As the first in the U.S. to receive the Joint Commission’s Comprehensive Stroke Center designation, the Stanford Health Care Stroke Center provides rapid access to every type of diagnosis and treatment for stroke or potential stroke.
Our Pleasanton center is a Stroke Center of Excellence. We extend our expertise to partner hospitals throughout Northern and Central California via our Telestroke program.
What is stroke?
A stroke occurs when blood flow to the brain stops because of a blockage or rupture in a blood vessel in the brain. A problem in the carotid artery, which carries blood to the brain, can also cause stroke.
Without blood and the oxygen it carries, brain cells start to die. The part of the body controlled by the damaged area of the brain can’t work properly.
A stroke is a medical emergency. Call 911 or go to an emergency department if you notice signs of a stroke.
Assess your stroke risk
If you're at high risk due to a previous stroke, your medical history, or your family history, we are eager to help you in the Stroke Center. Your primary care provider can guide you if you are uncertain about your risk.
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To schedule an appointment, call:
Palo Alto: 650-723-6469
Stroke symptoms often happen quickly, and brain damage can begin within minutes. Quick treatment can help limit brain damage and increase the chance of a full recovery.
For some people, stroke symptoms come on gradually. For example, you may have mild weakness at first. Over several hours, you may not be able to move the arm and leg on one side of your body.
When to call the doctor about stroke symptoms
If you or someone else has stroke symptoms, call 911 or other emergency services right away. It's important to act fast. Note the time the symptoms started—that information helps doctors provide the right care.
See your doctor if you have symptoms that seem like a stroke, even if they go away quickly. Seeing your doctor about any stroke-like symptoms can rule out other conditions and prevent brain damage from a future stroke.
Signs of a stroke often come on suddenly and may include:
- Numbness, tingling, weakness, or loss of movement in your face, arm, or leg, especially on only one side of your body
- Vision changes
- Trouble speaking
- Confusion or trouble understanding simple statements
- Problems with walking or balance
- Severe headache that is different from past headaches
BE FAST is a simple way to remember the main signs of stroke so you know when to call for medical help. FAST stands for:
- Balance suddenly changed
- Eyes affected by lost of vision
- Face drooping
- Arm weakness
- Speech difficulty
- Time to call 911
Some strokes result from arteriovenous malformations (AVMs), atypical clusters of blood vessels in the brain. AVMs may have symptoms that can lead to treatment to prevent stroke. Symptoms of AVM include:
- Progressive neurologic (thinking) problems
- Severe headaches that are unresponsive even to strong medications
Several risk factors can put you at increased risk for a stroke. Some of these risk factors are in your control, and others are not. Whatever your risk status, you can improve your odds of avoiding a stroke or having a better outcome with stroke prevention strategies and rapid treatment.
The most important risk factor for stroke is hypertension (high blood pressure). If it’s left untreated or not properly controlled, high blood pressure weakens artery walls.
High blood pressure can also promote atherosclerosis (thickening of the arterial lining). Atherosclerosis, in turn, narrows the arteries and reduces blood flow. These conditions can make it more likely that a blood clot can form, or plaque break off from a blood vessel wall, causing a blockage that leads to stroke.
Unfortunately, some risk factors come with your body. You can't change these risks:
- Age: The chance of having a stroke increases with age. Two-thirds of strokes occur in persons over age 65.
- Gender: For reasons that are not yet clear, stroke is 25% more common in men than in women.
- Race: The incidence of stroke varies among races for reasons that are probably related to genetic factors. Social factors, such as lifestyle and environment, can also play a part. African Americans have a higher incidence of hypertension and stroke than white Americans. African American people are also more likely to experience strokes at an earlier age.
- Family or personal history: A history of cerebrovascular disease in a family appears to be a contributing factor to stroke. While you have no control over your family history, you can take steps to decrease your risk through diet, exercise, and other means.
History of stroke
If you have experienced a stroke or TIA in the past, you are at increased risk for a future stroke. For you, preventive measures are particularly important. Be sure to see your doctor regularly to monitor changes that could make a stroke more likely.
