Hemorrhagic Vs. Ischemic Stroke

Hemorrhagic and ischemic strokes differ but both are serious medical conditions

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

When it comes to a health problem as serious as stroke, it's good — and potentially lifesaving — to stay informed.

Stroke is the fifth leading cause of death in the United States, according to the Centers for Disease Control and Prevention (CDC). A stroke is a medical emergency and must be treated immediately.

Managing other conditions like high blood pressure can reduce your risk of stroke, and there are also other lifestyle factors under your control. Strokes come in two basic versions: hemorrhagic and ischemic.

Most strokes in the US are ischemic strokes, according to the CDC.

Hemorrhagic Stroke

A hemorrhagic stroke is caused by bleeding in the brain.

Chaouki Khoury, MD, a neurologist and director of neurology education and research at Baylor University Medical Center in Dallas and an associate professor of neurology at Texas A&M, told dailyRx News that "Hemorrhagic strokes are due to weakening of the blood vessels ... most commonly because of very high blood pressure that is not being treated or being treated but not enough."

Other possible causes, according to Dr. Khoury, "include certain vascular malformations; the blood vessels are formed wrong." He added, "There's a third condition that occurs in older patients called amyloid angiopathy. It's the same disease process as in Alzheimer's, where you have amyloid deposits in the blood vessels, leading to the blood vessels being weak and leaking on their own."

Intracerebral hemorrhagic strokes are usually caused by chronically high blood pressure or aging blood vessels.

Another type of hemorrhagic stroke is called a subarachnoid hemorrhage. This occurs when a weak portion of an artery on or near the surface of the brain balloons out and breaks.

Intracerebral strokes cause bleeding inside the brain tissues, while a subarachnoid stroke causes bleeding between the brain and the arachnoid membrane that covers the brain.

Ischemic Stroke

An ischemic stroke occurs when a blood vessel in the brain becomes blocked. Ischemic strokes may be thrombotic or embolic.

In the first, a blood clot occurs in an artery going to the brain. These usually occur in an area damaged by plaque, a thick fatty deposit in the artery.

Embolic strokes occur when a clot forms somewhere else in the body — usually in the head or neck arteries — and travels to the brain.

Dr. Khoury added, "Ischemic strokes occur for one of three reasons — either you have a heart condition that predisposes you to form blood clots that then travel up to the brain and cause the stroke, or you have disease of the blood vessels themselves, such as blood vessels that are damaged by high blood pressure, diabetes, [or] high cholesterol with cholesterol deposit on the inner surface of the blood vessels causing narrowing and blood clot formation."

Some people develop diseases or have inherited conditions that can make the blood more likely to clot, Dr. Khoury said.

If that's the case, Dr. Khoury said, "you have a condition where the blood itself has a tendency to clot. This can be either genetic — these are people who have an inherited condition that causes the blood to clot — or it's acquired. People with cancers, for example, their blood tends to clot more. People with certain leukemias can have their blood clotting more."

Making a Diagnosis

Doctors diagnose both types of stroke in the same way. First, the doctor does a physical assessment and collects a patient history.

Next, the patient has a CT scan or an MRI to determine whether there is bleeding or a clot and exactly where the problem is. The doctor may also order lab or other diagnostic tests.

Imaging tests provide a picture of the brain, similar to that of an X-ray. An electrical test called an electroencephalograph, or EEG, shows the electrical activity of the brain. An arteriogram can show what the brain’s blood flow looks like.

Stroke Treatment

Once the tests show what type of stroke the patient has had, treatment begins. In all cases, treatment must begin as soon as possible to prevent permanent disability or death.

If a hemorrhagic stroke is caused by an arteriovenous malformation (AVM), the surgeon will remove the cluster of deformed blood vessels. When the stroke is caused by an aneurysm, the doctor will repair the break in the artery.

Ischemic strokes can be treated with an intravenous medication that helps dissolve the clot. Tissue plasminogen activator, or tPA, is the only medication approved by the US Food and Drug Administration to treat ischemic stroke.

tPA must be given within 4.5 hours of the first stroke symptoms. Only about 5 percent of patients who have a stroke receive tPA because most don't arrive in a stroke center until 12 to 24 hours after the first symptoms.

Other treatments include using a tiny catheter to remove a clot from the brain or putting in a small metal tube called a stent to widen the narrowed artery. In balloon angioplasty, a tiny balloon is inserted into the artery and inflated to compress the plaque and allow blood to flow more freely.

Doctors may also use other medications to control brain swelling for either type of stroke. Stroke treatment is complex, and the patient must be carefully monitored in an intensive care unit.

What's the Risk?

Your risk of stroke varies according to your age, ethnicity and other factors. Smoking, high cholesterol and high blood pressure — especially if your blood pressure is not being treated or is not under control — are the major risk factors for stroke. The CDC says around half of all Americans have at least one of these risk factors.

The risk of a first stroke is nearly twice as high for blacks as it is whites, according to the CDC. The average risk Hispanics face is roughly in the middle of that of blacks and whites.

Although strokes are more likely to occur in older people, about a third of the people hospitalized for stroke in 2009 were younger than 65, according to the CDC.

People who live in the southern part of the US are more likely to die from stroke than those in other areas, according to the American College of Cardiology. People who live in the southern states are more likely than those who live in other areas to smoke, be obese, have high cholesterol or have high blood pressure — all risk factors for stroke.

An Ounce of Prevention

Although strokes from AVMs are due to genetic factors, the CDC says you can help protect yourself from other kinds of stroke by making healthy lifestyle choices. One of the most important of these is to not smoke or use tobacco in any form.

Obesity raises your risk of stroke and high blood pressure. Regular exercise helps keep your blood pressure under control and can help you manage your weight.

A healthy diet provides you with the important nutrients you need to stay healthy and helps keep your weight under control.

Limit your alcohol intake. Men should have no more than two drinks a day, and women should have no more than one drink a day. Speak to your doctor about safe levels of alcohol consumption.

Get Immediate Treatment

If you do have a stroke, prompt treatment may increase your chance of survival and decrease complications.

There's no time to waste, according to Dr. Khoury.

"If all of a sudden you lose vision on one side ... or you lose the ability to talk or understand speech ... going weak on one side, going numb on one side all of the sudden or losing coordination on one side ... these are things people need to be aware of so, if that happens, they immediately call 911," Dr. Khoury said.

Review Date: 
May 8, 2015