Stroke

Stroke Facts

Stroke is the third leading cause of death in America and the No. 1 cause of adult disability. According to the National Stroke Association, more than 750,000 Americans have a new or recurrent stroke every year, and incidence is on the rise. It is estimated that 5.4 million (or 1 in 55) Americans are living with the effects of stroke at any given time.

Myth:

Reality:

What is a stroke?

A stroke, insult "brain attack," occurs when a blood clot blocks an artery or a blood vessel breaks, interrupting blood flow to an area of the brain. Brain cells can die from decreased blood flow and the resulting lack of oxygen or due to increased pressure in the skull in the case of hemorrhage into the brain.

When brain cells die during a stroke, abilities controlled by that area of the brain are impaired. These abilities include speech, movement and memory. How a stroke survivor is affected depends on where the stroke occurs in the brain and how much of the brain is damaged. Some people recover completely from stroke, but more than two thirds of survivors eventually have some type of disability.

How do I know if I'm having a stroke?

If you have any of the following symptoms, call for emergency help immediately. The sooner you get help, the more doctors can do to prevent further or permanent damage.

  • Sudden weakness or numbness of the face, arm or leg on one side of the body
  • Sudden dimness or loss of vision, particularly in one eye
  • Loss of speech, trouble talking or understanding what others are saying
  • Sudden severe headache with no known cause
  • Unexplained dizziness, unstable walking or falling, especially along with any of the other symptoms

Another warning sign of a stroke is called a transient ischemic attack (TIA). A TIA is a "mini-stroke" that can cause the symptoms listed above and may only last a few minutes, but should not be ignored. People who have a TIA are at greater risk of having a stroke later. Call your doctor immediately if you think you are having a TIA.

What are the different types of stroke?

A stroke occurs when blood flow (and thus oxygen delivery) to a certain part of the brain is interrupted. This can occur by two mechanisms:

  1. Ischemic stroke can happen when a blood vessel in the brain is clogged by a blood clot or some other particle. Because of blockage part of the brain doesn't receive the blood it needs. Deprived of oxygen (ischemia), affected brain cells can't function and die within minutes. When brain cells can't function, the part of the body controlled by these cells can't function properly either. Stroke effects are often permanent because dead brain cells aren't replaced.
  2. Hemorrhagic stroke is caused by a ruptured (burst) brain blood vessel. When hemorrhage occurs, the loss of a constant blood supply means some brain cells can no longer function. Another problem is that accumulated blood from the burst artery may put pressure on surrounding brain tissue and interfere with how the brain functions. Severe or mild symptoms can result, depending on the amount of pressure.
  3. Approximately 80-85% of strokes are ischemic in nature while 15-20% are due to hemorrhage.

    Ischemic stroke is divided into 3 main categories:

    1. Thrombotic strokes occur when a clot (thrombus) forms within a brain blood vessel and blocks blood flow to that area of the brain. Clots are more likely to form on the inside of a brain artery that is injured or narrowed. Atherosclerosis is by far the most common cause of thrombotic stroke. Much less frequent causes may include dissection, vasculitis, conditions that cause blood to clot too easily. Thrombotic strokes cause about 70-80% of ischemic strokes (about 60% of all strokes).
    2. Embolic strokes occur when a blood clot breaks loose in some other part of the body, such as the heart atrium, travels to and lodges in a brain artery. Most embolic strokes originate from the heart, aorta, carotid or vertebral arteries. Conditions such as atrial fibrillation or valvular heart disease increase the risk of emboli. Embolic strokes account for about 15% of all strokes.
    3. Systemic hypoperfusion, occurring during a severe heart attack,heart arrhythmias or extreme blood loss, is failure of the heart to pump enough blood to the brain and can cause stroke. Hypoperfusion is less common than thrombosis or embolism as a cause of stroke.