Clinical trials to assess risk factors
The Stanford Health Care Stroke Center participates in clinical trials that are evaluating some recently described stroke risk factors. These risk factors may predispose some people to atherosclerosis or blood clot formation. These risks appear to be treatable.
Strokes fall into several major categories, based on whether the disrupted blood supply is caused by a blocked blood vessel or a hemorrhage. Stroke symptoms vary depending on the type, where the stroke occurs in the brain, and how bad it is.
Each type of stroke has a different type of treatment. That's why the doctor must determine the cause of the stroke and its location as quickly as possible.
The most common type of stroke is ischemic. Ischemic stroke occurs when a clot blocks a blood vessel that feeds the brain. You may also hear the term cerebral infarction in connection with ischemic stroke. An infarct is an area of necrosis (tissue death) due to the blood vessel blockage.
Ischemic strokes include:
- Thrombotic stroke (cerebral thrombosis): This is the most common type of stroke. In a thrombotic stroke, a blood clot (thrombus) forms inside an artery in the brain, blocking blood flow. Sometimes, the clot occurs in the neck arteries (carotid or vertebral artery) that transport blood from the heart to the brain. Blood clots form most often in arteries damaged by atherosclerosis, blocked or hardened arteries.
- Embolic stroke (cerebral embolism): With this type of stroke, an embolus (part of a clot) somewhere in the body breaks loose and travels to the brain. The clot plugs a blood vessel, cutting off the blood supply. This sudden blockage is called an embolism.
The other main category of stroke, hemorrhagic stroke, occurs when a blood vessel in or around the brain ruptures. These strokes are most likely to occur in people who have a combination of atherosclerosis and high blood pressure.
With a cerebral (brain) hemorrhage, the burst blood vessel spills blood into the brain or the area surrounding the brain. When a hemorrhage occurs:
- Cells normally nourished by the artery no longer get their supply of nutrients and stop working as they should.
- The accumulated blood from the ruptured artery soon clots. The clot can displace brain tissue and disrupt brain function.
- Subarachnoid hemorrhage: Bleeding occurs in the space between the brain and the skull.
- Intracerebral hemorrhage: A defective artery within the brain bursts, flooding the surrounding brain tissue with blood.
Aneurysms and AVMs
Cerebral (brain) aneurysms and arteriovenous malformations (AVMs) cause many hemorrhagic strokes. A stroke may result from:
- Burst aneurysm: An aneurysm is a bulging blood vessel in the brain. A weak spot in the vessel wall can stretch out over the years, often due to high blood pressure. If the aneurysm ruptures, blood flows into the surrounding brain tissue.
- AVM: These tangled blood vessels in the brain have a higher risk of rupturing and causing a hemorrhage.
Transient Ischemic Attack (TIA)
A transient ischemic attack (TIA) is sometimes called a mini-stroke. TIAs may last just a few minutes when a clot or other blockage temporarily decreases blood flow to your brain. Symptoms may occur only briefly during the TIA.
A TIA is a warning that a stroke may happen soon. Getting early treatment for a TIA can help prevent a stroke.
If several smaller strokes occur over time, you may have more gradual changes in walking, balance, thinking, or behavior. Doctors call these changes multi-infarct dementia.
The first test the doctor does in the emergency department is a scan of the head. This fast, noninvasive test can show any bleeding in the brain.
You may also have:
- MRI scan to provide a close look at brain tissues
- Electrocardiogram (ECG or EKG) to check for heart problems
- Blood tests to check for conditions that cause stroke-like symptoms and help your doctor make treatment recommendations
Tests you may have later
If your doctor suspects narrowing of a carotid artery, you may have:
- Carotid ultrasound or Doppler scan to evaluate blood flow through the artery
- Magnetic resonance angiogram (MRA)
- CT coronary angiogram
- Carotid angiogram
Your doctor also assesses you for risk factors for heart disease after a stroke. Many people who have a stroke also have coronary artery disease. The right care can help prevent disability or death from a future heart condition.
