Stroke

Cause

Causes of ischemic stroke

An ischemic stroke is caused by a blood clot that blocks blood flow to the brain.

• A blood clot can form in an artery that supplies blood to the brain.
  • Blood clots usually form in arteries damaged by plaque buildup, which is a process called atherosclerosis.
  • Long-term high blood pressure or diabetes may damage smaller blood vessels in the brain, causing a clot to form within the blood vessels and block blood flow.
• A blood clot can form in another part of the body (often the heart) and travel through the bloodstream to the brain. For example, clots may form:
  • After a heart attack.
  • As a result of other problems that change the blood flow through the heart. These conditions include abnormal heart rhythms (especially atrial fibrillation), heart valve problems, patent foramen ovale, atrial septal defects, and heart failure.

Low blood pressure may also cause an ischemic stroke, although this is less common. Low blood pressure results in reduced blood flow to the brain. It may be caused by narrowed or diseased arteries, a heart attack, a large loss of blood, or a severe infection.

Some surgeries (such as endarterectomy) or other procedures (such as carotid artery stenting) that are used to treat narrowed carotid arteries may cause a blood clot to break loose, resulting in a stroke.

Causes of hemorrhagic stroke

A hemorrhagic stroke is caused by bleeding in or around the brain.

• Bleeding inside the brain itself (intracerebral hemorrhage, or ICH) may be a result of long-term high blood pressure or use of blood thinner medicine, such as anticoagulants.
• Bleeding in the space around the brain (subarachnoid hemorrhage, or SAH) may be caused by a ruptured aneurysm or uncontrolled high blood pressure.

Other less common causes include head or neck injuries, certain diseases, and radiation treatment for cancer in the neck or brain.

Symptoms

If you have symptoms of a stroke, call 911 or other emergency services right away. General symptoms of a stroke include:

• Sudden numbness, tingling, weakness, or loss of movement in your face, arm, or leg, especially on only one side of your body.
• Sudden vision changes.
• Sudden trouble speaking.
• Sudden confusion or trouble understanding simple statements.
• Sudden problems with walking or balance.
• A sudden, severe headache that is different from past headaches.

FAST is a simple way to remember the main symptoms of stroke. Recognizing these symptoms helps you know when to call for medical help. FAST stands for:

• F ace drooping.
• A rm weakness.
• S peech difficulty.
• T ime to call 911.

Symptoms can vary depending on whether the stroke is caused by a blood clot (ischemic stroke) or bleeding (hemorrhagic stroke), where the stroke occurs in the brain, and how bad it is.

A stroke usually happens suddenly but may occur over hours. For example, you may have mild weakness at first. Over time, you may not be able to move the arm and leg on one side of your body.

If several smaller strokes occur over time, you may have a more gradual change in walking, balance, thinking, or behavior. This is called multi-infarct dementia.

It isn't always easy for people to recognize symptoms of a small stroke. They may mistakenly think the symptoms can be attributed to aging. Or the symptoms may be confused with those of other conditions that cause similar symptoms.

What Happens

When you have an ischemic stroke, the oxygen-rich blood supply to part of your brain is reduced. With a hemorrhagic stroke, there is bleeding in the brain.

After about 4 minutes without blood and oxygen, brain cells become damaged and may die. The body tries to restore blood and oxygen to the cells by enlarging other blood vessels (arteries) near the area.

If blood supply isn't restored, permanent damage usually occurs. The body parts controlled by those damaged cells cannot function.

This loss of function may be mild or severe. It may be temporary or permanent. It depends on where and how much of the brain is damaged and how fast the blood supply can be returned to the affected cells. Life-threatening complications may also occur. This is why it's important to get treatment as soon as possible.

Recovery

Recovery depends on the location and amount of brain damage caused by the stroke, the ability of other healthy areas of the brain to take over for the damaged areas, and rehabilitation. In general, the less damage there is to the brain tissue, the less disability results and the greater the chances of a successful recovery.

