How is Alzheimers disease diagnosed?
Alzheimers disease can only be conclusively diagnosed by examining the brain after death in an autopsy to determine the presence of characteristics plaques and tangles in certain brain areas. However, doctors can make a clinical diagnosis of possible or probable Alzheimers disease in a living person. Several tools are used to arrive at this diagnosis. These include: a complete medical history and tests that measure memory, problem solving, attention, counting, and language abilities. Medical tests such as analysis of blood are urine are used to determine if the dementia has another cause. Brain scans can be used to see whether the person has abnormalities such as strokes that could account for the dementia.
An early, accurate diagnosis of AD helps persons with AD and their families plan for the future. It gives them time to discuss care options while the patient can still take part in making decisions. Early diagnosis also offers the best chance to treat the symptoms of the disease. Today, the only definite way to diagnose AD is to find out whether there are plaques and tangles in brain tissue. To look at brain tissue, doctors must wait until they do an autopsy, which is an exam of the body done after a person dies. Therefore, doctors must make a diagnosis of “possible” or “probable” AD. Finding new and better ways to diagnose early AD is one area of current research. At specialized centers, doctors can diagnose AD correctly up to 90 percent of the time. Doctors use several tools to diagnose probable AD: • A complete medical history that includes information about the person’s general health, past medical problems, and any difficulties the person has carrying out daily activities. The doc
To check for the disease, your doctor will ask about your past health and do a physical exam. He or she may ask you to do some simple things that test your memory and other mental skills. Your doctor may also check how well you can do daily tasks. The exam usually includes blood tests to look for another cause of your problems. You may have tests to look at a picture of your brain, such as CT and MRI scans. By themselves, these tests can’t show for sure whether you have Alzheimer’s. But they may find small changes in the brain related to the disease.
Early diagnosis can improve the quality of life and may help resolve anxiety related to wondering what is wrong when the disease begins to interfere with an individual’s daily life. However, with the exception of an autopsy after death, no single test can determine whether an individual has Alzheimer’s disease. Diagnosis involves a complete physical and neurological examination, including laboratory tests, and a psychiatric assessment. The tests take more than one day and are usually performed on an outpatient basis. In addition to the individual for whom the diagnosis is being made, other family members may be interviewed in order to gather information about the patient’s behavior.
