Cognitive reserve moderates relation between global cognition and functional status in older adults

Multimorbidity and Quality of Life: The Mediating Role of ADL, IADL, Loneliness, and Depressive Symptoms

Background and Objectives

The ubiquity of multimorbidity makes it crucial to examine the intermediary factors linking it with quality of life (QoL). The objective was to examine to what extent the association between multimorbidity and QoL was mediated by functional and emotional/mental health and how these mediation pathways differed by sociodemographic factors (age, gender, education, and financial strain).

Research Design and Methods

Data from Waves 4 to 8 of 36,908 individuals from the Survey of Health, Aging, and Retirement in Europe (SHARE) were included. Multimorbidity (exposure) was defined as having 2 or more chronic conditions. Mediators included limitations with (instrumental) activities of daily living (ADL and IADL), loneliness, and depressive symptoms. QoL (outcome) was assessed with the CASP-12 scale. Longitudinal model-based causal mediation analyses were performed to decompose the total association between multimorbidity and QoL into direct and indirect effects. Moderated mediation analyses tested for differences in mediation pathways by sociodemographic factors.

Results

Multimorbidity was significantly associated with lower QoL (direct effect: b = -0.66). This association was mediated by ADL limitations (percentage mediated 0.97%), IADL limitations (3.24%), and depressive symptoms (16.70%), but not by loneliness. The mediation pathways were moderated by age, education, financial strain, and gender.

Discussion and Implications

ADL, IADL, and depressive symptoms are crucial intermediary factors between multimorbidity and QoL in older European adults, with changing importance according to age, education, financial strain, and gender. The findings may help to increase the QoL of individuals with multimorbidity and redirect care efforts to these factors.

Research trends and hotspots of post-stroke cognitive impairment: a bibliometric analysis

Background: Post-stroke cognitive impairment (PSCI) is a major complication of stroke that affects more than one-third of stroke survivors, threatening their quality of life and increasing the risk of disability and death. Although various studies have described the etiology, epidemiology, and risk factors of PSCI, there are a limited number of comprehensive and accurate reports on research trends and hotspots in this field. Therefore, this review aimed to evaluate research trends, hotspots, and frontiers in PSCI using bibliometric analysis. Methods: We screened the literature spanning 20 years in the Web of Science Core Collection: Science Citation Index Expanded (SCI-Expanded) database from 1 January 2003 to 31 December 2022. We included all eligible literature reports based on our comprehensive search strategy, inclusion criteria, and exclusion criteria. The analysis of annual publications, countries/regions, institutions, journals, co-cited references, and keywords was conducted using CiteSpace and VOSviewer, and the hotspots and major findings of PSCI were summarized. Results: A total of 1,024 publications were included in this review. We found that the number of publications on PSCI increased annually. These publications were published in 75 countries or regions by over 400 institutions. Although Chinese institutions had the highest number of publications, their international influence was limited. The United States showed a strong influence in the field. The journal "Stroke" published the most publications (57) with a high impact factor and was considered the most co-cited journal. The most frequently cited references focused on the prevalence, incidence, neuropsychological assessment scales, criteria, and guidelines of PSCI. The strongest citation burst keywords for PSCI were "neurotrophic factor" and "synaptic plasticity", which were regarded as research focuses and research hotspots, respectively. Conclusion: This review provided a comprehensive summary of the literature of PSCI, identified the authoritative and frequently cited literature and journals, clarified the trends in PSCI research, and highlighted the hotspots in this field. Currently, studies on the mechanisms and treatment of PSCI are limited, and we hope that this review has effectively highlighted the research trajectory of PSCI and will lay the foundation for more innovative research in the future.

Association between Systemic Immune Inflammation Index and Cognitive Impairment after Acute Ischemic Stroke

Background and Aims: Post-stroke cognitive impairment (PSCI) is one of the major complications after ischemic stroke. PSCI has been shown to be associated with low-grade systemic inflammation. As a novel inflammatory marker, the systemic immune-inflammation (SII) index could reflect clinical outcomes in severe cardiovascular diseases. We therefore performed a prospective study to investigate the correlation between the SII index and the risk of PSCI in patients with ischemic stroke. Methods: We prospectively enrolled 254 patients with ischemic stroke with symptoms onset <72 h. The SII index was detected within 24 h after admission. The Montreal Cognitive Scale (MoCA) was utilized to evaluate cognitive function, and PSCI was defined as a MoCA score of <25 points. Results: During the 3-month follow-up, 70 participants (27.6%) had mild cognitive impairment and 60 (23.6%) had severe cognitive impairment. In binary logistic regression analysis, each one-standard deviation increase in the SII index was significantly associated with the prevalence of PSCI after adjusting for age, sex, and other confounders (odds ratio 2.341; 95% confidence interval, 1.439–3.809, p = 0.001). Similar significant findings were observed when SII was defined as a categorical variable. In addition, the multiple-adjusted spline regression model showed a linear association between the SII index and cognitive impairment (p = 0.003 for linearity). Conclusions: Our study indicated that an increased SII index was closely related to PSCI at 3 months in patients with ischemic stroke. Further research is required to evaluate the efficacy of inflammation management in these patients.

