Abstract
We report the case of a 75-year-old patient with a clinically isolated and stable amnestic syndrome over fifteen years, despite a cerebrospinal fluid (CSF) profile strongly consistent with Alzheimer's disease (AD). Serial PET imaging over two years showed only limited amyloid accumulation, no significant tau deposition, no hypometabolism, and no neuroinflammation. This case illustrates a striking dissociation between biomarker positivity and clinical progression, raising important questions about individual resilience and the prognostic value of AD biomarkers in isolation.