Stroke is the most common nervous-system–related cause of physical disability. Of people who survive a stroke, half will still have some disability 6 months after the stroke.

You have the greatest chance of regaining your abilities during the first few months after a stroke. Regaining some abilities, such as speech, comes slowly, if at all. About half of all people who have a stroke will have some long-term problems with talking, understanding, and decision-making. They also may have changes in behavior that affect their relationships with family and friends.

After a stroke, you (or a caregiver) may also notice:

• Changes in speed of action.
• Changes in judgment.
• Changes in emotions.
• Changes in perception (the ability to judge distance, size, position, rate of movement, form, and how parts relate to the whole).
• Memory problems.
• Problems from neglecting the affected side of the body.

Long-term problems

Long-term complications of a stroke, such as depression and pneumonia, may develop right away or months to years after a stroke.

Some long-term problems may be prevented with proper home treatment and medical follow-up. For more information, see Home Treatment.

What Increases Your Risk

A risk factor is anything that makes you more likely to have a particular health problem. Risk factors for stroke that you can treat or change include:

• High blood pressure (hypertension).
• Atrial fibrillation.
• Diabetes.
• Smoking.
• High cholesterol.
• Heavy use of alcohol.
• Being overweight.
• Physical inactivity.

Risk factors you cannot change include:

• Age. The risk of stroke increases with age.
• Race. African Americans, Native Americans, and Alaskan Natives have a higher risk than those of other races.
• Gender. Women have a higher risk of having a stroke compared to men. In people ages 55 to 75, about 2 out of 10 women will have a stroke and 1 or 2 out of 10 men will have a stroke.
• Family history. The risk for stroke is greater if a parent, brother, or sister has had a stroke or transient ischemic attack (TIA).
• History of stroke or TIA.

When To Call

Call 911 or other emergency services immediately if you have signs of a stroke:

• Sudden numbness, tingling, weakness, or loss of movement in your face, arm, or leg, especially on only one side of your body.
• Sudden vision changes.
• Sudden trouble speaking.
• Sudden confusion or trouble understanding simple statements.
• Sudden problems with walking or balance.
• A sudden, severe headache that is different from past headaches.

Signs of a transient ischemic attack (TIA) are similar to signs of a stroke. But TIA symptoms usually disappear after 10 to 20 minutes, although they may last longer. There is no way to tell whether the symptoms are caused by a stroke or by TIA, so emergency medical care is needed for both conditions.

Call your doctor now if you:

• Have had recent symptoms of a TIA or stroke, even if the symptoms have disappeared.
• Are taking aspirin or other medicines that prevent blood clotting and you notice any signs of bleeding.
• Have a choking episode from food going down your windpipe.
• Have signs of a blood clot in a deep blood vessel. These include redness, warmth, and pain in a specific area of your arm or leg.

Call your doctor for an appointment if you:

• Think you have had a TIA in the past and have not talked with your doctor about it.
• Have a pressure injury.
• Notice that your affected arm or leg is getting stiffer or you can't straighten it (spasticity).
• Notice signs of a urinary tract infection. Signs may include fever, pain with urination, blood in urine, and low back (flank) pain.
• Are having trouble keeping your balance.

Exams and Tests

Tests in the emergency room

The first test after a stroke is typically a CT scan, a series of X-rays that can show whether there is bleeding in the brain. This test will show whether the stroke is ischemic or hemorrhagic. You may also have an MRI.

Other initial tests recommended for ischemic stroke include:

• Electrocardiogram (ECG, EKG) to check for heart problems.
• Blood tests to help your doctor make choices about your treatment and to check for conditions that may cause symptoms similar to a stroke. Tests may include:
  • Complete blood count (CBC).
  • Blood sugar.
  • Electrolytes.
  • Liver and kidney function.
  • Prothrombin time and INR (a test that measures how long it takes your blood to clot).

