Cerebral venous sinus thrombosis

Cerebral venous sinus thrombosis (CVST) is the presence of a blood clot in the dural venous sinuses, which drain blood from the brain. Symptoms may include headache, abnormal vision, any of the symptoms of stroke such as weakness of the face and limbs on one side of the body, and seizures. The diagnosis is usually by computed tomography (CT scan) or magnetic resonance imaging (MRI) to demonstrate obstruction of the venous sinuses. Testing may be done to try to determine the underlying cause. Treatment is typically with anticoagulants (medication that suppresses blood clotting) such as low molecular weight heparin. Rarely thrombolysis (enzymatic destruction of the blood clot) are used. The disease may be complicated by raised intracranial pressure, which may warrant surgical intervention such as the placement of a shunt. Nine in ten people with sinus thrombosis have a headache; this tends to worsen over the period of several days, but may also develop suddenly (thunderclap headache). The headache may be the only symptom of cerebral venous sinus thrombosis. Many patients have symptoms of stroke: inability to move one or more limbs, weakness on one side of the face or difficulty speaking. This does not necessarily affect one side of the body as in the more common 'arterial' stroke. 40% of people have seizures, although it is more common in women who develop sinus thrombosis peripartum (in the period before and after giving birth). These are mostly seizures affecting only one part of the body and unilateral (occurring on one side), but occasionally the seizures are generalised and rarely they lead to status epilepticus (persistent or recurrent seizure activity for a long period of time). In the elderly, many of the aforementioned symptoms may not occur. Common symptoms in the elderly with this condition are otherwise unexplained changes in mental status and a depressed level of consciousness. The pressure around the brain may rise, causing papilledema (swelling of the optic disc) which may be experienced as visual obscurations. In severely raised intracranial pressure, the level of consciousness is decreased, the blood pressure rises, the heart rate falls and the patient assumes an abnormal posture. Cerebral venous sinus thrombosis is more common in particular situations. 85% of people have at least one of these risk factors: