2015 Alzheimer's disease facts and figures

Menopausal hormone therapy is associated with worse levels of Alzheimer's disease biomarkers in APOE ε4-carrying women: An observational study

INTRODUCTION

Menopausal hormone therapy (MHT), along with the apolipoprotein E (APOE) ε4 allele, has been suggested as a possible risk factor for Alzheimer's disease (AD). However, the relationship between MHT and cerebrospinal fluid (CSF) biomarkers is unknown: we investigated this association, and whether APOE ε4 carrier status moderates it.

METHODS

In an observational study of 136 cognitively unimpaired female participants (Mage = 66.0; standard deviation = 6.3), we examined whether MHT use alone or in interaction with APOE ε4 carrier status was associated with CSF levels of phosphorylated tau (p-tau), amyloid beta (Aβ)40, Aβ42, p-tau/Aβ42, and Aβ42/40 ratios.

RESULTS

Significant interactions were found between APOE ε4 and MHT use for CSF biomarkers. APOE ε4 carriers who were MHT users showed worse levels of CSF p-tau/Aβ42 and Aβ42/40 ratios than all other users and non-users.

DISCUSSION

The presence of both APOE ε4 and MHT may be associated with elevated amyloid deposition and AD pathology in this sample of participants who demonstrated high familial AD risk.

HIGHLIGHTS

Significant interactions were found between apolipoprotein E (APOE) ε4 and menopausal hormone therapy (MHT) use for cerebrospinal fluid (CSF) phosphorylated tau (p-tau)/amyloid beta (Aβ)42 and Aβ42/40 ratios. APOE ε4 carriers who were MHT users showed worse levels of CSF biomarkers than non-users and non-carriers, both users and non-users. Younger age at MHT initiation was associated with worse levels of the p-tau/Aβ42 and Aβ42/40 ratios in carriers only. The presence of both APOE ε4 carriage and MHT use may be associated with elevated amyloid deposition and AD pathology. Further studies with larger sample sizes are necessary to confirm the differences observed in the current study.

Sex differences in mitochondrial free-carnitine levels in subjects at-risk and with Alzheimer's disease in two independent study cohorts

A major challenge in the development of more effective therapeutic strategies for Alzheimer's disease (AD) is the identification of molecular mechanisms linked to specific pathophysiological features of the disease. Importantly AD has a two-fold higher incidence in women than men and a protracted prodromal phase characterized by amnestic mild-cognitive impairment (aMCI) suggesting that biological processes occurring early can initiate vulnerability to AD. Here, we used a sample of 125 subjects from two independent study cohorts to determine the levels in plasma (the most accessible specimen) of two essential mitochondrial markers acetyl-L-carnitine (LAC) and its derivative free-carnitine motivated by a mechanistic model in rodents in which targeting mitochondrial metabolism of LAC leads to the amelioration of cognitive function and boosts epigenetic mechanisms of gene expression. We report a sex-specific deficiency in free-carnitine levels in women with aMCI and early-AD compared to cognitively healthy controls; no change was observed in men. We also replicated the prior finding of decreased LAC levels in both women and men with AD, supporting the robustness of the study samples assayed in our new study. The magnitude of the sex-specific free-carnitine deficiency reflected the severity of cognitive dysfunction and held in two study cohorts. Furthermore, patients with the lower free-carnitine levels showed higher β-amyloid(Aβ) accumulation and t-Tau levels assayed in cerebrospinal fluid (CSF). Computational analyses showed that the mitochondrial markers assayed in plasma are at least as accurate as CSF measures to classify disease status. Together with the mechanistic platform in rodents, these translational findings lay the groundwork to create preventive individualized treatments targeting sex-specific changes in mitochondrial metabolism that may be subtle to early cognitive dysfunction of AD risk.

Recent advances in mRNA-based therapeutics for neurodegenerative diseases and brain tumors

Messenger RNA (mRNA) therapy is an innovative approach that delivers specific protein-coding information. By promoting the ribosomal synthesis of target proteins within cells, it supplements functional or antigenic proteins to treat diseases. Unlike traditional gene therapy, mRNA does not need to enter the cell nucleus, reducing the risks associated with gene integration. Moreover, protein expression levels can be regulated by adjusting the dosage and degradation rates of mRNA. As a new generation gene therapy strategy, mRNA therapy represents the latest advancements and trends in the field. It offers advantages such as precision, safety, and ease of modification. It has been widely used in the prevention of COVID-19. Unlike acute conditions such as cerebral hemorrhage and stroke that often require immediate surgical or interventional treatments, neurodegenerative diseases (NDs) and brain tumors progress relatively slowly and face challenges such as the blood-brain barrier and complex pathogenesis. These characteristics make them particularly suitable for mRNA therapy. With continued research, mRNA-based therapeutics are expected to play a significant role in the prevention and treatment of NDs and brain tumors. This paper reviews the preparation and delivery of mRNA drugs and summarizes the research progress of mRNA gene therapy in treating NDs and brain tumors. It also discusses the current challenges, providing a theoretical basis and reference for future research in this field.

Applying recommendations for diagnostic disclosure of mild cognitive impairment and dementia: Practical guidance for clinicians

A comprehensive evaluation for cognitive impairment should culminate with the communication of the diagnosis to patients and their care partners. This diagnostic disclosure sets the stage for subsequent care. Diagnostic disclosure for individuals with cognitive impairment due to Alzheimer's disease (AD) or AD-related dementias (ADRD) is particularly nuanced and requires a conscientious approach. Clinicians must assess patients' understanding and appreciation of symptoms, goals for the evaluation, and desire for information. Because AD/ADRD can impact patients' perceptions of their symptoms, it is recommended to include an informant or care partner for this assessment and for future care. Here, we provide guidance for addressing the complexities of AD/ADRD diagnostic disclosure to build clinicians' confidence in communicating diagnostic findings and a plan of care. HIGHLIGHTS: Diagnostic disclosure is a key part of the evaluation of cognitive impairment. The disclosure process begins at the moment a cognitive evaluation is initiated. Care partners must be included in the cognitive evaluation and diagnostic disclosure. Clinicians should use patient-centered communication for evaluation and disclosure.

fMRI-based Alzheimer's disease detection via functional connectivity analysis: a systematic review

Alzheimer's disease is a common brain disorder affecting many people worldwide. It is the primary cause of dementia and memory loss. The early diagnosis of Alzheimer's disease is essential to provide timely care to AD patients and prevent the development of symptoms of this disease. Various non-invasive techniques can be utilized to diagnose Alzheimer's in its early stages. These techniques include functional magnetic resonance imaging, electroencephalography, positron emission tomography, and diffusion tensor imaging. They are mainly used to explore functional and structural connectivity of human brains. Functional connectivity is essential for understanding the co-activation of certain brain regions co-activation. This systematic review scrutinizes various works of Alzheimer's disease detection by analyzing the learning from functional connectivity of fMRI datasets that were published between 2018 and 2024. This work investigates the whole learning pipeline including data analysis, standard preprocessing phases of fMRI, feature computation, extraction and selection, and the various machine learning and deep learning algorithms that are used to predict the occurrence of Alzheimer's disease. Ultimately, the paper analyzed results on AD and highlighted future research directions in medical imaging. There is a need for an efficient and accurate way to detect AD to overcome the problems faced by patients in the early stages.

Synthesis, Spectral Analysis and Molecular Docking Investigation of Thiadiazole Based Sulfonamide Derivatives: An Effective Approach Toward Alzheimer's Disease

Alzheimer's disease (AD), a neurodegenerative condition is expected to affect 152 million in 2050. The current study comprises the evaluation of thiazole based thiadiazole bearing sulfonamide derivatives to treat Alzheimer's disease. A series of compounds (1‐15) were synthesized and were studied for their anti‐Alzheimer's potential. Their IC50 values lie in the range between (19.20±0.20 nM–2.50±0.20 nM) for AChE and (19.80±0.20 nM–3.30±0.50 nM) for AChE. Among all of them, analog 2, 7, 9, and 15 were reported to possess significant activity. Among all the members of series, compound 15 having IC50=2.50±0.20 nM and 3.30±0.50 nM for AChE and BuChE, respectively, emerged as the most promising candidate due to the presence of two electronegative fluorine (F) atoms. The small and highly electronegative fluorine atoms have the ability to block the enzyme's activity by forming strong hydrogen bonds with the amino acids of the target enzymes, thereby inhibiting their function. The efficacy of these novel compounds was studied in comparison to the standard drug donepezil having IC50=5.80±0.30 nM for AChE and IC50=6.30±0.81 nM BuChE. For further assessment of inhibition potential and mode of inhibition, molecular docking study of all the potent compounds was carried out. Further, the structural identity of the synthesized compounds was confirmed using various spectroscopic techniques, including 1H‐NMR, 13C‐NMR, and High‐Resolution Electron Impact (HREI) Mass spectrometry, which provided detailed information about their molecular structure. ADME analysis of all the synthesized compounds confirmed their potential as drugs, indicating favorable pharmacokinetic properties and a promising drug profile.

