What is a stroke?
Stroke is an attack on the brain, affecting the arteries leading to and within the brain. A stroke occurs when a blood vessel that carries oxygen and nutrients to the brain is either blocked by a clot or ruptures. When that happens, part of the brain cannot get the blood and oxygen it needs so that part of the brain and brain cells die. This can lead to permanent damage and changes in speech, mobility and memory.
Who is at risk of a stroke?
Stroke can occur in anyone though certain factors put people more at risk, including having:
People who drink alcohol and those who smoke are also more at risk for stroke at some point in their lives. The condition is also more common in women and in the African American population.
Types of strokes
There are two types of stroke:
- Ischemic – The more common of the two types, this is when a blood vessel gets blocked, cutting off flow to the brain.
- Hemorrhagic – This is less common but can be deadly, caused by a brain aneurysm or a leaking blood vessel.
While less common than strokes caused by a blood clot, hemorrhagic strokes cause death more often than ischemic strokes. A hemorrhagic stroke occurs when a weakened blood vessel, either an aneurysm or an arteriovenous malformation (AVM), ruptures and bleeds into the brain. The leaked blood puts too much pressure on brain cells, which damages them. Hemorrhagic strokes that are caused by bleeding cannot be treated with tPA (tissue plasminogen activator, a medication that helps break up blood clots) because the medication can cause more bleeding. Instead, this type of stroke is treated with other neurointerventional procedures such as endovascular coiling.