Mild cognitive impairment: diagnosis, longitudinal course, and emerging treatments

Efficacy and Safety of Exogenous Ketones in People with Mild Neurocognitive Disorder and Alzheimer's Disease: A Systematic Literature Review

CONTEXT

Mild neurocognitive disorder (NCD), formally known as mild cognitive impairment, is usually the clinical stage preceding the development of Alzheimer's disease (AD), the most prevalent major NCD, and other causes of dementia. Glucose is a major source of energy for human brain metabolism and the uptake of glucose is reduced in patients with mild NCD, AD, and other NCDs. Unlike glucose, the uptake of ketones remains normal in people with mild NCD and AD, suggesting that the use of ketone bodies may compensate for glucose energy deficiency in patients with mild NCD and AD.

OBJECTIVE

The aim of this systematic review was to summarize the efficacy and safety of exogenic ketones, including medium chain triglycerides (MCTs), on cognitive function in patients with mild NCD and AD.

DATA SOURCES

The Embase, MEDLINE, MEDLINE In-Process, PubMed Ahead-of-Print, Cochrane Central Register of Controlled Trials, Europe PMC databases were searched from inception to April 2022. Studies reporting cognitive function efficacy and safety outcomes from randomized controlled trials of exogenic ketones in patients with mild NCD and AD were included.

DATA EXTRACTION

Data were extracted by 1 reviewer and checked by a second reviewer. Risk of bias was assessed using the Cochrane risk of bias tool, version 2.

DATA ANALYSIS

This review identified 13 individual trials investigating the efficacy and safety of MCT or coconut oil for patients with mild NCD or with AD. Because of the heterogeneity of the studies, a narrative synthesis was used.

CONCLUSION

Overall, improvements associated with exogenic ketones were observed in multiple aspects of cognitive abilities, although the large heterogeneity between the included studies makes it difficult to draw firm conclusions from the current literature. Although some studies investigated the impact of the apolipoprotein E ε4 allele status on treatment efficacy, the current data are insufficient to conclude whether such an effect is present.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration No. CRD42022336664.

The vulnerability of hip fracture patients with cognitive impairment: an analysis of health conditions, hospital care, and outcomes

BACKGROUND

Cognitive impairment, including dementia, and hip fracture are both common among older patients. Both conditions are associated with increased morbidity and mortality. Cognitive impairment is often underdiagnosed and may remain undetected in hip fracture patients. Little is known about the prevalence, specific characteristics, and outcomes of hip fracture patients with cognitive impairment. This analysis aimed to compare hip fracture patients with and without cognitive impairments regarding their health conditions, hospital care, and the risk of complications and mortality.

METHODS

This study used data derived from the EMAAge project, a prospective multi-center cohort study conducted in Berlin, Germany. Patients aged 40 years and older with hip fracture were stratified into three cognitive status groups: no cognitive impairment (NCI), moderate cognitive impairment (MCI), and severe cognitive impairment (SCI). Categorization was based on patients' ability to engage in interviews and their performance on the 6-item Cognitive Impairment Test (6-CIT). Standardized mean differences were used to compare various health-related parameters and health care utilization measures. Regression models, both adjusted and unadjusted, were calculated for the number of complications and the mortality rate.

RESULTS

Cognitive impairment was present in 37% of the 310 hip fracture patients in the study cohort. Patients with cognitive impairment had a worse baseline health profile, delayed admission to the emergency department, a longer time to surgery, and were less likely to be referred to a rehabilitation program. In the adjusted regression model for the number of complications, the incidence rate ratio was 1.237 (p = 0.292) for MCI patients and 2.065 (p < 0.001) for SCI patients compared with NCI patients. The adjusted odds ratio for mortality was 1.046 (p = 0.942) for MCI patients and 2.875 (p = 0.060) for SCI patients.

CONCLUSIONS

Hip fracture patients with cognitive impairment, particularly severe impairment, arrive at the ED in a considerably poorer state of health and are at a higher risk of adverse outcomes, including complications and mortality. Timely identification of this at-risk group upon arrival appears to be essential to providing adequate care. This study highlights the need for interventions and research aimed at improving prevention, emergency care and outcomes for this vulnerable group, addressing their specific risk factors, and promoting the quality of care in hospital and after discharge.

The Association Between Metabolic Score for Visceral Fat and Cognitive Function Among Older Adults in the United States

BACKGROUND

Although several studies have demonstrated a link between obesity and cognitive function, the majority have primarily utilized body mass index (BMI) and waist circumference, ignoring the distribution of body fat. Evidence regarding the association of metabolic score for visceral fat (METS-VF), a proposed measurement for visceral adipose tissue (VAT), with cognitive function remains limited. We mainly aimed to investigate this association in older adults in the United States.

METHODOLOGY

Data were from the National Health and Nutrition Examination Survey (NHANES) 2011 to 2014. Weighted linear regression models were adopted to examine the association of METS-VF and cognitive function scores, with further exploration of these associations across different obesity subgroups. Smoothing curve analysis, along with threshold and saturation effect analysis, were conducted to explore potential non-linear relationships.

RESULTS

In the multivariable-adjusted model, participants in the highest quartile (Quartile 4) of METS-VF exhibited a β coefficient of -1.52 [95% CI (-2.43, -0.62)] for the CERAD score compared with those in the lowest quartile (Quartile 1). Threshold and saturation effect analysis revealed non-linear associations of METS-VF with DSST score and Z-score.

CONCLUSIONS

The findings of this study indicate that elevated METS-VF scores are inversely related to cognitive function, highlighting the importance of considering visceral fat distribution in cognitive health assessments.

The effects of different types of exercises on cognition in older persons with mild cognitive impairment: A systematic review and meta-analysis

PURPOSE

This systematic review with meta-analysis aims to analyze the effects of different types of exercise on cognition, neuroprotective and neuroinflammatory blood markers in older adults with mild cognitive impairment (MCI).

METHODS

Relevant studies were identified using PubMED, SPORTDiscuss, Web of Science, Scopus, and PsycInfo databases. Methodological quality assessment of the studies was done with modified Downs and Black checklist. Data obtained from the included studies was analyzed using Comprehensive Meta-Analysis 4.0 software and results were reported using the random effects method.

RESULTS

A total of twenty-three studies were identified. The findings were summarized as change in cognitive function after the exercise interventions in general and after each type of exercise. On average, the exercise intervention revealed an effect size (ES): 1.165; 0.741 to 1.589 (95% Confidence Interval (CI); p < 0.001); aerobic exercise ES: 1.442; 0.624 to 2.260 (95 %CI); p = 0.001; Multimodal ES: 0,856; 0.366 to 1.346 (95 % CI); p = 0.001 and resistance exercise ES: 1.229; 0.339 to 2.120 (95 % CI); p = 0.007. In addition, we observed significant small ES: -0.475; -0.817 to -0.134 (95 %CI); p = 0.006, I2= 0 %; τ2 = 0 of exercise effects on Tumor Necrosis Factor-α (TNF-α) and non-significant large ES:0.952; -0.238 to 2.142 (95 %CI); p = 0.117 on Brain Derived Neurotrophic Factor (BDNF) in persons with MCI.

CONCLUSION

The present study revealed the existence of a large positive effect of overall exercise intervention on cognitive function and a small effect on TNF-α in old people with MCI. Additionally, this study demonstrates that aerobic and resistance exercises had similar larger positive effects and were better than multimodal exercise on increasing cognition in older persons with MCI.

Exploring cortical morphology biomarkers of amnesic mild cognitive impairment using novel fractal dimension-based structural MRI analysis

Amnestic mild cognitive impairment (aMCI) is considered as an intermediate stage of Alzheimer's disease, but no MRI biomarkers currently distinguish aMCI from healthy individuals effectively. Fractal dimension, a quantitative parameter, provides superior morphological information compared to conventional cortical thickness methods. Few studies have used cortical fractal dimension values to differentiate aMCI from healthy controls. In this study, we aim to build an automated discriminator for accurately distinguishing aMCI using fractal dimension measures of the cerebral cortex. Thirty aMCI patients and 30 health controls underwent structural MRI of the brain. First, the atrophy of participants' cortical sub-regions of Desikan-Killiany cortical atlas was assessed using fractal dimension and cortical thickness. The fractal dimension is more sensitive than cortical thickness in reducing dimensional effects and may accurately reflect morphological changes of the cortex in aMCI. The aMCI group had significantly lower fractal dimension values in the bilateral temporal lobes, right limbic lobe and right parietal lobe, whereas they showed significantly lower cortical thickness values only in the bilateral temporal lobes. Fractal dimension analysis was able to depict most of the significantly different focal regions detected by cortical thickness, but additionally with more regions. Second, applying the measured fractal dimensions (and cortical thickness) of both cerebral hemispheres, an unsupervised discriminator was built for the aMCI and healthy controls. The proposed fractal dimension-based method achieves 80.54% accuracy in discriminating aMCI from healthy controls. The fractal dimension appears to be a promising biomarker for cortical morphology changes that can discriminate patients with aMCI from healthy controls.

The Effect of Physical Exercise on Patients With Mild Cognitive Impairment: A Scoping Review

Mild cognitive impairment (MCI) is characterized by a noticeable decline in cognitive abilities that is not severe enough to significantly interfere with daily life or independent functioning. Recent research highlights the important role of exercise in managing and improving cognitive function in patients with MCI. This scoping review examines the benefits of different forms of exercise in improving cognitive function. Recommendations for exercise, including frequency, consistency, and individualized programs, are discussed in this review, with an emphasis on the importance of safety and regular monitoring. The integration of physical and cognitive training is also suggested to maximize benefits. Regular physical exercise is a promising intervention for mitigating cognitive decline and improving the overall quality of life in patients with MCI.

Exercise effects on neuropsychiatric symptoms and quality of life in mild cognitive impairment: a systematic review and meta-analysis

Background

Exercise is considered as a cost-efficient option for individuals with mild cognitive impairment (MCI). Although the potential benefits of exercise for improving cognitive function are recognized, its impact on neuropsychiatric symptoms (NPS) and the quality of life (QoL) in individuals with MCI remains unclear.

