Mild cognitive impairment: a concept in evolution

Physical Activity: A Viable Way to Reduce the Risks of Mild Cognitive Impairment, Alzheimer's Disease, and Vascular Dementia in Older Adults

A recent alarming rise of neurodegenerative diseases in the developed world is one of the major medical issues affecting older adults. In this review, we provide information about the associations of physical activity (PA) with major age-related neurodegenerative diseases and syndromes, including Alzheimer's disease, vascular dementia, and mild cognitive impairment. We also provide evidence of PA's role in reducing the risks of these diseases and helping to improve cognitive outcomes in older adults. Finally, we describe some potential mechanisms by which this protective effect occurs, providing guidelines for future research.

Cortical Amyloid Burden Differences Across Empirically-Derived Mild Cognitive Impairment Subtypes and Interaction with APOE ɛ4 Genotype

We examined cortical amyloid-β (Aβ) levels and interactions with apolipoprotein (APOE) ɛ4 genotype status across empirically-derived mild cognitive impairment (MCI) subgroups and cognitively normal older adults. Participants were 583 ADNI participants (444 MCI, 139 normal controls [NC]) with baseline florbetapir positron emission tomography (PET) amyloid imaging and neuropsychological testing. Of those with ADNI-defined MCI, a previous cluster analysis [1] classified 51% (n = 227) of the current sample as amnestic MCI, 8% (n = 37) as dysexecutive/mixed MCI, and 41% (n = 180) as cluster-derived normal (cognitively normal). Results demonstrated that the dysexecutive/mixed and amnestic MCI groups showed significantly greater levels of amyloid relative to the cluster-derived normal and NC groups who did not differ from each other. Additionally, 78% of the dysexecutive/mixed, 63% of the amnestic MCI, 42% of the cluster-derived normal, and 34% of the NC group exceeded the amyloid positivity threshold. Finally, a group by APOE genotype interaction demonstrated that APOE ɛ4 carriers within the amnestic MCI, cluster-derived normal, and NC groups showed significantly greater amyloid accumulation compared to non-carriers of their respective group. Such an interaction was not revealed within the dysexecutive/mixed MCI group which was characterized by both greater cognitive impairment and amyloid accumulation compared to the other participant groups. Our results from the ADNI cohort show considerable heterogeneity in Aβ across all groups studied, even within a group of robust NC participants. Findings suggest that conventional criteria for MCI may be susceptible to false positive diagnostic errors, and that onset of Aβ accumulation may occur earlier in APOE ɛ4 carriers compared to non-carriers.

Nutritional status and body composition by bioelectrical impedance vector analysis: A cross sectional study in mild cognitive impairment and Alzheimer's disease

AIMS

Analysis of nutritional status and body composition in Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI).

METHODS

A cross-sectional study was performed in a University-Hospital setting, recruiting 59 patients with AD, 34 subjects with MCI and 58 elderly healthy controls (HC). Nutritional status was assessed by anthropometric parameters (body mass index; calf, upper arm and waist circumferences), Mini Nutritional Assessment (MNA) and body composition by bioelectrical impedance vector analysis (BIVA). Variables were analyzed by analysis of variance and subjects were grouped by cognitive status and gender.

RESULTS

Sociodemographic variables did not differ among the three groups (AD, MCI and HC), except for females' age, which was therefore used as covariate in a general linear multivariate model. MNA score was significantly lower in AD patients than in HC; MCI subjects achieved intermediate scores. AD patients (both sexes) had significantly (p<0.05) higher height-normalized impedance values and lower phase angles (body cell mass) compared with HC; a higher ratio of impedance to height was found in men with MCI with respect to HC. With BIVA method, MCI subjects showed a significant displacement on the RXc graph on the right side indicating lower soft tissues (Hotelling's T2 test: men = 10.6; women = 7.9;p < 0,05) just like AD patients (Hotelling's T2 test: men = 18.2; women = 16.9; p<0,001).

CONCLUSION

Bioelectrical parameters significantly differ from MCI and AD to HC; MCI showed an intermediate pattern between AD and HC. Longitudinal studies are required to investigate if BIVA could reflect early AD-changes in body composition in subjects with MCI.

The Effect of Statins on Rate of Cognitive Decline in Mild Cognitive Impairment

Introduction

This study's aims are to identify whether a relationship between statin use and rate of cognitive decline exists. The relationship between statins and mild cognitive impairment (MCI) has been investigated in the past with the evidence showing mixed results.

Methods

Seven hundred sixty-eight subjects were identified with MCI. Subjects were stratified into six possible groups according to apolipoprotein E (APOE) ε4 allele status and statin use and assessed for decline in cognitive function.

Results

All cognitive assessments trended toward less decline with statin use. Alzheimer’s Disease Assessment Scale 11 (ADAS 11) showed the biggest difference in mean change between statin users and nonusers (−0.82 vs. −1.22, respectively). Change reached marginal significance on the ADAS 11 when stratified by APOE ε4–negative subjects.

Discussion

All cognitive assessments trended toward less decline when subjects were concurrently treated with a statin, supporting the position that statins do not have a net negative effect on cognitive assessment and suggesting a potential treatment benefit.

Quantitative EEG (QEEG) Measures Differentiate Parkinson's Disease (PD) Patients from Healthy Controls (HC)

Objectives: To find out which Quantitative EEG (QEEG) parameters could best distinguish patients with Parkinson's disease (PD) with and without Mild Cognitive Impairment from healthy individuals and to find an optimal method for feature selection.

Background: Certain QEEG parameters have been seen to be associated with dementia in Parkinson's and Alzheimer's disease. Studies have also shown some parameters to be dependent on the stage of the disease. We wanted to investigate the differences in high-resolution QEEG measures between groups of PD patients and healthy individuals, and come up with a small subset of features that could accurately distinguish between the two groups.

Methods: High-resolution 256-channel EEG were recorded in 50 PD patients (age 68.8 ± 7.0 year; female/male 17/33) and 41 healthy controls (age 71.1 ± 7.7 year; female/male 20/22). Data was processed to calculate the relative power in alpha, theta, delta, beta frequency bands across the different regions of the brain. Median, peak frequencies were also obtained and alpha1/theta ratios were calculated. Machine learning methods were applied to the data and compared. Additionally, penalized Logistic regression using LASSO was applied to the data in R and a subset of best-performing features was obtained.

Results: Random Forest and LASSO were found to be optimal methods for feature selection. A group of six measures selected by LASSO was seen to have the most effect in differentiating healthy individuals from PD patients. The most important variables were the theta power in temporal left region and the alpha1/theta ratio in the central left region.

Conclusion: The penalized regression method applied was helpful in selecting a small group of features from a dataset that had high multicollinearity.

Multistage Grading of Amnestic Mild Cognitive Impairment: The Associated Brain Gray Matter Volume and Cognitive Behavior Characterization

Background and Purpose: It is well known that there is a wide range of different pathological stages related to Alzheimer's disease (AD) among patients with amnestic mild cognitive impairment (aMCI). Further refinement of the stages based on neuropsychological and neuroimaging methods is important for earlier disease detection, as well as for the development and evaluation of disease-modifying interventions.

Materials and Methods: In this cross-sectional study, 125 aMCI patients were classified into declined progressively three stages of mild, moderate and severe, utilizing the extreme groups approach (EGA) based on their memory function. Fifty-two patients, in addition to 24 cognitively normal subjects, were included in further structural MRI analyses. Characteristics of cognitive functions and brain structures across these newly defined stages were explored through general linear models.

