Testing and Diagnosis of Dementia

Article Highlights

This article will discuss the following topics:

PART I

• Quick summary
• Getting help from the Alzheimer’s Association
• Testing for dementia
• Other diagnostic assessments for dementia
• Medical history of the person with dementia
• Lab testing for Alzheimer’s and other types of dementia
• Brain imaging tests

PART II

• Other evaluations to detect dementia
• Pre-symptomatic testing
• Diagnosing dementia
• Specialists for diagnosing and treating dementia
• Final thoughts

Quick Summary

Diagnosing dementia and determining what type it is can be challenging. A dementia diagnosis requires that at least two core mental functions be impaired enough to interfere with daily living. They are:

• Memory
• Language skills
• Ability to focus and pay attention
• Ability to reason and problem-solve
• Visual perception

Your doctor will review your medical history and symptoms and conduct a physical examination. He or she will likely ask someone close to you about your symptoms as well. No single test can diagnose dementia, so doctors are likely to run a number of tests that can help rule out other problems. While physicians can almost always determine if a person has dementia, it may be difficult to determine the exact cause. Diagnosing dementia requires careful medical evaluation, including:

• A thorough medical history
• Mental status testing
• A physical and neurological exam
• Tests (such as blood tests and brain imaging) to rule out other causes of dementia-like symptoms

Getting Help From the Alzheimer’s Association

People with memory loss or other possible warning signs of dementia may find it hard to recognize they have a problem and may resist following up on their symptoms. A good place to start is reaching out to your local Alzheimer’s Association. The Alzheimer’s Association can provide a list of Alzheimer’s and dementia specialists in your area and Alzheimer’s Disease Centers (ADCs) that offer diagnosis and treatment services.

It is very important to seek help as soon as possible to get an early diagnosis of dementia. Although the disease cannot be stopped or reversed, an early diagnosis provides the individual and their family with more time to make plans for the future. Seeking help to determine if an individual has dementia will also give the person with dementia, as well as their family and other possible caregivers:

• Time to develop a relationship with the necessary doctors and care partners
• A better chance of benefiting from treatment
• An opportunity to participate in decisions about care
• And a better chance to coordinate issues such as transportation, living options, and financial and legal matters

Most people do not consider matters like this until it is too late, and they can find themselves overwhelmed with loose issues that they had not attended to. It serves one well to get ahead of a progressive disease like Alzheimer’s whenever circumstances permit a little planning. In addition, an early diagnosis is also important because people can benefit from care and support services, making it easier for them and their family to manage the disease. Alzheimer’s Navigator can help individuals identify their needs and create action plans. There are a variety of tests that an individual must undergo to determine if they have dementia and to rule out dementia-like symptoms. Thus, it is vital to see a specialist for testing so that the individual can receive the best diagnostic results.

Testing for Dementia

Doctors in most cases cannot test for dementia before the onset of signs and symptoms. A series of tests, evaluations, and screenings must therefore be conducted as soon as symptoms evolve to determine if an individual should receive a diagnosis of dementia.

Such cognitive screenings consist of the Montreal Cognitive Assessment (MoCA), Modified Mini-Mental State Exam (3MS or MMSE), and the Rowland Universal Dementia Assessment Scale (RUDAS). These specific assessments are all in relatively wide use for persons suspected of dementia or mild cognitive impairment (MCI), which is a condition in between age-related symptoms and those of dementia. These instruments have good psychometric properties and some advantages over the MMSE with respect to overcoming educational and cultural biases.

Other Diagnostic Assessments for Dementia

It should be understood that brief assessments, such as the ones already listed, go beyond assessing one’s memory and cognition. Depressed and anxious older adults often cite memory problems as a significant symptom, more so than younger populations. Brief screening tests such as the Geriatric Depression Scale (GDS), and the Geriatric Anxiety Inventory (GAI), are appropriate for older persons with suspected cognitive decline who can still manage self-report inventories. The Cornell Scale for Depression in Dementia, and the Rating Anxiety in Dementia scale, are both appropriate when self-reporting is no longer an option for the person with dementia, and when other informant reports on mood and anxiety may be required.