Objective

This study aims to investigate the effects of exercise interventions on NPS, including depression, anxiety, sleep disorders, and the quality of life in individuals with MCI.

Results

There were 17 randomized controlled trials (RCTs) involving 1,575 participants were included. The findings indicate a small but significant positive effect of exercise on depression (standardized mean difference [SMD] = -0.47, 95% confidence interval [CI]: -0.73 to -0.21), but the quality of the evidence is low. Mind-body exercises were relatively more effective in alleviating depression. No significant improvements were observed in sleep disorders (SMD = -1.27, 95% CI: -2.80 to 0.26). Exercise improved anxiety in one study but had no effect in the other. It also improved quality of life in seven studies, with two showing no effect.

Conclusion

The findings suggest that exercise, particularly mind-body exercises, can improve depression in individuals with MCI. However, the effect of exercise on anxiety, sleep disorders, and quality of life is still uncertain, necessitating additional research. These findings underscore the significance of integrating customized exercise programs in managing MCI to boost quality of life and mitigate NPS.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/. ID: CRD42023445369.

EBF1 is a potential biomarker for predicting progression from mild cognitive impairment to Alzheimer's disease: an in silico study

Introduction

The prediction of progression from mild cognitive impairment (MCI) to Alzheimer's disease (AD) is an important clinical challenge. This study aimed to identify the independent risk factors and develop a nomogram model that can predict progression from MCI to AD.

Methods

Data of 141 patients with MCI were obtained from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. We set a follow-up time of 72 months and defined patients as stable MCI (sMCI) or progressive MCI (pMCI) according to whether or not the progression of MCI to AD occurred. We identified and screened independent risk factors by utilizing weighted gene co-expression network analysis (WGCNA), where we obtained 14,893 genes after data preprocessing and selected the soft threshold β = 7 at an R 2 of 0.85 to achieve a scale-free network. A total of 14 modules were discovered, with the midnightblue module having a strong association with the prognosis of MCI. Using machine learning strategies, which included the least absolute selection and shrinkage operator and support vector machine-recursive feature elimination; and the Cox proportional-hazards model, which included univariate and multivariable analyses, we identified and screened independent risk factors. Subsequently, we developed a nomogram model for predicting the progression from MCI to AD. The performance of our nomogram was evaluated by the C-index, calibration curve, and decision curve analysis (DCA). Bioinformatics analysis and immune infiltration analysis were conducted to clarify the function of early B cell factor 1 (EBF1).

Results

First, the results showed that 40 differentially expressed genes (DEGs) related to the prognosis of MCI were generated by weighted gene co-expression network analysis. Second, five hub variables were obtained through the abovementioned machine learning strategies. Third, a low Montreal Cognitive Assessment (MoCA) score [hazard ratio (HR): 4.258, 95% confidence interval (CI): 1.994-9.091] and low EBF1 expression (hazard ratio: 3.454, 95% confidence interval: 1.813-6.579) were identified as the independent risk factors through the Cox proportional-hazards regression analysis. Finally, we developed a nomogram model including the MoCA score, EBF1, and potential confounders (age and gender). By evaluating our nomogram model and validating it in both internal and external validation sets, we demonstrated that our nomogram model exhibits excellent predictive performance. Through the Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes Genomes (KEGG) functional enrichment analysis, and immune infiltration analysis, we found that the role of EBF1 in MCI was closely related to B cells.

Conclusion

EBF1, as a B cell-specific transcription factor, may be a key target for predicting progression from MCI to AD. Our nomogram model was able to provide personalized risk factors for the progression from MCI to AD after evaluation and validation.

A randomized, double-blind, placebo-controlled study of Cistanche tubulosa and Ginkgo biloba extracts for the improvement of cognitive function in middle-aged and elderly people

Mild cognitive impairment poses an increasing challenge to middle-aged and elderly populations. Traditional Chinese medicinal herbs like Cistanche tubulosa and Ginkgo biloba (CG) have been proposed as potential agents to improve cognitive and memory functions. A randomized controlled trial involving 100 Chinese middle-aged and elderly participants was conducted to investigate the potential synergistic effects of CG on cognitive function in individuals at risk of neurodegenerative diseases. Over 90 days, both CG group and placebo group received two tablets daily, with each pair of CG tablets containing 72 mg echinacoside and 27 mg flavonol glycosides. Cognitive functions were assessed using multiple scales and blood biomarkers were determined at baseline, Day 45, and Day 90. The CG group exhibited significant improvements in the scores of Mini-Mental State Examination (26.5 at baseline vs. 27.1 at Day 90, p < 0.001), Montreal Cognitive Assessment (23.4 at baseline vs. 25.3 at Day 90, p < 0.001), and World Health Organization Quality of Life (81.6 at baseline vs. 84.2 at Day 90, p < 0.001), all surpassing scores in placebo group. Notably, both the Cognitrax matrix test and the Wechsler Memory Scale-Revised demonstrated enhanced memory functions, including long-term and delayed memory, after CG intervention. Moreover, cognitive-related blood biomarkers, including total tau, pT181, pS199, pT231, pS396, and thyroid-stimulating hormone, significantly decreased, whereas triiodothyronine and free triiodothyronine significantly increased. No treatment-related adverse events were reported, and routine blood and urine tests remained stable. These findings indicated that CG supplementation could potentially serve as an effective supplementary solution for enhancing cognitive and memory functions.

Assessing and recovering Alzheimer's disease: a comparative analysis of standard neuropsychological approaches and virtual reality interventions with the use of digital storytelling

Background

Alzheimer's disease (AD), the most common form of dementia, is a progressive neurodegenerative disorder that predominantly affects the elderly population. Traditional assessment methods, including neuropsychological tests like the MMSE, have been the cornerstone of AD diagnosis for decades. These methods are grounded in a wealth of research and clinical experience, providing a robust framework for understanding the cognitive deficits of AD. The evolution of AD assessment and rehabilitation has recently been tackled with the introduction of Virtual Reality (VR) technologies.

Objectives

To evaluate the use of storytelling and reminiscence therapy in virtual reality programs as a complementary and enhancing modality alongside standard assessment and rehabilitation for Alzheimer's patients. To explore how regular interaction with VR narratives can slow cognitive decline or improve relevant features of cognitive functioning over the time. To propose a new assessment and rehabilitative tool based on the use of VR and digital storytelling.

Method

A comparative analysis of Standard Neuropsychological Approaches and Virtual Reality Interventions in patients with Alzheimer disorder was carried out. A literature overview on the empirical studies between 2019 and 2024 was conducted.

Results

We propose a new VR-based setup mediated by the use of storytelling for the assessment and recovery of AD.

Conclusion

The employment of storytelling within VR programs for the assessment and rehabilitation of Alzheimer's disease can positively impact both the cognitive and emotional realms of patients, with beneficial outcomes on caregivers' and families' burden. The successful implementation of this approach requires careful consideration of accessibility, data interpretation, and standard validation protocols.

Association of physical activity and vitamin D deficiency with cognitive impairment in older adults: a population based cross-sectional analysis

Objectives

The global aging situation is becoming increasingly critical and cognitive impairment in the elderly has become a public health burden of concern. Physical activity (PA) and vitamin D may play a key role in improving cognitive impairment. However, little studies have examined the interaction between these two. The purpose of this study was to assess the association of PA and vitamin D with cognitive impairment in older adults, as well as the interactions of PA and vitamin D.

Materials and methods

This study was conducted by multi-stage random sampling of elderly people ≥60 years old, and a total sample of 2,492 (1,207 male and 1,285 female, mean age of 69.41 ± 6.75 years) with complete data was included in the analysis. PA was assessed by the Global Physical Activity Questionnaire, and < 600 MET-min/week was used as the division criteria. Serum vitamin D was measured by high-performance liquid chromatography tandem mass spectrometry, and 25-hydroxyvitamin D2/D3 concentration < 20 ng/mL was used as a vitamin D deficiency criterion. Cognitive function was assessed by three subtests: the Consortium to Establish a Registry for Alzheimer's disease word learning test (CERAD-WL) for immediate and delayed learning, the Animal Fluency Test (AFT) for verbal fluency; and the Digit Symbol Substitution Test (DSST) for information processing speed and switching attention. All three subtests were scored at less than the lowest quartile of the score as a criterion for cognitive impairment. Statistical analysis was performed using SPSS for chi-square test, rank sum test, interaction analysis, subgroup analysis, and regression analysis.

Results

Lower level of PA is associated with higher odds of cognitive impairment (CERAD W-L: OR = 1.596, 95% CI: 1.338-1.905, p < 0.001; AFT: OR = 1.833, 95% CI: 1.534-2.190, p < 0.001; DSST: OR = 1.936, 95% CI: 1.609-2.329, p < 0.001). Vitamin D deficiency has significant effects in AFT (OR = 1.322, 95% CI: 1.103-1.584, p = 0.003) and DSST (OR = 1.619, 95% CI: 1.345-1.948, p < 0.001). After adjusted for covariates, PA and vitamin D have multiplicative interaction on AFT (OR = 0.662, 95% CI: 0.448-0.977, p = 0.038) and DSST (OR = 0.775, 95% CI: 0.363-0.868, p = 0.009). The interaction between PA and vitamin D was not significant in the CERAD W-L (OR = 0.757, 95% CI: 0.508-1.128, p = 0.172).

Conclusion

The results showed that lower level of PA and vitamin D deficiency were associated with higher odds of cognitive impairment in the elderly population and that there was a multiplicative interaction between PA and vitamin D on cognitive function, with a significant effect of vitamin D on cognitive impairment in high PA conditions.

Platelet Dynamics in Neurodegenerative Disorders: Investigating the Role of Platelets in Neurological Pathology

Background: Neurological disorders, particularly those associated with aging, pose significant challenges in early diagnosis and treatment. The identification of specific biomarkers, such as platelets (PLTs), has emerged as a promising strategy for early detection and intervention in neurological health. This systematic review aims to explore the intricate relationship between PLT dynamics and neurological health, focusing on their potential role in cognitive functions and the pathogenesis of cognitive disorders. Methods: Adhering to PRISMA guidelines, a comprehensive search strategy was employed in the PubMed and Scholar databases to identify studies on the role of PLTs in neurological disorders published from 2013 to 2023. The search criteria included studies focusing on PLTs as biomarkers in neurological disorders, their dynamics, and their potential in monitoring disease progression and therapy effectiveness. Results: The systematic review included 104 studies, revealing PLTs as crucial biomarkers in neurocognitive disorders, acting as inflammatory mediators. The findings suggest that PLTs share common features with altered neurons, which could be utilised for monitoring disease progression and evaluating the effectiveness of treatments. PLTs are identified as significant biomarkers for detecting neurological disorders in their early stages and understanding the pathological events leading to neuronal death. Conclusions: The systematic review underscores the critical role of PLTs in neurological disorders, highlighting their potential as biomarkers for the early detection and monitoring of disease progression. However, it also emphasises the need for further research to solidify the use of PLTs in neurological disorders, aiming to enhance early diagnosis and intervention strategies.

Investigation of the Approaches to Optimal Exercise Interventions Based on Dementia Type: A Theoretical Review

The aim of this study is to enhance comprehension of the different types and features of dementia, including their symptoms, diagnosis and medical treatment, and to propose various evidence-based exercise interventions and their clinical applications tailored to each specific type of dementia. The theoretical review includes the analysis of publications in the scientific databases PubMed/Medline, Ebsco, Scielo, and Google. A total of 177 articles were found, of which 84 were studied in depth. With the prevalence of all forms of dementia projected to increase from 57.4 million in 2019 to 152.8 million in 2050, personalized treatment strategies are needed. This review discusses various forms of dementia, including their pathologies, diagnostic criteria, and prevalence rates. The importance of accurate diagnosis and tailored care is emphasized, as well as the effectiveness of physical exercise in improving cognitive function in dementia patients. For Alzheimer's, a combination of drug therapies and exercises is recommended to enhance cerebral blood flow and neurotransmitter activity. To improve cognitive and motor functions in Lewy body dementia, a combination of pharmacological and physical therapies is recommended. For managing frontotemporal dementia, a mix of medication and exercises aimed at emotion regulation, including aerobic exercises, and a unified protocol, is suggested. For mild cognitive impairment, aerobic and functional exercises are important in delaying cognitive decline and enhancing cognitive performance. In conclusion, individualized care and treatment plans tailored to the specific characteristics of each disease type can improve the quality of life for individuals with this condition and effectively manage this growing global health issue.

Intelligent digital tools for screening of brain connectivity and dementia risk estimation in people affected by mild cognitive impairment: the AI-Mind clinical study protocol

More than 10 million Europeans show signs of mild cognitive impairment (MCI), a transitional stage between normal brain aging and dementia stage memory disorder. The path MCI takes can be divergent; while some maintain stability or even revert to cognitive norms, alarmingly, up to half of the cases progress to dementia within 5 years. Current diagnostic practice lacks the necessary screening tools to identify those at risk of progression. The European patient experience often involves a long journey from the initial signs of MCI to the eventual diagnosis of dementia. The trajectory is far from ideal. Here, we introduce the AI-Mind project, a pioneering initiative with an innovative approach to early risk assessment through the implementation of advanced artificial intelligence (AI) on multimodal data. The cutting-edge AI-based tools developed in the project aim not only to accelerate the diagnostic process but also to deliver highly accurate predictions regarding an individual's risk of developing dementia when prevention and intervention may still be possible. AI-Mind is a European Research and Innovation Action (RIA H2020-SC1-BHC-06-2020, No. 964220) financed between 2021 and 2026. First, the AI-Mind Connector identifies dysfunctional brain networks based on high-density magneto- and electroencephalography (M/EEG) recordings. Second, the AI-Mind Predictor predicts dementia risk using data from the Connector, enriched with computerized cognitive tests, genetic and protein biomarkers, as well as sociodemographic and clinical variables. AI-Mind is integrated within a network of major European initiatives, including The Virtual Brain, The Virtual Epileptic Patient, and EBRAINS AISBL service for sensitive data, HealthDataCloud, where big patient data are generated for advancing digital and virtual twin technology development. AI-Mind's innovation lies not only in its early prediction of dementia risk, but it also enables a virtual laboratory scenario for hypothesis-driven personalized intervention research. This article introduces the background of the AI-Mind project and its clinical study protocol, setting the stage for future scientific contributions.

Association of psychological resilience and cognitive function in older adults: Based on the Ma' anshan Healthy Aging Cohort Study

OBJECTIVES

The purpose of this study was to explore whether psychological resilience can influence changes in cognitive function in older adults and provide clues and rationale for improving cognitive function and preventing the onset of dementia in the geriatric population.

METHODS

A total of 2495 older adults aged 60 years or older from the Ma' anshan Healthy Aging Cohort were included in the study. Participants' cognitive functioning and psychological resilience were measured using the MMSE (mini-mental state examination) scale and the SRQS (stress resilience quotient scale) scale during the 5 years of follow-up, and the association was explored. Those with MMSE scores ≤ 17 in the illiterate group, ≤ 20 in the elementary school group, and ≤ 24 in the secondary school and above group were considered cognitive impairment.

RESULTS

The prevalence of cognitive impairment increased from 6.89% to 14.30% during the five years of follow-up. At 5-year follow-up, the group with the highest psychological resilience had 41 (6.83%) individuals whose cognitive functioning changed from normal to cognitive impairment, while the group with the worst psychological resilience had 114 (18.33%) individuals. The study also found a significant effect of different levels of psychological resilience on changes in cognitive functioning after adjusting for potential confounders. Compared with Q1 (the reference group), the Odds ratio of cognitive decline in Q2, Q3 and Q4 groups were 0.51(0.42,0.64), 0.37(0.29,0.47) and 0.19(0.13,0.27), respectively.

CONCLUSIONS

Improving the level of psychological resilience in older adults may be one way to prevent the incidence of cognitive impairment.

Effectiveness of Tai Chi on cognitive function among older adults with mild cognitive impairment: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the effectiveness of Tai Chi on cognitive function in older adults with mild cognitive impairment.

METHODS

A systematic search of eight English and five Chinese electronic databases was conducted to identify randomized controlled trials of Tai Chi as the intervention. The main outcomes included executive function, episodic memory, visuospatial function, working memory, concentration, memory complaints, and global cognition. The Cochrane RoB tool was used to assess bias in the study. Meta-analysis was conducted using Review Manager 5.4. Narrative syntheses were performed if meta-analysis was inappropriate.

RESULTS

A total of eleven trials (905 participants) were included. Meta-analysis showed that Tai Chi significantly and moderately affected executive function (SMD = -1.01, 95% CI: -1.54 to -0.47, p < 0.001), episodic memory (SMD = 0.59, 95% CI: 0.24 to 0.94, p = 0.001), visuospatial function (SMD = 0.38, 95% CI: 0.15 to 0.60, p < 0.001), and global cognition (SMD = 0.57, 95% CI: 0.14 to 1.00, p = 0.01).One study showed that Tai Chi could improve verbal fluency.

CONCLUSIONS

This review reveals that Tai Chi can improve executive function, episodic memory, visuospatial function, and global cognition in older adults with mild cognitive impairment, but not working memory, concentration, or memory complaints. These findings are consist with existing reviews about the effectiveness of Tai Chi. Long-duration (> 1500 min) Tai Chi is more effective for improving global cognition. However, the findings should be interpreted with caution due to the potential risk of bias and limited sample sizes of the included studies. Future trials should examine the effectiveness of standardized Tai Chi intervention on cognitive outcomes in older adults with mild cognitive impairment.

Effect of acupuncture on mild cognitive impairment in the elderly: A randomized controlled trial

Background and objective

Mild cognitive impairment (MCI) is a cognitive dysfunction syndrome defined mostly by memory or other cognitive impairments, and may serve as a precursor to Alzheimer's disease (AD). In recent years, acupuncture has gained recognition as a potential intervention for MCI, attracting significant attention as a promising and well-established therapy. In this study, we critically evaluate the clinical efficacy and safety of an innovative acupuncture approach, termed "Kidney Nourishment and Spirit Regulation", as a therapeutic modality for MCI in geriatric populations.

Methods

A prospective, randomized, single-blind, placebo-controlled, single-center clinical trial design where patients will be allocated in acupuncture, placebo (sham acupuncture sessions), or blank for eight weeks. The blank group will receive health education over the same eight-week period and will be offered compensatory acupuncture therapy after this period. The selected acupoints for this investigation include GV20, EX-HN1, GV24, GV29, CV6, CV4, PC6, KI3, LI4, LR3, HT7 and SP6. The primary outcome measure will be the Montreal Cognitive Assessment (MoCA), while secondary outcomes include the Mini Mental State Examination (MMSE), Activity of Daily Living (ADL), and Electroencephalogram (EEG).

Discussion

This study seeks to provide an optimum regimen for acupuncture therapy in elderly MCI patients and to provide considerable theoretical evidence for its popularization and future broad adoption. We thus postulate that the current trial data might enlighten and potentially guide future research in terms of study design refinement.

Diagnostic performance of MRI radiomics for classification of Alzheimer's disease, mild cognitive impairment, and normal subjects: a systematic review and meta-analysis

BACKGROUND

Alzheimer's disease (AD) is a debilitating neurodegenerative disease. Early diagnosis of AD and its precursor, mild cognitive impairment (MCI), is crucial for timely intervention and management. Radiomics involves extracting quantitative features from medical images and analyzing them using advanced computational algorithms. These characteristics have the potential to serve as biomarkers for disease classification, treatment response prediction, and patient stratification. Of note, Magnetic resonance imaging (MRI) radiomics showed a promising result for diagnosing and classifying AD, and MCI from normal subjects. Thus, we aimed to systematically evaluate the diagnostic performance of the MRI radiomics for this task.

METHODS AND MATERIALS

A comprehensive search of the current literature was conducted using relevant keywords in PubMed/MEDLINE, Embase, Scopus, and Web of Science databases from inception to August 5, 2023. Original studies discussing the diagnostic performance of MRI radiomics for the classification of AD, MCI, and normal subjects were included. Method quality was evaluated with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) and the Radiomics Quality Score (RQS) tools.

