Memory profiling in mild cognitive impairment: Can we determine risk for Alzheimer's disease?

12 page(s

Memory Profiling With Paired Associate Learning in Alzheimer's Disease, Mild Cognitive Impairment, and Healthy Aging

Mild cognitive impairment (MCI) is associated with increased risk of developing Alzheimer's disease (AD), but up to 40% of cases do not develop AD. Examining a case's specific memory profile may help distinguish which MCI cases will progress to AD: An encoding profile is suggestive of incipient AD, whereas a retrieval profile suggests an alternative etiology. Paired associate learning (PAL) tasks are sensitive for preclinical and early detection of AD, but existing tasks do not enable memory profiling. We developed a novel PAL task enabling the differentiation of memory profiles in 19 people with AD, 17 people with amnestic MCI, and 33 normal elderly controls. Unexpectedly, the AD group demonstrated a retrieval profile for PAL using yes-no recognition, although an encoding profile was evident for forced-choice recognition and for the California Verbal Learning Test-Second Edition (Delis, Kramer, Kaplan, & Ober, 2000). There was considerable heterogeneity within the AD and MCI groups as well as intraindividual discordance for memory profiles. The findings challenge the clinical application of memory profiling in the differential diagnosis of AD, and, by extension, question its potential application in the assessment of MCI.11 page(s

Diabetes mellitus increases risk of incident dementia in APOE 4 carriers : A meta-analysis

Background:Dementia is a devastating condition for older adults, with both modifiable (e.g., diabetes mellitus) and unmodifiable risk factors (e.g., APOE ɛ4 allele). It remains unclear how, and to what extent, diabetes impacts dementia risk via both cerebrovascular and amyloid-β pathways. Objective:We conducted a quantitative meta-analysis to investigate the contribution of diabetes to incident dementia risk in people with ɛ4 and, based on the vascular-related neuropathology of diabetes, whether the combination of these factors increases risk for vascular dementia versus Alzheimer’s disease (AD). Methods:Systematic literature searches were conducted using EMBASE, MEDLINE, PsycINFO, and CINAHL databases. Pooled relative risk (RR) estimates were calculated using a random effects model, and subgroup analyses conducted across dementia subtypes. Results:Twelve studies were included, with a total of 16,200 participants. Considered concurrently, diabetes increased incident dementia risk an additional 35% for those with ɛ4 (RR = 1.35, 95% CI = 1.13–1.63). Similar patterns were observed for AD and vascular dementia. Conclusion:Interventions to prevent co-morbid diabetes, and diabetes-related complications and neuropathological changes, may be one way of modifying dementia risk in the vulnerable ɛ4 population

Physical activity and cognition in young-onset Parkinson's disease

Background A relationship has been observed between physical activity and cognition in older‐onset Parkinson's disease, as well as improvements in cognition after a physical activity intervention. To date, this has not been investigated in young‐onset Parkinson's disease (YOPD). Objectives To examine the baseline relationship between physical activity and cognition in YOPD; and to examine whether a physical activity intervention can improve cognition in YOPD. Methods Two interrelated online studies were conducted. In the first study, 132 participants with YOPD completed self‐reported measures of physical activity, and objective and subjective measures of cognition. A subset of 38 participants was then randomly allocated to either a six‐week physical activity intervention or control condition. Following the intervention, participants repeated the objective and subjective cognitive measures. Results No relationship was found between self‐reported physical activity and objective cognition; however, there was a relationship between physical activity and subjective cognition. Similarly, following the intervention subjective improvements were found for concentration, attention, and processing speed, but not for memory. Furthermore, medium effect sizes were evident for objective measures of processing speed and small‐medium effect sizes for planning and cognitive flexibility, although statistical significance was not reached. Conclusions In this first study investigating physical activity and cognition in YOPD, the results suggest that increased physical activity relates to improved processing speed and attention. Replication is recommended with a larger sample size. A longer, more intense physical activity manipulation and utilizing the study's strengths of online recruitment and intervention delivery are also recommended

Examination of the Feasibility, Acceptability, and Efficacy of the Online Personalised Training in Memory Strategies for Everyday Program for Older Adults: Single-Arm Pre-Post Trial

