This is the most common type of stroke. An ischemic stroke happens when an artery in the brain is blocked. An ischemic stroke can be an embolic or thrombotic stroke.
Embolic Stroke: In an embolic stroke, a blood clot or plaque fragment forms, usually in the heart or the large arteries leading to the brain, and then moves through the bloodstream to the brain. In the brain, the clot blocks a blood vessel and leads to a stroke.
Thrombotic Stroke: A thrombotic stroke is a blood clot that forms inside an artery that supplies blood to the brain. The clot interrupts blood flow and causes a stroke. Two types of thrombosis can cause a stroke: large vessel thrombosis and small vessel disease (or lacunar infarction.)
Large Vessel Thrombosis: This is the most common type of thrombotic stroke. It is caused by a combination of long-term atherosclerosis (hardening of the arteries) followed by rapid blood clot formation.
Small Vessel Disease/Lacunar Infarction: Small vessel disease, or lacunar infarction, occurs when blood flow is blocked to a very small arterial vessel. Little is known about the causes of small vessel disease, but it is closely linked to hypertension (high blood pressure).