New AI Test Predicts Dementia 9 Years in Advance with 82% Accuracy

A new test can predict dementia with 82% accuracy, according to researchers at Queen Mary University of London in the U.K.Analyzing 1,111 functional magnetic resonance imaging (fMRI) scans of people with and without dementia, the researchers produced a model using machine learning. They say it spots the telltale signs of dementia up to nine years before diagnosis. 

The model identifies changes in the brain’s default mode network (DMN). The DMN is active when a person is lying in an fMRI scanner, not doing anything. The DMN state is believed to play a role in daydreaming and introspection, among other activities. It is more active when a person is at rest or engaged in self-referential thought. 

The researchers collected the fMRI scans used in the study from the UK Biobank. The participants included 81 people who had not been diagnosed with dementia at the time their scans were taken, but who developed the condition up to nine years afterward. For comparison, 1,030 people served as matched controls for the study.The researchers examined disconnects between 10 key regions within the DMN, using machine learning to construct their model. 

When they applied their model to medical records of the participants, they found it accurately predicted dementia within a two-year window during which is when such a diagnosis would occur.The authors of the study also looked for associations between DMN disconnectivity and various dementia risk factors. They found links between the model and social isolation — which has been linked to the likelihood of developing Alzheimer’s disease — as well as a genetic risk for the condition. 

The hope is that early detection may one day provide a chance for early interventions that may forestall or prevent dementia. This is congruent with the current knowledge of Alzheimer’s and other brain changes within years.Researchers explained that Alzheimer’s is a cortical dementia with damage to the cortex of the brain, and there is vascular dementia, which is a subcortical dementia that involves damage to the white matter of the brain. 

In practice, a large majority of dementia is due to either Alzheimer’s disease on its own or mixed Alzheimer’s and vascular dementia.Early detection of cognitive issues is one vital part of helping patients, with effective treatments being the other.If these tests pan out to have some clinical utility in the future these patients would be followed by more frequent 3T structural MRI scans to determine if there were anatomical changes that would correlate with their memory loss.