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What Medical Tests are Used to Diagnose Dementia?

close-up of form with dementia written on it

The U.S. population is aging. By 2040, about one in five people in America will be age 65 or older. As we age, it will become increasingly important to understand the challenges of diagnosing and caring for people with age-related dementia.

Dementia is not a disease but is considered a grouping of similar symptoms caused by other conditions and diseases that can impair individuals’ functioning.

According to the National Institute on Aging, such dementia symptoms include memory loss and confusion, difficulty reading and writing, getting lost in familiar surroundings, repeating questions, taking longer to complete daily tasks, acting impulsively, changes in personality, and difficulties with balance and other movements.

But how is dementia diagnosed?

Many underlying diseases and conditions can contribute to dementia. Some of the most frequent medical tests that are used to diagnose dementia are as follows:

A full examination

A medical professional’s thorough examination of the person is the best place to start. This will be the subject’s starting point to list their symptoms, learn if any specific conditions are causing the changes in functioning, and assess the person’s overall physical and mental health.

A full examination often begins with the doctor or primary care provider taking a full medical history and a physical examination. At this point, a neurological examination may also be performed to test a person’s balance, strength and coordination, and reflexes.

During a mental status examination, the subject will likely be asked questions about the day, date, time of day, and current events. Other questions might be used to assess their vocabulary and use of words, their ability to perform simple math calculations, and their ability to concentrate and remember lists of words or other information.

Medical tests

Laboratory tests, such as blood work, can be very helpful in an initial screening for dementia. Such blood tests can be used to detect health issues such as anemia (in which red blood cell counts are lower), thyroid problems (which can be one of the more reversible causes of dementia), liver and kidney problems, and vitamin deficiencies.

Blood tests might also be used to check for diseases such as HIV, syphilis, and Lyme.

In some cases, medical practitioners might use a lumbar puncture, also known as a spinal tap, to test the spinal fluid for infections in the central nervous system. Spinal fluid can also be tested for proteins that might indicate a person is suffering from Alzheimer’s disease. This procedure is a bit more complicated than a blood draw and will include a shot of anesthetic into the patient’s back before a needle is injected to retrieve a spinal fluid sample.

Other medical tests performed in order to understand a patient’s level of dementia might also include an EEG (an electroencephalogram) that shows the electrical activity in a patient’s brain, or an MRI or CT scan to help identify changes in the brain or to see evidence of any strokes that might have occurred, or to look for possible tumors.

Genetic testing

Genetics tests, the results of which are typically discussed with genetic counselors, might also be an important way to understand a patient’s physiology and dementia risks. New discoveries are constantly being made about which genes affect patients’ risks and outcomes with such diseases as Alzheimer’s or Parkinson’s disease. Genetic testing can often be performed after obtaining a blood sample or by swabbing tissue from inside a person’s cheek.

Psychosocial evaluations

Individuals being tested for dementia and other age-related diseases might also wish to undergo an evaluation that will help them understand their treatment and care options. A psychosocial evaluation, in which medical professionals and caregivers collaborate to understand a person’s current level of functioning and brainstorm ideas for a person’s future care, can be very useful.

Such a test, which often consists of questionnaires or medical checklists and a personal consultation or discussion with a health professional, can also help caregivers understand the extent of care that is necessary so they can begin to plan for their loved one’s future needs.

A number of tests and diagnostic tools can help patients and their loved ones better understand the nature of their dementia. Such tests can also be extremely helpful when deciding upon care and treatment plans for those individuals who need help in their daily functioning.


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