Tools

Researcher shows spatial skills could lead to earlier indications of Alzheimer's disease

A massive research effort headed by a KU investigator deepens our understanding of how Alzheimer's disease affects our ability to think, especially in its earliest stages. David K. Johnson, KU professor of psychology, and colleagues from Washington University School of Medicine in St. Louis have shown that testing a person's aptitude with spatial relationships between objects - the skills needed to complete a jigsaw puzzle, for instance - could give an earlier indication of Alzheimer's disease than conventional methods involving verbal memory.

"We saw that there were not only verbal memory changes - the classical, hallmark features of Alzheimer's disease - but there were a lot of other cognitive declines as well, most notably visuospatial defect," Johnson said.

Johnson described visuospatial skills as the ability to interpret complex visual stimuli and know how to interact with them and use them for a particular task.

"For instance, one test that went into this is where someone looked at squares and triangles and circles and X's randomly strewn about a page, and they get to study that for 30 seconds," explained Johnson. "Then we take away the page and ask them to draw it from memory. Even if we put that piece of paper and leave it there in front of them and ask them to copy it, they're still having trouble interpreting that visual stimulus."

The researchers tracked 444 volunteers over the course of more than 25 years, assessing each for global cognition, verbal memory, working memory and visuospatial skills. Of the volunteers, 134 developed dementia and 44 were confirmed to have Alzheimer's disease.

Reviewing the data, Johnson and his colleagues determined that visuospatial skills, or aptitude with spatial correlations between objects, declined measurably "three years before clinical diagnosis."

"We're desperate to find a treatment that can halt or even reverse Alzheimer's disease," said Johnson. "We're pretty far away from that right now. What early diagnosis allows us to do is hopefully identify individuals that we can target new drugs for - and try to understand the biological underpinnings of the disease. If we can detect a person early enough, we have a much better chance of interfering with the disease, because by the time someone actually receives a diagnosis of Alzheimer's disease there's unfortunately pretty significant damage done already."

The results were issued this month in Archives of Neurology, a publication of the Journal of the American Medical Association. The National Institute on Aging, one of the National Institutes of Health, supported the study.