A simple test may predict a decline in memory and thinking long before symptoms appear, new research has suggested.
According to the study, the test may be able to identify the risk of developing cognitive impairment – which can be an early sign of Alzheimer’s disease – years later.
The study involved 969 people with an average age of 69 with no thinking or memory problems at the start of the study.
Study author Ellen Grober, of Albert Einstein College of Medicine New York, US, said: “There is increasing evidence that some people with no thinking and memory problems may actually have very subtle signs of early cognitive impairment.
“In our study, a sensitive and simple memory test predicted the risk of developing cognitive impairment in people who were otherwise considered to have normal cognition.”
The test included two phases.
For the study phase, people were shown four cards, each with drawings of four items, and asked to identify the item belonging to a particular category.
They would name the item “grapes” after being asked to identify a “fruit”.
In the test phase, people were first asked to recall the items – measuring their ability to retrieve information.
Then, for items they did not remember, they were given category cues, a process that measured memory storage.
People in the study were divided into five groups, or stages zero through four, based on their test scores.
Stage zero represented no memory problems while stages one and two reflected increasing difficulty with retrieving memories which can precede dementia by five to eight years.
Those in this group were able to remember items when given cues.
In the third and fourth stages, people could not remember all the items even after cues.
These stages precede dementia by one to three years, according to the scoring system which is used in Alzheimer’s disease testing.
A total of 47% of the people were in stage zero, 35% in stage one, 13% in stage two and 5% in stages three and four combined.
According to the research, 234 people involved in the study developed cognitive impairment.
After taking into consideration factors like age, sex and a gene that affects a person’s risk of Alzheimer’s disease, researchers found when compared to people who were at stage zero, people at stages one and two were twice as likely to develop cognitive impairment.
Those at stages three and four were three times as likely to develop cognitive impairment.
Prof Grober said: “Detecting cognitive impairment at its earliest stages is beneficial to researchers investigating treatments.
“It also could benefit those people who are found to be at increased risk by consulting with their physician and implementing interventions to promote healthy brain ageing.”
The findings are published in the Neurology journal.