Evaluation of in vivo staging of amyloid deposition in cognitively unimpaired elderly aged 78-94.

Amyloid-beta (Aß) deposition is common in cognitively unimpaired (CU) elderly >85 years. This study investigated amyloid distribution and evaluated three published in vivo amyloid-PET staging schemes from a cognitively unimpaired (CU) cohort aged 84.9 ± 4.3 years (n = 75). SUV-based principal component analysis (PCA) was applied to 18F-flutemetamol PET data to determine an unbiased regional covariance pattern of tracer uptake across grey matter regions. PET staging schemes were applied to the data and compared to the PCA output. Concentration of p-tau181 was measured in blood plasma. The PCA revealed three distinct components accounting for 91.2% of total SUV variance. PC1 driven by the large common variance of uptake in neocortical and striatal regions was significantly positively correlated with global SUVRs, APOE4 status and p-tau181 concentration. PC2 represented mainly non-specific uptake in typical amyloid-PET reference regions, and PC3 the occipital lobe. Application of the staging schemes demonstrated that the majority of the CU cohort (up to 93%) were classified as having pathological amount and distribution of Aß. Good correspondence existed between binary (+/-) classification and later amyloid stages, however, substantial differences existed between schemes for low stages with 8-17% of individuals being unstageable, i.e., not following the sequential progression of Aß deposition. In spite of the difference in staging outcomes there was broad spatial overlap between earlier stages and PC1, most prominently in default mode network regions. This study critically evaluated the utility of in vivo amyloid staging from a single PET scan in CU elderly and found that early amyloid stages could not be consistently classified. The majority of the cohort had pathological Aß, thus, it remains an open topic what constitutes abnormal brain Aß in the oldest-old and what is the best method to determine that.

Scores Obtained from a Simple Cognitive Test of Visuospatial Episodic Memory Performed Decades before Death Are Associated with the Ultimate Presence of Alzheimer Disease Pathology.

BACKGROUND: Community- or population-based longitudinal studies of cognitive ability with a brain donation end point offer an opportunity to examine relationships between pathology and cognitive state prior to death. Discriminating the earliest signs of dementing disorders, such as Alzheimer disease (AD), is necessary to undertake early interventions and treatments. METHODS: The neuropathological profile of brains donated from The University of Manchester Longitudinal Study of Cognition in Normal Healthy Old Age, including CERAD (Consortium to Establish a Registry for Alzheimer's Disease) and Braak stage, was assessed by immunohistochemistry. Cognitive test scores collected 20 years prior to death were correlated with the extent of AD pathology present at death. RESULTS: Baseline scores from the Memory Circle test had the ability to distinguish between individuals who developed substantial AD pathology and those with no, or low, AD pathology. Predicted test scores at the age of 65 years also discriminated between these pathology groups. The addition of APOE genotype further improved the discriminatory ability of the model. CONCLUSIONS: The results raise the possibility of identifying individuals at future risk of the neuropathological changes associated with AD over 20 years before death using a simple cognitive test. This work may facilitate early interventions, therapeutics and treatments for AD by identifying at-risk and minimally affected (in pathological terms) individuals.

Location tracking: views from the older adult population.

BACKGROUND: there has been a rise in the use of social media applications that allow people to see where friends, family and nearby services are located. Yet while uptake has been high for younger people, adoption by older adults is relatively slow, despite the potential health and social benefits. In this paper, we explore the barriers to acceptance of location-based services (LBS) in a community of older adults. OBJECTIVE: to understand attitudes to LBS technologies in older adults. METHODS: eighty-six older adults used LBS for 1-week and completed pre- and post-use questionnaires. Twenty available volunteers from the first study also completed in-depth interviews after their experience using the LBS technology. RESULTS: the pre-use questionnaire identified perceptions of usefulness, individual privacy and visibility as predictive of intentions to use a location-tracking service. Post-use, perceived risk was the only factor to predict intention to use LBS. Interviews with participants revealed that LBS was primarily seen as an assistive technology and that issues of trust and privacy were important. CONCLUSION: the findings from this study suggest older adults struggle to see the benefits of LBS and have a number of privacy concerns likely to inhibit future uptake of location-tracking services and devices.

Exploring patterns of daily physical and sedentary behaviour in community-dwelling older adults.

BACKGROUND: recent evidence suggests that the interaction between periods of sedentary and activity behaviour is important for health; providing distinctive information to assessment of activity alone. This study quantified activity and sedentary behaviour in older, community-dwelling adults. METHODS: fifty-six community-dwelling older adults with an average age 79 (SD) years wore an ActivPAL accelerometer for 7 days and were assessed for a range of motor, cognitive and affective characteristics. Seven variables derived from accelerometry considered to represent four characteristics of habitual behaviour (volume, frequency, intensity and variability) were submitted to principal components factor analysis (PCA). Factor scores were retained and used as dependent variables in regression analysis. RESULTS: three significant orthogonal factors emerged from the PCA, accounting for 80% of the variance in test scores: 'walking behaviour' which accounted for 39% of variance in the model; 'sedentary behaviour' explaining 24.3% of total variance; and 'postural transitions' which accounted for 16.7% of total variance. For the regression analysis, younger age and lower body mass index (BMI) emerged as significant predictors of physical behaviour, explaining 36% of the total variance. For postural transitions, lower BMI was the unique contributor, explaining 15% of total variance. Significant predictors of sedentary behaviours were not identified. CONCLUSIONS: walking, sedentary and transitory behaviours are distinct from each other, and together explain daily function. Further research on a larger sample is indicated to explore the characteristics that explain these behaviours, in particular the interplay between sedentary behaviour and periods of physical activity.

The Effects of COVID-19 Lockdown on Health and Psychosocial Functioning in Older Adults Aged 70 and Over.

The COVID-19 pandemic led to a state-imposed lockdown in the UK; there are many psychosocial consequences of pandemics, with older adults potentially at an increased risk. The current study assessed psychosocial functioning in a sample of older adults in the UK with baseline data collected pre-lockdown and follow-up 12 weeks later during lockdown. Thus, allowing investigation of the effect of COVID-19 and associated lockdown on psychosocial well-being. Thirty-five older adults (Mean age = 76.06, sex = 12 males) participated in this repeated measures study. A final follow-up was then conducted post-lockdown to capture any factors that were viewed as helpful to well-being during lockdown. From pre- to during lockdown, perceived stress, well-being, depressive symptoms, mood disturbance and memory were all significantly worsened. There were significant improvements in self-reported physical health symptoms, social interaction, time spent engaging in physical activity and certain aspects of relationship quality. Follow-up showed that well-being, depression and mood were still negatively affected post-lockdown. Given the sample were all 'healthy' at baseline in comparison to established norms, there may be greater impairment in more vulnerable populations. Support for older populations is needed to mitigate the negative effects shown, particularly in light of the endurance of some of these effects post-lockdown.

Practice and drop-out effects during a 17-year longitudinal study of cognitive aging.

Interpretations of longitudinal studies of cognitive aging are misleading unless effects of practice and selective drop-out are considered. A random effects model taking practice and drop-out into account analyzed data from four successive presentations of each of two intelligence tests, two vocabulary tests, and two verbal memory tests during a 17-year longitudinal study of 5,899 community residents whose ages ranged from 49 to 92 years. On intelligence tests, substantial practice effects counteracted true declines observed over 3 to 5 years of aging and remained significant even with intervals of 7 years between successive assessments. Adjustment for practice and drop-out revealed accelerating declines in fluid intelligence and cumulative learning, linear declines in verbal free recall, and no substantial change in vocabulary. Socioeconomic status and basal levels of general fluid ability did not affect rates of decline. After further adjustment for demographics, variability between individuals was seen to increase as the sample aged.

Concordance of Cornell medical index self-reports to structured clinical assessment for the identification of physical health status.

Self-reported questionnaires are frequently used to assess health status in epidemiological studies. The Cornell medical index is one such tool used to determine the presence of physical and psychiatric illness but its accuracy and value have been questioned. In this study we have assessed the ability of the CMI to predict health status in two separate patient populations (n = 101, 88) by comparison to a structured medical assessment based on the SENIEUR protocol by two physicians. There was good agreement between medication use reported on the CMI and on medical assessment (k = 0.79; CI: 0.70-0.88). Accuracy of prediction of the CMI for specific medical conditions was good 89-99%. A threshold score from the CMI was not predictive of health as determined by the SENIEUR protocol. In our older populations, we conclude that the CMI accurately predicted health status. The determination of normal health by a threshold score was poorly predictive of heath status. Self-reported medication use was the best predictor of health status.

Do clever brains age more slowly? Further exploration of a nun result.

Recent epidemiological evidence suggests that individuals who have higher levels of mental ability in youth experience a slower cognitive decline as they grow old. In a sample of 3,263 Newcastle residents, average scores on a vocabulary test (Raven's 1965 'Mill Hill A') did not vary, while average scores on a test of fluid mental ability (the Heim, 1970, AH 4 (1) group intelligence test) sharply declined with age from 49 to 92 years. In young adults, Mill Hill A scores are good proxies for AH 4 (1) scores. This relationship allowed individuals' youthful AH 4 (1) test scores to be estimated from their current, unchanged, Mill Hill A scores so that age-related changes in AH 4 test scores over the adult life-span could be estimated and compared between high and low ability groups, men and women, and individuals of different levels of socio-economic advantage. The cross-sectional estimated rate of age-related decline in general mental ability was found to be the same for people of all levels of ability and socio-economic advantage, and not to differ between men and women.

Developing a self-reported comorbidity index to predict mortality of community-dwelling older adults.

Current common comorbidity measures have poor to moderate predictive validity of mortality of community-dwelling older adults. Hence, our aim is to develop a simpler resource-efficient self-reported comorbidity index in the prediction of survival. 113 older adults in Greater Manchester, United Kingdom attended a routine medical examination whereby information gathered was used to construct Charlson Comorbidity Index (CCI). They completed the Cornell Medical Index (CMI) questionnaire and reported the number of medication prescribed to them. We compared the ability of CCI, CMI, number of medication, age and sex to predict mortality of the sample over 7-year period using Cox-regression and Kaplan-Meier plot and rank test. None of the variables individually was significant when tested using either Cox-regression via ENTER method or Kaplan-Meier test. Remarkably, by means of forward step-wise Cox-regression, two variables emerged significant: (i) number of medicine (beta coefficient=0.229, SE=0.090 and p=0.011) and (ii) age (beta coefficient=0.106, SE=0.051 and p=0.037). We demonstrated that simple count of medication predicted mortality of community-dwelling older adults over the next 7 years more accurately than CMI or CCI. Further works involving a larger scale of subjects is needed for use in epidemiological study of survival where cost and resources are concerned.

Further analyses of the effects of practice, dropout, sex, socio-economic advantage, and recruitment cohort differences during the University of Manchester longitudinal study of cognitive change in old age.

A sample of 4,314 volunteers who, when first recruited, were aged from 41 to 93 years were quadrennially tested from 2 to 4 occasions during the next 4 to 20 years on the Cattell Culture Fair intelligence test, 2 tests of information-processing speed, the Wechsler Adult Intelligence Scale (WAIS) vocabulary test, and 3 memory tests. After significant effects of practice, sex, demographics, socio-economic advantage, and recruitment cohort had been identified and considered, performance on all tests declined with age. These age-related declines accelerated for the Cattell and WAIS, 2 tests of information speed, and 2 of the memory tests. For all tests individuals' trajectories of age-related change diverged with increasing age but, unexpectedly, were not affected by demographic factors. Practice gains from an initial experience of the cognitive tests remained undiminished as the interval before the second experience increased from 4 to 8 + years.