Stroke

The two main types of stroke are termed ischemic and hemorrhagic and involve blood vessels in the brain. Ischemic strokes comprise about 80% to 85% of all strokes and are caused when a blood vessel in the brain becomes clogged with a clot just like the clogged arteries in the heart. A hemorrhagic stroke is caused when a blood vessel in the brain actually bursts or leaks. Hemorrhagic strokes tend to be more serious. The distinction between these two types of stroke can be critical in determining the treatment used to help the patient. The "third" stroke type, considered by some investigators to be a subtype of ischemic strokes, is a TIA or transient ischemic attack (also termed mini-stroke).

• Ischemic strokes occur when a blood vessel gets so narrow or clogged that not enough blood can get through to supply oxygen and keep the brain cells alive.
  • Plaques (or buildup of cholesterol-containing fatty deposits called arteriosclerosis) in the blood vessel walls can narrow the blood vessels that supply the brain. These plaques build up until the center of the blood vessel is so narrow that little, if any, blood can get past. Many things including high cholesterol and high blood pressure cause plaques. The plaques may occur in small vessels that supply only a very tiny portion of the brain but may also occur in the big blood vessels in the neck (carotids) or in the large arteries to the brain (cerebral arteries).
  • Ischemic strokes may also be caused by small blood clots or emboli that go through the bloodstream and then get clogged in an artery when the artery narrows. These clots can come from pieces of plaques in the bigger arteries that break off or from clots in the heart.
  • Treatment is designed to break up or get rid of the blockage (see treatment section below).
• Hemorrhagic strokes occur when the wall of a blood vessel becomes weak and blood leaks out into the brain.
  • In addition to having decreased blood flow past the leak, the blood in the brain damages brain cells as it decomposes. If a lot of blood leaks out, it can cause a buildup of pressure in the brain because the brain is enclosed in the skull. There is no room for brain tissue to expand, and so the leaked blood can compress and kill important areas of the brain.
  • Hemorrhagic strokes tend to be more serious than ischemic strokes. Death occurs in 30% to 50% of people with this type of stroke.
  • Treatment is designed to stop or prevent bleeding into brain tissue (see treatment section below).

Treating a hemorrhagic stroke with treatment designed for an ischemic stroke will likely cause worsening of the stroke or death.

The symptoms of a stroke depend on what part of the brain and how much of the brain tissue is affected.

• Stroke symptoms usually come on suddenly -- in minutes to an hour.
• There is usually no pain associated with the symptoms.
• The symptoms may come and go, go away totally, or get worse over the course of several hours.
• If the symptoms go away completely in a short time (fewer than 24 hours), the episode is called a transient ischemic attack (TIA).
• One-third of all strokes occur during sleep, so people first notice the symptoms when they wake up; this situation makes it difficult to time when the stroke actually began.

Eight common symptoms of stroke are:

1. Weakness in the arm, leg or both on the same side: This can range from total paralysis to a very mild weakness. Complete numbness or a pins-and-needles feeling may be present on one side of the body or part of one side of the body.
2. Weakness in the muscles of the face: The face may droop or look lopsided. Speech may be slurred because the patient can't control the movement of the lips or tongue.
3. Difficulty speaking: The patient can't speak, speech may be very slurred, or when the person speaks, the words sound fine but do not make sense.
4. Coordination problems: The patient may seem uncoordinated, stumble, have difficulty walking, or have difficulty picking up objects.
5. Dizziness: The patient may feel drunk or dizzy or have difficulty swallowing.
6. Vision problems: The patient may develop difficulty with vision, such as double vision, loss of peripheral (side) vision, or blindness. (Blurred vision by itself is not usually a symptom of stroke.)
7. Sudden headache: A sudden, severe headache may strike like "a bolt out of the blue."
8. Loss of consciousness: The patient may become unconscious or hard to arouse and could die.

Stroke is a medical emergency. If you think you are having a stroke or a person with you is having a stroke, immediately call 9-1-1 for an ambulance and transport to a hospital's emergency department; do not delay in making the call to 9-1-1.

The doctor takes a medical history of the person who may have had a stroke and performs a physical examination, which includes checking blood pressure and pulse, heart and lungs, as well as a neurologic examination. The doctor may be able to tell what is going on simply from the examination.

Most of the time, however, laboratory tests and X-rays are ordered. These may be directed at ruling out other causes of the problem (such as infection or very low blood sugar) or testing for the stroke directly. These are important tests as they help determine the best treatment to be offered to help the patient and can help distinguish between a stroke type and other treatable causes that can produce stroke-like symptoms.

