How to prevent a stroke

How can I keep from having another stroke? — If you had an ischemic stroke—a stroke caused by a blocked artery in the brain—there are many things you can do to lower the chances of having another stroke.

If you had a transient ischemic attack, sometimes called a “mini-stroke” or TIA, you can also lower the chances that you will have a full-blown stroke.

To lower your risk of stroke, you should:

• Lower your blood pressure, if it is high
• Keep your blood sugar as close to normal as possible, if you have diabetes
• Lower your cholesterol, if it is high
• Stop smoking, if you smoke
• Do something active for at least 30 minutes a day on most days of the week
• Lose weight, if you are overweight
• Eat a diet rich in fruits, vegetables, and low-fat dairy products, and low in meats, sweets, and refined grains (such as white bread or white rice)
• Eat less salt (sodium)
• Limit the amount of alcohol you drink

• If you are a woman, do not drink more than 1 drink a day
• If you are a man, do not drink more than 2 drinks a day

Medicines and lifestyle changes work together to give the most benefit. It’s very important that you take all the medicines your doctor prescribes. It’s just as important to make the lifestyle changes your doctor recommends.

Take your medicines every day — If you had a stroke or TIA, your doctor or nurse will prescribe medicines to lower your risk of having another stroke. Some of these medicines work by “lowering your risk factors.” That means that they help lower blood pressure, blood sugar and cholesterol. Other medicines help by keeping blood clots from forming, which is what causes many strokes. 

Whatever medicines your doctor prescribes, make sure you take them every day as directed. If you cannot afford your medicines or if they cause side effects, talk to your doctor or nurse. There are often ways to deal with these problems.

Lifestyle changes — Lifestyle changes can do a lot to lower your risk of stroke. That’s partly because the right lifestyle choices can help control risk factors such as blood pressure, blood sugar, and cholesterol. To reduce your risk of stroke, make these lifestyle changes:

• Stop smoking, if you smoke (this is discussed in more detail below)
• Do something active for at least 30 minutes a day on most days of the week
• Lose weight, if you are overweight
• Eat a diet rich in fruits, vegetables, and low-fat dairy products, and low in meats, sweets, and refined grains (such as white bread or white rice)
• Eat less salt (sodium)
• Limit the amount of alcohol you drink

• If you are a woman, do not drink more than 1 drink a day
• If you are a man, do not drink more than 2 drinks a day

Stop smoking — If you smoke, ask your doctor or nurse about how to quit. There are strategies and medicines that can improve your chances of success. Studies show that people are most successful at quitting if they take medicines to help them quit and work with a counselor. You might also have a better chance at success if you combine nicotine replacement with one of the prescription medicines that help people quit.

You can also get help from a free phone line (1-800-QUIT-NOW) or online at www.smokefree.gov.

Transient Ischemic Attack (TIA) - The Basics

So we have discussed what is a stroke and hemorrhagic stroke now is the time for transient ischemic attack (TIA) or mini stroke.

What is a transient ischemic attack? — A transient ischemic attack (TIA) is like a stroke in that it causes the same symptoms as a stroke, but it does not damage the brain. TIAs happen when an artery in the brain gets clogged, or closes off, and then reopens on its own. This can happen if a blood clot forms and then moves away or dissolves. 

The symptoms of a TIA are the same as the symptoms of a stroke and can include:

• Weakness or numbness of the hand, tongue, cheek, face, arm, or leg
• Trouble speaking normally or at all
• Trouble seeing clearly with one or both eyes

TIA is sometimes called a “mini-stroke.” This is because a TIA is just like a stroke, except that a stroke causes long-lasting symptoms, while a TIA goes away quickly.

What is the difference between TIA and stroke? — A TIA does not cause permanent damage to the brain like a stroke does. But the symptoms are the same. This can make it hard to tell if a person is having a TIA or a stroke.

What causes a TIA? — Just like a stroke, a TIA can happen when the blood supply to part of the brain is cut off for a short time. This can happen if a blood clot blocks the flow of blood through an artery in the brain and then dissolves or moves away. It can also happen if one of the small arteries in the brain begins to close off from the effects of high blood pressure.

How can you tell if someone is having a TIA? — The symptoms of a TIA are the same as the symptoms of a stroke. There is an easy way to remember the signs of a stroke. Just think of the word “FAST” (by now you know the picture). Each letter in the word stands for one of the signs you should watch for:

• Face — Does the person’s face look uneven or droop on one side?
• Arm — Does the person have weakness or numbness in one or both arms? Does one arm drift down if the person tries to hold both arms out?
• Speech — Is the person having trouble speaking? Does his or her speech sound strange?
• Time — If you notice any of these stroke signs, even if they go away, call 9-1-1. You need to act FAST. The sooner treatment begins, the better the chances of recovery.

In the hospital, doctors can do tests to look for problems in the brain, blood vessels, and heart. This can help them choose the right treatment.

What is the risk of stroke after TIA? — A person who has had a TIA is at high risk of having a stroke. This risk is highest in the first few days to weeks after the TIA. That is why it is so important to get medical attention right away if you think you (or someone else) might have had a TIA.

How is a TIA treated? — TIAs are not usually treated directly. Instead, treatments are directed at reducing the risk that a person will go on to have a full-blown stroke. 

To lower your risk of stroke, you should:

• Lower your blood pressure, if it is high
• Keep your blood sugar as close to normal as possible, if you have diabetes
• Lower your cholesterol, if it is high
• Stop smoking, if you smoke
• Do something active for at least 30 minutes a day on most days of the week
• Lose weight, if you are overweight
• Eat a diet rich in fruits, vegetables, and low-fat dairy products, and low in meats, sweets, and refined grains (such as white bread or white rice)
• Eat less salt (sodium)
• Limit the amount of alcohol you drink

• If you are a woman, do not drink more than 1 drink a day
• If you are a man, do not drink more than 2 drinks a day

• Take your medicines exactly as directed. Medicines that are especially important in preventing strokes include:

• Blood pressure medicines
• Medicines to prevent blood clots, such as daily aspirin, warfarin (Coumadin®), and dabigatran (Pradaxa®) or apixaban (Eliquis®)
• Medicines called statins, which lower cholesterol such as atorvastatin (Lipitor®), simvastatin (Zocor®), or rosuvastatin (Crestor®)

Another way to prevent strokes is to have surgery to reopen clogged arteries in the neck. This surgery is appropriate for only a small group of people.





See "Transient Ischemic Attack" for more details on this topic.

Ischemic Stroke

As we have mentioned in prior posts the term ischemic stroke is used to describe a variety of conditions in which blood flow to part or all of the brain is reduced, resulting in tissue damage. Although in some cases this may be a chronic condition, most strokes occur acutely. Research over the last four decades has resulted in a significant expansion of our knowledge and understanding of the molecular and cellular processes that underlie ischemia-induced cellular injury.

The goal of this review is to provide an overview of the underlying factors, such as the hemodynamic changes and molecular and cellular pathways, which are involved in stroke-related brain injury.

STROKE SUBTYPES — Acute ischemic stroke subtypes are often classified in clinical studies using a system developed by investigators of the TOAST trial, based upon the underlying cause. Under this system, strokes are classified into the following categories:

• Large artery atherosclerosis
• Cardioembolism
• Small vessel occlusion
• Stroke of other, unusual, determined etiology
• Stroke of undetermined etiology

Ischemic strokes are due to a reduction or complete blockage of blood flow to some areas of the brain. This reduction can be due to decreased systemic perfusion, severe stenosis or occlusion of a blood vessel. Decreased systemic perfusion can be the result of low blood pressure, heart failure, or loss of blood. Determination of the type of stroke can influence treatment to be used. The main causes of ischemia are thrombosis, embolization, and lacunar stroke from small vessel disease. Ischemic strokes represent about 80 percent of all strokes. (See "Stroke Symptoms and Diagnosis")

• Thrombosis refers to obstruction of a blood vessel due to a localized occlusive process within a blood vessel. The obstruction may occur acutely or gradually. In many cases, underlying pathology such as atherosclerosis may cause narrowing of the diseased vessel. This may lead to restriction of blood flow gradually, or in some cases, platelets may adhere to the atherosclerotic plaque forming a clot leading to acute occlusion of the vessel. Atherosclerosis usually affects larger extracranial and intracranial vessels. In some cases, acute occlusion of a vessel unaffected by atherosclerosis may occur because of a hypercoagulable state.

• Embolism refers to clot or other material formed elsewhere within the vascular system that travels from the site of formation and lodges in distal vessels causing blockage of those vessel and ischemia. The heart is a common source of this material, although other arteries may also be sources of this embolic material (artery to artery embolism). In the heart, clots may form on valves or chambers. Tumors, venous clots, septic emboli, air and fat can also embolize and cause stroke. Embolic strokes tend to be cortical and are more likely to undergo hemorrhagic transformation, probably due to vessel damage caused by the embolus

• Lacunar stroke occurs as a result of small vessel disease. Smaller penetrating vessels are more commonly affected by chronic hypertension leading to hyperplasia of the tunica media of these vessels and deposition of fibrinoid material leading to lumen narrowing and occlusion. Lacunar strokes can occur anywhere in the brain but are typically seen in sub-cortical areas. Atheroma can also encroach on the orifices of smaller vessels leading to occlusion and stroke. (See "Lacunar Stroke".)

• Nonatherosclerotic abnormalities of the cerebral vasculature, whether inherited or acquired, predispose to ischemic stroke at all ages, but particularly in younger adults and children. These can be divided into noninflammatory and inflammatory etiologies. The following list, though not exhaustive, highlights the major nonatherosclerotic vasculopathies associated with ischemic stroke:

• Arterial dissection
  
• Fibromuscular dysplasia 
• Vasculitis 
• Moyamoya disease
• Sickle cell disease arteriopathy 
• Focal cerebral arteriopathy of childhood 

• Decreased systemic perfusion due to systemic hypotension may produce generalized ischemia to the brain. This is most critical in the borderzone (or watershed) areas, which are territories that occupy the boundary region of two adjacent arterial supply zones. The ischemia caused by hypotension may be asymmetric due to preexisting vascular lesions. Areas of the brain commonly affected include the hippocampal pyramidal cells, cerebellar Purkinje cells, and cortical laminar cells discussed below.

GENETICS OF STROKE — Many of the known risk factors for stroke are variable traits influenced by multiple genes, making it difficult to sort out the genetics behind them. The study of stroke genetics is also impaired by interactions between different risk factors that modulate their effects. It is widely accepted, however, that there is a genetic component to stroke that can lead to increased or decreased risk. Much of the evidence for this comes from studies of twins and from families with a history of stroke.

• Earlier studies of twins have been troubled by low sample numbers and poor classification of stroke type. However, these studies indicate that stroke-related death in one sibling is associated with a higher risk of stroke-related death in the other sibling among monozygotic (identical) twins versus dizygotic (fraternal) twins. This observation suggests that genetic factors shared by the monozygotic twins played a role in their strokes. 

• A family history of stroke is associated with an increased risk of stroke among the offspring. This has been observed for offspring with maternal and paternal histories of stroke, and among individuals having a sibling with a prior stroke.

Monogenic disorders — A number of monogenic syndromes are associated with an increased risk of ischemic stroke, including the following:

• Marfan syndrome and Ehlers-Danlos syndrome, which predispose to cervical artery dissection 
• Familial moyamoya disease 
• Fabry disease 
• Pseudoxanthoma elasticum
• Homocystinuria
• Menkes disease
• Cerebral autosomal dominant arteriopathy with subcortical infarctions and leukoencephalopathy
• Cerebral autosomal recessive arteriopathy with subcortical infarctions and leukoencephalopathy (CARASIL)
• Hereditary endotheliopathy with retinopathy, nephropathy, and stroke (HERNS)
• Sickle cell disease 
• Mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS)

It is important to note that all of these conditions together account for only a small percentage of ischemic strokes.

SUMMARY

• Under normal conditions, the rate of cerebral blood flow is primarily determined by the amount of resistance within cerebral blood vessels. Dilation of vessels leads to an increased volume of blood in the brain and increased cerebral blood flow, whereas constriction of vessels has the opposite effect. Cerebral blood flow is also determined by variation in the cerebral perfusion pressure.

• The brain is exquisitely sensitive to even short durations of ischemia. Multiple mechanisms are involved in tissue damage that results from brain ischemia. 

• Brain ischemia initiates a cascade of events that eventually lead to cell death, including depletion of ATP, changes in ionic concentrations of sodium, potassium, and calcium, increased lactate, acidosis, accumulation of oxygen free radicals, intracellular accumulation of water, and activation of proteolytic processes.

