A specialized imaging test may provide new diagnostic help for the trickiest types of Alzheimer’s disease (AD)—early-onset and atypical forms. Researchers have long associated changes in the brain’s gray matter with AD, but the brain’s white matter may have a lot to do with when and how the disease develops, notes a new study published in the journal Radiology.
“Alzheimer’s is a gray matter disease,” Federica Agosta, MD, PhD, co-author of the study conducted at the Neuroimaging Research Unit, San Raffaele Scientific Institute in Milan, Italy, said in a news release. “However, white matter damage has a central role in how the disease strikes and progresses.”
Diffusion tensor imaging (DTI) uses magnetic resonance imaging technology to track how water molecues travel through the brain’s white matter, identifying small degenerative changes that other types of diagnistoic imaging would miss. Damage to the white tracts is usually a precursor to damage to gray matter later, researchers found.
“DTI has the potential to assess the extensive disorganization of brain networks in focal AD even before overt cognitive deficits become apparent,” Agosta said. Because the technology can detect a decline in brain function before actual memory loss and cognitive issues are noticable, it may help seniors receive earlier treatment, Agosta added. “Because there is not much structural damage in the early stages of focal Alzheimer's disease, there is a risk that patients may be misdiagnosed and excluded from clinical trials.”