An ischemic stroke occurs when an artery supplying the brain with blood becomes blocked, suddenly decreasing or stopping blood flow to the brain. Eighty percent of all strokes fall into this category. The blockage is often caused by fatty deposits in the blood vessel walls. If you have these fatty deposits, which include cholesterol you have a condition called atherosclerosis. You can help prevent stroke by managing cholesterol.
Atherosclerosis can cause two kinds of blockages.
One kind of blockage is a cerebral thrombosis which is when a blood clot forms at the clogged portion of a blood vessel. It can grow large enough to block blood flow. Another kind of blockage is a cerebral embolism. This is when a blood clot forms somewhere else in the body, often the arteries of the chest and neck. A bit of the clot breaks off and moves to the brain.