Results: Almost all the non-memory cognitive functions showed progressive decline as memory function deteriorated. In addition, medial structures including the right hippocampus, right lingual and left fusiform gyrus, presented with greater gray matter (GM) atrophy during the later stages of aMCI (corrected p < 0.05). Correlations were found between GM volume of the lingual gyrus and processing speed (r = 0.419, p = 0.003) and between the fusiform gyrus and general cognitive function (r = 0.281, p = 0.046). Moreover, both cognitive function and GM volume presented non-linear trajectories over stages of aMCI.

Conclusion: Our study characterized the cognitive profiles along with the degree of episodic memory impairment, and these three stages of aMCI showed non-linear progressive decline in cognitive functions and GM volumes.

Bibliometric analysis of papers on mild cognitive impairment nursing in China

Purpose

To supply further references by analyzing the status of research on mild cognitive impairment nursing in China.

Methods

Papers on mild cognitive impairment nursing published between 2005 and 2014 were collected from China National Knowledge Infrastructure, Wanfang Data, and China Biological Medicine database, while their publication dates, journals, and types were subjected to a bibliometric analysis using NoteExpress and Excel.

Results

A total of 68 papers were collected from the selected databases. The number of papers on mild cognitive impairment nursing increased annually. The selected papers were published in 44 journals, 55.88% of them were published in core journals, 35.29% received funding support, 35.29% were published by hospitals affiliated to colleges, 47.06% were published by other local hospitals, author collaboration is 2.66, and 66.18% showed co-authorship. These papers covered a wide range of topics, but were only conducted based on clinical interventions. Around 29.41% of these papers had a citation frequency of over 5, the highest citation frequency was 29, and the highest h-index was 23.

Conclusion

Beijing and Shanghai established core author groups for mild cognitive impairment nursing research. These studies should focus on the community and psychological nursing of such impairment. Targeted nursing interventions on different types of mild cognitive impairment should be adopted, new avenues for research should be opened, and various research methods should be introduced.

Neuropsychiatric Symptoms in Patients with the Main Etiological Types of Mild Neurocognitive Disorders: A Hospital-Based Case-Control Study

BACKGROUND

The diagnostic construct of mild neurocognitive disorders (MNCDs) is substantially congruent with previously proposed criteria for mild cognitive impairment (MCI). MNCD/MCI is associated with neuropsychiatric symptoms (NPS). Previous studies have examined the prevalence of NPS in amnestic and non-amnestic MCI subtypes; however, no studies exist for etiological types of MNCD. We aimed to estimate the prevalence of NPS in patients with MNCD due to Alzheimer's disease (MNCD-AD) and subcortical vascular MNCD (ScVMNCD) and to determine whether NPS would expand these MNCD phenotypes.

METHODS

The sample comprised 70 patients with MNCD-AD, 70 patients with ScVMNCD, and 55 cognitively normal elderly persons (CNEP). The diagnosis of MNCD-AD was made according to DSM-5 criteria for possible MNCD-AD. ScVMNCD patients fulfilled the DSM-5 criteria of the probable vascular MNCD and the diagnostic criteria for subcortical vascular MCI according to Frisoni et al. (1). The prevalence of NPS was based on the neuropsychiatric inventory. The statistical analyses included parametric and non-parametric tests, multivariate regression, and Spearman's correlation coefficient.

RESULTS

About 69.1% of CNEP, 97.1% of MNCD-AD, and 100% of ScVMNCD patients had one or more NPS. The prevalence of NPS in both MNCD groups was significantly higher than that in CNEP. The most prevalent NPS that had significant differential diagnostic value in separating MNCD-AD from ScVMNCD, as well as MNCD from CNEP, were anxiety (81.43%) and irritability (67.14%) in MNCD-AD and depression (81.43%) in ScVMNCD. In both MNCD groups, we observed significant (p < 0.05) correlations between all distinguishing NPS and the differential cognitive disturbances: the amnestic syndrome in MNCD-AD and executive dysfunction in ScVMNCD.

CONCLUSION

NPS occur in the majority of persons with MNCD-AD and ScVMNCD. Anxiety and irritability are the most prevalent NPS in MNCD-AD, as well as depression in ScVMNCD. The amnestic-anxious-irritable syndrome can be the main phenotype in MNCD-AD, on the other hand, the dysexecutive-depressive syndrome can be considered as the most prevalent clinical manifestation in ScVMNCD. Obtained data may be used for clinical differentiation of MNCD-AD and ScVMNCD patients.

From mild cognitive impairment to subjective cognitive decline: conceptual and methodological evolution

Identification of subjects at the early stages of Alzheimer's disease (AD) is fundamental for drug development and possible intervention or prevention of cognitive decline. The concept of mild cognitive impairment (MCI) evolved during the past two decades to define subjects at the transitional stage between normal aging and dementia. Evidence from cross-sectional and longitudinal studies has shown that MCI is associated with an increased risk of positive AD biomarkers and an increased annual conversion rate of 5%-17% to AD. The presence of AD biomarkers in subjects with MCI was associated with an even higher risk of progression to dementia. However, earlier clinical trials for pharmacotherapy in subjects with MCI were disappointing. To extend the spectrum of AD to an earlier stage before MCI, subjective cognitive decline (SCD) was introduced and was defined as self-reported cognitive decline before the deficits could be detected by cognitive tests. Subjects with SCD have an increased risk of underlying AD pathology. However, SCD can also develop secondary to other heterogeneous etiologies, including other neurodegenerative and psychiatric diseases, personality traits, physical conditions, and medication use. Several clinical and biomarker features were proposed to predict risk of conversion to AD in subjects with SCD. Further longitudinal studies are needed to support the validity of these high-risk features.

Mild Cognitive Impairments Moderate the Effect of Time on Verbal Fluency Performance

OBJECTIVES

Mild cognitive impairments (MCI) is a transitional state in aging associated with increased risk of incident dementia. The current study investigated whether MCI status moderated the effect of time on word generation during verbal fluency tasks. Specifically, the objective was to determine whether MCI status had differential effects on initial automatic or latter more effortful retrieval processes of fluency tasks.

METHODS

Participants were community residing older adults enrolled in a longitudinal cohort study. Of the 408 participants, 353 were normal (age=76.06±6.61; %female=57.8) and 55 were diagnosed with MCI (age=78.62±7.00; %female=52.7). Phonemic and category fluency were each administered for 60 s, but performance was recorded at three consecutive 20-s intervals (0-20 s [T1], 21-40 s [T2], 41-60 s [T3]. Separate linear mixed effects models for each fluency task were used to determine the effects of group, time, and their interaction on word generation.

RESULTS

In both fluency tasks, word generation declined as a function of time. Individuals with MCI generated fewer words compared to controls during the first 20 s of phonemic (beta=-1.56; p<.001; d=0.28) and category fluency (beta=-1.85; p<.001; d=0.37). Group by time interactions revealed that individuals with MCI demonstrated attenuated declines in word generation from the first to the second and third time intervals of both phonemic ([T1 vs. T2] beta=2.17, p=.001; d=0.41; [T1 vs. T3]beta=2.28, p=.001; d=0.45) and category ([T1 vs. T2] beta= 2.22, p=.002; d=0.50; [T1 vs. T3]beta=3.16, p<.001; d=0.71) fluency.

