Are cognitively intact seniors with subjective memory loss more likely to develop dementia?

Clusters of cognitive performance predict long-term cognitive impairment in elderly patients with subjective memory complaints and healthy controls

INTRODUCTION

Patients with subjective memory complaints (SMC) may include subgroups with different neuropsychological profiles and risks of cognitive impairment.

METHODS

Cluster analysis was performed on two datasets (n: 630 and 734) comprising demographic and neuropsychological data from SMC and healthy controls (HC). Survival analyses were conducted on clusters. Bayesian model averaging assessed the predictive utility of clusters and other biomarkers.

RESULTS

Two clusters with higher and lower than average cognitive performance were detected in SMC and HC. Assignment to the lower performance cluster increased the risk of cognitive impairment in both datasets (hazard ratios: 1.78 and 2.96; Plog-rank: 0.04 and <0.001) and was associated with lower hippocampal volumes and higher tau/amyloid beta 42 ratios in cerebrospinal fluid. The effect of SMC was small and confounded by mood.

DISCUSSION

This study provides evidence of the presence of cognitive clusters that hold biological significance and predictive value for cognitive decline in SMC and HC.

HIGHLIGHTS

Patients with subjective memory complaints include two cognitive clusters. Assignment to the lower performance cluster increases risk of cognitive impairment. This cluster shows a pattern of biomarkers consistent with incipient Alzheimer's disease pathology. The same cognitive cluster structure is found in healthy controls. The effect of memory complaints on risk of cognitive decline is small and confounded.

Development of a Revised Version of Subjective Memory Complaints Questionnaire in Taiwan: A Preliminary Study

OBJECTIVES

Research has suggested that subjective memory complaints (SMC) are predictive of cognitive decline in cases of Alzheimer's disease; however, multidimensional characteristics of SMC make it difficult to formulate causal links. The Subjective Memory Complaints Questionnaire (SMCQ) has proven effective in capturing the nature of SMC. In this study, we developed a revised version of SMCQ (SMCQ-R) with corresponding normative data for application in Taiwan.

METHODS

This study recruited 100 cognitively normal participants (> 45 years) stratified according to demographic characteristics. Assessments were performed to evaluate test-retest reliability, criterion-related validity, and construct validity of SMCQ-R. SMCQ-R scores of 20 matched patients with mild cognitive impairment (MCI) were also compared with those of normal participants to test construct validity.

RESULTS

Reliability of SMCQ-R was satisfactory (0.81-0.95). Factor analysis revealed a three-factor structure: everyday memory problems (EMP), recent severe memory problems (RSMP), and long-term memory problems (LTMP). EMP and RSMP scores were negatively associated with objective cognitive function (r = -.20 to .39). Depressive symptoms were positively associated with all factors (r = .23-.33). Age was positively associated with total (b = 0.09, p < .05) and EMP scores (b = 0.06, p < .01). MCI patients obtained higher scores (p < .05) on all subscales. SMCQ-R scores discriminated between normal and MCI individuals (area under the curve = 0.77). This study established a norm based on scores adjusted to control for effects of age.

CONCLUSIONS

SMCQ-R has sound psychometric properties and could potentially be used as a tool to assess SMC in clinical settings.

The role of disability and depressive symptoms in the relation between objective cognitive performance and subjective cognitive decline

BACKGROUND

Subjective cognitive decline (SCD) and subjective memory decline (SMD) are common among older people. Evidence linking SCD and SMD with cognitive and memory impairment is inconsistent. Moreover, little is known about the associations of SCD and SMD with disability. We aimed to explore the associations of SCD and SMD with objective cognitive and memory performance, disability, and depressive symptoms.

MATERIALS AND METHODS

In a cross-sectional study we conducted face to face interviews in a randomized sample of people aged ≥65 years living in the Canton of Ticino, southern Switzerland, between May 2021 and April 2022. We measured subjective cognitive decline with the MyCog, a subsection of the Subjective Cognitive Decline Questionnaire (SCD-Q); cognitive functioning with the Community Screening Instrument for Dementia; memory with the consortium to establish a registry for alzheimer's disease (CERAD) 10-word list learning task; and disability and depressive symptoms with the world health organization disability assessment schedule 2.0 (WHO-DAS 2.0) and the Euro-Depression (EURO-D) scales, respectively.

RESULTS

Of the 250 participants 93.6% reported at least one cognitive difficulty, and 40.0% SMD. Both SCD and SMD were associated with poorer objective cognitive/memory performance, and independently with greater disability, and more depressive symptoms. But in participants with high disability and depressive symptoms subjective and objective cognition were no longer associated. Disability fully mediated the associations of poorer objective cognitive and memory performance with subjective cognitive and memory decline.

CONCLUSION

Routine clinical assessments of cognitive function should include formal enquires about SCD and SMD, and also account for disability and depressive symptoms.

Dementia-Free Older Adults with Subjective Cognitive Impairment Show Lower Mood and No Deficits of Spontaneous Memory Retrieval

The aim of the present study was to investigate whether spontaneous retrieval deficits could be found in individuals with Subjective Cognitive Impairment (SCI). The sample consisted of 52 participants over 65 years of age (mean age = 76.00; SD = 7.48) with 11 males. We asked 26 individuals with SCI and 26 individuals without SCI to perform a prospective memory (PM) task that had previously demonstrated spontaneous retrieval deficits in individuals with Mild Cognitive Impairment. The results did not demonstrate the expected differences in a PM task based on spontaneous retrieval [t(50) = -.05; p = .964, d = .01]. However, participants' mood did predict their subjective memory complaints (β = -.51; p < .001) and their subjective assessment of their future memory performance (r = -.38; p < .01). The findings are in line with numerous studies which have shown that SCI is more related to mood disturbance than to objective cognitive functioning.

Subjective Cognitive Decline: Level of Risk for Future Dementia and Mild Cognitive Impairment, a Meta-Analysis of Longitudinal Studies

Subjective Cognitive Decline (SCD) in older adults has been identified as a risk factor for dementia, although the literature is inconsistent, and it is unclear which factors moderate progression from SCD to dementia. Through separate meta-analyses, we aimed to determine if SCD increased the risk of developing dementia or mild cognitive impairment (MCI). Furthermore, we examined several possible moderators. Longitudinal studies of participants with SCD at baseline, with data regarding incident dementia or MCI, were extracted from MEDLINE and PsycINFO. Articles were excluded if SCD occurred solely in the context of dementia, MCI, or as part of a specific disease. Pooled estimates were calculated using a random-effects model, with moderator analyses examining whether risk varied according to SCD definition, demographics, genetics, recruitment source, and follow-up duration. Risk of study bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool. 46 studies with more than 74,000 unique participants were included. SCD was associated with increased risk of developing dementia (HR = 1.90, 95% CI 1.52-2.36; OR = 2.48, 95% CI 1.97-3.14) and MCI (HR = 1.73, 95% CI 1.18-2.52; OR = 1.83, 95% CI 1.56-2.16). None of the potential moderating factors examined influenced the HR or OR of developing dementia. In contrast, including worry in the definition of SCD, younger age, and recruitment source impacted the OR of developing MCI, with clinic samples demonstrating highest risk. SCD thus represents an at-risk phase, ideal for early intervention, with further research required to identify effective interventions for risk reduction, and cognitive-behavioural interventions for cognitive management. PROSPERO, protocol number: CRD42016037993.

Histidine Tautomeric Effect on the Key Fragment R3 of Tau Protein from Atomistic Simulations

Self-assembly of hyperphosphorylated tau proteins into neurofibrillary tangles (NFT) is a hallmark of Alzheimer's disease. Previous studies suggest that the tau monomer may play an important role in NFTs formation in two general categories: inert (M_i) monomer and seed-competent (M_s) monomer. In the current study, replica-exchange molecular dynamics (REMD) were performed to investigate the effect of histidine tautomerism on the structures of a key fragment (R3) of tau protein and the transformation between different conformations. Based on the simulation results, we propose the histidine tautomerism hypothesis for tau protein misfolding. Histidine tautomerism greatly expands the conformational library, which triggers the emergence of conformations with higher aggregation tendency. Moreover, the conversions existing in both isomers and conformations may cause protein misfolding to occur more readily.

