RSNA: Structural changes in brain offer early insight into Alzheimer’s

CHICAGO—Trying to further our understanding of the early signs of Alzheimer’s disease (AD), a study presented at the annual meeting of the Radiological Society of North America (RSNA) has shown changes in brain connections could be an early biomarker of the disease.

“We have findings that suggest there are early changes in the brain which we can detect with imaging that can help identify patients who are developing early Alzheimer’s and may benefit from early treatment,” said Jeffrey W. Prescott, MD, PhD, radiology resident at Duke University Medical Center in Durham, N.C., and co-author of the study.

Specifically, Prescott and colleagues used diffusion tensor imaging (DTI) to look at the structural connectome, a map of white matter tracts that carry signals between different areas of the brain. They sought to analyze topological metrics and their reproducibility in the setting of AD.

A total of 102 subjects were enrolled in the study, dubbed the Alzheimer’s Disease Neuroimaging Initiative 2, and all subjects underwent DTI and florbetapir PET data, which indicated amyloid plaque load.

Results showed significant associations between florbetapir uptake and decreases in strength in the structural connectome in the five cortical lobes studied: frontal, cingulate, parietal, temporal, and occipital. Prescott said the researchers suspect that the brain’s white matter starts to break down and lose its ability to move water and neurochemicals efficiently as the amyloid plaque load in the gray matter increases.

The results signal that one day it may be possible to use structural network topology as an image biomarker of AD, though more work is needed to definitively answer the big lingering questions of AD, such as identifying presymptomatic patients and figuring out how much time before they begin cognitive decline.

“These are questions that are pretty far away from being answered but they are the focus of a lot of work right now,” said Prescott.