Associations between different tau-PET patterns and longitudinal atrophy in the Alzheimer's disease continuum

INTRODUCTIONDifferent subtypes/patterns have been defined using tau-PET and structural-MRI in Alzheimers disease (AD), but the relationship between tau pathology and atrophy remains unclear. Our goals were twofold: (a) investigate the association between baseline tau-PET patterns and longitudinal atrophy in the AD continuum; (b) characterize heterogeneity as a continuous phenomenon over the conventional notion using discrete subgroups. METHODSIn 366 individuals (amyloid-beta-positive: cognitively normal, prodromal AD, AD dementia; amyloid-beta-negative healthy), we examined the association between tau-PET patterns (operationalized as a continuous phenomenon and a discrete phenomenon) and longitudinal sMRI. RESULTSWe observed a differential association between tau-PET patterns and longitudinal atrophy. Heterogeneity, measured continuously, may offer an alternative characterization, sharing correspondence with the conventional subgrouping. DISCUSSIONSite and the rate of atrophy are modulated differentially by tau-PET patterns in the AD continuum. We postulate that heterogeneity be treated as a continuous phenomenon for greater sensitivity over the current/conventional discrete subgrouping.