Stroke: A Detailed Overview

OVERVIEW

Stroke is the fourth leading cause of death in the United States, reports the Centers for Disease Control and Prevention (CDC). About 800,000 people have a stroke each year in the US alone.

drawing of the brain and where a blot clot could formA result of the blood supply to the brain being blocked, strokes usually make patients suddenly feel numb or weak on one half of the body. Because the blood flow to the brain is blocked, brain tissue can die during a stroke.

Although they are a leading cause of death, most strokes are preventable. Lifestyle factors like not smoking, exercising and keeping a healthy diet can all help.

Patients who believe they are having a stroke must immediately seek medical care through emergency services.

SYMPTOMS

Symptoms of stroke are usually very noticeable. For example, most stroke patients have trouble walking, speaking and seeing.

Stroke patients often experience paralysis or numbness in one half of the body. Other common symptoms include vomiting, sudden severe headache and confusion.

Patients who may be having a stroke should seek emergency medical care immediately. Do not wait to see if the symptoms dissipate. Because a stroke means blood flow to the brain is blocked or restricted, every passing minute increases the likelihood the patient will have permanent brain damage or die.

DIAGNOSIS

Many tests can help doctors diagnose a stroke. Doctors may want to conduct one of these tests to see whether a patient has had a stroke:

  • MRI, an imaging technique to find blood vessel blockage or other signs of stroke
  • Carotid ultrasound, another imaging technique that uses sound waves to create detailed images of the carotid arteries, which are large blood vessels in the neck
  • Carotid angiography, an imaging procedure in which a catheter is inserted into a blood vessel to inject dye to show doctors where a blockage might be

Doctors will also ask about any medications patients are taking and how long they have been having symptoms.

TREATMENTS

Immediate treatment for a stroke will focus on the blockage causing the stroke. This usually involves therapy with clot-busting medications started within a few hours of the stroke.

hds-signs-of-a-strokeOne common way doctors do this is by administering tissue-plasminogen activator (tPA) through a blood vessel in the arm. tPA, which works best if given within three hours of the stroke, works to dissolve the clot and boost blood flow. In some cases, doctors will insert a catheter (tube) into a blood vessel to try to administer tPA directly to the clot or remove the clot altogether.

After immediate treatment, doctors will focus on preventing future strokes. They will assess lifestyle and health factors that could raise stroke risk — smoking, high blood pressure and diabetes, for example. Doctors will counsel patients on how they can eliminate or reduce risk factors, such as by quitting smoking through a smoking cessation program or through prescription medications.

Depending on the severity of the stroke and the damage it caused, patients often need physical therapy after a stroke. Physical therapy can help with many post-stroke conditions. These include dysphasia (trouble swallowing), trouble walking, hemiparesis (muscle weakness on one side of the body) and limited coordination.

CAUSES

Strokes happen when the blood supply to the brain is blocked or reduced, which can keep the brain from getting the oxygen it needs.

There are two main types of major strokes — with slightly different causes.mri-ischemic-stroke

The first type, ischemic stroke, is a result of arteries leading to the brain being blocked. This is the most common type of stroke. Around 85 percent of all strokes are ischemic, according to the Mayo Clinic.

The underlying cause of an ischemic stroke is often the buildup of fatty deposits on blood vessel walls. Over time, this buildup can block blood flow to the brain and cause the blood to clot.

The second type of stroke is the hemorrhagic stroke. In this type of stroke, a blood vessel in the brain breaks or leaks. This stroke type accounts for around 13 percent of all stroke cases, according to the American Stroke Association.

Once a blood vessel in the brain has broken or has begun leaking, blood can accumulate in the brain and put pressure on surrounding brain tissue.

GETTING HELP

Anyone who thinks he or she is having a stroke should seek emergency medical care immediately.

In general, the faster stroke treatment begins, the better the outcome.

RELATED INFORMATION

A transient ischemic attack is a very brief period in which the patient experiences symptoms of a stroke.

This type of stroke is also known as a “mini-stroke.” It is caused by a temporary blockage of blood flow to the brain. The difference between this type of stroke and an ischemic attack is that the transient ischemic attack is temporary — most last less than five minutes, according to the American Stroke Association. They don’t usually cause permanent brain damage.

Patients should not respond to transient ischemic attacks any differently than they would respond to a stroke. They should seek medical care — even if their symptoms go away. These mini-strokes can signal more serious strokes down the road. The American Stroke Association reports that about one-third of people who have a mini-stroke have a stroke within a year of the initial attack.

LIVING WITH

Many people who have strokes recover fully within weeks or months. Some, on the other hand, can have lifelong disabilities because of a stroke.

Many stroke patients have trouble speaking or communicating after a stroke. The Mayo Clinic recommends regular practice, props and other communication aids and joining a support group to deal with the potential frustration of not being able to function easily.

After having a stroke, many patients seek the support of friends and family, who can help them deal with their recovery and manage their health to prevent another stroke.

References
National Institutes of Health, “NINDS Stroke Information Page”
http://www.ninds.nih.gov/disorders/stroke/stroke.htm
MedlinePlus, “Stroke”
http://www.nlm.nih.gov/medlineplus/stroke.html
Mayo Clinic, “Stroke”
http://www.mayoclinic.org/diseases-conditions/stroke/basics/definition/con-20042884
Centers for Disease Control and Prevention, “Stroke”
http://www.cdc.gov/stroke/
American Stroke Association, “Hemorrhagic Strokes (Bleeds)
http://www.strokeassociation.org/STROKEORG/AboutStroke/TypesofStroke/HemorrhagicBleeds/Hemorrhagic-Strokes-Bleeds_UCM_310940_Article.jsp
American Stroke Association, “TIA (Transient Ischemic Attack)”
http://www.strokeassociation.org/STROKEORG/AboutStroke/TypesofStroke/TIA/TIA-Transient-Ischemic-Attack_UCM_310942_Article.jsp