Cerebral and sinus vein thrombosis.

A blood clot in the veins that drain the blood from the brain is called a sinus or cerebral vein thrombosis. It is an uncommon type of clot, affecting about 1500 people in the United States per year. Normally, blood is transported through arteries into the brain, where it delivers oxygen and nutrients. Once the blood has done its job, it collects into small veins (known as cerebral veins) that drain into large veins, called sinus veins (Figure 1). The sinus veins lead to the jugular veins in the neck, which carry the blood back to the heart. The sinus veins have nothing in common (except for the name sinus) with the sinuses of the face on both sides of the nose and above the eyes, which can get infected, leading to sinusitis.