Stroke, Part Two: A Patient Guide
Diagnosing a stroke
Any type of stroke is considered a medical emergency and requires urgent medical assistance, because immediate treatment can make the difference between life and death. Your treatment will hopefully restore blood flow to the affected area of the brain, stabilize your condition and ensure that increased intracranial pressure (ICP) is prevented. Therefore, the initial diagnosis, ongoing assessment and treatment can play a vital role in the overall outcome of a stroke.
Before diagnosing a stroke, a physician will determine your complete medical history and risk, and perform a complete physical exam. Also, he or she will note the severity, frequency, pattern of symptom development and duration of symptoms. (For example, did the symptoms occur suddenly or gradually? Early or late in the day? And were the deficits most apparent at the onset of symptoms or did they develop gradually?) If you are unable to provide the physician with the fine details of your symptoms, it is important to have a family member or friend accompany you to the emergency room who can.
Knowing what to expect from a physical exam may help you feel more comfortable. During the physical exam, your vital signs will be taken and monitored closely. Your blood pressure will be measured in both a sitting and lying position, because many stroke patients will have an elevated blood pressure. Your doctor will use a stethoscope to listen for abnormal sounds in the carotid and peripheral arteries. He or she will also listen closely to your heart and lungs and assess your swallowing function (since impaired swallowing predisposes you to development of pneumonia). Your mental status will also be closely monitored to show changes in levels of consciousness (LOC) that may indicate ischemia (a decreased blood flow resulting in decreased oxygen flow) or increased ICP. An inadequate supply of oxygen can lead to increased ICP, so you may be given oxygen.
An electrocardiogram is used to monitor your current cardiac status and to determine if any cardiac conditions that might predispose to stroke are present (such as atrial fibrillation/flutter or an signs of an old heart attack).
Through blood tests, the doctor will also assess your hemoglobin level (to rule out anemia), platelets and clotting times (to assess your bleeding tendency), glucose levels, serum electrolytes, kidney function, oxygen saturation and carbon dioxide level.
You may be monitored for seizure activity and may be treated with a thrombolytic agent dependent upon the cause of your stroke and the time frame of the onset of your symptoms (see below for more detail).
Other diagnostic tests
A doctor may order certain diagnostic tests to confirm the stroke diagnosis, because other conditions such as complex migraines and transient ischemic attacks (TIAs) may produce symptoms similar to a stroke.
A CAT scan (computerized axial tomography) of the head is usually ordered to identify the type of stroke that has occurred. The technique creates an image of the brain using X-rays. It also can rule out the presence of a tumor, abscess or intracranial hemorrhage.
An MRI (magnetic resonance imaging) provides accurate images of the brain using energy waves and determines the presence, location and size of aneurysms. An MRI provides a better visual image of the brain stem and related structures than a CAT scan. It also shows evidence of an ischemic stroke more quickly than does CAT scan. However, CAT scans have the advantage over MRI because they can be performed more quickly, are less expensive, are more readily available at most hospitals, and better show acute bleeding.
Other tests may include:
DSA (digital subtraction angiography).
A trancranial and/or carotid doppler ultrasound test.
Your doctor may order an echocardiogram if he or she suspects a cardiac embolus. Echocardiograms are similar to the doppler ultrasound test noted above, however, use ultrasonic waves to provide a visual picture of the heart rather than the blood vessels supplying the brain.
Alteplase (a tissue plasminogen activator, or t-PA) is an intravenous thrombolytic enzyme (a compound that breaks up or dissolves a clot) used to treat acute ischemic stroke. Even today, it remains the only FDA-approved agent proven to be effective in treating acute ischemic stroke. While t-PA lessens the overall decrease in functional abilities associated with stroke, it is only effective if given within three hours since the true onset of symptoms and when hemorrhage has been ruled out as the stroke's cause. The time frame limiting t-PA's use reaffirms the necessity for the urgent seeking of emergency care when stroke symptoms begin. The mechanism of t-PA's action is that it causes breakdown in fibrin, a component of blood clots. While the benefits of thrombolytic therapy clearly exceed its costs when given within 3 hours of symptom-onset, thrombolytics can lead to life-threatening adverse reactions including cerebral hemorrhage, arrhythmias, spontaneous bleeding, cholesterol embolization and anaphylaxis (an immediate allergic response). Patients are monitored very closely during the administration of this therapy.
In circumstances whereby the cause of stroke is thought due to an embolus (e.g. from the heart), anticoagulation with intravenous heparin may be given. Heparin alters the clotting process, helping to break down existing clots and prevent the formation of new ones. Like t-PA, heparin is contraindicated in those patients who have had a hemorrhagic stroke. Warfarin (or coumadin) is an oral anticoagulant frequently prescribed over the long-term for patients who have had or are at high risk of experiencing an embolic stroke.
Finally, aspirin therapy while it is effective for treating the acute symptoms of a heart attack is not advocated for home use at the time of onset of stroke symptoms. This is because aspirin may be harmful if the stroke is hemorrhagic rather than thrombotic. Aspirin may be prescribed after a doctor has carefully evaluated your condition. Clopidogrel (or Plavix) is a medication like aspirin that also inhibits platelet function and may be prescribed with aspirin for the prevention of recurrent strokes.
Urgent neurological surgery at the time of a stroke (hemorrhagic) presentation is usually reserved for the evacuation of blood in the brain and repair of the ruptured vessel.
Carotid endarterectomy (removal of blood clots from the carotid arteries feeding the brain) is performed to prevent first time or recurrent thromboembolic strokes in patients found to have severe carotid artery narrowing.
