Alzheimer’s disease can be diagnosed accurately only after death, by microscopic evaluation of the brain. Certain tests are used to distinguish Alzheimer’s disease from other causes of memory loss. These tests are described as follows:
The purpose of the blood test is to rule out other causes of dementia, such as thyroid disorders (underactive disorder) and vitamin deficiencies (such as a B12 deficiency).
A blood test is available for identifying which APOE alleles a person has. However, some researchers believe that Alzheimer’s Disease may never be predicted with 100% accuracy.
Currently, the APOE testing is used in research studies to identify those who have an increased risk of developing AD.
This method assesses thinking and memory skills and is used to diagnose Alzheimer’s disease and dementias at early stages. A commonly used exam is the Mini Mental Status Exam (MMSE)
Used to visibly diagnose clots, bleeding or tumor.
Magnetic Resonance Imaging (MRI)
MRI produces detailed images of the brain by using radio waves and a strong magnetic field. In AD research, it is used to create detailed maps of the brain, showing the size and anatomy of brain regions and structures. As AD progresses and neurons die, brain regions shrink and fluid-filled spaces called ventricles enlarge.
Computerized Tomography (CT)
CT uses X-rays from various angles, which is used by a computer to create cross-sectional images or slices of the brain.
Positron Emission Tomography (PET)
PET shows the areas of the brain that are not functioning properly, by detecting the levels of a radioactive material attached to a molecule and injected to the body. This radioactive materials travels via blood to areas becoming concentrated in the organs and tissues. The energy given off by this material is translated into pictures on a screen.
At present, reaserch is focusing on the development of radioactive substances that can bind to Beta-amyloid in the brain, having already discovered the Pittsburgh Compound (PiB), in 2004.
Functional Magnetic Resonance Imaging (fMRI)
This type of scan is used to measure brain activity during a cognitive task, such as remembering or learning.