CONCLUSIONS

Early automatic retrieval processes in verbal fluency tasks are compromised in MCI. (JINS, 2017, 23, 44-55).

Modulatory effects of acupuncture on brain networks in mild cognitive impairment patients

Functional magnetic resonance imaging has been widely used to investigate the effects of acupuncture on neural activity. However, most functional magnetic resonance imaging studies have focused on acute changes in brain activation induced by acupuncture. Thus, the time course of the therapeutic effects of acupuncture remains unclear. In this study, 32 patients with amnestic mild cognitive impairment were randomly divided into two groups, where they received either Tiaoshen Yizhi acupuncture or sham acupoint acupuncture. The needles were either twirled at Tiaoshen Yizhi acupoints, including Sishencong (EX-HN1), Yintang (EX-HN3), Neiguan (PC6), Taixi (KI3), Fenglong (ST40), and Taichong (LR3), or at related sham acupoints at a depth of approximately 15 mm, an angle of ± 60°, and a rate of approximately 120 times per minute. Acupuncture was conducted for 4 consecutive weeks, five times per week, on weekdays. Resting-state functional magnetic resonance imaging indicated that connections between cognition-related regions such as the insula, dorsolateral prefrontal cortex, hippocampus, thalamus, inferior parietal lobule, and anterior cingulate cortex increased after acupuncture at Tiaoshen Yizhi acupoints. The insula, dorsolateral prefrontal cortex, and hippocampus acted as central brain hubs. Patients in the Tiaoshen Yizhi group exhibited improved cognitive performance after acupuncture. In the sham acupoint acupuncture group, connections between brain regions were dispersed, and we found no differences in cognitive function following the treatment. These results indicate that acupuncture at Tiaoshen Yizhi acupoints can regulate brain networks by increasing connectivity between cognition-related regions, thereby improving cognitive function in patients with mild cognitive impairment.

Molecular Diagnostics of Ageing and Tackling Age-related Disease

As average life expectancy increases there is a greater focus on health-span and, in particular, how to treat or prevent chronic age-associated diseases. Therapies which were able to control 'biological age' with the aim of postponing chronic and costly diseases of old age require an entirely new approach to drug development. Molecular technologies and machine-learning methods have already yielded diagnostics that help guide cancer treatment and cardiovascular procedures. Discovery of valid and clinically informative diagnostics of human biological age (combined with disease-specific biomarkers) has the potential to alter current drug-discovery strategies, aid clinical trial recruitment and maximize healthy ageing. I will review some basic principles that govern the development of 'ageing' diagnostics, how such assays could be used during the drug-discovery or development process. Important logistical and statistical considerations are illustrated by reviewing recent biomarker activity in the field of Alzheimer's disease, as dementia represents the most pressing of priorities for the pharmaceutical industry, as well as the chronic disease in humans most associated with age.

Approaches in methodology for population-based longitudinal study on neuroprotective model for healthy longevity (TUA) among Malaysian Older Adults

A number of longitudinal studies on aging have been designed to determine the predictors of healthy longevity, including the neuroprotective factors, however, relatively few studies included a wide range of factors and highlighted the challenges faced during data collection. Thus, the longitudinal study on neuroprotective model for healthy longevity (LRGS TUA) has been designed to prospectively investigate the magnitude of cognitive decline and its risk factors through a comprehensive multidimensional assessment comprising of biophysical health, auditory and visual function, nutrition and dietary pattern and psychosocial aspects. At baseline, subjects were interviewed for their status on sociodemographic, health, neuropsychological test, psychosocial and dietary intake. Subjects were also measured for anthropometric and physical function and fitness. Biospecimens including blood, buccal swap, hair and toenail were collected, processed and stored. A subsample was assessed for sensory function, i.e., vision and auditory. During follow-up, at 18 and 36 months, most of the measurements, along with morbidity and mortality outcomes will be collected. The description of mild cognitive impairment, successful aging and usual aging process is presented here. A total 2322 respondents were recruited in the data analysis at baseline. Most of the respondents were categorized as experiencing usual aging (73 %), followed by successful aging (11 %) and mild cognitive impairment (16 %). The LRGS TUA study is the most comprehensive longitudinal study on aging in Malaysia, and will contribute to the understanding of the aging process and factors associated with healthy aging and mental well-being of a multiethnic population in Malaysia.

Using Cognitive Screening Tests in Audiology

PURPOSE

The population of the United States is aging. Those older adults are living longer than ever and have an increased desire for social participation. As a result, audiologists are likely to see an increased demand for service by older clients whose communication difficulty is caused by a combination of hearing loss and cognitive impairment. For these individuals, early detection of mild cognitive impairment is critical for providing timely medical intervention and social support.

METHOD

This tutorial provides information about cognition of older adults, mild cognitive impairment, and cognitive screening tests, with the purpose of assisting audiologists in identifying and appropriately referring potential cases of cognitive impairment.

RESULTS

Topics addressed also include how to administer cognitive screening tests on individuals with hearing loss, how to use test results in audiology practice, and the potential of using cognitive screening tests for evaluating the benefit of clinical interventions.

CONCLUSIONS

As health care professionals who serve the aging population, audiologists are likely to encounter cases of undiagnosed cognitive impairment. In order to provide timely referral for medical assistance as well as an optimized individual outcome of audiologic interventions, audiologists should be trained to recognize an abnormality in older clients' cognitive status.

18F-Labeled Benzyldiamine Derivatives as Novel Flexible Probes for Positron Emission Tomography of Cerebral β-Amyloid Plaques

Early noninvasive visualization of cerebral β-amyloid (Aβ) plaques with positron emission tomography (PET) is the most feasible way to diagnose Alzheimer's disease (AD). In this study, a series of flexible benzyldiamine derivatives (BDA) were proposed for binding to aggregated β-amyloid 1-42 (Aβ_1-42) with high adaptability, high binding affinity (6.8 ± 0.6 nM), and rapid body excretion. The methylthio (12) and ethoxyl (10) derivatives were further labeled with ¹⁸F directly on their benzene ring and examined as PET probes for Aβ plaque imaging. [¹⁸F]12 displayed 4.87 ± 0.52% ID/g initial uptake and prompt washout from normal brain in biodistribution studies. MicroPET-CT imaging indicated sufficient retention of [¹⁸F]12 but lower white matter uptake in the brain of an AD transgenic mouse model compared with that of commercial [¹⁸F]AV-45. Our experimental results provide new insights for developing targeting ligands possessing a flexible framework for use as efficient Aβ probes for PET imaging of AD brain.

Mortality in Mild Cognitive Impairment Diagnosed with DSM-5 Criteria and with Petersen's Criteria: A 17-Year Follow-Up in a Community Study

OBJECTIVE

To explore the possibility that the mortality risk of mild cognitive impairment (MCI) as diagnosed using Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria (DSM-5-MCI) will be higher than using Petersen's criteria (P-MCI) and to report the population-attributable fraction (PAF) of mortality due to MCI.

METHODS

A representative community sample of 4,803 individuals aged 55 or more years was interviewed and then followed for 17 years. Standardized instruments were used in the assessment, including the Geriatric Mental State-AGECAT, and research psychiatrists diagnosed P-MCI and DSM-5-MCI cases following operationalized criteria. Mortality information was obtained from the official population registry. Kaplan-Meier age-adjusted survival curves were built for the MCI diagnostic groups, and Cox proportional hazards regression models were used to calculate the hazard ratio of death in participants with MCI relative to those without. We also estimated the PAF of mortality due to specific MCI diagnostic groups.