The MMSE assesses a number of different mental abilities, including short- and long-term memory, attention span, concentration, language and communication skills, ability to plan, and the ability to understand instructions. The MMSE consists of a series of exercises which include: memorizing a short list of objects and then repeating the list, writing a short sentence that is grammatically correct, such as “the dog sat on the floor”, correctly answering time-orientation questions, such as identifying the day of the week, and the date or the year. Although this is not a test to diagnose dementia, it is useful for assessing the level of mental impairment that a person with dementia may have. A perfect score on the MMSE is 30 points, and a score of 20-24 suggests mild dementia, 13-20 suggests moderate dementia, and less than 12 reflects severe dementia.

Medical History of the Person With Dementia

There are several diagnostic approaches that should be taken in conjunction with the many different assessments. For a start, a medical history is a necessity. During a medical history and physical exam, the doctor will ask the person and a close relative or partner about recent illnesses or other life events that could cause memory loss or other symptoms such as behavioral problems. A mental exam may also be conducted, involving such activities as having the person tell what day and year it is, repeat a series of words, draw a clock face, and count back from 100 by 7s (93, 86, etc., admittedly a tough process for anyone with multi-step cognitive difficulties.

Lab Testing for Alzheimer’s and Dementia

In addition to the above testing processes, multiple lab tests may be conducted to find if there are any treatable co-existing conditions. Simple blood tests can detect physical problems that can affect brain functions, such as vitamin B-12 deficiency, or an under-active thyroid gland. Sometimes the spinal fluid is examined for infection, inflammation, or markers of some other degenerative disease. Doctors may use a variety of laboratory tests to help diagnose dementia or rule out other conditions such as kidney failure, which can contribute to Alzheimer’s symptoms.

A partial list of these tests includes:

• A complete blood count (CBC) to look for infections
• Toxicology screenings which examine blood, urine, or hair to look for drugs that could be causing problems
• And a cerebrospinal fluid analysis to rule out specific infections that can affect the brain

Brain Imaging Tests

Brain Scans

Brain scans are often used for diagnosing dementia, though usually after other simpler tests have ruled out other possible co-existing conditions. Brain scans are needed to check for evidence of other problems that could explain a person’s symptoms, such as a prior major stroke, a tumor, and more.

CT Scan

A computerized tomography (CT) scan can also be used to check for signs of stroke or a brain tumor. However, unlike a magnetic resonance imaging (MRI) scan, a CT scan cannot provide detailed information about the structure of the brain.

MRI

An MRI can provide detailed information about the blood vessel damage that occurs in vascular dementia, plus any shrinking of the brain. Furthermore, in frontotemporal dementia, the frontal and temporal lobes are mainly affected by shrinkage.

PET Scans

PET scans show patterns of brain activity and can reveal if amyloid proteins have been deposited in the brain, which is a hallmark of Alzheimer’s disease.

EEG

Electroencephalograms (EEGs) may also be used by doctors to help examine people with suspected dementia. In an EEG, electrodes are placed on the scalp over several parts of the brain in order to detect and record patterns of electrical activity and to check for abnormalities. This electrical activity can indicate cognitive dysfunction in part or all of the brain. Many people with moderately severe to severe Alzheimer’s disease have abnormal EEGs. An EEG may also be used to detect seizures, which occur in about ten percent of people with Alzheimer’s disease. Doctors seldom use this test to diagnose dementia, but they may use it to distinguish dementia from delirium and to look for unusual brain activity found in Creutzfeldt-Jakob disease, a rare cause of dementia.

Other types of scans, such as a single photon-emission computed tomography (SPECT) scan or a positron emission tomography (PET) scan, may be recommended if the result of the CT or MRI scan is uncertain. These scans look at how the brain functions and can pick up abnormalities with the blood flow in the brain.

PART II

Other Evaluations to Detect Dementia

Doctors use evaluations such as a neurological evaluation to assess an individual’s memory, language, attention, problem-solving, visual perception balance, senses and reflexes. Doctors use cognitive and neuropsychological evaluations to assess language skills, math skills, memory, and other abilities related to mental functioning to help get an accurate diagnosis of a person’s condition. In addition, doctors may also use a psychiatric evaluation to determine if an individual is depressed or may be experiencing any other mental health conditions that may be contributing to the dementia-like symptoms.

Pre-symptomatic Testing

Testing people before symptoms begin in order to determine if they will develop dementia is in many cases not possible. However, in cases involving disorders such as Huntington’s disease, where a known gene defect is clearly linked to the risk of the disease, a genetic test can help identify people who are likely to develop the disease. Similarly, individuals can be tested for the ApoE4 gene, which is linked to greater risk of developing Alzheimer’s disease. Since this type of genetic information can be devastating, people should carefully consider whether they want to undergo such testing. Dementia researchers are also examining whether a series of simple cognitive tests, such as matching words with pictures, can predict who will develop dementia. One study suggested that a combination of a verbal learning test and an odor-identification test could help identify Alzheimer’s disease before symptoms become obvious. Other studies are looking at whether memory tests and brain scans can be useful indicators of future dementia. These efforts are currently in trial and error phases.

