Alzheimer’s is the most common cause of dementia in old age, with five to seven percent of people in Europe suffering from it. Because the progressive breakdown of brain matter has not yet been reversed, early detection and treatment as early as possible is particularly important. Researchers have now developed a method that can detect dementia using a simple EEG test – in a few minutes and without long reminder tasks. The “Fastball” test shows patients pictures of everyday objects in quick succession while their brain waves are recorded. The EEG pattern then reveals whether their memory-based recognition is already disturbed or not.
Alzheimer’s disease affects more than 1.3 million people in Germany alone, and the trend is rising. A typical characteristic of the disease is the accumulation of misfolded amyloid and tau proteins in the brain, which then gradually cause brain cells to perish. This breakdown of the brain substance usually begins insidiously and goes unnoticed by those affected. As a result, the diagnosis is often only made when the first failures become noticeable, for example in memory or in coping with everyday life. Alzheimer’s is usually diagnosed through a combination of memory tests, questioning, and mental tasks such as drawing a clock face. This is supplemented by imaging procedures using a brain scanner. However, these diagnostic methods only take effect when there are already subjectively noticeable failures – the breakdown of the brain substance is then well advanced.
Search for objective early signs of dementia
“The tests we are currently using to detect Alzheimer’s miss the first 20 years of the disease,” explains lead author George Stothart of the University of Bath. “As a result, we miss out on enormous opportunities to help patients earlier.” Because so far there has been no cure for dementia, nor any active ingredients or therapies that can reverse the damage to the brain. The existing active ingredients can at best slow the progression of Alzheimer’s disease. The earlier such treatments start, the greater the chance for those affected to postpone the most serious consequences for as long as possible. Scientists are therefore primarily working on diagnostic methods that do not depend on the subjective experience of the patient, but can detect the early signs of the disease objectively and independently of already noticeable memory deficits. Among other things, blood tests that look for certain biomarkers of brain breakdown are being tested.
Stothart and his colleagues have now developed another diagnostic option. Your method, dubbed “Fastball”, requires little active participation on the part of the patient and can be used with little effort even in a normal practice or even at home with the patient. All you need is a laptop or other computer and an electrode cap to conduct brain waves. Those affected are shown pictures of everyday objects in three test runs; some are repeated, others are new. So that the test subjects’ attention does not wander, they are asked to press a key as soon as a marking cross in the center of the image turns red. “The test person doesn’t have to understand the test or do a lot,” explains Stothart. “Just by the way your brain reacts to the images, we can learn a lot about what your brain can do or not.” The whole process only takes a few minutes.
Subtle changes in brain waves
The test is based on the evaluation of subtle changes in the brain waves, which indicate whether the test person recognizes a shown object or not and how effectively this memory-based recognition works for them. “Neuropsychological and imaging procedures indicate that the unconscious remembering and recognizing familiar things depend on regions of the brain that are particularly early affected by Alzheimer’s disease: the hippocampus and the perirhinal cortex,” the researchers explain. “We expect that patients with Alzheimer’s will therefore show a decreased performance in cognitive memory. While such changes would not be recorded in behavioral tests, Fastball is sensitive to these deficits. ”Even before conscious memory gaps occur, the EEG curves reveal whether the memory has been compromised.
How well this fastball test works was tested by Stothart and his team in a pilot study with 20 Alzheimer’s patients at a relatively early stage and healthy control persons of different ages. It was shown that the EEG test could identify Alzheimer’s patients with 86 percent accuracy, while classic psychological tests only managed around 63 percent. According to the scientists, such a test could move the Alzheimer’s diagnosis forward by up to five years in its current form. But they hope that they can extend this period even further. “We are only at an early stage of development,” explains Stothart. “We are now testing Fastball in ever earlier phases of Alzheimer’s disease and are expanding the brain activity that the test records.” The team is also already working on including verbal and other visual tests. “The long-term goal for diagnostic aids like this would be to be able to detect Alzheimer’s and other dementias in middle age long before symptoms appear,” says Stothart. “We are still very far from that, but our test is a small step in this direction.”
Source: George Stothart (University of Bath, UK) et al., Brain, doi: 10.1093 / brain / awab154