This keeps blood from flowing to the brain. Within minutes, brain cells begin to die. Another cause is stenosis, or narrowing of the artery. A stroke is a medical emergency. Symptoms of stroke include trouble walking, speaking and understanding, as well as paralysis or numbness of the face, arm or leg. An ischemic stroke occurs when an artery in the brain becomes blocked. Ischemic stroke occurs when a vessel supplying blood to the brain is obstructed. It accounts for about 87 percent of all strokes. Ischemic stroke is one of three types of stroke. It's also referred to as brain ischemia and cerebral ischemia. This type of stroke is caused by a blockage in an artery that supplies blood to the brain. The blockage reduces the blood flow and oxygen to the brain, leading to damage or death of brain cells. There are two main causes of stroke: a blocked artery (ischemic stroke) or leaking or bursting of a blood vessel (hemorrhagic stroke). Ischemic strokes occur when blood supply is cut off to part of the brain. This type of stroke accounts for the majority of all strokes. Ischemic strokes also include something called a "mini stroke" or a TIA (transient ischemic attack).