Cognitive Functions Predict Trajectories of Sleepiness Over 10 Years: A Population-Based Study

BACKGROUND

Excessive daytime sleepiness is associated with chronic disorders of aging and mortality. Because longitudinal data are limited on the development of sleep disturbances and cognitive changes in older adults, we investigated the demographic, clinical, and cognitive predictors of self-reported daytime sleepiness over a period of 10 years.

METHODS

We jointly modeled latent trajectories over time of sleepiness, cognitive domains, and informative attrition and then fit models to identify cognitive trajectories and baseline characteristics that predicted the trajectories of sleepiness.

RESULTS

Three latent trajectory groups were identified: emerging sleepiness, persistent sleepiness, and consistently low daytime sleepiness accounting for attrition in all groups. Compared with low sleepiness, emerging sleepiness was significantly associated with declining attention and subjective memory complaints; persistent sleepiness was associated with lower baseline scores in all cognitive domains, declining language trajectory, and more subjective memory complaints.

CONCLUSIONS

These findings suggest that persistent sleepiness and emerging daytime sleepiness are associated with cognitive decline and multiple morbidities, albeit more subtly in emerging daytime sleepiness. Furthermore, these data suggest that change in the cognitive domain of attention and subjective memory complaints may be early indicators of future sleep disturbance.

Personality determinants of subjective executive function in older adults

Objectives: Problems in subjective executive function, the perceived cognitive control of mental processes for goal-directed behavior, may indicate cognitive impairment in older adulthood. Although, previous studies highlight the importance of personality on objective cognitive performance, no studies clarify their role with subjective executive function. To inform methods of early identification of cognitive impairment, this study explored how temperament and personality traits account for problems in subjective executive function.Method: The current project examined the associations between temperament and personality on subjective executive function across two samples of community-dwelling older adults (65+ years, n₁ = 25, n₂ = 50). Both studies measured subjective executive function (Behavioral Rating Inventory of Executive Function-Adult) and separately administered scales on temperament (Adult Temperament Questionnaire) and personality (Big Five Inventory).Results: Concerning temperament, older adults higher in negative affect endorsed greater difficulty in subjective executive function. Regarding personality traits, older adults with higher neuroticism and lower conscientiousness reported higher difficulty in subjective executive function.Conclusion: Findings enhance our understanding of subtle cognitive changes and may aid in early detection. In particular, distressful inclinations were associated with more reported problems in executive function whereas problem-solving tendencies were inversely related. Future work should examine if enhanced negativity coupled with analytical disengagement predicts problems in subjective executive function over time.

Altered prefrontal cortex responses in older adults with subjective memory complaints and dementia during dual-task gait: An fNIRS study

People with cognitive impairments show deficits during physical performances such as gait, in particular during cognitively challenging conditions (i.e. dual-task gait [DTG]). However, it is unclear if people at risk of dementia, such as those with subjective memory complaints (SMC), also display gait and central deficits associated with DTG. In this study, we investigated the effects of single- and dual-task gait (STG and DTG), on left prefrontal cortex (PFC) activation in elderly people with subjective memory complaints (SMC) and Dementia. A total of 58 older adults (aged 65-94 years; 26 Healthy; 23 SMC; 9 Dementia) were recruited. Gait spatiotemporal characteristics (i.e. stride velocity and length) were assessed using an instrumented walkway during STG and DTG. Single-channel functional near-infrared spectroscopy over the left PFC was used to measure changes in oxyhaemoglobin (O₂ Hb) during gait. Stride velocity and length during STG (all p < .05) and DTG (all p < .000) were significantly impaired in people with Dementia compared to Healthy and SMC individuals. No differences were observed between Healthy and SMC. For STG, a greater increase in O₂ Hb (p < .05) was observed in those with Dementia compared to the Healthy and SMC, while no differences were observed between Healthy and SMC. A significant increase and decline in O₂ Hb was observed during DTG in the SMC and Dementia groups, respectively, compared to Healthy. Our findings indicate an altered pattern of cerebral haemodynamic response of the left PFC in DTG in people with SMC and Dementia, which may suggest that central changes precede functional impairments in people with SMC.

Distribution and clinical impact of apolipoprotein E4 in subjective memory impairment and early mild cognitive impairment

The apolipoprotein E (APOE) e4 allele is the most common genetic variant associated with Alzheimer’s disease (AD). We sought to investigate the distribution of APOE genotypes across the full clinical AD spectrum including AD, late-stage amnestic mild cognitive impairment (L-aMCI), early-stage aMCI (E-aMCI), subjective memory impairment (SMI), and controls. We prospectively recruited 713 AD patients, 735 aMCI patients, 575 SMI patients, and 8,260 individuals as controls. The frequency of the APOE e4 allele revealed an ordered fashion in the AD (30.8%), L-aMCI (24.0%), E-aMCI (15.1%), SMI (11.7%), and control (9.1%) groups. APOE e3/e4 and e4/e4 genotype frequencies also appeared in an ordered fashion in the AD group (39.1% of e3/e4 and 10.9% of e4/e4), as well as the L-aMCI (28.3% and 9.4%), E-aMCI (22.3% and 3.7%), SMI (18.3% and 1.9%), and control (15.1% and 0.8%) groups. In the comparisons of APOE e3/e3 vs. e3/e4 genotypes, all patient groups had a higher frequency of APOE e3/e4 relative to the control group. Relative to the SMI and E-aMCI groups, the AD and L-aMCI groups had higher frequency of the APOE e3/e4 genotype, and the AD group had a higher frequency relative to the L-aMCI group. However, there was no significant difference between the E-aMCI and SMI groups. In our longitudinal data, APOE e4 carrier showed a steeper incline slope in a clinical dementia rating sum of boxes (CDR-SB) score than APOE e4 non-carrier in SMI (B = 0.0066, p = 0.0104), E-aMCI (B = 0.0313, p < 0.0001), and L-aMCI (B = 0.0178, p = 0.0007). APOE e4 carrier showed a steeper decline slope in the CDR-SB than APOE e4 non-carrier in AD (B = − 0.0309, p = 0.0003). These findings suggest that E-aMCI and SMI are associated with a similarly increased frequency of the APOE e4 allele compared to controls, suggesting a greater genetic risk for AD and the importance of monitoring the allele more closely.

Impact of A2V Mutation and Histidine Tautomerism on Aβ42 Monomer Structures from Atomistic Simulations

The self-assembly of amyloid-β (Aβ) peptides into senile plaques in the brain is a hallmark of Alzheimer's disease (AD) pathology. Mutation and histidine tautomerism are considered intrinsic origins in the accumulation of Aβ. As a first step toward understanding the impact of A2V mutation and histidine tautomerism on the Aβ42 isoform, we performed replica-exchange molecular dynamics (REMD) simulations to investigate the effects of histidine tautomerism on the structural properties of A2V Aβ42 peptides. There are generally more β-sheet and less α-helix secondary structures in A2V Aβ42 monomers than in WT Aβ42, implying a higher aggregation tendency in A2V Aβ42, which is consistent with previous studies. The current research will help develop the histidine tautomerism hypothesis of misfolded protein aggregation and eventually elucidate the pathogenesis of AD.

Motoric cognitive risk syndrome: Integration of two early harbingers of dementia in older adults

Dementia is characterized by a long preclinical phase that may last years to decades before the onset of mild cognitive impairment. Slow gait speed and subjective memory complaint commonly co-occur during this preclinical phase, and each is a strong independent predictor of cognitive decline and dementia. Motoric cognitive risk (MCR) syndrome is a pre-dementia syndrome that combines these two early harbingers of dementia. The risk of cognitive decline or dementia is stronger for MCR than for either slow gait speed or subjective memory complaint alone. Slow gait speed and subjective memory complaint have several common risk factors: cardiovascular disease, diabetes mellitus, abnormal cortisol profiles, low vitamin D levels, brain atrophy with decreased hippocampal volume, and increased deposition of beta-amyloid in the brain. The underlying pathogenesis of MCR remains poorly understood. Metabolomics and proteomics have great potential to provide new insights into biological pathways involved in MCR during the long preclinical phase preceding dementia.

Functional cognitive disorders: a systematic review

Cognitive symptoms are common, and yet many who seek help for cognitive symptoms neither have, nor go on to develop, dementia. A proportion of these people are likely to have functional cognitive disorders, a subtype of functional neurological disorders, in which cognitive symptoms are present, associated with distress or disability, but caused by functional alterations rather than degenerative brain disease or another structural lesion. In this Review, we have systematically examined the prevalence and clinical associations of functional cognitive disorders, and related phenotypes, within the wider cognitive disorder literature. Around a quarter of patients presenting to memory clinics received diagnoses that might indicate the presence of functional cognitive disorders, which were associated with affective symptoms, negative self-evaluation, negative illness perceptions, non-progressive symptom trajectories, and linguistic and behavioural differences during clinical interactions. Those with functional cognitive disorder phenotypes are at risk of iatrogenic harm because of misdiagnosis or inaccurate prediction of future decline. Further research is imperative to improve diagnosis and identify effective treatments for functional cognitive disorders, and better understanding these phenotypes will also improve the specificity of diagnoses of prodromal degenerative brain disease.

Association between childhood socioeconomic status and subjective memory complaints among older adults: results from the Japan Gerontological Evaluation Study 2010

BACKGROUND

Subjective memory complaints (SMC) have been suggested as an early marker of mild cognitive impairment and dementia. However, there is a paucity of evidence on the effects of early life conditions on the development of SMC in old age. This study is aimed at investigating the association between childhood socioeconomic status (SES) and SMC in community-dwelling older adults.

METHODS

We used the data of the Japan Gerontological Evaluation Study, a population-based cohort study of people aged 65 years or older enrolled from 28 municipalities across Japan. Childhood SES and SMC in everyday life were assessed from the self-report questionnaire administered in 2010 (n = 16,184). Poisson regression was performed to determine their association, adjusted for potential confounders and life-course mediators and examined cohort effects.

RESULTS

We identified SMC in 47.4% of the participants. After adjusting for sex, age, and number of siblings, low and middle childhood SES were associated with 29% (prevalence ratio [PR]: 1.29, 95% confidence interval [CI]: 1.22, 1.36) and 10% higher prevalence of SMC (PR: 1.10, 95%CI: 1.04, 1.17), respectively, compared with high childhood SES (p for trend <.001). The interaction terms between childhood SES and age groups were not statistically significant.

CONCLUSION

Childhood SES is significantly associated with SMC among community-dwelling older adults. Efforts to minimize childhood poverty may diminish or delay the onset of SMC and dementia in later life.

Predicting current and future anxiety symptoms in cognitively intact older adults with memory complaints

OBJECTIVES

Memory complaints are a common concern for older adults and may co-occur with anxiety symptoms. Although both memory complaints and anxiety are associated with heightened cognitive decline risk, little is known about how these symptoms develop over time. The purpose of this study was to examine the differential concurrent and longitudinal relationships among anxiety symptoms and two types of memory complaints in cognitively intact older adults.

METHODS/DESIGN

The current study sample was drawn from two longitudinal, nationally representative datasets, the National Health and Aging Trends Study (NHATS) and the Health and Retirement Study (HRS). Cognitively intact older adults aged 65 and over were included, representing six (n = 5069; NHATS) and two (n = 5284; HRS) waves of data, respectively. Using multilevel linear modeling, we tested bidirectional relationships between anxiety and two types of memory complaints: current rating of memory performance and perceived memory decline.

RESULTS

Concurrent associations between anxiety symptoms and memory complaints were found in both datasets: At times when current memory performance was rated more poorly or perceived memory decline was reported, anxiety symptoms tended to be higher, and vice versa. A longitudinal relationship was identified in NHATS such that perceived memory decline, and not current memory rating, predicted future anxiety symptoms.

CONCLUSION

This study provides a better understanding of the relationships between memory complaints and anxiety symptoms over time. Cognitively intact older adults with perceived memory decline are at greater risk for current as well as future anxiety symptoms.

Interactions between subjective memory complaint and objective cognitive deficit on memory performances

Background

Subjective memory complaint (SMCs) is a common trait amongst older population. The subjective cognition about their memory could depend on objective cognition. The aim of the current study was to examine the interaction between subjective memory cognition (i.e., SMC) and objective cognition on cognitive functions in participants from older generation.

Methods

A total of 219 patients, 181 normal control (NC) patients and 38 patients with mild cognitive impairment (MCI), were examined through standardized and comprehensive clinical evaluation and neuropsychological assessment. The Subjective Memory Complaints Questionnaire was used to assess SMCs along with five cognitive tasks were used to evaluate cognitive decline over following areas: verbal memory, visuospatial memory, attention, fluency, and language.

Results

The results of 2 × 2 two-way analysis of variance (ANOVA) showed that there were significant interactions between SMCs and cognitive status (NC, MCI) on memory performances. NC with SMCs showed significantly lower performance in verbal memory and visuospatial memory compared to NCs without SMCs. Conversely, no effect was observed in the MCI group.

Conclusion

There are interactions between subjective cognition (i.e., SMC) and objective cognition (i.e., cognitive status) on memory performances in older adults. The roles of SMCs on memory performances should be interpreted with older adults’ objective cognitive status.

Social Participation and Cognitive Decline Among Community-dwelling Older Adults: A Community-based Longitudinal Study

Objective

To examine whether social participation (SP) by older individuals is associated with cognitive decline (CD).

Method

Participants were community-dwelling older adults aged 65 or older with both independent activities of daily living and normal cognitive performance at baseline (2,768 men and 3,325 women). CD was evaluated using the Cognitive Performance Scale. Logistic regression analysis stratified by gender was used to examine CD in relation to SP, with nonparticipation as reference. Age, family, body mass index, pensions, comorbidities, medications, alcohol, smoking, depression, self-rated health, and instrumental activities of daily living were used as covariates.

Results

During the 3-year follow-up, 16.7% of eligible participants reported CD. After covariate adjustments, greater social group participation was associated with CD prevention for women only. Lessened negative CD effects were found in respondents active in these particular types of social outlets: neighborhood associations (odds ratio = 0.81, 95% confidence interval = 0.66-0.99) and local event groups (0.79, 0.63-0.99) for men, and hobby groups (0.70, 0.54-0.91) and volunteer groups (0.66, 0.45-0.96) for women.

Discussion

Our results suggest that greater social group participation prevents CD in women, while the beneficial effect of each type of SP on cognition differs between genders. Determining which types of social groups are best for community-dwelling older people's participation based on gender may help them maintain their cognitive functioning abilities.

Is brain connectome research the future frontier for subjective cognitive decline? A systematic review

OBJECTIVE

We performed a systematic literature review on Subjective Cognitive Decline (SCD) in order to examine whether the resemblance of brain connectome and functional connectivity (FC) alterations in SCD with respect to MCI, AD and HC can help us draw conclusions on the progression of SCD to more advanced stages of dementia.

METHODS

We searched for studies that used any neuroimaging tool to investigate potential differences/similarities of brain connectome in SCD with respect to HC, MCI, and AD.

RESULTS

Sixteen studies were finally included in the review. Apparent FC connections and disruptions were observed in the white matter, default mode and gray matter networks in SCD with regards to HC, MCI, and AD. Interestingly, more apparent connections in SCD were located over the posterior regions, while an increase of FC over anterior regions was observed as the disease progressed.

CONCLUSIONS

Elders with SCD display a significant disruption of the brain network, which in most of the cases is worse than HC across multiple network parameters.

SIGNIFICANCE

The present review provides comprehensive and balanced coverage of a timely target research activity around SCD with the intention to identify similarities/differences across patient groups on the basis of brain connectome properties.

Mitochondria- and Oxidative Stress-Targeting Substances in Cognitive Decline-Related Disorders: From Molecular Mechanisms to Clinical Evidence

Alzheimer's disease (AD) is the most common form of dementia affecting people mainly in their sixth decade of life and at a higher age. It is an extensively studied neurodegenerative disorder yet incurable to date. While its main postmortem brain hallmarks are the presence of amyloid-β plaques and hyperphosphorylated tau tangles, the onset of the disease seems to be largely correlated to mitochondrial dysfunction, an early event in the disease pathogenesis. AD is characterized by flawed energy metabolism in the brain and excessive oxidative stress, processes that involve less adenosine triphosphate (ATP) and more reactive oxygen species (ROS) production respectively. Mitochondria are at the center of both these processes as they are responsible for energy and ROS generation through mainly oxidative phosphorylation. Standardized Ginkgo biloba extract (GBE), resveratrol, and phytoestrogens as well as the neurosteroid allopregnanolone have shown not only some mitochondria-modulating properties but also significant antioxidant potential in in vitro and in vivo studies. According to our review of the literature, GBE, resveratrol, allopregnanolone, and phytoestrogens showed promising effects on mitochondria in a descending evidence order and, notably, this order pattern is in line with the existing clinical evidence level for each entity. In this review, the effects of these four entities are discussed with special focus on their mitochondria-modulating effects and their mitochondria-improving and antioxidant properties across the spectrum of cognitive decline-related disorders. Evidence from preclinical and clinical studies on their mechanisms of action are summarized and highlighted.

Psychometric Properties Of The Persian Version Of The Memory Impact Questionnaire In Older Adults

BACKGROUND AND AIM

Memory impairment in the elderly has a high prevalence and can affect their performance, interactions and quality of life. A valid and reliable questionnaire is required to investigate the changes in the memory of the elderly. The aim of this study was to investigate the psychometric properties of the Persian version of the Memory Impact Questionnaire (MIQ) in the elderly.

METHODS

In this methodological study, 361 elderly people (181 people for exploratory factor analysis and 180 people for confirmatory factor analysis) were selected via convenience sampling. This questionnaire was translated based on the World Health Organization's (WHO) guidelines. Construct validities were assessed through exploratory and confirmatory factor analyses. Its reliability was also assessed using Cronbach's alpha coefficient.

RESULTS

In the exploratory factor analysis, three factors of lifestyle restrictions, positive coping, and negative emotion were extracted that were able to explain 54.04% of the total variance of the impact of memory change in the elderly. Confirmatory factor analysis confirmed the goodness of fit of the three-factor model of MIQ (RMSEA: 0.083; GFI: 0.97; NFI: 0.94; IFI: 0.97; PNFI: 0.86; AGFI: 0.75). The reliability of the "lifestyle restrictions", "negative emotion" and "positive coping" factors was found to be 0.89, 0.74, and 0.67, respectively, using Cronbach's alpha coefficient.

CONCLUSION

The Persian version of the MIQ is simple and practical and has acceptable reliability and validity that can be used to measure memory changes in the Iranian elderly.

Subjective Cognitive Decline Prediction of Mortality: Results from the Einstein Aging Study

BACKGROUND

The relation of pre-dementia stages to mortality has not been fully explored. Previous work examining subjective cognitive decline (SCD) and mortality is limited and mixed regarding methods used and consistency of findings.

OBJECTIVE

To examine SCD and mortality in a longitudinal, community-based cohort, using item response theory (IRT) methodology to form a composite SCD measure. Also, to assess whether this relationship was independent of clinical cognitive status.

METHODS

The Einstein Aging Study is a diverse longitudinal cohort of adults aged ≥70. SCD items were extracted from baseline CERAD questionnaires and a composite score was formed using IRT methodology. A total of 1,741 participants with complete data were clinically diagnosed as cognitively normal, or as having amnestic mild cognitive impairment (aMCI), nonamnestic mild cognitive impairment (naMCI), or dementia. 645 deaths occurred over a period of 8,912 person-years of follow-up. Cox proportional hazard models predicted time to death adjusting for covariates.

RESULTS

A one standard deviation unit increase in level of SCD was associated with >20% higher risk of mortality. However, when models were adjusted for clinical cognitive status, the association was no longer significant. Both dementia and aMCI predicted mortality. Furthermore, when analyses focused only on those without cognitive impairment, SCD level did not predict mortality.

CONCLUSIONS

The association of SCD with mortality may be due to the association of SCD with clinical cognitive status. Thus, SCD may be used as a community-based screen to initially identify those with cognitive impairment who may be at greatest risk for death.

Exaggerated reaction to novelty as a predictor of incipient cognitive decline among community-dwelling older adults

OBJECTIVE

The ability to detect covert markers of incipient cognitive decline among older adults before cognitive decline becomes overtly evident on traditional cognitive tests represents an important topic of research. Exaggerated reactions to novelty, reflected in novelty-induced increases in action planning latencies ("novelty effect"; NE) and low openness to experience (openness), have been previously associated with incipient cognitive decline among older adults who appeared cognitively normal at baseline. The purposes of the present study were to extend prior research on the utility of these markers by examining whether (a) NE and openness each predict cognitive change uniquely, and (b) whether these indices predict cognitive change above and beyond measures of memory, executive functions, processing speed/efficiency, premorbid IQ, and depressive symptoms.

METHOD

Sixty-one cognitively normal community-dwelling older adults were administered a battery of tests assessing the relevant constructs at baseline and one-year follow up. Changes in cognitive status were assessed using the Demetia Rating Scale, 2nd Edition, NE was assessed using the Push-Turn-Taptap task (an electronic motor sequence learning task), and openness using the NEO Personality Inventory-Revised. The Test of Premorbid Functioning, and subtests from Repeatable Battery for the Assessment of Neuropsychological Status, Delis-Kaplan Executive Function System, and Wechsler Adult Intelligence Scale, 4th Edition, were used for additional assessment of baseline cognition. Depressive symptoms were assessed using the Geriatric Depression Scale.

RESULTS

Results confirmed our hypothesis that both NE and openness contribute to prediction of cognitive change beyond baseline cognition and depressive symptoms, but none of the covariates (i.e., depression, executive functions, processing efficiency, or memory) themselves contributed to the model. NE and openness each contributed unique variance and were independent of each other.

CONCLUSIONS

Openness and NE have the potential to provide evidence-based methods for estimating risk of future cognitive change in persons with currently normal standardized test scores.

Memory Complaints and Cognitive Decline: Data from the GUIDAGE Study1

BACKGROUND

Subjective cognitive decline (SCD) may be a very early symptom of Alzheimer's disease (AD) and may be associated with a cognitive decline in a cognitively normal population. The McNair and Kahn Scale was used to assess memory complaints in the GuidAge study.

OBJECTIVE

Our objectives were to examine if the McNair and Kahn Scale can predict cognitive decline and to screen which (if any) of the question(s) of this scale would better predict this cognitive decline.

METHODS

The GuidAge study was a phase III, multicenter, randomized, double blind, placebo-controlled study. Individuals aged 70 years and older, without cognitive impairment (Clinical Dementia Rate (CDR = 0)) at baseline who had spontaneously reported SCD were included in this study. The 20-item version of the McNair and Kahn Scale was used to assess SCD and a standardized neuropsychological assessment was used to assess the cognitive status.

RESULTS

1,307 patients with SCD and with CDR = 0 at baseline were included. During the 5 years of follow-up, 519 patients showed cognitive decline. Incidence of aggravation score of CDR was 13.40% person years (95% CI [12.24-14.56]). Results showed a significant relationship between the McNair and Kahn Scale score and decline in cognitive performance (HR 1.012; 95% CI [1.002-1.021]; p = 0.0156). Among the 20 items, 5 were statistically significant to predict cognitive decline after adjustment.

CONCLUSION

SCD is a promising indicator of memory impairment. Our study found that using the McNair and Kahn scale can predict cognitive decline. A 5-item version of this scale could be used to screen patients in clinical practice and in clinical research.

Prevalence, Risk Factors, and Complaints Screening Tool Exploration of Subjective Cognitive Decline in a Large Cohort of the Chinese Population

BACKGROUND

Substantial studies have reported the prevalence and the affecting factors of subjective cognitive decline (SCD). The complaints screening scale has also been used for probing. However, little is known in China.

OBJECTIVE

To investigate the prevalence and risk factors of SCD, and explore an SCD complaints screening scale in China.

METHODS

Stratified cluster random sampling was conducted. 2,689 residents aged 60-80 years completed questionnaire 1. 814 residents were included for clinical and neuropsychological evaluations. Two standards were used to make the diagnosis of mild cognitive impairment (MCI) and SCD, and a preliminary screening rate comparison was carried out. Finally, we assessed the risk factors of SCD and the correlation between the SCD-questionnaire 9 (SCD-Q9) and the Auditory Verbal Learning Test-Long Delay Free Recall (AVLT-LR).

RESULTS

1) Standard 1 (ADNI2): the prevalence of SCD was 18.8% (95% CI = 14.7-22.9%) and zero conformed to six criteria (SCD plus). 2) Standard 2 (Jak/Bondi): the prevalence of SCD was 14.4% (95% CI = 10.7-18.1%). 3) Standard 1 had a relatively higher "false" positive rate, whereas Standard 2 had higher "false" negative rate. 4) Age, low education, fewer close friends, and daily drinking were independent risk factors for SCD progressing to MCI. 5) Total points of SCD-Q9 were negatively correlated to the value of AVLT-LR.

CONCLUSIONS

The prevalence of SCD is high in the ShunYi District in Beijing, China. Age, low education, less social support, and daily drinking are independent risk factors. The brief SCD-Q9 can be used as a reference.

The ERICA Score: An MR Imaging-based Visual Scoring System for the Assessment of Entorhinal Cortex Atrophy in Alzheimer Disease

Purpose To establish and evaluate a visual score focused on entorhinal cortex atrophy (ERICA), as the entorhinal cortex is one of the first brain structures affected in Alzheimer disease (AD). Materials and Methods In this retrospective study, ERICA was visually evaluated with magnetic resonance imaging (2009-2016). First, a four-point ERICA score was developed by using data in 48 consecutive subjects (20 patients with AD and 28 control subjects). Then, in the main analysis, ERICA and the standard medial temporal lobe atrophy (MTA) scores were determined in an independent cohort of 60 patients suspected of having AD (mean age, 69.4 years; range, 46-86 years) and in 60 age-matched patients with subjective cognitive decline (SCD) (mean age, 72.4 years; range 50-87 years). Score performances were evaluated with κ statistics, receiver operating characteristic analysis, t tests, and analysis of variance according to the Standards for Reporting of Diagnostic Accuracy Studies. Results Patients with AD had higher MTA scores (mean, 2.13) and ERICA scores (mean, 2.05) than patients with SCD (P < .001). An ERICA score of 2 or greater achieved a higher diagnostic accuracy (91%) than the MTA score (74%), with a sensitivity of 83% versus 57% and a specificity of 98% versus 92% in discriminating dementia caused by AD from SCD (P < .001). The ERICA score was correlated with amyloid β 42/40 ratio (ρ = -0.54, P < .001) and with cerebrospinal fluid tau (ρ = 0.35, P = .001) and p-tau (ρ = 0.31, P = .004). In multivariable linear regression analysis, ERICA was associated with verbal learning and recall (β = -.40 and -.41), nonverbal recall (β = -.28), and cued recall (β = -.41, P ≤ .002 for all). Conclusion An ERICA score of 2 or greater indicates probable AD with high diagnostic accuracy. ^© RSNA, 2018 Online supplemental material is available for this article.

Screening Ability of Subjective Memory Complaints, Informant-Reports for Cognitive Decline, and Their Combination in Memory Clinic Setting

OBJECTIVE

This study aimed to compare the accuracy of subjective memory complaints, informant-reports for cognitive declines, and their combination for screening cognitive disorders in memory clinic setting.

METHODS

One-hundred thirtytwo cognitively normal (CN), 136 mild cognitive impairment (MCI), and 546 dementia who visited the memory clinic in the Seoul National University Hospital underwent standardized clinical evaluation and comprehensive neuropsychological assessment. The Subjective Memory Complaints Questionnaire (SMCQ) and the Seoul Informant Report Questionnaire for Dementia (SIRQD) were used to assess subjective memory complaints and informant-reports for cognitive declines, respectively.

RESULTS

Both SMCQ and SIRQD showed significant screening ability for MCI, dementia, and overall cognitive disorder (CDall: MCI plus dementia) (screening accuracy: 60.1-94.6%). The combination of SMCQ and SIRQD (SMCQ+SIRQD) was found to have significantly better screening accuracy compared to SMCQ alone for any cognitive disorders. SMCQ+SIRQD also significantly improved screening accuracy of SIRQD alone for MCI and CDall, but not for dementia.

CONCLUSION

Our findings suggest that the combined information of both subjective memory complaints and informant-reports for cognitive declines can improve MCI screening by each individual information, while such combination appears not better than informant-reports in regard of dementia screening.

Changes in cognitive function and brain glucose metabolism in elderly women with subjective memory impairment: a 24-month prospective pilot study

OBJECTIVES

Subjective memory impairment (SMI) may precede mild cognitive impairment (MCI) stage and would offer an earlier therapeutic opportunity than MCI would. However, it is not clear whether complaints of forgetfulness are truly reflective of objective memory dysfunction or of impairments in other cognitive domains. The aim of this current longitudinal study was to investigate changes in various cognitive functions and in regional cerebral metabolic rate of glucose (rCMRglc) among elderly women with SMI.

MATERIALS AND METHODS

Clinical evaluation, comprehensive neuropsychological test, and ¹⁸ F-fluoro-2-deoxyglucose positron emission tomography scans were conducted on 24 women with SMI at the baseline and 24-month follow-up. Changes in the cognitive domain scores and rCMRglc were assessed, and the relationships between them were analyzed.

RESULTS

All participants stayed in SMI all the way till the follow-up, not converted to MCI or dementia. A significant reduction in executive function was found (mean difference in z-score: -0.21, P = 0.02) without changes in other cognitive domains. Declines in rCMRglc were detected in the left superior temporal gyrus, right posterior cingulate gyrus, left parahippocampal gyrus, right lingual gyrus, and right angular gyrus. The change in executive function had a positive correlation with the percent change of rCMRglc in the right posterior cingulate gyrus (β = 0.43, P = 0.02).

CONCLUSIONS

Our findings suggest that elderly women with SMI symptoms should be carefully monitored for declines in executive function and related brain glucose metabolism over time.

Outcomes of stable and unstable patterns of subjective cognitive decline - results from the Leipzig Longitudinal Study of the Aged (LEILA75+)

Background

Subjective cognitive decline (SCD), i.e., the self-perceived feeling of worsening cognitive function, may be the first notable syndrome of preclinical Alzheimer’s disease and other dementias. However, not all individuals with SCD progress. Stability of SCD, i.e., repeated reports of SCD, could contribute to identify individuals at risk, as stable SCD may more likely reflect the continuous neurodegenerative process of Alzheimer’s and other dementias.

Methods

Cox regression analyses were used to assess the association between stability of SCD and progression to MCI and dementia in data derived from the population-based Leipzig Longitudinal Study of the Aged (LEILA75+).

Results

Of 453 cognitively unimpaired individuals with a mean age of 80.5 years (SD = 4.2), 139 (30.7 %) reported SCD at baseline. Over the study period (M = 4.8 years, SD = 2.2), 84 (18.5 %) individuals had stable SCD, 195 (43.1 %) unstable SCD and 174 (38.4 %) never reported SCD. Stable SCD was associated with increased risk of progression to MCI and dementia (unadjusted HR = 1.8, 95 % CI = 1.2–2.6; p < .01), whereas unstable SCD yielded a decreased progression risk (unadjusted HR = 0.5, 95 % CI = 0.4–0.7; p < .001) compared to no SCD. When adjusted for baseline cognitive functioning, progression risk in individuals with stable SCD was significantly increased in comparison to individuals with unstable SCD, but not compared to individuals without SCD.

Conclusions

Our results, though preliminary, suggest that stable SCD, i.e., repeated reports of SCD, may yield an increased risk of progression to MCI and dementia compared to unstable SCD. Baseline cognitive scores, though within a normal range, seem to be a driver of progression in stable SCD. Future research is warranted to investigate whether stability could hold as a SCD research feature.

Using Magnetoencephalography to Study Patterns of Brain Magnetic Activity in Alzheimer’s Disease

The use of magnetoencephalography to study neurophysiologic abnormalities associated with Alzheimer’s disease is reviewed. The most consistent observation is that Alzheimer’s disease patients exhibit an increase in focal slow-wave activity that covaried with cognitive performance. It is still unclear whether generation of focal slow-wave activity precedes or is a consequence of Alzheimer’s disease-related neuropathology. Also reviewed is the use of magnetoencephalography to identify early functional changes preceding the diagnosis of dementia. Magnetoencephalography detected neurophysiologic abnormalities associated with cognitive deficits before the diagnosis of mild cognitive impairment. This is supported by evidence presented suggesting that some patients with subjective cognitive complaints, without evidence of dementia, show an increase in focal slow-wave generators. Further research is needed to determine whether the outstanding spatial and temporal resolution of the magnetoencephalography technique could complement other neuroimaging techniques in identifying neurophysiologic abnormalities preceding the diagnosis of Alzheimer’s disease and mild cognitive impairment.

Incident Subjective Cognitive Decline Does Not Predict Mortality in the Elderly--Results from the Longitudinal German Study on Ageing, Cognition, and Dementia (AgeCoDe)

OBJECTIVE

Subjective cognitive decline (SCD) might represent the first symptomatic representation of Alzheimer's disease (AD), which is associated with increased mortality. Only few studies, however, have analyzed the association of SCD and mortality, and if so, based on prevalent cases. Thus, we investigated incident SCD in memory and mortality.

METHODS

Data were derived from the German AgeCoDe study, a prospective longitudinal study on the epidemiology of mild cognitive impairment (MCI) and dementia in primary care patients over 75 years covering an observation period of 7.5 years. We used univariate and multivariate Cox regression analyses to examine the relationship of SCD and mortality. Further, we estimated survival times by the Kaplan Meier method and case-fatality rates with regard to SCD.

RESULTS

Among 971 individuals without objective cognitive impairment, 233 (24.0%) incidentally expressed SCD at follow-up I. Incident SCD was not significantly associated with increased mortality in the univariate (HR = 1.0, 95% confidence interval = 0.8-1.3, p = .90) as well as in the multivariate analysis (HR = 0.9, 95% confidence interval = 0.7-1.2, p = .40). The same applied for SCD in relation to concerns. Mean survival time with SCD was 8.0 years (SD = 0.1) after onset.

CONCLUSION

Incident SCD in memory in individuals with unimpaired cognitive performance does not predict mortality. The main reason might be that SCD does not ultimately lead into future cognitive decline in any case. However, as prevalence studies suggest, subjectively perceived decline in non-memory cognitive domains might be associated with increased mortality. Future studies may address mortality in such other cognitive domains of SCD in incident cases.

Dementia risk estimates associated with measures of depression: a systematic review and meta-analysis

OBJECTIVES

To perform a systematic review of reported HRs of all cause dementia, Alzheimer's disease (AD) and vascular dementia (VaD) for late-life depression and depressive symptomatology on specific screening instruments at specific thresholds.

DESIGN

Meta-analysis with meta-regression.

SETTING AND PARTICIPANTS

PubMed, PsycInfo, and Cochrane databases were searched through 28 February 2014. Articles reporting HRs for incident all-cause dementia, AD and VaD based on published clinical criteria using validated measures of clinical depression or symptomatology from prospective studies of general population of adults were selected by consensus among multiple reviewers. Studies that did not use clinical dementia diagnoses or validated instruments for the assessment of depression were excluded. Data were extracted by two reviewers and reviewed by two other independent reviewers. The most specific analyses possible using continuous symptomatology ratings and categorical measures of clinical depression focusing on single instruments with defined reported cut-offs were conducted.

PRIMARY OUTCOME MEASURES

HRs for all-cause dementia, AD, and VaD were computed where possible for continuous depression scores, or for major depression assessed with single or comparable validated instruments.

RESULTS

Searches yielded 121,301 articles, of which 36 (0.03%) were eligible. Included studies provided a combined sample size of 66,532 individuals including 6593 cases of dementia, 2797 cases of AD and 585 cases of VaD. The increased risk associated with depression did not significantly differ by type of dementia and ranged from 83% to 104% for diagnostic thresholds consistent with major depression. Risk associated with continuous depression symptomatology measures were consistent with those for clinical thresholds.

CONCLUSIONS

Late-life depression is consistently and similarly associated with a twofold increased risk of dementia. The precise risk estimates produced in this study for specific instruments at specified thresholds will assist evidence-based medicine and inform policy on this important population health issue.

Development of a subjective cognitive decline questionnaire using item response theory: a pilot study

Introduction

Subjective cognitive decline (SCD) may indicate unhealthy cognitive changes, but no standardized SCD measurement exists. This pilot study aimed to identify reliable SCD questions.

Methods

A total of 112 cognitively normal (NC; 76 ± 8 years; 63% female), 43 mild cognitive impairment (MCI; 77 ± 7 years; 51% female), and 33 diagnostically ambiguous participants (79 ± 9 years; 58% female) were recruited from a research registry and completed 57 self-report SCD questions. Psychometric methods were used for item reduction.

Results

Factor analytic models assessed unidimensionality of the latent trait (SCD); 19 items were removed with extreme response distribution or trait-fit. Item response theory (IRT) provided information about question utility; 17 items with low information were dropped. Post hoc simulation using computerized adaptive test (CAT) modeling selected the most commonly used items (n = 9 of 21 items) that represented the latent trait well (r = 0.94) and differentiated NC from MCI participants (F [1, 146] = 8.9, P = .003).

Discussion

IRT and CAT modeling identified nine reliable SCD items. This pilot study is a first step toward refining SCD assessment in older adults. Replication of these findings and validation with Alzheimer's disease biomarkers will be an important next step for the creation of a SCD screener.

Do Subjective Memory Complaints Lead or Follow Objective Cognitive Change? A Five-Year Population Study of Temporal Influence

The relationship between subjective memory complaints (SM) and objective memory (OM) performance in aging has been variably characterized in a substantial literature, to date. In particular, cross-sectional studies often observe weak or no associations. We investigated whether subjective memory complaints and objectively measured cognition influence each other over time, and if so, which is the stronger pathway of change-objective to subjective, or subjective to objective-or whether they are both important. Using bivariate latent change score modeling in data from a population study (N=1980) over 5 annual assessment cycles, we tested four corresponding hypotheses: (1) no coupling between SM and OM over time; (2) SM as leading indicator of change in OM; (3) OM as leading indicator of change in SM; (4) dual coupling over time, with both SM and OM leading subsequent change in the other. We also extended objective cognition to two other domains, language and executive functions. The dual-coupling models best fit the data for all three objective cognitive domains. The SM-OM temporal dynamics differ qualitatively compared to other domains, potentially reflecting changes in insight and self-awareness specific to memory impairment. Subjective memory and objective cognition reciprocally influence each other over time. The temporal dynamics between subjective and objective cognition in aging are nuanced, and must be carefully disentangled to shed light on the underlying processes.

