A stroke happens when blood flow to the brain is suddenly interrupted or decreased, starving the brain of oxygen and nutrients. This can happen when arteries leading to the brain become blocked or when a blood vessel bursts and causes bleeding into the brain.
A stroke, sometimes called a brain attack, can kill brain cells within just minutes, after decreased blood flow to the brain starves them of oxygen. People having a stroke require immediate medical attention. Acting quickly can limit brain damage or prevent death.
Strokes are a leading cause of death in the United States and their prevention is a key component of cardiovascular health.
Strokes can cause temporary or permanent disabilities depending on how long the blood flow to the brain is interrupted. These may include paralysis or lack of muscle control, difficulty talking and swallowing, memory loss, pain, and changes in behavior or the ability to take care of oneself.
Controlling your risk factors for stroke and knowing what to do in the event of a stroke are the two best ways to avoid or survive a stroke.
Types of Stroke
There are three types of stroke – ischemic, intracerebral hemorrhagic and subarachnoid hemorrhagic – as well as a similar condition often referred to as a “mini-stroke.”
Ischemic strokes happen when a blood clot blocks a blood vessel in the brain. This is the most common type of stroke, responsible for about 80 percent of all strokes, according to the National Institutes of Health.
Fatty deposits lining the walls of arteries are responsible for the blood clots that cause most ischemic strokes.
- Cerebral thrombosis
- A blood clot that develops at the fatty plaque inside a blood vessel at the site of the stroke
- Cerebral embolism
- A blood clot that forms in some other part of the body before breaking loose and traveling to the brain’s blood vessels. Atrial fibrillation is a primary cause of cerebral embolism, causing the formation of blood clots in the heart that dislodge and travel to the brain
Source: American Stroke Association
Intracerebral Hemorrhage Stroke
Intracerebral hemorrhages occur when a blood vessel in the brain bursts, allowing blood to leak into the brain. The sudden buildup of pressure from the leaking blood can cause unconsciousness or death in a short amount of time.
This type of hemorrhagic stroke is responsible for about 10 to 15 percent of all strokes. The one-year mortality rate for people who have this type of stroke is between 51 and 65 percent, according to a 2011 review published in the Journal of the Missouri State Medical Association.
Subarachnoid Hemorrhage Stroke
Subarachnoid hemorrhages happen when a burst blood vessel in the head causes bleeding in the space between the brain and the membrane that surrounds it. It may sometimes be caused by trauma or abnormal blood vessel formations.
The main symptom is a sudden, severe headache that is sometimes accompanied by nausea, vomiting and brief unconsciousness. It can result in permanent brain damage or death without medical attention.
What Is a ‘Mini-Stroke?’
Mini-strokes are not technically strokes but a condition similar to them. The medical term for a mini-stroke is a transient ischemic attack, or TIA.
TIAs happen when the brain’s blood supply is temporarily blocked for a very short time, sometimes as little as five minutes. TIA’s don’t cause permanent brain damage, but they are an indication of an increased risk of an actual stroke.
The symptoms may be similar to a stroke, but they go away quickly. You should seek medical attention if you think you have suffered a mini-stroke to reduce your risk of a stroke in the future.
Signs and Symptoms
Your body can provide you and those around you with warning signs that you are having a stroke. These are the result of your brain being starved of its oxygen supply. If you notice any of these signs, you should call 911 immediately.
- Sudden confusion – May also include trouble talking or understanding what others are saying
- Sudden numbness or weakness – Especially apparent on one side of your body or in the face, arms or legs
- Sudden severe headache – Especially if there’s no known or obvious cause
- Sudden vision problems – May be trouble seeing with one or both eyes or double vision
- Sudden trouble walking – May include dizziness or loss of balance and coordination
Source: National Institute of Neurological Disorders and Stroke
In some cases, people having a stroke may also experience drowsiness, nausea or vomiting.
Warning signs of a stroke may last for only a few moments before disappearing. These are indications of mini-strokes. Because they are so short-lived and appear to have no lasting effects, many people ignore them. But they can be an important warning sign of a serious underlying condition that requires medical attention.
Act ‘FAST’ When a Stroke Happens
Fast action is key to surviving a stroke. Patients who are diagnosed and can begin treatments within three hours of their first symptoms have the best chance of recovery.
The letters F, A, S and T are key reminders on what to do if you think someone is having a stroke.
- F for Face: Ask the person to smile. If one side of the face droops, it’s a sign of stroke.
- A for Arms: Ask the person to raise both their arms. If one drifts down, it’s a sign of stroke.
- S for Speech: Ask the person to repeat a simple phrase. If the speech is slurred, slow or unusual, it’s a sign of a stroke.