If your doctor believes that a problem with your heart could have caused the stroke, you may have:
- Holter monitoring
- Telemetry test, extended heart monitoring via electrodes (sticky pads) attached to your chest
Where you may have testing
We provide many tests in our emergency departments so we can deliver immediate care for stroke or possible stroke. Stanford Health Care also offers advanced diagnostic testing through our:
You can take many positive steps to reduce your risk of stroke. Lifestyle modification or medical treatment can change some risk factors for stroke. You can’t change others, such as hereditary factors. Being aware of your risk can help you take preventive action.
Because stroke is a form of cardiovascular (heart and blood vessel) disease, keeping your heart and blood vessels as healthy as possible can reduce your risk. The most important measures you can take to control your stroke risk include:
Have regular checkups
With regular checkups, your doctor can keep an eye on risk factors such as heart disease, high blood pressure, and high blood cholesterol. Your doctor can also suggest ways to control or eliminate these problems with medical care, diet, and lifestyle modifications.
Control blood pressure
High blood pressure (hypertension) is the single most important risk factor for stroke. Hypertension is often called the “silent killer” because it may not have any obvious symptoms. That’s why it’s important to check your blood pressure regularly. Even mild hypertension can increase stroke risk. In general, blood pressure should be in the 120s/80s or lower.
To reduce your stroke risk, control your blood pressure with:
- Low-sodium diet
- Medication, taken regularly according to your doctor’s instructions
- Moderate or low alcohol consumption, if you drink at all
- Regular exercise
- Stress management
- Weight control
Studies confirm that smokers have a higher risk of stroke, regardless of other factors such as age, high blood pressure, or heart disease. The risk declines dramatically within a few years of stopping smoking. Learn about our smoking cessation program.
Treat heart disease
You may be able to reduce stroke risk by treating heart conditions such as:
- Irregular heart rhythms (atrial fibrillation)
- Heart attack
- Heart valve disease
Eat a healthy diet
Foods high in fat, cholesterol, and salt increase the risk for stroke. Improve your diet by taking these steps:
- Avoid excess fat: Eating high amounts of cholesterol and fat, particularly saturated fat, may contribute to atherosclerosis, which can lead to stroke. Reduce dietary fat and cholesterol by:
- Limiting fat or oil added in cooking
- Trimming fat and skin from meats and poultry
- Using low-fat or nonfat dairy products
- Broiling and baking foods rather than frying
- Avoid excess sodium: Excess sodium in the diet is linked to hypertension. To limit sodium:
- Eat fresh foods when possible.
- Avoid oversalting foods—try non-salt seasoning instead.
- Limit processed and canned foods containing “hidden” salts such as disodium phosphate, monosodium glutamate, or sodium nitrate.
- Limit alcohol intake: People who drink more than two alcoholic beverages per day have an increased risk of stroke. For heavy drinkers, the risk of stroke increases further. Even healthy young adults who drink heavily are at higher risk of stroke.
Regular exercise minimizes body fat increase with age. Exercise can also reduce levels of atherosclerosis that can lead to stroke. Experts recommend at least 150 minutes of activity per week (20 to 30 minutes of aerobic exercise three to four times a week). Talk to your doctor before starting a new exercise program.
Diabetes can cause circulatory problems that raise stroke risk. Good control of diabetes appears to reduce the disease’s cardiovascular complications. Find out about our Diabetes Care Program.
Stress may increase blood pressure, which can indirectly raise stroke risk. A one-time stressful event rarely causes a stroke, but long-term unresolved stress can contribute to high blood pressure. Stress management techniques that can reduce blood pressure include:
- Relaxation techniques
- Psychological counseling
Reconsider oral contraceptives
Oral contraceptives (the pill) appear to increase the risk of blood clots, including clots that cause stroke. Ask your doctor about other methods of birth control if you have stroke risk factors and are currently using oral contraceptives. The risk is highest for:
- Pills with high estrogen content
- Women over age 30
- Women who smoke
Be cautious with postmenopausal estrogen use
Postmenopausal estrogen replacement (hormone replacement therapy, or HRT) can raise a woman’s risk of stroke. The risk increases the longer you take HRT. Discuss the risks with your doctor.
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Strokes—including ischemic stroke (blood clots) and hemorrhagic stroke (brain bleeds)—may cause injury or death. Our fast, expert care can reduce your risk.
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