At 3 a.m. the phone rings – it's the hospital calling to say that your brother has had a stroke. "Come quickly, it's serious". How can that be, you ask? Your brother is only 40 years old. But statistics show that your brother is not alone.
The numbers are staggering: According to the American Heart Association (AHA), stroke is the third-leading cause of death and one of the primary causes of long-term disability in the United States. Four out of every 1,000 people are affected by strokes each year, and there are over 4,000,000 stroke survivors alive at this time. Not just a disease for the elderly, 28 percent of stroke victims are under the age of 65, according to the Framingham Heart Study.
What is a stroke?
What does it mean to have a stroke? Let's first find out what happens in the brain:
Without a constant flow of oxygen-enriched blood, brain cells can become injured or destroyed (infarcted). A stroke, also known as a cerebrovascular attack (CVA) or brain attack, is an incident that occurs to any part of the brain when the blood supply is impeded. It can be gradual or sudden. Normal, everyday functioning of the body can be diminished or permanently lost after a stroke, and the symptoms will vary depending on the location and amount of brain tissue that is affected. Strokes are categorized as one of two types -- ischemic or hemorrhagic.
According to the National Stroke Association (NSA), 85 percent of all "brain attacks" are ischemic. Ischemia is a decrease in the blood supply to any body organ, caused by the obstruction or constriction of blood vessels. During an ischemic stroke, a cerebral artery or blood vessel in the brain is blocked. The blockage causes the death of brain tissue, and the resulting death of tissue is called an infarction. Ischemic strokes are subdivided into two types – embolic and thrombotic.
A clot that travels through the blood stream toward or within the brain is called an embolus, and the resulting blockage causes a stroke. An embolus usually originates in the heart or neck and travels to the brain. The blockage occurs suddenly and without warning, and the symptoms of an embolic stroke can occur within seconds to minutes of the actual infarct.
More common than embolic strokes, thrombotic strokes occur when a thrombus (or clot) blocks any of the arteries that furnish blood to the brain. Thrombotic strokes most frequently occur in larger arteries and are often linked to atherosclerosis.
Warnings of a stroke are called transient ischemic attacks (TIA). During a TIA, the blood supply to a part of the brain is stopped for a short period of time. The symptoms of a TIA are similar to those of an ischemic stroke (see below) and may last from several minutes to several hours. It differs from a true stroke because the brain tissue as a result of the TIA is not permanently damaged. A person may experience more than one TIA, but having even one TIA increases the chance of an eventual stroke by one-third. Approximately 10 percent of people who have a TIA will have a stroke.
Symptoms of ischemic stroke
According to the AHA, the symptoms or warning signs of ischemic stroke are as follows:
It is imperative to seek medical attention immediately if you experience any of these symptoms.
"Hemorrhage" means a loss of blood through ruptured or unruptured vessel walls. The sudden bursting of any blood vessel within the brain with the subsequent flow of blood into brain tissue is a hemorrhagic stroke. Although ischemic strokes occur more often than hemorrhagic strokes, the effects of a hemorrhagic stroke are much more devastating and more frequently fatal. Approximately one-third of all stroke related deaths are caused by hemorrhagic stroke. There are two types of hemorrhagic stroke -- intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH).
During an ICH, a blood vessel in the brain ruptures and blood leaks directly into brain tissue, injuring the brain. ICHs occur more often in men than women, in people 45 years of age and older, and more commonly in African-Americans than Caucasians. High blood pressure (hypertension) greatly contributes to an ICH, accounting for approximately 60 percent of all cases. Excessive alcohol consumption, certain recreational drugs (cocaine and amphetamines) and prescribed anticoagulants (heparin, for example) also can increase the occurrence of ICH.
Symptoms of an ICH
Symptoms occur rapidly and are not activity-related, but instead depend on the severity and location of bleeding in the brain. Some of the symptoms for ICH are similar to those for an ischemic stroke. According to the NSA, some or all of the following symptoms may occur before an ICH:
Nausea and vomiting may occur with any of these symptoms.
Less than 10 percent of all strokes are caused by SAHs. Although the ICH and SAH are similar, the cause, brain area, risk factors and symptoms are very different. During a SAH hemorrhage, blood leaks into the layer between the brain and the skull, without entering the brain itself, and puts pressure on the brain. A SAH may be caused by a head injury, but most commonly occurs when the wall of a blood vessel becomes thin and either tears or bursts (sometimes called an aneurysm).
SAH occurs most frequently in women, middle-aged people, African-Americans, and in those with a family history of ruptured aneurysms. Alcohol abuse and cigarette smoking also increase the risk for SAH. Overall, the symptoms for a SAH are different from other types of strokes.
Symptoms of a SAH
Nausea and vomiting also may occur with the above symptoms.
Effects of stroke on the brain
The brain is divided into three main sections: the cerebellum, the cerebrum -- divided into the left and right hemispheres, and the brain stem. The brain controls our every-day functioning and abilities, so the effects of a stroke can be devastating, ranging from temporary or mild to permanent or severely debilitating. The neurological deficits that result from a stroke are directly related to the area within the brain where the injury occurred and to the magnitude of the actual brain damage.
The cerebellum is responsible for most of our reflexes, balance and coordination. Nausea, vomiting, dizziness, abnormal reflexes, and coordination problems all result from strokes that occur in the cerebellum.
The left hemisphere of the cerebrum
The left side of the brain (or left hemisphere) is the dominant side of the brain for most people. It controls speech and language functions, as well as movement of the right side of the body. A person who has suffered a left hemisphere stroke may experience the following:
The right hemisphere of the cerebrum
The right side of the brain is responsible for the movement of the left side of the body; a stroke in the right hemisphere can cause left-sided hemiplegia. Other effects may include:
The brain stem
The brain stem controls all of our life support activities -- breathing, heartbeat and blood pressure. Many aspects of our senses also are also supported by the brain stem, such as hearing, eye movement, speech and swallowing. A stroke to the brain stem can cause vision impairments, the inability to swallow, paralysis and death.Sources
Mower DM, RN, CNRN, CS, MS. Brain Attack – Treating Acute Ischemic CVA. Nursing 97. March 1997.
Uphold CR, PhD, RNCS, ARNP, Graham MV, PhD, RNCS, ARNP. Clinical Guidelines in Family Practice – Third Edition. Barmarrae Books, July 1998:847-850.