrombosis. The combination of CVST and thrombocytopenia has been identified very rarely in those receiving COVID-19 vaccination.

About

• Likely underdiagnosed, and many cases go untreated.
• Headache, papilledema, and a normal CT may indicate CVST.
• Consider in pregnant women or recent pregnancy.

Aetiology

• Any procoagulant condition or localized infections.
• Oral contraceptive pills (OCP), pregnancy, or postpartum period.
• Hyperviscosity syndromes, smokers.
• Dehydration, use of ecstasy tablets.
• Behçet's disease, ulcerative colitis, Crohn's disease.
• Localized mastoid, ear, or sinus infections.
• Malignancy: adenocarcinoma.
• Hematological conditions: polycythemia vera, thrombocythemia, leukemia, sickle cell disease.
• Direct cranial trauma, neurosurgical procedures near a venous sinus.
• Bacterial meningitis.
• Antiphospholipid antibody syndrome.
• Factor V Leiden, protein S and protein C deficiencies.
• Prothrombin mutation and hyperhomocysteinemia.

Venous Anatomy

Anatomy of the Thrombosis in Order of Occurrence

• Superior sagittal sinus: raised intracranial pressure (ICP), headaches.
• Lateral sinuses, straight sinus, and Galenic system: can cause bilateral massive deep infarction affecting thalami with akinetic mutism.
• Thrombosis of small cortical veins: cortical vein thrombosis.
• Cavernous sinus: may lead to cavernous sinus syndrome.
• Cortical veins: localized venous infarction and focal cortical signs.
• These all drain into the right and left internal jugular veins.

Pathophysiology

• Venous thrombosis leads to edema and infarction.
• Reduced CSF drainage with increased ICP.
• Congested, edematous, hemorrhagic infarcts.
• Subarachnoid bleeding may be seen.

Clinical Presentation

• Isolated headache or increased ICP (present in ~90% of cases).
• Focal neurological presentations, subacute encephalopathy.
• Cavernous sinus syndrome/multiple cranial neuropathies.
• Headache, nausea, vomiting, neck stiffness, malaise.
• Cortical vein occlusion gives expected localizing signs.
• Dural sinus involvement: raised ICP, sudden headache.
• Declining consciousness, coma, seizures.
• Neurological deficits similar to stroke, papilledema, sixth nerve palsy.
• Atypical presentations: psychosis, subarachnoid hemorrhage (SAH), cranial nerve palsies, transient ischemic attack (TIA), and migraine.

Differential Diagnosis

• Idiopathic intracranial hypertension; need to exclude CVST, especially if male or non-obese.

Investigations

• FBC: Thrombocytopenia—consider post-COVID vaccine or other hematological conditions (e.g., HIT).
• D-Dimer: Usually elevated, as in deep vein thrombosis (DVT).
• CT Scan: May be normal or show wedge-like hemorrhagic infarcts not corresponding to arterial territories. Increased contrast enhancement of falx and tentorium. Cord sign on non-contrast CT due to fresh clot along falx. Subarachnoid blood may be seen. Empty delta sign on CT with contrast identifying clot.
• CT Venography (CTV) or MR Venography (MRV): Can show empty delta sign and absence of flow in the lumen of sagittal sinus occluded by a venous clot.
• MRI and MRV: Can show the extent of infarcts, hemorrhage, and evidence of venous thrombosis.
• CSF Analysis: Raised pressure and protein. Lumbar puncture may help reduce CSF pressure. Possible rise in CSF white cell count.
• Thrombophilia Screen: Polycythemia, sickle cell anemia, deficiencies of proteins C and S, factor V Leiden mutation, antithrombin III deficiency, homocysteinemia, and the prothrombin G20210 mutation.

Prognosis Factors

• Involvement of the deep veins is associated with worse prognosis.
• Male patients may have worse outcomes.
• Right lateral sinus thrombosis is also associated with a worse prognosis.

Inherited Procoagulant Conditions

Management

• If recent COVID-19 vaccination: See specific guidelines below.
• Anticoagulation: Low Molecular Weight Heparin (LMWH) is the standard of care and may be given in a twice-daily formulation to minimize bleeding risk. Unfractionated heparin should be used in patients with renal insufficiency or those requiring rapid reversal of anticoagulation (e.g., imminent neurosurgical intervention).
• Despite alarming radiological appearances, hemorrhagic venous infarction, intracranial hemorrhage, or isolated subarachnoid hemorrhage are not contraindications for anticoagulant treatment in CVST.
• Cortical vein thrombosis is also usually treated with anticoagulation, though there are no randomized controlled trials. In a series of 116 patients, most (80%) were treated with anticoagulation, with good outcomes (6% in-hospital mortality).
• Current guidelines recommend using an oral vitamin K antagonist (usually warfarin) at standard intensity (target INR 2.5, range 2.0–3.0) for between 3 and 12 months.
• Interventional radiology with thrombolysis or clot removal has been performed in certain cases.
• Warfarin for 3-6 months followed by antiplatelets. A prolonged warfarin course (e.g., 12 months) may be considered if no cause is found.

References

• Cerebral venous thrombosis: a practical guide
• Imaging for CVST
• Cerebral Venous Thrombosis by Gregory Piazza. Circulation. 2012;125:1704–1709
• Management of CVST With Vaccine-Induced Thrombocytopenia