    Hemorrhagic Stroke is divided into 2 categories:

    1. Intracerebral hemorrhage (ICH) accounts for about two thirds of hemorrhagic strokes (10-15% of all strokes). Bleeding occurs directly into the brain tissue, usually from small arteries (arterioles). Most ICH are associated with chronic high blood pressure.
    2. Subarachnoid hemorrhage (SAH) occurs when a blood vessel on the surface of the brain ruptures and bleeds into the space between the brain and the skull (but not into the brain itself). SAH is usually due to an aneurysm in the brain.

    Aneurysms are blood-filled pouches that balloon out from weak spots in the artery wall. They're often caused or aggravated by high blood pressure. Aneurysms aren't always dangerous, but if one bursts in the brain, a stroke results.

    Brain aneurysms (called berry aneurysms) usually occur at points where the brain arteries branch or are just about to enter brain tissue in an area known as the subarachnoid space. Rupture in this area is often very serious because the blood pressure is higher in this area than in smaller arteries that have already entered the brain tissue.

    SAH occurs half as frequently as ICH. Ruptured subarachnoid aneurysms cause about 5-7% of all strokes but cause a higher percent of strokes in younger people (under 40 years).

    They're often caused or aggravated by high blood pressure but may occur in young otherwise healthy people.

    Cerebral and subarachnoid hemorrhages have a much higher fatality rate than strokes caused by clots. The amount of bleeding determines the severity of cerebral hemorrhages. In 50 percent of the cases, people with cerebral hemorrhages die within the first month due to increased pressure on their brains. Those who live, however, tend to recover much more than those who've had strokes caused by a clot.

What are symptoms of a stroke?

Strokes affect different people in different ways depending on the type of stroke, the part of the brain affected and the extent of the brain injury. Stroke symptoms may include:

  • Sudden numbness or weakness of face, arm or leg, especially on one side of the body.
  • Sudden confusion, trouble speaking or understanding speech.
  • Sudden trouble seeing in one or both eyes.
  • Sudden trouble walking, dizziness, loss of balance or coordination.
  • Sudden, severe headache with no known cause. Often described as "feeling like my head is going to explode" or the worst headache of my life.

It is often not possible to tell what type of stroke (bleeding, thrombotic, or embolic) is occurring based on the symptoms a person is having.

Bleeding strokes are more likely to occur in younger people (under 40 years), be preceded by severe headaches and cause decreased consciousness or coma.

Embolic strokes are more likely in persons with existing heart valve disease, congenital heart defects, atrial fibrillation and other heart arrhythmias.

Thrombotic strokes are more likely in persons with known narrowing of neck or brain arteries (carotid artery stenosis) and prior stroke or TIA's with the similar symptoms.

What is a TIA or transient ischemic attack?

If blood flow is restored quickly any of the above signs may be only temporary and last from a few minutes up to half an hour. This may be due to a "little stroke" or "mini-stroke" called a transient ischemic attack or TIA

About 10 percent of strokes are preceded by TIA's. About a third of people who have had one or more TIA's will later have a stroke. A person who has had one or more TIA's is almost 10 times more likely to have a stroke than someone of the same age and sex who has not. Increasing frequency of TIA's may indicate an impending stroke. See your doctor immediately if your suspect TIA or TIA's are occurring more frequently.

How is a stroke diagnosed?

At the hospital, the emergency department staff or your doctor will check to see if you are having a stroke by:

  1. Asking you about your symptoms
  2. Testing the muscles of your body for strength, coordination and sensation.
  3. Performing a CT scan to determine what type of stroke you might be having
  4. Taking a blood samples to test for red blood cell count, blood sugar, electrolyte concentration, and how your blood clotting system works.
  5. Perform an EKG to see if a heart problem might be causing a stroke.

These tests should be performed as quickly as possible so optimal stroke treatment may be given.

If the emergency department staff suspects you are having a stroke they will hook you up to a heart monitor, place a catheter(s) in your vein(s), and give you additional oxygen through a tube attached under your nose.

