Synopsis
Recognise cerebral venous sinus thrombosis across headache, seizure and focal-deficit presentations, confirm it with venous imaging, and start anticoagulation and raised-pressure management safely in specialist care.
- Cerebral venous thrombosis is an uncommon but treatable cause of headache, intracranial hypertension, seizure, focal deficit, encephalopathy or haemorrhagic venous infarction.
- Risk is increased by pregnancy and the puerperium, oestrogen-containing contraception, malignancy, inflammatory disease, infection, dehydration, inherited thrombophilia and previous venous thromboembolism.
- Headache may be progressive, thunderclap or the only symptom; papilloedema, diplopia from sixth-nerve palsy, focal seizure or a deficit crossing conventional arterial territories should raise suspicion.
- A normal non-contrast CT and a low clinical impression do not exclude CVST; obtain CT venography or MR venography when the phenotype or risk factors warrant it.
- D-dimer may support assessment in some contexts but cannot safely rule out CVST, particularly with isolated headache, limited clot burden or prolonged symptoms.
- Treat acute CVST with therapeutic heparin, usually low-molecular-weight heparin, even when the thrombosis has produced a haemorrhagic venous infarct, unless an independent contraindication exists.
- Escalate deterioration despite anticoagulation, impending herniation or severe mass effect to neurocritical, neuroradiology and neurosurgical teams for endovascular or decompressive rescue consideration.
- Search proportionately for provoking factors, plan pregnancy-safe treatment where relevant and individualise anticoagulant choice and duration after the acute phase with stroke or haematology input.
Key red flags
Declining consciousness, new pupillary abnormality or extensor posturing indicates mass effect or herniation and needs immediate neurocritical and neurosurgical action.
Rapidly worsening vision or severe papilloedema requires urgent ophthalmic and neurological pressure management to prevent permanent visual loss.
Fever with orbital, sinus, ear or mastoid infection suggests septic thrombosis requiring immediate intravenous antibiotics and ENT or surgical source control.
Pregnancy or postpartum seizure with headache and hypertension requires simultaneous assessment for CVST, eclampsia, arterial stroke and posterior reversible encephalopathy.
New deficit or seizure despite established anticoagulation may indicate thrombus propagation, worsening oedema or haemorrhage and warrants urgent repeat imaging.
Investigation priorities
Demonstrate absent filling or thrombus in dural sinuses and cortical veins rapidly alongside emergency CT.
Management branches
Headache is new or progressive with papilloedema, seizure, focal signs or a prothrombotic context.
- Assess consciousness, pupils, focal neurology, fundi, pregnancy or postpartum status, infection and VTE risk while treating seizures or instability.
- Obtain urgent CT brain plus CT venography, or MRI with MRV when clinically and logistically appropriate; do not stop at a normal unenhanced CT.
- Discuss promptly with stroke or neurology and neuroradiology if imaging is equivocal or cortical-vein thrombosis remains plausible.
- Begin therapeutic anticoagulation once diagnosed unless an independent contraindication requires an alternative specialist plan.