New brain imaging tool distinguishes between Alzheimer’s disease and SuperAgers

Research published in November in Science Advances explores the ability of a new tool to distinguish differences in cognitive function between SuperAgers and individuals with Alzheimer’s disease.

The study defines SuperAgers as adults ages 75 years or older with “superior episodic memory performance” compared with adults under the age of 65. They also have executive function “comparable to age-matched older adults.”

The researchers developed the new brain-scoring imaging tool, called Alzheimer’s Resilience-Vulnerability Connectome, to compare the resting state functional magnetic resonance imaging (fMRI) of SuperAgers and people with symptomatic Alzheimer’s disease.

This allowed them to map a spectrum of brain aging that could help predict cognitive decline.

While these early findings show some promise in monitoring cognitive function for potential risk of Alzheimer’s disease before symptoms appear, further research is necessary.

ARC distinguished SuperAgers from Alzheimer’s with 0.85 accuracy.

ARC distinguished SuperAgers from those with Alzheimer’s disease with an accuracy of 0.85 (AUC).

To reach this score, the researchers used the tool to examine data from 180 SuperAgers and 110 people with Alzheimer’s disease. Each person was at least 75 years old.

They then used ARC to examine data from 818 cognitively healthy people in a slightly younger age group. ARC was able to map where each individual fell on the spectrum between Alzheimer’s disease and SuperAgers.

Medical News Today spoke with Dung Trinh, MD, internist, of MemorialCare Medical Group and Chief Medical Officer of Healthy Brain Clinic in Irvine, CA, about these findings.

“An AUC of 0.85 is a good result and suggests that ARC can distinguish fairly well between the brain connectivity patterns of SuperAgers and those of people with Alzheimer’s disease,” said Trinh, who was not involved in the study.

“It measures how well the model separates two groups, and, in this case, the researchers were comparing people at opposite ends of the cognitive spectrum. When the model was tested in an independent group, the AUC was lower, around 0.72. So, while the results are encouraging, we still have work to do before considering this clinically useful.,” he added.

“What I find significant is that researchers were able to detect measurable differences in how brain regions communicate. This gives us another potential way to study cognitive aging beyond looking at memory test scores or Alzheimer’s biomarkers. The bigger question is whether these patterns can reliably tell us who will develop cognitive impairment years down the road.

– Dung Trinh, MD

The importance of studying SuperAgers

MNT asked Trinh about the importance of studying SuperAgers in relation to Alzheimer’s disease.

“[T]hese are individuals who are aging exceptionally well from a cognitive standpoint. We spend so much time studying what goes wrong in the brains of people with Alzheimer’s disease, but I think it’s just as important to understand what is going right in people who maintain excellent memory into their 80s and 90s,” Trinh said.

“By comparing brain activity in SuperAgers with that of people with Alzheimer’s, researchers may be able to identify patterns associated with cognitive resilience. I think this opens up an important area of research because if we can better understand what makes some brains more resilient, we may eventually be able to develop strategies that help more people maintain their cognitive health as they age,” he explained.

Seán Kennelly, Consultant Geriatrician and Cognitive Specialist Clinical Director at Re:Cognition Health, Dublin, added:

“I find the study of SuperAgers particularly fascinating because they help us understand why some people maintain exceptional memory and cognitive function well into later life, while others experience significant decline,”

Kennelly, who was also not involved in the study, explained that, “[b]y looking at how different areas of the brain communicate, researchers can identify patterns associated with cognitive resilience. This gives us valuable insight into what a healthy ageing brain looks like and, importantly, what might make some people more vulnerable to Alzheimer’s disease.”

He said, “Ultimately, understanding these differences could help us move towards earlier identification and better prevention strategies.”

Identifying cognitive differences in cases of no cognitive impairment

The researchers examined whether ARC could identify differences in cognitive health among older adults without cognitive impairment.

This could help predict future cognitive decline and the development of Alzheimer’s disease before any symptoms or memory problems develop or appear on other cognitive tests.

Kennelly described this as “arguably the most significant finding from a clinical perspective.”

He explained that “[t]he researchers identified two groups of people who initially had similar cognitive abilities but very different patterns of brain activity. Those with more Alzheimer’s-like patterns subsequently experienced faster cognitive decline, greater amyloid accumulation and a higher risk of developing mild cognitive impairment or Alzheimer’s.”

He added, “The potential to identify vulnerability before symptoms appear is really important. It could give us an opportunity to monitor people more closely and explore interventions much earlier.”

Trinh agreed that “this is probably the most clinically relevant part of the study. We know that Alzheimer’s-related changes can begin in the brain 10 to 20 years before someone notices memory problems. By the time patients come into my office concerned about their memory, the disease process may have been developing for quite some time.”

He added, “In this study, the researchers found that, even among older adults who were cognitively normal, certain brain connectivity patterns were associated with faster cognitive decline and greater amyloid accumulation over time. That’s important because two people can perform equally well on a memory test today but have very different risks of cognitive decline in the future.”

Trinh explained that being able to identify those differences before symptoms appear “could help us determine who might benefit from closer monitoring or preventive interventions. Of course, having an Alzheimer’s-like connectivity pattern doesn’t mean someone will necessarily develop dementia. But it may provide another piece of information to help us better understand an individual’s risk.”