Symptoms

Your doctor will want to know how long symptoms have been present and whether or not you have had a previous stroke or similar symptoms. If symptoms have been brief (less than several hours) and your stroke is not due to bleeding (hemorrhage) in the brain, clot dissolving medicine may be considered. Your doctor will want to know if you have a severe headache.

Physical exam

Strokes may produce certain patterns depending on the part of the brain involved. Knowing the severity of stroke symptoms is very important in deciding how aggressively to treat the stroke because certain treatments have serious side effects.

For example, treating a severely disabling ischemic stroke in an otherwise healthy person with a clot dissolving medication would likely be worth the increased risk of severe brain hemorrhage associated with the use of this medication. However, in a patient having a mild stroke with relatively little disability the risk of severe brain hemorrhage would outweigh possible mild benefits gained from use of clot dissolving medication.

CT scan is the most important test in majority of stroke patients because it can accurately tell whether or not a stroke is due to bleeding in the brain.

  • Should be performed in all patients suspected of having a stroke.
  • CT scan does not detect most ischemic strokes for at least 6 hours. However, it is excellent at detecting bleeding in the brain from hemorrhagic (burst blood vessel)strokes.

It is extremely important to determine what type of stroke (hemorrhagic or ischemic) you are having because treatment is different for each type. Blood thinners or clot dissolving medications used in ischemic strokes will make a hemorrhagic stroke worse!

Lab tests

  • Abnormally low blood sugar may mimic certain stroke symptoms.
  • Abnormally low or high electrolytes (sodium) may also mimic stroke symptoms.
  • Drugs, such as methamphetamine (speed) or cocaine, may cause stroke.
  • Blood cell count may indicate if blood is "thick", increasing risk of thrombotic stroke.
  • Blood of patients taking blood thinners may not clot normally, increasing the risk of hemorrhagic stroke.

ECG

  • Atrial fibrillation and heart attack cause a majority of embolic strokes. If either is detected on ECG it is much more likely that a stroke is from heart emboli. Treating the underlying heart problem will be important in both treatment and future stroke prevention.

Stroke Treatment

Surgery, drugs, acute hospital care and rehabilitation are all accepted ways to treat stroke. Treatment will depend on both type and severity of stroke. When a neck artery has become partially blocked, surgery might be used to remove the buildup of atherosclerotic plaque. This is called carotid endarterectomy . Cerebral angioplasty is a new experimental technique. Balloons, stents and coils are used to treat some types of brain blood vessel problems. Widespread use of these experimental techniques will require further study of safety and effectiveness.

Initial treatment of ischemic (thrombotic and embolic) strokes

Thrombotic and embolic strokes are due to blockage of blood flow from blood clots. Once it has been determined that a person is not having a bleeding stroke they may be given anticoagulant (blood thinning) or thrombolytic (clot dissolving) medications. These medications may include aspirin, heparin, or tissue plasminogen activator (TPA).

ASA (acetylsalicylic acid)

Low dose of ASA is given to almost all patients suffering from a nonbleeding stroke. ASA prevents platelets (part of the blood clotting system) from sticking together. ASA may decrease the severity of stroke and definitely decreases the risk of having another stroke. ASA is well tolerated by the most of people not allergic to it.

Thrombolytics (clot dissolvers)

Tissue plasminogen activators (TPA) are a clot dissolving medicines that has been used for some time in persons having heart attacks and some of them (alteplase) also for stroke treatment. It has recently shown great promise in treatment of ischemic stroke. Studies have shown that persons receiving TPA are more likely to have improved outcome than those not receiving TPA.

TPA must be used carefully and is not for all patients.

  • TPA may be indicated for patients having ischemic (thrombotic or embolic) stroke who seek treatment within 3 hours of the onset of symptoms.
  • A CT scan must be performed to exclude brain bleeding.
  • TPA cannot be used in persons with bleeding strokes, recent major surgery, extremely high blood pressure or in people taking oral anticoagulant (warfarin, coumadin).

