Carole Rainey, whose name has been changed to protect her privacy, started to notice something wasn’t quite right with her husband, Bill, when he began to ramble in a way that was unlike him. He had just had his 80th birthday party, where some of the people closest to him also noticed a change in his behavior. Soon after, Carole took him to a teaching hospital to see a neurologist for an evaluation.
At that appointment, Bill was referred for a complete physical exam, blood testing, an MRI scan to rule out obvious causes for decline, such as a stroke or brain tumor, and many cognitive tests to assess his neurological function.
The cognitive tests showed abnormalities, but his daily functions were still relatively normal. His condition at that time, known as mild cognitive impairment (MCI), can sometimes progress to further cognitive decline.
Additional tests were conducted as part of his evaluation that showed the most likely cause for his MCI was the presence of abnormal proteins in the brain, signaling Alzheimer’s disease.
Bill’s condition progressed over the years, as is common with Alzheimer’s disease, and today the mild cognitive impairment has advanced to a stage of dementia in which cognitive impairment is severe enough to interfere with independent functioning. He sees a neurologist closer to home so that management recommendations can be adjusted as his disease progresses. With time, he’s become increasingly ill and difficult to manage.
“While he was still able, at the start of this journey, Bill and I sat down together to discuss how we wanted to handle our affairs so that when the time came that he was no longer able, Bill’s wishes and our finances would be in order,” Rainey says.
[READ Dementia Care: Tips for Home Caregivers]
What Is Dementia?
Dementia is a general term that describes a condition that can be observed in an individual. It is also a clinical symptom. It consists of the slow loss of a range of mental abilities, including memory recall, reasoning, thinking skills, language and problem-solving skills. It’s a change from a person’s typical level of cognitive functioning that is progressive and interferes with daily life. Like in Bill’s case, there can be years of milder symptoms before progression to dementia.
Alzheimer’s disease is the most common cause of dementia and accounts for about 50% of all dementia cases in people over the age of 65. However, there are many other causes of dementia, especially in people younger than 65 years old, when it is especially important to seek evaluation.
The prevalence of dementia increases with age, with about one-third of patients in their 80s being diagnosed with the disease. Contrary to popular belief, though, dementia is not a normal part of aging.
“Dementia doesn’t start overnight; rather, it progresses slowly until it seems that suddenly you can’t remember what happened yesterday,” says Sandra Weintraub, professor of psychiatry and behavioral sciences and the Alzheimer’s Center co-director at Northwestern Feinberg School of Medicine in Chicago. “It’s a very long process that usually isn’t detected until there’s a crisis.”
There is no cure for dementia and its effects can’t be reversed. Its progression, though, can be slowed down, which is why early detection is important. Currently there are clinical trials underway to find treatments and, ultimately, a cure for the causes of dementia.
[READ: Alzheimer’s Disease: Could Deep Brain Stimulation Help?]
Dementia Tests and Evaluation
There is no one test that can diagnose dementia. A good, comprehensive evaluation takes time, and you will need to see a specialist to be accurately assessed and diagnosed.
“Diagnosing dementia is often not straightforward because there are normal changes with the aging brain that may cause concern,” says Dr. Eileen Callahan, professor of geriatrics and palliative care at Icahn School of Medicine at Mount Sinai in New York.
In addition, she adds, other problems, such as depression, can mimic dementia.
When you or a family member begins to be aware of small behavioral cognitive changes, you should first make an appointment with your primary care physician. She can check your medical history and rule out problems like medication side effects, infections or electrolyte imbalances. After a couple of simple cognitive tests, you may be referred to a neurological specialist.
The following are the different components used to diagnose dementia by a specialist:
Medical history
The first thing a specialist will do is review your medical and psychological history. You should have a close family member or friend with you, who can also tell the doctor what they’ve observed.
Your doctor may be able to get an idea of what’s going on in your brain by reviewing your medical records and speaking to you and someone with you about the symptoms you or others have noticed. She’ll ask you about these symptoms: what they are, when they occur, when and how often they happen and if there have been changes in an activity that you were once able to do independently, such as paying bills or managing medication.
Some people naturally function at a higher level than others, so your doctor will need some parameters like your educational level to determine what behaviors are out of the ordinary for you. She will also want to know your family’s history and if there is any history of dementia or cognitive changes in your family.
“A great amount of time is needed to fully understand a patient’s story,” Callahan says, “and your medical history is the first step toward a diagnosis.”
Physical examination
During a workup for a diagnosis of dementia, a physical examination will measure your blood pressure, and blood tests will check the levels of chemicals, hormones and vitamins in your body.
The primary purpose of a physical exam is to check for underlying health conditions that could be causing cognitive problems. Some of the following problems may look like dementia:
— Untreated sleep apnea
— Thyroid problem
— Alcohol use disorder
Neurological exam
Before taking mental cognitive tests or having brain scans, a neurological exam that tests reflexes, coordination, strength, eye movement and speech will be administered to rule out causes other than dementia for cognitive decline. These tests can help rule out the following:
— Stroke
— Brain tumor
— Buildup of fluid on the brain
[READ: What to Do After Dementia Screening]
Mental cognitive tests
In the early stages of dementia, before you’ve been diagnosed, you can take some at-home tests that should be used only to tell you that you need further professional evaluation. These tests include some of the following:
— Self-Administered Gerocognitive Exam (SAGE). The SAGE can detect signs of early dementia by measuring cognitive functions like thinking and memory. There are four versions of the test that will ask you simple questions like today’s date or the answers to simple mathematical problems. It will take you about 13 minutes, and you should do the test alone. To get your score, you’ll need to consult with a doctor. Remember, though, that the results can only indicate that you may need to see a doctor for further evaluation.