• Laboratory tests: The doctor orders blood work to measure blood sugar, kidney function, salt balance, white blood cell count (sign of infection), hematocrit (looking for anemia), and other appropriate tests. There is no specific blood test available yet to detect stroke.
• CT scans: The most important imaging study at this time for stroke is a CT scan of the head. This study produces a 3-dimensional picture of the brain. In areas where there is an ischemic stroke, the brain may appear abnormal. Signs of swelling may also be present. Most strokes, even big ones, do not show up on the CT scan until 12 to 24 hours after the onset of symptoms. Small strokes may not be visible at all. CT scans are, however, good at detecting bleeding in the brain. A CT scan can help rule out a hemorrhagic stroke.
• MRI: Magnetic resonance imaging (MRI) provides a more detailed and sensitive picture of the brain, and frequently is used after the acute emergency or if the original CT scan is inconclusive.
• X-rays: The doctor may order a chest X-ray to make sure there is nothing wrong with the patient's lungs (such as cancer or pneumonia) that might be causing the symptoms.
• Other common tests: Common tests that are ordered include an electrocardiogram (ECG, EKG) to look for heart disease and irregularities, and a urinalysis to look for kidney abnormalities and infection. A doctor may evaluate the patient's mental status and abilities by asking simple but very specific questions ("What day is it?" or "Who is the President of the United States?").

The emergency department doctor often consults a neurologist or member of a stroke team to help decide what treatment is best. Sometimes, because of the wide variety of symptoms that a stroke can present and the lack of a single specific test for stroke, making this decision about treatment can be difficult.

Treatment for stroke involves emergent care to minimize brain damage and preserve brain function.

Stroke is a medical emergency and seconds count. Brain cells begin to die within 4 minutes of the beginning of a stroke. Call 9-1-1 for emergency medical transport to a hospital's emergency department. If a person is having stroke-like symptoms, do not attempt self-care.

• The American Heart Association/American Stroke Association guidelines recommend taking the patient via EMS ambulance to the nearest hospital that is designated as a stroke center. Designated stroke centers have met criteria (for example, they have neurologists and neurosurgeons on call or present, and rapid availability of CT scans) that allow more optimal treatment of patients with strokes. Ideally, the hospital should be notified by EMS that a stroke patient is in transit so the hospital staff can be in the emergency department quickly and tests like a head CT scan will not be delayed.
• Current treatments for acute stroke must be given by a doctor and within a short time of the onset of symptoms. It is crucial for the person experiencing a stroke to get to the emergency department (preferably in a stroke center designated hospital) as quickly as possible to get the most benefit from any treatment.
• If you think you are having a stroke or someone with you is having a stroke, call 9-1-1.
  • Do not wait to see if symptoms go away.
  • Do not call your doctor.
  • Do not take aspirin. This will be given later if needed.
  • Do not drive yourself or wait for a ride to the hospital.
  • Do not delay making the call to 9-1-1.

The American Heart Association/American Stroke Association guidelines for initial care and treatment for stroke patients were revised and published in 2018. The recommendations are extensive and specific but the major points are summarized as follows:

The initial treatment for stroke is supportive.

• Patients usually will be given fluids through an IV because if they are having a stroke, they may often be dehydrated.
• Oxygen may be given to be sure that the brain is getting the maximal amount.
• If patients have any difficulty breathing, this will be assessed and treated.
• Unlike people with chest pain, people having a stroke are not given an aspirin immediately.
• Patients are asked not to eat or drink until their ability to swallow is assessed.
• Blood pressure control: Although blood pressure control is part of the prevention and treatment of strokes, it is important not to lower the blood pressure too much so that the brain will get enough blood. Many different medications can be used to lower the blood pressure including pills, nitroglycerin paste, or IV injections. If the blood pressure is very high, patients are placed on a continuous IV flow of medication.
  • Many people with stroke have very high blood pressure when they come to the emergency department. This may be due to an underlying problem or in response to the stroke. The doctor will assess the blood pressure and the type of stroke and decide if the blood pressure should be lowered.
• If patients have acute stroke, they will be admitted to the hospital for monitoring and further testing to figure out the cause of the stroke and ways to prevent a future stroke. People who have had a stroke are at greater risk than others of having an additional stroke.

