Congratulations to Drs. David Vaillencourt, Melissa Armstrong, and Steven DeKosky
Drs. David Vaillencourt, Melissa Armstrong, and Steven DeKosky’s research “Semantic intrusion errors differentiate between amnestic MCI who are plasma p-tau217+ from p-tau217- after adjusting for initial learning strength,” was published in the July issue of Frontiers in Neurology.
Abstract
Background
Semantic intrusion errors (SIEs) are associated with mild cognitive impairment (MCI) due to Alzheimer’s disease (AD). It is unknown whether accounting for maximum learning capacity still leads to an increase in SIEs when elevated plasma p-tau 217 , a biological indicator of underlying AD, is present.
Methods
One hundred fifty-eight older adult participants completed the Loewenstein-Acevedo Scales for Semantic Interference and Learning (LASSI-L), a sensitive cognitive challenge test designed to elicit SIEs. Of these, 108 were clinically diagnosed with amnestic MCI (aMCI). Fifty-eight individuals met or exceeded a plasma p-tau 217 positivity of > 0.5 5 pg/ml, while 50 individuals scored below this threshold.
Results
After adjusting for demographic covariates and maximum learning capacity, the aMCI p-tau 217 + group evidenced more SIEs compared to aMCI p-tau 217 – on the first (list B1; p = 0.035) and second trials of the competing list (list B2; p = 0.006). Biological predictors such as ApoE ε4 status, higher p-tau 217, and older age were predictors of an elevated number of SIEs [list B2: F (3,104) = 10.92; p = 0.001; R = 0.489)].
Conclusions
Unlike previous studies that used amyloid PET or other plasma biomarkers, individuals with aMCI p-tau 217 + evidenced more SIEs, even after adjusting for their initial learning capacity, a covariate that has not been studied previously. These findings support that SIEs are more prevalent in the presence of underlying AD pathology and occur independent of learning deficits.