Diagnosing Mild Cognitive Impairment (MCI) in clinical trials: a systematic review

Socially Assistive Robots for patients with Alzheimer's Disease: A scoping review

BACKGROUND

The most common form of dementia, Alzheimer's Disease (AD), is challenging for both those affected as well as for their care providers, and caregivers. Socially assistive robots (SARs) offer promising supportive care to assist in the complex management associated with AD.

OBJECTIVES

To conduct a scoping review of published articles that proposed, discussed, developed or tested SAR for interacting with AD patients.

METHODS

We performed a scoping review informed by the methodological framework of Arksey and O'Malley and adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist for reporting the results. At the identification stage, an information specialist performed a comprehensive search of 8 electronic databases from the date of inception until January 2022 in eight bibliographic databases. The inclusion criteria were all populations who recive or provide care for AD, all interventions using SAR for AD and our outcomes of inteerst were any outcome related to AD patients or care providers or caregivers. All study types published in the English language were included.

RESULTS

After deduplication, 1251 articles were screened. Titles and abstracts screening resulted to 252 articles. Full-text review retained 125 included articles, with 72 focusing on daily life support, 46 on cognitive therapy, and 7 on cognitive assessment.

CONCLUSION

We conducted a comprehensive scoping review emphasizing on the interaction of SAR with AD patients, with a specific focus on daily life support, cognitive assessment, and cognitive therapy. We discussed our findings' pertinence relative to specific populations, interventions, and outcomes of human-SAR interaction on users and identified current knowledge gaps in SARs for AD patients.

Examining the role of participant and study partner report in widely-used classification approaches of mild cognitive impairment in demographically-diverse community dwelling individuals: results from the Einstein aging study

Objective

The role of subjective cognitive concerns (SCC) as a diagnostic criterion for MCI remains uncertain and limits the development of a universally (or widely)-accepted MCI definition. The optimal MCI definition should define an at-risk state and accurately predict the development of incident dementia. Questions remain about operationalization of definitions of self- and informant-reported SCCs and their individual and joint associations with incident dementia.

Methods

The present study included Einstein Aging Study participants who were non-Hispanic White or Black, free of dementia at enrollment, had follow-up, and completed neuropsychological tests and self-reported SCC at enrollment to determine MCI status. Informant-reported SCC at baseline were assessed via the CERAD clinical history questionnaire. Self-reported SCC were measured using the CERAD, items from the EAS Health Self-Assessment, and the single memory item from the Geriatric Depression Scale. Cox proportional hazards models examined the association of different operationalizations of SCC with Petersen and Jak/Bondi MCI definitions on the risk of dementia, further controlling for age, sex, education, and race/ethnicity. Time-dependent sensitivity and specificity at specific time points for each definition, and Youden's index were calculated as an accuracy measure. Cox proportional hazards models were also used to evaluate the associations of combinations of self- and informant-reported SCC with the risk of incident dementia.

Results

91% of the sample endorsed at least one SCC. Youden's index showed that not including SCC in either Jak/Bondi or Petersen classifications had the best balance between sensitivity and specificity across follow-up. A subset of individuals with informants, on average, had a lower proportion of non-Hispanic Blacks and 94% endorsed at least one self-reported SCC. Both informant-reported and self-reported SCC were significantly associated with incident dementia.

Conclusion

Our findings suggest that the SCC criterion may not improve the predictive validity for dementia when included in widely-employed definitions of MCI. Consistent with some prior research, informant-reported SCC was more related to risk of incident dementia than self-reported SCC. Given that requiring informant report as a diagnostic criterion may unintentionally exclude health disparate groups, additional consideration is needed to determine how best to utilize informant-report in MCI diagnosis.

Association Between Neuropsychological Functions and Activities of Daily Living in People with Mild Cognitive Impairment

OBJECTIVE

The aim of this study was to explore the relationship between performance in neurocognitive variables and daily functioning (basic or b- and instrumental or i-ADL) in people with mild cognitive impairment (MCI).

METHODS

A sample of 157 participants with MCI (73.65 ± 7.58 years) completed a battery of tests for assessing ADL and cognitive functions. t-test, Pearson's correlation and multiple linear regression (backward stepwise selection) were used for data analyses.

RESULTS

Significant correlations were found between b- and i-ADL, and several neuropsychological tests (p < .01). Multivariate analysis showed that difficulties in Blessed Rating Scales (BLS) explained 33.2% of the variation in b-ADL and that this variation rises to 42.9% when BLS is associated with Frontal Assessment Battery Flexibility, Trail Making Test A (TMT-A) and BLS Personality. For i-ADL, BLS and Dementia Rating Scale Total (DRS-T) explained 47.7% of the variation and the inclusion in the model of BLS, DRS-IP (Initiation/Perseveration), TMT-A and BLS Personality explained 53.5% of this variation. Executive functions explained 24.8% of the variation in i-ADL.

CONCLUSIONS

Cognitive functions are related to i- and b-ADL in people with MCI. The general indicators and those that assess executive functions and verbal- or visual-spatial memory should be considered to predict i-ADL.

Effects of Home-Based Computerized Cognitive Training in Community-Dwelling Adults With Mild Cognitive Impairment

OBJECTIVE

There is a growing importance for the home-based (HB) support services, and computerized cognitive training (CCT) has been reported as an effective intervention for cognitive impairment. However, there is still a need for further verification of the effect of HB-CCT. This study aimed to determine the effectiveness of HB-CCT on the cognitive function of community-dwelling adults with mild cognitive impairment (MCI) as well as safety in its use.

METHODS

Fifty community-dwelling adults with MCI were included, of which 25 each were randomized to either HB-CCT or control groups. Evaluations of comprehensive cognition, memory, attention, language, executive function, and depression were performed before and after the intervention, including three times a week for eight weeks in the intervention group and eight weeks apart with no intervention in the control group.

RESULTS

In baseline and post-evaluation comparisons, the HB-CCT group showed significant improvements, while the control group did not show significant changes. Statistically significant variations were noted between the HB-CCT and control groups in all post-intervention evaluations relative to baseline. Additionally, no side effects were observed.

CONCLUSION

Beneficial effects on cognition and depression were noted in the intervention group compared with the control group, suggesting that HB-CCT may be a positive tool for cognitive improvement in adults with MCI.

Gamma neuromodulation improves episodic memory and its associated network in amnestic mild cognitive impairment: a pilot study

Amnestic mild cognitive impairment (aMCI) is a predementia stage of Alzheimer's disease associated with dysfunctional episodic memory and limited treatment options. We aimed to characterize feasibility, clinical, and biomarker effects of noninvasive neurostimulation for aMCI. 13 individuals with aMCI received eight 60-minute sessions of 40-Hz (gamma) transcranial alternating current stimulation (tACS) targeting regions related to episodic memory processing. Feasibility, episodic memory, and plasma Alzheimer's disease biomarkers were assessed. Neuroplastic changes were characterized by resting-state functional connectivity (RSFC) and neuronal excitatory/inhibitory balance. Gamma tACS was feasible and aMCI participants demonstrated improvement in multiple metrics of episodic memory, but no changes in biomarkers. Improvements in episodic memory were most pronounced in participants who had the highest modeled tACS-induced electric fields and exhibited the greatest changes in RSFC. Increased RSFC was also associated with greater hippocampal excitability and higher baseline white matter integrity. This study highlights initial feasibility and the potential of gamma tACS to rescue episodic memory in an aMCI population by modulating connectivity and excitability within an episodic memory network.

A graph theoretic approach to neurodegeneration: five data-driven neuropsychological subtypes in mild cognitive impairment

Mild cognitive Impairment (MCI) is notoriously heterogenous in terms of clinical presentation, neuroimaging correlates, and subsequent progression. Predicting who will progress to dementia, which type of dementia, and over what timeframe is challenging. Previous work has attempted to identify MCI subtypes using neuropsychological measures in an effort to address this challenge; however, there is no consensus on approach, which may account for some of the variability. Using a hierarchical community detection approach, we examined cognitive subtypes within an MCI sample (from the Alzheimer's Disease Neuroimaging Initiative [ADNI] study). We then examined whether these subtypes were related to biomarkers (e.g., cortical volumes, fluorodeoxyglucose (FDG)-positron emission tomography (PET) hypometabolism) or clinical progression. We identified five communities (i.e., cognitive subtypes) within the MCI sample: 1) predominantly memory impairment, 2) predominantly language impairment, 3) cognitively normal, 4) multidomain, with notable executive dysfunction, 5) multidomain, with notable processing speed impairment. Community membership was significantly associated with 1) cortical volume in the hippocampus, entorhinal cortex, and fusiform cortex; 2) FDG PET hypometabolism in the posterior cingulate, angular gyrus, and inferior/middle temporal gyrus; and 3) conversion to dementia at follow up. Overall, community detection as an approach appears a viable method for identifying unique cognitive subtypes in a neurodegenerative sample that were linked to several meaningful biomarkers and modestly with progression at one year follow up.

