What is a Stroke? Here are the Facts
Stroke (also known as cerebrovascular disease) occurs when a blood vessel that carries oxygen and nutrients to the brain is either blocked by a clot or bursts. When that happens, part of the brain cannot get the blood and oxygen it needs, so it starts to die. The extent and location of the brain cell damage determines the severity of the stroke, which can range from minimal to catastrophic. Because different areas of the brain control different functions, the specific effects of a particular stroke depends on which area of the brain is injured. A small stroke in a critical area of the brain can be permanently disabling. Because brain cells do not regenerate, damage to the nerve cells is permanent. Millions of brain cells die each minute a stroke is untreated. Ruptured blood vessels cause hemorrhagic or bleeding strokes.
Stroke happens when the blood supply to part of the brain is cut off. Without blood, brain cells can be damaged or die. This damage can have different effects depending on where it happens in the brain. It can affect people's body, mobility and speech, as well as how they think and feel. Stroke devastates lives around the world.
Stroke is the leading cause of disability and the second leading cause of death globally. Stroke can happen to anyone at any age. Stroke affects everyone: survivors, family and friends, workplaces and communities.
Stroke Warning Signs
What are the warning signs of a stroke? Knowing the signs of stroke and getting treatment quickly saves lives and improves recovery.
Every minute counts. If you think someone may have had a stroke, do this BEFAST check:
If you notice any of these symptoms, don't wait. Dial 911 immediately and get to a hospital right away! Stroke is a medical emergency.
Types of Stroke
There are two types of stroke caused by an isolated blood vessel that hampers blood flow to the brain:
Ischemic stroke accounts for about 87 percent of all cases. Ischemic strokes occur as a result of an obstruction within a blood vessel supplying blood to the brain. The underlying condition for this type of obstruction is the development of fatty deposits lining the vessel walls. This condition is called atherosclerosis. These fatty deposits can cause two types of obstruction:
(1) Cerebral thrombosis refers to a thrombus (blood clot) that develops at the clogged part of the vessel.
(2) Cerebral embolism refers generally to a blood clot that forms at another location in the circulatory system, usually the heart and large arteries of the upper chest and neck. A portion of the blood clot breaks loose, enters the bloodstream and travels through the brain's blood vessels until it reaches vessels too small to let it pass. A second important cause of embolism is an irregular heartbeat, known as atrial fibrillation. It creates conditions where clots can form in the heart, dislodge and travel to the brain.
Hemorrhagic stroke Accounts for about 13 percent of stroke cases. It results from a weakened vessel that ruptures and bleeds into the surrounding brain. The blood accumulates and compresses the surrounding brain tissue. The two types of hemorrhagic strokes are intracerebral hemorrhage or subarachnoid hemorrhage.
Hemorrhagic stroke occurs when a weakened blood vessel ruptures. Two types of weakened blood vessels usually cause hemorrhagic stroke: aneurysms and arteriovenous malformations (AVMs).An aneurysm is a ballooning of a weakened region of a blood vessel. If left untreated, the aneurysm continues to weaken until it ruptures and bleeds into the brain. An arteriovenous malformation (AVM) is a cluster of abnormally formed blood vessels. Any one of these vessels can rupture, also causing bleeding into the brain.
Disorders after Stroke
The following disorders can occur in the aftermath of a stroke and they affect the majority of stroke patients:
Spasticity in the arm can cause a tight fist, bent elbow and arm pressed against the chest. This can seriously interfere with a stroke survivor's ability to perform daily activities such as dressing. Spasticity in the leg may cause a stiff knee, pointed foot and curling toes.
All of these disorders can be diagnosed and there are treatments available for most of them. Stroke is a complex medical issue. But there are ways to significantly reduce its impact. Recognize the signs of stroke early, treating it as a medical emergency with admission to a specialized stroke unit, and access to the best professional care can substantially improve outcomes.
Rehabilitation starts in the hospital as soon as possible following a stroke. It can improve function and help the survivor regain as much independence as possible over time.
One in four survivors will have another stroke. Treatments that prevent another stroke include drugs to lower blood pressure and cholesterol, antiplatelet therapies, anticoagulation for atrial fibrillation, surgery or stenting for selected patients with severe carotid artery narrowing.
Lifestyle changes can also greatly reduce the risk of another stroke. Changes include eating well, being physically active, being tobacco-free, managing stress, and limiting alcohol consumption.
- World Stroke Campaign
Longmont Stroke Support Group