- T for Time: If you see any one of these signs, don’t waste time – call 911 immediately.
Source: U.S. Centers for Disease Control and Prevention
Check your watch or a clock and note the time that you first noticed symptoms. This will help emergency room personnel determine the best treatment.
Causes and Risk Factors
Several factors play into a person’s risk for stroke including lifestyle, underlying medical conditions and even a person’s age, race and sex.
- High blood pressure – This is the leading risk factor for stroke
- Diabetes – Extra sugar in the blood can increase fatty deposits on the artery walls, raising the chances of blood clots
- Heart disease – Atrial fibrillation can cause blood clots leading to stroke. Heart failure, defects or infection can also be risk factors
- High cholesterol – This creates fatty deposits inside blood vessels that can lead to blockages
Sleep apnea and a family history of stroke, heart attack or TIA are also medical factors that increase the risk of stroke.
- Smoking or secondhand smoke exposure
- Physical inactivity
- Excessive drinking
- Obesity or being overweight
- Illegal drug use
- Unhealthy diet
Other factors of increased stroke risk include age, race and sex.
People 55 and older are at a higher risk than younger people. African Americans have a higher risk of stroke than people of other races. Men have a higher risk than women. Women are generally older when they do have strokes, but are more likely to die of a stroke than men are.
Medications That May Increase Stroke Risk
Though side effects involving stroke are rare, some medications may increase the risk of stroke in certain cases.
- Alemtuzumab – Lemtrada, used to treat relapsing forms of multiple sclerosis, has a black box warning on its label warning of increased stroke risk
- Estrogen – Birth control pills or hormone therapies that include estrogen have been linked to increased risk of stroke
- Testosterone – In 2015, the U.S. Food and Drug Administration ordered makers of testosterone replacement therapies, such as AndroGel and Testim, to add a warning of increased stroke risks to the drugs’ labels
How to Prevent a Stroke
Preventing a stroke requires that you follow healthy living habits and control your other medical conditions.
- Stick to a healthy diet, low in fats and cholesterol and salt
- Get to a healthy weight where you are not overweight or obese
- Quit smoking
- Limit alcohol use
Source: U.S. Centers for Disease Control and Prevention
Controlling other health conditions can increase your chances of preventing stroke. Following your doctor’s or other health care provider’s recommendations for controlling any or all of those conditions can also reduce your risk of having a stroke.
Medications Used for Preventing Strokes
Doctors may place people who have experienced a TIA or mini-stroke on medications to reduce their risk for a full-blown stroke. The drugs fall into one of two classes: antiplatelet drugs and anticoagulants.
Platelets are the cells in the blood that form clots. Antiplatelet drugs make the cells less sticky and therefore less likely to form a clot. The most common antiplatelet drug is aspirin. A doctor may prescribe Plavix (clopidogrel), another antiplatelet drug, to take along with aspirin for a short time. Or they may prescribe Plavix alone if a person can’t take aspirin.
Anticoagulants are commonly referred to as blood thinners and prevent blood from clotting. Doctors may prescribe different anticoagulant drugs depending on how serious a person’s stroke risk may be.
Diagnosis and Treatment
Health care providers have to act quickly to diagnose and treat strokes. The longer treatment is delayed, the more serious the consequences may become.
Diagnosis involves a physical examination and a selection of blood tests and imaging. Doctors may use CT or MRI scans to view the brain. A carotid ultrasound can provide images of blockages in the neck’s carotid arteries. An echocardiogram, using soundwaves to create images, can paint a picture of the patient’s heart to look for blood clots that may have broken loose.
These different tests can help medical teams determine what kind of stroke they are dealing with.
Treating Ischemic Strokes
In the event of an ischemic stroke, health care professionals may provide intravenous medications to break up a clot. But this has to be accomplished within four and a half hours of the first symptoms.
Doctors may also treat the blockage by intervening directly in the blocked artery. This is called endovascular therapy. These procedures involve using long, thin tubes called catheters to deliver medications directly to the brain or to insert a device into the artery to remove the clot.
Treating Hemorrhagic Strokes
Health care professionals focus on quickly controlling the bleeding and reducing pressure on the brain in cases of hemorrhagic strokes.
Treatment may involve efforts to get the blood to clot to stop the bleeding into the brain.
It may also include surgery to remove the blood and pressure on the brain or to clip the artery and stop the bleeding.
Rehabilitation Following Stroke
Most people will require rehabilitation to fully recover from a stroke. Rehabilitation programs will vary from person-to-person.
Any program will take into account the patient’s age, health and the particular disabilities arising from the stroke.
Patients should work with their doctor and other health care professionals on a plan that’s right for them.
Please seek the advice of a medical professional before making health care decisions.