Relationship between Cognitive Impairment and Depressive Symptoms with Somatosensory Functions in Diabetic and Non-Diabetic Older Adults and Its Impact on Quality of Life

Aging is an inevitable process that impacts the peripheral and central nervous systems and is considered one of the strongest risk factors for neurodegenerative diseases. In addition, when it also presents with diabetes mellitus, the risk of neurological damage may be further increased. This current study aimed to explore the relationships between peripheral sensory system decline and cognitive functions, the symptoms of depression, and quality of life (QoL) as metrics of central nervous system impairment in institutionalized older adults. A total of 95 individuals participated in this case-control study, which included diabetics and non-diabetics. The superficial sensory pathway was assessed in terms of thermal sensation, nociception, and non-discriminative touch, and the deep sensory pathway was evaluated by assessing vibration and light touch-pressure sensations. To assess function at the intellectual level, the Mini-Mental State Examination (MMSE) and Trail Making Test (TMT) cognitive functional tests were used, while the symptoms of depression and QoL were explored by employing the Yesavage Geriatric Depression Scale and EuroQol 5D questionnaire (EQ-5D), respectively. In the overall population analyses, altered thermal sensation was significantly associated with cognitive impairment (CI; p < 0.05). In turn, bivariate analyses and a binary logistic regression showed that the symptoms of depression and QoL were significantly related to altered vibratory sensation when assessed using a medical tuning fork (p < 0.05). In the group of diabetic patients, those with CI also had significantly lower thermal sensation (p < 0.05) and non-discriminative touch sensation, although this was only a trend (p = 0.055). Diabetics with depression had a significantly worse non-discriminative touch (p < 0.05) and vibratory sensation when tested with a tuning fork (p < 0.05). In addition, poorer QoL was associated with reduced sensitivity to heat (p < 0.05), light touch pressure (p < 0.05), and vibrations when assessed either with a tuning fork (p < 0.05) or a biothesiometer (p < 0.05). In contrast, no relationships were found between sensory functions and cognitive assessments in non-diabetic patients. These findings indicate that superficial sensitivity damage was related to CI, while deep sensation alterations were related to depression and poor QoL, with diabetes apparently further strengthening these relationships.

The Ability to Use Contextual Information in Object and Scene Recognition in Patients with Mild Cognitive Impairment

BACKGROUND

The ability to understand and make use of object-scene relationships are critical for object and scene recognition.

OBJECTIVE

The current study assessed whether patients with mild cognitive impairment (MCI), possibly in the preclinical phase of Alzheimer's disease, exhibited impairment in processing contextual information in scene and object recognition.

METHODS

In Experiment 1, subjects viewed images of foreground objects in either semantic consistent or inconsistent scenes under no time pressure, and they verbally reported the names of foreground objects and backgrounds. Experiment 2 replicated Experiment 1, except that subjects were required to name scene first. Experiment 3 examined object and scene recognition accuracy baselines, recognition difficulty, familiarity with objects/scenes, and object-scene consistency judgements.

RESULTS

There were contextual consistency effects on scene recognition for MCI and healthy subjects, regardless of response sequence. Scenes were recognized more accurately under the consistent condition than the inconsistent condition. Additionally, MCI patients were more susceptible to incongruent contextual information, possibly due to inhibitory deficits or over-dependence on semantic knowledge. However, no significant differences between MCI and healthy subjects were observed in consistency judgement, recognition accuracy, recognition difficulty and familiarity rating, suggesting no significant impairment in object and scene knowledge among MCI subjects.

CONCLUSIONS

The study indicates that MCI patients retain relatively intact contextual processing ability but may exhibit inhibitory deficits or over-reliance on semantic knowledge.

Associations of Multidomain Interventions With Improvements in Cognition in Mild Cognitive Impairment: A Systematic Review and Meta-analysis

IMPORTANCE

Older adults with mild cognitive impairment (MCI) have the highest risk of progressing to dementia. Evidence suggests that nonpharmacological, single-domain interventions can prevent or delay progressive declines, but it is unclear whether greater cognitive benefits arise from multidomain interventions.

OBJECTIVE

To determine whether multidomain interventions, composed of 2 or more interventions, are associated with greater improvements in cognition among older adults with MCI than a single intervention on its own.

DATA SOURCES

MEDLINE, Embase, PsycInfo, AgeLine, CINAHL, and Cochrane Central Register of Controlled Trials were systematically searched from database inception to December 20, 2021.

STUDY SELECTION

Included studies contained (1) an MCI diagnosis; (2) nonpharmacological, multidomain interventions that were compared with a single active control; (3) older adults aged 65 years and older; and (4) randomized clinical trials.

DATA EXTRACTION AND SYNTHESIS

Data were screened and extracted by 3 independent reviewers. Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, random-effects meta-analyses were used to calculate effect sizes from the standardized mean difference (SMD) and 95% CIs.

MAIN OUTCOMES AND MEASURES

Postintervention cognitive test scores in 7 cognitive domains were compared between single-domain and multidomain groups. Exposure to the intervention was analyzed.

RESULTS

A total of 28 studies published between 2011 and 2021, including 2711 older adults with MCI, reported greater effect sizes in the multidomain group for global cognition (SMD, 0.41; 95% CI, 0.23-0.59; P < .001), executive function (SMD, 0.20; 95% CI, 0.04-0.36; P = .01), memory (SMD, 0.29; 95% CI, 0.14-0.45; P < .001), and verbal fluency (SMD, 0.30; 95% CI, 0.12-0.49; P = .001). The Mini-Mental State Examination (SMD, 0.40; 95% CI, 0.17-0.64; P < .001), category verbal fluency test (SMD, 0.34; 95% CI, 0.13-0.56; P = .002), Trail Making Test-B (SMD, 0.46; 95% CI, 0.13-0.80; P = .007), and Wechsler Memory Scale-Logical Memory I (SMD, 0.47; 95% CI, 0.15-0.80; P < .001) and II (SMD, 0.26; 95% CI, 0.07-0.45; P < .001) favored the multidomain group. Exposure to the intervention varied between studies: the mean (SD) duration was 71.3 (36.0) minutes for 19.8 (14.6) weeks with sessions taking place 2.5 (1.1) times per week, and all interventions lasted less than 1 year.

CONCLUSIONS AND RELEVANCE

In this study, short-term multidomain interventions (<1 year) were associated with improvements in global cognition, executive function, memory, and verbal fluency compared with single interventions in older adults with MCI.

Psychological treatments for depression and anxiety in dementia and mild cognitive impairment

BACKGROUND

Experiencing anxiety and depression is very common in people living with dementia and mild cognitive impairment (MCI). There is uncertainty about the best treatment approach. Drug treatments may be ineffective and associated with adverse effects. Guidelines recommend psychological treatments. In this updated systematic review, we investigated the effectiveness of different psychological treatment approaches.

OBJECTIVES

Primary objective To assess the clinical effectiveness of psychological interventions in reducing depression and anxiety in people with dementia or MCI. Secondary objectives To determine whether psychological interventions improve individuals' quality of life, cognition, activities of daily living (ADL), and reduce behavioural and psychological symptoms of dementia, and whether they improve caregiver quality of life or reduce caregiver burden.

SEARCH METHODS

We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group's register, MEDLINE, Embase, four other databases, and three trials registers on 18 February 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared a psychological intervention for depression or anxiety with treatment as usual (TAU) or another control intervention in people with dementia or MCI.

DATA COLLECTION AND ANALYSIS

A minimum of two authors worked independently to select trials, extract data, and assess studies for risk of bias. We classified the included psychological interventions as cognitive behavioural therapies (cognitive behavioural therapy (CBT), behavioural activation (BA), problem-solving therapy (PST)); 'third-wave' therapies (such as mindfulness-based cognitive therapy (MBCT)); supportive and counselling therapies; and interpersonal therapies. We compared each class of intervention with control. We expressed treatment effects as standardised mean differences or risk ratios. Where possible, we pooled data using a fixed-effects model. We used GRADE methods to assess the certainty of the evidence behind each result.

MAIN RESULTS

We included 29 studies with 2599 participants. They were all published between 1997 and 2020. There were 15 trials of cognitive behavioural therapies (4 CBT, 8 BA, 3 PST), 11 trials of supportive and counselling therapies, three trials of MBCT, and one of interpersonal therapy. The comparison groups received either usual care, attention-control education, or enhanced usual care incorporating an active control condition that was not a specific psychological treatment. There were 24 trials of people with a diagnosis of dementia, and five trials of people with MCI. Most studies were conducted in community settings. We considered none of the studies to be at low risk of bias in all domains.  Cognitive behavioural therapies (CBT, BA, PST) Cognitive behavioural therapies are probably slightly better than treatment as usual or active control conditions for reducing depressive symptoms (standardised mean difference (SMD) -0.23, 95% CI -0.37 to -0.10; 13 trials, 893 participants; moderate-certainty evidence). They may also increase rates of depression remission at the end of treatment (risk ratio (RR) 1.84, 95% CI 1.18 to 2.88; 2 studies, with one study contributing 2 independent comparisons, 146 participants; low-certainty evidence). We were very uncertain about the effect of cognitive behavioural therapies on anxiety at the end of treatment (SMD -0.03, 95% CI -0.36 to 0.30; 3 trials, 143 participants; very low-certainty evidence). Cognitive behavioural therapies probably improve patient quality of life (SMD 0.31, 95% CI 0.13 to 0.50; 7 trials, 459 participants; moderate-certainty evidence) and activities of daily living at end of treatment compared to treatment as usual or active control (SMD -0.25, 95% CI -0.40 to -0.09; 7 trials, 680 participants; moderate-certainty evidence). Supportive and counselling interventions Meta-analysis showed that supportive and counselling interventions may have little or no effect on depressive symptoms in people with dementia compared to usual care at end of treatment (SMD -0.05, 95% CI -0.18 to 0.07; 9 trials, 994 participants; low-certainty evidence). We were very uncertain about the effects of these treatments on anxiety, which was assessed only in one small pilot study. Other interventions There were very few data and very low-certainty evidence on MBCT and interpersonal therapy, so we were unable to draw any conclusions about the effectiveness of these interventions.

