Friends and family of a person who starts showing early signs of Alzheimer's dementia tend to become aware of those signs earlier than traditional screening tests do, say researchers in an article published in the peer-reviewed medical journal Brain. An individual is usually evaluated by a healthcare professional with a range of cognitive tasks to gauge memory, such as comparing shapes or remembering a list of words or numbers.
Investigators at the Washington University School of Medicine in St. Louis developed a different way of testing somebody's memory and cognition - the two-minute Ascertain Dementia 8 questionnaire - it relies on somebody who knows the individual well, usually a friend or close relative. They call this person an informant, and he/she evaluates whether any alterations in the individual's cognition have undermined their ability to carry out everyday tasks.
The two-minute Ascertain Dementia 8 questionnaire (AD8) was validated by comparing its results with patients who were found to have biomarkers (biological indicators) for Alzheimer's disease, such as excessive levels of specific factors in the spinal fluid, or the detection of Alzheimer's plaques from brain scans. They found that the AD8 questionnaires matched the biomarker results better than the traditional screening tests did.
John C. Morris, MD, Director, the Charles F. and Joanne Knight Alzheimer's Disease Research Center, Washington University School of Medicine, said:
It's not economically feasible to screen everyone for Alzheimer's disease biomarkers. The AD8 gives us a brief and very low-cost alternative that takes a few minutes of the informant's time to screen for dementia and thus identify those individuals who need follow-up evaluations to determine if there truly are signs of Alzheimer's.
Traditional early-stage dementia screening procedures only give a snapshop, a slice of the individual's cognitive abilities at a specific moment - the moment they are being tested, Morris says. Asking the person being tested whether their mental abilities have altered in any way does not always provide accurate and reliable results, because the patient frequently lacks insight into his/her problem during the early stages of dementia.
With the AD8 questionnaire, the informant is asked to rate any changes they have noticed in the following areas:
- Have there been any problems with judgment? An example may be a bad financial decision.
- Has the individual's interest in hobbies or other activities diminished?
- Does the individual repeat things, such as stories, statements or questions?
- Does the person have problems learning how to use gadgets or appliances, such as the TV remote or a microwave oven?
- Has the person forgotten which month or year it is?
- Have you noticed any difficulty in his/her handling of complicated financial affairs, such as balancing a checkbook?
- Does he/she forget appointments more frequently than before?
- Have you noticed any consistent problems with memory or thinking?
People with regular exposure to the individual usually provide the best assessments, Morris said.
These informants can give us the retrospective perspective we need to know that a person's mental abilities have begun to meaningfully decline, indicating that additional testing is needed.
In this new study, the investigators:
- Collected 251 completed AD8 evaluations
- Tested the individuals using the Mini Mental State exam, a traditional dementia screening test
- Evaluated biomarkers for Alzheimer's in the patients, this included brain plaque scans and spinal fluid assays.
Based on our results, the AD8 appears to be superior to conventional testing in its ability to detect signs of early dementia. It can't tell us whether the dementia is caused by Alzheimer's or other disorders, but it lets us know when there's a need for more extensive evaluations to answer that question.
The AD8 is currently used in several countries - it has been translated into many languages, the authors wrote.
"Relationship of dementia screening tests with biomarkers of Alzheimer's disease"
James E. Galvin, Anne M. Fagan, David M. Holtzman, Mark A. Mintun, John C. Morris
Brain (2010) doi: 10.1093/brain/awq204
Written by Christian Nordqvist