— Mini-Mental State Examination (MMSE). You can take this test at home if you think you’re having cognitive issues. It takes about 5 to 10 minutes, should be interpreted by a doctor and consists of the following kinds of questions and tasks:
— Giving you a list of objects and asking you to repeat the list back later
— Copying a drawing
— Writing short, grammatically correct sentences
— Saying the day, date, month, season and year
— Mini-Cog. The Mini-Cog is a test that can be taken at home and is also often given and assessed by a doctor. First, you’re asked to say words, repeat them and recall them later. Then you’ll be asked to draw a clock and to make it show a specific time. If the clock isn’t finished in three minutes, you’ll be asked to repeat the words you were given at the beginning.
Other mental cognitive tests need to be administered by a team of specialists to measure your orientation, long and short-term memory, language skills, problem-solving skills, visual and spatial skills, concentration and other cognitive functions. Some of the tests are as follows:
— Montreal Cognitive Assessment (MoCA). The MoCA helps your team detect mild cognitive decline, early stages of dementia and can help identify people who may have Alzheimer’s disease. It can also detect cognitive decline due to conditions like stroke, frontotemporal dementia, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), depression and schizophrenia. The test consists of 30 exercises and tasks that take about 6 to 12 minutes.
— Abbreviated Mental Test (AMT). The AMT is used to assess the signs of dementia in elderly patients. It’s a quick test in which an assessment team will ask you 10 questions, such as your date of birth, address and who the current president of the country is.
— Alzheimer’s Disease Assessment Scale-Cognitive (ADAS-Cog). The ADAS-Cog assesses the degree of cognitive dysfunction in people with Alzheimer’s. It measures primarily language and memory, takes 30 minutes and consists of 11 tasks.
“It’s important to know a patient’s level of intelligence and what they are capable of when assessing the results of these tests, and then based on the patient’s background and level of education, we can determine if tests results are what would be expected of that individual,” says Weintraub.
Brain imaging scans
Brain scans are just one component of a whole assessment. If cognitive tests and assessments clearly indicate dementia, brain scans may not be necessary. Their primary use is to help rule out tumors, strokes, fluid on the brain or infarcts (areas of the brain that have died due to lack of blood supply). Some of the following imaging tests can be used during a dementia assessment:
— Computer tomography (CT) scan. A CT scan uses X-rays and computer technology to show detailed images of the body. It can detect signs of a stroke or brain tumor, but it won’t show detailed information on the structure of the brain. When diagnosing dementia, the CT scan is primary used to rule out other conditions that may look like dementia. It can also detect shrinkage of the cortex, the area of the brain that processes memory, attention and problem-solving.
— Magnetic resonance imaging (MRI) scan. An MRI uses magnetic fields and radio waves to provide detailed images to look for structural changes in the brain. Small lesions or changes in white matter may be an indication of small strokes or vascular disease. An MRI will also give you information about blood vessel damage that occurs with vascular dementia, but it won’t definitively tell you that you have dementia. Shrinkage in the frontal and temporal lobes of the brain may indicate dementia, and in early Alzheimer’s the frontal lobe is affected. Additionally, less volume in the hippocampus, the area of the brain involved in long- and short-term memory, can suggest early Alzheimer’s and be detected with an MRI.
— Positron emission tomography (PET) scan. A PET scan uses radiation to make images of brain activity, such as energy use or specific molecules in various brain regions. It can detect buildup of amyloid or tau protein, which are indicators of Alzheimer’s disease.
— Single photon emission computed tomography (SPECT) scan. A SPECT scan is a nuclear medicine tomographic imaging technique that can provide 3D images. It shows how the blood flows through the brain, which is useful in diagnosing dementia. Because dementia has a distinct blood flow pattern, a SPECT can differentiate between dementia and pseudodementia.
Biomarkers
Biomarkers are measurable indicators of what’s happening in your body. They can be found in blood, other bodily fluids, organs and tissues. When combined with other tests, biomarkers can help determine if you might have or be at risk for dementia. Again, these tests are only one part of a cognitive assessment. Some of the biomarkers that can detect dementia are as follows:
— Blood tests. Although not approved by the Food and Drug Administration, there are certain blood tests that can be used by doctors to detect amyloid changes in the brain or neural damage. These blood tests can measure the levels of beta-amyloid, a protein that accumulates abnormally in people with Alzheimer’s.
— Cerebrospinal fluid (CSF) test. Amyloid ratio tests approved by the FDA allow doctors to detect amyloid in the CSF that may predict amyloid changes in the brain. Neurofilament light increases the CSF of people with neurodegenerative disease and may show changes in the tau and beta-amyloid proteins.
Genetic tests
Researchers have found several genes that are linked to Alzheimer’s. Risk genes increase the likelihood of getting the disease and deterministic genes cause the disease. Inherited forms of dementia are very rare, so doctors usually don’t recommend testing for any of the known genes.
Bottom Line
Dementia typically appears slowly and gradually. Once there’s cause for concern by you or a family member, you should see a doctor sooner rather than later. With enough time, there are things you can do to optimize your cognitive function and slow down the progression of disease.
“If you know early, with the proper care and good planning, you can still have years of good living with mild cognitive impairment,” Weintraub says.
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Dementia Tests: What to Know and How They Work originally appeared on usnews.com
Correction 11/07/25: This story was published at an earlier date and has been updated with new information.