AUTHORS' CONCLUSIONS

CBT-based treatments added to usual care probably slightly reduce symptoms of depression for people with dementia and MCI and may increase rates of remission of depression. There may be important effect modifiers (degree of baseline depression, cognitive diagnosis, or content of the intervention). CBT-based treatments probably also have a small positive effect on quality of life and activities of daily living. Supportive and counselling interventions may not improve symptoms of depression in people with dementia. Effects of both types of treatment on anxiety symptoms are very uncertain. We are also uncertain about the effects of other types of psychological treatments, and about persistence of effects over time. To inform clinical guidelines, future studies should assess detailed components of these interventions and their implementation in different patient populations and in different settings.

Midlife Vascular Factors and Prevalence of Mild Cognitive Impairment in Late-Life in Mexico

OBJECTIVE

To estimate the prevalence of mild cognitive impairment (MCI) and its subtypes and investigate the impact of midlife cardiovascular risk factors on late-life MCI among the aging Mexican population.

METHOD

Analyses included a sample of non-demented adults over the age of 55 living in both urban and rural areas of Mexico (N = 1807). MCI diagnosis was assigned based on a comprehensive cognitive assessment assessing the domains of memory, executive functioning, language, and visuospatial ability. The normative sample was selected by means of the robust norms approach. Cognitive impairment was defined by a 1.5-SD cut-off per cognitive domain using normative corrections for age, years of education, and sex. Risk factors included age, education, sex, rurality, depression, insurance status, workforce status, hypertension, diabetes, stroke, and heart disease.

RESULTS

The prevalence of amnestic MCI was 5.9%. Other MCI subtypes ranged from 4.2% to 7.7%. MCI with and without memory impairment was associated with older age (OR = 1.01 [1.01, 1.05]; OR = 1.03 [1.01, 1.04], respectively) and residing in rural areas (OR = 1.49 [1.08, 2.06]; OR = 1.35 [1.03, 1.77], respectively). Depression (OR = 1.07 [1.02, 1.12]), diabetes (OR = 1.37 [1.03, 1.82]), and years of education (OR = 0.94 [0.91, 0.97]) were associated with MCI without memory impairment. Midlife CVD increased the odds of MCI in late-life (OR = 1.76 [1.19, 2.59], which was driven by both midlife hypertension and diabetes (OR = 1.70 [1.18, 2.44]; OR = 1.88 [1.19, 2.97], respectively).

CONCLUSIONS

Older age, depression, low education, rurality, and midlife hypertension and diabetes were associated with higher risk of late-life MCI among older adults in Mexico. Our findings suggest that the causes of cognitive impairment are multifactorial and vary by MCI subtype.

A cross-sectional study of memory and executive functions in patients with sporadic inclusion body myositis

INTRODUCTION/AIMS

Sporadic inclusion body myositis (IBM) is a degenerative and inflammatory acquired myopathy characterized by muscle deposition of various proteins typically associated with Alzheimer disease and other neurodegenerative diseases. Although cognitive impairment is not noted as a clinical feature of IBM, evidence is lacking. In this study we investigated whether cognitive performance of patients with IBM differs from population norms, focusing on cognitive domains affected in early Alzheimer disease (memory, executive function), and to test whether disease duration and the level of disability of IBM are associated with cognitive function.

METHODS

Twenty-four patients with IBM (mean [standard deviation]: age, 62.0 [7.2] years; disease duration, 9.6 [4.8] years) were assessed cross-sectionally on neuropsychological tests covering multiple cognitive domains, including the Preclinical Alzheimer Cognitive Composite (PACC). Performance was compared with published normative data adjusted for age, sex, and education (National Alzheimer's Coordinating Center; N = 3268). Associations were examined between PACC score, disease duration, and level of disability (assessed using the IBM Functional Rating Scale [IBMFRS]).

RESULTS

Across all cognitive tests, group performance was within ±1 standard deviation of the normative mean. There was no evidence of associations between PACC score and either disease duration (ρ = -0.04, P = .87) or IBMFRS total score (ρ = 0.14, P = .52).

DISCUSSION

Memory and executive function in patients with IBM did not differ from normative data, and we observed no evidence of associations between the cognitive composite and disease duration or level of disability. This addresses a question frequently asked by patients and will be of value for clinicians and patients alike.

Deep learning improves utility of tau PET in the study of Alzheimer's disease

INTRODUCTION

Positron emission tomography (PET) imaging targeting neurofibrillary tau tangles is increasingly used in the study of Alzheimer's disease (AD), but its utility may be limited by conventional quantitative or qualitative evaluation techniques in earlier disease states. Convolutional neural networks (CNNs) are effective in learning spatial patterns for image classification.

METHODS

18F-MK6240 (n = 320) and AV-1451 (n = 446) PET images were pooled from multiple studies. We performed iterations with differing permutations of radioligands, heuristics, and architectures. Performance was compared to a standard region of interest (ROI)-based approach on prediction of memory impairment. We visualized attention of the network to illustrate decision making.

RESULTS

Overall, models had high accuracy (> 80%) with good average sensitivity and specificity (75% and 82%, respectively), and had comparable or higher accuracy to the ROI standard. Visualizations of model attention highlight known characteristics of tau radioligand binding.

DISCUSSION

CNNs could improve tau PET's role in early disease and extend the utility of tau PET across generations of radioligands.

Burning Fog: Cognitive Impairment in Burning Mouth Syndrome

Background: Due to its common association with chronic pain experience, cognitive impairment (CI) has never been evaluated in patients with burning mouth syndrome (BMS). The purpose of this study is to assess the prevalence of CI in patients with BMS and to evaluate its relationship with potential predictors such as pain, mood disorders, blood biomarkers, and white matter changes (WMCs).

Methods: A case-control study was conducted by enrolling 40 patients with BMS and an equal number of healthy controls matched for age, gender, and education. Neurocognitive assessment [Mini Mental State Examination (MMSE), Digit Cancellation Test (DCT), the Forward and Backward Digit Span task (FDS and BDS), Corsi Block-Tapping Test (CB-TT), Rey Auditory Verbal Learning Test (RAVLT), Copying Geometric Drawings (CGD), Frontal Assessment Battery (FAB), and Trail Making A and B (TMT-A and TMT-B)], psychological assessment [Hamilton Rating Scale for Depression and Anxiety (HAM-D and HAM-A), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and 36-Item Short Form Health Survey (SF-36)], and pain assessment [Visual Analogic Scale (VAS), Total Pain Rating index (T-PRI), Brief Pain Inventory (BPI), and Pain DETECT Questionnaire (PD-Q)] were performed. In addition, blood biomarkers and MRI of the brain were recorded for the detection of Age-Related WMCs (ARWMCs). Descriptive statistics, the Mann-Whitney U-test, the Pearson Chi-Squared test and Spearman's correlation analysis were used.

Results: Patients with BMS had impairments in most cognitive domains compared with controls (p < 0.001^**) except in RAVLT and CGD. The HAM-D, HAM-A, PSQI, ESS, SF-36, VAS, T-PRI, BPI and PD-Q scores were statistically different between BMS patients and controls (p < 0.001^**) the WMCs frequency and ARWMC scores in the right temporal (RT) and left temporal (LT) lobe were higher in patients with BMS (p = 0.023^*).

Conclusions: Meanwhile, BMS is associated with a higher decline in cognitive functions, particularly attention, working memory, and executive functions, but other functions such as praxis-constructive skills and verbal memory are preserved. The early identification of CI and associated factors may help clinicians to identify patients at risk of developing time-based neurodegenerative disorders, such as Alzheimer's disease (AD) and vascular dementia (VD), for planning the early, comprehensive, and multidisciplinary assessment and treatment.

High-Ecological Cognitive Intervention to Improve Cognitive Skills and Cognitive-Functional Performance for Older Adults With Mild Cognitive Impairment

IMPORTANCE

Evidence of the effectiveness of cognitive activity and preparatory tasks in improving the cognitive skills and functional performance of people with cognitive decline is limited.

OBJECTIVE

To examine the efficacy of a high-ecological cognitive intervention.

DESIGN

Quasi-experimental, pretest-posttest design with nonequivalent control.

SETTING

Community.

PARTICIPANTS

Older adults with mild cognitive impairment from two senior centers.

INTERVENTION

Twelve 90-min weekly group sessions of a high-ecological cognitive intervention using simulated everyday cognitive tasks (experimental group) and of nutrition education (active control group). Outcomes and Measures: Cognitive skills were measured with the Color Trails Test (CTT), the Contextual Memory Test (CMT; Immediate Recall [CMT-Im] and Delayed Recall [CMT-De] tasks), and the Wechsler Adult Intelligence Scale-Fourth Edition Digit Span subtest (Digits Forward and Digits Backward). Cognitive-functional performance was measured with the Rivermead Behavioural Memory Test-Third Edition (RBMT-3; Immediate Recall [RBMT-3-Im] and Delayed Recall [RBMT-3-De] tasks) and the Cognitive Failures Questionnaire (CFQ).

RESULTS

Thirty-seven participants (M age = 70.84 yr; 70.3% women) met the inclusion criteria for analysis (20 participants in the intervention group, 17 participants in the control group). Multivariate linear regression showed that the intervention group improved significantly more than the control group on the CTT, CMT-Im, and RBMT-3-Im but not on the CMT-De, RBMT-3-De, and CFQ.

CONCLUSIONS AND RELEVANCE

Twelve 90-min weekly group sessions of a high-ecological cognitive intervention improved attention, executive function, immediate memory, and objective cognitive-functional performance with immediate-memory task demands. What This Article Adds: Carefully designed and structured simulated everyday cognitive tasks can be used as a cognitive training agent to improve both cognitive skills and objective cognitive-functional performance. The effectiveness of group-based cognitive interventions depends on the skills of occupational therapy practitioners in activity analysis and grading.

