Stroke is the fourth leading cause of death in America and the #1 cause of adult disability.
A stroke occurs when a blood clot blocks an artery or when a blood vessel breaks interrupting the blood flow to an area of the brain. When either of these things happen, brain cells begin to die, which causes brain damage.
When brain cells die, abilities controlled by that area of the brain are lost. Such abilities may include speech, movement and memory. The effect of stroke on a patient depends on where the stroke occurs in the brain and how much damage there is.
There are several types of strokes, each with different causes and effects. The three main types of stroke are:
Ischemic stroke is a type of stroke that accounts for about 83 percent of all cases, according to the American Stroke Association. Ischemic strokes occur as a result of an obstruction within a blood vessel supplying blood to the brain.
This blockage may stem from several sources, including clots from the heart or legs, plaque from the valves of the heart or other blood vessels. If a clot or plaque breaks free and travels to the brain, stroke occurs. An ischemic stroke can occur in two ways: embolic and thrombotic strokes.
Transient Ischemic Attack (TIA)
A TIA is sometimes called a '”mini-stroke.” It is usually due to a blockage caused by platelets clumping together. After a short period of time, these clumps break up, allowing the blood flow to resume and the symptoms resolve. Having experienced a TIA increases the chance that a patient will experience a full-blown stroke. It is important to determine the cause of the symptoms and thereby reduce the risk of stroke.
Hemorrhagic stroke accounts for about 17 percent of stroke cases, according to the American Stroke Association. In hemorrhagic strokes, a blood vessel in the brain leaks or ruptures. Hemorrhagic stroke can be caused by a number of disorders which affect the blood vessels, including arteriosclerosis and long-standing high blood pressure. Two types of weakened blood vessels usually cause hemorrhagic stroke: aneurysms and arteriovenous malformations (AVMs).
Stroke symptoms appear suddenly. Watch for these stroke symptoms and be prepared to act quickly whether for yourself or someone else:
- Sudden numbness or weakness of the face, arm, or leg, especially on one side of the body
- Sudden confusion, trouble talking, or understanding speech
- Sudden trouble seeing in one or both eyes
- Sudden trouble walking, dizziness, or loss of balance or coordination
- Sudden severe headache with no known cause.
Can you recognize the stroke symptoms? Remember to think and act F.A.S.T. by doing this test.
F=Face Ask the person to smile. Does one side of the face droop?
A=Arm Ask the person to raise both arms. Does one arm drift downward?
S=Speech Ask the person to repeat a simple phrase. Does the speech sound slurred or strange?
T=Time If you observe any of these signs, it’s time to call 9-1-1. Studies show stroke
patients who arrive at the hospital by ambulance receive quicker treatment than
those who arrive on their own.
If you think someone may be experiencing stroke symptoms, act F.A.S.T. and call 911.
Patients and their families are understandably very concerned about what specific abilities will be lost or affected by stroke. Stroke effects are difficult to assess, because the brain is an incredibly complex organ, and each area has responsibility for a particular function or ability.
The nature and extent of the effects of a stroke depends upon the extent of injury and where the stroke occurred. Strokes that occur in the right side of the brain typically affect movement of the left side of the body and can interfere with analytical and perceptual tasks. Strokes that occur in the left side of the brain can affect the movement of the right side of the body and can influence speech and language abilities.
Strokes that occur in the cerebellum can cause coordination problems, dizziness, nausea and vomiting. Strokes that occur in the brain stem can affect life-support functions such as breathing, vision, level of consciousness and the ability to swallow in addition to causing numbness and paralysis.
Evaluation and Diagnosis
Physicians have several diagnostic techniques and imaging tools to help diagnose the cause of stroke quickly and accurately to mitigate stroke effects.
The first step in diagnosis is a neurological examination. When a possible stroke patient arrives at a hospital, a health care professional, usually a doctor or nurse, will ask the patient or a companion what happened and when the symptoms began. Blood tests, an electrocardiogram and a brain scan, such CT or MRI, will often be done.
One test that helps doctors judge the severity of a stroke is the standardized National Institutes of Health Stroke Scale. Health care professionals use the NIH Stroke Scale to measure a patient's neurological deficits by asking the patient to answer questions and to perform several physical and mental tests. Other scales can also be used to measure the severity of a stroke.
Studies used in evaluation of stroke may include:
Peripheral vascular studies, also known as “doppler ultrasound."
This noninvasive procedure can detect blockages that may be present in the carotid arteries by detecting an increased velocity of red blood cells over narrowed sites. The test measures the blood flow through the artery to determine the amount of stenosis (blockage), plaque or irregularities in the artery.
This noninvasive test conducted on your heart transmits pulses of sound into the body, then electronically plots and records the echoes returning from the surfaces of the heart. It measures the function and strength of the heart muscles and valves to detect whether or not a blood clot in the heart or on the heart valves is the source of the stroke.
These studies involve drawing and analyzing the blood to determine your body's ability to coagulate (or clot).
CT (Computed Tomography) scan
A CT is the most commonly used diagnostic technique for acute stroke. If a stroke is caused by hemorrhage, a CT can show evidence of bleeding into the brain almost immediately after stroke symptoms appear. It can occasionally show a tumor that might mimic a stroke and may even show evidence of early infarction (the death of tissue due to inadequate blood supply).
MRI (Magnetic Resonance Imaging)
MRI scanning is very helpful in detecting stroke and displaying the extent of brain damage that has occurred. Because the MRI ignores bone which can obstruct CT images, this device provides a clearer picture of tumors located near the bone, and can provide a wider variety of image angles. It can detect edema (swelling), but has difficulty distinguishing edema from a tumor, and will not be able to detect the specific type of tumor.
This is a procedure in which a contrast dye is injected into the blood vessels that supply the brain. An angiogram is the best way to detect an aneurysm or other vascular malformation.
When you have a stroke, every second counts. Through fast and expert intervention, Martha Jefferson works to save brain cells that can make the difference in your future quality of life.
A team of stroke experts is on hand at Martha Jefferson hospital 24/7, ready to respond immediately to patients who present with a recent stroke. A coordinated series of studies are performed to evaluate the patient and establish whether or not a stroke is actually happening and if so, what is the best course of treatment.
The most effective stroke treatments can only be given within the first few hours after a stroke has occurred. At Martha Jefferson Hospital, we offer intravenous tPA (tissue plasminogen activator) within 4.5 hours of the onset of symptoms for patients suffering from an ischemic stroke. tPA dissolves the clots that cause ischemic stroke.
Of course, the best treatment for stroke is prevention.
Up to 80 percent of strokes are preventable.
The risk factors for stroke include: diabetes, high blood pressure, elevated cholesterol, obesity, tobacco use, excessive use of alcohol, sedentary lifestyle, previous stroke or transient ischemic attack (TIA), a history or new onset of irregular heartbeats (atrial fibrillation or atrial flutter) and a family history of stroke.
To help you avoid a stroke, we can help you address your risk factors for stroke, and offer ways to modify those risks. Martha Jefferson offers dietary counseling, diabetic counseling, tobacco cessation counseling, as well as medications that are available to treat those risk factors not responsive to lifestyle changes.