A three-minute brainwave test can detect memory problems linked to Alzheimer’s disease long before people are typically diagnosed, raising hopes that the approach could help identify those most likely to benefit from new drugs for the condition.
In a small trial, the test flagged specific memory issues in people with mild cognitive impairment, highlighting who was at greater risk of developing Alzheimer’s. Trials in larger groups are under way.
The Fastball test is a form of electroencephalogram (EEG) that uses small sensors on the scalp to record the brain’s electrical activity while people watch a stream of images on a screen. The test detects memory problems by analysing the brain’s automatic responses to images the person sees before the test.
“This shows us that our new passive measure of memory, which we’ve built specifically for Alzheimer’s disease diagnosis, can be sensitive to those individuals at very high risk but who are not yet diagnosed,” said Dr George Stothart, a cognitive neuroscientist at the University of Bath, where the test was developed.
The trial, run with the University of Bristol, involved 54 healthy adults and 52 patients with mild cognitive impairment (MCI). People with MCI have problems with memory, thinking or language, but these are not usually severe enough to prevent them doing their daily activities.
Before the test, volunteers were shown eight images and told to name them, but not specifically to remember them or look out for them in the test. The researchers then recorded the participants’ brain activity as they watched hundreds of images flash up on a screen. Each image appeared for a third of a second and every fifth picture was one of the eight they had seen before.
The scientists found that those with amnestic MCI, which largely affects a person’s memory for objects, had reduced responses to the test compared with healthy adults and those with non-amnestic MCI. People with amnestic MCI are many times more likely to develop Alzheimer’s disease than those with non-amnestic MCI.
The test cannot identify who will definitely develop Alzheimer’s disease. But if larger studies confirm the findings, it could help doctors assess early on which patients are at high risk and could benefit most from new Alzheimer’s drugs such as donanemab and lecanemab.
All of the tests were performed in people’s homes, which Stothart said was important for making them accessible and reducing people’s anxiety. Details are published in Brain Communications.
Prof Vladimir Litvak, of UCL’s Queen Square Institute of Neurology, said it was “an early step towards developing a clinically useful test”. A crucial next step, he said, would be to determine whether it can predict how a person’s condition changes over time and inform decisions about their treatment.
Dr Julia Dudley, of Alzheimer’s Research UK, said: “It’s encouraging to see studies exploring potential ways to detect memory problems earlier. New Alzheimer’s treatments are proving to be more effective when given at earlier stages in the disease, therefore earlier diagnosis is key for people to benefit from this.
“Longer-term studies in larger, diverse groups of people are needed to find out if this technology can predict how memory problems will unfold over time. Memory impairment can also be linked to other health conditions, not just dementia. Future research should look at how other factors may influence brainwave test results and explore how these tests could work alongside other diagnosis tools like cognitive assessments and blood tests.”
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