Design and synthesis of phenoxy methyl-oxadiazole compounds against Alzheimer's disease

This study examines the synthesis and evaluation of 11 newly developed compounds as potential anti-Alzheimer's agents that occur via cholinesterase and β-secretase inhibition. The compounds were tested for their inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) using the modified Ellman method. The results showed that several compounds exhibited significant inhibition of AChE, particularly compounds 6d, 7a, and 7e, which demonstrated high inhibitory activity at lower concentrations, with IC50 values of 0.120, 0.039, and 0.063 µM, respectively. However, the compounds showed limited effectiveness against BChE, with only a few compounds exhibiting moderate inhibition. Compound 7e showed an inhibitory effect against BACE-1 close to that of the standard drug. Structural analysis revealed that the compounds with substituted benzothiazole and thiazole moieties exhibited the most promising inhibitory activity. This study provides valuable insights into the potential of these synthesized derivatives as a treatment against Alzheimer's disease. Moreover, the structure, stability, and properties of the active compounds were further investigated using density functional theory calculations. As a final note, the utilization of molecular docking and molecular dynamics simulation studies allowed us to elucidate the action mechanism of the active compounds and gain insights into the structure-activity relationship against AChE and β-secretase proteins. These computational techniques provide valuable information on the binding modes, interactions with target enzymes, dynamic behavior, and conformational changes of the compounds, enabling a comprehensive understanding of their biological activity.

EEG-Based Detection of Mild Cognitive Impairment Using DWT-Based Features and Optimization Methods

In recent years, electroencephalography (EEG) has been investigated for identifying brain disorders. This technique involves placing multiple electrodes (channels) on the scalp to measure the brain's activities. This study focuses on accurately detecting mild cognitive impairment (MCI) from the recorded EEG signals. To achieve this, this study first introduced discrete wavelet transform (DWT)-based approaches to generate reliable biomarkers for MCI. These approaches decompose each channel's signal using DWT into a set of distinct frequency band signals, then extract features using a non-linear measure such as band power, energy, or entropy. Various machine learning approaches then classify the generated features. We investigated these methods on EEGs recorded using 19 channels from 29 MCI patients and 32 healthy subjects. In the second step, the study explored the possibility of decreasing the number of EEG channels while preserving, or even enhancing, classification accuracy. We employed multi-objective optimization techniques, such as the non-dominated sorting genetic algorithm (NSGA) and particle swarm optimization (PSO), to achieve this. The results show that the generated DWT-based features resulted in high full-channel classification accuracy scores. Furthermore, selecting fewer channels carefully leads to better accuracy scores. For instance, with a DWT-based approach, the full-channel accuracy achieved was 99.84%. With only four channels selected by NSGA-II, NSGA-III, or PSO, the accuracy increased to 99.97%. Furthermore, NSGA-II selects five channels, achieving an accuracy of 100%. The results show that the suggested DWT-based approaches are promising to detect MCI, and picking the most useful EEG channels makes the accuracy even higher. The use of a small number of electrodes paves the way for EEG-based diagnosis in clinical practice.

Hormone therapy is associated with lower Alzheimer's disease tau biomarkers in post-menopausal females -evidence from two independent cohorts

BACKGROUND

Females represent approximately 70% of the Alzheimer's disease (AD) cases and the literature has proposed a connection between the decreased estrogen levels during menopause and an increased AD risk. Previous investigations have predominantly focused on assessing how hormone therapy (HT) affects the likelihood of AD development and cognitive deterioration. However, as the research framework has shifted toward a biomarker-defined AD and alterations in specific biomarkers could take place years before cognitive decline becomes discernible, it is crucial to examine how HT influences AD biomarkers. The main goal of this study was to evaluate the impact of HT on AD biomarker-informed pathophysiology in both cognitively unimpaired (CU) and cognitively impaired (CI) post-menopausal females across the aging and AD spectrum.

METHODS

This cross-sectional study included post-menopausal females without HT history (HT-) and with HT (HT+) at the time of PET imaging assessment from two cohorts: the Translational Biomarkers in Aging and Dementia (TRIAD) cohort, and the Alzheimer's Disease Neuroimaging Initiative (ADNI). Participants underwent magnetic resonance imaging (MRI), positron emission tomography (PET) and biofluid collection. Voxel-based t-tests were performed to assess the differences in amyloid-β (Aβ) and tau neurofibrillary tangles (NFTs) loads between HT- and HT + females. Linear regression models with interaction terms were also conducted to examine the interactive effects of HT and Aβ-PET on regional tau-PET.

RESULTS

HT + females demonstrated significantly lower tau-PET standardized uptake value ratio (SUVR) in Braak I-II ROIs (P < 0.05, Hedges' g = 0.73), Braak III-IV ROIs (P < 0.0001, Hedges' g = 0.74) and Braak V-VI ROIs (P < 0.0001, Hedges' g = 0.69) compared to HT- females. HT + females also showed significantly lower CSF p-tau181 (P < 0.001) and plasma p-tau181 (P < 0.0001) concentrations. Additionally, results from multivariate linear regression models indicated that HT interacts with cortical Aβ and is associated with lower regional NFT load.

CONCLUSIONS

Overall, findings from this observational study suggest that HT is associated with lower tau neuroimaging and fluid biomarkers in postmenopausal females. Due to the close link between tau and cognition, this study highlights the need for large randomized controlled trials designed to systemically study the influences of HT on AD biomarkers and disease progression.

Efficacy and safety of acupuncture for cognitive impairment in Alzheimer's disease: a systematic review and meta-analysis

Objective

To systematically evaluate the efficacy of acupuncture in the treatment of cognitive impairment in Alzheimer's disease (AD) by meta-analysis, in order to provide evidence-based evidence for the application of acupuncture therapy in the clinical process of AD.

Methods

From the establishment of the database to December 31, 2022, China Biomedical Literature Database (CBM), China National Knowledge Network (CNKI), VIP database, WanFang Database, Pubmed, Embase and Cochrane Library Database were systematically searched. To collect published randomized controlled clinical trials (RCTS) of acupuncture in the treatment of cognitive impairment in AD. The subjects in the intervention group were given acupuncture alone or combined with other treatments the same as the control group; the control group received conventional Western medicine treatment. The main outcome indicators of the study were cognitive function assessment of subjects, including: Simple Mental State Examination Scale (MMSE), Assessment of daily Living Ability Scale (ADL), Alzheimer's Disease Cognitive Function Assessment Scale (ADAS-Cog), TCM syndrome score (SDSD), Montreal Cognitive Test (MoCA), Secondary outcome indicators were the occurrence of adverse reactions. Literature screening, data extraction, and quality evaluation of the included literature were performed independently by two researchers, according to bias risk assessment tools recommended in the Cochrane manual. Data were analyzed by RevMan5.3 software. Dichotomous variables were represented by risk ratio (OR) and 95% CI, and continuity variables were represented by mean difference (MD) and 95% CI. For heterogeneity analysis, when P > 0.1 and I 2 ≤ 50%, fixed effect model was applied. When P ≤ 0.1 and I 2 > 50%, the random effects model is applied.

Results

A total of 1,172 eligible subjects were included in 18 RCTS, including 595 in the intervention group and 577 in the control group. The results of meta-analysis are as follows: acupuncture intervention group improved MMSE [MD = 1.67, 95% CI (0.94, 2.41), P < 0.00001], ADL [MD = -1.18, 95% CI (-3.09, 0.72), P = 0.22], ADAS-Cog [MD = 3.31, 95% CI (5.84, 0.78), P = 0.01], SDSD [MD = 2.40, 95% CI (3.53, 1.26), P < 0.0001], MoCA [MD = 4.80, 95% CI (3.74, 5.86), P = 0.04] were better than the control group. No serious adverse reactions related to acupuncture were observed in the intervention group, and the incidence and severity of adverse reactions were lower than those in the control group, with statistical significance [OR = 0.17, 95% CI (0.04, 0.67), P = 0.01].