Longitudinal Predictors of Informant-Rated Everyday Function in Mild Cognitive Impairment

OBJECTIVE

To examine predictors of informant-reported everyday functioning in mild cognitive impairment (MCI) and relations between everyday function and conversion to dementia.

METHODS

Informants of participants (n = 2614) with mild cognitive impairment (MCI) were administered the Functional Activities Questionnaire (FAQ). Changes in dimensions of functional ability as determined by an exploratory factor analysis (EFA) were examined over 3 years and participant predictors of change were examined using multilevel modeling (MLM).

RESULTS

The FAQ consisted of 3 factors, multistep, finance, and memory/orientation daily tasks. Impairment in memory/orientation tasks was significantly higher than impairment in multistep tasks. Worse functioning was associated with greater depression, worse memory, worse speed/EF, higher years of education and identifying as White. There was variability in some of these associations with different FAQ factors. Impairments in financial and memory/orientation daily tasks predicted follow-up conversion to dementia.

CONCLUSIONS

Depression, speed/EF, and memory are consistently associated with domains of everyday functioning. Race, education, and age may be more variability associated with everyday functioning. Specific attention should be paid to subtle declines in the financial and memory/orientation domains as they may uniquely predict future dementia development. Depression may be a modifiable risk factor associated with functional impairment over time.

The moderating effect of cognitive reserve on cognitive function in patients with Acute Ischemic Stroke

Background

Recovery of cognitive function after stroke has inter-individual variability. The theory of cognitive reserve offers a potential explanation of the variability in cognitive function after stroke.

Objective

This study aimed to investigate the moderating effect of cognitive reserve on the relationship between the stroke severity and cognitive function after stroke.

Materials and methods

A total of 220 patients with Acute Ischemic Stroke (AIS) were recruited in 2021 from two stroke centers in Nanjing, China. The National Institutes of Health Stroke Scale (NIHSS) was used to assess stroke severity upon admission. Cognitive Reserve Index questionnaire (CRIq) and validated Montreal Cognitive Assessment, Changsha Version (MoCA-CS) were used to assess cognitive reserve and cognitive function within 7 days after stroke onset, respectively. A series of multivariate linear regression models were applied to test the moderating effect of cognitive reserve.

Results

Patients with a higher level of cognitive reserve had better cognitive function after stroke compared with those with a lower level of cognitive reserve (β = 0.074, p = 0.003). The interaction of NIHSS and cognitive reserve was statistically significant (β = −0.010, p = 0.045) after adjusting for some key covariates [e.g., age, marital status, Oxfordshire Community Stroke Project (OCSP) classification, Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification, cerebral vascular stenosis, diabetes and atrial fibrillation].

Conclusion

Cognitive reserve may help to buffer the effect of stroke-related pathology on cognitive decline in Chinese acute stroke patients. Enhancing cognitive reserve in stroke patients may be one of the potential strategies for preventing vascular dementia.

Factors Influencing Post-Stroke Cognitive Impairment in Patients with Type 2 Diabetes Mellitus

Objective

Type 2 diabetes mellitus (T2DM) and ischemic stroke, which are common diseases among older people, are closely related to cognitive impairment. This study aims to investigate the influencing factors of post-stroke cognitive impairment (PSCI) in patients with T2DM.

Methods

We enrolled 161 patients with T2DM who experienced acute ischemic stroke and were hospitalized in the Department of Neurology, Jinan Central Hospital, Shandong, China. Cognitive function was evaluated with the Montreal Cognitive Assessment scale. According to the results, patients were divided into three groups-the cognitively normal group, mild cognitive impairment group, and severe cognitive impairment group. We analyzed general demographic data, laboratory information, imaging data, the results of neuropsychological evaluation, and clinical features as well as influencing factors of PSCI in these patients and established a prediction model.

Results

The three groups of patients were significantly different in terms of age, education level, course of diabetes mellitus (DM), recurrent cerebral infarction (RCI), and other factors. RCI, course of DM, and glycated hemoglobin (HbA1c) were independent risk factors of PSCI in patients with T2DM, with odds ratio (95% confidence interval): 7.17 (2.09, 30.37), 5.39 (2.40, 14.59), and 3.89 (1.66, 10.04), respectively, whereas female, senior high school, serum albumin were protective factors: 0.28 (0.07, 0.95), 0.05 (0.01, 0.21), 0.20 (0.08, 0.42), respectively. Furthermore, we constructed a prediction model using sex, age, education level, RCI, DM course, HbA1c and serum albumin and obtained a receiver operating characteristic (ROC) curve. The area under the ROC curve is 0.966, suggesting the significant association of these influencing factors with PSCI in patients with T2DM.

Conclusion

In this study, the occurrence of PSCI in patients with T2DM was related to RCI, course of DM, and HbA1c, among other factors. Attention to influencing factors is needed in these patients for early diagnosis and timely intervention of cognitive impairment.

Pre-Morbid IQ Moderates the Relationship between Cognitive Performance and Performance-Based Functional Status in Older Adults

Objectives: The current study sought to evaluate the relationship between cognitive performance and Instrumental Activities of Daily Living (IADL) performance in a population of community dwelling older adults, and assess to what extent this relationship is moderated by cognitive reserve (Premorbid-IQ)Methods: 123 community-dwelling older adults completed a general cognitive assessment, a word-reading based premorbid-IQ estimate (PMIQE) measure, and the performance-based Direct Assessment of Functional Status, Revised (DAFS-R). Moderated regression analysis was used to assess the influence of PMIQE on the relationship between cognitive performance and IADLs.Results: There was a significant main effect of cognitive performance on IADLs, and no main effect of PMIQE on functional IADLs. There was a significant moderating effect of PMIQE on the relationship between cognitive performance and IADLs performance, such that at higher levels of PMIQE, cognitive performance scores became slightly less predictive of weaknesses in IADLs.Conclusions: Results suggest that for individuals with high reserve, assessment of cognitive performance alone may not be robust a predictor of IADLs functioning.Clinical implications: In estimating functional abilities as a consequence of cognitive performance, consideration should be given to premorbid-IQ/cognitive reserve.

Cognitive reserve, cognition, and real-world functioning in MCI: A systematic review and meta-analysis

OBJECTIVE

To synthesize quantitatively the mild cognitive impairment (MCI) literature with respect to the relationship between cognitive reserve and neuropsychological and functional outcomes.

METHOD

Participants with a diagnosis of MCI (total n = 7,871; 53% female) were included in this random-effects meta-analysis. Neuropsychological measures were combined into composite scores (e.g., overall cognitive functioning, screening measures, memory, language, visuospatial, attention/processing speed/working memory, executive functioning, and motor functioning). Measures assessing real-world abilities were combined into an activities of daily living (ADL) composite.

RESULTS

Nearly all neuropsychological composite values were significantly correlated with education, with effect sizes ranging from small to moderate. The effect between overall neuropsychological functioning and occupation was weak and varied by cognitive domain. For cognitively stimulating leisure activity, only overall neuropsychological functioning demonstrated a significant relationship, with a weak effect size (r = .16). In contrast, ADLs were most strongly associated with leisure experience (r = .27), with a negligible relationship with education (r = 0.08) and occupation (r = 0.09).

CONCLUSIONS

Of the cognitive reserve proxies examined in this study, participation in leisure activity had the largest magnitude of effect size with ADL functioning. This was in stark contrast to the negligible relationship found for education and occupation. Although education has been widely considered the most important cognitive reserve proxy with respect to cognition, this work questions whether other lifestyle factors may play a more important role in preserving real world functioning.

The influence of cognitive reserve in the protection of the cognitive status after an acquired brain injury: A systematic review

BACKGROUND

Cognitive Reserve (CR) hypothesis was introduced to account for the variability in cognitive performance of patients with similar degrees of brain injury or pathology. The individual variability of CR is modulated by the interaction of innate capacities and exposures throughout life, which can act as protectors against neuropathology's clinical effects. Individuals with higher CR appear to have better cognitive performance after a brain injury. The present review aimed to identify and map the scientific evidence available in literature regarding CR's influence in protecting the cognitive status after an Acquired Brain Injury (ABI).

METHOD

A systematic review was performed for published studies until October 2020 in PubMed, Scopus, and CINAHL electronic databases. Studies regarding CR's influence in protecting the cognitive status after an ABI were included in this review. The Newcastle-Ottawa Scale was used to assess risk of bias in the included studies. This systematic review was recorded in the International Prospective Register of Systematic Reviews (PROSPERO) under the number CRD42021236594.

RESULTS

Twenty-one studies published between 2003 and 2020 were selected and analyzed. The literature analysis showed that CR has a positive effect on cognitive status after an ABI. Various proxies were used to estimate CR, including estimated premorbid IQ, education, occupation attainment, socioeconomic status, leisure activities, bilingualism, and social integration. CR proxies constitute a set of variables that may have a significant influence on cognitive status. Higher CR levels were associated with lower cognitive impairment after an ABI.

CONCLUSIONS

Although more research is necessary for a complete understanding of CR's impact on cognition, the synthesis of these studies confirmed that there is evidence on the beneficial impact of CR on cognitive status after an ABI. These findings support CR's cognitive status role following an ABI and may provide additional information for prognosis and rehabilitation plans.

Increasingly capable at the ripe old age? Cognitive abilities from 2004 to 2013 in Germany, Spain, and Sweden

Background

Life expectancy is increasing in most high-income countries, but gains in life years are maximized if spent in good health and if cognitive abilities are maintained until old age. Age-related decline of cognitive abilities does nevertheless occur, but the pace of decline is decisive. This was the starting point for our study that aims to examine cohort effects of cognitive aging in women and men in Germany, Spain and Sweden by analyzing changes from 2004 to 2013 by estimating cohort effects within age groups starting from the age of 50 years.

Methods

A cohort study was conducted that was based on data of the surveys 2004 (N = 6,081) and 2013 (N = 8,650) from the Survey of Health, Ageing and Retirement in Europe (SHARE). The analyses were based on data of female and male respondents aged 50 years and older. Age-specific means of verbal fluency and delayed recall from the German, Spanish and Swedish samples were the cognitive domains considered in the study.

Results

In both domains of cognitive ability the achievements in the later surveys were higher than in the earlier ones. This was found in all countries, abut achievement levels increased markedly in the German and the Spanish samples, while the scores of the Swedish samples were not significantly different.

While the highest scores were found for Sweden, Germany ranked in the middle and the lowest scores were found in the Spanish samples. Over time, the scores of the German samples approached those of Sweden.

Conclusions

From the first to the second survey, improvements of older adults’ cognitive abilities were found for all countries considered. This may indicate improvements of the underlying educational systems, but also increasingly stimulating general living conditions.

Impact of Cognitive Reserve and Premorbid IQ on Cognitive and Functional Status in Older Outpatients

The study aimed to investigate cross-sectionally the associations of cognitive reserve (CR) and premorbid IQ with cognitive and functional status in a cohort of older outpatients. Additionally, we evaluated the association of CR and premorbid IQ with the worsening of patients' cognitive status at one-year follow-up. We originally included 141 outpatients (mean age 80.31 years); a telephone-based cognitive follow-up was carried out after one year, including 104 subjects (mean age 80.26 years). CR (β = 0.418), premorbid IQ (β = 0.271) and handgrip strength (β = 0.287) were significantly associated with the MMSE score. The cognitive worsening at follow-up was associated with lower CR, lower MMSE score, reduced gait speed and frailty exhibited at baseline. Univariate linear regressions showed that CR was associated with handgrip strength (β = 0.346), gait speed (β = 0.185), autonomy in basic (β = 0.221) and instrumental (β = 0.272) daily activities, and frailty (β = -0.290); premorbid IQ was significantly associated with autonomy in instrumental daily activities (β = 0.211). These findings highlight the need for integrating CR and premorbid IQ with physical and motor measures when appraising predictors of cognitive decline in the elderly population. The study also newly extends the link of CR and premorbid IQ to the functional status in older adults.

Functional brain changes associated with cognitive training in healthy older adults: A preliminary ALE meta-analysis

Accumulating evidence suggests that cognitive training (CT) programs may provide healthy older adults (OAs) with cognitive benefits that are accompanied by alterations in neural activity. The current review offers the first quantitative synthesis of the available literature on the neural effects of CT in healthy aging. It was hypothesized that OAs would evidence increased and decreased neural activations across various challenging CTs, and that these effects would be observed as significantly altered clusters within regions of the frontoparietal network (FPN). Online databases and reference lists were searched to identify peer-reviewed publications that reported assessment of neural changes associated with CT programs in healthy OAs. Among the 2097 candidate studies identified, 14 studies with a total of 238 participants met inclusionary criteria. GingerALE software was used to quantify neural effects in a whole-brain analysis. The activation likelihood estimation technique revealed significant increases in activation following CT in the left hemisphere middle frontal gyrus, precentral gyrus, and posterior parietal cortex, extending to the superior occipital gyrus. Two clusters of diminished neural activity following CT were identified within the right hemisphere middle frontal gyrus and supramarginal gyrus, extending to the superior temporal gyrus. These results provide preliminary evidence of common neural effects of different CT interventions within regions of the FPN. Findings may inform future investigations of neuroplasticity across the lifespan, including clinical applications of CT, such as assessing treatment outcomes.

Predictors of Cognitive Impairment After Stroke: A Prospective Stroke Cohort Study

BACKGROUND

Post-stroke cognitive impairment (PSCI) significantly affects stroke survivors' quality of life and rehabilitation. A risk model identifying cognitive decline at admission would help to improve early detection and management of post-stroke patients.

OBJECTIVE

To develop a new clinical risk score for ischemic stroke survivors in predicting 6-12 months PSCI.

METHODS

We prospectively enrolled 179 patients diagnosed with acute ischemic stroke within a 7-day onset. Data were analyzed based on baseline demographics, clinical risk factors, and radiological parameters. Logistic regression and area under the receiver operating curve (AUROC) were used to evaluate model efficiency.

