Subjective cognitive decline linked to global tau burden

(HealthDay)—For clinically healthy older adults, subjective cognitive decline (SCD) is associated with increasing entorhinal cortical tau burden and β-amyloid (Aβ) burden, according to a study published online Oct. 2 in JAMA Neurology.

Rachel F. Buckley, Ph.D., from the University of Melbourne in Australia, and colleagues examined the correlations between SCD and global Aβ and tau burdens in clinically healthy older adults. Data were included for 133 clinically healthy older participants who underwent cross-sectional flortaucipir F18 positron emission tomography (PET) imaging and Pittsburgh compound B carbon 11-labeled PET imaging for tau and Aβ, respectively.

The researchers found that 29.3 percent of participants exhibited high Aβ burden. There was a correlation for greater SCD with increasing entorhinal cortical tau burden and Aβ burden but not inferior temporal tau burden. After accounting for Aβ burden, the correlation between entorhinal cortical tau burden and SCD was largely unchanged; no interaction influenced SCD. In post hoc whole-brain analysis, SCD was mainly associated with greater tau burden in the entorhinal cortex.

"Subjective cognitive decline is indicative of accumulation of early tauopathy in the medial temporal lobe, specifically in the entorhinal cortex, and to a lesser extent, elevated global levels of Aβ," the authors write. "Our findings suggest multiple underlying pathways that motivate SCD that do not necessarily interact to influence SCD endorsement. As such, multiple biological factors must be considered when assessing SCD in clinically healthy older adults."

Several authors disclosed financial ties to the pharmaceutical industry.

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