NEW YORK — As we age, it’s not uncommon to have a brain fart here and there. But when does forgetfulness become more than just a mindless mistake? A simple memory test could pick up the early signs of Alzheimer’s disease well before symptoms start to show, scientists say.
Researchers report that having a poor score on the test may be linked to biomarkers in the brain connected with Alzheimer’s. The test could indicate the very early signs of memory impairment that precedes dementia by several years, research shows.
As part of the test, participants were shown pictures of items and given cues about its category, such as a picture of grapes with the prompt of “fruit.” They were then asked to remember the items, first on their own, then with the category cues for any items they did not remember. Half of the participants had no memory problems, while half had issues with either memory retrieval, the storage of memories or both, results show.
“These findings suggest that this test can be used to improve our ability to detect cognitive decline in the stage before people are diagnosed with Alzheimer’s disease,” says study author Ellen Grober, a professor at the Albert Einstein College of Medicine in New York, in a statement. “This could be helpful in determining who to enroll in clinical trials for prevention of cognitive decline. It could also help by narrowing down those who already have signs of Alzheimer’s in the brain with a simple test rather than expensive or invasive scans or lumbar punctures.”
How memory test could indicate Alzheimer’s disease
Grober says this type of “controlled learning” helps with the mild memory retrieval problems that occur in many healthy elderly people, but does not have much impact on memory for people with dementia.
The study uses data from 4,484 people with no cognitive problems and an average age of 71. Participants were divided into five groups based on their scores on the test, or stages zero through four. Stages zero through two reflect increasing difficulty with retrieving memories or items learned and precede dementia by five to eight years. In these stages, people have increasing trouble remembering the items on their own, but they continue to be able to remember items when given cues.
During the third and fourth stages, people cannot remember all of the items even after they are given cues. These stages precede dementia by one to three years.
“This system allows us to distinguish between the following: the difficulty people have retrieving memories when they are still able to create and store memories in their brains, which occurs in the very early stages before dementia can be diagnosed; and the memory storage problems that occur later in this predementia phase when people can no longer store the memories in their brains,” explains Grober.
Study participants also had brain scans to look for the beta-amyloid plaques in the brain that are markers of Alzheimer’s disease, as well as to measure the volume of areas of the brain associated with Alzheimer’s pathology. Researchers say that people who tested in the third and fourth stages were likely to have higher amounts of beta-amyloid in their brains than people in the lower stages. They were also more likely to have a lower volume in the hippocampus and other areas of the brain associated with Alzheimer’s pathology.
At stage zero, 30 percent of people had beta-amyloid plaques, compared to 31 percent at stage one, 35 percent at stage two, 40 percent at stage three and 44 percent at stage four.
Researchers say one limitation of the study is that the participants had a high level of education, so the results may not be applicable to the general population.
The study is published in the online issue of Neurology, the medical journal of the American Academy of Neurology. The study was supported by the National Institutes of Health, Alzheimer’s Association, Cure Alzheimer Fund and Leonard and Sylvia Marx Foundation using publicly available data from the A4 study.
South West News Service writer Chris Dyer contributed to this report.