Use of TPA increases the chance of converting an ischemic stroke into a bleeding stroke from 0.6% to 6%( 10 times) even when patients with contraindications are excluded from receiving TPA. About 50% of persons with TPA induced bleed will die or be severely disabled.

It is our opinion persons receiving TPA must fully understand the risks as well as benefits. For example, a person having a mild stroke with minimal loss of function must weigh the relative benefits versus the very real risk (1 in 18) of sustaining a much more severe stroke with TPA. This is a highly personal choice. A person's age, health and prior level of activity are all considerations.

Long term treatment (prevention) of ischemic strokes

The goal of long term treatment is to prevent either an initial or recurrent stroke. Type of treatment will depend on underlying cause.

ASA

Use of low dose of ASA on a daily basis has been shown to significantly decrease the frequency of TIA's and the likelihood of all types of ischemic stroke.

Anticoagulants

Long term use of oral anticoagulant after stroke has been replaced by ASA for most patients. They may be still used in persons at high risk of recurrent embolic stroke. Risk factors include atrial fibrillation, valvular or congenital heart disease.

Surgery

Narrowing of the carotid artery (neck artery) may cause wither TIA's or thrombotic stroke. When the carotid artery is narrowed more than 70-75% a surgical procedure, called carotid endarterecomy, has been shown to greatly decrease the risk of stroke due to carotid artery thrombus. If narrowing is less severe such surgery has not been shown to decrease stroke risk.

Initial treatment of hemorrhagic stroke

Management of hemorrhagic strokes is complex. Hemorrhagic strokes are associated with higher rates of death than ischemic strokes. Most intracerebral bleeds (ICB) are left alone. Accumulated blood from the burst artery puts pressure on surrounding brain tissue and interferes with how the brain functions. Severe or mild symptoms can result, depending on the amount of pressure. Surgery may be done persons with large bleeds who are alert but deteriorating. Doctors will gently lower extremely high blood pressure with medications.

Subarachnoid hemorrhages have the highest risk of rebleeding in the first 24 hours. In hospital management includes carefully controlling blood pressure and using certain medications that reduce spasm of brain arteries after hemorrhage has occurred. Angiography is usually performed to see where bleeding is coming from. In certain cases surgery may be done to "clip" the leaking blood vessel shut.

What are the physical and physiological effects of a stroke on a survivor?

Stroke can affect more than speech and mobility. The specific abilities that will be lost or affected by stroke depend on the extent of the brain damage and, most importantly, where in the brain the stroke occurred. Depression, memory loss, communication problems, difficulties in performing daily tasks, muscle tightness or spasticity, and pain – all of these may be among the conditions experienced by a stroke survivor.

What happens to the survivor, in terms of both immediate and long-term care, after a stroke?

Rehabilitation after stroke needs to begin in the hospital as soon as possible. The goal of rehabilitation is to improve function so that the stroke survivor may regain a level of independence. A recent supplement of Archives of Physical Medicine and Rehabilitation points out that earlier rehabilitation post-stroke promotes better outcomes.

Most survivors are served in a variety of settings by a variety of healthcare professionals, including:

  • primary care physicians
  • neurologists
  • physiatrists (physical medicine and rehabilitation)
  • physical and occupational therapists
  • nurses

These professionals work with survivors and caregivers to set realistic goals for rehabilitation.

What types of rehabilitation are available?

Thanks to better health education and medical advances, more people are surviving stroke. That means greater need for rehabilitation programs. Stroke rehabilitation varies from person to person. Survivors may be seen in a rehabilitation unit in the hospital, a sub-acute care unit, a rehabilitation hospital, or a long-term care facility providing therapy and skilled nursing care. Home therapy, or a combination of home and outpatient therapy, may also be rehabilitation options, depending on the stoke survivor’s individual needs.

Recovery progress is also variable. For some, recovery may take a few weeks. For others, recovery may take months or years.