• Cell death following cerebral ischemia or stroke can occur by either necrosis or by apoptosis. Low levels of ATP within the core infarct are insufficient to support apoptosis, and cell death occurs by necrosis. In the ischemic penumbra, ATP levels are sufficiently high that cell death by apoptosis can occur. As the duration of ischemia increases, however, ATP levels are eventually depleted and the proportion of cells that undergo necrosis is increased.

What is a Stroke - The Basics

As a Stroke neurologist I see a lot of ischemic strokes and hemorrhagic strokes. However, many patients tell me that they were not sure if they should call 911. That is because they did not recognize the symptoms of a stroke. So this is a basic guide about what is a stroke.

Let's begin...

What is a stroke? — Stroke is the term doctors use when a part of the brain dies because it goes without blood for too long. Strokes can happen when the blood supply to a part of the brain is cut off, because:

• An artery in the brain gets clogged or closes off, or
• An artery in the brain starts bleeding.

How do strokes affect people? — The effects of a stroke depend on a lot of things, including:

• Which part and how much of the brain is affected
• How quickly the stroke is treated

Some people who have a stroke have no lasting effects. Others lose important brain functions. For example, some people become partly paralyzed or unable to speak. Stroke is one of the leading causes of death and disability in the United States. 

How can you tell if someone is having a stroke? — There is an easy way to remember the signs of a stroke. Just think of the word “FAST”. Each letter in the word stands for one of the things you should watch for:

• Face — Does the person’s face look uneven or droop on one side?
• Arm — Does the person have weakness or numbness in one or both arms? Does one arm drift down if the person tries to hold both arms out?
• Speech — Is the person having trouble speaking? Does his or her speech sound strange?
• Time — If you notice any of these stroke signs, call 9-1-1. You need to act FAST. The sooner treatment begins, the better the chances of recovery.

How are strokes treated? — The right treatment depends on what kind of stroke you are having, ischemic stroke or hemorrhagic stroke. To figure this out, you need to get to the hospital quickly.

People whose strokes are caused by clogged arteries (ischemic stroke) can:

• Get stroke medications that break up blood clots. These stroke medications can help reopen clogged arteries.
• Get medicines that prevent new blood clots. These medicines also help prevent a second stroke.

People whose strokes are caused by bleeding (hemorrhagic stroke) can:

• Have treatments that reduce the damage caused by bleeding in or around the brain
• Stop taking medicines that increase bleeding, or take a lower dose
• Have surgery to repair the artery or stop the bleeding (this is not always possible to do)

Can strokes be prevented? — Yes. To lower your risk factors for stroke, you should:

• Lower your blood pressure, if it is high
• Keep your blood sugar as close to normal as possible, if you have diabetes
• Lower your cholesterol, if it is high
• Stop smoking, if you smoke
• Do something active for at least 30 minutes a day on most days of the week
• Lose weight, if you are overweight
• Eat a diet rich in fruits, vegetables, and low-fat dairy products, and low in meats, sweets, and refined grains (such as white bread or white rice)
• Eat less salt (sodium)
• Limit the amount of alcohol you drink

• If you are a woman, do not drink more than 1 drink a day
• If you are a man, do not drink more than 2 drinks a day

• Take your medicines exactly as directed. Medicines that are especially important in preventing strokes include:

• Blood pressure medicines
• Medicines to prevent blood clots, such as daily aspirin, warfarin (brand name: Coumadin), and other newer medications that deal with atrial fibrillation (afib) and stroke
• Medicines called statins, which lower cholesterol

Another way to prevent strokes is to have surgery to reopen clogged arteries in the neck. This surgery is appropriate for only a small group of people.

What is a “TIA”, or mini stroke? — A TIA, or mini stroke, is like a stroke, but it does not damage the brain. TIAs happen when an artery in the brain gets clogged or closes off and then reopens on its own. This can happen if a blood clot forms and then moves away or dissolves. TIA stands for “transient ischemic attack.” (Check out "Transient ischemic attack" for more information on this very important disease)

Even though TIAs do not cause lasting symptoms, they are serious. If you have a TIA, you are at high risk of having a stroke. It's important that you see a doctor and take steps to prevent that from happening. Do not ignore the symptoms of a stroke even if they go away!

For those of you who need an in-depth review of Cerebrovascular Accidents and Stroke, I got you covered, check out “What is a Stroke –In-depth Overview”.