Medicine
Cerebral Venous Sinus Thrombosis: Clinical Presentation and Management
Quick fact
Cerebral venous sinus thrombosis (CVST) accounts for less than 1% of all strokes, yet it affects young people and women more often, with over 75% of cases occurring in women of childbearing age.
Why this is interesting
You wake up with the worst headache of your life, but a CT scan of your brain looks normal. Could a small clot in a vein be the culprit?
Read the full explanation
Understanding Cerebral Venous Sinus Thrombosis: Clinical Presentation and Management
Think of the brain's venous system as a network of drainage pipes. Normally, deoxygenated blood leaves the brain through large veins called dural venous sinuses. When a clot forms in these sinuses, the drainage is blocked, leading to backward pressure. This pressure can cause fluid to leak into the brain tissue (edema), increase intracranial pressure, and even cause veins to rupture, leading to bleeding. Symptoms depend on which sinus is blocked and how quickly the blockage develops. The most common symptom is a severe headache, often described as the worst ever, which may be accompanied by blurred vision, seizures, or weakness on one side of the body. Because these symptoms are common to many other neurological conditions, CVST is notoriously difficult to diagnose.
A deeper explanation
The pathophysiology of CVST involves a cascade of events. The clot obstructs venous outflow, raising venous pressure. This impaired drainage leads to cerebral edema and increased intracranial pressure. Additionally, the backup of blood can cause venous infarction or hemorrhage, particularly if the clot extends into cortical veins. The clinical presentation is broad, ranging from isolated headache to focal deficits, seizures, or altered consciousness. Diagnosis relies on imaging such as CT venography or MR venography. Management centers on immediate anticoagulation with heparin (unfractionated or low-molecular-weight), even in the presence of hemorrhage, because the clot must be halted to prevent further thrombus extension. Seizures are treated with antiepileptic drugs if they occur. Long-term anticoagulation (e.g., warfarin or DOACs) is given for 3–12 months or longer if a prothrombotic condition is identified. Patients are also evaluated for underlying causes such as oral contraceptive use, pregnancy, infection, or inherited thrombophilias. Prognosis is generally favorable, with mortality around 5–10%, and most survivors recover fully or with minor deficits.