What Tests Are Commonly Used To Diagnose Dementia?

Medically reviewed by Majesty Purvis, LCMHC
Updated October 9, 2024by BetterHelp Editorial Team

If you or a loved one demonstrate symptoms of dementia, you may start to have questions about the diagnostic process. What tests are used to diagnose dementia? How accurate are diagnostic tests? Do misdiagnoses ever occur? In this post, we explain more about dementia testing. Though there is no single test to diagnose dementia, multiple medical tests and evaluations are used to make a diagnosis and determine appropriate treatment for a person’s symptoms. An early diagnosis can help people living with dementia and their caretakers prepare for the future and manage health care appropriately.

You deserve to have support through this time

Getting your medical history

Before you start the dementia testing process, the doctor doing the testing will likely want to know more about your history. You can answer these personal history questions alone, but it's recommended you bring a loved one to ensure you don't leave out any critical details.

First, the doctor will ask about your symptoms. For example, you'll be asked to report what symptoms you have, when they started, and if they are hindering your day-to-day life. They may also ask if certain situations, tasks, or medications worsen symptoms. The doctor will then look at your general health and screen for other disorders. Sometimes other medical conditions can cause symptoms similar to dementia, such as brain tumors. In these situations, symptoms like memory problems or challenges with thinking skills may be reversed if the underlying condition is treated. The doctor will also look into what medications you are taking. Sometimes, dementia-like symptoms may be a side effect of medications.

Some health professionals ask more detailed history questions. For example, you may be asked about your health history and illnesses other family members have had. These history questions are meant to rule out any other possible causes of your symptoms. Certain forms of dementia (e.g., Alzheimer’s disease) tend to accumulate in families, while others (e.g., Creutzfeldt-Jakob disease, normal pressure hydrocephalus) have weaker genetic components. A discussion of familial risk factors can help a professional better understand the likelihood of an individual having a specific neurodegenerative disorder. Once these questions are completed, dementia test diagnoses will begin.

Physical assessments

Dementia affects mental abilities, but a person with dementia may also show physical signs of the disease. For example, people with various forms of dementia—including normal pressure hydrocephalus, frontotemporal dementia, and Creutzfeldt-Jakob disease—can struggle with balance and experience other movement challenges. Your doctor may perform physical tests as part of the diagnosis. In addition to general evaluation procedures such as checking your blood pressure and pulse, here are a few physical tests the doctor may perform.

  • Reflex tests: Dementia patients may have poor reflexes.

  • Muscle assessments: If the patient is in good physical shape, yet their muscles are weakening, this may be a sign of dementia.

  • Hearing and vision tests: Dementia can impair these two senses, and tests can show if there has been a sudden, unexplained loss of hearing or vision.

  • Walking assessments: They may look at your coordination and balance as you walk across the room, and check your spinal cord alignment. If you seem unbalanced or have trouble walking, this may be a sign of dementia.

Physical exams are effective because the doctor will likely have your past physical exam records on hand, and they can compare your new results to those from the last time you were there. If there are any unusual changes found during a physical exam, you may need other assessments before a diagnosis can be given. However, some early stages of dementia may not show any noticeable physical changes. Physical exams are just one part of the early detection process, and they can help identify any other diseases present.

Cognitive assessments

A major part of a dementia diagnosis is testing mental capabilities. Dementia affects thinking and memory, and these tests evaluate any deficiencies in those areas. Mental capabilities tests may feel like taking a quiz in school. You'll have a pen and paper, and you'll receive a score at the end.

These types of tests may include a variety of different question types, including:

  • Short and long-term memory questions: Some patients with dementia may remember their childhood, but can't remember what they had for breakfast that morning, or vice versa.

  • Concentration questions: Dementia may affect your ability to focus on particular objects or reduce your attention span.

  • Communication assessment questions. Those affected by dementia may not be able to communicate as well as they'd like.

  • Awareness questions: People with dementia may lack awareness of aspects of the outer world, such as what city they are located in, or what month or season it is.

These tests cannot perfectly identify dementia since other factors, such as education level, can impact scores. For example, some people who lack education may do poorly on these types of tests but not have dementia. That's why these tests aren't used to diagnose on their own but are used in tandem with other types of assessments.

