Cerebrovascular Accident (Brain Stroke) and its prevention
by MedPlus Team, March 14, 2016
“Stroke” takes place when an artery to the brain is blocked or ruptures resulting in the death of an area of brain tissue due to loss of its blood supply. Most of the strokes are ischemic (due to blockage of an artery), but some are hemorrhagic (due to rupture of an artery). In Transient ischemic attacks (TIAs) however, there is no permanent brain damage and the symptoms resolve within 1 hour.
About 80% of strokes are ischemic, usually due to a blocked artery, often blocked by a blood clot. Brain cells bereft of their blood supply fail to receive enough oxygen and glucose (a sugar), which are carried by the blood. The damage, however, depends on the duration of this deprivation of blood. If deprived for a short while, brain cells are stressed, but they can recover. If this condition is for a longer period, brain cells die, and some functions may be lost, sometimes permanently. How soon brain cells die after being deprived of blood varies.
Ministrokes or Transient ischemic attacks (TIAs) are indicators for an impending ischemic stroke. They occur due to a short interruption of the blood flow to part of the brain. In this case, however, as the blood supply is restored immediately, brain tissue does not die and the regular function returns quickly.
The remaining 20% of strokes are hemorrhagic in nature that results in bleeding in and around the brain. Here, a blood vessel ruptures, resulting in the blood leaking into brain tissue or around the brain. Brain tissue that comes into direct contact with the blood is irritated and can result in scar tissue forming in the brain, sometimes leading to seizures.
As early treatment can prevent loss of function and sensation, awareness regarding symptoms is vital. Those who exhibit any of the below symptoms should consult a doctor immediately, even if the symptoms go away:
1) Sudden weakness or paralysis on one side of the body (for example, half of the face, one arm or leg, or all of one side)
2) Sudden loss of sensation or abnormal sensations on one side of the body
3) Sudden difficulty speaking, including difficulty coming up with words and sometimes slurred speech
4) Sudden confusion, with difficulty understanding speech
5) Sudden dimness, blurring, or loss of vision, particularly in one eye
6) Sudden dizziness or loss of balance and coordination, leading to falls
One or more of the above-mentioned symptoms are present in both hemorrhagic and ischemic strokes. Symptoms of a TIA (transient ischemic attack) are also the same, but they usually disappear within an hour.
Symptoms of a hemorrhagic stroke may also include the following:
1) Sudden severe headache
2) Nausea and vomiting
3) Temporary or persistent loss of consciousness
4) Very high blood pressure
The sooner you get help, the more doctors can do to prevent complete or permanent damage to part of your brain.
Note: A stroke is a medical emergency. Anyone suspected of having a stroke should be taken immediately to a medical facility for diagnosis and treatment.
Q) How can I tell if someone else is having a stroke?
F.A.S.T test helps in identifying if a person might be having a stroke.
F is for Face drooping. Does one side of the face droop when the person tries to smile?
A is for Arm weakness. When the person raises both arms, does one arm drift downward?
S is for Speech difficulty. Can the person repeat a simple sentence (for example, “The sky is blue.”) correctly? Is his or her speech slurred?
T is for Time to call for emergency help. It’s important to get help immediately if a person has any of these symptoms.
The major risk factors for both types of stroke are:
1) Atherosclerosis (narrowing or blockage of arteries by patchy deposits of fatty material in the walls of arteries)
2) High cholesterol levels
3) High blood pressure
Atherosclerosis is a risk factor for ischemic stroke, and high blood pressure is a risk factor for hemorrhagic stroke.
Many factors can increase your risk of a stroke. Some factors can also increase your chances of having a heart attack.
Potentially treatable stroke risk factors include:
Lifestyle risk factors
1) Being overweight or obese
2) Physical inactivity
3) Heavy or binge drinking
4) Use of illicit drugs such as cocaine and methamphetamines
Medical risk factors
High blood pressure — the risk of stroke begins to increase at blood pressure readings higher than 120/80 millimeters of mercury (mm Hg). Your doctor will help you decide on a target blood pressure based on your age, whether you have diabetes, and other factors.
1) Cigarette smoking or exposure to secondhand smoke.
2) High cholesterol.
4) Obstructive sleep apnea — a sleep disorder in which the oxygen level intermittently drops during the night.
5) Cardiovascular disease, including heart failure, heart defects, heart infection or abnormal heart rhythm.
Your risk of having a stroke is higher if you:
1) Are older than 55 years
2) Have a family history of stroke
3) Are black
4) Are female
5) Have had a previous stroke or transient ischemic attack
After I have had a stroke, am I more likely to have another one?
Yes. People who have had a stroke are more likely to have another stroke. The risk is especially high during the year after your first stroke.
Strokes that affect a large part of the left side of the brain (which is responsible for language)may be particularly dangerous. Generally, the faster people improve during the days after stroke, the more they will ultimately improve.
If a hemorrhagic stroke is not very severe, and pressure within the brain is not very high, the outcome is likely to be better than that after an ischemic stroke with similar symptoms. Blood (in a hemorrhagic stroke) does not damage brain tissue as much as an inadequate supply of oxygen (in an ischemic stroke) does.
Managing risk factors
High blood pressure and diabetes should be controlled. Cholesterol levels should be monitored to prevent atherosclerosis. Smoking and use of amphetamines or cocaine should be stopped, and alcohol should be limited to no more than 2 drinks a day. Exercising regularly and, if overweight, losing weight help people control high blood pressure, diabetes, and high cholesterol levels. If you’ve already had a stroke, lowering your blood pressure can help prevent a subsequent transient ischemic attack or stroke. Having regular checkups enables a doctor to identify risk factors for stroke so that they can be managed quickly.
If you’ve had an ischemic stroke or TIA, your doctor may recommend medications to help reduce your risk of having another stroke. These include anti-platelet drugs and anticoagulants.
Prevention of strokes is preferred over treatment. Major risk factors have to be taken care of to prevent a first stroke. If one already had a stroke, additional preventive measures are required.
What is stroke rehabilitation?
Stroke rehabilitation helps build your strength, coordination, endurance, and confidence. A main goal of stroke rehabilitation is to help you learn how to live with the effects of the stroke so you can be as independent as possible. It may include physical therapy, occupational therapy, speech therapy, and swallowing therapy.
Intensive rehabilitation can help many people overcome disabilities after a stroke. The exercises and training of rehabilitation encourage unaffected areas of the brain to learn to perform functions that were done by the damaged area. Also, people are taught new ways to use muscles unaffected by the stroke to compensate for losses in function.