Conclusion

Existing data show that acupuncture therapy has certain advantages in improving cognitive dysfunction and improving self-care ability of patients with Alzheimer's disease. However, due to the small number of RCTS and cases evaluating the efficacy of acupuncture, and the possibility of measurement bias and selectivity bias in included studies, it is still unable to conduct high-intensity demonstration on its effectiveness. Further large-scale, high-quality randomized, double-blind controlled trials are needed to evaluate its efficacy.

Systematic Review Registration

https://inplasy.com/inplasy-2021-12-0125/, identifier: INPLASY2021120125.

5α-Epoxyalantolactone from Inula macrophylla attenuates cognitive deficits in scopolamine-induced Alzheimer's disease mice model

Alzheimer's disease (AD) is a complex neurodegenerative condition. 5α-epoxyalantolactone (5α-EAL), a eudesmane-type sesquiterpene isolated from the herb of Inula macrophylla, has various pharmacological effects. This work supposed to investigate the improved impact of 5α-EAL on cognitive impairment. 5α-EAL inhibited the generation of nitric oxide (NO) in BV-2 cells stimulated with lipopolysaccharide (LPS) with an EC50 of 6.2 μM. 5α-EAL significantly reduced the production of prostaglandin E2 (PGE2) and tumor necrosis factor-α (TNF-α), while also inhibiting the production of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) proteins. The ability of 5α-EAL to penetrate the blood-brain barrier (BBB) was confirmed via a parallel artificial membrane permeation assay. Scopolamine (SCOP)-induced AD mice model was employed to assess the improved impacts of 5α-EAL on cognitive impairment in vivo. After the mice were pretreated with 5α-EAL (10 and 30 mg/kg per day, i.p.) for 21 days, the behavioral experiments indicated that the administration of the 5α-EAL could alleviate the cognitive and memory impairments. 5α-EAL significantly reduced the AChE activity in the brain of SCOP-induced AD mice. In summary, these findings highlight the beneficial effects of the natural product 5α-EAL as a potential bioactive compound for attenuating cognitive deficits in AD due to its pharmacological profile.

CSF amino acid profiles in ICV-streptozotocin-induced sporadic Alzheimer's disease in male Wistar rat: a metabolomics and systems biology perspective

Alzheimer's disease (AD) is an increasingly important public health concern due to the increasing proportion of older individuals within the general population. The impairment of processes responsible for adequate brain energy supply primarily determines the early features of the aging process. Restricting brain energy supply results in brain hypometabolism prior to clinical symptoms and is anatomically and functionally associated with cognitive impairment. The present study investigated changes in metabolic profiles induced by intracerebroventricular-streptozotocin (ICV-STZ) in an AD-like animal model. To this end, male Wistar rats received a single injection of STZ (3 mg·kg-1) by ICV (2.5 μL into each ventricle for 5 min on each side). In the second week after receiving ICV-STZ, rats were tested for cognitive performance using the Morris Water Maze test and subsequently prepared for positron emission tomography (PET) to confirm AD-like symptoms. Tandem Mass Spectrometry (MS/MS) analysis was used to detect amino acid changes in cerebrospinal fluid (CFS) samples. Our metabolomics study revealed a reduction in the concentrations of various amino acids (alanine, arginine, aspartic acid, glutamic acid, glycine, isoleucine, methionine, phenylalanine, proline, serine, threonine, tryptophane, tyrosine, and valine) in CSF of ICV-STZ-treated animals as compared to controls rats. The results of the current study indicate amino acid levels could potentially be considered targets of nutritional and/or pharmacological interventions to interfere with AD progression.

Pharmacist-led telehealth deprescribing for people living with dementia and polypharmacy in primary care: A pilot study

BACKGROUND

People living with dementia (PLWD) have complex medication regimens, exposing them to increased risk of harm. Pragmatic deprescribing strategies that align with patient-care partner goals are needed.

METHODS

A pilot study of a pharmacist-led intervention to optimize medications with patient-care partner priorities, ran May 2021-2022 at two health systems. PLWD with ≥7 medications in primary care and a care partner were enrolled. After an introductory mailing, dyads were randomized to a pharmacist telehealth intervention immediately (intervention) or delayed by 3 months (control). Feasibility outcomes were enrollment, intervention completion, pharmacist time, and primary care provider (PCP) acceptance of recommendations. To refine pragmatic data collection protocols, we assessed the Medication Regimen Complexity Index (MRCI; primary efficacy outcome) and the Family Caregiver Medication Administration Hassles Scale (FCMAHS).

RESULTS

69 dyads enrolled; 27 of 34 (79%) randomized to intervention and 28 of 35 (80%) randomized to control completed the intervention. Most visits (93%) took more than 20 min and required multiple follow-up interactions (62%). PCPs responded to 82% of the pharmacists' first messages and agreed with 98% of recommendations. At 3 months, 22 (81%) patients in the intervention and 14 (50%) in the control had ≥1 medication discontinued; 21 (78%) and 12 (43%), respectively, had ≥1 new medication added. The mean number of medications decreased by 0.6 (3.4) in the intervention and 0.2 (1.7) in the control, reflecting a non-clinically meaningful 1.0 (±12.4) point reduction in the MRCI among intervention patients and a 1.2 (±12.9) point increase among control. FCMAHS scores decreased by 3.3 (±18.8) points in the intervention and 2.5 (±14.4) points in the control.

CONCLUSION

Though complex, pharmacist-led telehealth deprescribing is feasible and may reduce medication burden in PLWD. To align with patient-care partner goals, pharmacists recommended deprescribing and prescribing. If scalable, such interventions may optimize goal-concordant care for PLWD.

Complicated Role of Post-translational Modification and Protease-Cleaved Fragments of Tau in Alzheimer's Disease and Other Tauopathies

Tau, a microtubule-associated protein predominantly localized in neuronal axons, plays a crucial role in promoting microtubule assembly, stabilizing their structure, and participating in axonal transport. Perturbations in tau's structure and function are implicated in the pathogenesis of neurodegenerative diseases collectively known as tauopathies, the most common disorder of which is Alzheimer's disease (AD). In tauopathies, it has been found that tau has a variety of post-translational modification (PTM) abnormalities and/or tau is cleaved into a variety of fragments by some specific proteolytic enzymes; however, the precise contributions of these abnormal modifications and fragments to disease onset and progression remain incompletely understood. Herein, we provide an overview about the involvement of distinctive abnormal tau PTMs and different tau fragments in the pathogenesis of AD and other tauopathies and discuss the involvement of proteolytic enzymes such as caspases, calpains, and asparagine endopeptidase in mediating tau cleavage while also addressing the intercellular transmission role played by tau. We anticipate that further exploration into PTMs and fragmented forms of tau will yield valuable insights for diagnostic approaches and therapeutic interventions targeting AD and other related disorders.

Neutrophil to lymphocyte ratio in Alzheimer's disease: A systematic review and meta-analysis

BACKGROUND

The Neutrophil-to-Lymphocyte Ratio (NLR) is a clinical indicator of peripheral inflammation that is easily accessible. It is worth noting that the formation of amyloid-β (Aβ) plaques and neurofibrillary tangles has been linked to inflammation and immune dysregulation. The main objective of this systematic review and meta-analysis is to comprehensively evaluate the existing body of research concerning the NLR in the context of Alzheimer's disease (AD) and mild cognitive impairment (MCI).

METHOD

We conducted a comprehensive online search and included studies that evaluated the NLR in 1) patients with AD or MCI and 2) healthy control (HC) participants. We also pooled mean and standard deviation (SD) data for each group.

RESULTS

Ultimately, 12 studies encompassed 1,309 individuals diagnosed with AD with mean NLR levels of 2.68, 1,929 individuals with MCI with mean NLR levels of 2.42, and 2,064 HC with mean NLR levels of 2.06 were included in this systematic review and meta-analysis. The mean NLR was 0.59 higher in AD patients compared to HC participants (mean difference (MD) = 0.59 [0.38; 0.80]). Similarly, the mean NLR was higher in AD than MCI patients (MD = 0.23 [0.13; 0.33]). Additionally, the mean NLR was higher in individuals with MCI compared to HC participants (MD = 0.37 [0.22; 0.52]). In the subgroup meta-analysis based on the Mini-Mental State Examination (MMSE), AD patients with lower MMSE scores (using a cut-off of 20) exhibited significantly higher mean NLR (3.10 vs. 2.70, with a p-value for subgroup differences < 0.01).

