Cross-Sectional Associations of CSF Tau Levels With Rey's AVLT: A Recency Ratio Study

Objective: The preeminent in vivo cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) are amyloid β 1-42 (Aβ42), phosphorylated Tau (p-tau), and total Tau (t-tau). The goal of this study was to examine how well traditional (total and delayed recall) and process-based (recency ratio [Rr]) measures derived from Rey's Auditory Verbal Learning test (AVLT) were associated with these biomarkers. Method: Data from 235 participants (M age = 65.5, SD = 6.9), who ranged from cognitively unimpaired to mild cognitive impairment, and for whom CSF values were available, were extracted from the Wisconsin Registry for Alzheimer's Prevention. Bayesian regression analyses were carried out using CSF scores as outcomes, AVLT scores as predictors, and controlling for demographic data and diagnosis. Results: We found moderate evidence that Rr was associated with both CSF p-tau (Bayesian factor [BFM] = 5.55) and t-tau (BFM = 7.28), above and beyond the control variables, while it did not correlate with CSF Aβ42 levels. In contrast, total and delayed recall scores were not linked with any of the AD biomarkers, in separate analyses. When comparing all memory predictors in a single regression, Rr remained the strongest predictor of CSF t-tau levels (BFM = 3.57). Conclusions: Our findings suggest that Rr may be a better cognitive measure than commonly used AVLT scores to assess CSF levels of p-tau and t-tau in nondemented individuals. Key Points Question: This article asks how well process-based measures derived from Rey's Auditory Verbal Learning test (AVLT), such as the recency ratio (Rr), associate with cerebrospinal fluid (CSF) levels of Alzheimer's disease (AD) biomarkers when compared to traditional measures (e.g., total and delayed recall). Findings: The results of this study indicate that Rr outperforms AVLT total and delayed recall in predicting CSF levels of t-tau cross sectionally. Importance: These findings highlight the importance of process-based measures for the identification of individuals at risk of neurodegeneration. Next Steps: More research is needed to examine Rr clinical value among individuals presenting with a neurodegenerative disease.