Memory impairment and Alzheimer's disease pathology in individuals with MCI who underestimate or overestimate their decline

Correlative factors of poor prognosis and abnormal cellular immune function in patients with Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is a serious disease causing human dementia and social problems. The quality of life and prognosis of AD patients have attracted much attention. The role of chronic immune inflammation in the pathogenesis of AD is becoming more and more important.

AIM

To study the relationship among cognitive dysfunction, abnormal cellular immune function, neuroimaging results and poor prognostic factors in patients.

METHODS

A retrospective analysis of 62 hospitalized patients clinical diagnosed with AD who were admitted to our hospital from November 2015 to November 2020. Collect cognitive dysfunction performance characteristics, laboratory test data and neuroimaging data from medical records within 24 h of admission, including Mini Mental State Examination Scale score, drawing clock test, blood T lymphocyte subsets, and neutrophils and lymphocyte ratio (NLR), disturbance of consciousness, extrapyramidal symptoms, electroencephalogram (EEG) and head nucleus magnetic spectroscopy (MRS) and other data. Multivariate logistic regression analysis was used to determine independent prognostic factors. the modified Rankin scale (mRS) was used to determine whether the prognosis was good. The correlation between drug treatment and prognostic mRS score was tested by the rank sum test.

RESULTS

Univariate analysis showed that abnormal cellular immune function, extrapyramidal symptoms, obvious disturbance of consciousness, abnormal EEG, increased NLR, abnormal MRS, and complicated pneumonia were related to the poor prognosis of AD patients. Multivariate logistic regression analysis showed that the decrease in the proportion of T lymphocytes in the blood after abnormal cellular immune function (odd ratio: 2.078, 95% confidence interval: 1.156-3.986, P < 0.05) was an independent risk factor for predicting the poor prognosis of AD. The number of days of donepezil treatment to improve cognitive function was negatively correlated with mRS score (r = 0.578, P < 0.05).

CONCLUSION

The decrease in the proportion of T lymphocytes may have predictive value for the poor prognosis of AD. It is recommended that the proportion of T lymphocytes < 55% is used as the cut-off threshold for predicting the poor prognosis of AD. The early and continuous drug treatment is associated with a good prognosis.

Quantitative morphometric changes in vascular mild cognitive impairment patients: early diagnosis of dementia

Vascular mild cognitive impairment (VMCI) is an early and reversible stage of dementia. Volume differences in regional gray matter may reveal the development and prognosis of VMCI. This study selected 2 of the most common types of VMCI, namely, periventricular white matter hyperintensities (PWMH, n = 14) and strategic single infarctions (SSI, n = 10), and used the voxel-based morphometry method to quantify their morphological characteristics. Meanwhile, age- and sex-matched healthy volunteers were included (n = 16). All the participants were neuropsychologically tested to characterize their cognitive function and underwent whole-brain magnetic resonance imaging scanning. Our results showed that the volumes of the bilateral temporal lobes and bilateral frontal gray matter were obviously diminished in the PWMH group. The atrophy volume difference was 4,086 voxels in the left temporal lobe, 4,154 voxels in the right temporal lobe, 1,718 voxels in the left frontal lobe, and 1,141 voxels in the right frontal lobe (P ≤ 0.001). Moreover, the characteristics of the gray matter atrophy associated with the PWMH were more similar to those associated with Alzheimer's disease than SSI, which further revealed the susceptibility for escalation from PWMH to dementia. In conclusion, PWMH patients and SSI patients have different morphological characteristics, which explain the different prognoses of VMCI.

Experiences and perceptions of health care professionals making treatment decisions for older adults with memory loss: a qualitative systematic review protocol

OBJECTIVE

The objective of this review is to critically analyze and synthesize the experiences and perceptions of health care professionals making decisions that result in treatment recommendations for older adults living with memory loss who are experiencing health problems.

INTRODUCTION

Health care professionals provide care to older adults living with memory loss and other coexisting health conditions across all clinical settings. Older adults living with memory loss most commonly experience impaired independent decision-making, which can challenge health care professionals when decisions about treatment need to be made. These challenges contribute to older adults with memory loss receiving inappropriate treatment and experiencing higher morbidity than those without memory loss. To date, existing reviews have not focused on the experiences and perceptions of health care professionals who are making treatment decisions when older adults living with memory loss experience health problems. A deeper exploration of this evidence is needed to understand health care professionals' experiences and perceptions of treatment decision-making to support the goal of improving care for older adults.

INCLUSION CRITERIA

This systematic review will consider studies across all clinical settings focused on the experiences and perceptions of health care professionals making treatment decisions for older adults with memory loss who are experiencing health problems.

METHODS

We will conduct a comprehensive systematic search using CINAHL, MEDLINE, PsycINFO, Scopus, and ProQuest Dissertations and Theses. Two reviewers will independently appraise the selected studies and extract qualitative data using the recommended JBI method for study selection, critical appraisal, data extraction, and data synthesis. The ConQual approach will be applied to provide a level of confidence for the review findings.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42021271485.