CONCLUSION

The NLR, which serves as a marker of peripheral inflammation, shows increased levels in individuals with AD and MCI compared to HC participants. Furthermore, our study indicates that NLR levels are significantly higher in AD than MCI. Additionally, our novel finding suggests significantly higher NLR levels among AD patients with more severe cognitive decline compared to AD patients with less severe cognitive decline. So, it can be concluded that the higher cognitive decline in humans is accompanied by higher NLR levels. Further longitudinal researches are needed to explore more details about the relationship between inflammation and dementia.

Investigation of hemispheric asymmetry in Alzheimer's disease patients during resting state revealed BY fNIRS

Alzheimer's disease (AD) is characterized by the gradual deterioration of brain structures and changes in hemispheric asymmetry. Meanwhile, healthy aging is associated with a decrease in functional hemispheric asymmetry. In this study, functional connectivity analysis was used to compare the functional hemispheric asymmetry in eyes-open resting-state fNIRS data of 16 healthy elderly controls (mean age: 60.4 years, MMSE (Mini-Mental State Examination): 27.3 ± 2.52) and 14 Alzheimer's patients (mean age: 73.8 years, MMSE: 22 ± 4.32). Increased interhemispheric functional connectivity was found in the premotor cortex, supplementary motor cortex, primary motor cortex, inferior parietal cortex, primary somatosensory cortex, and supramarginal gyrus in the control group compared to the AD group. The study revealed that the control group had stronger interhemispheric connectivity, leading to a more significant decrease in hemispheric asymmetry than the AD group. The results show that there is a difference in interhemispheric functional connections at rest between the Alzheimer's group and the control group, suggesting that functional hemispheric asymmetry continues in Alzheimer's patients.

Selecting EEG channels and features using multi-objective optimization for accurate MCI detection: validation using leave-one-subject-out strategy

Effective management of dementia requires the timely detection of mild cognitive impairment (MCI). This paper introduces a multi-objective optimization approach for selecting EEG channels (and features) for the purpose of detecting MCI. Firstly, each EEG signal from each channel is decomposed into subbands using either variational mode decomposition (VMD) or discrete wavelet transform (DWT). A feature is then extracted from each subband using one of the following measures: standard deviation, interquartile range, band power, Teager energy, Katz's and Higuchi's fractal dimensions, Shannon entropy, sure entropy, or threshold entropy. Different machine learning techniques are used to classify the features of MCI cases from those of healthy controls. The classifier's performance is validated using leave-one-subject-out (LOSO) cross-validation (CV). The non-dominated sorting genetic algorithm (NSGA)-II is designed with the aim of minimizing the number of EEG channels (or features) and maximizing classification accuracy. The performance is evaluated using a publicly available online dataset containing EEGs from 19 channels recorded from 24 participants. The results demonstrate a significant improvement in performance when utilizing the NSGA-II algorithm. By selecting only a few appropriate EEG channels, the LOSO CV-based results show a significant improvement compared to using all 19 channels. Additionally, the outcomes indicate that accuracy can be further improved by selecting suitable features from different channels. For instance, by combining VMD and Teager energy, the SVM accuracy obtained using all channels is 74.24%. Interestingly, when only five channels are selected using NSGA-II, the accuracy increases to 91.56%. The accuracy is further improved to 95.28% when using only 8 features selected from 7 channels. This demonstrates that by choosing informative features or channels while excluding noisy or irrelevant information, the impact of noise is reduced, resulting in improved accuracy. These promising findings indicate that, with a limited number of channels and features, accurate diagnosis of MCI is achievable, which opens the door for its application in clinical practice.

Natural Antioxidants: An Effective Strategy for the Treatment of Alzheimer's Disease at the Early Stage

The critical role of oxidative stress in Alzheimer's disease (AD) has been recognized by researchers recently, and natural antioxidants have been demonstrated to have anti-AD activity in animal models, such as Ginkgo biloba extract, soy isoflavones, lycopene, and so on. This paper summarized these natural antioxidants and points out that natural antioxidants always have multiple advantages which are help to deal with AD, such as clearing free radicals, regulating signal transduction, protecting mitochondrial function, and synaptic plasticity. Based on the available data, we have created a relatively complete pathway map of reactive oxygen species (ROS) and AD-related targets and concluded that oxidative stress caused by ROS is the core of AD pathogenesis. In the prospect, we introduced the concept of a combined therapeutic strategy, termed "Antioxidant-Promoting Synaptic Remodeling," highlighting the integration of antioxidant interventions with synaptic remodeling approaches as a novel avenue for therapeutic exploration.

Neuro-Adipokine Crosstalk in Alzheimer's Disease

The connection between body weight alterations and Alzheimer's disease highlights the intricate relationship between the brain and adipose tissue in the context of neurological disorders. During midlife, weight gain increases the risk of cognitive decline and dementia, whereas in late life, weight gain becomes a protective factor. Despite their substantial impact on metabolism, the role of adipokines in the transition from healthy aging to neurological disorders remains largely unexplored. We aim to investigate how the adipose tissue milieu and the secreted adipokines are involved in the transition between biological and pathological aging, highlighting the bidirectional relationship between the brain and systemic metabolism. Understanding the function of these adipokines will allow us to identify biomarkers for early detection of Alzheimer's disease and uncover novel therapeutic options.

Hybrid molecules synergistically mitigate ferroptosis and amyloid-associated toxicities in Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the build-up of extracellular amyloid β (Aβ) plaques and intracellular neurofibrillary tangles (NFTs). Ferroptosis, an iron (Fe)-dependent form of cell death plays a significant role in the multifaceted AD pathogenesis through generation of reactive oxygen species (ROS), mitochondrial damage, lipid peroxidation, and reduction in glutathione peroxidase 4 (GPX4) enzyme activity and levels. Aberrant liquid-liquid phase separation (LLPS) of tau drives the growth and maturation of NFTs contributing to AD pathogenesis. In this study, we strategically combined the structural and functional properties of gallic acid (GA) and cyclic dipeptides (CDPs) to synthesize hybrid molecules that effectively target both ferroptosis and amyloid toxicity in AD. This innovative approach marks a paradigm shift from conventional therapeutic strategies. This is the first report of a synthetic small molecule (GCTR) that effectively combats ferroptosis, simultaneously restoring enzymatic activity and enhancing cellular levels of its master regulator, GPX4. Further, GCTR disrupts Fe3+-induced LLPS of tau, and aids in attenuation of abnormal tau fibrillization. The synergistic action of GCTR in combating both ferroptosis and amyloid toxicity, bolstered by GPX4 enhancement and modulation of Fe3+-induced tau LLPS, holds promise for the development of small molecule-based novel therapeutics for AD.

Altered dynamic amplitude of low-frequency fluctuation in individuals at high risk for Alzheimer's disease

The brain's dynamic spontaneous neural activity is significant in supporting cognition; however, how brain dynamics go awry in subjective cognitive decline (SCD) and mild cognitive impairment (MCI) remains unclear. Thus, the current study aimed to investigate the dynamic amplitude of low-frequency fluctuation (dALFF) alterations in patients at high risk for Alzheimer's disease and to explore its correlation with clinical cognitive assessment scales, to identify an early imaging sign for these special populations. A total of 152 participants, including 72 SCD patients, 44 MCI patients and 36 healthy controls (HCs), underwent a resting-state functional magnetic resonance imaging and were assessed with various neuropsychological tests. The dALFF was measured using sliding-window analysis. We employed canonical correlation analysis (CCA) to examine the bi-multivariate correlations between neuropsychological scales and altered dALFF among multiple regions in SCD and MCI patients. Compared to those in the HC group, both the MCI and SCD groups showed higher dALFF values in the right opercular inferior frontal gyrus (voxel P < .001, cluster P < .05, correction). Moreover, the CCA models revealed that behavioural tests relevant to inattention correlated with the dALFF of the right middle frontal gyrus and right opercular inferior frontal gyrus, which are involved in frontoparietal networks (R = .43, P = .024). In conclusion, the brain dynamics of neural activity in frontal areas provide insights into the shared neural basis underlying SCD and MCI.

