Stroke is the fourth leading cause of death and the leading cause of disability in the United States. When a stroke occurs, a blood vessel in the brain becomes blocked or bursts, sometimes causing permanent brain injury or even death. However, prompt treatment and follow-up care may protect brain cells and help patients lead healthy, productive lives.
There are two main types of strokes:
- Ischemic Stroke This type of stroke accounts for about 80 to 85 percent of all strokes in the United States. With ischemic stroke, the blood supply to a part of the brain becomes blocked. This prevents oxygen and nutrients from reaching brain cells. Within a few minutes, these cells may begin to die.
The underlying cause for this type of obstruction is usually atherosclerosis, a condition in which plaque or fatty deposits within the wall of the arteries in the brain and neck can lead to obstruction or narrowing. These fatty deposits can cause cerebral thrombosis or cerebral embolism. With a cerebral thrombosis, a blood clot forms within the blood vessel. Cerebral embolisms are clots that can form at another location in the circulatory system, break loose from an artery wall or from the inside lining of the heart, travel through the brain's blood vessels and can lodge in an artery in the brain.
- Hermorrhagic Stroke With hemorrhagic stroke a blood vessel within the brain leaks or ruptures and bleeds into the surrounding brain tissue. This is called an intracerebral hemorrhage. The blood can accumulate and exert pressure on the surrounding tissue. High blood pressure is a common cause of intracerebral hemorrhage. In a subarachnoid hemorrhage, blood leaks under the lining of the brain. This is often caused by a small bubble on an artery known as an aneurysm.
Risk Factors for Stroke
Risk factors for stroke that cannot be changed:
- Family History The risk of having a stroke is higher for people whose parents or siblings have had a stroke.
- Age Stroke risk increases with age — doubling every 10 years after age 55.
- Gender Before age 55, men are more likely than women to have strokes. After 55, the risk is the same for men and women. However, women are more likely than men to die of stroke.
- History of Prior Stroke, TIA or Heart Attack A person who has had a stroke in the past is at much greater risk for having another one. Risk of stroke after a TIA is greatest within the first 48 to 72 hours. Therefore, you should seek immediate medical attention for all acute neurologic changes, even if they have resolved.
- Race African Americans have higher incidence of stroke and a higher risk of death from a stroke than Caucasians do. Asian Americans have higher incidence of hemorrhagic stroke than other ethnic groups.
Risk factors for stroke that are modifiable:
- High Blood Pressure This is probably the most important modifiable risk factor for stroke. Controlling high blood pressure will greatly reduce your risk of stroke and heart attack.
- Cardiovascular Disease Congestive heart failure, a previous heart attack, a diseased aortic valve and atrial fibrillation can all raise the risk of stroke.
- Cigarette Smoking The risk of stroke is two to three times greater for smokers versus nonsmokers. The use of oral contraceptives with cigarette smoking greatly increases the risk of stroke.
- Carotid Artery Disease Fatty deposits from atherosclerosis may cause significant narrowing in the carotid arteries. This can limit blood flow to the brain as well as acts as a potential source for cerebral emboli.
- Diabetes Diabetes doubles stroke risk. Many people with diabetes also have high blood pressure, obesity and high cholesterol, which increase their stroke risk even further.
- Undesirable Blood Cholesterol Levels High blood levels of low-density lipoprotein (LDL) cholesterol and low levels of high-density lipoprotein (HDL) cholesterol increase stroke risk.
- Obesity Excess weight can double the risk of an ischemic stroke.
- Lack of Exercise and Physical Activity Both increase the risk of high blood pressure and therefore the risk for stroke. Taking the stairs, going on a brisk walk, doing some kind of activity for at least 30 minutes every day will help decrease your stroke risk.
- Use of Birth Control and Hormone Therapy Women who use birth control pills, especially if they smoke and are over age 35, have a higher risk of stroke. There is also a higher risk of stroke among women using hormone therapy for menopause.
Our Approach to Stroke
UCSF offers preventive care and screening for patients at high risk of having a stroke, as well as the latest treatments and tools for patients who have experienced one. Our neurovascular team works with patients' primary care doctors to tailor treatment plans to each person's unique case and overall health.
As a world-class stroke research program, we also apply the latest science and technology to test new treatments that might improve stroke recovery and outcomes. Interested patients may have the opportunity to participate in clinical trials.
