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What is dementia? The word refers to a mental decline in two or more core areas of brain function—including memory, judgment, communication, or language—that interferes with a person’s ability to function in daily life. Dementia can be caused by a number of different diseases ranging from Alzheimer’s disease (AD) to stroke to liver disease.
Diagnosing the cause of dementia is critical, because some forms—such as vitamin deficiency or thyroid-induced dementia—are reversible if treated. For those causes that are progressive and incurable, diagnosing the dementia as early as possible allows healthcare providers to initiate treatment of symptoms and allows caregivers to make the necessary plans for the future.
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What Is a Dementia Test?
The diagnosis of dementia is actually not made by one single test but rather by a combination of tests. This is why organizations such as the American Academy of Neurology and the Alzheimer’s Association recommend against individuals taking a dementia test online or a so-called Alzheimer’s test online.
Furthermore, a recent evaluation of many of the available dementia tests online by an expert panel of physicians, psychologists, and ethicists found them to be unreliable. Thorough evaluation for dementia involves performing a number of tests: medical and personal history, physical examination, neurocognitive testing, laboratory testing, depression screening, and neuroimaging.
- Medical and personal history: If you or your loved one is being evaluated for dementia, your healthcare provider will inquire about any medical conditions you have or medications you are taking. They will want to hear you describe the changes or problems that have prompted you to seek evaluation for dementia. Any family history of dementia will be especially important to share.
- Physical examination: A detailed physical examination, including a comprehensive neurologic examination, is a critical part of any dementia test. Specific neurologic deficits might suggest a particular cause of dementia such as a stroke or frontal lobe dementia (also called frontotemporal lobe dementia). Physical signs of thyroid disease or nutritional deficiencies might provide clues to metabolic causes of dementia.
- Neurocognitive testing: This part of the dementia test evaluation is what most people think of when they hear the term “dementia test” as it provides an assessment of the cognitive brain functions that can become impaired in dementia. The two general cognitive screening tests recommended by the American Academy of Neurology for use in detecting cognitive impairment are the Mini Mental Status Exam (MMSE) and the Memory Impairment Screen (MIS):
- Mini Mental Status Exam (MMSE): This test evaluates a range of cognitive functions including memory, concentration, communication and language, attention, ability to plan, and ability to comprehend instructions. Patients are asked to perform tasks such as writing a short grammatically correct sentence, memorizing a brief list of objects and then repeating it a little while later, and answering time-orientation questions. The maximum score you can achieve on the MMSE is 30 points. Scores of 20-24 are suggestive of mild dementia; scores of 13-20 are suggestive of moderate dementia; scores below 12 are suggestive of severe dementia.
- Memory Impairment Screen (MSI): The MIS, as the name applies, is a test designed for recent memory evaluation. Patients are shown a list of four words and are told that each word falls in a different category. They are then told a category cue (such as “game” for the word “checkers”) and asked to identify which word that category applies to. Inability to associate the words with category cues is suggestive of cognitive impairment. The patient is then distracted with other activities, including exercises such as counting backwards from 20, for two to three minutes before they are asked to recall the four words on the list they were originally shown. If they are not able to recall each word, they are then told the category cue to see whether it prompts word recall. The patient receives a score for each word (2 points for free recall; 1 point for cued recall; 0 points for no recall). A score of 5–8 suggests no impairment. A score of 4 or less suggests possible cognitive impairment.
Scores on either of these tests that are suggestive of cognitive impairment may prompt healthcare providers to order more in-depth neurocognitive testing (e.g. the Neurobehavioral Cognitive Status Examination, Kaplan Baycrest Neurocognitive Assessment).
- Laboratory testing: Laboratory testing to assess overall health and to look for possible metabolic causes of dementia are part of the dementia test evaluation. These laboratory tests include: a complete blood count, glucose level, thyroid function tests, electrolytes, blood urea nitrogen and creatinine levels, B12 level, and liver function tests.
- Depression screening: Symptoms of depression can overlap with those of dementia. These overlapping symptoms include memory problems and loss of interest in hobbies, social activities, and life in general. Assessing an individual’s mood or sense of well-being is therefore an important part of the general dementia screening process.
- Neuroimaging studies: Performing magnetic resonance imaging (MRI) or computed tomography (CT) studies to look for structural abnormalities that may be a cause for dementia is part of a standard dementia work-up. These tests can reveal evidence of stroke, tumors, or changes such as the brain atrophy (shrinkage) seen in frontal lobe dementia that can all be causes of dementia.
Originally published in June 2016 and updated.