The only test that can give a definitive diagnosis of Alzheimer’s disease is an autopsy with brain evaluation. An autopsy can reveal the plaques and tangles in the brain that are characteristic of Alzheimer’s disease. Nevertheless, an Alzheimer’s disease diagnosis is almost always possible using a few different tests.
According to the Mayo Foundation for Medical Education and Research, doctors today are able to diagnose Alzheimer’s disease with up to 90 percent accuracy. This is important, as there are many other disorders that can cause dementia. Doctors rely on a number of tests to accurately diagnose Alzheimer’s disease. These include:
- Brain imaging tests
- Lab tests
- Medical history
- Neuropsychological tests
- Physical examination.
Brain Imaging Tests
A brain scan (such as an MRI) is an important test in formulating an Alzheimer’s disease diagnosis. Imaging tests can reveal abnormalities in the brain that are characteristic of Alzheimer’s, such as areas of the brain that are dense (due to amyloid plaques) or uncharacteristically inactive.
Imaging tests can also reveal the presence of other potential causes of dementia, such as:
- Blood clots
- Brain tumors
Laboratory tests on blood and urine are also important for eliminating the possibility of the presence of other medical disorders. Lab tests can help to reveal the presence or absence of medical problems such as:
- Liver problems
- Thyroid disorders
- Vitamin deficiencies.
Medical and Family History of Alzheimer’s Disease
An examination of an individual’s personal and family medical history can offer some clues towards making an Alzheimer’s disease diagnosis. You may want to bring a friend or family member with you to help provide this information, in case you’re unable to provide all the necessary details.
The purpose of neuropsychological testing is to identify the cognitive symptoms of Alzheimer’s disease and to arrive at an accurate diagnosis of Alzheimer’s. Your doctor will use simple exercises and tests to assess your:
- Motor skills
- Problem-solving skills
- Visual-motor coordination.
Part of the process of coming up with a diagnosis for Alzheimer’s disease is to rule out all other potential causes of dementia. A physical examination can help accomplish this. Your doctor will look for any potential abnormalities in your nervous system or in any of your organs.
New Possibilities for an Alzheimer’s Disease Diagnosis: Neuroimaging
Neuroimaging is a relatively new and sophisticated type of imaging that enables doctors to measure changes in brain function or structure. These changes can be seen even in the very early stages of Alzheimer’s disease. This allows for an early diagnosis of Alzheimer’s disease, often even before symptoms of the disease have become obvious.
This promising new method of obtaining an Alzheimer’s disease diagnosis will allow those with Alzheimer’s disease to begin treatment much earlier than was previously possible. Although early treatment can not prevent the degenerative nature of Alzheimer’s disease, it can slow the process of mental deterioration.
Alzheimer Foundation of America. (n.d.) About Alzheimer’s: symptoms. Retrieved April 26, 2010, from http://www.alzfdn.org/AboutAlzheimers/symptoms.html.
Alzheimer Society of Canada. (n.d.) Finding out if it is Alzheimer disease. Retrieved April 26, 2010, from http://www.alzheimer.ca/english/disease/diagnosis.htm.
Fisher Center for Alzheimer’s Research Foundation. (n.d.) Alzheimer’s diagnosis importance. Retrieved April 26, 2010, from http://www.alzinfo.org/alzheimers-diagnosis.asp.
Mayo Clinic. (2009). Tests and diagnosis. Retrieved April 26, 2010, from http://www.mayoclinic.com/health/alzheimers-disease/DS00161/DSECTION=tests-and-diagnosis.
U.S. National Institutes of Health National Institute of Aging. (n.d.) Diagnosis. Retrieved April 26, 2010, from http://www.nia.nih.gov/Alzheimers/AlzheimersInformation/Diagnosis/.