Stroke

As different areas of the brain are responsible for different functions, the symptoms of stroke vary depending on which area of the brain is damaged. If you think that you or someone else may be having a stroke, some warning signs to look for are:

• Paralysis or numbness of the face, arm, or leg – especially on one side of the body
• Sudden trouble with walking, such as dizziness, loss of coordination or balance
• Trouble with speaking, such as slurring words, or difficulty understanding speech
• Difficulty seeing in one or both eyes
• Sudden, severe headache with no known cause
• Dizziness or confusion
• Sudden, severe numbness in any part of the body
• Sudden deviation of the eyes toward one direction
• Seizures
• Irregular breathing
• Coma

The sudden appearance of one or more of these symptoms is a warning sign that a stroke may be in progress. Seek immediate medical attention if you notice these symptoms. The longer a stroke goes untreated, the greater the potential for brain damage or disability.

A stroke is caused by the sudden interruption of the blood supply to the brain. There are two types of stroke: ischemic and hemorrhagic.

Ischemic stroke is by far the most common type of stroke, accounting for a large majority of strokes. It occurs as a result of an obstruction within a blood vessel supplying blood to the brain. The American Association of Neurological Surgeons divide ischemic stroke into 2 types: thrombotic and embolic. A thrombotic stroke occurs when a blood clot, called a thrombus, blocks an artery to the brain and stops blood flow. An embolic stroke is when a piece of plaque or thrombus travels from its original site and blocks an artery downstream.

Hemorrhagic stroke occurs when a weakened blood vessel ruptures. It can be caused by hypertension, or rupture of an aneurysm or vascular malformation. An intracerebral hemorrhage occurs when there is bleeding directly into the brain tissue, which often forms a clot within the brain. A subarachnoid hemorrhage occurs when the bleeding fills the cerebrospinal fluid spaces around the brain. Both conditions are very serious.

What are the risk factors?

There are many risk factors that can increase your chance of a stroke. The risk factors that can be changed or treated include:

• High blood pressure: This is one of the most significant modifiable risks. For every 10 people that die of stroke, 4 could have been saved if their blood pressure was regulated.
• Smoking: Smoking is another significant risk factor. For those under 65, two-fifths of deaths are linked to smoking.
• High cholesterol: High cholesterol can increase your chance of having a stroke.
• Diabetes: Diabetes is another risk factor associated with stroke.
• Cardiovascular disease: Cardiovascular disease including heart failure, heart defects and abnormal heart rhythm.
• Lifestyle factors: These include physical inactivity and heavy or binge drinking. The use of some birth control pills or hormone therapies that include estrogen can also increase your risk.

The following risk factors cannot be changed:

• Personal or family history of stroke, transient ischemic attack (TIA), or heart attack: The risk of stroke for someone who has already had one is many times that of a person who has not.
• Being age 55 or older: According to the American Academy of Neurology , the chance of having a stroke approximately doubles for each decade of life after age 55.

To diagnose a stroke, your doctor will first ask you questions about your symptoms and review your medical history for stroke risk factors. He or she will also conduct a physical exam to check your mental alertness and your coordination and balance. During the physical exam, your doctor may look for signs of numbness or weakness in your face, arms, and legs and assess whether you have trouble speaking and seeing clearly.

To diagnose a stroke, imaging tests will need to be conducted. Your doctor may recommend any of the following:

• Brain computed tomography (CT) scans: A CT scan, which creates cross-sectional images of the head and brain, is typically the first test after a stroke. A brain CT scan can show bleeding in the brain or damage to the brain cells from a stroke. The test also can show other brain conditions that may be causing your symptoms.
• Magnetic resonance imaging (MRI): An MRI may be used instead of, or in addition to, a CT scan to diagnose a stroke. This test uses magnetic fields to detect changes in brain tissue and damage to brain cells from a stroke.
• Magnetic Resonance Arteriogram (MRA): MRA can show the large blood vessels in the brain. This test may give your doctor more information about the site of a blood clot and the flow of blood through your brain.
• Carotid Ultrasound: Carotid ultrasound uses sound waves to create pictures of the insides of your carotid arteries, the arteries that supply oxygen-rich blood to your brain. This test shows whether plaque has narrowed or blocked your carotid arteries. Your carotid ultrasound test may include a Doppler ultrasound. Doppler ultrasound is a special test that shows the speed and direction of blood moving through your blood vessels.