Laboratory assessments

People suspected of having dementia usually have their blood drawn. Health care providers may request several blood samples to check for other potential causes of your symptoms. For example, blood tests may check your liver, kidneys, and thyroid, look for diabetes, or analyze vitamin B12 and folate levels. If they find something unusual in your blood tests, they will pursue that and see if it is the reason for your dementia. Otherwise, you may need further tests. Other tests may include a cerebrospinal analysis, which can detect the presence of proteins that cause disorders like Creutzfeldt-Jakob disease and Alzheimer’s; a toxicology screen, to assess drug and alcohol use; or a urinalysis, which research shows could reveal biomarkers for dementia

Brain scans

Once simpler tests have ruled out other factors, your doctor may request a brain scan. Sometimes, simpler tests can be used to diagnose dementia, but if you've done different tests and have not gotten definitive results, a brain scan may be necessary. Types of scans used to screen for dementia include computerized tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET).

Though they can detect significant brain changes, brain scans don’t always provide definitive answers. These scans are one of many useful tools that can help doctors diagnose Alzheimer’s disease and other dementias. Brain scans can also rule out other factors, like a stroke or brain tumor.

A brain scan can also help identify what type of dementia you have. Different forms of dementia affect different brain regions. Frontotemporal dementia, as its name suggests, typically leads to degeneration in the frontal and temporal lobes; Alzheimer’s disease causes damage to the hippocampus, cerebral cortex, and amygdala; and normal pressure hydrocephalus occurs to due pressure from excess cerebrospinal fluid in the brain’s ventricles. 

The focus of degeneration can also depend on the stage of dementia an individual is experiencing. During the later stages of Alzheimer’s disease, cortical damage is common. Early Alzheimer’s, however, often involves degeneration of the hippocampus, then the amygdala. 

However, the scan may not show any unusual activity in the brain if a person is only in the early stages of the disease. In cases like these, more scans or tests may be required. Your doctor may perform brain scans that look at blood flow and see if there is anything unusual. EEG testing can look at brain activity and rule out epilepsy as the cause of symptoms. 

Genetic evaluation

Doctors don't always order genetic testing, but this type of testing can help determine if you have genes that put you at an increased risk for certain types of dementia. Younger adults may seek the expertise of a genetic counselor to understand whether they are likely to develop dementia in their older years.

The future of testing for a more accurate diagnosis

Medical technology has come a long way, and doctors have multiple tools available to help them make an accurate diagnosis. That said, there is still room for error, especially with a disease as complex as dementia. For Alzheimer's disease, it's speculated that as many as 20% of all cases are misdiagnosed. Sometimes, a patient with Alzheimer's may be misdiagnosed with depression or a different type of dementia.

New ways of diagnosing are continually being developed through clinical trials. Newer scan technologies can give more detailed images of the brain. Research on mental examinations helps refine practices to improve diagnostic accuracy.

If you believe you've been misdiagnosed with a type of dementia by your primary care doctor, it may be beneficial to get a second opinion from a specialist or other healthcare provider.

You deserve to have support through this time

Help is available for Alzheimer’s disease and other forms of dementia

Help is available for Alzheimer’s disease and other forms of dementia. In addition to a care plan to address a neurodegenerative disorder, individuals with dementia may benefit from joining support groups, where they can connect with people experiencing similar challenges. 

If you've been diagnosed with dementia, you may have many questions about your future and want to achieve your goals before further brain degeneration occurs. In cases like these, you can find peace of mind through mental health care. Counseling can help loved ones and caregivers of those with dementia, too.

Online therapy can provide many benefits to older adults with dementia or their loved ones and caregivers. You don’t have to worry about searching for a local therapist or remaining on a waiting list before talking to someone. When you sign up for online therapy, you’re matched with an available therapist who can start helping you right away. You can reach out 24/7, and they’ll get back to you as soon as they can. 

Online treatment has been thoroughly studied and found to be effective. A review of multiple research studies found that online therapy can help caregivers of people with dementia. Online treatments have helped improve well-being and reduce anxiety and depression among caregivers.

Takeaway

Getting a dementia diagnosis can be time-consuming and frustrating, and doing test after test can be stressful. If you need help coping with the process or have received a diagnosis and want to talk to someone, online therapy can help.
Navigate the challenges of dementia
The information on this page is not intended to be a substitution for diagnosis, treatment, or informed professional advice. You should not take any action or avoid taking any action without consulting with a qualified mental health professional. For more information, please read our terms of use.
Get the support you need from one of our therapistsGet started