RESULTS

Compared with noncases, the mortality rate ratio was approximately double in DSM-5-MCI individuals (2.3) than in P-MCI individuals (1.2). In the multivariate statistical analysis, a significant association between each diagnostic category and mortality was observed but was only maintained in the final model in DSM-5-MCI cases (hazard ratio: 1.24). The PAF of mortality due to MCI was approximately 1% in both MCI categories.

CONCLUSION

The mortality risk in comparison with noncases was higher in DSM-5-MCI than in P-MCI. The PAF of mortality in DSM-5-MCI individuals was ~ 1% over a 17-year period.

Prognostic Significance of Mild Cognitive Impairment Subtypes for Dementia and Mortality: Data from the NEDICES Cohort

BACKGROUND

The predictive value of diverse subtypes of mild cognitive impairment (MCI) for dementia and death is highly variable.

OBJECTIVE

To compare the predictive value of several MCI subtypes in progression to dementia and/or mortality in the NEDICES (Neurological Disorders in Central Spain) elderly cohort.

METHODS

Retrospect algorithmic MCI subgroups were established in a non-dementia baseline NEDICES cohort using Spanish adaptations of the original Mini-Mental State Examination (MMSE-37) and Pfeffer's Functional Activities Questionnaire (Pfeffer-11). The presence of MCI was defined according two cognitive criteria: using two cut-offs points on the total MMSE-37 score. Five cognitive domains were used to establish the MCI subtypes. Functional capacity (Pfeffer-11) was preserved or minimally impaired in all MCI participants. The incident dementia diagnoses were established by specialists and the mortality data obtained from Spanish official registries.

RESULTS

3,411 participants without dementia were assessed in 1994-5. The baseline prevalence of MCI varied according to the MCI definition (4.3%-31.8%). The follow-up was a mean of 3.2 years (1997-8). The dementia incidence varied between 14.9 and 71.8 per 1,000/person-years. The dementia conversion rate was increased in almost all MCI subgroups (p >  0.01), and mortality rate was raised only in four MCI subtypes. The amnestic-multi-domain MCI (aMd-MCI) had the best dementia predictive accuracy (highest positive likelihood ratio and highest clinical utility when negative).

CONCLUSIONS

Those with aMd-MCI were at greatest risk of progression to dementia, as in other surveys and might be explored with increased attention in MCI research and in dementia preventive trials.

Evolving methods to combine cognitive and physical training for individuals with mild cognitive impairment: study protocol for a randomized controlled study

BACKGROUND

Nonpharmacologic interventions, such as cognitive training or physical exercise, are effective in improving cognitive functions for older adults with mild cognitive impairment (MCI). Some researchers have proposed that combining physical exercise with cognitive training may augment the benefits of cognition. However, strong evidence is lacking regarding whether a combined therapy is superior to a single type of training for older adults with MCI. Moreover, which combination approach - combining physical exercise with cognitive training sequentially or simultaneously - is more advantageous for cognitive improvement is not yet clear. This proposed study is designed to clarify these questions.

METHODS/DESIGN

This study is a single-blinded, multicenter, randomized controlled trial. Eighty individuals with MCI will be recruited and randomly assigned to cognitive training (COG), physical exercise training (PE), sequential training (SEQ), and dual-task training (DUAL) groups. The intervention programs will be 90 min/day, 2-3 days/week, for a total of 36 training sessions. The participants in the SEQ group will first perform 45 min of physical exercise followed by 45 min of cognitive training, whereas those in the DUAL group will perform physical exercise and cognitive training simultaneously. Participants will be assessed at baseline, after the intervention, and at 6-month follow-up. The primary cognitive outcome tests will include the Montreal Cognitive Assessment and the color-naming Stroop test. Other outcomes will include assessments that evaluate the cognitive, physical, and daily functions of older adults with MCI.

DISCUSSION

The results of this proposed study will provide important information regarding the feasibility and intervention effects of combining physical exercise and cognitive training for older individuals with MCI.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02512627 , registered on 20 July 2015.

Predictive Factors for Verbal Memory Performance Over Decades of Aging: Data from the Women's Healthy Ageing Project

BACKGROUND

Abnormalities in brain structure and function can occur several decades prior to the onset of cognitive decline. It is in the preceding decades that an intervention is most likely to be effective, when informed by an understanding of factors contributing to the disease prodrome. Few studies, however, have sufficient longitudinal data on relevant risks to determine the optimum targets for interventions to improve cognition in aging. In this article we examine the timing and exposure of factors contributing to verbal memory performance in later life.

METHODS

387 participants from the population-based Women's Healthy Ageing Project, mean age at baseline of 49.6 years (range: 45-55 years), had complete neuropsychiatric assessments, clinical information, physical measures, and biomarkers collected at baseline, with at least three follow-up visits that included at least one cognitive reassessment. Mixed linear models were conducted to assess the significance of risk factors on later-life verbal memory. We explored the influence of early, contemporaneous, and cumulative exposures.

RESULTS

Younger age and better education were associated with baseline memory test performance (CERAD). Over the 20 years of study follow-up, cumulative mid- to late-life physical activity had the strongest effect on better later life verbal memory (0.136 [0.058, 0.214]). The next most likely contributors to verbal memory in late life were the negative effect of cumulative hypertension (-0.033 [-0.047, -0.0.18] and the beneficial effect of HDL cholesterol (0.818 [0.042, 1.593]).

CONCLUSIONS

Findings suggest that midlife interventions focused on physical activity, hypertension control, and achieving optimal levels of HDL cholesterol will help maintain later-life verbal memory skills.

Lithium activates brain phospholipase A2 and improves memory in rats: implications for Alzheimer's disease

Phospholipase A2 (Pla2) is required for memory retrieval, and its inhibition in the hippocampus has been reported to impair memory acquisition in rats. Moreover, cognitive decline and memory deficits showed to be reduced in animal models after lithium treatment, prompting us to evaluate possible links between Pla2, lithium and memory. Here, we evaluated the possible modulation of Pla2 activity by a long-term treatment of rats with low doses of lithium and its impact in memory. Wistar rats were trained for the inhibitory avoidance task, treated with lithium for 100 days and tested for perdurability of long-term memory. Hippocampal samples were used for quantifying the expression of 19 brain-expressed Pla2 genes and for evaluating the enzymatic activity of Pla2 using group-specific radio-enzymatic assays. Our data pointed to a significant perdurability of long-term memory, which correlated with increased transcriptional and enzymatic activities of certain members of the Pla2 family (iPla2 and sPla2) after the chronic lithium treatment. Our data suggest new possible targets of lithium, add more information on its pharmacological activity and reinforce the possible use of low doses of lithium for the treatment of neurodegenerative conditions such as the Alzheimer's disease.

Falls and Fall Prevention in Older Adults With Early-Stage Dementia: An Integrative Review

Older adults with mild cognitive impairment (MCI) and early-stage dementia have an increased risk of falling, with risks to their health and quality of life. The purpose of the current integrative review was to evaluate evidence on fall risk and fall prevention in this population. Studies were included if they examined falls or fall risk factors in older adults with MCI or early-stage dementia, or reported interventions in this population; 40 studies met criteria. Evidence supports the increased risk of falls in individuals even in the early stages of dementia or MCI, and changes in gait, balance, and fear of falling that may be related to this increased fall risk. Interventions included exercise and multifactorial interventions that demonstrated some potential to reduce falls in this population. Few studies had strong designs to provide evidence for recommendations. Further study in this area is warranted. [Res Gerontol Nurs. 2017; 10(03):139-148.].

Effects of Intranasal Oxytocin on Long-Term Memory in Healthy Humans: A Systematic Review

Preclinical Research The neuropeptide oxytocin (Oxt) is implicated in complex emotional and social behaviors and appears to play an important role in learning and memory. Animal studies have shown that the effects of exogenous Oxt on memory vary according to the timing of administration, context, gender, and dose and may improve the memory of social, but not nonsocial stimuli. Oxt is intimately involved in a broad array of neuropsychiatric functions and may therefore be a pharmacological target for several psychiatric disorders. This review summarizes the potential effects of Oxt on long-term memory processes in healthy humans based on a PubMed search over the period 1980-2016. The effects of intranasal Oxt on human memory are controversial and the studies included in this review have applied a variety of learning paradigms, in turn producing variable outcomes. Specifically, data on the long-term memory of nonemotional stimuli found no effect or even worsening in memory, while studies using emotional stimuli showed an improvement of long-term memory performance. In conclusion, this review identified a link between long-term memory performance and exogenous intranasal Oxt in humans, although these results still warrant further confirmation in large, multicenter randomized controlled trials. Drug Dev Res 77 : 479-488, 2016. © 2016 Wiley Periodicals, Inc.

Critical appraisal of questionnaires to assess functional impairment in individuals with mild cognitive impairment

BACKGROUND

Mild deficits in instrumental activities of daily living (IADLs) have consistently been reported in the individuals with mild cognitive impairment (MCI). A variety of functional assessment tools, including self-and informant report questionnaires and performance-based measures, have been employed in MCI. Previously, a limited focus has been directed at appraising the quality of questionnaires. The goal of this study was to identify the questionnaires that have been validated in the MCI population. Additionally, the quality of validation studies and psychometric attributes of these questionnaires were appraised.

METHODS

Relevant articles were systematically searched in PsychINFO, Ovid MEDLINE, and CINAHL against specific eligibility criteria. To evaluate the methodology of the psychometric studies, the COSMIN checklist was employed. Also, the psychometric properties of the assessment tools were evaluated based upon Terwee's criteria.

RESULTS

A total of five psychometric studies and questionnaires were critically evaluated. Varying psychometric properties were available for the chosen tools. None of the studies received the best possible rating for their methodological quality. It was found that questionnaires with high discriminative ability to distinguish MCI from other diagnostic groups were: Disability Assessment in Dementia-6 (DAD-6), Functional Activity Questionnaire (FAQ), and Alzheimer's Disease Cooperative Study/Activities of Daily Living scale adapted for MCI patients (ADCS-MCI-ADL-24).

CONCLUSION

Psychometric studies with strong methodological rigor are required in the future. Considering the fact that IADL decline has been associated with dementia, early detection of functional difficulties in MCI needs to be encouraged as it will allow suitable and timely interventions to prolong functional independence of affected individuals.

Mild cognitive impairment in a Spanish representative sample: prevalence and associated factors

OBJECTIVE

Given the limitations of treatments for dementia, the characterisation of the early stages of dementia is crucial for the development of preventive programmes and interventions. We aimed to estimate the prevalence of mild cognitive impairment (MCI) and examine its medical and lifestyle correlates in a nationally representative sample of the Spanish population.

METHODS

A total of 3625 participants (≥50 years of age) were interviewed in a cross-sectional study. MCI was defined as the presence of cognitive concerns, the objective evidence of impairment in one or more cognitive domains, the preservation of independence in functional abilities and no dementia. Participants were also asked to provide sociodemographic, health status and lifestyle information. Logistic regression analyses were performed using the overall sample and by age groups.

RESULTS

The overall prevalence of MCI was 9.6%, with higher rates in older people and women. In the overall model, after adjustment for potential confounders, depression [odds ratio (OR) = 1.79; 95% confidence interval (CI) = 1.21, 2.66], diabetes (OR = 1.43; 95% CI = 1.05, 1.95), sleep disturbances (OR = 1.66; 95% CI = 1.09, 2.55) and low level of physical activity (OR = 1.71; 95% CI = 1.26, 2.31) were associated with significantly higher odds for MCI. When stratified by age groups, depression (OR = 2.41; 95% CI = 1.35, 4.31), stroke (OR = 3.77; 95% CI = 1.44, 9.83) and obesity (OR = 2.06; 95% CI = 1.20, 3.53) were significantly associated with MCI in middle-aged participants (50-64 years), whereas low level of physical activity (OR = 1.85; 95% CI = 1.32, 2.59) and sleep disturbances (OR = 1.79; 95% CI = 1.05, 3.05) were associated with MCI in individuals aged 65+ years.

CONCLUSIONS

Significant associations between MCI and psychological, cardiovascular and lifestyle factors were found. Targeting modifiable risk factors might reduce the risk for MCI and subsequent dementia.

Depressive symptoms increase the risk of progression to dementia in subjects with mild cognitive impairment: systematic review and meta-analysis

OBJECTIVE

There is a long-standing debate in the literature whether depressive symptoms increase the risk of dementia in older with mild cognitive impairment (MCI). We aim to conduct a meta-analysis of studies that evaluated the risk of dementia in subjects with MCI and depressive symptoms compared with subjects with MCI and no depressive symptoms.

METHODS

We calculated the relative risk of progression to dementia in subjects with MCI and depressive symptoms compared with subjects with MCI and no depressive symptoms using a generic inverse variance method with random effect models.

RESULTS

Eighteen studies were included in the meta-analysis, with a sample size of 10,861 MCI subjects. The pooled relative risk of progressing to dementia was 1.28 CI95% [1.09-1.52] (p = 0.003) in the group of MCI subjects with depressive symptoms compared with the MCI subjects with no depressive symptoms.

DISCUSSION

Our results provide additional evidence that depressive symptoms determine an additive risk effect to the progression to dementia in subjects with MCI. The comorbidity between depression and cognitive impairment can be an intervention target for prevention of dementia in MCI subjects. Copyright © 2015 John Wiley & Sons, Ltd.

Functional Disability in Mild Cognitive Impairment: A Systematic Review and Meta-Analysis

Accumulating evidence suggests that the pre-dementia syndrome mild cognitive impairment (MCI) is characterized by decrements in instrumental activities of daily living (IADL). The current review was a quantitative synthesis of the available literature to objectively characterize IADL disability in MCI while clarifying inconsistencies in findings across studies. It was hypothesized that individuals with MCI would display significantly greater functional impairment relative to cognitively intact controls. Candidate moderators specified a priori included functional assessment approach, MCI subtype, depressive symptoms, and language conducted. Online databases (PubMed/MEDLINE and PsycINFO) and reference lists were searched to identify peer-reviewed publications assessing IADL in MCI compared to normal aging. A total of 151 effect sizes derived from 106 studies met inclusionary criteria (N = 62,260). Random effects models yielded a large overall summary effect size (Hedges' g = 0.76, 95 % confidence interval: 0.68 - 0.83, p < .001) confirmed in multi-level analyses adjusted for nesting of effect sizes within studies (g = 0.78, 95 % confidence interval: 0.69 - 0.87). Functional assessment strategy and MCI subtype were significant moderators of effect size, whereas depressive symptoms and language were not. Results convincingly demonstrate that MCI is associated with significant difficulties in the performance of complex everyday tasks. It appears that functional decline, like cognitive decline, exists on a continuum from healthy aging to dementia onset. Implications for clinical practice and research priorities are discussed.

