Prevalence of mild cognitive impairment: a population-based study in elderly subjects

Cross-cultural Diagnostic Validity of the Multilingual Naming Test (MINT) in a Sample of Older Adults

OBJECTIVE

We aimed to evaluate the psychometric properties and diagnostic accuracy of the 32-item version of the Multilingual Naming Test (MINT) in participants from 2 ethnic groups (European Americans [EA; n = 106] and Hispanic Americans [HA; n = 175]) with 3 diagnostic groups (cognitively normal [CN], n = 94, mild cognitive impairment [MCI], n = 148, and dementia, n = 39).

METHOD

An Item Response Theory model was used to evaluate items across ethnicity and language groups (Spanish and English), resulting in a 24-item version. We analyzed the MINT discriminant and predictive validity across diagnostic groups.

RESULTS

A total of 8 items were differentially difficult between languages in the 32-item version of the MINT. EA scored significantly higher than HA, but the difference was not significant when removing those 8 items (controlling for Education). The Receiver Operating Characteristics showed that the MINT had poor accuracy when identifying CN participants and was acceptable in identifying dementia participants but unacceptable in classifying MCI participants. Finally, we tested the association between MINT scores and magnetic resonance imaging volumetric measures of language-related areas in the temporal and frontal lobes. The 32-item MINT in English and Spanish and the 24-item MINT in Spanish were significantly correlated with the bilateral middle temporal gyrus. The left fusiform gyrus correlated with MINT scores regardless of language and MINT version. We also found differential correlations depending on the language of administration.

CONCLUSIONS

Our results highlight the importance of analyzing cross-cultural samples when implementing clinical neuropsychological tests such as the MINT.

A household survey of the prevalence of subjective cognitive decline and mild cognitive impairment among urban community-dwelling adults aged 30 to 65

While it is possible to detect cognitive decline before the age of 60, and there is a report indicating that certain cognitive abilities peak in one's 30s, the evidence regarding cognitive problems in populations younger than 65 years is scarce. This study aims to (1) determine the proportion of community-dwelling adults with different cognitive status, and (2) determine the prevalence of neuropsychiatric behaviors. A population-based survey was conducted in Chiang Mai, Thailand. Individuals aged 30 to 65 were recruited and assessed for demographic data, memory complaints, cognitive performance, and neuropsychiatric symptoms using self-reported questionnaires. In a total of 539 participants, 33.95% had mild cognitive impairment (MCI), 7.05% had subjective cognitive decline (SCD), and 52.50% had neuropsychiatric symptoms. The risk of MCI increased with age, and neuropsychiatric symptoms were significantly higher in those with MCI or SCD than in those without (p < 0.001). The most common complaints were sleep problems, anxiety, and irritability. Screening for MCI in adults aged < 65 years might be useful. However, further investigation on the appropriate age to screen and the program's cost-effectiveness is suggested.

Pattern of cognitive impairment among community-dwelling elderly in Egypt and its relation to socioeconomic status

BACKGROUND

Cognitive decline is one of the aging health problems that strongly affects daily functioning and quality of life of older adults and threatens their independence. The aim of this study was to assess the prevalence and pattern of cognitive impairment (CI) among community-dwelling elderly in Egypt and the contribution of socioeconomic status to inequality in cognitive impairment.

METHODS

A cross-sectional study involved 470 community-dwelling elderly aged 60 years or older living in Kafr El-Sheikh Governorate, Egypt. Subjects were recruited from home visits, geriatric clubs, and outpatient clinics. The Montreal Cognitive Assessment tools (MoCA & MoCA-B) were used to assess the prevalence of cognitive impairment, Hachinski ischemic score (HIS) to investigate the type of cognitive impairment, Ain Shams Cognitive Assessment (ASCA) tool to assess the pattern of specific cognitive domain affection, and an Egyptian socioeconomic status (SES) scale to classify the SES of the study participants.

RESULTS

The prevalence of cognitive impairment was 50.2% distributed as 37.7% for mild cognitive impairment (MCI) and 12.5% for dementia. The most common type of cognitive impairment was the degenerative type (47.9%). Pattern of specific domain affection among cognitively impaired subjects ranged from 94% for visuospatial function to 12.7% for abstraction. Cognitive impairment was significantly higher with increasing age, female sex, marital status (single or widow), low education, higher number of comorbidities, and positive family history of cognitive impairment (p < 0.001). Also, cognitive impairment was concentrated mainly among participants with low socioeconomic score (p < 0.001).

CONCLUSION

In Egypt, cognitive impairment is significantly prevalent and concentrated among those who are in low socioeconomic status. Patients with mild CI were more than those with dementia, and the most common type of CI was the degenerative type. Increasing educational level of low SES population and improving their access to healthcare services are highly recommended to improve the inequity of cognitive impairment.

Association between the neutrophil-to-lymphocyte ratio and cognitive impairment: a meta-analysis of observational studies

Background

Systemic inflammation is one of the underlying mechanisms of cognitive impairment. The neutrophil-to-lymphocyte ratio (NLR) has emerged as a systemic inflammation indicator. This meta-analysis aimed to evaluate the association between high NLR and cognitive impairment (CI) risk.

Method

A comprehensive systematic search was conducted to identify eligible studies published until May 30, 2023. The reference group comprised patients with the lowest NLR level, whereas the exposure group comprised those with the highest NLR level. The main outcome was to examine the relationship between NLR and CI risk. The secondary outcome included the association between patient characteristics or comorbidities and CI risk.

Results

This meta-analysis included 11 studies published between 2018 and 2023, involving 10,357 patients. Patients with CI had a higher NLR than those without (mean difference=0.35, 95% confidence interval [CI]: 0.26-0.44, p < 00001, I2 = 86%). Consistently, pooled results revealed an association between high NLR and CI risk (odds ratio [OR]=2.53, 95% CI:1.67-3.82, p<0.0001, I2 = 84%). Furthermore, aging (mean difference =4.31 years, 95% CI:2.83-5.8, p < 0.00001, I2 = 92%), diabetes (OR=1.59, 95% CI:1.35-1.88, p < 0.00001, I2 = 66%), and hypertension (OR=1.36, 95% CI:1.19-1.57, p < 0.00001, I2 = 0%) were significant risk factors for CI. However, no significant associations were observed between CI and male gender (OR = 0.84, 95% CI:0.64-1.11, p = 0.22, I2 = 81%), body mass index (mean = -0.32 kg/m2, 95% CI: -0.82, 0.18, p = 0.2, I2 = 82%), alcohol consumption (OR = 1.11, 95% CI:0.95-1.3, p = 1.35, I2 = 0%), and smoking (OR = 0.99, 95% CI:0.87-1.13, p = 0.86, I2 = 0%). Meta-regression found that diabetes and hypertension, but not age, significantly moderated the association between NLR and CI.

Conclusion

This meta-analysis showed a significant association between high NLR and increased CI risk. Moreover, meta-regression identified diabetes and hypertension, but not age, as significant moderating factors in the relationship between NLR and CI. To validate and strengthen these findings, further large-scale studies are required.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023430384, identifier CRD42023430384.

Cognitive impairment indicator for the neuropsychological test batteries in the Canadian Longitudinal Study on Aging: definition and evidence for validity

BACKGROUND

Prevalence of overall cognitive impairment based on each participant's performance across a neuropsychological battery is challenging; consequently, we define and validate a dichotomous cognitive impairment/no cognitive indicator (CII) using a neuropsychological battery administered in a population-based study. This CII approximates the clinical practice of interpretation across a neuropsychological battery and can be applied to any neuropsychological dataset.

METHODS

Using data from participants aged 45-85 in the Canadian Longitudinal Study on Aging receiving a telephone-administered neuropsychological battery (Tracking, N = 21,241) or a longer in-person battery (Comprehensive, N = 30,097), impairment was determined for each neuropsychological test based on comparison with normative data. We adjusted for the joint probability of abnormally low scores on multiple neuropsychological tests using baserates of low scores demonstrated in the normative samples and created a dichotomous CII (i.e., cognitive impairment vs no cognitive impairment). Convergent and discriminant validity of the CII were assessed with logistic regression analyses.

RESULTS

Using the CII, the prevalence of cognitive impairment was 4.3% in the Tracking and 5.0% in the Comprehensive cohorts. The CII demonstrated strong convergent and discriminant validity.

CONCLUSIONS

The approach for the CII is a feasible method to identify participants who demonstrate cognitive impairment on a battery of tests. These methods can be applied in other epidemiological studies that use neuropsychological batteries.

Exploring the Impact of Age of Onset of Mild Cognitive Impairment on the Profile of Cognitive and Psychiatric Symptoms

The present study aims to explore the differences in the manifestation of cognitive decline and psychiatric symptoms across the different ages of MCI onset: early onset (EOMCI: <65 years old), middle onset (MOMCI: 65-75 years old), and late onset (LOMCI: >75 years old). It was hypothesized that individuals with EOMCI will preserve their cognitive functions to a greater extent as compared to individuals with LOMCI, even after adjusting the cognitive performance for age and education through the use of published Greek norms. The level of cognitive decline concerning MOMCI was evaluated for extracting more precise conclusions regarding the impact of the age of onset on the patterns of MCI symptomatology. The analyses of data were conducted in a Greek population of individuals with MCI, who were consecutive visitors of the Outpatient Memory Clinic of Nestor Alzheimer's Centre in Athens, Greece. The sample consisted of 297 participants who fulfilled the following inclusion criteria: MCI diagnosis based on Petersen's criteria, Greek mother language, and absence of a psychiatric history or chronic and incurable organic disease. The overall results support the presence of a cognitive advantage of the EOMCI group compared to the LOMCI group. In the MOMCI group, cognitive performance displayed a tendency to remain intermediate compared to the other two groups. Nonetheless, significant differences were observed when this group was compared with the LOMCI group. The current findings indicate that the age of onset should be taken under consideration in the neuropsychological assessment of individuals with MCI. The specific parameters could have implications in terms of prognosis as well as the design and implementation of tailored interventions.

The association between shift work exposure and cognitive impairment among middle-aged and older adults: Results from the Canadian Longitudinal Study on Aging (CLSA)

BACKGROUND

Shift work, especially rotating and night shift work, has been linked to a wide range of detrimental health outcomes. Occupational factors like shift work and their potential impact on cognitive functions have received little attention, and the evidence is inconclusive. The objective of our study is to explore associations between shift work exposure and cognitive impairment indicators based on comparisons with the normative standards from the Canadian population.

METHODS

Cross-sectional analyses were performed using baseline Canadian Longitudinal Study on Aging database, including 47,811 middle-aged and older adults (45-85 years). Three derived shift work variables were utilized: ever exposed to shift work, shift work exposure in longest job, and shift work exposure in current job. Four cognitive function tests were utilized, Rey Auditory Verbal Learning Tests (immediate and delayed) representing memory domain, and Animal Fluency, and Mental Alteration, representing the executive function domain. All cognitive test scores included in study were normalized and adjusted for the participant's age, sex, education and language of test administration (English and French), which were then compared to normative data to create "cognitive impairment' variables. Unadjusted and adjusted multivariable logistic regression models were used to determine associations between shift work variables and cognitive impairment individually (memory and executive function domains), and also for overall cognitive impairment.

RESULT

Overall, one in every five individuals (21%) reported having been exposed to some kind of shift work during their jobs. Exposure to night shift work (both current and longest job) was associated with overall cognitive impairment. In terms of domain-based measures, night shift work (longest job) was associated with memory function impairment, and those exposed to rotating shift work (both current and longest job) showed impairment on executive function measures, when compared to daytime workers.

CONCLUSION

This study suggests disruption to the circadian rhythm, due to shift work has negative impact on cognitive function in middle-aged and older adults and this warrants further investigation.

Review articles (Meta-Analyses) effects of walking on cognitive function in individuals with mild cognitive impairment: a systematic review and meta-analysis

BACKGROUND

Mild cognitive impairment (MCI) is the stage between the expected cognitive decline of normal aging and the more serious decline of dementia. Previous studies have shown that regular exercise can improve cognition and physical performance in older adults. Walking is a low-technology and low-cost exercise that has been proven to improve cognition and mobility in healthy elderly individuals. However, no systematic review or meta-analysis has explored whether walking can improve cognitive function in older adults with MCI. This study aimed to explore the effects of walking interventions on cognitive functions in individuals with MCI.

METHODS

In accordance with the PRISMA guidelines, MEDLINE, PubMed, SPORTDiscus, Cochrane Central Register of Controlled Trials, CINAHL, Web of Science, Airiti Library, and the National Digital Library of Theses and Dissertations in Taiwan were searched from inception to July 2023. Independent reviewers selected randomized clinical trials (RCT) that compared the effects of walking with no intervention or other exercises in individuals with MCI. The primary outcomes were cognitive functions, and the secondary outcome was walking endurance. Three reviewers independently conducted data extraction. The risk of bias was assessed using the Revised Cochrane Risk of Bias assessment tool.

RESULTS

Fourteen RCTs were included in this review. The quality of evidence in these studies was rated as good to excellent. The results of the meta-analysis showed that the individuals with MCI had no significant improvement in cognitive function but had significant improvement in the 6-min walk test (Mean Difference=23.70, p=0.008) after walking interventions compared to no intervention or other exercises.

CONCLUSION

Walking intervention has no significant improvement on cognitive functions in older adults with MCI. However, walking induces beneficial effects on aerobic capacity.

TRIAL REGISTRATION

This systematic review has the registration number CRD42021283753 on PROSPERO.

Stability in cognitive classification as a function of severity of impairment and ethnicity: A longitudinal analysis

OBJECTIVE

The interaction of ethnicity, progression of cognitive impairment, and neuroimaging biomarkers of Alzheimer's Disease remains unclear. We investigated the stability in cognitive status classification (cognitively normal [CN] and mild cognitive impairment [MCI]) of 209 participants (124 Hispanics/Latinos and 85 European Americans).

METHODS

Biomarkers (structural MRI and amyloid PET scans) were compared between Hispanic/Latino and European American individuals who presented a change in cognitive diagnosis during the second or third follow-up and those who remained stable over time.

RESULTS

There were no significant differences in biomarkers between ethnic groups in any of the diagnostic categories. The frequency of CN and MCI participants who were progressors (progressed to a more severe cognitive diagnosis at follow-up) and non-progressors (either stable through follow-ups or unstable [progressed but later reverted to a diagnosis of CN]) did not significantly differ across ethnic groups. Progressors had greater atrophy in the hippocampus (HP) and entorhinal cortex (ERC) at baseline compared to unstable non-progressors (reverters) for both ethnic groups, and more significant ERC atrophy was observed among progressors of the Hispanic/Latino group. For European Americans diagnosed with MCI, there were 60% more progressors than reverters (reverted from MCI to CN), while among Hispanics/Latinos with MCI, there were 7% more reverters than progressors. Binomial logistic regressions predicting progression, including brain biomarkers, MMSE, and ethnicity, demonstrated that only MMSE was a predictor for CN participants at baseline. However, for MCI participants at baseline, HP atrophy, ERC atrophy, and MMSE predicted progression.

Aggressive behavior and prognosis in patients with mild cognitive impairment

The diagnosis of mild cognitive impairment (MCI) is associated with an increased risk of developing dementia. When evaluating the further prognosis of MCI, the occurrence of neuropsychiatric symptoms, particularly aggressive and impulsive behavior, may play an important role.

Objective

The aim of this study was to evaluate the relationship between aggressive behavior and cognitive dysfunction in patients diagnosed with MCI.

Methods

The results are based on a 7-year prospective study. At the time of inclusion in the study, participants, recruited from an outpatient clinic, were assessed with Mini-Mental State Examination (MMSE) and the Cohen-Mansfield Agitation Inventory (CMAI). A reassessment was performed after 1 year using the MMSE scale in all patients. The time of next MMSE administration was depended on the clinical condition of patients took place at the end of follow-up, that is, at the time of diagnosis of the dementia or after 7 years from inclusion when the criteria for dementia were not met.

Results

Of the 193 patients enrolled in the study, 75 were included in the final analysis. Patients who converted to dementia during the observation period exhibited a greater severity of symptoms in each of the assessed CMAI categories. Moreover, there was a significant correlation between the global result of CMAI and the results of the physical nonaggressive and verbal aggressive subscales with cognitive decline during the first year of observation.

Conclusions

Despite several limitations to the study, aggressive and impulsive behaviors seem to be an unfavorable prognostic factor in the course of MCI.

Orthogonal latent space learning with feature weighting and graph learning for multimodal Alzheimer's disease diagnosis

Recent studies have shown that multimodal neuroimaging data provide complementary information of the brain and latent space-based methods have achieved promising results in fusing multimodal data for Alzheimer's disease (AD) diagnosis. However, most existing methods treat all features equally and adopt nonorthogonal projections to learn the latent space, which cannot retain enough discriminative information in the latent space. Besides, they usually preserve the relationships among subjects in the latent space based on the similarity graph constructed on original features for performance boosting. However, the noises and redundant features significantly corrupt the graph. To address these limitations, we propose an Orthogonal Latent space learning with Feature weighting and Graph learning (OLFG) model for multimodal AD diagnosis. Specifically, we map multiple modalities into a common latent space by orthogonal constrained projection to capture the discriminative information for AD diagnosis. Then, a feature weighting matrix is utilized to sort the importance of features in AD diagnosis adaptively. Besides, we devise a regularization term with learned graph to preserve the local structure of the data in the latent space and integrate the graph construction into the learning processing for accurately encoding the relationships among samples. Instead of constructing a similarity graph for each modality, we learn a joint graph for multiple modalities to capture the correlations among modalities. Finally, the representations in the latent space are projected into the target space to perform AD diagnosis. An alternating optimization algorithm with proved convergence is developed to solve the optimization objective. Extensive experimental results show the effectiveness of the proposed method.