BackgroundMemory strategy training for older adults helps maintain and improve cognitive health but is traditionally offered face-to-face, which is resource intensive, limits accessibility, and is challenging during a pandemic. Web-based interventions, such as the Online Personalised Training in Memory Strategies for Everyday (OPTIMiSE) program, may overcome such barriers. ObjectiveWe report on OPTIMiSE’s feasibility, acceptability, and efficacy. MethodsAustralians aged ≥60 years reporting subjective cognitive decline participated in this single-arm pre-post web-based intervention. OPTIMiSE is a 6-module web-based program offered over 8-weeks with a 3-month booster. It has a problem-solving approach to memory issues, focusing on psychoeducation about memory and aging, knowledge and practice of compensatory memory strategies, and personalized content related to individual priorities. We examined the feasibility (recruitment, attrition, and data collection), acceptability (recommendation to others, suggestions for improvement, and withdrawal reasons), and efficacy (change in goal satisfaction, strategy knowledge and use, self-reported memory, memory satisfaction and knowledge, and mood; thematic content analysis of the most significant change; and the application of knowledge and strategies in daily life) of OPTIMiSE. ResultsOPTIMiSE was feasible, demonstrated by strong interest (633 individuals screened), a satisfactory level of attrition (158/312, 50.6%), and minimal missing data from those completing the intervention. It was acceptable, with 97.4% (150/154) of participants agreeing they would recommend OPTIMiSE, the main suggestion for improvement being more time to complete modules, and withdrawal reasons similar to those in in-person interventions. OPTIMiSE was also efficacious, with linear mixed-effects analyses revealing improvements, of moderate to large effect sizes, across all primary outcomes (all P<.001): memory goal satisfaction (Cohen d after course=1.24; Cohen d at 3-month booster=1.64), strategy knowledge (Cohen d after course=0.67; Cohen d at 3-month booster=0.72) and use (Cohen d after course=0.79; Cohen d at 3-month booster=0.90), self-reported memory (Cohen d after course=0.80; Cohen d at 3-month booster=0.83), memory satisfaction (Cohen d after course=1.25; Cohen d at 3-month booster=1.29) and knowledge (Cohen d after course=0.96; Cohen d at 3-month booster=0.26), and mood (Cohen d after course=−0.35; nonsignificant Cohen d at booster). Furthermore, the most significant changes reported by participants (strategy use, improvements in daily life, reduced concern about memory, confidence and self-efficacy, and sharing and shame busting with others) reflected the course objectives and were consistent with themes arising from previous in-person interventions. At the 3-month booster, many participants reported continued implementation of knowledge and strategies in their daily lives. ConclusionsThis feasible, acceptable, and efficacious web-based program has the potential to enable access to evidence-based memory interventions for older adults worldwide. Notably, the changes in knowledge, beliefs, and strategy use continued beyond the initial program. This is particularly important for supporting the growing number of older adults living with cognitive concerns. Trial RegistrationAustralian New Zealand Clinical Trials Registry ACTRN12620000979954; https://tinyurl.com/34cdantv International Registered Report Identifier (IRRID)RR2-10.3233/ADR-20025

The relationship between olfactory identification and memory and burden in Alzheimer's disease, mild cognitive impairment and healthy aging: a PiB-PET study

2 page(s

Olfactory Deficits and Amyloid-beta Burden in Alzheimer's Disease, Mild Cognitive Impairment, and Healthy Aging: A PiB PET Study

Olfactory deficits and increased amyloid-β (Aβ) burden are observed in people with amnestic mild cognitive impairment (aMCI); both factors may be predictive of Alzheimer's disease (AD). We explored whether olfactory identification is related to in vivo measures of Aβ burden using Pittsburgh Compound B (PiB) PET. Nineteen control, 24 aMCI, and 20 AD participants completed an olfactory identification task and underwent PiB PET scanning. Control participants performed better on olfactory identification and showed lower PiB binding than aMCI patients. There was a significant correlation between both factors when pooling all groups together but not when considering each group separately. In addition, the olfactory identification score did not differ between aMCI participants who were PiB-positive and those who were PiB-negative. We conclude that AD-related olfactory identification deficits are not directly related to Aβ burden.7 page(s

Olfactory Deficits and Amyloid-Beta Burden in Alzheimer's Disease,Mild Coginitve Impairment, and Healthy Aging:A PiB PET Study

Olfactory deficits and increased amyloid-β (Aβ) burden are observed in people with amnestic mild cognitive impairment (aMCI); both factors may be predictive of Alzheimer's disease (AD). We explored whether olfactory identification is related to in viv

Correlation of memory dysfunction and amyloid burden in mild cognitive impairment

1 page(s

Correlation between amyloid burden and memory impairment: A¹¹C-PIB PET cross sectional study

Objectives: Mild cognitive impairment (MCI) carries a high risk of conversion to Alzheimer's disease (AD). The relationship between brain beta-amyloid (A?) burden and cognitive function has not been explored in subjects with MCI. We examined this relationship using in-vivo amyloid-imaging tracer 11C-PIB. Methods: 32 healthy controls (HC) (age 71 � 7; MMSE >28), 35 MCI subjects (age 71 � 9; MMSE 26.8 � 2) and 40 subjects with mild to moderate AD (age 74 � 10; MMSE 21.7 � 4) underwent 11C-PIB PET. All subjects underwent MMSE and California Verbal Learning Test II (CVLT II). A? burden was quantified using Standardized Uptake Value normalized to cerebellar cortex (SUVR) 40-70 post-injection. The neocortical SUVR was used for analysis. Results: Neocortical SUVR was 1.40 � 0.33 in HC, 1.84 � 0.59 in MCI and 2.42 � 0.33 in AD and correlated negatively across all subjects with MMSE (r = -0.56, P < 0.001). When groups were analysed separately, only the MCI cohort showed a correlation with cognition (MMSE: r = -0.33, P < 0.05; CVLT: r = -0.53, P < 0.001). Cognitive performance did not correlate with level of PIB retention in other groups. At a SUVR threshold of 1.6 (the 75th percentile of HC), cortical PIB binding was present in 100% of AD, 60% of MCI and 23% of HC. In MCI, but not in HC, PIB positive subjects performed worse than PIB negative subjects on cognitive performance (CVLT II-long delay: 3.60 � 4.51 vs. 7.21 � 4.35; p = 0.026). Correlation between A? and memory impairment in MCI persisted after excluding the PIB negative subjects (CVLT r = -0.49, P < 0.01). Conclusions: Our data supports a pathogenic role for A? accumulation in AD by showing a relationship to mild cognitive impairment. This relationship is lost in later stages of disease as dementia develops suggesting a maximum or equilibrium level of A? plaque can be reached early in the pathological course of AD. These findings may have implications for anti-amyloid therapy.7 page(s