Metabolic brain network reorganization precedes clinical conversion in Alzheimer's disease
Introduction: Brain glucose hypometabolism is a hallmark of Alzheimer's disease (AD), yet conventional [18F]-fluorodeoxyglucose (FDG) positron emission tomography (PET) analyses have limited sensitivity in preclinical stages. Metabolic brain network approaches may better capture early vulnerability preceding clinical conversion. Methods: Cognitively unimpaired individuals (n = 127) from the ADNI…
A pioneering study identifies metabolic brain network reorganization as a precursor to clinical conversion in Alzheimer's disease (AD), even before the presence of amyloid or tau biomarkers. Researchers analyzed 127 cognitively unimpaired individuals from the ADNI cohort, tracking brain glucose metabolism through conventional FDG-PET analyses.
Conventional methods failed to differentiate between those who remained stable and those who progressed to clinical conversion. However, a closer look at metabolic brain networks unveiled significant differences between the two groups. Clinical converters exhibited hyperconnected metabolic networks, particularly within the default-mode network, even before amyloid positivity became detectable.
This hyperconnectivity was consistent across different AD biomarker profiles, including A-T-, A+T-, and A+T+ groups. In contrast, stable individuals showed a decline in network density as AD progression progressed. This discovery suggests that metabolic network organization may reflect divergent trajectories of resilience and pathological propagation, potentially identifying individuals at risk of clinical progression at an early stage.
By repurposing existing FDG-PET datasets, this framework offers a valuable tool for large-scale risk assessment in AD.
Written by urgent.news from bioRxiv's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
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