Carotid angioplasty is a relatively new procedure becoming increasingly more popular that, like percutaneous coronary interventions, uses a catheter-guided balloon and/or stent to open up a blocked carotid artery.
As you sit in the hospital waiting room, you might wonder what put your brother at risk for a stroke, and what preventative measures can avoid this life-threatening event. The National Stroke Association (NSA) and the American Heart Association (AHA) list the following as risk factors for stroke:
- Heredity. The risk for stroke increases if you have an immediate family member who has had a stroke. The risk for subarachnoid hemorrhage (SAH) increases when two or more direct family members (parents, siblings) also have had a SAH.
Age. The risk for stroke increases with age. Approximately 5 percent of the population over age 65 have had at least one stroke. The risk doubles every 10 years after the age of 55. SAH occurs most frequently in middle-aged people, most commonly between the ages of 40 and 60. Intracerebral hemorrhage (ICH) typically does not occur under the age of 45, however, the risk doubles for every 10 years after age 45.
Gender. Men are at a higher risk for stroke over women for most types of stroke with the exception of the SAH. Women are affected in 60 percent of the cases of SAH.
Hypertension. Elevated blood pressure is the most significant risk factor for stroke that can be controlled - approximately 70 percent of all stroke victims have hypertension.
History of prior stroke. A person who has had a stroke is more likely to have a second stroke than someone who has never had a stroke.
Heart disease and carotid artery disease. The presence of heart disease doubles the risk for stroke. Atrial fibrillation (an irregular and ineffective heart beat) and atherosclerosis (a process that causes the build-up of fatty deposits in the artery walls) both increase the risk for stroke. Atrial fibrillation is a frequent cause of embolic strokes because it promotes clot formation within the left atria of the heart which may subsequently break off and travel to a blood vessel in the brain. Atrial fibrillation is most commonly diagnosed with an ECG.
Secondary risk factors such as elevated cholesterol, obesity and a sedentary lifestyle subsequently increase the risk for stroke.
Diabetes. Particularly type 2 diabetes is an important stroke risk factor. Its common association with hypertension, elevated cholesterol levels, and obesity further compounds the risk.
Cigarette smoking. Cigarette smoking increases the risk for stroke in several ways. It constricts blood vessels, elevates blood pressure, and is a noted risk factor for heart disease. Women who take oral contraceptives and smoke increase their risk for stroke.
Hyperviscosity syndromes. Hyperviscosity refers to very thick blood and is usually caused by a number of serious blood disorders (e.g. multiple myeloma, polycythemia vera). Thicker blood has a greater tendency to clot, thereby increasing the risk for stroke.
Alcohol and substance abuse. Alcohol and substance abuse can increase the risk for ICH. According to the NSA, consuming more than three alcoholic beverages per day can raise the risk of ICH by seven times. Alcohol also increases the risk for SAH and ruptured aneurysms. The majority of ICH cases (85 percent to 90 percent) that occur in people in their 20s and 30s are associated with substance abuse.
Anticoagulant medications. Anticoagulants, usually used for certain heart conditions (e.g. atrial fibrillation, mechanical heart valves, severe heart failure) and preventing future ischemic strokes, thin the blood and decrease blood clot formation. Anticoagulants can be a risk factor for ICH if the blood becomes too thin. All patients on anticoagulants should regularly have their blood drug levels checked by a member of their health care team.
Geographic location and climate. Strokes seem to occur more frequently in the "stroke belt" - an area in the southeastern United States. And death from stroke occurs more frequently during intensely hot and cold temperatures.
The Prevention Advisory Board of the NSA has presented the following stroke prevention guidelines to help guide the public in the prevention of stroke:
- Blood pressure. Because hypertension is a leading cause of stroke, you should know and understand your blood pressure readings. Your blood pressure is elevated if the reading is consistently greater than 140/90 mmHg. Diet, medication and lifestyle changes can help control hypertension.
Smoking cessation. There are many programs and medications available to help you quit smoking.
Alcohol consumption. Studies have shown that drinking up to two glasses of alcohol per day may decrease the risk of stroke by half. But if you do not already consume alcohol, physicians do not recommend that you start.
Cholesterol levels. You can control and treat high cholesterol with diet, exercise and medications.
Diabetes. Diet, exercise and medication can control diabetes and prevent many of its unfortunate complications.
Exercise. Daily exercise improves your health and lowers the risk for many disease processes. Consult your physician for an appropriate exercise plan.
Healthy diet. Healthy eating contributes to a healthy lifestyle. A diet that is low in sodium and fat reduces the risk for stroke.
Circulation problems. Treating circulation problems can decrease the risk for stroke. Medication and lifestyle changes are paramount in the treatment of circulatory disorders.
Know the symptoms for stroke. If you experience any symptoms of stroke (see symptoms listed in Part 1) call 911 and get help. Any type of stroke is considered a medical emergency - remember that immediate treatment can make a difference between life and death.
Rehabilitation begins almost immediately after a stroke and is initiated in the hospital. The severity and extent of damage incurred by a stroke strongly influence the prognosis of recovery and determines the setting for rehabilitation. While acute, subacute, or rehabilitation units in the hospital are usually initially considered, it is important to ask your physician about special rehabilitation hospitals, home care therapy, outpatient therapy and long-term care facilities that provide skilled nursing care and therapy as appropriate. Physical, occupational and speech therapy play an important role in the rehabilitation process. Effective rehabilitation is one of the most important vehicles to help you regain as much functional independence as possible.
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