Alzheimer’s disease can only be definitely diagnosed after death when an autopsy of the brain is performed. However, doctors use a variety of tests to make a probable diagnosis of Alzheimer’s.
Medical History and Physical Examination
The doctor will ask questions about the patient’s health history, including other medical conditions the patient has, recent or past illnesses, and progressive changes in mental function, behavior, or daily activities. The doctor will ask about use of prescription drugs (it is helpful to bring a complete list of the patient’s medications) and lifestyle factors, including diet and use of alcohol. The doctor will evaluate the patient’s hearing and vision, and check blood pressure and other physical signs. A neurological test will also be conducted to check reflexes, coordination, and eye movement.
Blood, urine, and possibly spinal fluid samples are collected. They can help the doctor evaluate other possible causes of dementia, such as thyroid imbalances or vitamin deficiencies.
A number of psychological tests are used to assess difficulties in attention, perception, memory, language, and problem-solving, social, and language skills. These tests can also be used to evaluate mood problems such as depression.
One commonly used test is the Mini-Mental State Exam (MMSE), which uses a series of questions and tasks to evaluate cognitive function. For example, the patient is given a series of words and asked to recall and repeat them a few minutes later. In the clock-drawing test, the patient is given a piece of paper with a circle on it and is asked to write the numbers in the face of a clock and then to show a specific time on the clock.
Imaging tests are useful for ruling out blood clots, tumors, or other structural abnormalities in the brain that may be causing signs of dementia. These tests include magnetic resonance imaging (MRI) or computed tomography (CT). Functional and volumetric MRIs, as well as positron-emission testing (PET) scans, have some ability to predict the future course of early Alzheimer disease. However, they are often not as good or no better than clinical exam and history in predicting the course of this disease
Review Date: 06/22/2010
Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.