In this issue of JAMA Neurology, Gordon and colleagues1 from Washington University publish a well-done study on an important and topical subject. The investigators used the 2-class Alzheimer disease (AD) biomarker classification scheme that arises when combining biomarker staging for preclinical AD recommended by the National Institute on Aging–Alzheimer Association2 along with suspected non-Alzheimer pathophysiology (SNAP) described by the Mayo group.3 Every participant is placed into 1 of 4 biomarker categories based on dichotomizing biomarkers for β-amyloidosis (Aβ) and neurodegeneration/neuronal injury (ND): Aβ−/ND− (stage 0 preclinical AD), Aβ+/ND− (stage 1 preclinical AD), Aβ+/ND+ (stage 2/3 preclinical AD), Aβ−/ND+ (SNAP).
Jack CR. Brain Atrophy on Magnetic Resonance Imaging as a Biomarker of Neurodegeneration. JAMA Neurol. 2016;73(10):1179–1182. doi:10.1001/jamaneurol.2016.2843