Spatial patterns on imaging could predict Alzheimer's years before cognitive symptoms emerge
Small changes in cortical microstructure on MR imaging could help identify individuals who might be vulnerable to developing Alzheimer’s disease, new research suggests.
Published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, the new study builds on the authors’ prior research into the relationship between cortical microstructure alterations and the onset of cognitive impairment later in life. This latest research goes a step further by analyzing how the spatial patterns of these changes can predict and potentially prevent issues with memory and the development of AD specifically.
“We were interested in examining if changes in this measure over time are linked to memory changes, and how the spatial patterns of these changes can tell us about a person’s risk of developing cognitive impairment and AD,” first author of the study Rongxiang Tang, PhD, with the department of psychiatry and Center for Behavior Genetics of Aging at the University of California San Diego, noted in a news release. “Tracking these cortical microstructural changes early on in the aging process may be beneficial for early risk identification of cognitive impairment and AD."
For the study, a group of 194 adults in their 60s underwent two MRI scans over a period of five to six years. Researchers used the patients’ MRI exams to create maps tracking the changes in their cortical mean diffusivity over time.
The participants, who did not have dementia or symptoms suggesting that they would develop the neurological condition, then had their exams compared alongside the PET imaging of a group of patients who did have AD and were involved in a separate study. Participants also underwent a series of exams to assess their episodic memory.
Through this, the team observed associations between memory decline and patterns of microstructural changes that more closely resembled stereotypical tau deposition on imaging. Greater changes in these patterns on imaging were linked to more issues with memory at the end of the study period.
These subtle changes precede greater tissue loss related to cognitive impairment, the group explained, indicating that their presence could signal the development of memory problems or AD in the future.
"We found that the spatial pattern of microstructural change in our participants closely resembled the typical tau pathology deposition map seen in AD patients,” senior author Jeremy A. Elman, PhD, an assistant adjunct professor for the department of psychiatry at UC San Diego, explained. “Because tau is considered to be a major contributor to neurodegeneration (brain shrinkage) and cognitive decline, our results suggest that tracking these cortical microstructural changes and their spatial change patterns early on in the aging process may be beneficial for early identification of risk for cognitive impairment and AD."
The team suggested that their findings could lay the groundwork for tracking the development of AD prior to cognitive decline, potentially enabling providers to initiate risk-reducing treatments sooner.
The study abstract is available here.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.