Strokes are brain attacks. They occur when the blood supply to the brain becomes blocked. A stroke is a medical emergency that needs immediate medical attention.
This MNT Knowledge Center article will explain why strokes occur and how they are treated, as well as exploring the different types and the steps a person can take to prevent a stroke.
Fast facts on stroke:
- During a stroke, the brain does not receive enough oxygen or nutrients, causing brain cells to die.
- Strokes need to be diagnosed and treated as quickly as possible to minimize brain damage.
- Treatment depends on the type of stroke.
- The most effective way to prevent strokes is through maintaining a healthy lifestyle and treating underlying conditions that could be a risk factor.
A stroke occurs when the supply of blood to the brain is either interrupted or reduced. When this happens, the brain does not get enough oxygen or nutrients, and brain cells start to die.
In the U.S., approximately 40 percent of people who die from stroke are male, with 60 percent of deaths occurring in females.
According to the American Heart Association (AHA), compared with Caucasian people, African-Americans have nearly twice the risk of a first-time stroke and a much higher risk of death from stroke.
As ischemic and hemorrhagic strokes have different causes, both require different forms of treatment.
It is not only important that the type of stroke is diagnosed quickly to reduce the damage done to the brain, but also because a treatment suitable for one type of stroke may be harmful when treating different type.
Ischemic strokes are caused by arteries being blocked or narrowed, and so treatment focuses on restoring an adequate flow of blood to the brain.
Treatment starts with drugs that break down clots and prevent others from forming. Aspirin can be given, as can an injection of tissue plasminogen activator (TPA). TPA is very effective at dissolving clots but needs to be injected within 4.5 hours of 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 still ongoing as to the benefit of these procedures.
There are other procedures that can be carried out to decrease the risk of strokes or TIAs. A carotid endarterectomy involves a surgeon opening the carotid artery and removing any plaque that might be blocking it.
Alternatively, an angioplasty involves a surgeon inflating a small balloon in a narrowed artery via catheter and then inserting a mesh tube called a stent into the opening. This prevents the artery from narrowing again.
Hemorrhagic strokes are caused by blood leaking into the brain, so treatment focuses on controlling the bleeding and reducing the pressure on the brain.
Treatment can begin with drugs given to reduce the pressure in the brain, control overall blood pressure, prevent seizures and prevent sudden constrictions of blood vessels.
If an individual is taking blood-thinning anticoagulants or an antiplatelet medication like warfarin or clopidogrel, they can be given drugs to counter the effects of the medication or blood transfusions to make up for blood loss.
Surgery can be used to repair any problems with blood vessels that have led or could lead to hemorrhagic strokes. Surgeons can place small clamps at the base of aneurysms or fill them with detachable coils to stop blood flow and prevent rupture.
If the hemorrhage is caused by arteriovenous malformations (AVMs), surgery can also be used to remove them if they are not too big and not too deep in the brain. AVMs are tangled connections between arteries and veins that are weaker and burst more easily than other normal blood vessels.
Strokes are life-changing events that can affect a person both physically and emotionally. After a stroke, successful recovery will often involve specific therapies and support, such as: