Rates of age- and amyloid β-associated cortical atrophy in older adults with superior memory performance

Introduction: Superior cognitive performance in older adults may reflect underlying resistance to age-associated neurodegeneration. While elevated amyloid b (Ab) deposition (Ab1) has been associated with increased cortical atrophy, it remains unknown whether “SuperAgers” may be protected from Ab-associated neurodegeneration. Methods: Neuropsychologically defined SuperAgers (n 5 172) and cognitively normal for age (n 5 172) older adults from the Australian Imaging, Biomarkers and Lifestyle study were case matched. Rates of cortical atrophy over 8 years were examined by SuperAger classification and Ab status. Results: Of the case-matched SuperAgers and cognitively normal for age older adults, 40.7% and 40.1%, respectively, were Ab1. Rates of age- and Ab-associated atrophy did not differ between the groups on any measure. Ab2 individuals displayed the slowest rates of atrophy. Discussion: Maintenance of superior memory in late life does not reflect resistance to age- or Abassociated atrophy. However, those individuals who reached old age without cognitive impairment nor elevated Ab deposition (i.e. Ab2) displayed reduced rates of cortical atrophy