The Association Between Views of Aging and Subjective Cognitive Complaints in Older Adults: Findings From Two Samples

This cross-sectional study examined whether views of aging (VoA) relate to subjective cognitive complaints in two separate cohorts of older adults. Ageist attitudes, attitudes to aging (psychological loss, physical change, and psychological growth), subjective age, and subjective successful aging were examined. A moderating effect of chronological age was also examined. Samples included 572 adults aged 50 or older (Sample 1; mean age = 67.63, SD = 11.39, 49.4% female) and 224 adults aged 65 or older (Sample 2; mean age = 81.50, SD = 6.61, 75.3% female). More negative VoA (higher ageist attitudes, lower psychological growth, lower physical change, older subjective age, and less successful aging) were associated with more subjective cognitive complaints after controlling for covariates. An increase in chronological age strengthened some of these associations. Findings suggest that improving dimensions of VoA may have a complementary positive effect on subjective cognitive complaints in older adults.

Hyperconnectivity Associated with Anosognosia Accelerating Clinical Progression in Amnestic Mild Cognitive Impairment

The incidence and prevalence of anosognosia are highly variable in amnestic mild cognitive impairment (aMCI) patients. The study aims to explore the neuropathological mechanism of anosognosia in aMCI patients using two different but complementary technologies, including ¹⁸F-flortaucipir positron emission tomography and resting state functional magnetic resonance imaging. The study found that anosognosia was related to higher tau accumulation in the left medial orbitofrontal cortex (OFC), left posterior cingulate cortex, and right precuneus in aMCI patients. Intrinsic functional connectivity analyses found significant correlations between anosognosia index and hypoconnectivity between the left medial OFC and left middle temporal gyrus (MTG), right precuneus and left lingual gyrus. Longitudinally, the connectivity of these brain regions as well as the right precuneus and right cuneus showed hyperconnectivity in aMCI patients with anosognosia. The anosognosia index was also correlated with AD pathological markers (i.e., Aβ, t-tau, and p-tau) and brain glucose metabolism in aMCI patients. In conclusion, anosognosia in aMCI patients is associated with the dysfunction of medial OFC-MTG circuit and the precuneus-visual cortex circuit and accelerates clinical progression to AD dementia.

Deferoxamine preconditioning enhances the protective effects of stem cells in streptozotocin-induced Alzheimer's disease

AIMS

Stem cell-based therapy is one of the promising strategies in the treatment of Alzheimer's disease (AD), but the short lifespan and low homing of transplanted cells continue to be a major obstacle in this method. Preconditioning of stem cells before transplantation could increase cell therapy efficiency. Herein, we examined whether the treatment of stem cells with deferoxamine (DEF) prior to graft could enhance the neuroprotective effects of stem cells in the streptozotocin (STZ)-treated male rats.

MATERIALS AND METHODS

After induction of the AD model, the rats were transplanted with DEF-preconditioned Adipose-derived mesenchymal stem cells (AMSCs) or untreated cells. Memory function, antioxidant capacity, cell density, and homing of transplanted cells were assessed using Morris water maze and shuttle box tasks as well as biochemical and histochemical methods.

KEY FINDINGS

Transplantation of AMSCs caused a memory improvement when compared to the AD model. The injection of DEF-preconditioned AMSCs was more effective in improving learning and memory than the untreated cells through an increase in the antioxidant capacity. Moreover, the homing of transplanted cells was higher in the rats that received the preconditioned cells than that of the naïve cell-injected group.

SIGNIFICANCE

It seems that the transplantation of DEF-treated cells may increase the efficiency of stem cells via an increase in the antioxidant capacity.

Effects of Anosognosia on Static and Dynamic Amplitudes of Low-Frequency Fluctuation in Mild Cognitive Impairment

Background: Anosognosia is a significant symptom in patients with mild cognitive impairment (MCI) while the underlying neurological mechanism behind it is still unclear. Methods: A total of 121 subjects were included and classified into three groups, including 39 normal controls (NCs), 42 individuals with MCI without anosognosia (MCI-NA), and 40 individuals with MCI with anosognosia (MCI-A), based on their everyday cognition (ECog) questionnaire (discrepancy score). Resting-state functional MRIs were acquired from all the subjects, and the static amplitudes of low-frequency fluctuation (sALFF) and dynamic ALFF (dALFF) variance were investigated to evaluate the intrinsic functional network strength and stability, respectively, and both were corrected by age, sex, education, and gray matter volume. Eventually, correlation analyses were conducted to explore the relationship between brain activity changes and cognitive status in all the subjects. Results: No significant difference was found between MCI-A and MCI-NA (P > 0.05) in cognitive ability. Regarding intrinsic brain activity, MCI-A had increased sALFF and dALFF variance in the anterior cingulate cortex (ACC) relative to MCI-NA, as well as decreased sALFF and dALFF variance in the precuneus relative to MCI-NA and controls. Moreover, MCI-A had decreased sALFF in the inferior temporal gyrus (ITG) and paracentral lobule (PCL) compared to MCI-NA. Among all the subjects, correlation analyses showed that the sALFF and dALFF variance in the precuneus was related to the Ecog discrepancy score (r = 0.232 and 0.235, respectively), immediate story recall (r = 0.200 and 0.277, respectively), and delayed story recall (r = 0.255 and 0.298, respectively). Conclusion: Alterations of intrinsic brain activation in the ACC and precuneus seem to be associated with the anosognosia symptom in patients with MCI.

