Research Review

Memory Problems Not the Only Predictor of Later MCI

Mild cognitive impairment (MCI) is often seen as a transition stage between the cognitive decline of normal aging and the more serious problems of Alzheimer's disease. But what leads to mild cognitive impairment?

Researchers at Rush University Medical Center have found that lower, though not necessarily impaired, performance on tests measuring story learning or retention and processing speed in motor tasks dependent on visual control, as well as symptoms of depression, predicted subsequent cognitive decline in a normal population. The study is published in the Journal of the International Neuropsychological Society.

None of the factors alone predicted the onset of MCI a year later. Rather, poor learning had to be accompanied by either slower visuomotor processing speed or depressive symptoms to be significantly related to later problems in cognition.

Using an advanced statistical methodology that analyzed multiple variables at once, the researchers also found that neither gender nor the apolipoprotein E genotype—long believed to be risk factors for MCI—had any substantial influence on later impairment.

The 94 individuals who participated in the study underwent a battery of standard cognitive and psychosocial tests to assess mood, attention, visuospatial abilities, language facility, memory, and intelligence. These included the Trail-Making Test, which measures motor speed, visual attention, and cognitive flexibility; the Wisconsin Card Sorting Test, which measures the ability to problem solve; a delayed recall test; the American National Adult Reading Test; and the Geriatric Depression Scale. Information was collected on age, education, gender, and genotype.

Lower performance on tests measuring learning, when paired with either slower speed on the Trail-Making Test or a lower score on the depression scale, predicted the development of MCI a year later with an accuracy of 80% to 100% in the test sample.

— Source: Rush University Medical Center