Alzheimer's Disease Medical Tests & Diagnosis Methods, Tools

Conditions & Diseases: Brain & Nervous System

Alzheimer's Disease

Medical Tests & Diagnosis Methods/Tools

There are no specific tests to diagnose Alzheimer’s disease thus the process of diagnosing the disease involves exclusion - ruling out the “...other diseases and conditions that can cause memory loss." In order to differentiate AD from other causes of memory loss, the following aspects are taken into consideration:

Medical History:
The doctors will enquire about the individual’s general health and past medical history to know and understand if the individual is facing any difficulty in performing his/her routine activities. In the process, the doctor may discuss with his or her family, friends and colleagues to collect more information (13).

Basic Medical Tests:
Routine basic diagnostic tests such as blood tests, thyroid and liver function tests, glucose tests etc., indicating illnesses are conducted to rule out other diseases. Depression screening may also be conducted and at times a spinal fluid collected for testing (14).

In addition, the doctor would also inquire about diet, nutrition and consumption of alcohol. The doctor will also review all the patient's medications including over-the-counter drugs and supplements. The doctor would try to identify other disorders that can cause loss of memory, confusion, attention deficit or symptoms similar to dementia that include:

Anemia, malnutrition or vitamin deficiencies
Excess consumption of alcohol
Side effects of medication
Diabetes
Kidney or liver disease
Thyroid abnormalities
Problems with the heart, lung or blood vessels (15)

Mini-Mental State Exam (MMSE):
This is one of the most common tests used to “assess mental function” of the patient. It involves various questions typically framed to examine the mental skills required to perform day-to-day routine activities. The questions may be as follows:

To remember and recall the names of three common objects such as lock, pen and penny after a few minutes.
To state the current date, day of the week, year and season.
Count backwards from 100 by 7s or spell a word backwards.
Name a couple of familiar objects that the doctor points out.
Tell a common proverb or saying after the examiner.

Various other such questions are posed and the results evaluated. A maximum score of 30 MMSE points are taken for consideration. A score of 20-24 suggest mild dementia, 13-20 suggest moderate dementia and below 12 indicates severe dementia. On an average, the score declines by 2-4 points every year for a person suffering from AD (15).

Mini-Cog Test:
A smaple of a "Mini-cog" test (cog = cognition) involves the following two types of tests:

1. Remembering and repeating the names of three common objects.
2. Drawing a clock and showing 12 numbers in their places and time asked for by the examiner (15).

Neurological Exam:
This is an important test to assess the proper functioning of nervous system as a whole and the brain in particular to identify disorders, if any, other than Alzheimer’s disease. The physician may test for reflexes, coordination and balance, muscle tone and strength, eye movement, speech and sensation (15).

Brain Imaging:

Structural Imaging: This technique furnishes information such as shape, position or volume of brain tissue. These techniques include magnetic resonance imaging (MRI) and computed tomography (CT).
Functional Imaging: This technique reveals the working of cells in various regions of brain by “...showing how actively the cells use sugar or oxygen.” The techniques include positron emission tomography (PET) and functional MRI (fMRI) (15).

Article by Kona Vishnu, MS
Medical Writer,
OmniMedicalSearch.com