Timing of Biomarker Changes in Alzheimer Disease Process

Alzheimer disease (AD) is associated with neuronal plaques and neurofibrillary tangles, which result from abnormal amyloid and tau processing, respectively. To explore the relative timing and rates of these changes during the AD process, researchers analyzed levels of one amyloid biomarker (cerebrospinal fluid [CSF] amyloid-beta_1-42 [Aβ_1-42]) and of two tau biomarkers (CSF total tau [T-tau] and adjusted hippocampal volume [AHV]) in 116 elderly patients with normal cognition, 196 with mild cognitive impairment (MCI), and 89 with dementia. To distinguish normal from abnormal biomarker levels, the researchers used cutoff values from separate autopsy cohorts of those who met clinical criteria for low- or high-probability of AD pathology.

Each bi…