Tests you may have later

If it seems that you may have a narrowing of a carotid artery, your doctor may want you to have a:

• Carotid ultrasound/Doppler scan to evaluate blood flow through the artery.
• Magnetic resonance angiogram (MRA).
• CT angiogram.
• Carotid angiogram.

If your doctor believes that the stroke may have been caused by a problem with your heart, an echocardiogram or Holter monitoring or telemetry test may be done.

Guidelines recommend that risk factors for heart disease also be assessed after a stroke to prevent disability or death from a future heart problem. This is because many people who have had a stroke also have coronary artery disease.

Treatment Overview

Emergency treatment

Ischemic stroke

Measures will be taken to stabilize your vital signs, including giving you medicines.

• You may be given a clot-dissolving medicine called tissue plasminogen activator (TPA). This medicine can improve recovery from a stroke, especially if given as soon as possible after the stroke happens. Doctors try to give this medicine within 3 hours after symptoms start. Some people may be helped if they are able to get this medicine within 4½ hours of their first symptoms.^{footnote 3}
• You may also receive aspirin or another antiplatelet medicine.
• In some cases, a procedure may be done to restore blood flow. The doctor uses a thin, flexible tube (catheter) and a tiny cage to remove the blood clot that caused the stroke. This procedure is called a thrombectomy.

Hemorrhagic stroke

Treatment includes efforts to control bleeding, reduce pressure in the brain, and stabilize vital signs, especially blood pressure.

• To stop the bleeding, you may be given medicine or a transfusion of parts of blood, such as plasma. These are given through an IV.
• You will be closely monitored for signs of increased pressure on the brain. These signs include restlessness, confusion, trouble following commands, and headache. Other measures will be taken to keep you from straining from excessive coughing, vomiting, or lifting, or straining to pass stool or change position.
• If the bleeding is due to a ruptured brain aneurysm, surgery to repair the aneurysm may be done. For more information, see Surgery.
• In some cases, medicines may be given to control blood pressure, brain swelling, blood sugar levels, fever, and seizures.
• If a large amount of bleeding has occurred and symptoms are quickly getting worse, you may need surgery to remove the blood that has built up inside the brain and to lower pressure inside the head.

Preventing another stroke

Your treatment will also focus on preventing another stroke. This may include:

• Reducing high blood pressure, the most common risk factor for stroke, by making changes to your diet and taking medicines that lower blood pressure.
• Taking aspirin or another antiplatelet medicine to prevent strokes. For more information, see Medications.
• Controlling diabetes. Your doctor will advise you to try to keep your blood sugar levels in a target range. To do this, you may need to take insulin or other diabetes medicine. A healthy diet and plenty of exercise will also help.
• Getting a flu shot every year to help you avoid getting sick from the flu.

You may also need to make lifestyle changes such as quitting smoking, eating heart-healthy foods, and being active. For more information, see Prevention.

If your carotid arteries are significantly blocked, you may need a procedure to reopen the narrowed arteries. For more information, see Surgery and Other Treatment.

Tips for a successful recovery

• Be as involved as possible in your care . You may feel like letting a caregiver take charge. But the more you can participate, the better.
• Recognize symptoms of depression and ask for help . Symptoms include feeling sad or hopeless all the time, or losing interest in activities that used to make you happy. Depression is common in people who have had a stroke. The sooner you know if you are depressed, the sooner you can get treatment. Treatment can help you feel better.
• Get into a stroke rehabilitation (rehab) program as soon as possible.

Rehab

Starting a rehab program as soon as possible after a stroke increases your chances of regaining some of the abilities you lost.

Your rehab will be based on the physical abilities that were lost, your general health before the stroke, and your ability to participate. Rehab begins with helping you resume activities of daily living, such as eating, bathing, and dressing. Rehab can also help you make changes in your lifestyle, at home, at work, and in relationships. The changes you make will depend on how the stroke affected you.

