Brain Clot: Cerebral Venous Thrombosis — The Stroke Most Doctors Miss

When people think of a brain clot, they think of arterial occlusion causing ischemic stroke. But there is another, frequently missed form of cerebrovascular disease: cerebral venous thrombosis (CVT) — a clot forming in the venous sinuses (the brain's drainage channels). CVT disproportionately affects young women, particularly postpartum and those on oral contraceptives, and presents very differently from the classic FAST stroke symptoms.

Who Gets CVT and Why

CVT is caused by clotting within the cerebral venous sinuses, blocking blood drainage from the brain. Risk factors: pregnancy and the postpartum period (especially within the first 4 weeks after delivery — a critical window); oral contraceptive pill use (particularly combined OCP with smoking); inherited clotting disorders (Factor V Leiden, protein C/S deficiency, antiphospholipid syndrome); dehydration (common in Indian summers, particularly in young women during fever); intracranial infection (meningitis); inflammatory bowel disease.

Symptoms — Why It Is Frequently Missed

Unlike arterial stroke, CVT typically presents with: progressive severe headache (present in 80–90% of cases) — often described as the worst headache, developing over days rather than seconds; seizures (more common in CVT than arterial stroke — 40% of cases); focal weakness or speech difficulty (if the thrombosis is large); papilloedema (swelling of the optic disc from raised intracranial pressure) causing visual disturbance. The gradual onset and headache-dominant presentation causes CVT to be misdiagnosed as migraine, meningitis, or preeclampsia.

Diagnosis and Treatment

MRI with MR venography is the investigation of choice — CT scan is frequently normal or shows subtle signs only. Treatment: anticoagulation with low molecular weight heparin (even in the presence of haemorrhage — counterintuitive but evidence-based) transitioning to warfarin or DOAC for 3–12 months. Prognosis is good with early treatment — 80% of patients recover fully. Any new severe headache in a postpartum woman or young woman on OCP must be evaluated urgently. Sri Anand CNC, Chanda Nagar, Hyderabad. Call +91 90633 66983.