Awards & recognition
Among the top hospitals in the nation
Best in California and No. 2 in the nation for neurology & neurosurgery
Rated high-performing hospital for stroke
Certified comprehensive stroke center
Signs & symptoms
If you are experiencing any symptoms of stroke, you should go to a doctor or hospital right away, preferably by dialing 911.
Common symptoms of stroke include:
- Sudden paralysis of a leg, arm or one side of the face
- Sudden trouble speaking or understanding speech
- Sudden vision problems, such as blurred or double vision
- Sudden loss of coordination or problems with balance
- A severe, sudden headache without apparent cause
- Sudden numbness, weakness or dizziness
Transient Ischemic Attack (TIA)
Transient ischemic attacks are sometimes called "mini-strokes." Although strokes typically occur without warning, some people may feel a temporary numbness, weakness or tingling in one arm or leg, or problems with speech, vision or balance before the actual onset of the stroke. This occurs because the blood supply to the brain is temporarily reduced, called a transient ischemic attack (TIA).
TIAs usually last a few minutes to hours and may not cause immediate permanent injury to the brain. However, a TIA is a sign that the risk of a permanent stroke is great. TIA is an emergency. Patients with TIAs should be seen right away, just like those with stroke symptoms that don't go away.
Your neurologist will perform a physical examination to determine if you've had a stroke. Your examination may include blood or urine tests, an electrocardiogram (ECG or EKG), electroencephalogram (EEG) or imaging tests.
Imaging tests may include:
- Arteriography This shows arteries in the brain that can't be seen in regular X-rays. An arteriogram may be performed if other tests don't reveal the cause of the stroke. Your doctor will make a small incision, usually in your groin, then insert a catheter, which is a flexible, thin tube, carefully through your arteries and into your carotid or vertebral artery. Your doctor will then inject a dye into the catheter that helps your cranial arteries appear more clearly in an X-ray image.
- Carotid Ultrasonography This machine sends sound waves into the tissues in your neck, which creates images on a screen. These images may reveal narrowing in the carotid arteries.
- Computed Tomography (CT) Scan With this test, X-ray beams are used to create a three-dimensional image of the brain, the brain's blood vessels and main blood flow.
- Magnetic Resonance Angiography (MRA) This procedure uses a strong magnetic field to show the arteries in the neck and brain.
- Magnetic Resonance Imaging (MRI) Using a strong magnetic field, an MRI can generate a three-dimensional image of the brain. An MRI is often used to locate an area of the brain that's been damaged by an ischemic stroke.
The neurovascular team at UCSF Medical Center, along with your primary care doctor, will design a treatment plan tailored to your medical condition, state of health and individual needs. You may need more than one kind of treatment, and you may require several visits to UCSF. You may be referred to additional doctors or other medical professionals.
It is critical to come to the hospital immediately if you experience a stroke because treatments might reduce or completely reverse the brain injury from stroke. These treatments must be given within the first few hours of stroke symptoms, so call 911 to get transportation to the Emergency Room quickly. These treatments include administration of a t-PA — a drug that opens blocked blood vessels — or devices to remove the clot from the brain using a catheter.
The next step in treating a stroke is to carefully control and monitor your blood pressure. Once your blood pressure is under control, we focus on cholesterol, smoking cessation, control of diabetes and analysis of any heart conditions you may have.
- Carotid Endarterectomy This surgery is used to remove plaque from carotid arteries to help prevent strokes. The surgeon makes an incision to open up the artery, then removes the plaque and closes the artery.
- Angioplasty and Stenting During this procedure, your surgeon places a small wire tube down a narrowed artery. A balloon attached to the tube is then inflated, which works to widen the artery. A small tube called a stent may be left within the widened artery to help keep it from closing up in the future.
Treatment for hemorrhagic stroke is designed to allow the brain to heal safely and prevent further hemorrhage. This involves using medications to reduce swelling of brain tissue. Occasionally, surgery can help remove clotted blood from around damaged brain tissue. If you have an aneurysm, it can be repaired either by open surgery or by a technique that eliminates the aneurysm from inside the vessel with the help of arteriography. UCSF Medical Center is one of the premier institutions for treating patients with cerebral aneurysms and subarachnoid hemorrhage.
UCSF Medical Center has been instrumental in the development of experimental treatments to safely remove clots in patients experiencing a stroke. For example, UCSF doctors were involved in the development of a tiny device that's placed in a catheter and threaded through an artery to reach and remove clots.
UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.