RESULTS

We identified 13 studies that met the inclusion criteria, involving a total of 5448 participants. The overall quality of the included studies was moderate to high. The pooled sensitivity and specificity of MRI radiomics for differentiating AD from normal subjects were 0.92 (95% CI [0.85; 0.96]) and 0.91 (95% CI [0.85; 0.95]), respectively. The pooled sensitivity and specificity of MRI radiomics for differentiating MCI from normal subjects were 0.74 (95% CI [0.60; 0.85]) and 0.79 (95% CI [0.70; 0.86]), respectively. Also, the pooled sensitivity and specificity of MRI radiomics for differentiating AD from MCI were 0.73 (95% CI [0.64; 0.80]) and 0.79 (95% CI [0.64; 0.90]), respectively.

CONCLUSION

MRI radiomics has promising diagnostic performance in differentiating AD, MCI, and normal subjects. It can potentially serve as a non-invasive and reliable tool for early diagnosis and classification of AD and MCI.

The application of saccades to assess cognitive impairment among older adults: a systematic review and meta-analysis

BACKGROUND

Saccade is a novel and feasible method for cognition assessment and has potential to screen older people with cognitive impairment.

OBJECTIVES

To systematically summarize the evidence and determine whether different saccade parameters can effectively identify patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD).

METHODS

English and Chinese databases were searched until 19 April 2022. Studies analyzing saccade parameters in older adults with normal cognition, MCI, or AD were included. Two researchers independently performed the screening, data extraction, and quality appraisal. Meta-analyses were conducted and standard mean differences and 95% confidence intervals were estimated with a random effects model.

RESULTS

Thirty-five studies were included, and 26 studies were pooled for the meta-analysis. The results demonstrated that patients with cognitive impairment exhibited longer latency and lower accuracy rates in the prosaccade and antisaccade tasks, along with lower corrected error rates in the antisaccade tasks. However, the pooled results for antisaccades were more stable, providing the ability to distinguish patients with cognitive impairment among older adults. The results of the subgroup analyses revealed that only the accuracy rates of the antisaccades differed significantly between people with MCI and AD. Regarding the differences between older adults with normal cognition and those with MCI, the effect sizes of latency and the accuracy rates of saccades as well as the corrected error rates of antisaccades were significant.

CONCLUSIONS

Saccades, especially antisaccades, are a potential screening and assessment tool for distinguishing older adults with MCI or AD from those with normal cognition.

The Efficacy of Cognitive Training on Neuropsychological Outcomes in Mild Cognitive Impairment: A Meta-Analysis

Mild cognitive impairment (MCI) or mild neurocognitive disorder is an intermediate stage of cognitive impairment between normal cognitive aging and dementia. Given the absence of effective pharmacological treatments for MCI, increasing numbers of studies are attempting to understand how cognitive training (CT) could benefit MCI. This meta-analysis aims to update and assess the efficacy of CT on specific neuropsychological test performance (global cognitive functioning, short-term verbal memory, long-term verbal memory, generativity, working memory, and visuospatial abilities) in individuals diagnosed with MCI, as compared to MCI control groups. After searching electronic databases for randomized controlled trials, 31 studies were found including 2496 participants. Results showed that CT significantly improved global cognitive functioning, short-term and long-term verbal memory, generativity, working memory, and visuospatial abilities. However, no significant effects were observed for shifting, abstraction ability/concept formation, processing speed, and language. The mode of CT had a moderating effect on abstraction ability/concept formation. The findings provide specific insights into the cognitive functions influenced by CT and guide the development of tailored interventions for MCI. While CT holds promise, further research is needed to address certain cognitive deficits and assess long-term effects on dementia progression.

Repetitive Transcranial Magnetic Stimulation (rTMS) in Mild Cognitive Impairment: Effects on Cognitive Functions-A Systematic Review

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique also used as a non-pharmacological intervention against cognitive impairment. The purpose of the present review was to summarize what is currently known about the effectiveness of rTMS intervention on different cognitive domains in patients with mild cognitive impairment (MCI) and to address potential neuromodulation approaches in combination with electroencephalography (EEG) and neuroimaging, especially functional magnetic resonance imaging (fMRI). In this systematic review, we consulted three main databases (PubMed, Science Direct, and Scopus), and Google Scholar was selected for the gray literature search. The PRISMA flowchart drove the studies' inclusion. The selection process ensured that only high-quality studies were included; after removing duplicate papers, explicit ratings were given based on the quality classification as high (A), moderate (B), or low (C), considering factors such as risks of bias, inaccuracies, inconsistencies, lack of direction, and publication bias. Seven full-text articles fulfilled the stated inclusion, reporting five double-blind, randomized, sham-controlled studies, a case study, and a randomized crossover trial. The results of the reviewed studies suggested that rTMS in MCI patients is safe and effective for enhancing cognitive functions, thus making it a potential therapeutic approach for MCI patients. Changes in functional connectivity within the default mode network (DMN) after targeted rTMS could represent a valuable indicator of treatment response. Finally, high-frequency rTMS over the dorsolateral prefrontal cortex (DLPFC) has been shown to significantly enhance cognitive functions, such as executive performance, together with the increase of functional connectivity within frontoparietal networks. The main limitations were the number of included studies and the exclusion of studies using intermittent theta-burst stimulation, used in studies on Alzheimer's disease. Therefore, neuroimaging techniques in combination with rTMS have been shown to be useful for future network-based, fMRI-guided therapeutic approaches.

Combining ADC values in DWI with rCBF values in arterial spin labeling (ASL) for the diagnosis of mild cognitive impairment (MCI)

We aimed to investigate the role of combined apparent diffusion coefficient (ADC) values and relative cerebral blood flow (rCBF) values in the diagnosis of mild cognitive impairment (MCI) patients. The present prospective research enrolled 156 MCI patients and 58 healthy elderly people who came to our hospital from January 2021 to February 2023. T1W, T2W, diffusion-weighted imaging, and arterial spin labeling sequences were performed on all subjects, and ADC values and rCBF values were measured at the workstation. Clinical and demographic data of all patients were collected while mini-mental state examination (MMSE) and Montreal cognitive assessment (MoCA) scores were used to assess patients' cognitive abilities. The MCI group had significantly lower rCBF values in the left frontal lobe, left occipital lobe, right frontal lobe, and right occipital lobe than the HC group. The ADC values in the left frontal lobe as well as the right frontal lobe were remarkably elevated in the MCI group than in the HC group. MoCA and MMSE scores were positively correlated with rCBF values in the left frontal, right frontal, left occipital, and right occipital lobes and negatively correlated with ADC values in the left and right frontal lobes. Combined ADC values and rCBF values from the left frontal lobe for the diagnosis of MCI had a higher sensitivity and specificity with the AUC was 0.877, sensitivity 81.0%, specificity 82.7%. Additionally, pressure fasting plasma glucose, ADC of the left frontal lobe, right frontal lobe, rCBF of left frontal lobe and rCBF of left frontal lobe were the risk factors of patients with MCI. In summary, our results indicated that the ADC values and rCBF values were changed in MCI group compared to HC group and correlated with MMSE and MoCA scores.

Investigating predictors of progression from mild cognitive impairment to Alzheimer's disease based on different time intervals

BACKGROUND

Mild cognitive impairment (MCI) is the early stage of AD, and about 10-12% of MCI patients will progress to AD every year. At present, there are no effective markers for the early diagnosis of whether MCI patients will progress to AD. This study aimed to develop machine learning-based models for predicting the progression from MCI to AD within 3 years, to assist in screening and prevention of high-risk populations.

METHODS

Data were collected from the Alzheimer's Disease Neuroimaging Initiative, a representative sample of cognitive impairment population. Machine learning models were applied to predict the progression from MCI to AD, using demographic, neuropsychological test and MRI-related biomarkers. Data were divided into training (56%), validation (14%) and test sets (30%). AUC (area under ROC curve) was used as the main evaluation metric. Key predictors were ranked utilising their importance.

RESULTS

The AdaBoost model based on logistic regression achieved the best performance (AUC: 0.98) in 0-6 month prediction. Scores from the Functional Activities Questionnaire, Modified Preclinical Alzheimer Cognitive Composite with Trails test and ADAS11 (Unweighted sum of 11 items from The Alzheimer's Disease Assessment Scale-Cognitive Subscale) were key predictors.

CONCLUSION

Through machine learning, neuropsychological tests and MRI-related markers could accurately predict the progression from MCI to AD, especially in a short period time. This is of great significance for clinical staff to screen and diagnose AD, and to intervene and treat high-risk MCI patients early.

Central and Peripheral Inflammation in Mild Cognitive Impairment in the Context of Alzheimer's Disease

Mild cognitive impairment (MCI) is characterized by an abnormal decline in mental and cognitive function compared with normal cognitive aging. It is an underlying condition of Alzheimer's disease (AD), an irreversible neurodegenerative disease. In recent years, neuroinflammation has been investigated as a new leading target that contributes to MCI progression into AD. Understanding the mechanism underlying inflammatory processes involved in the early onset of the disease could help find a safe and effective way to diagnose and treat patients. In this article, we assessed over twenty different blood and cerebrospinal fluid (CSF) inflammatory biomarker concentrations with immunoassay methods in patients with MCI (mild cognitive impairment), non-impaired control (NIC), and serum healthy control (HC). We performed group comparisons and analyzed in-group correlations between the biomarkers. We included 107 participants (mean age: 64.7 ± 7.8, women: 58.9%). CSF osteopontin and YKL-40 were significantly increased in the MCI group, whereas serum C-reactive protein and interleukin-6 were significantly higher (p < 0.001) in the NIC group compared with the MCI and HC groups. Stronger correlations between interleukin-1β and inflammasome markers were observed in the serum of the MCI group. We confirmed specific inflammatory activation in the central nervous system and interleukin-1β pathway upregulation in the serum of the MCI cohort.

Probiotic intervention benefits multiple neural behaviors in older adults with mild cognitive impairment

Probiotic supplements were shown to improve cognitive function in Alzheimer's disease (AD) patients. However, it is still unclear whether this applies to older individuals with mild cognitive impairment (MCI). We aimed to explore the effects of probiotic supplementation on multiple neural behaviors in older adults with MCI. Forty-two MCI patients (age > 60 years) were randomly divided into two groups and consumed either probiotics (n=21) or placebo (n=21) for 12 weeks. Various scale scores, gut microbiota measures and serological indicators were recorded pre- and posttreatment. After 12 weeks of intervention, cognitive function and sleep quality were improved in the probiotic group compared with those in the control group, and the underlying mechanisms were associated with changes in the intestinal microbiota. In conclusion, our study demonstrated that probiotic treatment enhanced cognitive function and sleep quality in older MCI patients, thus providing important insights into the clinical prevention and treatment of MCI.

The Potential Role of Gustatory Function as an Early Diagnostic Marker for the Risk of Alzheimer’s Disease in Subjective Cognitive Decline

Background: Patients with subjective cognitive decline (SCD) report memory deterioration and are at an increased risk of converting to Alzheimer’s disease (AD) although psychophysical testing does not reveal any cognitive deficit. Objective: Here, gustatory function is investigated as a potential predictor for an increased risk of progressive cognitive decline indicating higher AD risk in SCD. Methods: Measures of smell and taste perception as well as neuropsychological data were assessed in patients with subjective cognitive decline (SCD): Subgroups with an increased likelihood of the progression to preclinical AD (SCD+) and those with a lower likelihood (SCD–) were compared to healthy controls (HC), patients with mild cognitive impairment and AD patients. The Sniffin’ Sticks test contained 12 items with different qualities and taste was measured with 32 taste stripes (sweet, salty, bitter, sour) of different concentration. Results: Only taste was able to distinguish between HC/SCD– and SCD+ patients. Conclusion: This study provides a first hint of taste as a more sensitive marker than smell for detecting preclinical AD in SCD. Longitudinal observation of cognition and pathology are necessary to further evaluate taste perception as a predictor of pathological objective decline in cognition.

The Association of Calcium Signaling Pathway Gene Variants, Bone Mineral Density and Mild Cognitive Impairment in Elderly People

The association of calcium signaling pathway gene variants, bone mineral density (BMD) and mild cognitive impairment (MCI) is poorly understood so far. A total of 878 participants from Qingdao city were recruited in this study. According to the candidate gene selection method, 58 single nucleotide polymorphisms (SNPs) in eight calcium signaling genes were selected. The association between gene polymorphisms and MCI was revealed by using multiple genetic models. Polygenic risk scores (PRS) were used to summarize the effects of the whole gene. Logistic regression was used to analyze the association between each PRS and MCI. The multiplicative interaction term in the regression models was used to estimate the interaction effects between the PRS and BMD. We observed significant associations of rs6877893 (NR3C1), rs6448456 (CCKAR), and rs723672 (CACNA1C) polymorphisms with MCI. The PRSs of NR3C1 (OR = 4.012, 95% CI = 1.722-9.347, p < 0.001), PRKCA (OR = 1.414, 95% CI = 1.083-1.845, p = 0.011) and TRPM1 (OR = 3.253, 95% CI = 1.116-9.484, p = 0.031) were associated with an increased risk of developing MCI, and the PRS of total genes (OR = 0.330, 95% CI = 0.224-0.485, p < 0.001) was associated with a decreased risk of developing MCI. In interaction effect analysis, the interaction effect of PRKCA and BMD was significant. Genetic variations of the calcium signaling pathway were associated with MCI in older people. There was an interaction effect between PRKCA gene variants and BMD on MCI.

Retinal Alterations as Potential Biomarkers of Structural Brain Changes in Alzheimer’s Disease Spectrum Patients

Retinal imaging being a potential biomarker for Alzheimer’s disease is gradually attracting the attention of researchers. However, the association between retinal parameters and AD neuroimaging biomarkers, particularly structural changes, is still unclear. In this cross-sectional study, we recruited 25 cognitively impaired (CI) and 21 cognitively normal (CN) individuals. All subjects underwent retinal layer thickness and microvascular measurements with optical coherence tomography angiography (OCTA). Gray matter and white matter (WM) data such as T1-weighted magnetic resonance imaging and diffusion tensor imaging, respectively, were also collected. In addition, hippocampal subfield volumes and WM tract microstructural alterations were investigated as classical AD neuroimaging biomarkers. The microvascular and retinal features and their correlation with brain structural imaging markers were further analyzed. We observed a reduction in vessel density (VD) at the inferior outer (IO) sector (p = 0.049), atrophy in hippocampal subfield volumes, such as the subiculum (p = 0.012), presubiculum (p = 0.015), molecular_layer_HP (p = 0.033), GC-ML-DG (p = 0.043) and whole hippocampus (p = 0.033) in CI patients. Altered microstructural integrity of WM tracts in CI patients was also discovered in the cingulum hippocampal part (CgH). Importantly, we detected significant associations between retinal VD and gray matter volumes of the hippocampal subfield in CI patients. These findings suggested that the retinal microvascular measures acquired by OCTA may be markers for the early prediction of AD-related structural brain changes.

The Protective Role of Cognitive Reserve in Mild Cognitive Impairment: A Systematic Review

Cognitive reserve (CR) represents the ability to optimize performance and functioning to cope with brain damage or disease. CR reflects the capability to adaptively and flexibly use cognitive processes and brain networks to compensate for the deterioration typical of aging. Several studies have investigated the potential role of CR in aging, especially from the perspective of preventing and protecting against dementia and Mild Cognitive Impairment (MCI). This systematic literature review aimed to investigate the role of CR as a protective factor against MCI and associated cognitive decline. The review process was conducted according to the PRISMA statement. For this purpose, ten studies were analyzed. The results of this review show that high CR is significantly associated with a reduced risk of MCI. In addition, a significant positive relationship between CR and cognitive functioning is observed when comparing subjects with MCI and healthy subjects and within people with MCI. Thus, the results confirm the positive role of cognitive reserve in mitigating cognitive impairment. The evidence from this systematic review is consistent with the theoretical models of CR. Indeed, previous research hypothesized that specific individual experiences (such as leisure activities) allow a person to acquire successful neural resources over the years to cope with cognitive decline.

Cognitive Computerized Training for Older Adults and Patients with Neurological Disorders: Do the Amount and Training Modality Count? An Umbrella Meta-Regression Analysis

Numerous applications have been created to train cognition and challenge the brain, a process known as computerized cognitive training (CCT). Despite potential positive results, important questions remain unresolved: the appropriate training duration, the efficacy of CCT depending on its type (commercial or developed in-house for the rehabilitation of specific patients) and delivery mode (at-home or on-site), and the patients most likely to benefit such intervention. This study aims to perform an umbrella meta-analysis and meta-regression to determine if the type of CCT, the delivery mode, the amount of training, and participants' age at inclusion influence the improvement of the cognitive function. To do so, we performed a umbrella meta-analysis. One hundred studies were included in this analysis representing 6407 participants. Statistical improvements were found for the different conditions after the training. We do not find statistical difference between the type of intervention or the delivery mode. No dose-response relationship between the total amount of training and the improvement of cognitive functions was found. CCT is effective in improving cognitive function in patients suffering from neurological conditions and in healthy aging. There is therefore an urgent need for health care systems to recognize its therapeutic potential and to evaluate at a larger scale their integration into the clinical pipeline as preventive and rehabilitation tool.

Alzheimer's Disease: A Systems View Provides a Unifying Explanation of Its Development

Alzheimer's disease (AD) is a debilitating neurodegenerative disorder affecting 50 million people globally. It is characterized by the presence of extracellular senile plaques and intracellular neurofibrillary tangles, consisting of amyloid-β and hyperphosphorylated tau proteins, respectively. Despite global research efforts, there is currently no cure available, due in part to an incomplete understanding of the disease pathogenesis. Numerous possible mechanisms, or hypotheses, explaining the origins of sporadic or late-onset AD have been proposed, including the amyloid-β, inflammatory, vascular, and infectious hypotheses. However, despite ample evidence, the failure of multiple trial drugs at the clinical stage illuminates the possible pitfalls of these hypotheses. Systems biology is a strategy which aims to elucidate the interactions between parts of a whole. Using this approach, the current paper shows how the four previously mentioned hypotheses of AD pathogenesis can be intricately connected. This approach allows for seemingly contradictory evidence to be unified in a system-focused explanation of sporadic AD development. Within this view, it is seen that infectious agents, such as P. gingivalis, may play a central role. The data presented here shows that when present, P. gingivalis or its virulence factors, such as gingipains, may induce or exacerbate pathologies underlying sporadic AD. This evidence supports the view that infectious agents, and specifically P. gingivalis, may be suitable treatment targets in AD.

Decreased Brain Structural Network Connectivity in Patients with Mild Cognitive Impairment: A Novel Fractal Dimension Analysis

Mild cognitive impairment (MCI) is widely regarded to be the intermediate stage to Alzheimer's disease. Cerebral morphological alteration in cortical subregions can provide an accurate predictor for early recognition of MCI. Thirty patients with MCI and thirty healthy control subjects participated in this study. The Desikan-Killiany cortical atlas was applied to segment participants' cerebral cortex into 68 subregions. A complexity measure termed fractal dimension (FD) was applied to assess morphological changes in cortical subregions of participants. The MCI group revealed significantly decreased FD values in the bilateral temporal lobes, right parietal lobe including the medial temporal, fusiform, para hippocampal, and also the orbitofrontal lobes. We further proposed a novel FD-based brain structural network to compare network parameters, including intra- and inter-lobular connectivity between groups. The control group had five modules, and the MCI group had six modules in their brain networks. The MCI group demonstrated shrinkage of modular sizes with fewer components integrated, and significantly decreased global modularity in the brain network. The MCI group had lower intra- and inter-lobular connectivity in all lobes. Between cerebral lobes, the MCI patients may maintain nodal connections between both hemispheres to reduce connectivity loss in the lateral hemispheres. The method and results presented in this study could be a suitable tool for early detection of MCI.

