A biomarker profile of elevated CSF p‐tau with normal tau PET is associated with increased tau accumulation rates on PET in early Alzheimer’s disease

Different tau biomarkers become abnormal at different stages of Alzheimer’s disease (AD), with CSF p‐tau typically being elevated at subthreshold levels of tau‐PET binding. To capitalize on the temporal order of tau biomarker‐abnormality and capture the earliest changes of tau accumulation, we selected a group of amyloid‐β‐positive (A+) individuals with elevated CSF p‐tau levels but negative tau‐PET scans and assessed longitudinal changes in tau‐PET, cortical thickness and cognitive decline.