Diagnosing Dementia

The goal of a diagnosis is to eliminate any other possible condition that could be creating dementia-like symptoms. While screenings for cognitive and effective functioning serve a useful purpose when used as intended, these measures can be counter-productive when used as diagnostic tools or as a substitute for a complete clinical interview.

Doctors employ a number of strategies, such as the various above listed tests and evaluations, to diagnose dementia. The specific tests the healthcare provider recommends will be based on a number of factors, including what the physician found during the physical exam, and any possible discernible signs or other symptoms of dementia the person may be experiencing. Experts estimate a skilled physician can diagnose Alzheimer’s with more than 90 percent accuracy.

Alzheimer’s disease accounts for up to 80 percent of all dementia cases, and diagnosis may be complicated by other forms of dementia that have symptoms and pathologies similar to Alzheimer’s disease. Knowing the key features and pathology of Alzheimer’s and each other type of dementia can help in the accurate diagnosis of patients, so they can receive the treatment and support services appropriate for their condition and maintain the best possible quality of life. An accurate diagnosis of Alzheimer’s or another type of dementia also helps facilitate the planning tasks for the diagnosed person’s family and other caregivers and can provide some comfort to loved ones as an explanation for worrisome symptoms and behavior.

Specialists for Diagnosing and Treating Dementia

The first step in following up on symptoms is finding a doctor you or the caregiving member of the family feel comfortable with. Many people contact their regular primary care physician about their concerns regarding memory loss, for primary health care providers often oversee the diagnostic process themselves.

The best of all options, following a preliminary examination for dementia by the person’s immediate primary physician, would be for the person to be referred to a specialist who can follow up with an appropriate treatment strategy. The specialist doctor would be either a neurologist who specializes in diseases of the brain and nervous system, a psychologist with special training in testing memory and other mental functions, or a psychiatrist who specialize in disorders that affect mood or the way the mind works.

Although an interdisciplinary team may for any given reason not be available to an individual, it is always better to approach a dementia diagnosis and treatment with a team. With an interdisciplinary team, a dementia diagnosis and treatment is more likely to be accurate rather than relying on a single physician. An interdisciplinary team may include a neurologist, a psychiatrist, a psychologist, a geriatrician, i.e. a physician who specializes in working with older people, a neuropsychologist, i.e. a doctor who can perform testing to identify the nature and level of cognitive symptoms, and a social worker, i.e. a social services professional who can link individuals and families to community services. Together, such a team can identify the appropriate diagnosis and begin making the best suitable treatment decisions.

With an interdisciplinary team, a diagnostic workup can be completed efficiently and accurately. There are several components to a diagnostic workup. These components consist of:

• A medical history, which will help to identify other possible causes for dementia-like symptoms
• A medication history, which will help reveal a medication interaction or over-dosage that can account for confusion and other dementia-like symptoms
• A complete physical exam, which can detect acute or chronic medical conditions that might be causing confusion and other dementia-like symptoms
• A battery of laboratory tests that depend on the person’s medical history and current symptoms
• A neurological exam, which will help to detect nervous system problems that may be causing difficulties with thinking and behavior
• And a neuropsychological test, which can help establish the extent of the difficulties, track changes in the person’s cognitive abilities, and assess the person’s preserved abilities, which are all vital for proper treatment

Tests can help the doctor learn whether dementia is caused by a treatable condition. Even for those types of dementia that cannot be reversed, knowing the type of dementia a person has can help the doctor prescribe medicines or other treatments that may improve mood and behavior, and help the family members looking after the person, and hopefully provide long-term improvements in quality of life for all concerned.

Final Thoughts

Alzheimer’s and other types of dementia can be tough enough on everyone concerned without us having to brace the disease on our own and without proper help and guidance. The best course of action, at the first hint of cognitive difficulties, is to take your loved one to their primary physician with the plan to be referred to a specialist once the primary physician concurs with the likelihood, or even just a strong probability, of dementia. If it is a dementia diagnosis, the most important thing to remember is that you are not in this alone.

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