Early Alzheimer's disease diagnosis with the contrastive loss using paired structural MRIs

BACKGROUND AND OBJECTIVE

Alzheimer's Disease (AD) is a chronic and fatal neurodegenerative disease with progressive impairment of memory. Brain structural magnetic resonance imaging (sMRI) has been widely applied as important biomarkers of AD. Various machine learning approaches, especially deep learning-based models, have been proposed for the early diagnosis of AD and monitoring the disease progression on sMRI data. However, the requirement for a large number of training images still hinders the extensive usage of AD diagnosis. In addition, due to the similarities in human whole-brain structure, finding the subtle brain changes is essential to extract discriminative features from limited sMRI data effectively.

METHODS

In this work, we proposed two types of contrastive losses with paired sMRIs to promote the diagnostic performance using group categories (G-CAT) and varying subject mini-mental state examination (S-MMSE) information, respectively. Specifically, G-CAT contrastive loss layer was used to learn the closer feature representation from sMRIs with the same categories, while ranking information from S-MMSE assists the model to explore subtle changes between individuals.

RESULTS

The model was trained on ADNI-1. Comparison with baseline methods was performed on MIRIAD and ADNI-2. For the classification task on MIRIAD, S-MMSE achieves 93.5% of accuracy, 96.6% of sensitivity, and 94.9% of specificity, respectively. G-CAT and S-MMSE both reach remarkable performance in terms of classification sensitivity and specificity respectively. Comparing with state-of-the-art methods, we found this proposed method could achieve comparable results with other approaches.

CONCLUSION

The proposed model could extract discriminative features under whole-brain similarity. Extensive experiments also support the accuracy of this model, i.e., it provides better ability to identify uncertain samples, especially for the classification task of subjects with MMSE in 22-27. Source code is freely available at https://github.com/fengduqianhe/ADComparative.

Psychometric properties of the self-efficacy for managing mild cognitive impairment scale

OBJECTIVES

We adapted a self-efficacy measure for managing chronic illness to be specific to persons with mild cognitive impairment (pwMCI). The aim of this study was to investigate the psychometric properties of the scale, the self-efficacy for managing MCI scale, for use in research.

METHODS

Analyses involved data from pwMCI enrolled in a behavioral intervention study that completed the measure five times from intervention enrollment to 18-month post-intervention. Factor structure, construct validity, internal consistency, and test-retest reliability were analyzed.

RESULTS

Factor analysis identified two factors, related to self-efficacy for daily activities and managing MCI, which corresponded with domains from the original chronic illness self-efficacy scale. Consistent with prior research, construct validity analysis suggested an association between memory-loss self-efficacy and psychosocial distress, but not cognitive or functional ability. Further analyses supported the scale's internal and test-retest reliability.

CONCLUSIONS

Currently, no "gold standard" scale of memory-loss self-efficacy for pwMCI exists, despite the positive impact self-efficacy may have on modifiable health behaviors. Overall, results supported the notion that the scale is a valid and reliable measure of memory-loss self-efficacy for pwMCI.

Subjective cognitive and non-cognitive complaints and brain MRI biomarkers in the MEMENTO cohort

INTRODUCTION

Subjective cognitive complaints may be a signature of preclinical stage Alzheimer's disease. However, the link between subjective cognitive and non-cognitive complaints and brain alterations remains unclear.

METHODS

The relationship between cognitive and non-cognitive complaints and brain biomarkers, measured by structural magnetic resonance imaging, was investigated in 2056 participants of the MEMENTO cohort of outpatients, who were dementia-free at baseline. We assessed whether the cognitive status at inclusion or the presence of the apolipoprotein E gene variant (APOE) ε4 could modulate the association between the intensity of complaints and brain lesions.

RESULTS

Smaller hippocampal volume was associated with higher memory complaints and discomfort in daily life. In APOE ε4 carriers, smaller whole-brain white matter and gray matter volumes and gyrification indices in several regions of interest of the parietal and temporal lobes, in the entorhinal and the para-hippocampal gyrus, were associated with higher memory complaint score.

CONCLUSIONS

The intensity of subjective complaints in not only memory but discomfort in daily life was associated with brain degeneration markers. The presence of APOE ε4 modulated the relationships between subjective memory complaints and brain alterations.