The Persian Version of the Quick Mild Cognitive Impairment Screen (Qmci-Pr): Psychometric Properties among Middle-Aged and Older Iranian Adults

Brief cognitive screening instruments are used to identify patients presenting with cognitive symptoms that warrant further assessment. This study aimed to evaluate the reliability and validity of the Persian version of the Quick Mild Cognitive Impairment (Qmci-Pr) among middle-aged and older Iranian adults. Consecutive patients aged ≥55 years and caregivers attending with them as normal controls (NCs) were recruited from geriatric outpatient clinics and a hospital in Tehran, Iran. All patients completed the Qmci-Pr before completing an independent detailed neuropsychological assessment and staging using the Clinical Dementia Rating (CDR) Scale. NCs underwent the same assessment. In all, 92 participants with a median age of 70 years (±13) were available. Of these, 20 participants were NCs, 24 had subjective memory complaints (SMC), 24 had mild cognitive impairment (MCI), and 24 had Alzheimer's disease (AD). The Qmci-Pr had good accuracy in differentiating SMC and NC from MCI (area under the curve (AUC): 0.80 (0.69-0.91)) and in identifying cognitive impairment (MCI and mild AD) (AUC: 0.87 (0.80-0.95)) with a sensitivity of 88% and specificity of 80%, at an optimal cut-off of <53/100. The Qmci-Pr is an accurate short cognitive screening impairment for separating NC and patients with SMC from MCI and identifying cognitive impairment. Further research with larger samples and comparison with other widely used instruments such as the Montreal Cognitive Assessment is needed. Given its established brevity, the Qmci-Pr is a useful screen for Iranian adults across the spectrum of cognitive decline.

Challenges to recruitment of participants with MCI in a multicentric neuropsychological study

BACKGROUND

Data on recruitment of Mild Cognitive Impairment (MCI) samples are seldom reported and this issue can be an important source of research waste.

AIM

To describe the recruitment challenges and reasons for non-eligibility faced during a bi-centre clinical study assessing the predictive value of a neuropsychological battery of the progression to dementia.

METHODS

Potential MCI participants were identified from databases of the two memory clinics based in Milan (Italy) and invited to the screening assessment.

RESULTS

About 50% of the cases initially identified were ineligible according to inclusion/exclusion criteria and the two sites took 22 months to recruit the planned 150 people. The main reasons for non-eligibility were the MMSE score (41%), age (14%), presence of cerebrovascular disorders (9%), perceptual deficits (6%), neurological (6%) or psychiatric (4%) comorbidities and low education (5%).

CONCLUSION

Awareness of the reasons for exclusion and of the time needed to recruit the planned sample would provide hints for the planning of future studies on MCI.

New Contemplation Upon Subjective Memory Complaints as a Self- Report Criterion for MCI Diagnosis

BACKGROUND

Subjective memory complaints are a key component in mild cognitive impairment (MCI) diagnosis. However, studies that examined memory awareness among MCI participants have published contradictory results. One possible explanation for the inconsistent findings could be the disregard from the multidimensional structure of subjective memory.

OBJECTIVES

The present study is directed at assessing subjective memory among healthy and MCI participants, referring to three main types of memory: episodic, semantic, and working memory.

METHODS

Participants were 123 adults (aged 50-90). They were divided into two groups, the MCI group, and the control group, according to their objective cognitive performance in RAVL or Mo- CA tests. All participants filled a subjective memory questionnaire, assessing their awareness of episodic, semantic, and working memory.

RESULTS

MCI participants estimated their semantic memory as significantly lower in comparison to the estimation of the healthy controls. By contrast, MCI participants showed an overestimation of their episodic memory capabilities compared to the control group. No significant difference was found between groups (MCI and healthy controls) in evaluating their working memory. In addition, for both groups, Pearson's correlation revealed a significant negative correlation between age and semantic memory evaluation. Such correlation was not found for subjective episodic memory.

DISCUSSION

Findings suggest that while people with MCI exhibit poor awareness of their episodic and working memory capabilities, their awareness of their decrease in semantic memory is apparently intact. Therefore, it is suggested that when using the self-report criterion for MCI diagnosis, clinicians should consider the patient's' semantic memory complaints.

Genetic and Environmental Contributors to Neurodegeneration: An Exploration of the Effects of Alcohol on Clinical Features of Huntington's Disease Using the Enroll-HD Global Platform

Huntington’s disease (HD) is a neurodegenerative dementia with a well recognised genetic cause. Alcohol misuse is a major environmental factor relevant to numerous neurological presentations, including HD. We explored the effects of alcohol intake on clinical features of HD by means of data from the Enroll-HD, which is a global registry study. A retrospective observational study making use of the Enroll-HD periodic dataset up to 2020 (in accordance with the Enroll-HD guidelines, encompassing 16,120 subjects with the HD gene (CAG expansion > 36), was carried out. This included 180 sites in 21 countries. The study looked at the association of alcohol use with the clinical presentation of HD, specifically looking into the age of first symptoms and HD severity. We also describe a specific case with manifest HD, a participant in the Enroll-HD study, whereby the patient’s obsessionality was central to her pattern of high alcohol intake and to her successful avoidance of alcohol thereafter. A record of past problems with high alcohol intake was more common in the group with manifest HD (9.0%, n = 1121) when compared with the pre-manifest carriers of the HD genetic abnormality (2.3%, n = 339). Age at onset of symptoms was not significantly influenced by current alcohol misuse, or past misuse. The severity of clinical impairments in HD was influenced by alcohol. Patients who reported high alcohol intake in the past had a statistically significant increase in motor impairments, by the Unified Huntington’s Disease Rating Scale total motor score (Kruskal–Wallis, post hoc Dunn’s, p < 0.001), and a significantly higher burden of psychiatric symptoms by the Problem Behaviours Assessment score (Kruskal–Wallis, post hoc Dunn’s, p < 0.01) compared with those not reporting high alcohol use. However, the past alcohol group did not have a lower Mini Mental State Examination score (Kruskal–Wallis, post hoc Dunn’s, p > 0.05) The first symptom of HD, as determined by the assessing clinician, was more likely to be psychiatric disturbance in patients currently misusing alcohol or those with prior history of alcohol misuse (55% and 31% respectively) when compared with controls (5%). Individual case experience, such as that presented in this study, shows that HD and alcohol, two major genetic and environmental contributors to neurodegeneration, interact in producing clinical problems. However, the complexities of these interactions are difficult to define, and may require larger studies dedicated to exploring the various factors in this interaction.

Factors contributing to cognitive improvement effects of acupuncture in patients with mild cognitive impairment: a pilot randomized controlled trial

Background

Mild cognitive impairment (MCI) is generally regarded as the borderline between cognitive changes of aging and very early Alzheimer’s disease (AD). It is important to develop easily available interventions to delay the progression of MCI to AD. We investigated factors contributing to the cognitive improvement effects of acupuncture to obtain data for developing optimized acupuncture treatments for MCI.

Methods

This outcome assessor-blinded, randomized controlled trial included a full analysis for comparing the efficacy of different acupuncture methods. Thirty-two participants with MCI (i.e., fulfilling the Peterson diagnostic criteria for MCI, K-MMSE scores of 20–23, and MoCA-K scale scores of 0–22) were randomly assigned to basic acupuncture (BA; GV20, EX-HN1, GB20, and GV24 for 30 min), acupoint specificity (AS; adding KI3 to BA), needle duration (ND; BA for 20 min), or electroacupuncture (EA; electrical stimulation to BA) groups (n=8/group) via 1:1:1:1 allocation and administered acupuncture once daily, three times a week for 8 weeks. The measured outcomes included scores on the Korean version of the Alzheimer’s Disease Assessment Scale-cognitive subscale (ADAS-K-cog), Korean version of the Montreal Cognitive Assessment scale (MoCA-K), Center for Epidemiological Studies-Depression Scale, Korean Activities of Daily Living scale, Korean Instrumental Activities of Daily Living scale, and European Quality of Life Five Dimension Five Level Scale. Outcome measurements were recorded at baseline (week 0), intervention endpoint (week 8), and 12 weeks after intervention completion (week 20).

Results

Twenty-five patients with MCI completed the trial (BA group, 8; AS group, 6; ND group, 5; EA group, 6). MoCA-K scores were significantly increased in the BA group compared with the ND (p=0.008, week 8–week 0) and EA groups (p=0.003, week 8–week 0; p=0.043, week 20–week 0). ADAS-K-cog scores were significantly decreased in the BA group compared with the ND group (p=0.019, week 20–week 0).

Conclusions

The BA group showed significant improvement in cognitive function compared to the ND and EA groups. Electrical stimulation and needle duration may contribute to the cognitive improvement effects of acupuncture in patients with MCI.

Trial registration

Clinical Research Information Service; URL:cris.nih.go.kr.; unique identifier: KCT0003430 (registration date: January 16, 2019).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05296-4.