Subjective Cognitive Decline in Older Adults: An Overview of Self-Report Measures Used Across 19 International Research Studies

Research increasingly suggests that subjective cognitive decline (SCD) in older adults, in the absence of objective cognitive dysfunction or depression, may be a harbinger of non-normative cognitive decline and eventual progression to dementia. Little is known, however, about the key features of self-report measures currently used to assess SCD. The Subjective Cognitive Decline Initiative (SCD-I) Working Group is an international consortium established to develop a conceptual framework and research criteria for SCD (Jessen et al., 2014, Alzheimers Dement 10, 844-852). In the current study we systematically compared cognitive self-report items used by 19 SCD-I Working Group studies, representing 8 countries and 5 languages. We identified 34 self-report measures comprising 640 cognitive self-report items. There was little overlap among measures- approximately 75% of measures were used by only one study. Wide variation existed in response options and item content. Items pertaining to the memory domain predominated, accounting for about 60% of items surveyed, followed by executive function and attention, with 16% and 11% of the items, respectively. Items relating to memory for the names of people and the placement of common objects were represented on the greatest percentage of measures (56% each). Working group members reported that instrument selection decisions were often based on practical considerations beyond the study of SCD specifically, such as availability and brevity of measures. Results document the heterogeneity of approaches across studies to the emerging construct of SCD. We offer preliminary recommendations for instrument selection and future research directions including identifying items and measure formats associated with important clinical outcomes.

Risk of dementia and mild cognitive impairment in older people with subjective memory complaints: meta-analysis

OBJECTIVE

To investigate whether people with subjective memory complaints (SMC) but no objective deficits are at increased risk of developing mild cognitive impairment (MCI) and dementia.

METHOD

Major electronic databases were searched till 03/2014, and a meta-analysis was conducted using inception cohort studies.

RESULTS

Across 28 studies, there were 29,723 unique individuals (14,714 with SMC and 15,009 without SMC) (mean 71.6 years) followed on average for 4.8 years through to dementia. The annual conversion rate (ACR) of SMC to dementia was 2.33% (95% CI = 1.93%-2.78%) a relative risk (RR) of 2.07 (95% CI = 1.76-2.44) compared with those without SMC (n = 15,009). From 11 studies the ACR of developing MCI was 6.67% (95% CI = 4.70-8.95%). In long-term studies over 4 years, 14.1% (9.67-19.1%) of people with SMC developed dementia and 26.6% (95% CI = 5.3-39.7) went on to develop MCI. The ACR from SMC to dementia and MCI were comparable in community and non-community settings.

CONCLUSION

Older people with SMC but no objective complaints are twice as likely to develop dementia as individuals without SMC. Approximately 2.3% and 6.6% of older people with SMC will progress to dementia and MCI per year.

Demographic, clinical, and lifestyle correlates of subjective memory complaints in the Australian population

OBJECTIVES

To provide estimates of the prevalence and correlates of subjective memory complaints in older individuals by using population-based Australian data.

DESIGN

2007 National Survey of Mental Health and Well-Being.

SETTING

Australia.

PARTICIPANTS

1,905 community-dwelling participants aged 65-85 years.

MEASUREMENTS

Subjective memory complaints were assessed by using two questions reflecting: (1) poorer memory compared with others of the same age ("worse memory"); and (2) a decline in memory performance over the previous 5 years ("declining memory"). Twelve-month and lifetime diagnoses were derived from structured diagnostic interviews. Other correlates investigated included chronic physical conditions, lifestyle factors, and service use. Analyses adjusted for scores on the Mini-Mental State Examination.

RESULTS

Subjective memory complaints were reported by one-third (33.5%) of respondents. Those who reported either complaint were more likely to report psychological distress, poor functioning, service use, and negative self-assessed mental and physical health. "Declining memory" over the past 5 years was also related to an increase in the rates of psychiatric disorders. After adjusting for other variables of interest, associations were established between subjective memory complaints and psychological distress, poor functioning, negative self-assessed mental health, and alcohol use disorders. Except for the association between "declining memory" and anxiety and depression, these associations remained significant after excluding those with scores <27 on the Mini-Mental State Examination.

CONCLUSIONS

Subjective memory complaints were associated with several negative clinical characteristics that should be considered when interpreting these complaints. Subjective memory complaints may be valid indicators of psychopathology and the need for clinical assessment.

Coenzyme Q10 benefits symptoms in Gulf War veterans: results of a randomized double-blind study

We sought to assess whether coenzyme Q10 (CoQ10) benefits the chronic multisymptom problems that affect one-quarter to one-third of 1990-1 Gulf War veterans, using a randomized, double-blind, placebo-controlled study. Participants were 46 veterans meeting Kansas and Centers for Disease Control criteria for Gulf War illness. Intervention was PharmaNord (Denmark) CoQ10 100 mg per day (Q100), 300 mg per day (Q300), or an identical-appearing placebo for 3.5 ± 0.5 months. General self-rated health (GSRH), the primary outcome, differed across randomization arms at baseline, and sex significantly predicted GSRH change, compelling adjustment for baseline GSRH and prompting sex-stratified analysis. GSRH showed no significant benefit in the combined-sex sample. Among males (85% of participants), Q100 significantly benefited GSRH versus placebo and versus Q300, providing emphasis on Q100. Physical function (summary performance score, SPS) improved on Q100 versus placebo. A rise in CoQ10 approached significance as a predictor of improvement in GSRH and significantly predicted SPS improvement. Among 20 symptoms each present in half or more of the enrolled veterans, direction-of-difference on Q100 versus placebo was favorable for all except sleep problems; sign test 19:1, p=0.00004) with several symptoms individually significant. Significance for these symptoms despite the small sample underscores large effect sizes, and an apparent relation of key outcomes to CoQ10 change increases prospects for causality. In conclusion, Q100 conferred benefit to physical function and symptoms in veterans with Gulf War illness. Examination in a larger sample is warranted, and findings from this study can inform the conduct of a larger trial.

A short tool to screen HIV-infected patients for mild neurocognitive disorders - a pilot study

Background

We aimed to evaluate the accuracy and acceptability of a short screening test battery for mild neurocognitive deficits.

Methods

HIV-infected individuals with a suppressed viral load were examined at the University Hospital Basel with a screening test consisting of a questionnaire and selected cognitive tests, administered by trained nurses, followed by an in-depth neuropsychological examination. Test acceptance was evaluated with a questionnaire.

Results

30 patients were included in this study (median age of 52.5 years (interquartile range (IQR) 47–64), prior AIDS-defining condition in 37%, median CD4 cell count 658 (IQR 497–814) cells/μl). Overall, 25 (83%) patients were diagnosed with HIV-associated neurocognitive disorders (HAND) on in-depth neuropsychological assessment (16 patients had asymptomatic neurocognitive impairment (ANI), 8 a mild neurocognitive disorder (MND) and 1 patient HIV-associated dementia (HAD). Among 25 patients with HAND, only 9 patients (36%) were complaining of memory loss. The screening battery revealed neurocognitive deficits in 17 (57%) patients (sensitivity 64%, specificity 80%, positive predictive value 94% and negative predictive value 31%). Most patients (83%) estimated the screening test as valuable and not worrisome.