Does Caffeine Consumption Modify Cerebrospinal Fluid Amyloid-β Levels in Patients with Alzheimer's Disease?

Caffeine may be protective against Alzheimer's disease (AD) by modulating amyloid-β (Aβ) metabolic pathways. The present work aimed to study a possible association of caffeine consumption with the cerebrospinal fluid (CSF) biomarkers, particularly Aβ. The study included 88 patients with AD or mild cognitive impairment. The consumption of caffeine and theobromine was evaluated using a validated food questionnaire. Quantification of caffeine and main active metabolites was performed with liquid chromatography coupled to tandem mass spectrometry. The levels of A(1-42), total tau, and phosphorylated tau in the CSF were determined using sandwich ELISA methods and other Aβ species, Aβ(X-38), Aβ(X-40), and Aβ(X-42), with the MSD Aβ Triplex assay. The concentration of caffeine was 0.79±1.15 μg/mL in the CSF and 1.20±1.88 μg/mL in the plasma. No correlation was found between caffeine consumption and Aβ42 in the CSF. However, a significant positive correlation was found between the concentrations of theobromine, both in the CSF and in the plasma, with Aβ42 in the CSF. Theobromine in the CSF was positively correlated with the levels of other xanthines in the CSF, but not in the plasma, suggesting that it may be formed by central metabolic pathways. In conclusion, caffeine consumption does not modify the levels of CSF biomarkers, and does not require to be controlled for when measuring CSF biomarkers in a clinical setting. Since theobromine is associated with a favorable Aβ profile in the CSF, the possibility that it might have a protective role in AD should be further investigated.

Altered Neural Activity during Semantic Object Memory Retrieval in Amnestic Mild Cognitive Impairment as Measured by Event-Related Potentials

Deficits in semantic memory in individuals with amnestic mild cognitive impairment (aMCI) have been previously reported, but the underlying neurobiological mechanisms remain to be clarified. We examined event-related potentials (ERPs) associated with semantic memory retrieval in 16 individuals with aMCI as compared to 17 normal controls using the Semantic Object Retrieval Task (EEG SORT). In this task, subjects judged whether pairs of words (object features) elicited retrieval of an object (retrieval trials) or not (non-retrieval trials). Behavioral findings revealed that aMCI subjects had lower accuracy scores and marginally longer reaction time compared to controls. We used a multivariate analytical technique (STAT-PCA) to investigate similarities and differences in ERPs between aMCI and control groups. STAT-PCA revealed a left fronto-temporal component starting at around 750 ms post-stimulus in both groups. However, unlike controls, aMCI subjects showed an increase in the frontal-parietal scalp potential that distinguished retrieval from non-retrieval trials between 950 and 1050 ms post-stimulus negatively correlated with the performance on the logical memory subtest of the Wechsler Memory Scale-III. Thus, individuals with aMCI were not only impaired in their behavioral performance on SORT relative to controls, but also displayed alteration in the corresponding ERPs. The altered neural activity in aMCI compared to controls suggests a more sustained and effortful search during object memory retrieval, which may be a potential marker indicating disease processes at the pre-dementia stage.

Case Finding of Mild Cognitive Impairment and Dementia and Subsequent Care; Results of a Cluster RCT in Primary Care

PURPOSE

Despite a call for earlier diagnosis of dementia, the diagnostic yield of case finding and its impact on the mental health of patients and relatives are unclear. This study assessed the effect of a two-component intervention of case finding and subsequent care on these outcomes.

METHODS

In a cluster RCT we assessed whether education of family physicians (FPs; trial stage 1) resulted in more mild cognitive impairment (MCI) and dementia diagnoses among older persons in whom FPs suspected cognitive decline and whether case finding by a practice nurse and the FP (trial stage 2) added to this number of diagnoses. In addition, we assessed mental health effects of case finding and subsequent care (trial stage 2). FPs of 15 primary care practices (PCPs = clusters) judged the cognitive status of all persons ≥ 65 years. The primary outcome, new MCI and dementia diagnoses by FPs after 12 months as indicated on a list, was assessed among all persons in whom FPs suspected cognitive impairment but without a formal diagnosis of dementia. The secondary outcome, mental health of patients and their relatives, was assessed among persons consenting to participate in trial stage 2. Trial stage 1 consisted of either intervention component 1: training FPs to diagnose MCI and dementia, or control: no training. Trial stage 2 consisted of either intervention component 2: case finding of MCI and dementia and care by a trained nurse and the FP, or control: care as usual.

RESULTS

Seven PCPs were randomized to the intervention; eight to the control condition. MCI or dementia was diagnosed in 42.3% (138/326) of persons in the intervention, and in 30.5% (98/321) in the control group (estimated difference GEE: 10.8%, OR: 1.51, 95%-CI 0.60-3.76). Among patients and relatives who consented to stage 2 of the trial (n = 145; 25%), there were no differences in mental health between the intervention and control group.

CONCLUSIONS

We found a non-significant increase in the number of new MCI diagnoses. As we cannot exclude a clinically relevant effect, a larger study is warranted to replicate ours.

TRIAL REGISTRATION

Nederlands Trial Register NTR3389.

Development of TUA-WELLNESS screening tool for screening risk of mild cognitive impairment among community-dwelling older adults

Background and aim

Focus on screening for cognitive impairment has to be given particular importance because of the rising older adult population. Thus, this study aimed to develop and assess a brief screening tool consisting of ten items that can be self-administered by community dwelling older adults (TUA-WELLNESS).

Methodology

A total of 1,993 noninstitutionalized respondents aged 60 years and above were selected for this study. The dependent variable was mild cognitive impairment (MCI) assessed using neuropsychological test batteries. The items for the screening tool comprised a wide range of factors that were chosen mainly from the analysis of ordinal logistic regression (OLR) and based on past literature. A suitable cut-off point was developed using receiver operating characteristic analysis.

Results

A total of ten items were included in the screening tool. From the ten items, eight were found to be significant by ordinal logistic regression and the remaining two items were part of the tool because they showed strong association with cognitive impairment in previous studies. The area under curve (AUC), sensitivity, and specificity for cut-off 11 were 0.84%, 83.3%, and 73.4%, respectively.

Conclusion

TUA-WELLNESS screening tool has been used to screen for major risk factors of MCI among Malaysian older adults. This tool is only suitable for basic MCI risk screening purpose and should not be used for diagnostic purpose.