Use of focused computerized cognitive training (Neuroflex) to improve symptoms in women with persistent chemotherapy-related cognitive impairment

Purpose

Chemotherapy-related cognitive impairment (CRCI) is a distressing and increasingly recognized long-term sequela reported by breast cancer patients following cancer treatment. There is an urgent but unmet clinical need for treatments that improve CRCI. In this context, we proposed the use of a novel cognitive enhancement strategy called Neuroflex to target CRCI experienced by breast cancer survivors.

Methods

The primary aim of this pilot study was to evaluate the feasibility and acceptability of Neuroflex, a novel digital cognitive enhancement strategy, in breast and gynecologic cancer survivors with CRCI. Secondary analyses focused on whether improvements in performance on Neuroflex were associated with improvement in subjective cognitive complaints and objective cognitive performance measures.

Results

Participants (N = 21) completed an average of 7.42 hours of Neuroflex training per week, an average of 44.5 (±1.01) hours total, and had a 100% completion rate. Participants exhibited significant improvement in self-reported cognitive function as well as significant improvement on tasks of verbal learning and memory and auditory working memory. Participants also exhibited improvement in mood, as well as improvement on a disability assessment.

Conclusions

Results demonstrate feasibility and that breast cancer survivors are capable of completing a lengthy and challenging cognitive training program. Secondly, Neuroflex may confer specific cognitive benefits to both self-reported and objective performance. Results strongly support further investigation of Neuroflex in a larger controlled trial to establish efficacy for CRCI symptoms. Further studies may also result in optimization of this digital intervention for women with CRCI.

Longitudinal Assessment of Intravoxel Incoherent Motion Diffusion-Weighted MRI Metrics in Cognitive Decline

BACKGROUND

Advanced diffusion-based MRI biomarkers may provide insight into microstructural and perfusion changes associated with neurodegeneration and cognitive decline.

PURPOSE

To assess longitudinal microstructural and perfusion changes using apparent diffusion coefficient (ADC) and intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) parameters in cognitively impaired (CI) and healthy control (HC) groups.

STUDY TYPE

Prospective/longitudinal.

POPULATION

Twelve CI patients (75% female) and 13 HC subjects (69% female).

FIELD STRENGTH/SEQUENCE

3 T; Spin-Echo-IVIM-DWI.

ASSESSMENT

Two MRI scans were performed with a 12-month interval. ADC and IVIM-DWI metrics (diffusion coefficient [D] and perfusion fraction [f]) were generated from monoexponential and biexponential fits, respectively. Additionally, voxel-based correlations were evaluated between change in Montreal Cognitive Assessment (ΔMoCA) and baseline imaging parameters.

STATISTICAL TESTS

Analysis of covariance with sex and age as covariates was performed for main effects of group and time (false discovery rate [FDR] corrected) with post hoc comparisons using Bonferroni correction. Partial-η² and Hedges' g were used for effect-size analysis. Spearman's correlations (FDR corrected) were used for the relationship between ΔMoCA score and imaging. P < 0.05 was considered statistically significant.

RESULTS

Significant differences were found for the main effects of group (HC vs. CI) and time. For group effects, higher ADC, IVIM-D, and IVIM-f were observed in the CI group compared to HC (ADC: 1.23 ± 0.08^. 10^-3 vs. 1.09 ± 0.07^. 10^-3  mm² /sec; IVIM-D: 0.82 ± 0.01^. 10^-3 vs. 0.73 ± 0.01^. 10^-3  mm² /sec; and IVIM-f: 0.317 ± 0.008 vs. 0.253 ± 0.009). Significantly higher ADC, IVIM-D, and IVIM-f values were observed in the CI group after 12 months (ADC: 1.45 ± 0.05^. 10^-3 vs. 1.50 ± 0.07^. 10^-3  mm² /sec; IVIM-D: 0.87 ± 0.01^. 10^-3 vs. 0.94 ± 0.02^. 10^-3  mm² /sec; and IVIM-f: 0.303 ± 0.007 vs. 0.332 ± 0.008), but not in the HC group at large effect size. ADC, IVIM-D, and IVIM-f negatively correlated with ΔMoCA score (ρ = -0.49, -0.51, and -0.50, respectively).

DATA CONCLUSION

These findings demonstrate that longitudinal differences between CI and HC cohorts can be measured using IVIM-based metrics.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 2.

Efficacy and safety of hypoglycemic drugs in improving cognitive function in patients with Alzheimer's disease and mild cognitive impairment: A systematic review and network meta-analysis

OBJECTIVE

The purpose of this study was to compare the effects of oral hypoglycaemic drugs (HDs) on cognitive function and biomarkers of mild cognitive impairment (MCI) and Alzheimer's disease (AD) through a network meta-analysis of randomized controlled trials (RCTs).

METHODS

We conducted systematic searches for English- and Chinese-language articles in the PubMed, Medline, Embase, Cochrane Library and Google Scholar databases, with no date restrictions. We performed a network meta-analysis, which we report here according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The 16 studies included a total of 3,081 patients. We selected the Mini-Mental State Examination (MMSE), the Alzheimer's Disease Assessment Scale-Cognitive section (ADAS-Cog), the Alzheimer's Disease Cooperative Study Activities of Daily Living section (ADCS-ADL) and amyloid beta (Aβ) 42 as the outcome measures for analysis and comparison.

RESULT

We selected seven treatments and assessed the clinical trials in which they were tested against a placebo control. Of these treatments, intranasal insulin 20 IU (ITSN20), glucagon-like peptide-1 (GLP-1), and dipeptidyl peptidase 4 inhibitor (DPP-4) were associated with significantly improved MMSE scores (7 RCTs, 333 patients, 30≥MMSE score≥20: mild) compared with placebo [standardized mean difference (SMD) 1.11, 95% confidence interval (CI) (0.87, 1.35); SMD 0.75, 95% CI (0.04, 1.41); and SMD 4.08, 95% CI (3.39, 4.77), respectively]. Rosiglitazone 4 mg (RLZ4), rosiglitazone 10 mg (RLZ10), intranasal insulin 40 IU (ITSN40), and ITSN20 significantly decreased ADAS-Cog scores (11 RCTs, 4044 patients, 10 ≤ ADAS-Cog scores ≤ 30: mild and moderate) compared with placebo [SMD -1.40, 95% CI (-2.57, -0.23), SMD -3.02, 95% CI (-4.17, -1.86), SMD -0.92, 95% CI (-1.77, -0.08), SMD -1.88, 95% CI (-3.09, -0.66)]. Additionally, ITSN20 and ITSN40 significantly improved ADCS-ADL scores (2 RCTs, 208 patients, ADCS-ADL scale score ≤ 10: mild) compared with placebo [SMD 0.02, 95% CI (0.01, 0.03), and SMD 0.04, 95% CI (0.03, 0.05), respectively]. In the 16 included studies, the degree of AD was classified as mild or moderate. For mild cognitive impairment, DPP-4 performed best, but for mild to moderate impairment, ITSN40 had excellent performance.

CONCLUSION

Various HDs can improve the cognitive function of MCI and AD patients. Different drug regimens brought different degrees of improvement, which may be related to their dosage, duration, and mechanism of action.

SYSTEMATIC REVIEW REGISTRATION

www.crd.york.ac.uk/prospero.

Gender-specific prevalence and risk factors of mild cognitive impairment among older adults in Chongming, Shanghai, China

Objective

This study explores the gender differences in the prevalence of mild cognitive impairment (MCI) and the correlation between multiple influencing factors.

Materials and methods

The sample was comprised of 1325 relatively healthy participants aged ≥ 60 years in a Shanghai community-dwelling (557 males and 768 females). Cognitive function was assessed by Mini-Mental State Examination (MMSE). The Instrumental Activities of Daily Living (IADL) scale was used to assess the activities of daily living.

Results

The overall prevalence of MCI was 15.2%, with 10.2% in men and 18.9% in women. In older male subjects, those with higher the Geriatric Depression Scale (GDS) scores [odds ratio (OR) = 1.07, 95% confidence interval (CI) = 1.01–1.14] and hypertension (OR = 2.33, 95% CI = 1.15–4.73) had a higher risk of MCI. female subjects who were illiterate (OR = 2.95, 95% CI = 1.82–4.78), had a farming background (OR = 1.69, 95% CI = 1.05–2.72), and a history of stroke (OR = 1.96, 95% CI = 1.07–3.59) had a higher risk of MCI, but this was not true for males. However, Male subjects who never smoked were less likely to have MCI (OR = 0.22, 95% CI = 0.09–0.54). Additionally, the prevalence of MCI was lower in older women with high grip strength (OR = 0.96, 95% CI = 0.92–0.99) and hyperlipidemia (OR = 0.45, 95% CI = 0.22–0.96).

Conclusion

The prevalence of MCI was higher in the population of elderly women compared to men. Moreover, it was found that members with MCI tended to having higher GDS scores, smoking, and hypertension; whereas a history of farming, illiteracy, stroke, grip strength, and hyperlipidemia were correlated with MCI in women.

Use of machine learning to identify functional connectivity changes in a clinical cohort of patients at risk for dementia

Objective

Progressive conditions characterized by cognitive decline, including mild cognitive impairment (MCI) and subjective cognitive decline (SCD) are clinical conditions representing a major risk factor to develop dementia, however, the diagnosis of these pre-dementia conditions remains a challenge given the heterogeneity in clinical trajectories. Earlier diagnosis requires data-driven approaches for improved and targeted treatment modalities.

Methods

Neuropsychological tests, baseline anatomical T1 magnetic resonance imaging (MRI), resting-state functional MRI (rsfMRI), and diffusion weighted scans were obtained from 35 patients with SCD, 19 with MCI, and 36 age-matched healthy controls (HC). A recently developed machine learning technique, Hollow Tree Super (HoTS) was utilized to classify subjects into diagnostic categories based on their FC, and derive network and parcel-based FC features contributing to each model. The same approach was used to identify features associated with performance in a range of neuropsychological tests. We concluded our analysis by looking at changes in PageRank centrality (a measure of node hubness) between the diagnostic groups.