If it is clear that you are having a stroke, your evaluation will include tests to check for a cause. You may have a chest x-ray and an electrocardiogram (ECG) to check for heart problems. Blood tests will evaluate your blood cell counts, liver and kidney function, and the ability of your blood to clot. These tests are done to help your doctor make choices about your treatment.

Generally there are three treatment stages for stroke: prevention, therapy immediately after the stroke (acute stroke therapy), and post-stroke rehabilitation.

Prevention

Therapies for stroke prevention treat your underlying risk factors for stroke such as high blood pressure, atrial fibrillation and diabetes. Preventative treatment is often focused on healthy lifestyle changes and taking regular medications for any conditions that can lead to a stroke. In rare cases, preventative surgery may be required. See Stroke Prevention for more details.

Acute stroke therapy

Acute stroke therapies try to stop a stroke while it is happening by quickly dissolving the blood clot causing an ischemic stroke or by stopping the bleeding of a hemorrhagic stroke.

The most effective treatment for strokes caused by a clot is a powerful clot-dissolving medication called tissue plasminogen activator (T-PA). T-PA can restore blood flow and oxygen to brain tissue affected by a stroke, but it must be given within three hours of when stroke symptoms begin. Other clot-prevention medications, such as heparin, are used in later hours after a stroke. These medicines prevent existing blood clots from getting bigger and new clots from forming. Hemorrhagic stroke on the other hand, may require surgery to remove the hemorrhaged blood and relieve pressure on the brain.

Post-stroke rehabilitation

Post-stroke rehabilitation helps individuals overcome disabilities that result from stroke damage. A person who has experienced a significant stroke of any type usually is hospitalized for observation in case the symptoms worsen. Hospitalization is often followed by a period of residence at a rehabilitation center. There, additional therapy may be provided intensively. The goal of rehabilitation is to maximize recovery.

People who have had a stroke may need help with self-care or feeding. Early intervention by an occupational therapist and physical therapist is helpful. These therapists can help a person work around a new disability and regain strength after brain injury.

Knowing your stroke risk factors and adopting a healthy lifestyle are the best steps you can take to prevent a stroke. Some tips are:

• Control high blood pressure (hypertension) and/or manage atrial fibrillation: These conditions are both risk factors for a stroke. Managing and controlling them with prescribed medications, such as anticoagulants and antihypertensives, can help to prevent a stroke.
• Eat a healthy diet: Improve your diet by eating more fruits and vegetables, especially potassium-rich foods like bananas and oranges. Increase your intake of whole grains and lower the amount of cholesterol, saturated fat and salt in your diet.
• Maintain a healthy weight: Maintain a healthy weight by balancing the calories you eat with physical activity.
• Stay physically active: Exercise regularly, even if you don't need to lose weight. Exercise reduces your risk of a stroke in many ways, including lowering your blood pressure, controlling diabetes and reducing your stress.
• Limit your alcohol intake: Excessive consumption of alcohol increases your chance of having a stroke. Limit alcohol to 1 to 2 drinks per day.
• Quit smoking: Smoking can damage and tighten blood vessels and raise your risk of stroke. Talk with your doctor about programs and products that can help you quit. In addition, avoid secondhand smoke where possible as secondhand smoke can also damage the blood vessels.
• Daily aspirin: Talk to your doctor about the potential benefits of taking an aspirin daily. Aspirin, in doses as low as 80 milligrams per day, can reduce the risk of stroke by minimising the risk of blood clots. However, consult with your doctor first as aspirin is not safe for everyone.
• Preventative medical procedures: In some cases, medical procedures may be required to reduce your risk of a stroke. This may include a carotid endarectomy, a procedure in which blood vessel blocked by fatty plaque is surgically removed from the carotid artery. Doctors may also use balloon angioplasty and implantable steel screens called stents to treat cardiovascular disease and help open up the blocked blood vessel.