Endocrine Risk Factors for Cognitive Impairment

Cognitive impairment, including Alzheimer's disease and other kinds of dementia, is a major health problem in older adults worldwide. Although numerous investigators have attempted to develop effective treatment modalities or drugs, there is no reasonably efficacious strategy for preventing or recovering from cognitive impairment. Therefore, modifiable risk factors for cognitive impairment have received attention, and the growing literature of metabolic risk factors for cognitive impairment has expanded from epidemiology to molecular pathogenesis and therapeutic management. This review focuses on the epidemiological evidence for the association between cognitive impairment and several endocrine risk factors, including insulin resistance, dyslipidemia, thyroid dysfunction, vitamin D deficiency, and subclinical atherosclerosis. Researches suggesting possible mechanisms for this association are reviewed. The research investigating modifiable endocrine risk factors for cognitive impairment provides clues for understanding the pathogenesis of cognitive impairment and developing novel treatment modalities. However, so far, interventional studies investigating the beneficial effect of the "modification" of these "modifiable risk factors" on cognitive impairment have reported variable results. Therefore, well-designed, randomized prospective interventional studies are needed.

Proton magnetic resonance spectroscopy as a diagnostic biomarker in mild cognitive impairment following stroke in acute phase

To investigate proton magnetic resonance spectroscopy (HMRS) as a diagnostic biomarker to identify mild cognitive impairment (MCI) following stroke in the acute phase. A total of 72 stroke patients were recruited in the acute phase of stroke from the Department of Neurology, including 36 stroke patients with MCI and 36 stroke patients without MCI. All patients underwent brain MRI/MRS examination on a 3.0 T scanner and a neuropsychological test in the acute phase of stroke. Single-voxel HMRS was performed to obtain hippocampal metabolism intensities and brain infarcts were assessed on MRI. Group difference in metabolite ratios was analyzed using a T-test. Spearman rank correlation was used to study the correlation between metabolite ratios and Montreal Cognitive Assessment scores. The hippocampal n-acetylaspartate/creatine (NAA/Cr) ratio was found to be significantly lower in stroke patients with MCI compared with stroke patients without MCI (P<0.02). However, we found no differences in the metabolite ratios between hippocampus ipsilateral to infarctions and the contralateral side (P>0.05) in stroke patients with MCI. Furthermore, a correlation was found between hippocampal NAA/Cr ratios and Montreal Cognitive Assessment scores in stroke patients with MCI (P<0.01). HMRS could be a biomarker to identify MCI following stroke in the acute phase by capturing neurodegenerative changes.

Effects of alternative interventions among hospitalized, cognitively impaired older adults

AIM

Compare within site effects of three interventions designed to enhance outcomes of hospitalized cognitively impaired elders.

METHODS

Prospective, nonrandomized, confirmatory phased study. In Phase I, 183 patients received one of three interventions: augmented standard care (ASC), resource nurse care (RNC) or Transitional Care Model (TCM). In Phase II, 205 patients received the TCM.

RESULTS

Time to first rehospitalization or death was longer for the TCM versus ASC group (p = 0.017). Rates for total all-cause rehospitalizations and days were significantly reduced in the TCM versus ASC group (p < 0.001, both). No differences were observed between RNC versus TCM.

CONCLUSION

Findings suggest the TCM is more effective than ASC. However, potential effects of the RNC relative to the TCM warrant further study.

The validity of the Memory Alteration Test and the Test Your Memory test for community-based identification of amnestic mild cognitive impairment

Introduction

This study investigated the validity of two brief cognitive tests (Memory Alteration Test [M@T] and Test Your Memory [TYM] test) for identifying people with aMCI in the community.

Methods

Older people were invited to participate by their general practitioner practice. Eligible participants were assessed for aMCI using an operationalized approach to the Petersen criteria and the M@T and TYM.

Results

Both tests demonstrated significant ability in discriminating between people with aMCI and controls (AUC = 0.91 for M@T and 0.80 for TYM [P < .001 for both]). M@T performed with higher sensitivity than TYM (85% vs. 63%) and similar specificity (84% vs. 87%). Both tests demonstrated moderate test-retest reliability (κ = ∼0.5) and took <10 minutes to administer.

Discussion

M@T and TYM are quick to administer. M@T demonstrated higher diagnostic test accuracy than TYM and could provide an efficient method for identifying aMCI in clinical and research settings.

Conversion to dementia in mild cognitive impairment diagnosed with DSM-5 criteria and with Petersen's criteria

OBJECTIVE

In a background of revision of criteria for states of increased risk for progression to dementia, we compare the conversion rate to dementia and Alzheimer's disease (AD) of mild cognitive impairment (MCI) as diagnosed using DSM-5 (DSM-5-MCI) and Petersen's (P-MCI) criteria.

METHOD

A population representative cohort of 4057 dementia-free individuals 55+ years of age was followed up at 2.5 and 4.5 years in Zaragoza, Spain (ZARADEMP). Using the Geriatric Mental State- AGECAT for assessment, research psychiatrists diagnosed DSM-5-MCI and P-MCI following operationalized criteria. 'Conversion rate' (CR), 'annual conversion rate' (ACR), and incidence rate (IR) were calculated along with incidence rate ratio (IRR) to compare the performance of the intermediate cognitive definitions.

RESULTS

At 4.5-year follow-up, in individuals aged 65+ years, ACRs for non-cases, P-MCI, and DSM-5-MCI were 0.8, 1.9 and 3.4, respectively, for global dementia. The IRRs were 2.9 and 5.3 for P-MCI and DSM5-MCI, respectively, being the non-cases the reference category. The corresponding values were slightly lower for AD.

CONCLUSION

Conversion rate to dementia and AD was higher using DSM-5-MCI criteria than using Petersen's criteria. However, prediction of the construct still has some way to go, as most MCI individuals did not convert at 4.5-year follow-up.

Apathy and noradrenaline: silent partners to mild cognitive impairment in Parkinson's disease?

PURPOSE OF REVIEW

Mild cognitive impairment (MCI) is a comorbid factor in Parkinson's disease. The aim of this review is to examine the recent neuroimaging findings in the search for Parkinson's disease MCI (PD-MCI) biomarkers to gain insight on whether MCI and specific cognitive deficits in Parkinson's disease implicate striatal dopamine or another system.

RECENT FINDINGS

The evidence implicates a diffuse pathophysiology in PD-MCI rather than acute dopaminergic involvement. On the one hand, performance in specific cognitive domains, notably in set-shifting and learning, appears to vary with dopaminergic status. On the other hand, motivational states in Parkinson's disease along with their behavioral and physiological indices suggest a noradrenergic contribution to cognitive deficits in Parkinson's disease. Finally, Parkinson's disease's pattern of neurodegeneration offers an avenue for continued research in nigrostriatal dopamine's role in distinct behaviors, as well as the specification of dorsal and ventral striatal functions.

SUMMARY

The search for PD-MCI biomarkers has employed an array of neuroimaging techniques, but still yields divergent findings. This may be due in part to MCI's broad definition, encompassing heterogeneous cognitive domains, only some of which are affected in Parkinson's disease. Most domains falling under the MCI umbrella include fronto-dependent executive functions, whereas others, notably learning, rely on the basal ganglia. Given the deterioration of the nigrostriatal dopaminergic system in Parkinson's disease, it has been the prime target of PD-MCI investigation. By testing well defined cognitive deficits in Parkinson's disease, distinct functions can be attributed to specific neural systems, overcoming conflicting results on PD-MCI. Apart from dopamine, other systems such as the neurovascular or noradrenergic systems are affected in Parkinson's disease. These factors may be at the basis of specific facets of PD-MCI for which dopaminergic involvement has not been conclusive. Finally, the impact of both dopaminergic and noradrenergic deficiency on motivational states in Parkinson's disease is examined in light of a plausible link between apathy and cognitive deficits.