Art therapies and cognitive function in elderly with subjective cognitive decline: a protocol for a network meta-analysis

INTRODUCTION

Subjective cognitive decline means a decline in the subjective perception of self-cognitive function, which is likely to evolve into mild cognitive impairment and dementia. The number of elderly with subjective cognitive decline has increased, bringing huge burdens and challenges to caregivers and society. With the increase in research on art therapies, some of them have gradually been proven to be effective for cognitive function. Therefore, this study aims to summarise the evidence and identify the best art therapy for elderly with subjective cognitive decline.

METHODS AND ANALYSIS

We will include published randomised controlled trials written in English and Chinese if the intervention is one of the art therapies and applied in people aged 60 and above with subjective cognitive decline. Eight electronic databases, including the Cochrane Central Register of Controlled Trials, PubMed, Web of Science, Elsevier, China BioMedical Literature Database, China National Knowledge Infrastructure, VIP Database and Wanfang Database, will be searched from January 2013 to December 2023. Art therapies will mainly include music therapy, reminiscence therapy, painting therapy, dance therapy, reading therapy, horticultural therapy, museum therapy, calligraphy therapy and so on. The outcome will be cognitive function. Study selection, data extraction and quality assessment will be performed by two reviewers. The risk of bias will be evaluated according to the Cochrane Collaboration's risk-of-bias tool, and the evidence quality will be assessed with the Grading of Recommendations Assessment, Development and Evaluation. Standard pairwise meta-analysis and Bayesian network meta-analysis will be conducted. The probabilities of each art therapy will be ranked based on the surface under the cumulative ranking curve.

ETHICS AND DISSEMINATION

Ethical approval is not required for reviewing published studies. To provide important evidence for clinicians and guideline developers, the findings of this study will be submitted to a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42023443773.

Association between multimorbidity and cognitive decline in the elderly population of the Eastern Province, Saudi Arabia

BACKGROUND

Cognitive decline affects the quality of life, and dementia affects independence in daily life activities. Multimorbidity in older adults is associated with a higher risk of cognitive impairment. This research aims to study the relationship between cognitive decline and multimorbidity in the elderly population in the Eastern Province, Saudi Arabia.

MATERIALS AND METHODS

This cross-sectional research was conducted from July to October 2022 among adults over 60 years. All patients with two or more comorbidities were contacted for a face-to-face interview and cognitive testing to estimate cognitive function by trained family physicians using St. Louis University Mental State Examination. ANOVA and Chi-square test were used to test for statistical significance. Binary logistic regression was used to show the odds of having cognitive impairment and multimorbidity. All tests were performed at 5% level of significance.

RESULTS

The study involved 343 individuals; majority (74.1%) aged 60-75 years and were males (67.9%). Hypertension, diabetes, and chronic pain were reported by 56%, 48%, and 44% participants, respectively. Thirty percent participants had 3 or more comorbidities. About 36% had mild neurocognitive disorder and 31.2% had dementia. The results showed that age, gender (female), diabetes, stroke, chronic pain, and multimorbidity were significantly associated with cognitive impairment. In our study, hypertension, coronary artery diseases, depression, and anxiety were not significantly associated with risk of cognitive decline.

CONCLUSION

Our study found that multimorbidity is significantly associated with cognitive decline. Controlling comorbidities and preventing risk factors in midlife could help in delaying the progression of the disease.

Distance-weighted Sinkhorn loss for Alzheimer's disease classification

Traditional loss functions such as cross-entropy loss often quantify the penalty for each mis-classified training sample without adequately considering its distance from the ground truth class distribution in the feature space. Intuitively, the larger this distance is, the higher the penalty should be. With this observation, we propose a penalty called distance-weighted Sinkhorn (DWS) loss. For each mis-classified training sample (with predicted label A and true label B), its contribution to the DWS loss positively correlates to the distance the training sample needs to travel to reach the ground truth distribution of all the A samples. We apply the DWS framework with a neural network to classify different stages of Alzheimer's disease. Our empirical results demonstrate that the DWS framework outperforms the traditional neural network loss functions and is comparable or better to traditional machine learning methods, highlighting its potential in biomedical informatics and data science.

Graves disease is associated with increased risk of clinical Alzheimer's disease: evidence from the Medicare system

BACKGROUND

Identification of modifiable risk factors for Alzheimer's Disease (AD) onset is an important aspect of controlling the burden imposed by this disease on an increasing number of older U.S. adults. Graves disease (GD), the most common cause of hyperthyroidism in the U.S., has been hypothesized to be associated with increased AD risk, but there is no consensus. In this study, we explore the link between GD and risk of clinical AD.

METHODS

Cox and Fine-Grey models were applied to a retrospective propensity-score-matched cohort of 19,798 individuals with GD drawn from a nationally representative 5% sample of U.S. Medicare beneficiaries age 65 + over the 1991-2020 period.

RESULTS

Results showed that the presence of GD was associated with a higher risk of AD (Hazard Ratio [HR]:1.19; 95% Confidence Interval [CI]:1.13-1.26). Competing risk estimates were consistent with these findings (HR:1.14; CI:1.08-1.20) with the magnitude of associated risk varying across subgroups: Male (HR:1.25; CI:1.07-1.47), Female (HR:1.09; CI:1.02-1.16), White (HR:1.11; CI:1.03-1.19), and Black (HR:1.23; CI:1.02-1.49).

CONCLUSIONS

Our results indicate a robust and consistent association between a diagnosis of GD and a subsequent diagnosis of AD in later stages of life. The precise biological pathways that could potentially connect these two conditions remain unclear as is the role of treatment in this relationship. Replications of these findings on datasets with both biomarkers and laboratory test results, especially in underrepresented groups is vital.

Best Practices for Communicating a Diagnosis of Dementia: Results of a Multi-Stakeholder Modified Delphi Consensus Process

Background and Objectives

Many individuals with dementia and their families report not receiving a dementia diagnosis. Previously published standards for delivering a dementia diagnosis are now more than 10 years old and were developed without patient and caregiver input. The objective of this study was to identify best practices for delivering a diagnosis of dementia using existing literature, involvement of diverse stakeholders, and consensus building through a formal modified Delphi approach.

Methods

We convened a multi-stakeholder working group including a patient, caregivers, Alzheimer's Association staff, and clinicians from diverse backgrounds. The panel used the American Academy of Neurology process for recommendation development, consisting of a half-day workshop and 3 rounds of anonymous modified Delphi voting to achieve consensus.

Results

The working group convened from May 2022 through January 2023. The group chose to focus statements on a limited number of best practices that can be applied across clinic types. Seven best practice statements achieved consensus after a maximum of 3 rounds of voting. These included the following: (1) Clinicians must show compassion and empathy when delivering a diagnosis of dementia (level A). During dementia diagnosis disclosure, clinicians should (2) ask regarding diagnosis preferences, (3) instill realistic hope, (4) provide practical strategies, (5) provide education and connections to high-quality resources, (6) connect caregivers to support resources, and (7) provide written summaries of the diagnoses, plan, and relevant resources (each level B).

Discussion

Clinicians need to customize discussion of a dementia diagnosis for individual patients and their caregivers. These 7 best practices provide a diagnosis communication framework that can be implemented across varied clinical settings. Additional strategies, such as using optimal general communication approaches, are also important for dementia diagnosis discussions. Thoughtful application of these best practices is particularly important when caring for individuals from underrepresented communities. Further improving communication regarding dementia diagnoses will require health system changes (e.g., for sufficient time), improved access to specialty dementia care, and clinician training for delivering difficult diagnoses. More research is needed to identify culturally sensitive approaches to discussing dementia diagnoses.

Huannao Yicong decoction ameliorates cognitive deficits in APP/PS1/tau triple transgenic mice by interfering with neurotoxic interaction of Aβ-tau

ETHNOPHARMACOLOGICAL RELEVANCE

Huannao Yicong decoction (HYD) has been used in the study of AD for many years, which consists of Polygonum multiflorum Thunb., Panax ginseng C.A.Mey., Acorus gramineus Aiton, Coptis chinensis Franch., and Conioselinum acuminatum (Franch.) Lavrova. Previous studies have found that HYD could reduce β-Amyloid (Aβ) deposition and tau hyperphosphorylation which are the two critical pathological factors of AD. However, the mechanism of the neurotoxic interaction between Aβ and tau in AD remains unclear. Thus, the underlying mechanisms for HYD improving cognitive function of AD by interfering with the neurotoxic interaction between Aβ and tau remain to be explored.