Results

Subjects were classified into diagnostic categories with a high area under the receiver operating characteristic curve (AUC-ROC), ranging from 0.73 to 0.84. The language networks were most notably associated with classification. Several central networks and sensory brain regions were predictors of poor performance in neuropsychological tests, suggesting maladaptive compensation. PageRank analysis highlighted that basal and limbic deep brain region, along with the frontal operculum demonstrated a reduction in centrality in both SCD and MCI patients compared to controls.

Conclusion

Our methods highlight the potential to explore the underlying neural networks contributing to the cognitive changes and neuroplastic responses in prodromal dementia.

Green tea improves cognitive function through reducing AD-pathology and improving anti-oxidative stress capacity in Chinese middle-aged and elderly people

Background: Numerous benefits of green tea have been reported. However, the effects of green tea on cognitive function remain disputable and the mechanism is still unclear.

Objective: To investigate the relationship of green tea consumption with cognitive function and related blood biomarkers among Chinese middle-aged and elderly people.

Methods: A total of 264 participants aged 50–70 years old were enrolled from Zhongnan Hospital of Wuhan University. They were interviewed about green tea consumption patterns and underwent neuropsychological tests covering five main cognitive domains to assess cognition including Montreal Cognitive Assessment (MoCA) and the other 10 scales. Then we detected serum oxidative stress biomarkers including Superoxide Dismutase (SOD), Malondialdehyde (MDA), Glutathione Peroxidase (GPx), Glutathione Reductase (GR), and Alzheimer’s disease (AD) markers including β-amyloid (Aβ)₄₀, Aβ₄₂, and phosphorylated tau-181 (pTau₁₈₁).

Results: In the tea-consuming group, the MoCA scores (P = 0.000), Hopkins Verbal Learning Test (HVLT) immediate recall (P = 0.012) and delayed recall (P = 0.013) were significantly higher while Trail Making Test-B (P = 0.005) and Victoria Stroop test interference (P = 0.000) were lower. In terms of oxidative stress markers, the tea-consuming group had lower serum MDA levels (P = 0.002) and higher serum SOD (P = 0.005) and GPx (P = 0.007) levels. In terms of AD markers, serum pTau₁₈₁ (P < 0.000), Aβ₄₂ (P = 0.019) and total Aβ levels (P = 0.034) but not serum Aβ₄₀ levels, were lower in the tea-consuming group. In the logistic regression analysis, there was a significant negative correlation between green tea consumption and cognitive impairment (OR = 0.26, 95 % CI 0.13 0.52 for high group).

Conclusion: Regular green tea consumption is associated with better cognitive function among Chinese middle-aged and elderly people, mainly reflected in memory and executive function. It may achieve protective effects by reducing AD-related pathology and improving anti-oxidative stress capacity and higher levels of tea consumption have a stronger protective effect.

Effect of Moxibustion Treatment on Degree Centrality in Patients With Mild Cognitive Impairment: A Resting-State Functional Magnetic Resonance Imaging Study

Background

Mild cognitive impairment (MCI) is a common neurological disorder. Moxibustion has been shown to be effective in treating MCI, but its therapeutic mechanisms still remain unclear. This study mainly aimed to investigate the modulation effect of moxibustion treatment for patients with MCI by functional magnetic resonance imaging (fMRI).

Methods

A total of 47 patients with MCI and 30 healthy controls (HCs) participated in resting-state fMRI imaging (rs-fMRI) scans. Patients with MCI were randomly divided into true moxibustion group (TRUE, n = 30) and sham moxibustion group (SHAM, n = 17). The degree centrality (DC) approach was applied to distinguish altered brain functions. Correlation analysis was then performed to examine the relationships between the neuroimaging findings and clinical symptoms.

Results

Compared with HCs, patients with MCI mainly showed decreased DC in the left middle frontal cortex (MFC) and bilateral middle cingulate cortex (MCC). After moxibustion treatment, the SHAM group had no significant DC findings, while TRUE group mainly showed significant increased DC in the bilateral MFC and MCC, as well as decreased DC in the left middle occipital cortex (MOC). Repeated measures analysis of variance (ANOVA) showed significant interactions between the two groups of patients with MCI. In addition, the higher Mini-Mental State Examination (MMSE) score was significantly positively correlated with increased DC in the right MFC and left MCC after moxibustion treatment.

Conclusion

Our findings demonstrate that the potential value of moxibustion treatment on MCI, which adds new insights into the popular view that moxibustion treatment may slow cognitive decline in patients with MCI.

Effect of hearing loss on cognitive function in patients with mild cognitive impairment: A prospective, randomized, and controlled study

Background

Hearing loss (HL) may increase the risk of cognitive decline in the elderly. However, the randomized controlled study on the effect of HL on cognitive function in mild cognitive impairment (MCI) is very limited.

Methods

From 1 November 2020 to 30 March 2022, 1,987 individuals aged 55–65 years were randomly divided into the MCI with hearing impairment (MCI-HI), MCI without HI (MCI-nHI), and no MCI (nMCI) groups by stratified sampling, with 30 participants in each group. The Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA), the pure tone audiometry (PTA), and the auditory brainstem response (ABR) were measured at baseline and a follow-up 12 months later. The trial protocol was registered with ClinicalTrials.gov with the registration number NCT05336942.

Results

Among the 90 participants, the average age was 60.41 ± 6.48 years. In the MCI-HI group at baseline, the PTA score of both the ears was negatively correlated with the naming and memory score (p < 0.05), and the PTA score of both the ears was negatively correlated with the MoCA and abstraction score at the 12-month follow-up (p < 0.05). However, there were no significant differences among the PTA, the ABR, the MMSE, and the MoCA scores in the MCI-nHI and nMCI groups (p > 0.05). Regression analysis showed that the PTA score of the right ear at baseline was an important factor associated with the MoCA, visuospatial/executive, naming, and abstraction scores at the 12-month follow-up (β = −0.776 to −0.422, p < 0.05).

Conclusion

HL was significantly negatively associated with cognitive function only in patients with MCI with hearing impairment (HI), and the PTA of the right ear may be a predictor of cognitive decline after 1 year in patients with MCI with HI. This information may help primary healthcare clinicians to prevent MCI by screening and intervening in care for elderly patients with HL.

Dance therapy and cognitive impairment in older people: A review of clinical data

ABSTRACT The growing interest for nonpharmacological treatment alternatives to older people with mild cognitive impairment or dementia has increased exponentially for the past few years; in this context, dance therapy is an effective therapeutic tool in improving the cognition of older people. The aim of this study was to verify whether dance therapy is a viable tool in promoting benefits with regard to the cognition and mood of older people with cognitive impairment. A database search covering the past 10 years was carried out. Result: The search found 193 papers; after title, abstract, and duplicity analysis, 14 of those were selected, of which 10 were fully revised. The studies showed positive results regarding the improvement of cognitive function after dance stimulations, as well as beneficial effects on the mood of older people with cognitive impairment.

Mild Cognitive Impairment in Rural Areas: Research Advances and Implications for Clinical Practice and Healthcare Policy

Mild cognitive or neurocognitive impairment (MCI) may be more prevalent in rural areas. Differences between rural and urban MCI patients in terms of risk factors, course and prognosis are rarely reported. The present review aims to summarize the latest research on MCI in rural areas. A literature search was performed in the databases of PubMed, Scopus and ScienceDirect for articles published over the last decade. Eleven articles were included in this review, reporting on the differences between rural and urban MCI patients. Several risk factors, such as older age, lack of activities and food insecurity have been associated with MCI in both rural and urban areas, whereas others, such as obesity, adverse childhood experiences and plasma chemokine C-C motif ligand 11 (considered as a potential negative regulator of neurogenesis), differed according to the place of residence. No specific protective factor for rural women has been reported. There is some evidence that MCI may present earlier in rural residents, but that progression to dementia may be more rapid in urban residents. It seems that there may be clinically relevant differences in the onset, course and prognosis of MCI with regards to the place of residence (urban vs rural). Those differences should be taken into account for the design of health policies and service delivery across different settings.

Monitoring mild cognitive impairment of workers exposed to occupational aluminium based on quantitative susceptibility mapping

AIM

To investigate the diagnostic value of quantitative susceptibility mapping (QSM) in mild cognitive impairment (MCI) of aluminium (Al) workers.

MATERIALS AND METHODS

The basic data of 53 workers in an Al factory were collected and divided into the MCI group and normal control (NC) group by Montreal Cognitive Assessment (MoCA) scores. All participants were tested for plasma Al concentration and had magnetic resonance imaging (MRI). The QSM values of many areas of the brain were delineated and measured. Independent two-sample t-tests or non-parametric tests were used to compare the parameter values between the two groups. Spearman's correlation analysis was performed between QSM values, MoCA scores, and plasma Al concentration. The receiver operating characteristic curve and z test were performed to assess diagnostic efficacy and the best parameter.

RESULTS

There was no difference in age and educational level. Plasma Al concentration of the MCI group was higher than that of NC group (p=0.057). QSM values of the left hippocampus, left dentate nucleus, right substantia nigra, and left putamen in MCI group were higher than that of NC group (p<0.05), and the left hippocampus had the best diagnostic efficacy. QSM values correlated negatively with MoCA scores. No correlation was found between QSM values and plasma Al concentration (p>0.05).

CONCLUSION

QSM might be a neuroimaging marker for the diagnosis of MCI. The left hippocampus showed the best diagnostic efficacy. Plasma Al concentration of the MCI group was higher than that of the NC group. A correlation between QSM and plasma Al concentration was not found.

Machine Learning Decomposition of the Anatomy of Neuropsychological Deficit in Alzheimer’s Disease and Mild Cognitive Impairment

Objective

Alzheimer’s Disease (AD) is a progressive condition characterized by cognitive decline. AD is often preceded by mild cognitive impairment (MCI), though the diagnosis of both conditions remains a challenge. Early diagnosis of AD, and prediction of MCI progression require data-driven approaches to improve patient selection for treatment. We used a machine learning tool to predict performance in neuropsychological tests in AD and MCI based on functional connectivity using a whole-brain connectome, in an attempt to identify network substrates of cognitive deficits in AD.

