A simple test may be able to help detect heightened risk for developing Alzheimer's disease in a person, even before there are any telltale behavioral signs of dementia.
Researchers from York University found that examining thinking and movement via four increasingly demanding visual-spatial and cognitive motor tasks can detect the tendency for Alzheimer's in those who were having cognitive difficulty even though they were not showing outward signs of the disease.
"We included a task which involved moving a computer mouse in the opposite direction of a visual target on the screen, requiring the person's brain to think before and during their hand movements," researcher Lauren Sergio said in a statement. "This is where we found the most pronounced difference between those with mild cognitive impairment (MCI) and family history group and the two control groups."
Kara Hawkins, who led the study, said well-learned, stereotyped motor behaviors are preserved until very late in Alzheimer's disease. These include routine movements, such as walking. The disruption in communication will be evident when movements require the person to think about what it is they are trying to do.
For the test, participants were divided into three groups -- those diagnosed with MCI or had a family history of Alzheimer's disease, and two control groups, young adults and older adults, without a family history of the disease.
The research team found that 81.8 percent of the participants that had a family history of the neurodegenerative disease and those with MCI displayed difficulties on the most cognitively demanding visual motor task.
"The brain's ability to take in visual and sensory information and transform that into physical movements requires communication between the parietal area at the back of the brain and the frontal regions," Sergio explained. "The impairments observed in the participants at increased risk of Alzheimer's disease may reflect inherent brain alteration or early neuropathology, which is disrupting reciprocal brain communication between hippocampal, parietal and frontal brain regions."
Hawkins said they were able to categorize the low Alzheimer's disease risk and the high Alzheimer's disease risk using kinematic measures. The finding don't predict who will develop Alzheimer's disease, but they do show there is something different in the brains of most of the participants diagnosed with MCI or who had a family history of the disease.
The study was published in the Journal of Alzheimer's Disease.