AIM OF THE STUDY

The main objective of this study is to clarify the specific mechanisms of HYD on interfering with the neurotoxic interaction between Aβ and tau of AD both in vivo and in vitro.

MATERIALS AND METHODS

APP/PS1/tau triple transgenic mice were randomly divided into 4 groups, namely model group, memantine group, HYD low-dose group (HYD-L), and HYD high-dose group (HYD-H) with 28 mice in each group, while 28 C57BL/6J mice as the control group. Gavage was applied to all the mice daily for 24 weeks. SH-SY5Y model cells overexpressing Aβ and tau proteins as the intervention object in vitro experiments. Morris water maze was used to observe the learning and memory ability of APP/PS1/tau mice. Aβ deposition was detected by immunohistochemistry, and the levels of Aβ1-40 and Aβ1-42 were detected by enzyme-linked immunosorbent assay (ELISA). Neurofibrillary tangles (NFTs) were observed by silver staining and the levels of phosphorylated tau proteins were detected by Western blot. The GSK-3β and CDK-5 mRNA expression were detected by real-time polymerase chain reaction (RT-PCR). Besides, the levels of PSD95, GluR1, NR2A, and NR2B were detected by Western blot. Meanwhile, cell experiments were performed to further verify the effect of HYD on tau phosphorylation related kinases (GSK-3β, CDK-5, and PP2A), which further to clarify the mechanism of HYD intervention on the neurotoxic interaction between Aβ and tau.

RESULTS

HYD improved the learning and memory ability of APP/PS1/tau mice. HYD decreased the levels of Aβ1-40 and Aβ1-42 and inhibited tau hyperphosphorylation, which reduced Aβ deposition and NFTs forming. In addition, HYD inhibited the activity of kinases GSK-3β and CDK-5, and enhancing the activity of kinase PP2A. Moreover, HYD inhibited the overexpression of NR2A and NR2B, and increased the expression of GluR1 and postsynaptic density protein-95 (PSD95).

CONCLUSIONS

HYD can improve the cognitive deficits by interfering with the neurotoxic interaction between Aβ and tau. In addition, HYD can inhibit the overactivation of NMDARs and increase the levels of GluR1 and PSD95, which may play a role in alleviating neuronal excitotoxicity and improving synaptic function.

Towards privacy-preserving Alzheimer's disease classification: Federated learning on T1-weighted magnetic resonance imaging data

Objective

This study aims to address the challenge of privacy-preserving Alzheimer's disease classification using federated learning across various data distributions, focusing on real-world applicability. The goal is to improve the efficiency of classification by minimizing communication rounds between clients and the central server.

Methods

The proposed approach leverages two key strategies: increasing parallelism by utilizing more clients in each communication round and increasing computation per client during the intervals between rounds. To reflect real-world scenarios, data is divided into three distributions: identical and independently distributed, non-identical and independently distributed equal, and non-identical and independently distributed unequal. The impact of extreme quantity distribution skew is also examined. A convolutional neural network is used to evaluate the performance across these setups.

Results

The empirical study demonstrates that the proposed federated learning approach achieves a maximum accuracy of 84.75%, a precision of 86%, a recall of 85%, and an F1-score of 84%. Increasing the number of local epochs improves classification performance and reduces communication needs. The experiments show that federated learning is effective in handling heterogeneous datasets when all clients participate in each round of training. However, the results also indicate that extreme quantity distribution skew negatively impacts classification performance.

Conclusions

The study confirms that federated learning is a viable solution for Alzheimer's disease classification while preserving data privacy. Increasing local computation and client participation enhances classification performance, though extreme distribution imbalances present a challenge. Further investigation is needed to address these limitations in real-world scenarios.

Research Progress of Eye Movement Analyses and its Detection Algorithms in Alzheimer's Disease

Alzheimer's disease (AD) has been considered one of the most challenging forms of dementia. The earlier the people are diagnosed with AD, the easier it is for doctors to find a treatment. Based on the previous literature summarizing the research results on the relationship between eye movement and AD before 2013, this paper reviewed 34 original eye movements research papers only closely related to AD published in the past ten years and pointed out that the prosaccade (4 papers) and antisaccade (5 papers) tasks, reading tasks (3 papers), visual search tasks (3 papers) are still the research objects of many researchers, Some researchers have looked at King-Devick tasks (2 papers), reading tasks (3 papers) and special tasks (8 papers), and began to use combinations of different saccade tasks to detect the relationship between eye movement and AD, which had not been done before. These reflect the diversity of eye movement tasks and the complexity and difficulty of the relationship between eye movement and AD. On this basis, the current processing and analysis methods of eye movement datasets are analyzed and discussed in detail, and we note that certain key data that may be especially important for the early diagnosis of AD by using eye movement studies cannot be miss-classified as noise and removed. Finally, we note that the development of methods that can accurately denoise and classify and quickly process massive eye movement data is quite significant for detecting eye movements in early diagnosis of AD.

Exploring the Therapeutic Potential of Alkaloids in Alzheimer's Disease Management

BACKGROUND

Alkaloids are important phytoconstituents obtained from various plant sources. The study's primary goal is to assess the anti-Alzheimer potential of alkaloids using a molecular docking study. Alzheimer's disease (AD) is considered a gradual decline in memory, reasoning, decision-making, orientation to one's physical surroundings, and language.

MATERIALS AND METHODS

The main target i.e. acetylcholinesterase proteins was selected for the molecular docking study.

RESULTS

The structures of various alkaloids were drawn using Chem Draw Software, PDB was retrieved from the RCSB PDB database, and molecular docking study was performed on Molergo Virtual Docker. The potential alkaloids were identified with anti-Alzheimer potency.

CONCLUSION

Reserpine, vinblastine, ergotamine, and tubocurarine were found to exhibit potential anti-Alzheimer potency.

Association of CSF biomarkers with MRI brain changes in Alzheimer's disease

The relation between cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) and magnetic resonance imaging (MRI) measures is poorly understood in cognitively healthy individuals from the general population. Participants' (n = 226) mean age was 70.9 years (SD = 0.4). CSF concentrations of amyloid beta (Aβ)1-42, total tau (t-tau), phosphorylated tau (p-tau), neurogranin, and neurofilament light, and volumes of hippocampus, amygdala, total basal forebrain (TBF), and cortical thickness were measured. Linear associations between CSF biomarkers and MRI measures were investigated. In Aβ1-42 positives, higher t-tau and p-tau were associated with smaller hippocampus (P = 0.001 and P = 0.003) and amygdala (P = 0.005 and P = 0.01). In Aβ1-42 negatives, higher t-tau, p-tau, and neurogranin were associated with larger TBF volume (P = 0.001, P = 0.001, and P = 0.01). No associations were observed between the CSF biomarkers and an AD signature score of cortical thickness. AD-specific biomarkers in cognitively healthy 70-year-olds may be related to TBF, hippocampus, and amygdala. Lack of association with cortical thickness might be due to early stage of disease.

A Study of Assisted Screening for Alzheimer's Disease Based on Handwriting and Gait Analysis

Background

Alzheimer's disease (AD) is a progressive neurodegenerative disease that is not easily detected in the early stage. Handwriting and walking have been shown to be potential indicators of cognitive decline and are often affected by AD.

Objective

This study proposes an assisted screening framework for AD based on multimodal analysis of handwriting and gait and explores whether using a combination of multiple modalities can improve the accuracy of single modality classification.

Methods

We recruited 90 participants (38 AD patients and 52 healthy controls). The handwriting data was collected under four handwriting tasks using dot-matrix digital pens, and the gait data was collected using an electronic trail. The two kinds of features were fused as inputs for several different machine learning models (Logistic Regression, SVM, XGBoost, Adaboost, LightGBM), and the model performance was compared.

Results

The accuracy of each model ranged from 71.95% to 96.17%. Among them, the model constructed by LightGBM had the best performance, with an accuracy of 96.17%, sensitivity of 95.32%, specificity of 96.78%, PPV of 95.94%, NPV of 96.74%, and AUC of 0.991. However, the highest accuracy of a single modality was 93.53%, which was achieved by XGBoost in gait features.

Conclusions

The research results show that the combination of handwriting features and gait features can achieve better classification results than a single modality. In addition, the assisted screening model proposed in this study can achieve effective classification of AD, which has development and application prospects.