Rehab can help you to:

• Do as well as you can and be as independent as possible.
• Learn to live with the changes to your brain and body caused by the stroke.
• Adjust to living within your home, family, and community.

If you are someone whose loved one has had a stroke, you can play an important role in that person's recovery by providing support and encouragement.

It's not possible to predict how much ability you will regain. The more ability you retain immediately after a stroke, the more independent you are likely to be when you are discharged from the hospital. For more information, see the topic Stroke Rehabilitation.

Long-term care

Some people move to a care facility that can meet their needs. There are several kinds of long-term care. Each provides different levels of care, assistance, and services. The quality and costs of care and services at long-term care facilities vary widely, and options vary from one community to another. Your doctor or rehab team can help you find which type of long-term care would be best for you.

• Stroke: Should I Move My Loved One Into Long-Term Care?

Palliative care

Palliative care is a kind of care for people who have a serious illness. It's different from care to cure your illness. Its goal is to improve your quality of life—not just in your body but also in your mind and spirit.

You can have this care along with treatment to cure your illness. You can also have it if treatment to cure your illness no longer seems like a good choice.

Palliative care providers will work to help control pain or side effects. They may help you decide what treatment you want or don't want. And they can help your loved ones understand how to support you.

If you're interested in palliative care, talk to your doctor.

End-of-life care

A time may come when treatment for your illness no longer seems like a good choice. This can be because the side effects, time, and costs of treatment are greater than the promise of cure or relief. But you can still get treatment to make you as comfortable as possible during the time you have left. You and your doctor can decide when you may be ready for hospice care.

For more information, see the topics:

• Hospice Care
• Care at the End of Life

Prevention

You can help prevent a stroke if you control risk factors and treat other medical conditions that can lead to a stroke. You can help prevent a TIA or stroke by taking steps toward a heart-healthy lifestyle.

Know your stroke risk

Your doctor can help you know your risk. These are some of the common risk factors for stroke:

• You have atrial fibrillation.
• You smoke.
• You have high blood pressure.
• You have high cholesterol.
• You have diabetes.
• You are overweight.
• You do not exercise on a regular basis.
• You drink large amounts of alcohol.

Treat any health problems you have

• Manage high blood pressure or high cholesterol by working with your doctor.
• Manage diabetes. Keep your blood sugar levels within a target range.
• If your doctor recommends that you take aspirin or a blood thinner, take it.
• Take your medicine exactly as prescribed. Call your doctor if you think you are having a problem with your medicine.

Adopt a healthy lifestyle

• Don't smoke or allow others to smoke around you. For more information, see the topic Quitting Smoking.
• Limit alcohol to 2 drinks a day for men and 1 drink a day for women.
• Stay at a healthy weight. Being overweight makes it more likely you will develop high blood pressure, heart problems, and diabetes. These conditions make a stroke more likely.
• Try to do at least 2½ hours a week of moderate exercise. One way to do this is to be active 30 minutes a day, at least 5 days a week. Or try to do vigorous activity at least 1¼ hours a week.
• Eat heart-healthy foods. These include fruits, vegetables, high-fiber foods, and foods that are low in sodium, saturated fat, and trans fat. Eat fish at least 2 times each week. Oily fish, which contain omega-3 fatty acids, are best. These fish include salmon, mackerel, lake trout, herring, and sardines.

Self-Care

Tips for dealing with the effects of a stroke

• Use a cane or a walker to help prevent falls.
• Manage getting dressed . Talk with an occupational therapist about devices—such as reachers, sock aids, and buttonhooks—that can help you get dressed.
• Manage vision problems. After a stroke, some people have problems seeing to one side. For example, people with right-sided paralysis may have difficulty seeing to the right.
• Don't neglect your affected side . It's natural to favor the side of your body that wasn't affected by stroke. But it's important to pay attention to the rest of your body too.
• Manage eating problems. You may not be able to feel food on one or both sides of your mouth. This increases your risk for choking. You may need further tests or an evaluation by a speech therapist.
  • Stroke Recovery: Coping With Eating Problems
• Manage bladder problems , such as emptying your bladder regularly. Some people suffer loss of bladder control after a stroke. But this is usually temporary.