Depression as a risk factor for cognitive impairment in later life: the Health In Men cohort study

BACKGROUND

Depression is an established risk factor for dementia in later life, but it is unclear if this relationship is causal. This study aimed to determine if clinically significant depressive symptoms are likely to be causally related to cognitive impairment in later life.

METHODS

Observational cohort study of 4568 men aged 70-89 years living in Perth, Western Australia, who were free of cognitive impairment at the beginning of follow-up. Current clinically significant depressive symptoms were defined by a score of 7 or more on the Geriatric Depression Scale 15 items. Past depression was ascertained via electronic medical records, by self-report or use of antidepressants. A score of 27 or less on the Telephone Interview for Cognitive Status modified or a recorded diagnosis of dementia in electronic medical records established the presence of cognitive impairment.

RESULTS

During the 5-year follow-up, 534 men developed cognitive impairment, 811 died and 1455 were lost. The presence of clinically significant depressive symptoms at study entry was associated with increased risk rate (RR) of cognitive impairment (RR = 2.59, 95% confidence interval: 95%CI = 1.57-4.27), death (RR = 5.07, 95%CI = 3.32-7.75) and loss to follow-up (RR = 2.03, 95%CI = 1.32-3.13). These associations remained statistically significant after adjustment for age, country of birth, education, smoking history, and prevalence hypertension, diabetes, coronary heart disease and stroke. History of past clinically significant depressive symptoms was not associated with incident cognitive impairment (RR = 1.09, 95%CI = 0.78-1.52).

CONCLUSIONS

The lack of association between past depression and cognitive impairment suggests that the link between depression and cognitive impairment is not causal and that the presence of clinically significant depressive symptoms in later life may herald the onset of cognitive impairment in at least some people.

Mild Cognitive Impairment

PURPOSE OF REVIEW

As individuals age, the quality of cognitive function becomes an increasingly important topic. The concept of mild cognitive impairment (MCI) has evolved over the past 2 decades to represent a state of cognitive function between that seen in normal aging and dementia. As such, it is important for health care providers to be aware of the condition and place it in the appropriate clinical context.

RECENT FINDINGS

Numerous international population-based studies have been conducted to document the frequency of MCI, estimating its prevalence to be between 15% and 20% in persons 60 years and older, making it a common condition encountered by clinicians. The annual rate in which MCI progresses to dementia varies between 8% and 15% per year, implying that it is an important condition to identify and treat. In those MCI cases destined to develop Alzheimer disease, biomarkers are emerging to help identify etiology and predict progression. However, not all MCI is due to Alzheimer disease, and identifying subtypes is important for possible treatment and counseling. If treatable causes are identified, the person with MCI might improve.

SUMMARY

MCI is an important clinical entity to identify, and while uncertainties persist, clinicians need to be aware of its diagnostic features to enable them to counsel patients. MCI remains an active area of research as numerous randomized controlled trials are being conducted to develop effective treatments.

How older adults with mild cognitive impairment relate to technology as part of present and future everyday life: a qualitative study

BACKGROUND

Existing everyday technology as well as potential future technology may offer both challenges and possibilities in the everyday occupations of persons with cognitive decline. To meet their wishes and needs, the perspective of the persons themselves is an important starting point in intervention planning involving technology. The aim of this study was to explore how persons with mild cognitive impairment relate to technology as a part of and as potential support in everyday life - both present and future.

METHODS

Qualitative in-depth interviews with six participants aged 61-86 were conducted and analyzed, using a grounded theory approach.

RESULTS

The findings describe the participants' different ways of relating to existing and potential future technology in everyday occupations as a continuum of downsizing, retaining, and updating. Multiple conditions in different combinations affected both their actions taken and assumptions made towards technology in this continuum. Both when downsizing doing and technology use to achieve simplicity in everyday life and when striving for or struggling with updating, trade-offs between desired and adverse outcomes were made, challenging take-off runs were endured, and negotiations of the price worth paying took place.

CONCLUSIONS

Our findings suggest that persons with mild cognitive impairment may relate to technology in various ways to meet needs of downsized doing, but are reluctant to adopt video-based monitoring technology intended to support valued occupations. Feasibility testing of using already-incorporated everyday technologies such as smartphones and tablets as platforms for future technology support in everyday occupations is suggested.

Altered Frontal Lateralization Underlies the Category Fluency Deficits in Older Adults with Mild Cognitive Impairment: A Near-Infrared Spectroscopy Study

Individuals with mild cognitive impairment (MCI) have been consistently found to have category fluency deficits. However, little is known about the neural basis of these deficits. A diversity of neuroimaging studies has revealed left-lateralized prefrontal activations due to verbal processing and control functions during the performance of category fluency tasks. Given the reports of structural and functional abnormalities in the prefrontal cortices in individuals with MCI, it is conceivable that these individuals would also exhibit altered prefrontal activation patterns during a category fluency task. The present study aimed to investigate the prefrontal dynamics during the category fluency task in older adults with MCI by using near-infrared spectroscopy (NIRS). Twenty-six older adults with MCI were compared with 26 older adults with normal cognition (NC) who were matched in age, gender, handedness, and educational level. All participants performed a category fluency task while the prefrontal dynamics were recorded. The results showed that the MCI group generated fewer unique words, made fewer switches between subcategories, and generated fewer new subcategories than did the NC group. Importantly, the NIRS results showed that the NC group exhibited a left lateralization of frontal activations during the category fluency task, while the MCI group did not exhibit such a lateralization. Furthermore, there was a significant positive correlation between the category fluency performance and the extent of lateralization, suggesting that the category fluency deficits in the MCI group could be related to frontal dysfunction. That is, the rightward shift of frontal activations in the MCI group may reflect the presence of cortical reorganization in which the contralateral regions (i.e., the right hemisphere) are recruited to take over the function that is declining in the specialized regions (i.e., the left hemisphere). Our lateralization finding may serve as an objective neural marker for distinguishing between normal aging and MCI. Our study highlights that an alteration of neural functioning is already present at the prodromal stage of dementia.

Weight Loss Predicts Progression of Mild Cognitive Impairment to Alzheimer's Disease

Background

Weight loss is common in people with Alzheimer’s disease (AD) and it could be a marker of impending AD in Mild Cognitive Impairment (MCI) and improve prognostic accuracy, if accelerated progression to AD would be shown.

Aims

To assess weight loss as a predictor of dementia and AD in MCI.

Methods

One hundred twenty-five subjects with MCI (age 73.8 ± 7.1 years) were followed for an average of 4 years. Two weight measurements were carried out at a minimum time interval of one year. Dementia was defined according to DSM-IV criteria and AD according to NINCDS-ADRDA criteria. Weight loss was defined as a ≥4% decrease in baseline weight.

Results

Fifty-three (42.4%) MCI progressed to dementia, which was of the AD-type in half of the cases. Weight loss was associated with a 3.4-fold increased risk of dementia (95% CI = 1.5–6.9) and a 3.2-fold increased risk of AD (95% CI = 1.4–8.3). In terms of years lived without disease, weight loss was associated to a 2.3 and 2.5 years earlier onset of dementia and AD.

Conclusions

Accelerated progression towards dementia and AD is expected when weight loss is observed in MCI patients. Weight should be closely monitored in elderly with mild cognitive impairment.