Periphery Biomarkers Predicting Conversion of Type 2 Diabetes to Pre-Alzheimer-Like Cognitive Decline: A Multicenter Follow-Up Study

Background

The prevalence of Alzheimer's disease (AD) is increasing, therefore, identifying biomarkers to predict those vulnerable to AD is imperative. Type 2 diabetes (T2D) serves as an independent risk factor for AD. Early prediction of T2D patients who may be more susceptible to AD, so as to achieve early intervention, is of great significance to reduce the prevalence of AD.

Objective

To establish periphery biomarkers that could predict conversion of T2D into pre-AD-like cognitive decline.

Methods

A follow-up study was carried out from 159 T2D patients at baseline. The correlations of cognitive states (by MMSE score) with multi-periphery biomarkers, including APOE genotype, plasma amyloid-β level, platelet GSK-3β activity, and olfactory score were analyzed by logistic regression. ROC curve was used for establishing the prediction model. Additionally, MRI acquired from 38 T2D patients for analyzing the correlation among cognitive function, biomarkers and brain structure.

Results

Compared with the patients who maintained normal cognitive functions during the follow-up period, the patients who developed MCI showed worse olfactory function, higher platelet GSK-3β activity, and higher plasma Aβ42/Aβ40 ratio. We conducted a predictive model which T2D patients had more chance of suffering from pre-AD-like cognitive decline. The MRI data revealed MMSE scores were positively correlated with brain structures. However, platelet GSK-3β activity was negatively correlated with brain structures.

Conclusions

Elevated platelet GSK-3β activity and plasma Aβ42/Aβ40 ratio with reduced olfactory function are correlated with pre-AD-like cognitive decline in T2D patients, which used for predicting which T2D patients will convert into pre-AD-like cognitive decline in very early stage.

Assessing causal associations between neurodegenerative diseases and neurological tumors with biological aging: a bidirectional Mendelian randomization study

Background

Aging is a significant risk factor for many neurodegenerative diseases and neurological tumors. Previous studies indicate that the frailty index, facial aging, telomere length (TL), and epigenetic aging clock acceleration are commonly used biological aging proxy indicators. This study aims to comprehensively explore potential relationships between biological aging and neurodegenerative diseases and neurological tumors by integrating various biological aging proxy indicators, employing Mendelian randomization (MR) analysis.

Methods

Two-sample bidirectional MR analyses were conducted using genome-wide association study (GWAS) data. Summary statistics for various neurodegenerative diseases and neurological tumors, along with biological aging proxy indicators, were obtained from extensive meta-analyses of GWAS. Genetic single-nucleotide polymorphisms (SNPs) associated with the exposures were used as instrumental variables, assessing causal relationships between three neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis), two benign neurological tumors (vestibular schwannoma and meningioma), one malignant neurological tumor (glioma), and four biological aging indicators (frailty index, facial aging, TL, and epigenetic aging clock acceleration). Sensitivity analyses were also performed.

Results

Our analysis revealed that genetically predicted longer TL reduces the risk of Alzheimer's disease but increases the risk of vestibular schwannoma and glioma (All Glioma, GBM, non-GBM). In addition, there is a suggestive causal relationship between some diseases (PD and GBM) and DNA methylation GrimAge acceleration. Causal relationships between biological aging proxy indicators and other neurodegenerative diseases and neurological tumors were not observed.

Conclusion

Building upon prior investigations into the causal relationships between telomeres and neurodegenerative diseases and neurological tumors, our study validates these findings using larger GWAS data and demonstrates, for the first time, that Parkinson's disease and GBM may promote epigenetic age acceleration. Our research provides new insights and evidence into the causal relationships between biological aging and the risk of neurodegenerative diseases and neurological tumors.

Diagnosis of behavioral symptoms as a predictor of institutionalization among Medicaid patients with dementia

OBJECTIVES

Behavioral symptoms are commonly observed in the course of dementia. This study aimed to assess the association of the diagnosis of a cluster of behavioral symptoms (e.g., agitation, aggression, psychotic symptoms, and delirium/wandering) with the likelihood of subsequent institutionalization.

METHODS

A retrospective cohort study of adults aged 65 and above diagnosed with dementia identified in the IBM® MarketScan® Multistate Medicaid database between October 01, 2015, and September 30, 2019, was conducted. The index date was defined as the first diagnosis date of dementia. The presence or absence of behavioral symptoms was identified in the 6 months prior to the index date (baseline). Institutionalization was evaluated 12 months (follow-up) post the index date. The association between diagnosed behavioral symptoms during the baseline period and institutionalization in the follow-up period was assessed using a multivariable logistic regression, adjusting for baseline sociodemographic and clinical characteristics.

RESULTS

The study cohort included 40,714 patients with dementia. A diagnosis of behavioral symptoms was found among 2,067 (5.1%) patients during the baseline period. An increased likelihood of institutionalization was found during the follow-up among patients with agitation and aggression in baseline (OR = 1.51 (95% CI: 1.18-1.92)) compared to patients without these symptoms at baseline. Patients with psychotic symptoms in baseline had significantly higher odds of getting institutionalized during the follow-up compared to patients without psychotic symptoms in baseline (OR = 1.36 (95% CI: 1.20-1.54)). Similarly, patients with symptoms of delirium and wandering in baseline had a higher likelihood of institutionalization than patients without these symptoms at baseline (OR = 1.61 (95% CI: 1.30-1.99)).

CONCLUSION

Several diagnosed behavioral symptoms were associated with a higher risk of institutionalization among older adults with dementia and should be considered when planning treatment strategies for the effective management of the condition.

How intention to join an Alzheimer's participant recruitment registry differs by race, ethnicity, sex, and family history: Results from a national survey of US adults

INTRODUCTION

Alzheimer's-focused participant recruitment registries are tools for accelerating enrollment into studies, however, registry members are primarily White women.

METHODS

We conducted a national online survey of 1501 adults ages 50-80, oversampling for Black and Hispanic/Latino respondents, assessing intention to join a generic "brain health" registry and to join a registry that required specific tasks.

RESULTS

Intention to join a registry was low (M 3.48, SD 1.77), and lower than intention to join a registry requiring specific tasks. Intention was greatest for registries requiring completing surveys (M 4.70, SD 1.77). Differences in intention were primarily between White women and Black women; differences between other groups were limited to specific tasks required.

DISCUSSION

The results indicate uncertainty about what a registry is, its purpose, and/or the concept of "brain health." Using the Reasoned Action Approach (RAA) to develop evidence-based outreach messages describing a registry and required tasks may increase diversity.

Idiopathic normal pressure hydrocephalus possibly affects the occurrence of proximal femoral fracture

AIMS

The clinical triad of idiopathic normal pressure hydrocephalus (iNPH) includes gait disturbance, dementia, and urinary incontinence. These symptoms are also frequently observed in patients with proximal femoral fracture (PFF). The aim of this study was to investigate the relationship between PFF and iNPH retrospectively.

PATIENTS AND METHODS

Of the130 patients over 80-years-old with PFF included in this study, 48 were assigned to the PFF group. Forty-eight patients with peripheral vertigo matched with the PFF group for age and sex were included in the control group. We compared the Evans' index (EI), which is a head computed tomography finding of iNPH, and the percentages of patients with EI>0.3 between the two groups. The PFF group was further divided into two subgroups depending on whether EI was higher or lower than 0.3 (the higher or lower subgroup, respectively). We compared the patient's gait abilities before PFF, causes of PFF, cognitive functions, and occurrence of urinary incontinence between both groups.

RESULTS

The mean value of EI in the PFF group was significantly higher than that in the control group (PFF group, 0.301; control group, 0.284; p=0.008). The percentages of patients with EI>0.3 in the PFF and control groups were 62.5% and 35.4%, respectively (p=0.014). In subgroup analyses, the gait ability before injury was worse in the higher subgroup than that in the lower subgroup and was prominent among individuals who could walk only with human assistance (p=0.018). There were no significant differences in other parameters.

CONCLUSION

Elderly patients with PFF may have underlying idiopathic normal pressure hydrocephalus.

LEVEL OF EVIDENCE

III; case-control comparative study.