Methods

Neuropsychological tests, baseline anatomical T1 magnetic resonance imaging (MRI), resting-state functional MRI, and diffusion weighted imaging scans were obtained from 149 MCI, and 85 AD patients; and 140 cognitively unimpaired geriatric participants. A novel machine learning tool, Hollow Tree Super (HoTS) was utilized to extract feature importance from each machine learning model to identify brain regions that were associated with deficit and absence of deficit for 11 neuropsychological tests.

Results

11 models attained an area under the receiver operating curve (AUC-ROC) greater than 0.65, while five models had an AUC-ROC ≥ 0.7. 20 parcels of the Human Connectome Project Multimodal Parcelation Atlas matched to poor performance in at least two neuropsychological tests, while 14 parcels were associated with good performance in at least two tests. At a network level, most parcels predictive of both presence and absence of deficit were affiliated with the Central Executive Network, Default Mode Network, and the Sensorimotor Networks. Segregating predictors by the cognitive domain associated with each test revealed areas of coherent overlap between cognitive domains, with the parcels providing possible markers to screen for cognitive impairment.

Conclusion

Approaches such as ours which incorporate whole-brain functional connectivity and harness feature importance in machine learning models may aid in identifying diagnostic and therapeutic targets in AD.

How Do Older Adults Process Icons in Visual Search Tasks? The Combined Effects of Icon Type and Cognitive Aging

Considering the differences in cognitive aging among older adults, this study examined how older adults process different types of graphic icons in visual search tasks. Fifty-four medical-related icons, including flat icons (FIs), FIs plus text (FIs + text), skeuomorphic icons (SIs), and SIs plus text (SIs + text), were created. The participants were divided into two groups—cognitively normal (CN) and mild cognitive impairment (MCI)—to complete a visual search task. According to the eye-tracking data of the participants, the search performance of the CN group was significantly better than that of the MCI group. In terms of icon types, all older adults performed better at searching for the combinations of icon and text, especially SI + text, which showed the smallest difference in the search performance between the MCI and CN groups. All older adults performed poorly when searching for FIs. The findings of this study considered the differences in cognitive aging among older adults and provided a useful reference for the icon and interface design of graphical user interfaces.

The Association of Plasma Amyloid-β and Cognitive Decline in Cognitively Unimpaired Population

Purpose

This study investigates the relationship between baseline plasma Aβ and cognitive decline during follow-up in cognitively unimpaired population.

Materials and Methods

Cognitively unimpaired population was selected from people who lived in the suburbs of Xi’an, China. The levels of plasma Aβ_1-42 and Aβ_1-40 were tested using commercial enzyme-linked immunosorbent assay (ELISA). The mini-mental state examination (MMSE) and neuropsychological battery were used to assess cognition. Two years later, MMSE was tested again, and significant cognitive decline was defined as a decrease in MMSE scores ≥5 points. Logistic regression analysis was performed to analyze the relationship between baseline plasma Aβ and cognitive change during the two-year follow-up.

Results

A total of 1144 participants completed the study, among whom 59 subjects (5.2%) presented significant cognitive decline. The high plasma Aβ_1-42 level group had more significant cognitive decline (P = 0.023). Multivariable logistic regression analysis showed that significant cognitive decline was associated with the high levels of baseline plasma Aβ_1-42 (OR = 1.043, 95% CI: 1.005–1.083, P = 0.026). However, significant cognitive decline was not associated with baseline plasma Aβ_1-40 levels and Aβ_1-42 /Aβ_1-40 ratio.

Conclusion

Population with high level of baseline plasma Aβ_1-42 manifested significant cognitive decline over 2 years; however, further investigation on the dynamics of plasma Aβ and long-term follow-up are needed.

Virtual Reality Technology in Cognitive Rehabilitation Application: A Bibliometric Analysis (Preprint)

Background

In recent years, with the development of computer science and medical science, virtual reality (VR) technology has become a promising tool for improving cognitive function. Research on VR-based cognitive training has garnered increasing attention.

Objective

This study aimed to investigate the application status, research hot spots, and emerging trends of VR in cognitive rehabilitation over the past 20 years.

Methods

Articles on VR-based cognitive rehabilitation from 2001 to 2021 were retrieved from the Web of Science Core Collection. CiteSpace software was used for the visual analysis of authors and countries or regions, and Scimago Graphica software was used for the geographic visualization of published countries or regions. Keywords were clustered using the gCLUTO software.

Results

A total of 1259 papers were included. In recent years, research on the application of VR in cognitive rehabilitation has been widely conducted, and the annual publication of relevant literature has shown a positive trend. The main research areas include neuroscience and neurology, psychology, computer science, and rehabilitation. The United States ranked first with 328 papers, and Italy ranked second with 140 papers. Giuseppe Riva, an Italian academic, was the most prolific author with 29 publications. The most frequently cited reference was “Using Reality to Characterize Episodic Memory Profiles in Amnestic Mild Cognitive Impairment and Alzheimer’s Disease: Influence of Active and Passive Encoding.” The most common keywords used by researchers include “virtual reality,” “cognition,” “rehabilitation,” “performance,” and “older adult.” The largest source of research funding is from the public sector in the United States.

Conclusions

The bibliometric analysis provided an overview of the application of VR in cognitive rehabilitation. VR-based cognitive rehabilitation can be integrated into multiple disciplines. We conclude that, in the context of the COVID-19 pandemic, the development of VR-based telerehabilitation is crucial, and there are still many problems that need to be addressed, such as the lack of consensus on treatment methods and the existence of safety hazards.

Influence of the Microbiota-Gut-Brain Axis on Cognition in Alzheimer’s Disease

The gut microbiota is made up of trillions of microbial cells including bacteria, viruses, fungi, and other microbial bodies and is greatly involved in the maintenance of proper health of the host body. In particular, the gut microbiota has been shown to not only be involved in brain development but also in the modulation of behavior, neuropsychiatric disorders, and neurodegenerative diseases including Alzheimer’s disease. The precise mechanism by which the gut microbiota can affect the development of Alzheimer’s disease is unknown, but the gut microbiota is thought to communicate with the brain directly via the vagus nerve or indirectly through signaling molecules such as cytokines, neuroendocrine hormones, bacterial components, neuroactive molecules, or microbial metabolites such as short-chain fatty acids. In particular, interventions such as probiotic supplementation, fecal microbiota transfer, and supplementation with microbial metabolites have been used not only to study the effects that the gut microbiota has on behavior and cognitive function, but also as potential therapeutics for Alzheimer’s disease. A few of these interventions, such as probiotics, are promising candidates for the improvement of cognition in Alzheimer ’s disease and are the focus of this review.

Cerebrospinal Fluid Amino Acid Metabolite Signatures of Diabetic Cognitive Dysfunction Based on Targeted Mass Spectrometry

BACKGROUND

Diabetic cognitive dysfunction (DCD) is one of severe diabetic complications and might develop to irreversible dementia. Early diagnosis and detection of DCD is significant for prevention and treatment.

OBJECTIVE

The main objective of this study was to investigate the amino acid profiles of rat with DCD in the cerebrospinal fluid (CSF) to distinguish the early specific biomarkers.

METHODS

In total, rats were assigned into control and model groups. Model was induced by intraperitoneal injection of streptozotocin. The Morris water maze (MWM) method was used to evaluate learning and memory in rats on the 13th week after the model established. CSF samples were collected via cisterna magna puncture at the 0th, 5th, 9th, and 13th week, and amino acids profiling of CSF samples were performed via ultra performance liquid chromatography multiple reaction monitoring mass spectrometry (UPLC-MRM-MS). The amino acid profile was processed through multivariate analysis to identify potential biomarkers, and the related metabolic pathways were analyzed by MetaboAnalyst 5.0.

RESULTS

Compared to the control group, the escape latency of the MWM was significantly prolonged in model group rats (p <  0.05). Different amino acid profiles were obtained between two groups. L-Alanine, L-Glutamine, L-Lysine, L-Serine, and L-Threonine were identified as potential biomarkers for DCD. These biomarkers are principally involved in glycine, serine, and threonine metabolism, aminoacyl-tRNA biosynthesis, alanine, aspartate, and glutamate metabolism, and glyoxylate and dicarboxylate metabolism.

CONCLUSION

There are amino acid biomarkers in the CSF of rat with DCD. The mechanism of DCD is related to those pathways, which provide help for the early diagnosis and treatment and mechanism research.

Pulmonary Function in Midlife as a Predictor of Later-Life Cognition: The Coronary Artery Risk Development in Adults (CARDIA) Study

BACKGROUND

Studies found associations between pulmonary function (PF) and cognition, but these are limited by mostly cross-sectional design and a single measure of PF (typically forced expiratory volume in 1 second [FEV1]). Our objective was to prospectively analyze the association of repeatedly measured PF with cognition.

METHODS

We studied 3 499 participants in the Coronary Artery Risk Development in Young Adults cohort with cognition measured at year 25 (Y25) and Y30, and PF (FEV1 and forced vital capacity [FVC], reflecting better PF) measured up to 6 times from Y0 to Y20. Cognition was measured via Stroop test, Rey-Auditory Verbal Learning Test [RAVLT], and digit symbol substitution test [DSST], which capture executive function, verbal learning and memory, and attention and psychomotor speed, respectively; lower Stroop, and higher RAVLT and DSST scores indicate better cognition. We modeled linear, cross-sectional associations between cognition and PF at Y30 (mean age 55), and mixed models to examine associations between cognition at Y25-Y30 and longitudinal PF (both annual rate of change, and cumulative PF from Y0 to Y20).

RESULTS

At Y30, FEV1 and FVC were cross-sectionally associated with all 3 measures of cognition (β = 0.08-0.12, p < .01-.02). Annual change from peak FEV1/FVC ratio was associated with Stroop and DSST (β = 18.06, 95% CI = 7.71-28.40; β = 10.30, 95% CI = 0.26-20.34, respectively), but not RAVLT. Cumulative FEV1 and FVC were associated with Stroop and DSST (β = 0.07-0.12, p < .01-.02), but only cumulative FEV1 was associated with RAVLT (β = 0.07, 95% CI = 0.00-0.14).

CONCLUSIONS

We identified prospective associations between measures of PF and cognition even at middle ages, adding evidence of a prospective association between reduced PF and cognitive decline.