Researchers at Stanford Medicine have found that resting brain activity may be an early indicator of Alzheimer’s disease, potentially allowing for predictions years before memory decline becomes apparent. The study examined how brain regions interact during resting states to ascertain who might later experience memory issues.
The study involved two distinct groups: 110 individuals diagnosed with Alzheimer’s disease and 180 adults aged 75 and older, known as SuperAgers, who exhibit exceptional memory capabilities for their age. Researchers used functional MRI scans to monitor brain activity by detecting changes in blood oxygen levels as participants rested.
According to Kanhao (Alex) Zhao, a postdoctoral researcher in computational neuroscience at Stanford and the study’s lead author, the analysis revealed differing connectivity patterns in the brains of the two groups. SuperAgers displayed stronger connections in certain frontal brain regions, while those with Alzheimer’s exhibited more robust connections involving the insula, a deeper brain region. Zhao noted, “This suggests that Alzheimer’s vulnerability may be reflected in how the brain functions as an interconnected system.”
From these patterns, the researchers created an assessment tool called the Alzheimer’s Resilience–Vulnerability Connectome (ARC). This score indicates whether an individual’s brain connectivity resembles that of SuperAgers, correlating lower scores with better cognitive health and higher scores with greater risk for Alzheimer’s. When tested on a separate group of 143 individuals, the ARC successfully categorized about 71 percent accurately.
The team next investigated whether ARC scores could indicate future cognitive health in individuals with no current signs of impairment. Evaluating 1,315 cognitively healthy participants, they found that those with higher ARC scores—more reflective of Alzheimer’s—tended to experience faster declines in memory and daily functioning over a follow-up period of five to 12 years. Moreover, these individuals were more likely to develop Alzheimer’s or mild cognitive impairment, while those with lower scores maintained their cognitive abilities for a longer period.
Interestingly, follow-up scans revealed that individuals with more Alzheimer’s-like brain scans demonstrated faster accumulation of amyloid beta, a protein associated with plaque buildup in Alzheimer’s patients, despite similar initial levels among both groups. However, no significant differences were noted regarding tau protein accumulation.
This research indicates that incorporating ARC scores could enhance predictions of who is at risk for mild cognitive impairment or Alzheimer’s beyond current methods that utilize age, amyloid beta and tau measurements, and APOE genetic risk factors. Zhao remarked on the potential of these findings but emphasized the need for larger studies to validate these results and improve accuracy in clinical assessments.
The research was published in the journal Science Advances.