Efficacy of Tai Chi-Style Multi-Component Exercise on Frontal-Related Cognition and Physical Health in Elderly With Amnestic Mild Cognitive Impairment

Early prevention from accelerated neurocognitive declines with advanced aging and the delay of the onset of dementia have became paramount for the achievement of active aging. The present study examined whether the proposed non-pharmaceutical, multi-component exercise training which combined Tai-Chi exercise, Aerobic fitness, and thera-band therapy protects against age-related neurocognitive and physical deterioration in the older participants with amnestic mild cognitive impairment (aMCI). Participants with aMCI in the quasi-experimental design were assigned to the multi-component exercise group or care control group. Evaluations of neuropsychological function and functional fitness were performed before and after 12-weeks intervention, and after 24-weeks follow-up. Our results showed that the multi-component intervention significantly improved various domains of neurocognitive function, particularly in memory- and frontal-related cognition, and better performance on functional fitness, including muscle strength, cardiopulmonary endurance, and agility. Furthermore, such beneficial effects were preserved after 24 weeks. The findings provide supportive evidence that non-pharmaceutically multi-component intervention with Tai-Chi style practice as a core exercise may protect against age-related neurocognitive and physical deficits and lay the path on developing age-friendly intervention programs to delay, or even reverse, the progression of MCI to dementia.

Role of Executive Functions in the Conversion from Mild Cognitive Impairment to Dementia

Background: Recent research pointed to executive dysfunction as a potential early predictor of the progression of mild cognitive impairment (MCI) to dementia in Alzheimer’s clinical syndrome (ACS). Such cognitive impairments account for functional impairments in instrumental activities of daily living (IADL). Objective: The present study analyzes the contributions of executive functions to predict MCI–dementia progression in ACS. Methods: We assessed 145 participants, 51 cognitively unimpaired and 94 MCI. The latter were divided using the traditional, memory-based MCI classification (single domain amnestic, multidomain amnestic, and non-amnestic). Eight tests assessing executive functions were administered at baseline and at 1-year follow-up, together with cognitive screening tools and IADL measures. MCI patients were reclassified based on the outcomes from a K-mean cluster analysis which identified three groups. A simple lineal regression model was used to examine whether the classification based on executive functioning could more accurately predict progression to dementia a year later. Results: Clusters based on executive function deficits explained a significant proportion of the variance linked to MCI–dementia conversion, even after controlling for the severity of MCI at baseline (F(1, 68) = 116.25, p = 0.000, R2 = 0.63). Classical memory-based MCI classification failed to predict such a conversion (F(1, 68) = 5.09, p = 0.955, R2 = 0.07). Switching, categories generation, and planning were the executive functions that best distinguished between MCI converters and stable. Conclusion: MCI with a dysexecutive phenotype significantly predicts conversion to dementia in ACS a year later. Switching abilities and verbal fluency (categories) must be evaluated in MCI patients to assess risk of future dementia.

Sex differences in dementia: on the potentially mediating effects of educational attainment and experiences of psychological distress

BACKGROUND

Old-age dementias are known to disproportionally affect women as well as individuals with low educational attainment. The higher lifetime risk of dementia among women is usually attributed to their longer life expectancy. However, the impact of sex, and subsequent gender inequity, is likely to be more multifaceted than this explanation implies. Not least because of historical inequities in access to education between the sexes and the gender and socio-economic gradients in risk factors such as stress, depression and social isolation. Consequently, the present study sought to test whether differences in educational attainment and experiences of general psychological distress mediate the association between female sex and dementia.

METHODS

The study utilizes data obtained through the Gothenburg H70 Birth Cohort Study and the Prospective Populations Study on Women (n = 892). Data were analysed using Confirmatory Factor Analysis (CFA) and Structural Equation Modelling (SEM) with Weighted Least Squares Means and Variance adjusted (WLSMV) estimation. General psychological distress was indicated by a latent variable and constructed from five manifest items (previous depression, stress, self-esteem, chronic loneliness and satisfaction with social situation) that were all measured at baseline.

RESULTS

While the results could not corroborate that education directly mediates the effect of sex on dementia, level of distress was predicted by both female sex (0.607, p < .001) and education (- 0.166, p < .01) and, in turn, shown to be significantly associated with dementia (0.167, p < .05), also after controlling for confounders. When time from baseline to diagnosis was increased through sequential exclusion of dementia cases, the effect of distress on dementia was no longer significant.

CONCLUSION

The overall findings suggest that social (dis) advantage predicts general psychological distress, which thereby constitutes a potential, and rarely acknowledged, pathway between female sex, education, and dementia. They further underline the importance of attending to both education and distress as 'gendered' phenomena when considering the nature of their associations with dementia. However, the possibility of reverse causality bias must be acknowledged and the need for longitudinal studies with longer follow-up stressed.

Cost-effectiveness of a non-pharmacological treatment vs. "care as usual" in day care centers for community-dwelling older people with cognitive impairment: results from the German randomized controlled DeTaMAKS-trial

BACKGROUND

Cognitive impairment in older adults causes a high economic and societal burden. This study assesses the cost-effectiveness of the multicomponent, non-pharmacological MAKS treatment vs. "care as usual" in German day care centers (DCCs) for community-dwelling people with mild cognitive impairment (MCI) or mild to moderate dementia over 6 months.

METHODS

The analysis was conducted from the societal perspective alongside the cluster-randomized controlled, multicenter, prospective DeTaMAKS-trial with waitlist group design. Outcomes were Mini-Mental Status Examination (MMSE) and Erlangen Test of Activities of Daily Living in Persons with Mild Dementia or Mild Cognitive Impairment (ETAM) of 433 individuals in 32 DCCs. Incremental differences in MMSE and ETAM were calculated via a Gaussian-distributed and incremental cost difference via a Gamma-distributed Generalized Linear Model. Cost-effectiveness was assessed via cost-effectiveness planes and cost-effectiveness acceptability curves (CEAC).

RESULTS

At 6 months, MMSE (adjusted mean difference = 0.92; 95% confidence interval (CI): 0.17 to 1.67; p = 0.02) and ETAM (adjusted mean difference = 1.00; CI: 0.14 to 1.85; p = 0.02) were significantly better in the intervention group. The adjusted cost difference was - €938.50 (CI: - 2733.65 to 763.13; p = 0.31). Given the CEAC, MAKS was cost-effective for 78.0% of MMSE and 77.4% for ETAM without a need for additional costs to payers.

CONCLUSIONS

MAKS is a cost-effective treatment to stabilize the ability to perform activities of daily living and cognitive abilities of people with MCI or mild to moderate dementia in German DCCs. Thus, MAKS should be implemented in DCCs.

The Effects of Opioids on Cognition in Older Adults With Cancer and Chronic Noncancer Pain: A Systematic Review

CONTEXT

Opioids are prescribed to manage moderate-to-severe pain and can be used with older adults; however, they may lead to several adverse effects, including cognitive impairment.

OBJECTIVES

To identify, appraise, and synthesize evidence on the impact of opioids on cognition in older adults with cancer/chronic noncancer pain, and screening tools/neuropsychological assessments used to detect opioid-induced cognitive impairment.

METHODS

A systematic literature review following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (international prospective register of systematic reviews registration: CRD42018092943). MEDLINE, EMBASE, PsycINFO, CINAHL, Cochrane Library, and Web of Science were searched up to December 2018. Randomized controlled trials, quasi-experimental studies, and observational studies of adults aged 65 years and older with cancer/chronic noncancer pain taking opioids were included. A narrative synthesis was conducted.

RESULTS

From 4036 records, 10 met inclusion criteria. Five studies used one screening tool, and five studies used a range of neuropsychological assessments; assessing 14 cognitive domains. Most studies demonstrated no effect of opioid use on cognitive domains, whereas four studies showed mixed effects. In particular, attention, language, orientation, psychomotor function, and verbal working/delayed episodic memory were worsened. Changes to cognitive function were predominantly observed in studies with higher mean doses of opioids (120-190.7mg oral morphine equivalent daily dose).

CONCLUSION

Both improvements and impairments to cognition were observed in studies with higher mean opioid doses. In clinical practice, a brief screening tool assessing attention, language, orientation, psychomotor function, and verbal working/delayed episodic memory may be beneficial to detect worsening cognition in older adults with chronic pain using opioids.

Autonomic Nervous System and Cognitive Impairment in Older Patients: Evidence From Long-Term Heart Rate Variability in Real-Life Setting

Background: In geriatric age, cognitive impairment and cardiovascular disorders are frequent comorbidities. Age-related anatomical and functional cardiac changes, including the autonomic system, could interfere with the control of different cognitive domains. Therefore, we assess the relationship between long-term heart rate variability (HRV), as a measure of autonomic nervous system (ANS) functioning, and cognitive performance in elderly patients representative of outpatients in a real-life setting.

Methods: Of 155 elderly outpatients (aged >65 years) screened, 117 enrolled patients underwent anthropometric evaluation, cardiac assessment by 12-lead electrocardiogram, 24-h ECG recording, and blood pressure (BP) measurement, as well as global cognitive evaluation by a standardized multidimensional assessment, including the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment test (MoCA). HRV analysis was performed on 24-h ECG recordings focusing on time-domain indices [Standard deviation of the NN intervals (SDNN), standard deviations of 5-min mean values of the NN intervals for each 5-min interval (SDANN), and root mean squares of successive differences of the NN intervals (RMSSD)] and on frequency-domain measurements [heart rate (HR), low frequency (LF), high frequency (HF), and LF/HF]. Multivariate linear analysis was used to explore the influence of the HRV significant variables on MMSE and MoCA test values.

Results: The MMSE and MoCA scores were both significantly and positively correlated with the sympathetic system parameters (SDNN, SDANN, LF, and LF/HF ratio), but not with the parasympathetic system parameters (RMSSD and HF). Multivariate analysis confirms this relationship.

Conclusions: Our results show that, in a representative real-life community elderly population, an increased sympathetic activity, but not decreased vagal activity, is associated with better cognitive performances. These results support the sympathetic autonomic function, in that the relationship between better cognitive performances and a moderate prevalence of autonomic function appears dependent on long-term changes in heart rate, mediated by sympathetic activation.

