Stroke occurs due to a decrease or blockage in the brain’s blood supply. A person experiencing a stroke needs immediate emergency treatment.

Stroke is a cerebrovascular disease. This means that it affects the blood vessels that feed the brain oxygen. If the brain does not receive enough oxygen, damage may start to occur.

Stroke is the fifth leading cause of death in the United States. In fact, nearly 800,000 people have a stroke each year. That equates to around one person every 40 seconds.

There are three main types of stroke:

• Ischemic stroke: This is the most common type of stroke, making up 87% of all cases. A blood clot prevents blood and oxygen from reaching an area of the brain.
• Hemorrhagic stroke:This occurs when a blood vessel ruptures. These are usually the result of aneurysms.
• Transient ischemic attack (TIA): This occurs when blood flow to a part of the brain is inadequate for a brief period of time. Normal blood flow resumes after a short amount of time, and the symptoms resolve without treatment. Some people call this a ministroke.

Stroke can be fatal. According to the American Heart Association (AHA), the age-adjusted mortality rate for 2017 was 37.6 in every 100,000 stroke diagnoses.

Treatment

Because ischemic and hemorrhagic strokes have different causes and effects on the body, both require different treatments.

Ischemic stroke

Ischemic stroke occurs due to blocked or narrowed arteries. Treatment tends to focus on restoring an adequate flow of blood to the brain.

Treatment starts with taking drugs that break down clots and prevent others from forming. A doctor may administer blood thinners such as aspirin or an injection of tissue plasminogen activator (TPA).

TPA is very effective at dissolving clots. However, the injection needs to take place within 4.5 hours of the stroke symptoms starting.

Emergency procedures include administering TPA directly into an artery in the brain or using a catheter to physically remove the clot. Research is ongoing as to the benefits of these procedures.

There are other procedures that surgeons can perform to reduce the risk of strokes or TIAs. A carotid endarterectomy, for example, involves opening the carotid artery and removing plaque that could break and travel to the brain.

Another option is angioplasty. This involves a surgeon inflating a small balloon inside a narrowed artery using a catheter. Afterward, they will insert a mesh tube, or a stent, into the opening. This prevents the artery from narrowing again.

Hemorrhagic stroke

Blood leaking into the brain can cause a hemorrhagic stroke. Treatment focuses on controlling the bleeding and reducing the pressure on the brain.

Treatment often begins with taking drugs that reduce pressure in the brain and control overall blood pressure, as well as preventing seizures and any sudden constrictions of blood vessels.

If a person is taking blood-thinning anticoagulants or antiplatelet medication, such as warfarin or clopidogrel, they can receive medications to counter the effects of the blood thinners.

Surgeons can repair some of the problems with blood vessels that have led or could lead to hemorrhagic strokes.

When an aneurysm — or a bulge in a blood vessel that may burst — causes a hemorrhagic stroke, a surgeon can place small clamps at the base of the aneurysm or fill it with detachable coils to stop the blood flow and shrink the aneurysm.