This is the last in our series on stroke–and an important one. Thanks again to the American Heart Association and our experts for advise.
When someone has shown symptoms of a TIA or stroke, the first thing a doctor has to do is to make a diagnosis. A complete medical history is taken of both the event and a more complete medical history for diabetes, hypertension, heart and blood vessel disease and other neurological diseases. After listening to the heart, pulses, and bruits, a neurological exam to test the patient’s level of consciousness, orientation, memory, and emotional control will be done.
A doctor might use many different tests in a neurological exam. Some doctors test patients by having them stand motionless with feet together, arms outstretched and eyes closed; testing for facial paresis (paralysis) by having patients bare their gums and stick out their tongue. Hearing might be tested by rubbing the thumb and forefinger together about 12 inches from the ear.
Having patients read a newspaper using one eye at a time is a test for vision. Visual field can be tested having a person cover one eye and look into the doctor’s opposite eye. (The doctor will then bring a thumb or small object from the side and ask the patient to signal when it becomes visible.) The perception of pain and light touch, muscular strength and deep tendon reflexes are also commonly tested.
Identifying stroke warning signals is one way to diagnose a stroke. But proper diagnosis doesn’t stop there. Other tests may be run because the symptoms may not necessarily result from a stroke. For example, a brain tumor can produce similar symptoms.
A doctor must eliminate other possibilities before making a diagnosis. Remarkable advances in modern technology now make it possible to examine how the brain looks, functions, and gets its blood supply. These tests can outline the affected part of the brain and help define the problem created by the stroke. Most of the newer tests are safe and painless and can be undergone as an outpatient.
These tests fall into three categories: 1) Tests that image the brain make pictures that look similar to ordinary X-rays. 2) Tests that measure the electrical activity of the brain give useful information about how it functions and pinpoints areas of abnormality. 3) Finally, blood flow tests measure flow and detect blockages in blood vessels. They’re useful in revealing areas of significant atherosclerosis in carotid arteries. A doctor must decide on a case-by-case basis whether such tests will be useful, and if so, which ones to use.
The computerized axial tomographic scan (CT or CAT scan) may be the most well known imaging test, In computerized tomography, the person’s head is put in an apparatus resembling a beauty shop hair dryer and taped to avoid movement that might ruin the picture. CT scans take from 20 minutes to an hour to complete.
Magnetic resonance imaging scanning (MRI) is another imaging test. It uses a giant magnet to generate an image. MRI is similar to a CT scan but requires a different machine and takes longer. Radionuclide angiography (nuclear brain scan) is a third imaging test. In it radioactive compounds are injected into a vein in the arm, and a machine similar to a Geiger counter creates a map showing their uptake into different parts of the head. The pictures, rather then showing the brain’s structure, show how it functions. This test can detect blocked blood vessels and areas where the brain is damaged.
Two basic tests show the electrical activity of the brain: an electroencephalogram (EEG) and an evoked response test. In the EEG, small metal discs (electrodes)are put on the person’s scalp to pick up electrical impulses transmitted and received by the brain cells.
A machine equipped with pens transcribes this activity onto large pieces of paper. Evoked responses measure how the brain handles different sensory stimuli. They can detect abnormal areas of the brain. A doctor evokes a visual response by flashing light or a checkerboard pattern in front of a patient. For auditory evoked responses, a doctor makes a sound in one of the patient’s ears; for bodily evoked responses, one of the nerves in an arm or leg is electrically stimulated.
There are a variety of tests that measure blood flow. The Doppler ultrasound test is performed to detect blockages in the carotid artery. In it, a gel is put on the neck or eyelids, then a technologist puts a pencil-like probe into the gel and listens to blood flowing in the carotid artery.
In carotid photoangiography, a sensitive microphone is put on the neck over the carotid artery and a technologist listens for a bruit ( A bruit is the sound created by a turbulent blood flow as it passes through a partially blocked artery).
In ocular plethysmography (OPG), anesthetizing drops are put into the eyes, and then small plastic cups similar to contact lenses are positioned on the eyes to detect pulses or measure pressure in the eyes.
The cerebral blood flow test (inhalation method) measures how much oxygen dissolved in the blood supply reaches different areas of the brain. A person is told to lie flat on a table, then a cap containing detectors is secured over the head. The person starts breathing through a mask containing air mixed with a small amount of radioactive xenon. The test lasts 30 minutes to an hour.
Finally, digital subtraction angiography (DSA) gives an image of the major blood vessels to the brain. It lets the doctor know if there are any blockages, how severe they are, and what can be done about them. In this test, dye is injected into a vein on the arm, and an X-ray machine quickly takes a series of pictures of the head and neck.
Surgery, drugs, acute hospital care and rehabilitation are all accepted ways to treat stroke. When a neck artery has become blocked, surgery might be used to remove the buildup of atherosclerotic plaque. This is called endarterectomy. Drugs may be used when a blood vessel has been blocked or blood clots are a problem. They can help prevent new clots from forming or prevent existing clots from getting bigger.
Sometimes treating stroke means treating the heart because various forms of heart disease can contribute to a risk for stroke. For example, damaged heart valves may need to be surgically treated or treated with anti-clotting drugs to reduce the chance clots could travel to the brain and cause a stroke.
Beside being the third leading cause of death in the US, stroke is a major cause of serious disability. Many stroke victims are left with mental and physical disabilities, and receive expensive, time consuming and intensive rehabilitation to try to increase their independence. Spontaneous recovery in the first 30 days following a stroke probably accounts for most gains in functional ability. Still, rehabilitation is important.
To a large degree, successful rehabilitation depends on the extent of brain damage, the person’s attitude, the rehabilitation team’s skill, and the cooperation of family and friends. People with the least impairment are likely to benefit the most, but even when improvement is slight, rehabilitation may still mean the difference between staying in an institution and returning home.
The goal of rehab is to reduce dependence and improve physical ability. Often old skills have been lost and new ones need to be learned. Maintaining and improving a person’s physical condition whenever possible is also important. Rehab begins early as nurses and staff work to prevent such secondary complications as stiff joints, bedsores, and pneumonia. These can result from being confined to bed for long periods of time.
The role of the family during rehab is significant. A caring, able spouse can be one of the most important positive factors in rehab. It is important to educate family members as to the scope of dysfunction and damage caused by the stroke and how that person views the world. The family needs to know what to expect and how to handle the problems that will arise during the hospital stay and afterwards. For the stroke survivor, the goal of rehab is to become as independent as possible given the limitations resulting from the stroke.
Learning about the long term complications of diabetes is often trying, and many of us turn the page or tune out when confronted by information, but the facts given in these pages of our monthly magazine are for you and your family. They are shared with the best intentions so that if you need them they will be of help in prolonging life, making illness less frightening, and making you an informed consumer of medical care.
We all hope that all of us will never actually need to know about stroke, but if we do, we will know the questions to ask and be able to act in a responsible manner for our loved one and ourselves.