Why Am I Experiencing Memory Loss Part 3: Diagnosing Dementia

In part one of this series, I discussed the difference between mild memory loss and dementia. In part two, I discussed the different signs, causes, and types of dementia. Now we turn to how dementia is actually diagnosed.

Diagnosing dementia and its subtype, or cause, is like putting together the pieces of a difficult puzzle. Some of the pieces can go in multiple spots and the pieces may all be similar in color or hue. Doctors can usually determine that a person has dementia with confidence. However, it is more difficult to pinpoint the exact type or cause of the dementia so that one would know if it is reversible or irreversible which, in turn, determines the treatment and care moving forward.

Scientific Definition of Dementia

Before we discuss the types of tests to determine the cause or type, let’s discuss the criteria that doctors use to determine a diagnosis of dementia in the first place. Doctors turn to the DSM or Diagnostic Statistical Manual for the definition and criteria to use. The fifth edition of this manual, DSM-5, defines dementia as a “major neurocognitive disorder.” To be considered a major neurocognitive disorder, there must be significant mental decline from previous mental performance on a variety of tests, or scoring below what is considered “normal cognitive function” for the general population. What do we mean by significant mental decline when it comes to diagnosing dementia?:

  • The mental decline must cause problems for the individual or interfere with their ability to complete essential everyday tasks by themselves.
  • The doctor must rule out delirium and other mental disorders such as depression. [i]

A diagnosis of dementia requires “significant mental decline” in at least two core mental functions. The core mental functions are:

  • Memory
  • Language skills
  • Ability to focus and pay attention
  • Reasoning and problem-solving
  • Visual perception

Core mental function abilities can be documented by the physician using screening tests such as the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA).

Tests to Define the Cause or Type of Dementia

As we discussed in the previous blogs, dementia is not a disease itself but a cluster of symptoms. These symptoms of dementia can be caused by a wide variety of conditions. Some are physical, some are mental, and may even include lifestyle factors. It is vital that any patient who may be suffering from dementia receive a comprehensive workup. There are four main categories of testing used to help determine the cause or type of dementia. They are:

  1. Mental and psychological
  2. Physical and laboratory
  3. Medical and lifestyle inventory
  4. Brain imaging

Once the dementia diagnosis has been determined it may be even more important to determine the cause or subtype because this will determine if it is reversible or irreversible and the steps moving forward for treatment and care.

Mental and Psychological Assessments

A psychologist or psychiatrist will examine a patient for any mental health conditions that could be causing the symptoms, which may include formal psychological testing. A mental health professional can determine whether chronic or severe depression is the main cause of the dementia. As previously mentioned, Depression is one of the most common causes of reversible dementia. Other mental health disorders such as Bipolar depression and schizophrenia can hinder brain functioning as well.

Physical and Laboratory Testing

A person with suspected or confirmed dementia should have blood tests to check their overall level of physical health. Simple blood tests can sometimes detect problems that can affect brain function, such as vitamin B1, B6 or B12 deficiency. The thyroid should be tested for proper functioning as well. A physician should also consider testing the spinal fluid for infection, inflammation, or markers of some degenerative diseases. Nutritional deficiencies can be treated, and in many cases, reverse the dementia symptoms.

Medical and Lifestyle Inventory

Doctors will also review current prescription and over-the-counter medications to see if what is currently being prescribed could cause the symptoms of dementia. They will also ask about lifestyle factors that can cause dementia such as a history of alcohol or other substance abuse. A healthy lifestyle with plenty of fresh fruit and vegetables along with moderate exercise can go a long way to help keeping dementia symptoms at bay.

Brain Imaging

Brain scans are often used for diagnosing dementia once other simpler tests have ruled out other problems. They are used to check for evidence of other possible problems that could explain a person’s symptoms, such as a multiple small strokes or a brain tumor. For instance, a “CT” scan can be used to check for signs of stroke or a brain tumor. An “MRI” can provide detailed information about the structure of the brain and if certain portions of the brain are shrinking. Finally, “PET” scans can show patterns of brain metabolism activity and if abnormal amyloid beta proteins, a classic sign of Alzheimer’s disease, have been deposited in the brain.

It is important when you notice signs of dementia, or are experiencing memory loss in yourself or a loved one – that a comprehensive work up and consideration of all the possible causes are taken into account. The underlying condition just might be reversible! Each person experiences dementia in a unique way. A skilled physician can correctly put the pieces of the puzzle together to form a clear picture of what is going on physically and mentally. Once the puzzle has been solved, a clear path forward can be mapped.

In Part 4 of our series, I will tell you about “Sharon,” and how we diagnosed and treated her memory loss.

[i] http://www.todaysgeriatricmedicine.com/archive/110612p12.shtml


A typical comprehensive workup to search for reversible as opposed to irreversible causes of dementia might include:

Formal cognitive testing by a licensed psychologist
 Thyroid status
 Vitamin B1, B6, B12 levels
 Vitamin D
 Folic Acid levels
 Quantitative CRP
 Lyme Screen and if positive, Western Blot testing
 RPR (followed by FTA if positive)
 Homocysteine level
 Comprehensive Metabolic Profile
 Complete Blood Count
 Erythrocyte (red blood cell) magnesium level
 Stool for ova and parasites (if history of diarrhea, fever or chills)
 MRI and MRA of the brain, to include hippocampal volume measurements
 Assessment for Major Depression (so-called pseudo-dementia of depression)
 Review of current prescription and over-the-counter medications (some cause the symptoms of dementia)
 History of alcohol or other substance abuse
 Neurology evaluation for other conditions (e.g. Parkinson’s disease, normal pressure hydrocephalus, tumor, etc).

If all of these tests/evaluations are negative, measures of amyloid beta in the brain (for example an Amyvid PET Scan). and cerebrospinal fluid amyloid and tau levels, can rule in/rule out Alzheimer’s disease.

For more information, including how you can order the Build Yourself a Healthier Brain mini-book, click here.

Potomac Psychiatry

A Tip to Untangle Your Brain™

Disclaimer ©2017 Untangle Your Life, LLC



Bruce Alan Kehr, M.D. is a National Award Winning Psychiatrist and author of Becoming Whole: A Healing Companion to Help Untangle Your Heart (get it here). Additionally, Dr. Kehr writes weekly tips to Untangle Your Heart™ and Untangle Your Brain™. He has served as Founder and President of Potomac Psychiatry since 1981. Washingtonian Magazine awarded him their “Top Doctor” designation from 2012 to 2017. In 2016 and 2017 the magazine named Potomac Psychiatry “The Face of Psychiatry” in their “Faces of Washington” issue. Dr. Kehr serves on the Board of the Institute on Aging of the University of Pennsylvania, and served as its Chairman from 2006 to 2009. The readers and editors of PharmaVOICE selected him as one of the “100 Most Inspiring and Influential Leaders in the Life Sciences Industry" in 2007.

visit http://drbrucekehr.com/