RESULTS

One hundred forty-five subjects completed a 6-12-month follow-up visit, and 77 patients (53.1%) were diagnosed with PSCI. Age (β= 0.065, OR = 1.067, 95% CI = 1.016-1.120), years of education (β= -0.346, OR = 0.707, 95% CI = 0.607-0.824), periventricular hyperintensity grading (β= 1.253, OR = 3.501, 95% CI = 1.652-7.417), diabetes mellitus (β= 1.762, OR = 5.825, 95% CI = 2.068-16.412), and the number of acute nonlacunar infarcts (β= 0.569, OR = 1.766, 95% CI = 1.243-2.510) were independently associated with 6-12 month PSCI, constituting a model with optimal predictive efficiency (AUC = 0.884, 95% CI = 0.832-0.935).

CONCLUSIONS

The optimized risk model was effective in screening stroke survivors at high risk of developing 6-12 months PSCI in a simple and pragmatic way. It could be a potential tool to identify patients with a high risk of PSCI at an early stage in clinical practice after further independent external cohort validation.

CHA2DS2-VASc Stroke Risk Index and Executive Functioning in Older Adults

OBJECTIVE

CHA2DS2-VASc is a stroke risk classification system developed to improve the precision of stroke risk classification. The current study examined the validity of CHA2DS2-VASc in a sample of healthy older adults using executive function measures of processing speed, working memory, and cognitive flexibility that are sensitive to cerebrovascular risk factors.

METHODS

Participants included 51 community-dwelling, healthy older adults (ages 53-86) recruited from both the community and cardiology clinics. CHA2DS2-VASc was utilized as a measure of stroke risk. Measures of executive functioning and processing speed included the Paced Auditory Serial Addition Test (PASAT), Delis-Kaplan Executive Function System (DKEFS) Number-Letter Switching, and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Coding.

RESULTS

CHA2DS2-VASc scores significantly predicted scores on the PASAT, DKEFS Number-Letter Switching, and RBANS Coding, such that greater stroke risk was associated with poorer performances on tests of executive functioning and processing speed. These relationships were observed over and above the potential influence of educational attainment and symptoms of depression.

CONCLUSION

Significant relations between stroke risk classification and performance on several measures of executive functioning provide support for a wider and more generalized use of CHA2DS2-VASc with healthy older adults. These findings further highlight the importance of early identification and treatment of stroke risk factors associated with cognitive decline. Findings suggest that CHA2DS2-VASc is a practical and useful tool for patients and their providers in the early detection of stroke risk and development of individualized treatment plans.

Trends in Risk of Limitations in Instrumental Activities of Daily Living Over Age in Older Persons With and Without Multiple Chronic Conditions

Background

To investigate trends over age by comorbidity status for the risk of limitations in individual activities of daily living for community-living older persons.

Methods

A longitudinal population-based study was conducted in 9,319 community-living Dutch persons aged 60 years and older. Self-reported multiple chronic conditions (MCC) and nine instrumental activities of daily livings (IADLs) were assessed in 15 studies of the Dutch National Care for the Elderly Program (TOPICS-MDS). Risks of limitations in IADLs, odds ratios (per 5 years), and rate ratios (per 5 years) were calculated with mixed logistic and negative binomial regression models with age as the underlying timescale, stratified by number of MCC (no, 1–2, ≥ 3 MCC), and corrected for confounders.

Results

At inclusion, the number of IADL limitations was highest for the “≥3 MCC” group (2.00 interquartile range [1.00–4.00]) and equal for “no MCC” or “1–2 MCC” (1.00 interquartile range [0.00–2.00]). Trends of individual IADLs depicted a higher risk in IADL limitation with increasing age over 2 years of follow-up, except for handling finances for the “no MCC” group. The longitudinal age effect on IADL limitations varied subject to MCC, being strongest for the “no MCC” group for most IADLs; grooming and telephone use were almost unaltered by age and MCC.

Conclusion

We observed a decline in IADL functioning with increasing age over 2 years of follow-up in persons with and without MCC. The impact of MCC on IADL decline varied per IADL activity.

Education Differentially Buffers Cognitive Performance in Black and White Older Adults

OBJECTIVES

Given that black American older adults are more likely to have lower educational attainment and perform worse on cognitive tests than white Americans, we examined whether increased education would confer greater cognitive advantage to black Americans on measures of global and specific domains of cognitive function.

METHODS

The sample included 522 community-dwelling older adults from a larger study. An analysis of covariance was conducted with race and education as between-participant factors and global cognition as the dependent variable. A multivariate analysis of covariance was conducted with five cognitive domains (immediate memory, visuospatial/constructional ability, language, attention, and delayed memory) as the dependent variables.

RESULTS

Significant main effects indicated that black Americans, F(1,516) = 29.18, p < .001, and individuals with less education, F(1,516) = 44.93, p < .001, evidenced lower cognitive functioning, controlling for age and overall health status, and the interaction term reached statistical significance, F(1,516) = 7.95, p = .005. The impact of education on global cognitive function for black participants was more than twice as large (Cohen's d = 1.30) than for white participants (Cohen's d = .52). There was a significant race × education interaction for the cognitive domain of attention (p < .001) and a composite measure of non-memory domains (i.e., language, visuospatial/constructional, and attention; p < .001).

DISCUSSION

Our findings suggest that educational attainment is particularly important for black Americans with respect to global cognitive function, attention, and non-memory domains.

The Association of Cognitive Reserve in Chronic-Phase Functional and Neuropsychological Outcomes Following Traumatic Brain Injury

OBJECTIVE

Examine the association of cognitive reserve (CR) factors (estimated premorbid intelligence quotient [IQ], years of education, and occupational attainment) and traumatic brain injury (TBI) severity with functional and neuropsychological outcomes 1 to 5 years following TBI.

PARTICIPANTS

Patients with mild (N = 58), moderate (N = 25), or severe (N = 17) TBI.

MAIN MEASURES

Cognitive reserve factors (estimated premorbid IQ, years of education, and occupational attainment); neuropsychological test battery; Glasgow Outcome Scale-Extended; Short Form-36 Health Survey.

ANALYSES

Spearman-Brown correlations, linear regression models, and analyses of covariance were used to analyze the relation between CR factors and outcome measures.

RESULTS

Analyses revealed significant relations between estimated premorbid IQ and neuropsychological outcomes (P < .004): California Verbal Learning Test, Wechsler Adult Intelligence Scale-Fourth Edition working memory, Booklet Category Test, Trail Making Test B, and Grooved Pegboard Test. There was also a significant correlation between estimated premorbid IQ and Wechsler Adult Intelligence Scale-Fourth Edition processing speed. Years of education had significant relations with California Verbal Learning Test and Wechsler Adult Intelligence Scale-Fourth Edition working memory and processing speed scores. There were significant differences between TBI severity groups and performance on the Trail Making Test A, Grooved Pegboard Test, and Finger Tapping Test.

CONCLUSIONS

Cognitive reserve factors may be associated with outcomes following TBI. Additional alternatives to TBI severity are needed to help guide rehabilitative planning postinjury.

Neurocompensatory Effects of the Default Network in Older Adults

The hemispheric asymmetry reduction in older adults (HAROLD) is a neurocompensatory process that has been observed across several cognitive functions but has not yet been examined in relation to task-induced relative deactivations of the default mode network. The present study investigated the presence of HAROLD effects specific to neural activations and deactivations using a functional magnetic resonance imaging (fMRI) n-back paradigm. It was hypothesized that HAROLD effects would be identified in relative activations and deactivations during the paradigm, and that they would be associated with better 2-back performance. Forty-five older adults (M age = 63.8; range = 53-83) were administered a verbal n-back paradigm during fMRI. For each participant, the volume of brain response was summarized by left and right frontal regions of interest, and laterality indices (LI; i.e., left/right) were calculated to assess HAROLD effects. Group level results indicated that age was significantly and negatively correlated with LI (i.e., reduced left lateralization) for deactivations, but positively correlated with LI (i.e., increased left lateralization) for activations. The relationship between age and LI for deactivation was significantly moderated by performance level, revealing a stronger relationship between age and LI at higher levels of 2-back performance. Findings suggest that older adults may employ neurocompensatory processes specific to deactivations, and task-independent processes may be particularly sensitive to age-related neurocompensation.

Emotional and social characteristics of stroke patients with low verbal memory

BACKGROUND

Cognitive deficits, especially problems with memory observed after stroke often coexist with patients' experience of difficulties in everyday life situations.

AIMS

The purposes of the study were to explore the relationships between verbal memory, emotional functioning and social competence in stroke patients, and to examine the emotional and social condition of stroke patients with low verbal memory.

METHODS

Ninety-five participants were assessed with the Rey Auditory Verbal Learning Test, the Neuropsychology Behavior and Affect Profile, and the Social Competency Questionnaire. The participants' relatives (N = 95) also took part in the study evaluating patients' emotional and social functioning.

RESULTS

Stroke patients with low verbal memory had higher scores in depression, indifference, and inappropriateness than the patients with normal memory. They also obtained higher scores in the self-reported intimacy and lower scores in objectively assessed social exposition than controls.

DISCUSSION

It is worth considering patients' relationships with relatives that evolve after stroke, especially when the patients experience cognitive difficulties in gaining new information. Collecting verbal information seems to be important for the feeling of effectiveness in some dimensions of elders' social functioning.

CONCLUSIONS

Because the social engagement may be treated as protective factor in the course of recovery we would recommend that during rehabilitation more attention should be paid to emotional and social functioning of stroke patients with low verbal memory.

Functional Reserve: Experience Participating in Instrumental Activities of Daily Living is Associated with Gender and Functional Independence in Mild Cognitive Impairment

BACKGROUND

Gender differences in instrumental activities of daily living (IADLs) in mild cognitive impairment (MCI) and Alzheimer's disease may be explained by gender differences in IADL involvement.

OBJECTIVE

We introduce a novel theoretical construct, termed functional reserve, and empirically examine gender differences in IADL experience as a proxy of this reserve.

METHODS

We cross-sectionally examined men (n = 502) and women (n = 340) with MCI from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Demographic factors, depressive symptoms, neuropsychological scores, and IADL experience were included as independent variables and total Functional Activities Questionnaire (FAQ) scores as the dependent variable. Regression analyses were performed on the full cohort and stratified by gender to identify differential predictive relationships for men and women.

RESULTS

Gender was associated with total FAQ (p < 0.05) until adjusting for IADL experience. Furthermore, the combination of cognitive measures accounted for the most variance in functional dependence (12% explained, p < 0.001), although IADL experience was the most important single variable (4.8% explained, p < 0.001). Stratification by gender revealed that IADL experience accounted for 6.6% of the variance in FAQ score in men (p < 0.001) but only 2.4% in women (p = 0.001); however, the interaction between gender and experience was not statistically significant.

DISCUSSION

A small effect of men showing greater functional dependence in MCI may be explained by lower IADL experience. Additionally, IADL experience was associated with superior functioning in all analyses, potentially through increased functional reserve. This concept of functional reserve may have implications for identifying individuals at risk for IADL dependence, preventing or delaying decline, and potentially treating functional impairment.

Subtle changes in daily functioning predict conversion from normal to mild cognitive impairment or dementia: an analysis of the NACC database

BACKGROUND

There are relatively small but observable changes in functional ability in those without Mild cognitive impairment (MCI) or dementia. The present study seeks to understand whether these individuals go on to develop MCI or dementia by assessing the association between baseline Functional Activities Questionnaire (FAQ) and conversion independent and after adjustment for cognitive tests.

METHODS

The NACC database was used to conduct the analysis of which 7,625 participants were initially identified as having more than one visit and who were cognitively normal at their first visit. Cox proportional hazards were used to fit three models that controlled for executive and non-executive cognitive domains. A similar model was used to assess the effect of FAQ subcategories on conversion.

RESULTS

Of these individuals, 1,328 converted to either MCI or dementia by visit 10. Converters had a total visit 1 FAQ score significantly higher than non-converters indicating more functional impairment at baseline. After adjustment for cognitive tests, the association between visit 1 FAQ and subsequent conversion was not attenuated. Doing taxes, remembering dates, and traveling were individually identified as significant predictors of conversion.

CONCLUSIONS

The FAQ can be used as an indirect measure of functional ability and is associated with conversion to MCI or dementia. There is a selective and significant association between changes in financial ability and conversion that is in accordance with other research of financial capacity.

Correlates of cognitive functioning in independent elderly patients discharged home from the emergency department after a minor injury

BACKGROUND

The objective of this study was to explore correlates of cognitive functioning of older adults visiting the emergency department (ED) after a minor injury.

METHODS

These results are derived from a large prospective study in three Canadian EDs. Participants were aged ≥ 65 years and independent in basic activities of daily living, visiting the ED for minor injuries and discharged home within 48 hours (those with known dementia, confusion, and delirium were excluded). They completed the Montreal Cognitive Assessment (MoCA). Potential correlates included sociodemographic and injury variables, and measures of psychological and physical health, social support, mobility, falls, and functional status.

RESULTS

Multivariate analyses revealed that male sex, age ≥ 85 years, higher depression scores, slower walking speed, and self-reported memory problems were significantly associated with lower baseline MoCA scores.

CONCLUSIONS

These characteristics could help ED professionals identify patients who might need additional cognitive evaluations or follow-ups after their passage through the ED. Obtaining information on these characteristics is potentially feasible in the ED context and could help professionals alter favorably elderly's trajectory of care. Since a significant proportion of elderly patients consulting at an ED have cognitive impairment, the ED is an opportunity to prevent functional and cognitive decline.

Predictors for vascular cognitive impairment in stroke patients

BACKGROUND

Around two thirds stroke patients may suffer from vascular cognitive impairment (VCI). Our previous study has validated the NINDS-CSN harmonization standard for VCI diagnosis in Chinese. In this study, we aimed to investigate the predictors for VCI in Chinese post-stroke patients.

METHODS

We compared epidemiological, clinical, and neuroimaging data (number, size and location of acute infarcts and lacunes, severities of white matter hyperintensities and brain atrophy) between stroke patients with and without VCI. Univariate and logistic regression analyses were utilized to determine VCI predictors.

