Tau and memory performance in women: Advantages of visuospatial over standard verbal memory tests

Abstract

AbstractBackgroundThe accumulation of pathological tau in the medial temporal lobe is a hallmark of early Alzheimer’s disease (AD) that leads to memory decline. The majority of studies in AD use exclusively verbal memory tests to detect this memory loss, which is problematic because women have a lifelong advantage in verbal memory such that these tests may be less responsive to early AD. In our Women: Inflammation and Tau Study (WITS), we used both verbal and nonverbal memory tests, with the hypothesis that the nonverbal test would more accurately reflect tau in women.MethodWITS is a study of older women (aged 65+) with high risk for AD by way of the AD polygenic hazard score and mild cognitive deficits. Data are from 16 participants thus far. Tau PET imaging was completed using the MK6240 ligand. Two volume‐weighted composite of Braak III&IV regions and metatemporal regions were our regions of interest (ROIs). Memory tests were the Rey Auditory Verbal Learning Test (RAVLT) and Brief Visuospatial Memory Test‐Revised (BVMT). Both tests have multiple learning trials in addition to delayed recall. A series of linear regression models separately examined RAVLT and BVMT scores in relation to tau burden in each ROI. We used Akaike Information Criterion (AIC) to compare model fits.ResultPoorer performance in both RAVLT and BVMT delayed recall was significantly related to greater tau in each ROI (ps<.01); however, relationships were stronger with the BVMT. For the metatemporal ROI, RAVLT explained 14.6% of the variance in tau, while BVMT explained 44.6% (Figure 1). For the Braak III&IV ROI, RAVLT explained 10.1% of the variance and BVMT explained 29.8%. The AIC implied superiority of the models with BVMT over the models with RAVLT.ConclusionOur preliminary results show that tau burden in women is better reflected by visual memory performance than verbal memory. Reliance on verbal memory may not be ideal in studies of AD involving women. Upon replication, our results suggest that visual memory performance may be a more accurate clinical marker of early AD with better prognostic value in women that can lead to improved effect sizes and more efficient clinical trials.