NIH Toolbox® Episodic Memory Measure Differentiates Older Adults with Exceptional Memory Capacity from those with Average-for-Age Cognition.

OBJECTIVE: Older adults with exceptional memory function, designated "SuperAgers," include individuals over age 80, with episodic memory at least as good as individuals ages 50s-60s. The Northwestern University SuperAging cohort is defined by performance on an established test of verbal memory. The purpose of this study was to determine if superior verbal memory extends to nonverbal memory in SuperAgers by examining differences in the National Institutes of Health Toolbox® (NIHTB) between older adults with exceptional memory and those with average-for-age cognition. METHOD: SuperAgers (n = 46) and cognitively average-for-age older adults (n = 31) completed a comprehensive neuropsychological battery and the NIHTB Cognition module. Multiple linear regressions were used to examine differences on subtests between groups. RESULTS: There was a significant effect of group on the Picture Sequence Memory score, (p = .007), such that SuperAgers had higher scores than cognitively average-for-age older adults. There were no other group effects across other non-episodic memory NIHTB Cognition measures. CONCLUSIONS: Findings from this study demonstrated stronger performance on the memory measure of the NIHTB in SuperAgers compared to cognitively average-for-age older adults demonstrating superior memory in not only verbal but also nonverbal episodic memory in this group. Additionally, this study adds to the literature validating the NIHTB in older adults, particularly in a novel population of adults over age 80 with exceptional memory.

Neuropsychological Profiles of Older Adults with Superior versus Average Episodic Memory: The Northwestern "SuperAger" Cohort.

OBJECTIVE: SuperAgers are adults over the age of 80 with superior episodic memory performance and at least average-for-age performance in non-episodic memory domains. This study further characterized the neuropsychological profile of SuperAgers compared to average-for-age episodic memory peers to determine potential cognitive mechanisms contributing to their superior episodic memory performance. METHOD: Retrospective analysis of neuropsychological test data from 56 SuperAgers and 23 similar-age peers with average episodic memory was conducted. Independent sample t-tests evaluated between-group differences in neuropsychological scores. Multiple linear regression determined the influence of non-episodic memory function on episodic memory scores across participants. RESULTS: As a group, SuperAgers had better scores than their average memory peers on measures of attention, working memory, naming, and speeded set shifting. Scores on tests of processing speed, visuospatial function, verbal fluency, response inhibition, and abstract reasoning did not differ. On an individual level, there was variability among SuperAgers with regard to non-episodic memory performance, with some performing above average-for-age across cognitive domains while others performed in the average-for-age range on non-memory tests. Across all participants, attention and executive function scores explained 20.4% of the variance in episodic memory scores. CONCLUSIONS: As a group, SuperAgers outperformed their average memory peers in multiple cognitive domains, however, there was considerable intragroup variability suggesting that SuperAgers' episodic memory strength is not simply related to globally superior cognitive functioning. Attention and executive function performance explained approximately one-fifth of the variance in episodic memory and maybe areas to target with cognitive interventions.

Paucity of Entorhinal Cortex Pathology of the Alzheimer's Type in SuperAgers with Superior Memory Performance.

Advancing age is typically associated with declining memory capacity and increased risk of Alzheimer's disease (AD). Markers of AD such as amyloid plaques (AP) and neurofibrillary tangles (NFTs) are commonly found in the brains of cognitively average elderly but in more limited distribution than in those at the mild cognitive impairment and dementia stages of AD. Cognitive SuperAgers are individuals over age 80 who show superior memory capacity, at a level consistent with individuals 20-30 years their junior. Using a stereological approach, the current study quantitated the presence of AD markers in the memory-associated entorhinal cortex (ERC) of seven SuperAgers compared with six age-matched cognitively average normal control individuals. Amyloid plaques and NFTs were visualized using Thioflavin-S histofluorescence, 6E10, and PHF-1 immunohistochemistry. Unbiased stereological analysis revealed significantly more NFTs in ERC in cognitively average normal controls compared with SuperAgers (P < 0.05) by a difference of ~3-fold. There were no significant differences in plaque density. To highlight relative magnitude, cases with typical amnestic dementia of AD showed nearly 100 times more entorhinal NFTs than SuperAgers. The results suggest that resistance to age-related neurofibrillary degeneration in the ERC may be one factor contributing to preserved memory in SuperAgers.

Alzheimer's polygenic hazard score in SuperAgers: SuperGenes or SuperResilience?

Introduction: SuperAgers are individuals over age 80 with superior episodic memory, at a level consistent with individuals 20 to 30 years their junior and who seem to show resistance to age-related neurofibrillary degeneration. Here we examine whether low genetic risk for Alzheimer's disease (AD) contributes to SuperAgers' unusually high episodic memory performance in advanced age. Methods: The AD polygenic hazard score (PHS) was calculated for each SuperAger and cognitively normal participant and compared between groups. Results: A total of 37 SuperAgers (73% female, mean [standard deviation] 82.7 [2.8] years old) and 35 controls (54% female, 83.7 [4.3] years old) were included. There was no significant difference in the AD PHS between SuperAgers and cognitively normal controls. Discussion: Unusually successful cognitive aging cannot be simply explained by low polygenic risk for AD as assessed by common genetic variants. However, rare variants and common protective genetic factors may contribute to resistance or resilience. Highlights: SuperAging cannot be simply explained by low polygenic risk for Alzheimer's disease.Rare variants and common protective genetic factors may contribute to SuperAging.A protective factors polygenic score may uncover mechanisms for SuperAging.

A randomized trial to measure the impact of a community-based cognitive training intervention on balance and gait in cognitively intact Black older adults.

INTRODUCTION: Fall prevention is important for maintaining mobility and independence into old age. Approaches for reducing falls include exercise, tai chi, and home modifications; however, causes of falling are multifactorial and include not just physical but cognitive factors. Cognitive decline occurs with age, but older adults with the greatest declines in executive function experience more falls. The purpose of this study was twofold: to demonstrate the feasibility of a community-based cognitive training program for cognitively intact Black older adults and to analyze its impact on gait and balance in this population. METHOD: This pilot study used a pretest/posttest randomized trial design with assignment to an intervention or control group. Participants assigned to the intervention completed a computer-based cognitive training class that met 2 days a week for 60 min over 10 weeks. Classes were held at senior/community centers. Primary outcomes included balance as measured by the Berg Balance Scale (BBS), 10-meter gait speed, and 10-meter gait speed under visuospatial dual-task condition. All measures were assessed at baseline and immediately post-intervention. RESULTS: Participants were community-dwelling Black adults with a mean age of 72.5 and history of falls (N = 45). Compared to controls, intervention participants experienced statistically significant improvements in BBS and gait speed. Mean performance on distracted gait speed also improved more for intervention participants compared to controls. CONCLUSION: Findings from this pilot randomized trial demonstrate the feasibility of a community-based cognitive training intervention. They provide initial evidence that cognitive training may be an efficacious approach toward improving balance and gait in older adults known to have a history of falls.