Age- and education-adjusted normative data for the Rivermead Behavioural Memory Test (RBMT)

The original Rivermead Behavioural Memory Test (RBMT) suggests a cutoff global score of 10 points. However, this limit may be too stringent for older adults attending memory training programs, particularly for those with low education levels. This study aims to provide appropriately adjusted age and education norms for the RBMT. Data from 711 subjects were grouped based on age (65-67, 68-71, 72-75 and 76-83) and education level (primary school, high school and university studies). The data exhibit a clear trend of scores decreasing with age. The diminution in scores does not reach trend levels of significance between neighboring (< 5 years) age intervals, but it is statistically significant at the designated alpha level (p = .05) when younger and older adults are compared over a range of 5 years of difference. 81.86% of our sample has global scores below the suggested cutoff of 10 points. The present study provides a more accurate representation of RBMT global score performance in older adults for specific age and education stratifications.

Psychometric validation of Fuld Object Memory Evaluation in older adults with cognitive impairments

OBJECTIVES

Mild cognitive impairment (MCI) refers to an early but abnormal state of cognitive impairment with minimal functional impairment. The present study aimed to evaluate the validity of Fuld Object Memory Evaluation (FOME) as a measure of episodic memory function.

METHOD

The study sample included 204 Chinese older adults with cognitive impairments. The participants completed five recall trials and a delayed trial in FOME, neurocognitive measures on digit spans and trail making, and daily functioning. Discriminative power of FOME to differentiate between MCI and dementia was inspected via receiver operating characteristic curve analysis.

RESULTS

FOME showed good test-retest reliability and convergent validity with digit spans and trail making. Controlling for gender, age, and education, lower levels of FOME total retrieval, verbal fluency, and daily functioning significantly predicted a higher likelihood of dementia compared to MCI. The optimal cut-off scores for total retrieval, verbal fluency, and daily functioning to differentiate dementia were 37/38 (77% sensitivity and 83% specificity), 28/29 (85% sensitivity and 72% specificity), and 14/15 (92% sensitivity and 78% specificity), respectively, in the younger subgroup. The corresponding figures were 34/35 (69% sensitivity and 76% specificity) and 27/28 (92% sensitivity and 62% specificity), and 11/12 (74% sensitivity and 80% specificity), respectively, in the older subgroup.

CONCLUSION

The findings support the FOME as a valid assessment tool of episodic memory function in older Chinese adults. The combined use of FOME and daily functioning is recommended to distinguish persons with dementia from MCI.

Computerised cognitive training for preventing dementia in people with mild cognitive impairment

BACKGROUND

The number of people living with dementia is increasing rapidly. Clinical dementia does not develop suddenly, but rather is preceded by a period of cognitive decline beyond normal age-related change. People at this intermediate stage between normal cognitive function and clinical dementia are often described as having mild cognitive impairment (MCI). Considerable research and clinical efforts have been directed toward finding disease-modifying interventions that may prevent or delay progression from MCI to clinical dementia.

OBJECTIVES

To evaluate the effects of at least 12 weeks of computerised cognitive training (CCT) on maintaining or improving cognitive function and preventing dementia in people with mild cognitive impairment.

SEARCH METHODS

We searched to 31 May 2018 in ALOIS (www.medicine.ox.ac.uk/alois) and ran additional searches in MEDLINE, Embase, PsycINFO, CINAHL, ClinicalTrials.gov, and the WHO portal/ICTRP (www.apps.who.int/trialsearch) to identify published, unpublished, and ongoing trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs in which cognitive training via interactive computerised technology was compared with an active or inactive control intervention. Experimental computerised cognitive training (CCT) interventions had to adhere to the following criteria: minimum intervention duration of 12 weeks; any form of interactive computerised cognitive training, including computer exercises, computer games, mobile devices, gaming console, and virtual reality. Participants were adults with a diagnosis of mild cognitive impairment (MCI) or mild neurocognitive disorder (MND), or otherwise at high risk of cognitive decline.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias of the included RCTs. We expressed treatment effects as mean differences (MDs) or standardised mean differences (SMDs) for continuous outcomes and as risk ratios (RRs) for dichotomous outcomes. We used the GRADE approach to describe the overall quality of evidence for each outcome.

MAIN RESULTS

Eight RCTs with a total of 660 participants met review inclusion criteria. Duration of the included trials varied from 12 weeks to 18 months. Only one trial used an inactive control. Most studies were at unclear or high risk of bias in several domains. Overall, our ability to draw conclusions was hampered by very low-quality evidence. Almost all results were very imprecise; there were also problems related to risk of bias, inconsistency between trials, and indirectness of the evidence.No trial provided data on incident dementia. For comparisons of CCT with both active and inactive controls, the quality of evidence on our other primary outcome of global cognitive function immediately after the intervention period was very low. Therefore, we were unable to draw any conclusions about this outcome.Due to very low quality of evidence, we were also unable to determine whether there was any effect of CCT compared to active control on our secondary outcomes of episodic memory, working memory, executive function, depression, functional performance, and mortality. We found low-quality evidence suggesting that there is probably no effect on speed of processing (SMD 0.20, 95% confidence interval (CI) -0.16 to 0.56; 2 studies; 119 participants), verbal fluency (SMD -0.16, 95% CI -0.76 to 0.44; 3 studies; 150 participants), or quality of life (mean difference (MD) 0.40, 95% CI -1.85 to 2.65; 1 study; 19 participants).When CCT was compared with inactive control, we obtained data on five secondary outcomes, including episodic memory, executive function, verbal fluency, depression, and functional performance. We found very low-quality evidence; therefore, we were unable to draw any conclusions about these outcomes.

AUTHORS' CONCLUSIONS

Currently available evidence does not allow us to determine whether or not computerised cognitive training will prevent clinical dementia or improve or maintain cognitive function in those who already have evidence of cognitive impairment. Small numbers of trials, small samples, risk of bias, inconsistency between trials, and highly imprecise results mean that it is not possible to derive any implications for clinical practice, despite some observed large effect sizes from individual studies. Direct adverse events are unlikely to occur, although the time and sometimes the money involved in computerised cognitive training programmes may represent significant burdens. Further research is necessary and should concentrate on improving methodological rigour, selecting suitable outcomes measures, and assessing generalisability and persistence of any effects. Trials with long-term follow-up are needed to determine the potential of this intervention to reduce the risk of dementia.

Cognitive tests for the detection of mild cognitive impairment (MCI), the prodromal stage of dementia: Meta-analysis of diagnostic accuracy studies

INTRODUCTION

Mild cognitive impairment (MCI) is regarded as a prodrome to dementia. Various cognitive tests can help with diagnosis; meta-analysis of diagnostic accuracy studies would assist clinicians in choosing optimal tests.

METHODS

We searched online databases for "mild cognitive impairment" and "diagnosis" or "screening" from 01/01/1999 to 01/07/2017. Articles assessing the diagnostic accuracy of a cognitive test compared with standard diagnostic criteria were extracted. Risk of bias was assessed. Bivariate random-effects meta-analysis was used to evaluate sensitivity and specificity.

RESULTS

Eight cognitive tests (ACE-R, CERAD, CDT-Sunderland, IQCODE, Memory Alteration Test, MMSE, MoCA, and Qmci) were considered for meta-analysis. ACE-R, CERAD, MoCA, and Qmci were found to have similar diagnostic accuracy, while the MMSE had lower sensitivity. Memory Alteration Test had the highest sensitivity and equivalent specificity to the other tests.

DISCUSSION

Multiple cognitive tests have comparable diagnostic accuracy. The Memory Alteration Test is short and has the highest sensitivity. New cognitive tests for MCI diagnosis should not be compared with the MMSE.

Experimental effects of exercise on memory function among mild cognitive impairment: systematic review and meta-analysis

OBJECTIVE

The objective of this study was to evaluate the experimental effects of exercise on memory function among adults with mild cognitive impairment (MCI).

METHODS

A systematic review and meta-analysis were employed. Studies were identified using electronic databases, including PubMed, PsychInfo, SPORTDiscus, and Google Scholar. To be eligible for inclusion, studies had to employ an experimental design, be conducted in humans (no animal models) with mild cognitive impairment, include an exercise intervention arm (either acute exercise or chronic training), and measure memory function (any type) as the outcome measure. Comprehensive Meta-Analysis software was used to compute the standardized mean difference effect size (Cohen's d) and 95% CI using a random-effects model.

RESULTS

In total, 11 studies met our criteria, contributing to 20 effect size estimates. Among the 20 effect size estimates, 13 contributed to a short-term memory recall, with 7 contributing to a delayed/long-term memory recall. The overall weighted mean effect size was d = 0.30 (95% CI: 0.16-0.44; P < 0.001), indicating a small to medium effect of exercise on improving memory function. For the moderation analysis, there was no evidence of a moderation effect for recall duration (Q = 0.004, df(1), P = 0.95), as exercise (vs. control) demonstrated both short-term (d = 0.31; 95% CI: 0.14-0.47; P < 0.001) and long-term memory (d = 0.29; 95% CI: 0.06-0.53; P = 0.013) benefits.

CONCLUSION

Current evidence suggests that exercise may help to improve memory function among those with MCI. Safe and progressive forms of exercise should be promoted among MCI patients.

Vitamin and mineral supplementation for maintaining cognitive function in cognitively healthy people in mid and late life

BACKGROUND

Vitamins and minerals play multiple functions within the central nervous system which may help to maintain brain health and optimal cognitive functioning. Supplementation of the diet with various vitamins and minerals has been suggested as a means of maintaining cognitive function, or even of preventing dementia, in later life.

OBJECTIVES

To evaluate the effects of vitamin and mineral supplementation on cognitive function in cognitively healthy people aged 40 years or more.

SEARCH METHODS

We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group's (CDCIG) specialised register, as well as MEDLINE, Embase, PsycINFO, CINAHL, ClinicalTrials.gov and the WHO Portal/ICTRP from inception to 26th January 2018.

SELECTION CRITERIA

We included randomised controlled trials that evaluated the cognitive effects on people aged 40 years or more of any vitamin or mineral supplements taken by mouth for at least three months.

DATA COLLECTION AND ANALYSIS

Study selection, data extraction, and quality assessments were done in duplicate. Vitamins were considered broadly in the categories of B vitamins, antioxidant vitamins, and combinations of both. Minerals were considered separately, where possible. If interventions and outcomes were considered sufficiently similar, then data were pooled. In order to separate short-term cognitive effects from possible longer-term effects on the trajectory of cognitive decline, data were pooled for various treatment durations from 3 months to 12 months and up to 10 years or more.

MAIN RESULTS

In total, we included 28 studies with more than 83,000 participants. There were some general limitations of the evidence. Most participants were enrolled in studies which were not designed primarily to assess cognition. These studies often had no baseline cognitive assessment and used only brief cognitive assessments at follow-up. Very few studies assessed the incidence of dementia. Most study reports did not mention adverse events or made only very general statements about them. Only 10 studies had a mean follow-up > 5 years. Only two studies had participants whose mean age was < 60 years at baseline. The risk of bias in the included studies was generally low, other than a risk of attrition bias for longer-term outcomes. We considered the certainty of the evidence behind almost all results to be moderate or low.We included 14 studies with 27,882 participants which compared folic acid, vitamin B12, vitamin B6, or a combination of these to placebo. The majority of participants were aged over 60 years and had a history of cardio- or cerebrovascular disease. We found that giving B vitamin supplements to cognitively healthy adults, mainly in their 60s and 70s, probably has little or no effect on global cognitive function at any time point up to 5 years (SMD values from -0.03 to 0.06) and may also have no effect at 5-10 years (SMD -0.01). There were very sparse data on adverse effects or on incidence of cognitive impairment or dementia.We included 8 studies with 47,840 participants in which the active intervention was one or more of the antioxidant vitamins: ß-carotene, vitamin C or vitamin E. Results were mixed. For overall cognitive function, there was low-certainty evidence of benefit associated with ß-carotene after a mean of 18 years of treatment (MD 0.18 TICS points, 95% CI 0.01 to 0.35) and of vitamin C after 5 years to 10 years (MD 0.46 TICS points, 95% CI 0.14 to 0.78), but not at earlier time points. From two studies which reported on dementia incidence, there was low-certainty evidence of no effect of an antioxidant vitamin combination or of vitamin E, either alone or combined with selenium. One of the included studies had been designed to look for effects on the incidence of prostate cancer; it found a statistically significant increase in prostate cancer diagnoses among men taking vitamin E.One trial with 4143 participants compared vitamin D3 (400 IU/day) and calcium supplements to placebo. We found low- to moderate-certainty evidence of no effect of vitamin D3 and calcium supplements at any time-point up to 10 years on overall cognitive function (MD after a mean of 7.8 years -0.1 MMSE points, 95% CI -0.81 to 0.61) or the incidence of dementia (HR 0.94, 95% CI 0.72 to 1.24). A pilot study with 60 participants used a higher dose of vitamin D3 (4000 IU on alternate days) and found preliminary evidence that this dose probably has no effect on cognitive function over six months.We included data from one trial of zinc and copper supplementation with 1072 participants. There was moderate-certainty evidence of little or no effect on overall cognitive function (MD 0.6 MMSE points, 95% CI -0.19 to 1.39) or on the incidence of cognitive impairment after 5 years to 10 years. A second smaller trial provided no usable data, but reported no cognitive effects of six months of supplementation with zinc gluconate.From one study with 3711 participants, there was low-certainty evidence of no effect of approximately five years of selenium supplementation on the incidence of dementia (HR 0.83, 95% CI 0.61 to 1.13).Finally, we included three trials of complex supplements (combinations of B vitamins, antioxidant vitamins, and minerals) with 6306 participants. From the one trial which assessed overall cognitive function, there was low-certainty evidence of little or no effect on the TICS (MD after a mean of 8.5 years 0.12, 95% CI -0.14 to 0.38).

AUTHORS' CONCLUSIONS

We did not find evidence that any vitamin or mineral supplementation strategy for cognitively healthy adults in mid or late life has a meaningful effect on cognitive decline or dementia, although the evidence does not permit definitive conclusions. There were very few data on supplementation starting in midlife (< 60 years); studies designed to assess cognitive outcomes tended to be too short to assess maintenance of cognitive function; longer studies often had other primary outcomes and used cognitive measures which may have lacked sensitivity. The only positive signals of effect came from studies of long-term supplementation with antioxidant vitamins. These may be the most promising for further research.

Vitamin and mineral supplementation for preventing dementia or delaying cognitive decline in people with mild cognitive impairment

BACKGROUND

Vitamins and minerals have many functions in the nervous system which are important for brain health. It has been suggested that various different vitamin and mineral supplements might be useful in maintaining cognitive function and delaying the onset of dementia. In this review, we sought to examine the evidence for this in people who already had mild cognitive impairment (MCI).

OBJECTIVES

To evaluate the effects of vitamin and mineral supplementation on cognitive function and the incidence of dementia in people with mild cognitive impairment.

SEARCH METHODS

We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group's (CDCIG) specialised register, as well as MEDLINE, Embase, PsycINFO, CENTRAL, CINAHL, LILACs, Web of Science Core Collection, ClinicalTrials.gov, and the WHO Portal/ICTRP, from inception to 25 January 2018.

SELECTION CRITERIA

We included randomised or quasi-randomised, placebo-controlled trials which evaluated orally administered vitamin or mineral supplements in participants with a diagnosis of mild cognitive impairment and which assessed the incidence of dementia or cognitive outcomes, or both. We were interested in studies applicable to the general population of older people and therefore excluded studies in which participants had severe vitamin or mineral deficiencies.

DATA COLLECTION AND ANALYSIS

We sought data on our primary outcomes of dementia incidence and overall cognitive function and on secondary outcomes of episodic memory, executive function, speed of processing, quality of life, functional performance, clinical global impression, adverse events, and mortality. We conducted data collection and analysis according to standard Cochrane systematic review methods. We assessed the risk of bias of included studies using the Cochrane 'Risk of bias' assessment tool. We grouped vitamins and minerals according to their putative mechanism of action and, where we considered it to be clinically appropriate, we pooled data using random-effects methods. We used GRADE methods to assess the overall quality of evidence for each comparison and outcome.

MAIN RESULTS

We included five trials with 879 participants which investigated B vitamin supplements. In four trials, the intervention was a combination of vitamins B6, B12, and folic acid; in one, it was folic acid only. Doses varied. We considered there to be some risks of performance and attrition bias and of selective outcome reporting among these trials. Our primary efficacy outcomes were the incidence of dementia and scores on measures of overall cognitive function. None of the trials reported the incidence of dementia and the evidence on overall cognitive function was of very low-quality. There was probably little or no effect of B vitamins taken for six to 24 months on episodic memory, executive function, speed of processing, or quality of life. The evidence on our other secondary clinical outcomes, including harms, was very sparse or very low-quality. There was evidence from one study that there may be a slower rate of brain atrophy over two years in participants taking B vitamins. The same study reported subgroup analyses based on the level of serum homocysteine (tHcy) at baseline and found evidence that B vitamins may improve episodic memory in those with tHcy above the median at baseline.We included one trial (n = 516) of vitamin E supplementation. Vitamin E was given as 1000 IU of alpha-tocopherol twice daily. We considered this trial to be at risk of attrition and selective reporting bias. There was probably no effect of vitamin E on the probability of progression from MCI to Alzheimer's dementia over three years (HR 1.02; 95% CI 0.74 to 1.41; n = 516; 1 study, moderate-quality evidence). There was also no evidence of an effect at intermediate time points. The available data did not allow us to conduct analyses, but the authors reported no significant effect of three years of supplementation with vitamin E on overall cognitive function, episodic memory, speed of processing, clinical global impression, functional performance, adverse events, or mortality (five deaths in each group). We considered this to be low-quality evidence.We included one trial (n = 256) of combined vitamin E and vitamin C supplementation and one trial (n = 26) of supplementation with chromium picolinate. In both cases, there was a single eligible cognitive outcome, but we considered the evidence to be very low-quality and so could not be sure of any effects.

AUTHORS' CONCLUSIONS

The evidence on vitamin and mineral supplements as treatments for MCI is very limited. Three years of treatment with high-dose vitamin E probably does not reduce the risk of progression to dementia, but we have no data on this outcome for other supplements. Only B vitamins have been assessed in more than one RCT. There is no evidence for beneficial effects on cognition of supplementation with B vitamins for six to 24 months. Evidence from a single study of a reduced rate of brain atrophy in participants taking vitamin B and a beneficial effect of vitamin B on episodic memory in those with higher tHcy at baseline warrants attempted replication.

