Cerebral venous sinus thrombosis

Cerebral venous sinus thrombosis (CVST), cerebral venous and sinus thrombosis or cerebral venous thrombosis (CVT), is the presence of a blood clot in the dural venous sinuses (which drain blood from the brain), the cerebral veins, or both. Symptoms may include severe headache, visual symptoms, any of the symptoms of stroke such as weakness of the face and limbs on one side of the body, and seizures, which occur in around 40% of patients. The diagnosis is usually by computed tomography (CT scan) or magnetic resonance imaging (MRI) to demonstrate obstruction of the venous sinuses. After confirmation of the diagnosis, investigations may be performed to determine the underlying cause, especially if one is not readily apparent. Treatment is typically with anticoagulants (medications that suppress blood clotting) such as low molecular weight heparin. Rarely, thrombolysis (enzymatic destruction of the blood clot) or mechanical thrombectomy is used, although evidence for this therapy is limited. 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 cerebral venous 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. Many have symptoms of stroke: inability to move one or more limbs, weakness on one side of the face or difficulty speaking. The neurologic deficits related to central venous thromboses does not necessarily affect one side of the body or one arterial or brain territory as is more common "arterial" strokes. Bilateral 6th cranial nerve palsies may occur, causing abnormalities related to eye movement, but this is rare. 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).