Is There a Test for Dementia?
Unfortunately, the simple answer to this question is no, there isn’t a test for dementia. There isn’t a blood test like there is for diabetes, or a scan to look for specific changes in the brain like those that can be found in people who’ve had a stroke.
However, dementia can still be diagnosed reasonably accurately using a combination of clinical assessments, memory questionnaires, blood tests, and x-rays. While scientists continue beavering away to search for a more definitive test, these are the best available:
Clinical assessment: The doctor asks about the symptoms the person has noticed, the change and progression of these symptoms, and their affect. The doctor will also discuss family history of similar conditions, look at lifestyle factors like diet and smoking habits, and take account of other ongoing medical conditions and the effects of the pills used to treat them. It’s always helpful to have collateral evidence about the symptoms and their effects from a family member or friend.
Once the questioning is over, the doctor will carry out a top-to-toe physical examination to make sure the symptoms aren’t due to something else like a stroke, infection or brain tumour.
Memory questionnaires: These tests, which vary in complexity, use a variety of questions to tease out whether the person has problems with short- or long-term memory, calculations, finding words, planning, problem solving, and spatial awareness. This allows the clinician to work out whether dementia is indeed likely and, if so, which type it may be.
Laboratory tests: The doctor will request a battery of different tests to rule out other conditions that may cause similar symptoms of confusion and disorientation. These tests include checks for diabetes, thyroid problems, liver and kidney failure and infection. The doctor will also want to send a urine sample, again to rule out an infection and therefore a reversible cause of the symptoms.
Scans: Although no brain scan can yet say with a 100 percent certainty that a person has dementia and which type it is, a number of features in the brain can point toward a particular diagnosis. Part of the diagnostic process is therefore likely to involve referral for a brain scan such as a CT or MRI scan.
Once the results of each of these elements of the assessment are put together, the doctor will have a clearer idea about whether the person does or doesn’t have dementia. The doctor may also be able to confirm which type of dementia it is.