Conclusions

A questionnaire combined with selected neuropsychological tests is a short, easy-to-perform very well accepted screening tool for mild neurocognitive disorders in asymptomatic HIV-infected individuals.

The unbearable lightness of MCI

The title of this Editorial, with apologies to Milan Kundera (Kundera, 1985) implies no lack of gravitas in the concept of Mild Cognitive Impairment (MCI). Rather, it refers to the current definitions of MCI being somewhat free-floating, loosely anchored to diagnostic frameworks, and more conceptual than operational. In their defense, we cannot completely obliterate the flexibility clinicians need in order to exercise expert judgment and take individual patients’ circumstances into account when making clinical diagnoses. Further, it would be imprudent to prematurely codify diagnostic criteria for MCI; after all, we are still gathering basic information about the wide range of mildly impaired states that we encounter in different clinical settings and in the population at large.

Subjective cognitive complaints and mortality: does the type of complaint matter?

Middle-aged subjects report subjective cognitive complaints (SSCs) but whether these are meaningfully related to health remains unknown. We examined the association between SCCs, both amnestic and non-amnestic, and mortality in a middle-aged population after taking into account the role of depression. 15,510 participants (26.2% women), mean age 57.9 years in 2002, from the French GAZEL study provided data on 3 measures of SCCs: memory complaints, cognitive symptoms (forgetfulness, difficulties in recalling memories, retaining new information, mental calculation, in language, and orientation) and whether they sought medical advice for SCCs. All-cause mortality was assessed between 2002 and 2012. Over the follow-up 56.3% participants reported memory problems, 62.6% cognitive complaints, 22.3% sought medical advice and 651 died. All SCCs were strongly associated (odds ratio 2.08-6.35) with depression which was itself associated with greater mortality (HR = 1.77, 95% CI: 1.50, 2.09). In analyses adjusted for age, sex, education, marital status and depression difficulty in mental calculation (HR = 1.30, 95% CI: 1.08, 1.60) and seeking medical advice for cognitive symptoms (HR = 1.41, 95% CI: 1.18, 1.68) were significantly associated with mortality, while memory complaints did not carry increased risk (HR = 0.93, 95% CI: 0.79, 1.09). All SCCS were strongly associated with depression but not all carried excess risk of mortality.

Cognitive decline predicts long-term care insurance requirement certification in community-dwelling older Japanese adults: a prospective cohort study

AIM

The purpose of this prospective cohort study is to examine whether cognitive decline is an independent predictor of new long-term care insurance (LTCI) requirement certifications in Japan.

METHODS

A total of 5,765 community-dwelling older Japanese adults who, at baseline, were independent in terms of their activities of daily living participated in this study and were followed up for 18 months. The outcome measure was the number of new LTCI requirement certifications during the 18-month period of the study. We collected demographic information through questionnaires and assessed cognitive skills with the Cognitive Performance Scale (CPS). The participants were divided into 3 groups according to CPS scores (0, 1, and 2 or greater).

RESULTS

During the 18-month period, 399 subjects (6.9%) became newly certified for LTCI services. In a multivariate Cox proportional hazards model, older participants with a CPS score of 1 (adjusted HR: 1.39, 95% CI: 1.08-1.77) and 2 or greater (adjusted HR: 2.27, 95% CI: 1.74-2.96) were significantly more likely to receive an LTCI certification compared to those with a CPS score of 0.

CONCLUSIONS

Cognitive decline is an independent predictor of new LTCI requirement certifications and the severity of cognitive decline in elderly adults is positively associated with receiving an LTCI requirement certification in Japan.

Mortality and morbidity hazards associated with cognitive status in seniors: a Canadian population prospective cohort study

INTRODUCTION

Although cognitive impairment is widely accepted as a leading indicator of dementia, influences of cognitive status on incident dementia and mortality remain unclear. The present study investigated the morbidity hazard associated with cognitive impairment and the mortality hazard associated with dementia in comparison to cognitively intact seniors.

METHODS

A population-based sample of 2914 seniors with clinically diagnosed cognitive status at Wave I (1991-1992) of the Canadian Study of Health and Aging (CSHA) were followed-up 5 years later (1996-1997). At Wave I, there were 921 cognitively intact, 861 cognitively impaired but not demented (CIND), and 1132 seniors with dementia, respectively. The primary outcome measures 5 years later were being cognitively intact, CIND, dementia and death. Kaplan-Meier estimates, log-rank tests, and Cox's proportional models were used in the analyses.

RESULTS

Respondents with CIND at Wave I were 2.191 times (95%CI 1.706-2.814) more likely to have dementia 5 years later than cognitively intact seniors. After adjusting for confounding socio-demographic and health status factors, the odds ratio was reduced to 2.147 times (95%CI 1.662-2.774), but remained significant. Respondents with CIND had a mortality rate 1.869 times (95%CI 1.602-2.179) and seniors with dementia 3.362 times greater (95%CI 2.929-3.860) than that of seniors who were cognitively intact. After controlling the confounders, the odds remained significant at 1.576 (95%CI 1.348-1.843) for CIND respondents and 2.415 (95%CI 2.083-2.800) for seniors with dementia.

DISCUSSION

CIND increases both the risk of dementia and mortality. Early intervention with CIND is warranted to reduce both dementia incidence and mortality.

Does self-rated health predict dementia?

OBJECTIVES

1. To determine if Self-Rated Health (SRH) predicts dementia over a five period in cognitively intact older adults, and in older adults with Cognitive Impairment, No Dementia (CIND); and 2. To determine if different methods of eliciting SRH (age-referenced (AR) versus unreferenced) yield similar results.

DESIGN

Prospective cohort.

POPULATION

1468 cognitively intact adults and 94 older adults with CIND aged 65+ living in the community, followed over five years.

MEASURES

Age, gender, education, subjective memory loss, depressive symptoms, functional status, cognition, SRH and AR-SRH were all measured; dementia was diagnosed on clinical examination. Those with abnormal cognition not meeting criteria for dementia were diagnosed with CIND.

RESULTS

In those who were cognitively intact at time 1, and had good SRH: 69.4% were intact; 6.0% had CIND; 6.9% had dementia, and 17.7% had died at time 2, while in those with poor SRH: 44.9% were intact, 11.1% had CIND, 9.1% had dementia, and 34.8% had died (p<0.001, chi-square test). In multinomial regression models SRH predicted dementia and death. In those with CIND at time 1 and good SRH: 2.3% were intact: 18.6% had CIND; 34.9% had dementia and 44.2% had died at time 2, while in those with poor SRH: 4.8% were intact, 31.0% had CIND, 19.0% had dementia, and 43.6% had died (p=0.30, chi-square test). In multinomial regression models, this was not significant. AR-SRH analyses were similar.

CONCLUSIONS

In cognitively intact older adults SRH predicts dementia. In older adults with CIND, SRH does not predict dementia.

Online memory screening--are older adults interested and can it work?

Subjective memory concerns are common in older adults and may prompt the use of web-based cognitive screening. Websites which purport to provide memory screening are numerous and can influence health behaviours; however there is currently limited evidence regarding their validity. The current research aims to assess potential user's attitudes and motivations regarding online cognitive screening and to evaluate the preliminary evidence for the feasibility and validity of two subjective online cognitive measures. The sample consisted of community-based older adults, 30 with, and 30 without, memory concerns. Participants rated their likelihood of their accessing online cognitive screening and gave rationales. Participants' performance on objective pen and paper measures of cognition was compared to performance on subjective online screening measures. The majority of participants indicated they would access online cognitive screening. A total of 100% of participants were able to use the online tools without assistance. None of the online measures was positively associated with the pen and paper screening measures. Anxiety and depression were significantly associated with subjective memory concerns. This study provided no supporting evidence for the validity of either subjective online screening measure assessed. Anxiety and depression were significantly associated with subjective cognition, indicating that, although they may not predict objective cognition, complaints about memory in older adults should be taken seriously by health professionals.