COGNITIVE MARKERS OF PROGRESSION FROM NORMAL COGNITION TO MCI AND FROM MCI TO DEMENTIA ACROSS EUROPEAN AND HISPANIC AMERICANS

Objective: Our main objectives were to identify cognitive markers of progression to a more severe cognitive diagnosis, explore possible differences between ethnic groups and to correlate cognitive markers of progression with biomarkers of AD (hippocampal and entorhinal volumes) and frontal volumes (lateral orbitofrontal, medial orbitofrontal, superior frontal, and rostral middle frontal volumes). Method: 207 participants (Mage = 71.79, SD = 7.48, 123 Hispanic Americans [HA]) were followed for an average of 23 months. Participants were classified into 3 diagnostic groups (Cognitively normal [CN], mild cognitive impairment [MCI], or dementia) based on the CDR global score and the neuropsychological baseline data was used as predictors of progression status. For the CN group, the Benson Figure delayed recall was a predictor of cognitive decline, and within the MCI group, the Benson delayed recall, the HVLT immediate recall, the TMTB, category fluency, and three measures of the LASSI-L (A1 cued recall, A2 cued recall, and delayed recall) were significant predictors of progression to dementia and are suggested as cognitive markers of progression for MCI individuals. Memory cognitive markers and category fluency correlated with medial temporal lobe volumes, and the TMT-B correlated with superior frontal volume. We did not observe significant differences in cognitive markers across ethnic groups. Conclusion: we identified cognitive markers of progression for CN and for MCI diagnoses which were not different across ethnic groups. These findings contribute to literature on the early identification of individuals at risk of progression to a more severe cognitive status even within asymptomatic individuals which can facilitate a more time- and cost-effective practice that is essential to the provision of the appropriate treatment to those at higher risk of progression.