2022 Alzheimer's Association Research Grant (AARG)

Enhanced Detection of Cortical Atrophy as a Biomarker of Early Decline

Can subtle changes in the cortex, an area of the brain known to be important for cognition, predict cognitive decline?

Kara Garcia, Ph.D., M.E.
Indiana University
Bloomington, IN - United States

Background

Research suggests brain changes observed in Alzheimer’s disease start decades before clinical signs are evident. One of the early brain changes associated with Alzheimer’s is a reduction in the thickness and volume of a brain region known as the cortex, which is important for cognitive functioning. In the advanced stages of Alzheimer’s, reductions in the volume or thickness of the cortex can be reliably detected using brain scans. However, in earlier stages of the disease, these changes can be subtle and more difficult to detect.

Most studies investigating physical changes in the cortex focus on cortical thickness, despite emerging evidence that cortical thickness is a less sensitive measure than cortical volume. In addition, little is known about how cortical thickness and volume change over time in individuals as they age or as they develop Alzheimer’s. More precise measurements of physical changes in the cortex at the individual-patient level may be necessary if these measures are to be used to help prognosis and treatment.
 

Research Plan

Dr. Kara Garcia and colleagues will study a more precise measure of cortical reduction, defined as the change in cortical volume within an individual over a known period of time. Previously, the researchers developed an analysis tool to map changes in the brain over time.  The team will use their novel tool to analyze areas of the brain, including in the cortex using images in an on-going study called the Alzheimer’s disease Neuroimaging Initiative (ADNI). The research team will also use their novel tool to evaluate changes in images collected by the IADRC through the Indiana Memory and Aging Study (IMAP).

Dr. Garcia and colleagues will investigate the changes in the cortex among individuals with Alzheimer’s over one to two years. In addition, they will see whether their novel analysis tool may help detect subtle changes in the cortex in individuals with preclinical Alzheimer’s. Finally, the team will compare their technique to standard methods of measuring physical changes in the cortex and determine which is superior at predicting cognitive decline.
 

Impact

The results of this study may shed new light on physical brain changes that occur in the earliest stages of Alzheimer’s, including those that precede the symptoms of Alzheimer’s. If successful, the findings may help identify reductions in cortical volume as a potential imaging biomarker of Alzheimer’s.