Cerebrovascular Accident (Stroke)

                 Cerebrovascular Accident (CVA) or stroke is a medical emergency condition in which the brain cells suddenly die because of a lack of oxygen. A stroke can be caused by an obstruction in the blood flow, or the rupture of an artery that feeds the brain. The patient may suddenly lose the ability to speak, there may be memory problems, or one side of the body can become paralyzed.

Types

The two main types of stroke include ischemic stroke and hemorrhagic stroke.

1. Ischemic stroke :

Ischemic stroke accounts for about 87 percent of all strokes and occurs when a blood clot, or thrombus, forms that blocks blood flow to part of the brain.

If a blood clot forms somewhere in the body and breaks off to become free-floating, it is called an embolus. This wandering clot may be carried through the bloodstream to the brain where it can cause ischemic stroke.

2. Hemorrhagic stroke :

A hemorrhagic stroke occurs when a blood vessel on the brain's surface ruptures and fills the space between the brain and skull with blood (subarachnoid hemorrhage) or when a defective artery in the brain bursts and fills the surrounding tissue with blood (cerebral hemorrhage).

Both types of stroke result in a lack of blood flow to the brain and a buildup of blood that puts too much pressure on the brain.

Risk Factors

Risk factors for stroke include the following :

1. Age - as you get older your risk increases

2. Being male

3. High blood pressure

4. A family history of stroke

5. High cholesterol

6. Smoking

7. Diabetes

8. Obesity and overweight

9. A previous stroke or transient ischemic attack (TIA)

10. High levels of homocysteine (an amino acid in blood)\

11. Divorced men have a higher risk of stroke.

Signs and Symptoms

Stroke symptoms typically start suddenly, over seconds to minutes, and in most cases do not progress further. The symptoms depend on the area of the brain affected. The more extensive the area of brain affected, the more functions that are likely to be lost. Some forms of stroke can cause additional symptoms. For example, in intracranial hemorrhage, the affected area may compress other structures. Most forms of stroke are not associated with headache, apart from subarachnoid hemorrhage and cerebral venous thrombosis and occasionally intracerebral hemorrhage.

- Trouble walking, loss of balance and coordination

- Speech problems

- Dizziness

- Numbness, weakness, or paralysis

- Blurred, blackened, or double vision

- Sudden severe headache

- Confusion

Diagnosis

A stroke is a medical emergency, and anyone suspected of having one should be taken to hospital immediately so that tests can be run and the correct treatment can be provided as quickly as possible.

Physicians have several tools available to screen for stroke risk and diagnose an active stroke. These include:- Physical assessment :  blood pressure tests and blood tests to see cholesterol levels, blood sugar levels, and amino acid levels.

- Ultrasound

- Arteriography

- Computerized tomography (CT) scan

- Magnetic resonance imaging (MRI)

- CT and MRI with angiography

- Echocardiography

- Eye-movement analyzer may diagnose stroke

Treatment

The primary goal in treating ischemic stroke is to restore blood flow to the brain. This will be attempted using a blood clot-busting drug called tissue plasminogen activator (tPA). A doctor will inject tPA into the patient's arm. If for some reason the patient can't receive the tPA then an anti-platelet medicine will be used instead.

In addition, surgical procedures may be performed that can open up or widen arteries. These include carotid endarterectomy (removal of plaque and widening of the carotid artery) and angioplasty (a balloon that widens the carotid artery and is held open with a metallic mesh tube called a stent).

Hemorrhagic stroke is treated differently than ischmic stroke. Surgical methods used to treat this stroke variant include aneurysm clipping, aneurysm embolisation, and arteriovenous malformation (AVM) removal.

Aneurysm clipping consists of a small clamp placed at the base of the aneurysm that isolates it from the circulation of it's attached artery and keeps the aneurysm from bursting or re-bleeding.

Aneurysm embolisation (coiling) uses a catheter inserted into the aneurysm to deposit a tiny coil that fills the aneurysm, causing clotting and sealing off the aneurysm off from arteries. AVM removal is a surgical procedure to remove usually smaller AVMs or AMVs that are in more accessible portions of the brain in order to eliminate the risk of rupture.

Most stroke victims will require rehabilitation after the event. A person's condition is generally dependent on the area of the brain and the amount of tissue that was damaged. It is common for the rehabilitation process to include speech therapy, occupational therapy, physical therapy, and family education.

Prevention
The following Stroke Prevention Guidelines will help you learn how you may be able to lower your risk for a first stroke.

1. Know blood pressure (hypertension)
High blood pressure is a major stroke risk factor if left untreated. Have blood pressure checked yearly by a doctor or at health fairs, a local pharmacy or supermarket or with an automatic blood pressure machine.

2. Identify atrial fibrillation (Afib)
Afib is an abnormal heartbeat that can increase stroke risk by 500%. Afib can cause blood to pool in the heart and may form a clot and cause a stroke. A doctor must diagnose and treat Afib.

3. Stop smoking 
Smoking doubles the risk of stroke. It damages blood vessel walls, speeds up artery clogging, raises blood pressure and makes the heart work harder.

4. Control alcohol use 
Alcohol use has been linked to stroke in many studies. Most doctors recommend not drinking or drinking only in moderation - no more than two drinks each day.

5. Know cholesterol levels 
Cholesterol is a fatty substance in blood that is made by the body. It also comes in food. High cholesterol levels can clog arteries and cause a stroke. See a doctor if your total cholesterol level is more than 200.

6. Control diabetes
Many people with diabetes have health problems that are also stroke risk factors. A doctor and dietician can help manage diabetes.

7. Manage exercise/diet
Excess weight strains the circulatory system. Exercise five times a week. Maintain a diet low in calories, salt, saturated and trans fats and cholesterol. Eat five servings of fruits and vegetables daily.

8. Treat circulation problems 
Fatty deposits can block arteries carrying blood to the brain and lead to a stroke. Other problems such as sickle cell disease or severe anemia should be treated.

9. Transient Ischemic Attack (TIA)
A TIA is a temporary episode of stroke-like symptoms that can last a few minutes to 24 hours but usually causes no permanent damage or disability. TIA and stroke symptoms are the same. Recognizing and treating a TIA can reduce stroke risk. Up to 40 percent of people who experience a TIA may have a stroke.