What is a cerebral embolism?
Cerebral embolism occurs when a wandering clot (an embolus) or some
other particle forms in a blood vessel away from the brain, usually in
the heart. The clot is carried by the bloodstream until it lodges in an
artery leading to or in the brain, blocking the flow of blood.
The most common cause of these emboli is blood clots that form during
atrial fibrillation , a disorder found in some 2-3 million Americans.
In atrial fibrillation the two small upper chambers of the heart, the
atria, quiver instead of beating effectively. Blood isn't pumped
completely out of them when the heart beats, so it pools and clots.
Stroke occurs when the blood clot enters the circulation and becomes
lodged in a narrowed artery of the brain.