The Effects of a New Integrated and Multidisciplinary Cognitive Rehabilitation Program Based on Mindfulness and Reminiscence Therapy in Patients with Parkinson's Disease and Mild Cognitive Impairment: A Pilot Study

Background: Mindfulness trainings have shown promising results as treatment for behavioural symptoms in several pathologies. In addition, mindfulness protocols induced an improvement in memory and attention. Therefore, mindfulness could be an effective intervention for patients affected by Parkinson's disease (PD) and mild cognitive impairment (MCI), who are characterized by both behavioural and cognitive dysfunctions. Methods: We assessed differences in Montreal Cognitive Assessment (MoCA) scores and in Beck Depression Inventory II (BDI-II) scores in patients affected by PD and MCI enrolled in two different rehabilitation programs (an experimental vs. an usual structured program for cognitive rehabilitation). Participants in the experimental group (MILC-tr) underwent innovative rehabilitation program involving mindfulness and reminiscence activities. Assessments were performed before (T0) and at the end of the rehabilitation program (T1). Results: Friedman test showed a significant improvement between timepoints in MoCA global score (x² = 4.000, p = 0.046), MoCA memory sub-scale score (x² = 4.571, p = 0.033), and BDI-II cognitive and affective factors (x² = 4.000, p = 0.046) only for patients in MILC-tr group. Mann-Whitney test showed a significant difference between group comparing differences in Δ scores between T0 and T1 in the MoCA memory sub-scale score (U = 190.50, p = 0.035). Conclusions: Mindfulness-based rehabilitation programs could be effective in patients affected by PD and MCI.

Reduced Peripheral Nerve Conduction Velocity is Associated with Alzheimer's Disease: A Cross-Sectional Study from China

PURPOSE

Elderly individuals with degenerative diseases of the central nervous system are more likely to develop peripheral neuropathy; however, research is limited as to whether the decline in peripheral nerve conduction can be used as a biomarker of Alzheimer's disease (AD).

PATIENTS AND METHODS

This study enrolled 74 patients with mild cognitive impairment (MCI), 21 with AD, and 82 healthy elderly individuals. All participants underwent a peripheral nerve conduction and neuropsychological evaluation. Nicolet EDX was used to assess peripheral nerve conduction in the limbs and comparisons were made between the three cognitive groups. Furthermore, the relationship between peripheral nerve conduction and cognitive function was investigated.

RESULTS

A ladder-shaped difference was found in the median (p < 0.001) and common peroneal (p < 0.001) motor nerve velocity, with the control group > MCI group > AD group, even after controlling for variables. The median motor nerve amplitude in the AD group was lower than that in the control group (P = 0.017). After controlling for age, sex, education, and height, the median motor nerve velocity was positively correlated with the Montreal Cognitive Assessment (r = 0.196, p = 0.015), and the common peroneal motor nerve velocity was positively correlated with verbal fluency task-idioms (r = 0.184, p = 0.026). The median (AUC: 0.777, p < 0.001) and common peroneal motor nerve velocities (AUC: 0.862; p < 0.001) were significantly associated with the diagnosis of AD. The accuracy rate of these two motor nerve velocities to predict AD was 51.5%.

CONCLUSION

Our study found that peripheral motor nerve velocity may correlate with early cognitive impairment in AD. However, the accuracy of different cognitive classifications and the value of early diagnosis are not ideal when peripheral motor nerve velocity is used alone. Whether peripheral nerve function can be used as a marker for early diagnosis of AD needs further clarification but provides a new possibility for the future of biomarker research.

The complex burden of determining prevalence rates of mild cognitive impairment: A systematic review

Mild cognitive impairment (MCI) is a syndrome characterized by a decline in cognitive performance greater than expected for an individual's age and education level, but that does not interfere much with daily life activities. Establishing the prevalence of MCI is very important for both clinical and research fields. In fact, in a certain percentage of cases, MCI represents a prodromal condition for the development of dementia. Accordingly, it is important to identify the characteristics of MCI that allow us to predict the development of dementia. Also, initial detection of cognitive decline can allow the early implementation of prevention programs aimed at counteracting or slowing it down. To this end, it is important to have a clear picture of the prevalence of MCI and, consequently, of the diagnostic criteria used. According to these issues, this systematic review aims to analyze MCI prevalence, exploring the methods for diagnosing MCI that determine its prevalence. The review process was conducted according to the PRISMA statement. Three thousand one hundred twenty-one international articles were screened, and sixty-six were retained. In these studies, which involved 157,035 subjects, the prevalence of MCI ranged from 1.2 to 87%. The review results showed a large heterogeneity among studies due to differences in the subjects' recruitment, the diagnostic criteria, the assessed cognitive domains, and other methodological aspects that account for a higher range of MCI prevalence. This large heterogeneity prevents drawing any firm conclusion about the prevalence of MCI.

Neuroimaging Biomarkers Predicting the Efficacy of Multimodal Rehabilitative Intervention in the Alzheimer's Dementia Continuum Pathology

In this work we aimed to identify neural predictors of the efficacy of multimodal rehabilitative interventions in AD-continuum patients in the attempt to identify ideal candidates to improve the treatment outcome. Subjects in the AD continuum who participated in a multimodal rehabilitative treatment were included in the analysis [n = 82, 38 Males, mean age = 76 ± 5.30, mean education years = 9.09 ± 3.81, Mini Mental State Examination (MMSE) mean score = 23.31 ± 3.81]. All subjects underwent an MRI acquisition (1.5T) at baseline (T0) and a neuropsychological evaluation before (T0) and after intervention (T1). All subjects underwent an intensive multimodal cognitive rehabilitation (8–10 weeks). The MMSE and Neuropsychiatric Inventory (NPI) scores were considered as the main cognitive and behavioral outcome measures, and Delta change scores (T1–T0) were categorized in Improved (ΔMMSE > 0; ΔNPI < 0) and Not Improved (ΔMMSE ≤ 0; ΔNPI ≥ 0). Logistic Regression (LR) and Random Forest classification models were performed including neural markers (Medial Temporal Brain; Posterior Brain (PB); Frontal Brain (FB), Subcortical Brain indexes), neuropsychological (MMSE, NPI, verbal fluencies), and demographical variables (sex, age, education) at baseline. More than 50% of patients showed a positive effect of the treatment (ΔMMSE > 0: 51%, ΔNPI < 0: 52%). LR model on ΔMMSE (Improved vs. Not Improved) indicate a predictive role for MMSE score (p = 0.003) and PB index (p = 0.005), especially the right PB (p = 0.002) at baseline. The Random Forest analysis correctly classified 77% of cognitively improved and not improved AD patients. Concerning the NPI, LR model on ΔNPI (Improved vs. Not Improved) showed a predictive role of sex (p = 0.002), NPI (p = 0.005), PB index (p = 0.006), and FB index (p = 0.039) at baseline. The Random Forest reported a classification accuracy of 86%. Our data indicate that cognitive and behavioral status alone are not sufficient to identify best responders to a multidomain rehabilitation treatment. Increased neural reserve, especially in the parietal areas, is also relevant for the compensatory mechanisms activated by rehabilitative treatment. These data are relevant to support clinical decision by identifying target patients with high probability of success after rehabilitative programs on cognitive and behavioral functioning.

Prevalence, risk and protective factors for mild cognitive impairment in a population-based study of Singaporean elderly

The prevalence of dementia has been widely reported, and its potential risk and protective factors are well-characterized. However, there is a scarcity of related information regarding mild cognitive impairment (MCI). Thus this population-based study aimed to determine the prevalences of MCI and its subtypes, as well as to identify the risk and protective factors for MCI in the Chinese elderly population of Singapore. Results showed that the overall prevalence of MCI was 12.5%, while the gender-adjusted prevalence of MCI was 12.3%. Gender was found to be significantly associated with the subtypes of MCI, with males more likely to have amnestic MCI and females more likely to have non-amnestic MCI. Older age, lower educational levels, lower social activity levels, depression, hypertension, hyperlipidemia, diabetes and stroke were found to be risk factors for MCI in univariate analysis. However, multivariable analysis showed that only hypertension and stroke were the significant risk factors for MCI. Higher educational levels and active social engagements were significant protective factors for MCI in multivariable analysis. Age and depression had boundary significant associations with the prevalence of MCI. After adjusting for gender, the influence of hypertension, stroke, social engagement, age and depression on MCI remained unchanged, except that education became a boundary significant lower risk factor of MCI development. In conclusion, this study presented the prevalence, risk and protective factors for MCI among Singaporean Chinese older adults, which facilitates the screening of vulnerable groups for MCI.

Prevalence of Mild Cognitive Impairment in the Lothian Birth Cohort 1936

BACKGROUND

The Lothian Birth Cohort 1936 (LBC1936) is a highly phenotyped longitudinal study of cognitive and brain ageing. Given its substantial clinical importance, we derived an indicator of mild cognitive impairment (MCI) and amnestic and nonamnestic subtypes at 3 time points.

METHODS

MCI status was derived at 3 waves of the LBC1936 at ages 76 (n=567), 79 (n=441), and 82 years (n=341). A general MCI category was derived as well as amnestic MCI (aMCI) and nonamnestic MCI (naMCI). A comparison was made between MCI derivations using normative data from the LBC1936 cohort versus the general UK population.

RESULTS

MCI rates showed a proportional increase at each wave between 76 and 82 years from 15% to 18%. Rates of MCI subtypes also showed a proportional increase over time: aMCI 4% to 6%; naMCI 12% to 16%. Higher rates of MCI were found when using the LBC1936 normative data to derive MCI classification rather than UK-wide norms.

CONCLUSIONS

We found that MCI and aMCI rates in the LBC1936 were consistent with previous research. However, naMCI rates were higher than expected. Future LBC1936 research should assess the predictive factors associated with MCI prevalence to validate previous findings and identify novel risk factors.

[Cognitive impairment in patients with cardiovascular risk: DECOG study]

OBJECTIVE

To evaluate the correlation between cardiovascular risk factors (CRF) and mild cognitive impairment (MCI) in the primary care setting.

MATERIALS AND METHODS

Observational, cross-sectional and multicenter study conducted in the setting of primary care. Information regarding demographic variables, CRF, comorbidities, and cognitive impairment determined by Mini-Mental State Examination (MMSE) score was collected. These data were correlated by multivariate analysis.

RESULTS

Data from a total of 458 patients were collected. CRFs significantly negative correlated with MCI were patient age, presence of cardiovascular disease, family history of dyslipemia, diastolic blood pressure and cholesterol levels; while factors such as education level and folic acid levels were significant and positive related to higher MMSE scores.

CONCLUSIONS

This study confirms that the presence of CRF impacts on MCI development, already detectable in the primary care setting. High cholesterol levels and high blood pressure are key elements in MCI, and therefore, measures to control these two conditions from primary care should be reinforced in order to stop the development of dementias.

Diet-Cognition Associations Differ in Mild Cognitive Impairment Subtypes

Cognitive function is not generally associated with diet, and there is debate over that association. Moreover, little is known about such associations with the specific cognitive domains and subtypes of mild cognitive impairment (MCI). We analyzed data of 4309 Chinese adults aged 55 and over from the Community-based Cohort Study on Nervous System Diseases from 2018–2019. Dietary habits were assessed at inclusion using a validated semi-quantitative food frequency questionnaire. Cognitive function of the participants was measured by using the Montreal Cognitive Assessment. Analyses were performed using multiple logistic regression and quantile regression with adjustment for socio-demographic, lifestyle, and health-related factors. Compared with normal cognition participants, those with a worse cognition state were characterized as being an older age and lower economic level. After adjustment for potential factors, participants with higher consumption of rice, legumes, fresh vegetables, fresh fruit, pork, poultry, fish, and nuts tended to have higher scores of global cognitive function and domains, and to have lower odds of MCI, while those with higher consumption levels of wheat and eggs had worse cognition, compared with the corresponding bottom consumption level of each food. Participants with a medium consumption level of beef or mutton had 57% (OR: 1.57, 95%CI: 1.07–2.32) higher odds of aMCI-SD, whereas they had 50% (OR: 0.50, 95%CI: 0.34–0.73) lower odds of naMCI-MD. Similarly, the highest consumption level of dairy was positively associated with the odds of aMCI-SD (OR:1.51, 95%CI:1.00–2.29), but inversely linked to the odds of naMCI-SD (OR: 0.60, 95%CI: 0.38–0.93) and naMCI-MD (OR: 0.49, 95%CI: 0.29–0.82). Most diet global cognitive benefits were observed to be associated with the preexisting higher consumption of rice, legumes, fresh vegetables, fresh fruit, meat, and nuts. In addition, the heterogeneity of associations between the consumption of certain foods and MCI subtypes was observed among Chinese adults aged over 55 years. These cross-sectional observations require validation in prospective studies.

Clinical Utility of a Reaction-Time Attention Task in the Evaluation of Cognitive Impairment in Elderly with High Educational Disparity

BACKGROUND

The Clinical Dementia Rating (CDR) scale is commonly used to stage cognitive impairment, despite having educational limitations. In elderly with low education, a previous study has shown that intraindividual variability of reaction time (CV) and commission errors (CE), measured using a culture-free Go/No-Go task, can reliably distinguish early Alzheimer's disease (AD) from mild cognitive impairment (MCI) and healthy controls.

OBJECTIVE

We aimed to extend the clinical utility of this culture-free Go/No-Go task in a sample with high educational disparity.

METHODS

One hundred and ten participants with a wide range of years of formal education (0-14 years) were randomly selected from a geriatric unit and divided based on their CDR scores into cognitively unimpaired (CDR = 0), MCI (CDR = 0.5), and early AD (CDR = 1). All underwent a 90-s reaction-time test that measured the variables previously found to predict CDR in low educated elderly. Here we added years of formal education (educational level) to the model. Multivariate analyses compared differences in group means using educational level as confounding factor. A confirmatory discriminant analyses was performed, to assess if CDR scores could be predicted by the two Go/No-Go variables in a sample with high educational disparity.

RESULTS

Over all three groups, differences in both CE and CV reached statistical significance (p < 0.05). The discriminant analysis demonstrated that CV and CE discriminated cognitively impaired from cognitively normal elderly. These results remained similar when discriminating MCI from cognitively unimpaired elderly.

CONCLUSION

The Go/No-Go task reliably discriminates elderly with MCI from elderly without cognitive impairment independent of educational disparity.

Middle-age dementia risk scores and old-age cognition: a quasi-experimental population-based twin study with over 20-year follow-up

BACKGROUND

Middle-age risk scores predict cognitive impairment, but it is not known if these associations are evident when controlling for shared genetic and environmental factors. Using two risk scores, self-report educational-occupational score and Cardiovascular Risk Factors, Aging and Dementia (CAIDE), we investigated if twins with higher middle-age dementia risk have poorer old-age cognition compared with their co-twins with lower risk.

METHODS

We used a population-based older Finnish Twin Cohort study with middle-age questionnaire data (n=15 169, mean age=52.0 years, SD=11.8) and old-age cognition measured via telephone interview (mean age=74.1, SD=4.1, n=4302). Between-family and within-family linear regression analyses were performed.

RESULTS

In between-family analyses (N=2359), higher educational-occupational score was related to better cognition (B=0.76, 95% CI 0.69 to 0.83) and higher CAIDE score was associated with poorer cognition (B=-0.73, 95% CI -0.82 to -0.65). Within twin-pair differences in educational-occupational score were significantly related to within twin-pair differences in cognition in dizygotic (DZ) pairs (B=0.78, 95% CI 0.25 to 1.31; N=338) but not in monozygotic (MZ) pairs (B=0.12, 95% CI -0.44 to 0.68; N=221). Within twin-pair differences in CAIDE score were not related to within twin-pair differences in cognition: DZ B=-0.38 (95% CI -0.90 to 0.14, N=343) and MZ B=-0.05 (95% CI -0.59 to 0.49; N=226).

CONCLUSION

Middle-age dementia risk scores predicted old-age cognition, but within twin-pair analyses gave little support for associations independent of shared environmental and genetic factors. Understanding genetic underpinnings of risk score-cognition associations is important for early detection of dementia and designing intervention trials.

Strategies for the use of Ginkgo biloba extract, EGb 761® , in the treatment and management of mild cognitive impairment in Asia: Expert consensus

BACKGROUND

Mild cognitive impairment (MCI) is a neurocognitive state between normal cognitive aging and dementia, with evidence of neuropsychological changes but insufficient functional decline to warrant a diagnosis of dementia. Individuals with MCI are at increased risk for progression to dementia; and an appreciable proportion display neuropsychiatric symptoms (NPS), also a known risk factor for dementia. Cerebrovascular disease (CVD) is thought to be an underdiagnosed contributor to MCI/dementia. The Ginkgo biloba extract, EGb 761® , is increasingly being used for the symptomatic treatment of cognitive disorders with/without CVD, due to its known neuroprotective effects and cerebrovascular benefits.

AIMS

To present consensus opinion from the ASian Clinical Expert group on Neurocognitive Disorders (ASCEND) regarding the role of EGb 761® in MCI.

MATERIALS & METHODS

The ASCEND Group reconvened in September 2019 to present and critically assess the current evidence on the general management of MCI, including the efficacy and safety of EGb 761® as a treatment option.

RESULTS

EGb 761® has demonstrated symptomatic improvement in at least four randomized trials, in terms of cognitive performance, memory, recall and recognition, attention and concentration, anxiety, and NPS. There is also evidence that EGb 761® may help delay progression from MCI to dementia in some individuals.

DISCUSSION

EGb 761® is currently recommended in multiple guidelines for the symptomatic treatment of MCI. Due to its beneficial effects on cerebrovascular blood flow, it is reasonable to expect that EGb 761® may benefit MCI patients with underlying CVD.

CONCLUSION

As an expert group, we suggest it is clinically appropriate to incorporate EGb 761® as part of the multidomain intervention for MCI.

Prevalence of mild cognitive impairment in community-dwelling Chinese populations aged over 55 years: a meta-analysis and systematic review

Background

Mild cognitive impairment (MCI) is an intermediate phase between normal cognitive ageing and overt dementia, with amnesic MCI (aMCI) being the dominant subtype. This study aims to synthesise the prevalence results of MCI and aMCI in community-dwelling populations in China through a meta-analysis and systematic review.

Methods

The study followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) protocol. English and Chinese studies published before 1 March 2020 were searched from ten electronic bibliographic databases. Two reviewers screened for relevance of the studies against the pre-defined inclusion and exclusion criteria and assessed the quality of the included studies using the Risk of Bias Tool independently. A random-effect model was adopted to estimate the prevalence of MCI and aMCI, followed by sub-group analyses and meta-regression. Sensitivity and publication bias tests were performed to verify the robustness of the meta-analyses.

Results

A total of 41 studies with 112,632 participants were included in the meta-analyses. The Chinese community-dwelling populations over 55 years old had a pooled prevalence of 12.2% [95% confidence interval (CI): 10.6, 14.2%] for MCI and 10.9% [95% CI, 7.7, 15.4%] for aMCI, respectively. The prevalence of MCI increased with age. The American Psychiatric Association’s Diagnostic tool (DSM-IV) generated the highest MCI prevalence (13.5%), followed by the Petersen criteria (12.9%), and the National Institute on Aging Alzheimer’s Association (NIA-AA) criteria (10.3%). Women, rural residents, and those who lived alone and had low levels of education had higher MCI prevalence than others.

Conclusion

Higher MCI prevalence was identified in community-dwelling older adult populations in China compared with some other countries, possibly due to more broadened criteria being adopted for confirming the diagnosis. The study shows that aMCI accounts for 66.5% of MCI, which is consistent with findings of studies undertaken elsewhere.

Systematic review registration number

PROSPERO CRD42019134686.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-020-01948-3.

Skeletal Muscle Health and Cognitive Function: A Narrative Review

Sarcopenia is the loss of skeletal muscle mass and function with advancing age. It involves both complex genetic and modifiable risk factors, such as lack of exercise, malnutrition and reduced neurological drive. Cognitive decline refers to diminished or impaired mental and/or intellectual functioning. Contracting skeletal muscle is a major source of neurotrophic factors, including brain-derived neurotrophic factor, which regulate synapses in the brain. Furthermore, skeletal muscle activity has important immune and redox effects that modify brain function and reduce muscle catabolism. The identification of common risk factors and underlying mechanisms for sarcopenia and cognition may allow the development of targeted interventions that slow or reverse sarcopenia and also certain forms of cognitive decline. However, the links between cognition and skeletal muscle have not been elucidated fully. This review provides a critical appraisal of the literature on the relationship between skeletal muscle health and cognition. The literature suggests that sarcopenia and cognitive decline share pathophysiological pathways. Ageing plays a role in both skeletal muscle deterioration and cognitive decline. Furthermore, lifestyle risk factors, such as physical inactivity, poor diet and smoking, are common to both disorders, so their potential role in the muscle-brain relationship warrants investigation.

Detection of Cognitive Dysfunction in Elderly with a Low Educational Level Using a Reaction-Time Attention Task

Background: Scales for cognitive deterioration usually depend on education level. Objective: We aimed to study the clinical utility of a culture-free Go/No-Go task in a multi-ethnic cohort with low education level. Methods: Sixty-four participants with less than 4 years of formal education were included and divided on the basis of their Clinical-Dementia-Rate scores (CDR) into cognitively unimpaired (CDR = 0), mild cognitive impairment (MCI; CDR = 0.5), and early Alzheimer’s disease (AD, CDR = 1). All underwent a 90-s Continuous Visual Attention Test. This test consisted of a 90-s Go/No-go task with 72 (80%) targets and 18 (20%) non-targets. For each participant, reaction times and intraindividual variability of reaction times of all correct target responses, as well as the number of omission and commission errors were evaluated. Coefficient of variability was calculated for each participant by dividing the standard deviation of the reaction times by the mean reaction time. A MANCOVA was performed to examine between-group differences using age and sex as covariates. Discriminate analysis was performed to find the most reliable test-variable to discriminate the three groups. Results: Commission error, intraindividual variability of reaction time, and coefficient of variability progressively worsened with increasing CDR level. Discriminant analysis demonstrated that coefficient of variability was the best discriminant factor, followed by intraindividual variability of reaction time and commission error. Conclusion: The Go/No-Go task was able to discriminate people with MCI or early AD from controls in the setting of illiteracy.

A systematic review of the prevalence of mental and neurocognitive disorders amongst older adults’ populace in Egypt

Background

Mental and neurocognitive disorders are the leading cause of disabilities amongst the older adult populace worldwide. The population of the older adult in Egypt is fast growing. The national census in 2017 revealed a 2.56% increase in the older adult population from the 2006 census, and these figures are expected to double by year 2031. This study aims to review current evidence about the prevalence of mental and neurocognitive disorders amongst older adult population in Egypt.

Results

A systematic review was carried out, and 16 studies met the inclusion criteria outlined in this study. Four main mental and neurocognitive disorders were identified: depression, anxiety, cognitive impairment and dementia. The reported prevalence of depression, anxiety, dementia and cognitive impairment are 23.7–74.5%, 14.2–72%, 3.66–39.2% and 1.74–51.4%, respectively. Anxiety and depression were positively correlated with the female gender, increasing age and lower educational status. Also, cognitive impairment and dementia were positively correlated with age, illiteracy or low education. However, there appears to be inconsistencies in the diagnostic tools used.

Conclusion

Egypt aging population is growing, and this research brings to forefront the scale of mental and neurocognitive disorders amongst the older adult population. This may help ensure evidence-based initiatives are put in place and priority is given to resource allocation for geriatric mental and neurocognitive disorders in Egypt.

Systematic review registration

PROSPERO CRD42018114831

Carvalho O, Barros H. Global Cognitive Impairment Prevalence and Incidence in Community Dwelling Older Adults-A Systematic Review

(1) Background: We proposed to review worldwide estimates of cognitive impairment prevalence and incidence in adults older than 50 years of age living in the community. (2) Methods: Systematic searches were performed in January 2019 using MEDLINE/PubMed. Articles were selected if they referred to cognitive impairment, prevalence, incidence, elders, and population or community-based studies. Analysis, aggregated by different methodologic features, was performed. (3) Results: Prevalence (80 studies) ranged between 5.1% and 41% with a median of 19.0% (25th percentile = 12.0%; 75th percentile = 24.90%). Incidence (11 studies) ranged from 22 to 76.8 per 1000 person-years with a median of 53.97 per 1000 person-years (25th percentile = 39.0; 75th percentile = 68.19). No statistically significant effects were found except for inclusion age. (4) Conclusion: We propose that the homogenization and clarification of the definition of what constitutes cognitive impairment are essential to refine the epidemiological understanding of this entity. The results of this review reinforce the importance of adherence to standardized cut-off scores for cognitive tests to promote study comparability.

The Prevalence of Mild Cognitive Impairment in a Convenience Sample of 202 Gulf War Veterans

Gulf War Illness (GWI) is a chronic, multisymptom disorder estimated to affect approximately 25–32% of Gulf War veterans (GWVs). Cognitive dysfunction is a common symptom of GWI. On the continuum of cognitive decline, mild cognitive impairment (MCI) is conceptualized as a transitional phase between normal aging and dementia. Individuals with MCI exhibit cognitive decline but have relatively spared activities of daily function and do not meet criteria for dementia. The current study sought to investigate the prevalence of MCI in a convenience sample of 202 GWVs (median age: 52 years; 18% female). Twelve percent of the sample (median age: 48 years) had MCI according to an actuarial neuropsychological criterion, a rate materially higher than expected for this age group. GWVs with MCI also had a smaller hippocampal volume and a thinner parietal cortex, higher rates of current posttraumatic stress disorder and major depressive disorder compared to GWVs without MCI. Because people with MCI are more likely to progress to dementia compared to those with normal cognition, these results may portend future higher rates of dementia among deployed GWVs.

Late-life personality traits, cognitive impairment, and mortality in a population-based cohort

OBJECTIVES

We examined longitudinal associations between late-life personality traits and cognitive impairment, dementia, and mortality in the population-based Cardiovascular Risk Factors, Aging and Dementia (CAIDE) Study.

METHODS

Anger expression and trait anger (State-Trait Anger Expression Inventory), anxiety (State-Trait Anxiety Inventory), and sense of coherence (Sense of Coherence Scale) were assessed at the 1998 CAIDE visit (1266 cognitively normal individuals, mean age 71.0 years). Totally, 582 participants had complete re-examination in 2005-2008 (105 mild cognitive impairment, MCI; and 29 dementia). National registers data until 2008 were also used for both participants and nonparticipants to ascertain incident dementia (96 cases) and mortality (227 died). Analyses were adjusted for age, sex, education, follow-up time, cardiovascular and lifestyle factors, and depressive symptoms.

RESULTS

Higher anxiety was associated with higher risk of MCI/dementia (OR 1.68, 95% CI 1.07-2.63) and death (HR 1.46, 95% CI 1.08-1.98). High sense of coherence was associated with lower mortality (HR 0.65, 95% CI 0.45-0.93). These associations were attenuated after accounting for depressive symptoms (OR 1.57, 95% CI 0.96-2.58 for anxiety-MCI/dementia; HR 1.35, 95% CI 0.97-1.86 for anxiety-mortality; and HR 0.68, 95% CI 0.45-1.04 for sense of coherence-mortality). Trait anger was associated with higher dementia risk even after adjustments (HR 1.90, 95% CI 1.14-3.18).

CONCLUSIONS

Anxiety was linked to worse cognitive outcome and mortality and sense of coherence to lower mortality. Depressive symptoms attenuated the associations. As a novel finding, trait anger was connected to dementia risk. These findings emphasize the importance of personality-related risk factors for dementia and mortality. J Am Geriatr Soc 68:-, 2020.

Timely Detection of Mild Cognitive Impairment in Italy: An Expert Opinion

Mild cognitive impairment (MCI) generally evolves in a gradually progressive decline in memory and non-memory cognitive domains that may eventually decay to dementia. This process might be preventable by improving early detection of the MCI syndrome followed by proper and timely interventions. The aim of this work was providing helpful indications for a standardized early diagnosis of MCI, mainly focusing on the Italian elderly population. We reviewed here MCI epidemiology and classification, as well as the most recent advancements in early detection of the patient with MCI in the Italian scenario. Specialist centers in connection with general practitioners (GPs) have been established across the country and designated as Centers for Cognitive Disorders and Dementia (CDCD). CDCDs are dedicated to the diagnosis and management of patients for all forms of dementia across all the complex staging spectrum. New tools were made available by the advancements of imaging techniques and of the research on biomarkers, leading to novel approaches based on the combination of imaging and biomarker detection, to improve accuracy and effectiveness in the early diagnosis of MCI. Moreover, patient genotyping, alone or in combination with other techniques, was also revealed as a promising method in evaluating and preventing MCI progression. We recommend the introduction of all these novel tools in the diagnostic practice of the specialist centers and that further efforts and resources are spent into the research of the most effective techniques and biomarkers to be introduced as first-level tests into the practice of early diagnosis of MCI.

Effectiveness of Exergaming in Improving Cognitive and Physical Function in People With Mild Cognitive Impairment or Dementia: Systematic Review

BACKGROUND

Individuals with mild cognitive impairment and dementia have impaired physical and cognitive functions, leading to a reduced quality of life compared with those without such impairment. Exergaming, which is defined as a combination of exercise and gaming, is an innovative, fun, and relatively safe way to exercise in a virtual reality or gaming environment. Therefore, exergaming may help people living with mild cognitive impairment or dementia to overcome obstacles that they may experience regarding regular exercise and activities.

OBJECTIVE

The aim of this systematic review was to review studies on exergaming interventions administered to elderly individuals with mild cognitive impairment and dementia, and to summarize the results related to physical and cognitive functions such as balance, gait, executive function, and episodic memory.

METHODS

We searched Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, PsycINFO, Amed, and Nursing Database for articles published from the inception of the respective databases to January 2019. We included all clinical trials of exergaming interventions in individuals with mild cognitive impairment and dementia for review. The risk of bias was independently evaluated by two reviewers using the Cochrane Collaboration and Risk of Bias in Non-randomized Studies of Interventions tools.

RESULTS

Ten studies involving 702 participants were included for review. There was consistent evidence from 7 studies with a low risk of bias showing statistically significant effects of exergaming on cognitive functioning in people with mild cognitive impairment and dementia. With respect to physical function, 3 of 5 full-scale studies found positive results, and the intensity of most games was classified as moderate.

CONCLUSIONS

Overall, exergaming is an innovative tool for improving physical and cognitive function in people with mild cognitive impairment or dementia, although there is high heterogeneity among studies in terms of the duration, frequency, and gaming platform used. The quality of the included articles was moderate to high. More high-quality studies with more accurate outcome indicators are needed for further exploration and validation of the benefits of exergaming for this population.

A novel conversion prediction method of MCI to AD based on longitudinal dynamic morphological features using ADNI structural MRIs

Mild cognitive impairment (MCI) is a pre-existing state of Alzheimer's disease (AD). An accurate prediction on the conversion from MCI to AD is of vital clinical significance for potential prevention and treatment of AD. Longitudinal studies received widespread attention for investigating the disease progression, though most studies did not sufficiently utilize the evolution information. In this paper, we proposed a cerebral similarity network with more progression information to predict the conversion from MCI to AD efficiently. First, we defined the new dynamic morphological feature to mine longitudinal information sufficiently. Second, based on the multiple dynamic morphological features the cerebral similarity network was constructed by sparse regression algorithm with optimized parameters to obtain better prediction performance. Then, leave-one-out cross-validation and support vector machine (SVM) were employed for the training and evaluation of the classifiers. The proposed methodology obtained a high accuracy of 92.31% (Sensitivity = 100%, Specificity = 82.86%) in a three-year ahead prediction of MCI to AD conversion. Experiment results suggest the effectiveness of the dynamic morphological feature, serving as a more sensitive biomarker in the prediction of MCI conversion.

Elevated blood neutrophil to lymphocyte ratio in older adults with cognitive impairment

BACKGROUND

Previous studies have assessed the association of neutrophil to lymphocyte ratio (NLR) with cognitive impairment (COI) in clinical settings. Whether NLR is associated with COI among free-living seniors at population level remains unknown.

OBJECTIVES

We aimed to assess the relationship between NLR and COI among community-dwelling older adults and the predictive value of NLR for COI screening in the community.

METHODS

Data of 4579 older adults aged 60 or older in Weitang Geriatric Diseases study, a community-based cross-sectional study conducted in Suzhou located in the east part of China, were analyzed. The NLR was calculated as the absolute neutrophil count divided by the absolute lymphocyte count. Cognitive function of the participants was assessed using the Abbreviated Mental Test.

RESULTS

Compared to those in the first quartile of NLR, older adults in the 4th quartile of NLR had a greater risk of COI (odds ratio = 1.34, 95 % confidence interval = 1.06-1.69). Elevated NLR quartile was associated with increasing risk of COI (p value for trend = 0.02). Addition of NLR to the conventional risk factors model could improve the correct reclassification of COI about 9.0 % (p = 0.02) and integrated discrimination improvement value was 0.0012 (p = 0.09).

CONCLUSIONS

We found that elevated NLR was associated with an increased risk of COI and whether NLR may act as a clinically relevant predictor for COI among community-dwelling older adults could not be determined.

Tanshinone IIA Alleviates CCL2-Induced Leaning memory and Cognition Impairment in Rats: A Potential Therapeutic Approach for HIV-Associated Neurocognitive Disorder

Chemokine CC motif ligand 2 (CCL2) is one of the most recognized proinflammatory chemokines, and the expression of CCL2 in the cerebrospinal fluid of patients infected with HIV-1 is significantly higher than that of healthy people. As such, it is seen as an important cause of HIV-associated neurocognitive disorder (HAND). Our previous investigation has confirmed the pathological role of CCL2 in mediating brain damage leading to cognitive dysfunction. Currently, however, research on therapeutic drugs for the central nervous system targeting CCL2 is very limited. Our present study used brain stereotactic technology to induce cognitive impairment in rats by injecting CCL2 (5 ng) into the bilateral hippocampus. To investigate the protective effect and mechanism of Tanshinone IIA (25, 50, 75 mg/kg/d) on CCL2-induced learning memory and cognitive impairment in rats, we performed the Morris water maze (MWM) and novel object recognition tests (NORT) on the rats. The results showed that Tanshinone IIA significantly alleviated CCL2-induced learning memory and cognitive dysfunction. Further studies on the hippocampal tissue of the rats revealed that Tanshinone IIA treatment significantly increased the activity of SOD and GSH-Px while the level of MDA decreased compared to the model group. Additionally, the relative expression of apoptosis-associated genes caspase-3, caspase-8, and caspase-9 and inflammation-associated genes IL-1β and IL-6 in Tanshinone IIA-treated rats was lower than that in model rats. Finally, we confirmed hippocampal neuron loss and apoptosis by Nissl staining and TdT-mediated dUTP Nick end labeling (TUNEL). Taken together, these data imply that Tanshinone IIA can ameliorate CCL2-induced learning memory and cognitive impairment by impacting oxidative stress, inflammation, and apoptosis. Tanshinone IIA may be a potential therapeutic agent for the treatment of HAND.

Age-specific changes in cognitive function

Currently, the number of cases of pathological aging of the central nervous system, represented by a violation of cognitive functions, is increasing. But there is a social request to prolong the physical and mental activity of older people. The study of the dynamics of cognitive aging is timely and relevant. The article contains a report on a cohore non-repeating study of higher brain functions at various age periods. 148 people involved. Their age is 27 -74 years. They are right handed. We applied the screening neuropsychological method. Statistical data processing was performed using SPSS Statistics 17.0 (Mann-Whitney U-test). The dynamic heterogeneity of the cognitive profile during aging was revealed. The deterioration in the performance of the graphomotor test was the most age-specific. In older study participants, a decrease in the visual gnosis test correlated with a decrease in non-verbal intelligence. The decrease in executive functions correlated with the growth of neurodynamic disorders in elderly study participants. The results obtained are useful for differentiating normative and pathological aging of the central nervous system.

The effects of acupuncture on cognitive deficits in transgenic mouse studies of mild cognitive impairment and Alzheimer's disease: Study protocol of a systematic review

BACKGROUND

Mild cognitive impairment (MCI) and Alzheimer's disease (AD) are neurodegenerative diseases associated with aging. The major clinical features of both are progressive memory loss and progressive cognitive loss. The objective of this systematic review protocol is to provide the methods for evaluating the effectiveness of acupuncture in the treatment on cognitive deficits in transgenic mouse.

METHODS AND ANALYSIS

We will search the electronic databases of PubMed, Web of Science, Embase, PsycINFO, as well as the Chinese databases such as Chinese Biomedicine Literature (CBM), Chinese Medical Current Content (CMCC), Chinese Scientific Journal Database (VIP), WanFang Database and China National Knowledge Infrastructure (CNKI) from their inceptions to July 2019. RevMan 5.3 software will be used for the data synthesis and the quality of each study was assessed independently by use of the CAMARADES checklist.

RESULTS

This review will provide a high-quality synthesis based on present evidence of acupuncture treatment for AD and MCI in transgenic mouse models.

CONCLUSIONS

This systematic review will provide evidence for weather acupuncture is an effective intervention for AD and MCI in transgenic mouse models.

ETHICS AND DISSEMINATION

Ethical approval is not necessary since this protocol is only for systematic review and does not involve privacy data or conduct an animal experiment. This protocol will be disseminated by a peer-review journal or conference presentation.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42019142985.

STRENGTHS AND LIMITATIONS OF THIS STUDY

This systematic review will be the first to provide new knowledge underlying the effectiveness to improve cognitive function of acupuncture treatment for AD and MCI in transgenic mouse models. The result of this systematic review may provide experimental and theoretical basis for the future clinical application of acupuncture in the treatment of AD.The limitation of this systematic review may come from language barriers, because only English and Chinese can be included. Also, this study includes various kinds of acupuncture treatments which may result in essential heterogeneity.

Validation of a digitally delivered visual paired comparison task: reliability and convergent validity with established cognitive tests

Alzheimer's disease (AD) affects the memory and cognitive function of approximately 5.7 million Americans. Early detection subsequently allows for earlier treatment and improves outcomes. Currently, there exists a validated 30-min eye-tracking cognitive assessment (VPC-30) for predicting AD risk. However, a shorter assessment would improve user experience and improve scalability. Thus, the purposes were to (1) determine convergent validity between the 5-min web camera-based eye-tracking task (VPC-5) and VPC-30, (2) examine the relationship between VPC-5 and gold-standard cognitive tests, and (3) determine the reliability and stability of VPC-5. This prospective study included two healthy cohorts: older adults (65+ years, n = 20) and younger adults (18-46 years, n = 24). Participants were tested on two separate occasions. Visit 1 included the Montreal Cognitive Assessment (MoCA), Digit Symbol Coding test (DSC), NIH Toolbox Cognitive Battery (NIHTB-CB), VPC-30, and VPC-5. Visit 2 occurred at least 14 days later; participants completed the VPC-5, DSC, NIHTB-CB, and dual-task walking assessments (DT). VPC-30 significantly correlated with VPC-5 at the first (p < .001) and second (p = .001) time points. VPC-5 and DSC (p < .01) and Pattern Comparison Processing Speed Test (PSPAC) (p = .01) were also correlated on day 1. Significant associations existed between VPC-5 and DSC (p < .001), Flanker Inhibitory Control Test (p = .05), PSPAC (p < .001), and Picture Sequence Memory Test (p = .02) during day 14 testing session. The test retest reliability of VPC-5 was significant (p < .001). VPC-5 displayed moderate convergent validity with the VPC-30 and gold-standard measures of cognition, while demonstrating strong stability, suggesting it is a valuable assessment for monitoring memory function.

Detection of mild cognitive impairment in a community-dwelling population using quantitative, multiparametric MRI-based classification

Early and accurate mild cognitive impairment (MCI) detection within a heterogeneous, nonclinical population is needed to improve care for persons at risk of developing dementia. Magnetic resonance imaging (MRI)-based classification may aid early diagnosis of MCI, but has only been applied within clinical cohorts. We aimed to determine the generalizability of MRI-based classification probability scores to detect MCI on an individual basis within a general population. To determine classification probability scores, an AD, mild-AD, and moderate-AD detection model were created with anatomical and diffusion MRI measures calculated from a clinical Alzheimer's Disease (AD) cohort and subsequently applied to a population-based cohort with 48 MCI and 617 normal aging subjects. Each model's ability to detect MCI was quantified using area under the receiver operating characteristic curve (AUC) and compared with an MCI detection model trained and applied to the population-based cohort. The AD-model and mild-AD identified MCI from controls better than chance level (AUC = 0.600, p = 0.025; AUC = 0.619, p = 0.008). In contrast, the moderate-AD-model was not able to separate MCI from normal aging (AUC = 0.567, p = 0.147). The MCI-model was able to separate MCI from controls better than chance (p = 0.014) with mean AUC values comparable with the AD-model (AUC = 0.611, p = 1.0). Within our population-based cohort, classification models detected MCI better than chance. Nevertheless, classification performance rates were moderate and may be insufficient to facilitate robust MRI-based MCI detection on an individual basis. Our data indicate that multiparametric MRI-based classification algorithms, that are effective in clinical cohorts, may not straightforwardly translate to applications in a general population.

Evaluation of statins impacts on cognitive function among diabetic patients

AIMS

The study was intended to evaluate the association of cognitive impairment with statins therapy among diabetic outpatients.

METHODS

Mini-Addenbrooke's Cognitive Examination (M-ACE) was conducted for 280 cases in a cross-sectional study at Hospital Pulau Pinang. M-ACE score is 30, and the cut-off score for mild cognitive impairment is ≤ 21 and ≤ 16 for dementia.

RESULTS

The cognitive impairment was distributed among 59 (55.1%) patients with mild cognitive impairment and 48 (44.9%) patients with dementia. From 177 patients using statins, about 80 (45.2%) cases had cognitive impairment. While from 103 statins non-users, only 27 (26.2%) had cognitive impairment. The relative risk of cognitive impairment associated with statins use in diabetic patients is (RR: 1.72, 95% CI: 1.2-2.48) and the excess relative risk is 72.4%. The absolute risk is 19%, and the number needed to harm is 6. Spearman's test indicated a positive association between statins usage and cognitive impairment incidence (r: 0.188, p-value: 0.002). However, Spearman's test showed a non-significant correlation amongst statins and dementia incidence (P-value: 0.587, RR: 1.16, 95% CI: 0.67-2.02).

CONCLUSIONS

Statins therapy has a higher association with cognitive impairment risk than statins-free treatment; however, there is no association between statin use and dementia incidence among diabetic patients.

A cross-sectional study to assess prevalence and factors associated with mild cognitive impairment among older adults in an urban area of Kerala, South India

OBJECTIVES

To assess the prevalence and factors associated with mild cognitive impairment (MCI) among older adults in an urban area of South India.

SETTING

The study was conducted in the capital city of Thiruvananthapuram in the South Indian state of Kerala.

PARTICIPANTS

The study participants were community-dwelling individuals aged 60 years and above.

PRIMARY OUTCOME MEASURE

MCI was the primary outcome measure and was defined using the criteria by European Alzheimer's Disease Consortium. Cognitive assessment was done using the Malayalam version of Addenbrooke's Cognitive Examination tool. Data were also collected on sociodemographic variables, self-reported comorbidities like hypertension and diabetes, lifestyle factors, depression, anxiety and activities of daily living.

RESULTS

The prevalence of MCI was found to be 26.06% (95% CI of 22.12 to 30.43). History of imbalance on walking (adjusted OR 2.75; 95 % CI of 1.46 to 5.17), presence of depression (adjusted OR 2.17, 95 % CI of 1.21 to 3.89), anxiety (adjusted OR 2.22; 95 % CI of 1.21 to 4.05) and alcohol use (adjusted OR 1.99; 95 % CI of 1.02 to 3.86) were positively associated with MCI while leisure activities at home (adjusted OR 0.33; 95 % CI of 0.11 to 0.95) were negatively associated.

