In this Health Alert, Johns Hopkins doctors review simple, low-tech screening tests for measuring the decline cognitive health into dementia.
New developments in brain imaging technology are significant advances in Alzheimer’s research and diagnosis. But some decidedly low-tech screening tests may offer quick and inexpensive snapshots of a person’s cognitive health or level of dementia. Whether any of these tests are accurate enough to be used widely for screening remains to be seen, but one or several may be useful on an individual basis.
Dementia Test 1 -- Clock Drawing Test
The Clock Drawing Test is the most well known of the screening tests for dementia. Patients are asked to draw a clock with the hands pointing to a specified time: for example, 2:45. The most complete, well-organized, accurate, and spatially correct drawing is rated a "10,” and the least representative is rated a "1.” The more distorted and inaccurate the drawings, the more likely the person is to have dementia. (See illustrations at the bottom of this article.)
Dementia Test 2 -- Time and Change Test
This test measures the ability to tell time and perform a simple math task. In the time test, the patient is given 60 seconds to read the time on a clock and gets two attempts to get it right. In the change test, the patient is given three quarters, seven dimes, and seven nickels and asked to make change for a dollar. The change test has a three-minute limit, and two attempts are allowed.
Dementia Test 3 -- Sniff Test
Researchers have known for some time that loss of the sense of smell is an early warning sign of dementia, specifically Alzheimer’s. The beta-amyloid plaques that ultimately destroy memory and other cognitive abilities accumulate first in areas of the brain that are responsible for perception of odors. In a paper presented at a recent meeting of the American College of Neuropsychopharmacology, people with mild cognitive impairment were given a 10-item sniff test. The odors were lemon, strawberry, pineapple, lilac, clove, menthol, smoke, natural gas, soap, and leather. Study participants who misidentified more than two of the odors were five times more likely to progress to Alzheimer's disease than were those who performed better on the test.
Dementia Test 4 -- More Quick Tests
If dementia is suspected, doctors may give a person several tests that examine specific cognitive abilities. To test language ability, the patient will be asked to name as many items as possible in a given category, such as fruits or animals. Naming fewer than 10 items in one minute suggests slowed mental functioning. Counting backwards by sevens, spelling a word backwards and forwards, or listing the months of the year backwards are tests of working memory and attention. To test the ability to reason and plan, the doctor may ask the patient to describe similarities and differences between two items, such as an apple and an orange.
Listening to a list of words and reciting them back is a common memory test. A person without memory problems should be able to remember at least three words. Oftentimes, the person will be given a distracting task to complete before recalling the words. Someone who cannot remember at least two words out of three may have cognitive impairment.
Bottom line on dementia screening tests: It's important to realize that these are screening tests, not diagnostic tests. They are designed to be administered and interpreted by a healthcare professional. Poor results are an indication of probable cognitive impairment, but more sophisticated testing is necessary to make a diagnosis of Alzheimer’s disease.