Encoding deficits in low-educated individuals with non-amnestic Mild Cognitive Impairment. Analysis of memory processes using the Item Specific Deficit Approach

This work aims to analyze encoding impairments using new assessment scores in patients with naMCI who present to memory clinics with subjective cognitive complaints. The sample included 102 participants, of whom 28 were classified as healthy controls (HC), 24 as amnestic MCI (aMCI), 24 as naMCI and 26 patients as Alzheimer's disease (AD). Research outcomes were the Encoding, Consolidation and Retrieval deficit indices from the Item Specific Deficit Approach, and traditional indices (immediate total recall, delayed cued recall, delayed total recall) derived from the Free and Cued Selective Reminding Test (FCSRT). We found no differences in immediate recall or delayed recall between HC and naMCI on the FCSRT, both scoring higher than aMCI and AD. naMCI showed encoding deficits in between HC and aMCI, with no differences between naMCI and HC on consolidation or retrieval deficit indices. The ISDA indices were better than traditional indices to discriminate between HC and naMCI (sensitivity: 70.8%, specificity: 78.6%), whereas the opposite pattern was found between naMCI and aMCI (sensitivity: 70.8%, specificity: 91.7%). New indices derived from neuropsychological tests may help to identify objective memory impairments in naMCI. Whether these new indices are useful for predicting conversion to AD needs further research.

Sex differences in the prevalence and incidence of mild cognitive impairment: A meta-analysis

OBJECTIVE

More women have Alzheimer's disease (AD) than men. Understanding sex differences in mild cognitive impairment (MCI) may further knowledge of AD etiology and prevention. We conducted a meta-analysis to examine sex differences in the prevalence and incidence of MCI, which included amnestic and non-amnestic subtypes.

METHOD

Systematic searches were performed in July 2015 using MEDLINE/PubMed, Scopus, and PsycINFO for population-or community-based studies with MCI data for men and women. Random-effects model were used.

RESULTS

Fifty-six studies were included. There were no statistically significant sex differences in prevalence or incidence of amnestic MCI. There was a significantly higher prevalence (p=0.038), but not incidence, of non-amnestic MCI among women. There were no sex differences in studies that combined both subtypes of MCI.

CONCLUSION

The only statistically significant finding emerging from this study was that women have a higher prevalence of non-amnestic MCI. To better understand sex differences in the preclinical stages of dementia, studies must better characterize the etiology of the cognitive impairment.

Predictors of Medication Adherence in the Elderly: The Role of Mental Health

The aging population routinely has comorbid conditions requiring complicated medication regimens, yet nonadherence can preclude optimal outcomes. This study explored the association of adherence in the elderly with demographic, socioeconomic, and disease burden measures. Data were from the fifth visit (2011-2013) for 6,538 participants in the Atherosclerosis Risk in Communities Study, conducted in four communities. The Morisky-Green-Levine Scale measured self-reported adherence. Forty percent of respondents indicated some nonadherence, primarily due to poor memory. Logit regression showed, surprisingly, that persons with low reading ability were more likely to report being adherent. Better self-reported physical or mental health both predicted better adherence, but the magnitude of the association was greater for mental than for physical health. Compared with persons with normal or severely impaired cognition, mild cognitive impairment was associated with lower adherence. Attention to mental health measures in clinical settings could provide opportunities for improving medication adherence.

Mismatch negativity as a potential neurobiological marker of early-stage Alzheimer disease and vascular dementia

Alzheimer's disease (AD) and vascular dementia (VD) are serious, irreversible forms of cognitive impairment, which means that an early diagnosis is essential to slow down their progression. One potential neurophysiological biomarker of these diseases is the mismatch negativity (MMN) event-related potentials (ERP) component, which reflects an automatic detection mechanism at the pre-attentive stages of information processing. We evaluated the auditory MMN response in individuals from two patient groups: those in the prodromal stages of AD (P-AD) and those in the prodromal stages of VD (P-VD). Thirty patients (15 P-AD patients and 15 P-VD patients) and 30 age-matched controls were recruited to undergo electrophysiological recordings during the presentation of an auditory deviant-standard-reverse oddball paradigm that was used to elicit genuine MMN responses. We show that over the frontal-central area, the mean amplitude of the MMN was significantly reduced in both the P-AD (p=0.017) and P-VD groups (p=0.013) compared with controls. The MMN peak latency in P-VD patients was significantly shorter than in controls (p=0.027). No MMN response differences between the P-AD and P-VD were found in either the frontal-central or the temporal areas. These results indicate that P-AD and P-VD patients exhibit impaired pre-attentive information processing mechanisms as revealed by the frontal-central area MMN response, which is associated with sensory memory and cognitive deficits.

Associations of cumulative Pb exposure and longitudinal changes in Mini-Mental Status Exam scores, global cognition and domains of cognition: The VA Normative Aging Study

BACKGROUND

Lead (Pb) exposure has been associated with poorer cognitive function cross-sectionally in aging adults, however the association between cumulative Pb exposure and longitudinal changes in cognition is little characterized.

METHODS

In a 1993-2007 subcohort of the VA Normative Aging Study (Mini-mental status exam (MMSE) n=741; global cognition summary score n=715), we used linear mixed effects models to test associations between cumulative Pb exposure (patella or tibia bone Pb) and repeated measures of cognition (MMSE, individual cognitive tests, and global cognition summary). Cox proportional hazard modeling assessed the risk of an MMSE score falling below 25.

RESULTS

Among men 51-98 at baseline, higher patella Pb concentration (IQR: 21μg/g) was associated with -0.13 lower baseline MMSE (95% CI: -0.25, -0.004) and faster longitudinal MMSE decline (-0.016 units/year, 95% CI: -0.032, -0.0004) over 15 years. Each IQR increase in patella Pb was associated with increased risk of a MMSE score below 25 (HR=1.21, 95% CI: 0.99, 1.49; p=0.07). There were no significant associations between Pb and global cognition (both baseline and longitudinal change). Patella Pb was associated with faster longitudinal decline in Word List Total Recall in the language domain (0.014 units/year, 95% CI: -0.026, -0.001) and Word List Delayed Recall in the memory domain (0.014 units/year, 95% CI: -0.027, -0.002). We found weaker associations with tibia Pb.

CONCLUSIONS

Cumulative Pb exposure is associated with faster declines in MMSE and Word List Total and Delayed Recall tests. These findings support the hypothesis that Pb exposure accelerates cognitive aging.

Comorbid Depression and Diabetes as a Risk for Mild Cognitive Impairment and Alzheimer's Disease in Elderly Mexican Americans

BACKGROUND

The links between diabetes, depression, and Alzheimer's disease (AD) has been established, but they are still poorly understood. However, little research has examined the effect that comorbidity of depression and diabetes has on cognitive impairment in an ethnically diverse sample.

OBJECTIVE

The purpose of this study was to investigate the relationship between comorbid diabetes and depression on cognitive dysfunction; and examine the relationship in an ethnically diverse population.

METHODS AND RESULTS

Analyses of data from 2,436 participants (914 men and 1,522 women) of three separate cohorts: HABLE, FRONTIER, and TARCC. In the HABLE cohort, comorbidity (odds ratio [OR] = 3.008; 95% CI = 1.358-6.667), age (OR = 1.138; 95% CI = 1.093-1.185), and education (OR = 0.915; 95% CI = 0.852-0.982) increased the risk of mild cognitive impairment (MCI) diagnosis among elderly Mexican American. In the TARCC cohort, results showed an increase risk of MCI in both non-Hispanic whites (OR = 18.795; 95% CI = 2.229-158.485) and Mexican Americans (OR = 8.417; 95% CI = 2.967-23.878). Finally, results in the FRONTIER cohort showed that in elderly Mexican Americans, comorbidity (OR = 2.754; 95% CI = 1.084-6.995) and age (OR = 1.069; 95% CI = 1.023-1.118) significantly increased risk of MCI. In non-Hispanic whites, comorbidity did not significantly increase risk of MCI.

CONCLUSIONS

Among elderly Mexican Americans, comorbid depression and diabetes significantly increased risk for MCI and AD across cohorts. Effects of comorbid diabetes and depression on MCI were inconclusive. Our results support the link between comorbid diabetes and depression and risk for cognitive decline among Mexican Americans. This finding is of critical importance as the Hispanic population is at higher risk of developing AD.

Neuroprotective Effects of Electroacupuncture on an Animal Model of Bilateral Common Carotid Artery Occlusion

Mild cognitive impairment (MCI) is considered as an intermediate zone between normal aging and dementia. The most prominent feature of MCI is an isolated mild decline in memory, whereas other cognitive functions remain intact. The symptoms of vascular cognitive impairment (VCI) range from MCI to dementia, and an animal model of VCI has been established in a gerbil by transient bilateral common carotid artery occlusion (BCCAO). In the current study, we set out to investigate whether electroacupuncture (EA) could improve memory in gerbils with BCCAO-induced MCI. Animals were randomly divided into two groups: sham-operated group (n = 17) and a model group that was subdivided into BCCAO, n = 17, and EA-treated BCCAO, n = 28. Gerbils were treated with EA at KI3 or GV20 four times every other day using a set of electrical stimulus pulses (1 mA, 2 Hz) that were applied for 20 min. For investigation of cognitive function, we performed a Y-maze test and Western blotting to identify the expression of neuroinflammatory proteins. EA treatment at KI3 ("Taegye" acupoint) improved cognitive function and reduced the expression of neuroinflammatory proteins including ionized calcium-binding adaptor molecule 1, toll-like receptor 4, tumor necrosis factor alpha, and phospho-extracellular signal-regulated kinase in the hippocampus of gerbils that had undergone BCCAO. Furthermore, using micro-positron emission tomography/computed tomography, we demonstrated that EA treatment increased glucose metabolism in the hippocampus of these animals. The present study highlights the neuroprotective effect of EA treatment against BCCAO-induced memory dysfunction, neuroinflammation, and glucose metabolism. Our findings suggest that EA, which has previously been used in complementary and alternative medicine, might also be considered as a therapy that can improve memory and reduce neuroinflammation associated with dementia.