Mini Guide to Cognitive Testing

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I continue to be surprised by how many people assume that they have Alzheimer's or dementia without having the proper diagnostic testing.  Additionally, many of my clients are confused as to what specific tests measure.

Unfortunately there is no one definitive test to diagnose Alzheimer's at this time. So I've put together this little “mini guide” of cognitive testing for this month's blog.

Here are some of the more well-known types of tests:


Cognitive Screeners:

Your doctor may conduct mental status tests in office to test your thinking and memory skills. Doctors use the scores on these tests to evaluate your degree of cognitive impairment. There are several different types of these tests, such as the Montreal Cognitive Assessment (MOCA), the Self-Administered Gerocognitive Exam (SAGE), and the Mini-Mental State Exam (MMSE).


What does it measure in terms of the brain? These quick screening tests do not diagnose any specific condition. The results will not tell you if you have Alzheimer's disease, mini-strokes or any number of other disorders. But the test scores can help your doctor know if further evaluation is necessary.


At the same time a word of caution: some people can get a perfect score on these tests because they can compensate, but they do still have a problem.  If you believe you are not where you should be cognitively, don’t ignore the warnings signs.  Perhaps the next step should be a neuropyschological test.

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Neuropyschological Testing:

While the screening tests may indicate there is an issue, they are not foolproof and can only identify at a high-level potential difficulties.

A neuropyschological test is much more in-depth and determines what areas are impaired.

A psychologists or neuropsychologists (psychologists with specialized training in brain disorders) may administer comprehensive neuropsychological tests, either as interviews or as paper-and-pencil tests. These tests, which take several hours, are used to identify what areas of cognitive function are impaired and what areas are still intact. They assess memory, reasoning, writing, vision-motor coordination, comprehension, and the ability to express ideas.[1]

What does it measure in terms of the brain? These tests help doctors determine if you have dementia, and if you're able to safely conduct daily tasks such as driving and managing your finances. They provide as much information on what you can still do as well as what you may have lost. These tests can also evaluate if depression may be causing your symptoms.[2]

CT Imaging of the head (also known as a CAT scan):

CT stands for computed tomography.  A CT image is taken using specialized x-ray equipment, which takes multiple pictures of the brain from different angles.  Contrast may be used.  Then the pictures are loaded into computer software to produce multiple images or pictures of the inside of the body.  A CT scan can produce cross-section images as well as 3D images. The results can be placed on a CD or DVD.

What does it measure in terms of the brain?   A CT scan looks at the anatomy of the brain. For instance, it can show a reduction in the size of the brain (atrophy), widened indentations in the tissues, and enlargement of the fluid-filled chambers called cerebral ventricles.[3]  A CT scan is generally used to rule out  tumors, strokes and subdural hematomas as possible causes of the Alzheimer's or dementia symptoms.



MRI (with Neuroreader):

An MRI or magnetic resonance imaging produces images of the brain using a powerful magnetic field, radio frequency pulses and a computer. It is able to produce images for soft tissue, bone and any internal organ.

An MRI can be run in and of itself or it can be done with Neuroreader software. "Neuroreader™ processes the MRI scans in around 10 minutes and provides a self-explanatory patient report with total brain volume, hippocampal volume and volumetric data on key segments of the brain measured against a healthy database."[4]  In essence, it gives you more detailed information about the structure and size of the brain.

But you can't do a regular MRI and then decide to use Neuroreader.  The MRI has to be taken at a facility that uses Neuroreader.


What does it measure in terms of the brain?  MRI's look at the anatomy, structure and size of the brain. Just like a CT scan it can be used to rule out other structural reasons for cognitive issues. For instance, MRIs can detect brain abnormalities associated with mild cognitive impairment (MCI) and can be used to predict which patients with MCI may eventually develop Alzheimer's disease.

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PET Scan: The positron emission tomography (PET) provides 3-D images of brain activity based on blood flow, oxygen consumption, or glucose use. [5]  While there are different types of PET scans, in general a PET scan uses a radioactive substance known as a tracer to detect substances in the body. 

There is a special type of PET scan that can show deposits of amyloid, a protein, in the brain and provides a high degree of confidence in the diagnosis.

What does it measure in terms of the brain? Unlike a MRI or CT scan, a PET scan can show how the brain is functioning.  MRIs and CT scans can only show the anatomical structure and volume. PET scans can be very useful  and show the difference in brain activity between a normal brain and one that is affected by Alzheimer's. It can also help differentiate Alzheimer's disease from other forms of dementia.[6]


SPECT scan:

A single Photon emission computed tomography scan (SPECT)  also uses a radioactive tracer to produce 3D images of the brain. The main difference between SPECT and PET scans is the type of radiotracers used. 

What does it measure in terms of the brain?

SPECT scan can show how blood flows to your heart or what areas of your brain are more active or less active. This is useful in evaluating specific brain functions. 

In addition to these cognitive tests, your doctor should take an extensive medical history, perform a physical exam and use lab tests to rule out other potential conditions.

Taken together, it can help track down an potential issue. The CT, MRI and PET scans can also help establish a baseline that you can use to determine whether you are making improvements.


I firmly believe in this case, the more information and data you have the better off you will be and be able to determine the next best steps and treatment plan for you.

Need help in navigating an Alzheimer’s diagnosis?  Contact me for a Free 15 minute consult to see how I can help you.
















Julie Kenney