Those who have suffered from stroke can experience severe spasticity. Severe spasticity, which affects approximately 38 percent of stroke survivors, is tight or stiff muscles that make movement – especially of the arms and legs – difficult or uncontrollable. Early treatment can make a significant difference to how severely someone is affected and to the long-term outlook after stroke. Severe spasticity can interfere with an individual's function and/or comfort. It can be very painful and can make simple activities of daily living (e.g., walking, eating, dressing, bathing) time- consuming and difficult for both the individual and caregiver. When spasticity limits activity for long periods, it can cause additional medical problems such as sleep disturbances, pressure sores and pneumonia.

For those who experience spasticity, physical or occupational therapy may be an option. There are also oral medications as well as injectable and implantable options available for those with severe spasticity, which may not appear until a year or more after a person sustains a stroke. Stroke survivors and caregivers are urged to ask their doctors about the latest rehabilitation therapies, which may improve their quality of life.

Managing spasticity can sometimes have dramatic and meaningful results on a stroke survivor’s ability to complete basic activities of daily living, such as bathing, dressing and walking.

What can the caregivers of those who have had a stroke expect?

Stroke does not just affect the person who had the stroke. In fact, four out of five American families are affected by stroke and caring for a stroke survivor can be a source of stress for family members.

Caregivers commonly worry that their loved one will have another stroke or may be placed in a nursing home. They may feel unprepared to face the responsibility of caring for their loved one. Stroke recovery is a lifelong journey that can be filled with both achievements and setbacks. And rehabilitation doesn’t just help the individual who suffered the stroke – it can be an important factor in helping the caregiver adjust to life after stroke as well. Caregivers can take steps to make the transition from hospital to home easier on everyone, such as encouraging independence, decision-making and participation in leisure activities. It is also important for caregivers to take an occasional break for themselves and to ask for help from family, friends or community organizations.

What are stroke recovery rates?

Stroke survivors experience a variety of outcomes based on age, severity of stroke, and success and timing of treatment. General recovery guidelines show:

  • 10% of stroke survivors recover almost completely
  • 25% recover with minor impairments
  • 40% experience moderate to severe impairments requiring special care
  • 10% require care in a nursing home or other long-term care facility
  • 15% die shortly after suffering stroke

The majority of those who experience stroke will need some form of rehabilitation in their recovery process. The goals of rehabilitation are to help survivors become as independent as possible and to attain the best possible quality of life. While rehabilitation does not reverse brain damage, it can substantially help people achieve the best possible long-term outcome.

Risk factors for a stroke

  • Atherosclerosis (hardening of the arteries)
  • Uncontrolled diabetes
  • High blood pressure
  • High cholesterol level
  • Smoking
  • Previous transient ischemic attack (TIA)
  • Heart disease
  • Carotid artery disease (disease of the artery that carries blood to your brain)

How can I avoid having a stroke?

Talk to your family doctor about your risk factors for a stroke (see box above) and how to reduce your risk. Here are some other things you can do to avoid having a stroke:

  • If your blood pressure is high, follow your doctor's advice to control it.
  • Avoid foods that are high in fat and cholesterol, and eat less sodium (salt), to lower your cholesterol and blood pressure.
  • If you have diabetes, keep your blood sugar level under control.
  • Limit how much alcohol you drink.
  • Quit smoking. If you don't smoke, don't start.

Acetylsalicylic acid (ASA) cardioprotective dose (75-100 mg) reduces the risk of having a stroke in those who have had a previous stroke or a transient ischemic attack (a temporary interruption of blood flow to the brain), which is often a warning sign of an impending stroke.

You may take low-dose (75-100 mg) ASA if you are not allergic to ASA and if there is no other reason that you can‘t take ASA. Talk to your doctor about whether taking ASA would help reduce your risk of recurrent stroke or TIA. Medicines containing low dose ASA, like Cardiopirin can help keep your blood from forming clots that can eventually block the arteries. Ask your doctor for advice on making these lifestyle changes, and ask friends and family for support. Regular check-ups are important to find problems that can increase your risk of having a stroke.


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