An ischemic stroke occurs when a blood vessel supplying blood to your brain becomes blocked or clogged. When blood flow is decreased, oxygen and necessary nutrients can’t get to your brain. In fact, brain cells and tissues begin to die within minutes.
There are two main types of ischemic strokes:
- Thrombotic strokes are caused by a blood clot (thrombus) developed in the arteries supplying blood to your brain.
When a thrombotic stroke occurs in the tiny, deep blood vessels in the brain, it is called a lacunar stroke. Lacunar strokes are most common in people who have diabetes or hypertension.
In addition to the common stroke risk factors, you should remember the following unique risk factors for thrombotic stroke:
- Age – typically occurs in older adults.
- Atherosclerosis – a buildup of fat and lipids inside blood vessel walls.
- Arteriovenous malformation (AVM) – a disorder where groups of blood vessels form incorrectly and into an unusually tangled web. AVMs are rare, but can reduce the amount of oxygen to the brain.
- Atrial fibrillation (AFib) – AFib is a kind of abnormal heart rhythm. The signal triggering the chambers of the heart to contract (beat) is disorganized. This causes the atria (the heart’s two upper cavities) to quiver or “fibrillate”. This amount of blood pumped throughout the body is inconsistent. If blood starts to pool, your risk for blood clots increases. If a blood clot occurs and travels to the brain, it may cause a stroke. The risk of developing AFib increases with age and is more common in men than in women.
- Dural arteriovenous fistulas (DAVF) – abnormal connections, usually formed during a surgery or injury, between arteries and veins near your brain. DAVF can cause blood clots to form and lead to a stroke.
- High cholesterol.
How are the signs of thrombotic stroke unique?
- Sometimes occur while sleeping
- Sometimes occur gradually over several hours or days
- You may experience one or more transient ischemic attacks (TIAs), “mini-strokes”
Ischemic strokes account for approximately 87% of all strokes.
Embolic strokes start when plaque is built up or a blood clot forms in a vessel outside of your head. An embolic stroke occurs when this clot travels through your bloodstream and reaches the blood vessels in your brain.
In addition to the common stroke risk factors, you should remember the following unique risk factors for embolic stroke:
- Having heart disease
- Undergoing heart surgery
- Having atrial fibrillation – an abnormal heart rhythm that inhibits your heart from beating effectively
- Exposure to cigarettes or alcohol during pregnancy
- Exposure to high levels of lead
- Premature birth or low birth weight
How are the signs of embolic stroke unique?
- Often occur rapidly
- Often occur without any warning signs
If you suspect you or a loved one is having a stroke get medical help immediately. Call 911.