What is ischemic stroke?
An ischemic stroke is caused by blockage of blood vessels to or within the brain. About 85 percent of strokes are ischemic (the rest are hemorrhagic -- caused by a leaking or burst blood vessel). The loss of oxygen and nutrients caused by the blockage causes brain cells to die, resulting in temporary or permanent disability, or death.
Types of ischemic strokes
There are two types of ischemic stroke: embolic (also known as cerebral embolism) and thrombotic (aka cerebral thrombosis).
- In embolic stroke, a blood clot that has formed outside the brain, usually in the heart or a large blood vessel in the chest, travels into the brain until it lodges in and blocks a blood vessel too small for it to pass through.
- In thrombotic stroke, blockage is caused by a blood clot that forms within the brain. When a clot forms in and blocks a larger cerebral blood vessel or artery, atherosclerosis – the buildup of fatty deposits, called plaque, on the walls of the artery – is often to blame. High cholesterol causes atherosclerosis. The blockage of smaller arteries deeper in the brain has been associated with high blood pressure.
Some factors that make a person more likely to have a stroke are beyond his or her control, but other risk factors can be controlled, if not eliminated. These include:
- High blood pressure
- Heart disease
Learn more about reducing the risk of stroke »
Signs & symptoms
Treat a stroke, or even the appearance of a stroke, as a life-threatening emergency and call 911. Quick treatment is crucial to prevent brain damage. A person who is having a stroke might experience:
- Sudden numbness or weakness of face, arm or leg, especially on one side of the body.
- Sudden confusion, or trouble speaking or understanding.
- Sudden trouble seeing in one or both eyes.
- Sudden trouble walking; dizziness or loss of balance or coordination.
- Sudden severe headache with no known cause.
- Problems breathing.
- Loss of consciousness.
- Balance: Is the person having trouble walking? Loss of balance or coordination, dizziness.
- Eyes: Is the person having trouble seeing? Change in vision in one or both eyes.
- Face: Ask the person to smile. Does one side of the face droop?
- Arms: Ask the person to raise both arms. Does one arm drift downward?
- Speech: Ask the person to repeat a simple phrase. Is speech slurred or strange?
- Time: Call 911 – Stroke is frequently preventable and treatable, but you need to get help quickly.
*BE-FAST was developed by Intermountain Healthcare, as an adaptation of the FAST model implemented by the American Stroke Association. Reproduced with permission from Intermountain Healthcare. Copyright 2011, Intermountain Healthcare.
Learn more about recognizing a stroke and what to do »
Stroke patients at the Kentucky Neuroscience Institute have access to the region's top doctors and the most advanced medical technology.
A drug called a recombinant tissue plasminogen activator (or rtPA) can dissolve the clot that is causing the stroke, improve circulation to the part of the brain that’s been deprived of blood and aid recovery. The sooner the drug is administered, the more effective it will be. For most patients it must be administered within three hours of the stroke.
Also, the blood clot can be physically removed. A catheter is inserted into an artery in the groin and threaded through the vascular system into the brain. Then, a wire-mesh device pushed through the catheter can grab and remove the clot. UK HealthCare was the first health care center in the region to offer the Merci® Retrieval System, a leading-edge tool for removing potentially lethal blood clots in the brain.
Medication, physical and/or occupational therapy, speech therapy and counselling all might be involved during recovery from stroke. According to the American Stroke Association, recovery from a stroke depends on a number of factors:
- Where in the brain the stroke occurred.
- How much of the brain was affected.
- The patient’s motivation.
- Caregiver support, the quantity and quality of rehabilitation.
- How healthy the survivor was before the stroke.
The National Stroke Association says that about 795,000 Americans have a stroke each year, and that of those, at least 1 in 4 will have another stroke within their lifetime. That means managing risk factors is crucial for stroke survivors.