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Diagnosing Alzheimer's Disease


One should have a complete medical checkup based on specific markers for Alzheimer's disease, because sometimes what looks like Alzheimer's may actually be another treatable and curable ailment with similar symptoms. You should see a medical doctor, neurologist and/or other health professionals with an interest or specialty in Alzheimer's Disease. Choose someone familiar with the latest developments.


A doctor reviews test results.

The full Alzheimer's workup may include:

      • A complete physical
      • Psychiatric and neuropsychological testing
      • Blood work
      • Urinalysis
      • Chest x-ray
      • Electroencephalography (EEG)
      • Computerized tomography CT scan
      • Electrocardiogram (EKG)

This battery of testing is done to exclude all other conditions that present dementia-like symptoms. "Once all other identifiable conditions have been eliminated, a diagnosis will be given, usually phrased as 'a dementia of the Alzheimer's type,' often listed as DAT. The diagnosis is phrased this way because it is impossible to diagnose Alzheimer's diseasefor sure. It is often said that we can only establish its presence after death by an autopsy of the brain. The brain of a person who has died of Alzheimer's disease is said to be identifiable by the presence of plaques and tangles that show slow physical degeneration of the brain." (The Alzheimer's Sourcebook for Caregivers)


A medical doctor may order a CT scan or an MRI to eliminate strokes and tumors. A doctor may check the thyroid, folate, and B12 levels. A test for syphilis may be done and, for people at risk, an HIV test. Depending on the MD and the patient, a consultation to a neurologist or (if there is an indication) a psychiatrist may be ordered. If all signs point to dementing illness, a diagnosis will be established of possible AD. If the disease progresses over six months to a year and the repeat evaluation is negative (except for the mental status tests) a diagnosis of probable AD will be assigned.


If the MD does not provide the workup or refer you to a specialist, it might be best to seek a second opinion.

The Various Stages of Alzheimer's Disease (AD)

First Stage  Memory loss is the most notable at this stage. Intellectual capacity is often diminished to the extent that logical thought processes are affected. The individual may become unable to get through normal daily routines, have mood changes, and problems at work. Simple tasks like driving to the store become unfamiliar. The person may become reclusive or appear uninterested in activities.
Middle Stage As AD progresses to the middle stage, the symptoms are more obvious.
Memory loss and disorientation worsen, expressive and receptive language difficulties increase, and independence in activities of daily living is compromised. The patient’s ability to make autonomous healthcare and financial decisions is questionable, and others must assume the role of surrogate decision makers. At this point, difficulty with self-care tasks usually arises. This second stage shows exacerbated behaviors and conditions. There may be sleeping problems, agitation (sundowning), problems communicating, wandering, interference with motor skills, extreme and frequent mood changes, and a need for 24-hour supervision and care. This stage presents the most problem behaviors and can last 2-10 years.
Late Stage Late in AD, all cognitive functions are severely impaired and the person is completely dependent on others for most or all daily living activities. Even long-term memory is significantly compromised at this point. Individuals may misidentify familiar people, places, and objects. Constant supervision is required for the sake of safety and care. This stage shows a failure to thrive. The person may become bedridden and totally dependent, like a child. Not everyone gets to this stage, which can typically last from 1-3 years. 
Final Stage In the final stage of AD, there is little or no language, little purposeful movement, and total dependence on others. Death usually results from sepsis or pneumonia at this stage. At any point in the disease, co-existing medical problems can exacerbate symptoms and hasten decline if not properly treated. In the last stages, the concern should be the patient's comfort. 
  Source, including a more elaborate description and additional links.


Understanding the Diagnosis 

A diagnosis of Alzheimer's Disease usually falls into one of the following three categories:


  1. A diagnosis of probable Alzheimer's Disease indicates that the physician has ruled out all other disorders that may be causing dementia and has come to the conclusion that symptoms are most likely the result of Alzheimer's disease. 
  2. A diagnosis of possible Alzheimer's Disease indicates the presence of another disorder that may be affecting the known progression of Alzheimer's Disease, so that the process is somewhat different than what is normally seen.  In this case, however, Alzheimer's disease is still considered the primary cause of dementia symptoms. 
  3. A diagnosis of definite Alzheimer's requires examination of brain tissue and can be made only at the time of autopsy. Autopsy confirms the presence of plaques and tangles in the brain, which are the characteristic lesions of Alzheimer's, and is the only way to diagnose the disease with certainty.

Information Source

Last updated 09/09/14.