Tips for family members and caregivers

• Provide support and encouragement . Strong support from the family can be a big help in stroke recovery.
• Help with speech problems. Your loved one may have trouble communicating, which can be very frustrating. You can help by speaking slowly and directly and listening carefully.

Medicines

Your doctor will probably prescribe several medicines after you have had a stroke. Medicines to prevent blood clots are typically used, because blood clots can cause TIAs and strokes.

The types of medicines that prevent clotting are:

• Anticoagulant medicines.
• Antiplatelet medicines.

Cholesterol-lowering and blood-pressure–lowering medicines are also used to prevent TIAs and strokes.

Anticoagulant medicines

Anticoagulants prevent blood clots from forming and keep existing blood clots from getting bigger.

You may need to take this type of medicine after a stroke if you have atrial fibrillation or another condition that makes you more likely to have another stroke. For more information, see the topic Atrial Fibrillation.

Antiplatelet medicines

Antiplatelet medicines keep platelets in the blood from sticking together.

These medicines include:

• Aspirin (for example, Bayer).
• Aspirin combined with dipyridamole (Aggrenox).
• Other antiplatelet medicines, such as clopidogrel (Plavix).

Cholesterol medicines

Statins and other medicines, such as ezetimibe, lower cholesterol and your risk for another stroke.

Blood pressure medicines

If you have high blood pressure, your doctor may want you to take medicines to lower it. Blood pressure medicines include:

• Angiotensin II receptor blockers (ARBs).
• Angiotensin-converting enzyme (ACE) inhibitors.
• Beta-blockers.
• Calcium channel blockers.
• Diuretics.

Other medicines

Medicines used to treat depression and pain may also be prescribed after a stroke.

Surgery

When surgery is being considered after a stroke, your age, prior overall health, and current condition are major factors in the decision.

Surgery for ischemic stroke

If you have serious blockage in the carotid arteries in your neck, you may need a carotid endarterectomy. During this surgery, a surgeon removes plaque buildup in the carotid arteries. The benefits and risks of this surgery must be carefully weighed, because the surgery itself may cause a stroke.

• Stroke Prevention: Should I Have a Carotid Artery Procedure?

Surgery for hemorrhagic stroke

Treatment for hemorrhagic stroke may include surgery to:

• Drain or remove blood that is in or around the brain.
• Repair a brain aneurysm.
  • In an endovascular embolization, soft metal coils or mesh is inserted into the aneurysm to block it off and stop or prevent bleeding.
  • In a craniotomy, a small metal clip is placed around the base of the aneurysm to block it off. This stops the bleeding in the brain.
• Remove or block off abnormally formed blood vessels (arteriovenous malformation) that have caused bleeding in the brain.

Other Treatment

Carotid artery stenting

Carotid artery stenting (also called carotid angioplasty and stenting) is sometimes done as an alternative to surgery to prevent stroke.

In this procedure, a doctor threads a thin tube called a catheter through an artery in the groin and up to the carotid artery in your neck. The doctor then uses a tiny balloon to enlarge the narrowed portion of the artery and places a stent to keep the artery open.

• Stroke Prevention: Should I Have a Carotid Artery Procedure?

Carotid artery stenting is not as common as carotid endarterectomy, a type of surgery.

Thrombectomy

Thrombectomy is a procedure to remove a blood clot from a blood vessel. It can be used for some people who have had a stroke that was caused by a blood clot.

Thrombectomy can remove the clot and help blood to flow normally again. This can help limit damage to the brain.

In this procedure, the doctor puts a thin, flexible tube (catheter) into a blood vessel in the groin. The doctor moves the catheter through the blood vessel into the brain. The catheter is used to remove the clot. This is done with a tiny tool that looks like a wire cage. It fits inside the catheter.