While there is still no cure for Alzheimer’s disease, early diagnosis offers many benefits. Johns Hopkins doctors review the current diagnostic tools available for dementia and Alzheimer’s disease.
If you’re worried about Alzheimer’s disease, the first step is to talk to your primary care physician about any symptoms you’ve been experiencing. Because diagnosing Alzheimer’s disease is primarily a process of elimination, your medical history and any recent health changes you’ve noticed might point to an explanation other than dementia. Your physician should screen you for depression, which can impair memory and cause anxiety, irritability, and poor concentration.
Your physician should also inquire about any medications and dietary supplements you are taking: Are you taking the proper dosage? Are you on the right schedule? Has another physician recently prescribed a new drug or changed your dosage? Again, medications can have effects that mimic those of Alzheimer’s disease, and this possibility must be ruled out.
The Mini-Mental State Exam and other tests for Alzheimer’s disease
If your physician suspects Alzheimer’s disease, he or she may perform a test called the Mini-Mental State Exam (MMSE), a 17-item screening test that assesses general cognitive function and provides a single numerical score. A score of 24 or higher is considered normal. The MMSE is not a particularly sensitive test for Alzheimer’s disease. Scores can drift up or down according to educational level, cultural background, reading level, and language skills.
Further testing may be needed at a separate office visit with a dementia specialist, such as a neurologist, geriatric psychiatrist, geriatrician, or neuropsychologist. The doctor will administer some tests by asking you questions; other tests require you to make drawings, solve special puzzles, or answer questions in written form.
Depending on your symptoms, your doctor may order laboratory tests. Again, the purpose is to rule out causes other than Alzheimer’s disease, tightening the circle of diagnosis until it zeroes in on the probable cause. Blood tests can identify anemia, liver disorders, thyroid problems, nutritional deficiencies, and infections.
In recent years, there has been a wave of news reports on the latest and greatest brain scanning techniques for the detection of early Alzheimer’s disease. These high-tech tests go by a variety of acronyms: MRI; fMRI; SPECT; PET; and CAT. Of the imaging tests mentioned above, your doctor is most likely to consider a CAT scan or MRI to check for physical brain abnormalities associated with Alzheimer’s disease, or to rule out some other cause of the symptoms. These brain scans may detect small strokes, which can cause problems in the brain’s blood supply and lead to vascular dementia. So-called functional scans, such as positron emission tomography (PET), are increasingly being used in the diagnosis of Alzheimer’s disease. They reveal information about the level of activity (function) in various areas of the brain that might be affected by Alzheimer’s disease.
Why Pursue Diagnosis?
When people notice mental slips and fear dementia, they may be reluctant to push for testing. There is, after all, no cure for Alzheimer’s disease. But a positive diagnosis, while frightening, offers some positive opportunities. Medications can slow the progression of the Alzheimer’s disease, giving you more time to enjoy with friends and family. If Alzheimer’s disease is caught early enough, it allows people to participate in their own healthcare decisions. Early diagnosis provides time to prepare psychologically, spiritually, and financially for the inevitable consequences of the disease. And it also gives a potential caregiver—typically a family member—more time to obtain the education and training needed to provide a dignified and healthy life for their loved one.