RESULTS

Fifty-six consecutive patients (age, 63.8 ± 8.3 years; female, 37.5%) were recruited at a mean interval of 7.1 months after stroke onset, and 31 (55.4%) patients were diagnosed with VCI based on a validated 60-min neuropsychological battery. VCI patients were older (p = 0.023), less educated (p = 0.001), more likely to be female (p < 0.001), had a recurrent stroke (p = 0.028), and described higher apathy (p = 0.022) and worse pre-stroke cognition (p = 0.048) than cognitively normal patients. Lower educational level (adjusted odds ratio [OR] 0.750, 95% confidence interval [CI], 0.573-0.981; p = 0.035), female sex (adjusted OR 8.288, 95% CI, 1.522-45.113; p = 0.014), recurrent stroke (adjusted OR 11.327, 95% CI, 1.335-96.130, p = 0.026), and global cortical atrophy (adjusted OR 5.730, 95% CI, 1.128-29.101, p = 0.035) were independently associated with VCI in post-stroke patients.

CONCLUSIONS

Lower education, female sex, recurrent stroke and global cortical atrophy were associated with VCI in Chinese stroke patients.

The role of cognitive reserve and memory self-efficacy in compensatory strategy use: A structural equation approach

INTRODUCTION

The use of compensatory strategies plays an important role in the ability of older adults to adapt to late-life memory changes. Even with the benefits associated with compensatory strategy use, little research has explored specific mechanisms associated with memory performance and compensatory strategies. Rather than an individual's objective memory performance directly predicting their use of compensatory strategies, it is possible that some other variables are indirectly influencing that relationship. The purpose of this study was to: (a) examine the moderating effects of cognitive reserve (CR) and (b) evaluate the potential mediating effects of memory self-efficacy on the relationship between objective memory performance and compensatory strategy use.

METHOD

Two structural equation models (SEM) were used to evaluate CR (latent moderator model) and memory self-efficacy (mediator model) in a sample of 155 community-dwelling older adults over the age of 55.

RESULTS

The latent variable moderator model indicated that CR was not substantiated as a moderator variable in this sample (p = .861). However, memory self-efficacy significantly mediated the association between objective memory performance and compensatory strategy use (β = .22, 95% confidence interval, CI [.002, .437]). More specifically, better objective memory was associated with lower compensatory strategy use because of its relation to higher memory self-efficacy.

CONCLUSIONS

These findings provide initial support for an explanatory framework of the relation between objective memory and compensatory strategy use in a healthy older adult population by identifying the importance of an individual's memory perceptions.

Cortical thickness in frontoparietal and cingulo-opercular networks predicts executive function performance in older adults

OBJECTIVE

This study examined the relationship between cortical thickness in executive control networks and neuropsychological measures of executive function.

METHOD

Forty-one community-dwelling older adults completed an MRI scan and a neuropsychological battery including 5 measures of executive function.

RESULTS

Factor analysis of executive function measures revealed 2 distinct factors: (a) Complex Attention Control (CAC), comprised of tasks that required immediate response to stimuli and involved subtle performance feedback; and (b) Sustained Executive Control (SEC), comprised of tasks that involved maintenance and manipulation of information over time. Neural networks of interest were the frontoparietal network (F-P) and cingulo-opercular network (C-O), which have previously been hypothesized to relate to different components of executive function, based on functional MRI studies, but not neuropsychological factors. Linear regression models revealed that greater cortical thickness in the F-P network, but not the C-O network, predicted better performance on the CAC factor, whereas greater cortical thickness in the C-O network, but not the F-P network, predicted better performance on the SEC factor.

CONCLUSIONS

The relationship between cortical thickness and performance on executive function measures was characterized by a double dissociation between the thickness of cortical regions hypothesized to be involved in executive control and distinct executive processes. Results indicate that fundamentally different executive processes may be predicted by cortical thickness in distinct brain networks.

Delay and probability discounting as candidate markers for dementia: an initial investigation

The present study investigated delay discounting and probability discounting-behavioral economic indices of impulsivity and risk proneness, respectively-in 39 healthy older adults and 25 older adults with mild cognitive impairment (MCI). Relative to the healthy group, it was hypothesized that older adults with MCI would display greater levels of impulsivity, risk proneness, and response inconsistency. The MCI group was found to display a unique delay discounting profile characterized by increasing impulsivity with decreasing reward magnitude, such that cognitively impaired older adults were significantly more impulsive than healthy controls at the small reward magnitude. The two groups exhibited similar levels of probability discounting, though older adults with MCI were significantly less consistent in their risk preferences. The present findings shed light onto decision-making in pre-dementia disease stages and suggest that discounting performance holds potential to complement early diagnostic instruments, likely due to pathophysiological processes in relevant brain regions.