• Drugs for acute stroke: Currently, only one medicine is approved to treat new strokes: a clot-busting medication called tissue plasminogen activator (tPA) that works with the body's own chemicals and helps dissolve the blockage in the brain's blood vessel that may be causing the stroke. The same drug that is often used to treat heart attacks, studies of tPA have shown that it can reduce disability from stroke by about 30%. It has potentially serious side effects that include bleeding within the brain. This usually occurs in people who have serious strokes or who were not going to do well regardless of treatment (see the illustration of how effective this drug is). Not all people with stroke can receive tPA.
  • For tPA to work, it must be given within 3 to 4 ½ hours of the onset of symptoms. The earlier the drug is given within those 3 to 4 ½ hours, the better it works. Symptom onset is defined as the time the patient was last known to be OK. If the patient awakens with symptoms, the symptom onset time is set back to the hour he or she went to sleep. This criterion alone may exclude many people from receiving this drug. This is also why it is so important to get to a stroke team for evaluation. Those excluded (>3 to 4 ½ hours) are "… patients over 80 years old, those on oral anticoagulants, those with a baseline NIHSS score >25, those with imaging evidence of ischemic damage to more than one-third of the middle cerebral artery (MCA) territory, and those with a history of both stroke and diabetes."
  • The patient must not have any evidence of bleeding on the CT scan of the head. Because tPA cannot be used for anyone having a hemorrhagic stroke, it is critical to know what kind of stroke the patient is having.
  • The doctor uses specific guidelines to evaluate whether the patient should receive treatment with this drug and will discuss the risks and benefits of giving it. If given, strict guidelines must be met for the administration of this drug to prevent bad side effects.
  • Ideally, tPA should be given within 60 minutes of the arrival of the patient.
• Other treatments for acute stroke are being tested. At some hospitals, clot-busting drugs are given through a small catheter that is threaded up into the neck and into the artery where there is a blockage. This treatment can potentially be used up to 6 hours after onset of stroke symptoms. Recently, three large studies compared this technique to the IV method and found no advantages, so this method may undergo revision. Many other new treatments for stroke are being developed. It may be possible to participate in a study of a new stroke drug or another acute treatment.

Surgical treatment for hemorrhagic strokes is sometimes done by neurosurgeons, depending on the stroke severity and the patient's condition. Surgical techniques may be used to stop the hemorrhage (bleeding) in the brain (for example, aneurysm clipping or coil embolization) and to remove blood that is causing increased pressure on brain tissue (decompressive craniotomy). In addition, some arteriovenous malformations (congenitally acquired tangled artery and vein connections that tend to bleed) may be treated with similar surgical techniques.

The American Heart Association published guidelines for acute ischemic strokes and endovascular treatment. It approved the use of a new catheter device that physically can remove blood clots. The catheter is termed an endovascular stent retrieval device that is capable of capturing a blood clot with a wire mesh that can then be removed from the patient thus opening up the vessel. However, the device requires special training and equipment, so some hospitals might not do this procedure yet. Moreover, the guidelines spell out parameters that need to be met by the patient's condition, especially having a clot blocking a large artery supplying blood to the brain. Limiting factors include having no significant disability before the current problem, having received tPA within 4.5 hours, being at least 18 years old, and having imaging scans that show more than half the brain on the stroke side is not permanently damaged.

Strokes are preventable! The most important thing you can do is to get your blood pressure checked and treated if you have high blood pressure.

• Have your blood pressure checked and monitored by a doctor. Even moderately high blood pressure over years can lead to a stroke.
• Treat high cholesterol with diet and exercise and then medication to reduce the risk of stroke. High levels of blood cholesterol known as LDL (low-density lipoprotein) increase risk for stroke and may cause the formation of artery-narrowing plaque.
• In people with certain irregular heart rhythms, such as atrial fibrillation, the use of blood thinners such as warfarin (Coumadin) has been shown to reduce the risk of stroke.
• For the general population, aspirin has not been shown to reduce stroke risk. It may be useful if prescribed by a doctor for people who have an increased risk of stroke.
• Control diabetes.
• Stop smoking or never smoke.
• Know the symptoms of stroke. Act quickly when someone exhibits the signs of a stroke. Stroke is a medical emergency.
• Surgically, some brain aneurysms can be treated if found before they bleed into the brain tissue.

Many people recover completely after a stroke. For others, it can take many months to recover from a stroke. Physical therapy and other retraining methods are greatly improving rehabilitation and recovery.

Despite clot-busting medications that help during an ischemic stroke, overall, about 30% of people die from stroke. In general, the more deficits or loss of ability (in walking or talking) individuals have when they arrive in the emergency department, the worse the outcome.