Know stroke, know symptoms and who is at risk
A stroke occurs when the blood supply to part of the brain is suddenly interrupted or when a blood vessel in the brain bursts, spilling blood into the spaces surrounding brain cells. In the same way that a person suffering a loss of blood flow to the heart is said to be having a heart attack, a person with a loss of blood flow to the brain or sudden bleeding inu the brain can be said to be having a “brain attack.”
Brain cells die when they no longer receive oxygen and nutrients from the blood or when they are damaged by sudden bleeding into or around the brain. Ischemia is the term used to describe the loss of oxygen and nutrients for brain cells when there is inadequate blood flow. Ischemia ultimately leads to infarction, the death of brain cells which are eventually replaced by a fluid-filled cavity (or infarct) in the injured brain.
When blood flow to the brain is interrupted, some brain cells die immediately, while others remain at risk for death. These damaged cells make up the ischemic penumbra and can linger in a compromised state for several hours. With timely treatment these cells can be saved. The ischemic penumbra is discussed in more detail in the Appendix.
Even though a stroke occurs in the unseen reaches of the brain, the symptoms of a stroke are easy to spot. They include sudden numbness or weakness, especially on one side of the body; sudden confusion or trouble speaking or understanding speech; sudden trouble seeing in one or both eyes; sudden trouble walking, dizziness, or loss of balance or coordination; or sudden severe headache with no known cause. All of the symptoms of stroke appear suddenly, and often there is more than one symptom at the same time. Therefore stroke can usually be distinguished from other causes of dizziness or headache. These symptoms may indicate that a stroke has occurred and that medical attention is needed immediately.
What are the types of stroke?
There are two types of stroke:
- Ischemic stroke is caused by a blood clot that blocks or plugs a blood vessel in the brain. This is the most common type; about 80 per cent of strokes are ischemic.
- Hemorrhagic stroke is caused by a blood vessel that breaks and bleeds into the brain
Another condition that’s similar to a stroke is a transient ischemic attack (TIA). It’s sometimes called a “mini-stroke.” TIAs happen when the blood supply to the brain is blocked for a short time. The damage to the brain cells isn’t permanent, but if you have had a TIA, you are at a much higher risk of having a stroke.
Who is at risk for a stroke?
Certain factors can raise your risk of a stroke. The major risk factors include
- High blood pressure. This is the primary risk factor for a stroke.
- Heart diseases. Atrial fibrillation and other heart diseases can cause blood clots that lead to stroke.
- Smoking. When you smoke, you damage your blood vessels and raise your blood pressure.
- A personal or family history of stroke or TIA.
- Age. Your risk of stroke increases as you get older.
- Race and ethnicity. African Americans have a higher risk of stroke.
There are also other factors that are linked to a higher risk of stroke, such as
- Alcohol and illegal drug use
- Not getting enough physical activity
- High cholesterol
- Unhealthy diet
- Having obesity
What are the symptoms of stroke?
The symptoms of stroke often happen quickly. They include
- Sudden numbness or weakness of the face, arm, or leg (especially on one side of the body)
- Sudden confusion, trouble speaking, or understanding speech
- Sudden trouble seeing in one or both eyes
- Sudden difficulty walking, dizziness, loss of balance or coordination
- Sudden severe headache with no known cause
If you think that you or someone else is having a stroke, call 911 right away.
What are the treatments for stroke?
Treatments for stroke include medicines, surgery, and rehabilitation. Which treatments you get depend on the type of stroke and the stage of treatment. The different stages are
- Acute treatment, to try to stop a stroke while it is happening
- Post-stroke rehabilitation, to overcome the disabilities caused by the stroke
- Prevention, to prevent a first stroke or, if you have already had one, prevent another stroke
Acute treatments for ischemic stroke are usually medicines:
- You may get tPA, (tissue plasminogen activator), a medicine to dissolve the blood clot. You can only get this medicine within 4 hours of when your symptoms started. The sooner you can get it, the better your chance of recovery.
- If you cannot get that medicine, you may get medicine that helps stop platelets from clumping together to form blood clots. Or you may get a blood thinner to keep existing clots from getting bigger.
- If you have carotid artery disease, you may also need a procedure to open your blocked carotid artery
Acute treatments for hemorrhagic stroke focus on stopping the bleeding. The first step is to find the cause of bleeding in the brain. The next step is to control it:
- If high blood pressure is the cause of bleeding, you may be given blood pressure medicines.
- If an aneurysm if the cause, you may need aneurysm clipping or coil embolization. These are surgeries to prevent further leaking of blood from the aneurysm. It also can help prevent the aneurysm from bursting again.
- If an arteriovenous malformation (AVM) is the cause of a stroke, you may need an AVM repair. An AVM is a tangle of faulty arteries and veins that can rupture within the brain. An AVM repair may be done through
- Injecting a substance into the blood vessels of the AVM to block blood flow
- Radiation to shrink the blood vessels of the AVM
Stroke rehabilitation can help you relearn skills you lost because of the damage. The goal is to help you become as independent as possible and to have the best possible quality of life.
Prevention of another stroke is also important, since having a stroke increases the risk of getting another one. Prevention may include heart-healthy lifestyle changes and medicines.
Can strokes be prevented?
If you have already had a stroke or are at risk of having a stroke, you can make some heart-healthy lifestyle changes to try to prevent a future stroke:
- Eating a heart-healthy diet
- Aiming for a healthy weight
- Managing stress
- Getting regular physical activity
- Quitting smoking
- Managing your blood pressure and cholesterol levels
If these changes aren’t enough, you may need medicine to control your risk factors. Courtesy:NIH: National Institute of Neurological Disorders and Stroke (US)