CONCLUSION

The prevalence of MCI is high in Kerala. It is important that the health system and the government take up urgent measures to tackle this emerging public health issue.

Differential Methylation in APOE (Chr19; Exon Four; from 44,909,188 to 44,909,373/hg38) and Increased Apolipoprotein E Plasma Levels in Subjects with Mild Cognitive Impairment

BACKGROUND

Biomarkers are essential for identification of individuals at high risk of mild cognitive impairment (MCI) for potential prevention of dementia. We investigated DNA methylation in the APOE gene and apolipoprotein E (ApoE) plasma levels as MCI biomarkers in Colombian subjects with MCI and controls.

METHODS

In total, 100 participants were included (71% women; average age, 70 years; range, 43⁻91 years). MCI was diagnosed by neuropsychological testing, medical and social history, activities of daily living, cognitive symptoms and neuroimaging. Using multivariate logistic regression models adjusted by age and gender, we examined the risk association of MCI with plasma ApoE and APOE methylation.

RESULTS

MCI was diagnosed in 41 subjects (average age, 66.5 ± 9.6 years) and compared with 59 controls. Elevated plasma ApoE and APOE methylation of CpGs 165, 190, and 198 were risk factors for MCI (p < 0.05). Higher CpG-227 methylation correlated with lower risk for MCI (p = 0.002). Only CpG-227 was significantly correlated with plasma ApoE levels (correlation coefficient = -0.665; p = 0.008).

CONCLUSION

Differential APOE methylation and increased plasma ApoE levels were correlated with MCI. These epigenetic patterns require confirmation in larger samples but could potentially be used as biomarkers to identify early stages of MCI.

Psoriasis is not associated with cognition, brain imaging markers, and risk for dementia: The Rotterdam Study

BACKGROUND

Based on increased cardiometabolic comorbidities, inflammation, and an overlap in genetics with Alzheimer disease, psoriasis patients might be at risk for cognitive dysfunction and dementia.

OBJECTIVE

To compare cognition, magnetic resonance imaging (MRI)-markers, and dementia risk in psoriasis and nonpsoriasis participants in the population-based Rotterdam Study.

METHODS

We identified 318 psoriasis and 9678 nonpsoriasis participants (mean age 66.1 years, 58% women). The association of psoriasis with cognitive function, mild cognitive impairment, and MRI-markers of brain damage was examined by linear and logistic regression. Dementia risk was calculated using Cox regression. Models were adjusted for age, sex, education, and cardiovascular risk factors.

RESULTS

Cognitive test scores and volumetric, microstructural, focal measures on brain MRI did not differ between psoriasis (28% systemic and ultraviolet treatment) and nonpsoriasis participants, and psoriasis was not associated with mild cognitive impairment (adjusted odd ratio 0.87, 95% confidence interval 0.53-1.43). During 115.000 person-years of follow-up, 810 incident dementia cases (15 among psoriasis patients) occurred. After adjusting for confounders, psoriasis was associated with a lower risk of developing dementia (adjusted hazard ratio 0.50, 95% confidence interval 0.28-0.91).

LIMITATIONS

Limited dementia cases among psoriasis patients.

CONCLUSION

In this population-based study, psoriasis was not associated with preclinical markers or higher dementia risk.

The Prevalence of Mild Cognitive Impairment in China: A Systematic Review

The aim of this study was to analyze the prevalence of mild cognitive impairment (MCI) among the aging population (60 years of age and above) in China. Epidemiological investigations on MCI in online Chinese journals were identified manually using the CQVIP, CNKI, and Wanfang databases. Articles from journals published in English were identified using PubMed and Web of Science. Original studies that included prevalence surveys of MCI were selected. Forty-eight relevant studies were included in the analysis, covering 22 provinces in China. Our results showed that the pooled prevalence of MCI in the older Chinese population was 14.71% (95% confidence interval [CI], 14.50-14.92%). The prevalence was 16.72% (95% CI, 15.68-17.71%) in clinical samples vs. 14.61% (95% CI, 14.40-14.83%) in nonclinical samples (χ2=16.60, P<0.01), and 15.20% (95% CI, 14.91-15.49%) in screened samples vs. 14.16% (95% CI, 13.85-14.46%) in diagnosed samples (χ2=22.11, P<0.01). People of older age, of female sex, or living in rural areas or western China were associated with a higher prevalence of MCI. The prevalence of MCI was high in Chinese older adults, and even higher in those who were older, female, or living in rural areas or western China. Future studies are recommended to address the prevalence of MCI in the other 12 provinces of China. Furthermore, diagnostic assessments should be included in the identification of MCI.

Association Between Later Life Lifestyle Factors and Alzheimer's Disease Biomarkers in Non-Demented Individuals: A Longitudinal Descriptive Cohort Study

BACKGROUND

Lifestyle factors have been associated with the risk of dementia, but the association with Alzheimer's disease (AD) remains unclear.

OBJECTIVE

To examine the association between later life lifestyle factors and AD biomarkers (i.e., amyloid-β 1-42 (Aβ42) and tau in cerebrospinal fluid (CSF), and hippocampal volume) in individuals with subjective cognitive decline (SCD) and mild cognitive impairment (MCI). In addition, to examine the effect of later life lifestyle factors on developing AD-type dementia in individuals with MCI.

METHODS

We selected individuals with SCD (n = 111) and MCI (n = 353) from the DESCRIPA and Kuopio Longitudinal MCI studies. CSF Aβ42 and tau concentrations were assessed with ELISA assay and hippocampal volume with multi-atlas segmentation. Lifestyle was assessed by clinical interview at baseline for: social activity, physical activity, cognitive activity, smoking, alcohol consumption, and sleep. We performed logistic and Cox regression analyses adjusted for study site, age, gender, education, and diagnosis. Prediction for AD-type dementia was performed in individuals with MCI only.

RESULTS

Later life lifestyle factors were not associated with AD biomarkers or with conversion to AD-type dementia. AD biomarkers were strongly associated with conversion to AD-type dementia, but these relations were not modulated by lifestyle factors. Apolipoprotein E (APOE) genotype did not influence the results.

CONCLUSIONS

Later life lifestyle factors had no impact on key AD biomarkers in individuals with SCD and MCI or on conversion to AD-type dementia in MCI.

Putative Dementia Cases Fluctuate as a Function of Mini-Mental State Examination Cut-Off Points

As the population ages, there is a growing need to quickly and accurately identify putative dementia cases. Many cognitive tests are available; among those commonly used are the Cognitive Dementia Rating (CDR) and the Mini-Mental Status Examination (MMSE). The aim of this work was to compare the validity and reliability of these cognitive tests in a primary care based cohort (pcb-Cohort). The MMSE and the CDR were applied to 568 volunteers in the pcb-Cohort. Distinct cut-off points for the MMSE were considered, namely MMSE 27, MMSE 24, and MMSE PT (adapted for the Portuguese population). The MMSE 27 identified the greatest number of putative dementia cases, and, as determined by the ROC curve, it was the most sensitive and specific of the MMSE cut-offs considered. Putative predictive or risk factors identified included age, literacy, depression, and diabetes mellitus (DM). DM has previously been indicated as a risk factor for dementia and Alzheimer's disease. Comparatively, the MMSE 27 cut-off has the greatest sensibility (94.9%) and specificity (66.3%) when compared to MMSE PT and MMSE 24. Upon comparing MMSE and CDR scores, the latter identified a further 146 putative dementia cases, thus permitting one to propose that in an ideal situation, both tests should be employed. This increases the likelihood of identifying putative dementia cases for subsequent follow up work, thus these cognitive tests represent important tools in patient care. Further, this is a significant study for Portuguese populations, where few of these studies have been carried out.

Screening Younger Individuals in a Primary Care Setting Flags Putative Dementia Cases and Correlates Gastrointestinal Diseases with Poor Cognitive Performance

BACKGROUND/AIMS

Diagnosing dementia is challenging in many primary care settings, given the limited human resources and the lack of current diagnostic tools. With this in mind, a primary care-based cohort was established in the Aveiro district of Portugal.

METHODS

A total of 568 participants were evaluated using cognitive tests and APOE genotyping.

RESULTS

The findings revealed a dementia prevalence of 12%. A strong correlation between increasing Clinical Dementia Rating (CDR) scores and education was clearly evident. Other highly relevant risk factors were activities of daily living (ADL), instrumental ADL, aging, depression, gender, the APOE ε4 allele, and comorbidities (depression as well as gastrointestinal, osteoarticular, and neurodegenerative diseases). A hitherto unreported, significant correlation between gastrointestinal disease and high CDR score was clearly observable.

CONCLUSIONS

This study shows the merit of carrying out a dementia screening on younger subjects. Significantly, 71 subjects in the age group of 50-65 years were flagged for follow-up studies; furthermore, these cases with a potentially early onset of dementia were identified in a primary care setting.