Identifying cognitive test scores associated with early tau burden in Alzheimer's disease.

Introduction: This study aimed to identify cognitive tests that optimally relate to tau positron emission tomography (PET) signal in the inferior temporal cortex (ITC), a neocortical region associated with early tau accumulation in Alzheimer's disease (AD).

Methods: We analyzed cross-sectional data from the harvard aging brain study (HABS) (= 128) and the Anti-Amyloid Treatment in Asymptomatic Alzheimer's (A4) study (= 393). We used elastic net regression to identify the most robust cognitive correlates of tau PET signal in the ITC. Secondary analyses examined whether the cognitive correlates remained significantly associated with tau after adjusting for structural brain measures.

Results: Episodic memory measures, including both total and "process" scores, were the most robust correlates of ITC tau across both cohorts. These cognitive test scores remained significant after accounting for structural brain measures.

Discussion: These findings highlight the potential of specific episodic memory test scores to detect and monitor neuropathological changes associated with early AD.

Highlights: Machine learning identified cognitive correlates of early Alzheimer's disease tau burden.Both traditional and process scores predicted early tau burden.Episodic memory scores were among the strongest correlates.Cognitive scores remained significant after accounting for structural brain measures.