Neuropsychological Testing for Alzheimer's
Often when a person goes to see a doctor because he or she has concerns about memory or the possibility of Alzheimer's disease, the doctor may recommend "Neuropsychological Testing." It is helpful to have some idea what this is, and what it is used for.
Neuropsychological testing is commonly performed by psychologists. However, other types of clinicians, most commonly educators, may also do the testing. The tests involve evaluations of thinking and memory. They have been designed to evaluate the functions involved in thinking and memory in such a way as to tell something about how the brain is working. This distinguishes these tests from "psychological tests" which are tests designed to measure behaviors, include thinking and memory, but are not designed to provide information about how the brain is working.
There are hundreds of neuropsychological tests, but in the setting of possible Alzheimer's disease there are only a few common test types.
First are the memory tests. These may be "verbal" memory tests or "nonverbal" memory tests. Verbal memory tests including trying to remember lists of words, the same as we all do when we are trying to remember a shopping list. They may also include trying to remember a brief story, the same as we all do when we are trying to remember a joke or a story that someone just told us. Nonverbal memory tests may include trying to remember a series of pictures or designs.
Very similar to memory tests are tests of orientation, such as the examiner asking where are we, what is the date and why are you here? Also similar to memory tests is the "digit span." This involves trying to immediately recall a list of numbers, the same as would occur when we try to immediately repeat a new phone number to someone after being told the number by the telephone operator.
The second most common group of tests are tests of language including reading, writing and, most importantly speech. Reading words is an ability that is rarely a problem in people with Alzheimer's disease and sometimes this is used as a way to estimate how well people with Alzheimer's disease would have performed on various tests before the disease began to disrupt their abilities. In contrast, a seemingly "easier" task, naming pictures, is commonly a problem in early Alzheimer's disease and therefore, picture or object naming is a common and useful neuropsychological test. Someone with Alzheimer's disease may be able to read aloud correctly the word "igloo" but be unable to remember and say the same word in response to being shown a picture of an igloo.
Another common group of tests are paper and pencil tests, including drawing a clock or copying designs. Also common are tests of attention and concentration plus decision-making and judgment. Depending on the circumstances other tests may be also used.
So, why is this testing performed? Does it "diagnose" Alzheimer's disease? The testing is performed to learn more about the patient. Although usually the patient and family can provide some description of the patient's ability to function and the doctor learns some additional information examining the patient, this is not always enough to tell the doctor all that is necessary to make a diagnosis or to fully understand the patient's strengths and weaknesses in thinking and memory.
Therefore, neuropsychological testing does not "diagnose" Alzheimer's disease. A diagnosis of Alzheimer's disease relies on all of the information about the patient that is related to their thinking and memory. The testing may be part of this information, but it should not be the only source of the information being used to make a diagnosis of Alzheimer's disease. In this way, Neuropsychological Testing is the same as any other testing, including blood testing and brain scan testing (such as MRIs and CAT scans). It is a tool to be used by the doctor to assist him or her in making the diagnosis about the presence or absence of Alzheimer's disease.