Caenorhabditis elegans: A transgenic model for studying age-associated neurodegenerative diseases

Neurodegenerative diseases (NDs) are a heterogeneous group of aging-associated ailments characterized by interrupting cellular proteostasic machinery and the misfolding of distinct proteins to form toxic aggregates in neurons. Neurodegenerative diseases, which include Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), and others, are becoming an increasing threat to human health worldwide. The degeneration and death of certain specific groups of neurons are the hallmarks of these diseases. Over the past decades, Caenorhabditis eleganshas beenwidely used as a transgenic model to investigate biological processes related to health and disease. The nematode Caenorhabditis elegans (C. elegans) has developed as a powerful tool for studying disease mechanisms due to its ease of genetic handling and instant cultivation while providing a whole-animal system amendable to several molecular and biochemical techniques. In this review, we elucidate the potential of C. elegans as a versatile platform for systematic dissection of the molecular basis of human disease, focusing on neurodegenerative disorders, and may help better our understanding of the disease mechanisms and search for new therapeutics for these devastating diseases.

Decreased DHA-containing phospholipids in the neocortex of dementia with Lewy bodies are associated with soluble Aβ42 , phosphorylated α-synuclein, and synaptopathology

Docosahexaenoic acid (DHA) is an essential omega-3 polyunsaturated fatty acid implicated in cognitive functions by promoting synaptic protein expression. While alterations of specific DHA-containing phospholipids have been described in the neocortex of patients with Alzheimer's disease (AD), the status of these lipids in dementia with Lewy bodies (DLB), known to manifest aggregated α-synuclein-containing Lewy bodies together with variable amyloid pathology, is unclear. In this study, post-mortem samples from the parietal cortex of 25 DLB patients and 17 age-matched controls were processed for phospholipidomics analyses using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) platform. After controlling for false discovery rate, six out of the 46 identified putative DHA-phospholipid species were significantly decreased in DLB, with only one showing increase. Altered putative DHA-phospholipid species were subsequently validated with further LC-MS/MS measurements. Of the DHA-containing phospholipid (DCP) species showing decreases, five negatively correlated with soluble beta-amyloid (Aβ42) levels, whilst three also correlated with phosphorylated α-synuclein (all p < 0.05). Furthermore, five of these phospholipid species correlated with deficits of presynaptic Rab3A, postsynaptic neurogranin, or both (all p < 0.05). Finally, we found altered immunoreactivities of brain lysolipid DHA transporter, MFSD2A, and the fatty acid binding protein FABP5 in DLB parietal cortex. In summary, we report alterations of specific DCP species in DLB, as well as their associations with markers of neuropathological burden and synaptopathology. These results support the potential role of DHA perturbations in DLB as well as therapeutic targets.

Differences in Risk of Alzheimer's Disease Following Later-Life Traumatic Brain Injury in Veteran and Civilian Populations

OBJECTIVE

To directly compare the effect of incident age 68+ traumatic brain injury (TBI) on the risk of diagnosis of clinical Alzheimer's disease (AD) in the general population of older adults, and between male veterans and nonveterans; to assess how this effect changes with time since TBI.

SETTING AND PARTICIPANTS

Community-dwelling traditional Medicare beneficiaries 68 years or older from the Health and Retirement Study (HRS).

DESIGN

Fine-Gray models combined with inverse-probability weighting were used to identify associations between incident TBI, post-TBI duration, and TBI treatment intensity, with a diagnosis of clinical AD dementia. The study included 16 829 older adults followed over the 1991-2015 period. For analyses of veteran-specific risks, 4281 veteran males and 3093 nonveteran males were identified. Analysis of veteran females was unfeasible due to the age structure of the population. Information on occurrence(s) of TBI, and onset of AD and risk-related comorbidities was constructed from individual-level HRS-linked Medicare claim records while demographic and socioeconomic risk factors were based on the survey data.

RESULTS

Later-life TBI was strongly associated with increased clinical AD risk in the full sample (pseudo-hazard ratio [HR]: 3.22; 95% confidence interval [CI]: 2.57-4.05) and in veteran/nonveteran males (HR: 5.31; CI: 3.42-7.94), especially those requiring high-intensity/duration care (HR: 1.58; CI: 1.29-1.91). Effect magnitude decreased with time following TBI (HR: 0.72: CI: 0.68-0.80).

CONCLUSION

Later-life TBI was strongly associated with increased AD risk, especially in those requiring high-intensity/duration care. Effect magnitude decreased with time following TBI. Univariate analysis showed no differences in AD risk between veterans and nonveterans, while the protective effect associated with veteran status in Fine-Gray models was largely due to differences in demographics, socioeconomics, and morbidity. Future longitudinal studies incorporating diagnostic procedures and documentation quantifying lifetime TBI events are necessary to uncover pathophysiological mediating and/or moderating mechanisms between TBI and AD.

The Effects of Ninjinyoeito on Impaired Spatial Memory and Prefrontal Cortical Synaptic Plasticity through α-Amino-3-hydroxy-5-4-isoxazole Propionic Acid Receptor Subunit in a Rat Model with Cerebral Ischemia and β-Amyloid Injection

Ninjinyoeito (NYT), a traditional Japanese medicine, is effective for improving physical strength and treating fatigue and anorexia. Recently, a clinical report revealed that NYT ameliorates cognitive dysfunction in Alzheimer's disease (AD) patients, although the mechanisms remain unclear. AD is a neurodegenerative disorder accompanied by a progressive deficit in memory. Current therapeutic agents are largely ineffective in treating cognitive dysfunction in AD patients. In this study, we investigated the effects of NYT on spatial memory impairment in a rat model of dementia. Rats were prepared with transient cerebral ischemia and intraventricular injection of β-amyloid1-42 for 7 days (CI + Aβ). NYT was orally administered for 7 days after cerebral ischemia. We evaluated spatial memory using the Morris water maze and investigated the expression of α-amino-3-hydroxy-5-4-isoxazole propionic acid receptor subunits, the phosphorylation level of glutamate receptor A (GluA)1 at serine sites S831 and S845, and the Ca2+/calmodulin-dependent protein kinase II (CaMKII) in the hippocampus and prefrontal cortex of CI + Aβ rats. In the CI + Aβ rats, NYT treatment shortened the extended time to reach the platform. However, NYT did not restore the decrease in the hippocampal GluA1, GluA2, or CaMKII expression but increased prefrontal cortical phosphorylation levels of S845-GluA1 and CaMKII. Therefore, NYT may alleviate spatial memory impairment by promoting glutamatergic transmission involved in the phosphorylation of S845-GluA1 and CaMKII in the prefrontal cortex of CI + Aβ rats. Our results suggest that NYT is a valuable treatment for AD patients.

Transcriptomic Analysis in the Hippocampus and Retina of Tg2576 AD Mice Reveals Defective Mitochondrial Oxidative Phosphorylation and Recovery by Tau 12A12mAb Treatment

Increasing evidence implicates decreased energy metabolism and mitochondrial dysfunctions among the earliest pathogenic events of Alzheimer's disease (AD). However, the molecular mechanisms underlying bioenergetic dysfunctions in AD remain, to date, largely unknown. In this work, we analyzed transcriptomic changes occurring in the hippocampus and retina of a Tg2576 AD mouse model and wild-type controls, evaluating their functional implications by gene set enrichment analysis. The results revealed that oxidative phosphorylation and mitochondrial-related pathways are significantly down-regulated in both tissues of Tg2576 mice, supporting the role of these processes in the pathogenesis of AD. In addition, we also analyzed transcriptomic changes occurring in Tg2576 mice treated with the 12A12 monoclonal antibody that neutralizes an AD-relevant tau-derived neurotoxic peptide in vivo. Our analysis showed that the mitochondrial alterations observed in AD mice were significantly reverted by treatment with 12A12mAb, supporting bioenergetic pathways as key mediators of its in vivo neuroprotective and anti-amyloidogenic effects. This study provides, for the first time, a comprehensive characterization of molecular events underlying the disrupted mitochondrial bioenergetics in AD pathology, laying the foundation for the future development of diagnostic and therapeutic tools.

Is later-life depression a risk factor for Alzheimer's disease or a prodromal symptom: a study using post-mortem human brain tissue?

BACKGROUND

Depression and dementia are both common diseases. Although new cases of depression are more common in younger adults, there is a second peak at the age of 50 years suggesting a different pathological process. Late-life depression (LLD) is associated with dementia. However, it remains unclear whether depression represents a dementia prodrome or is a true risk factor for its development. LLD is thought to have a vascular component and this may be a possible link between depression and dementia. We hypothesised that later-life depression is a prodromal manifestation of dementia and would therefore be associated with more AD, and/or ischaemic brain abnormalities that are present in earlier-life depression or in age- and sex-matched controls.

METHODS

We assessed post-mortem orbitofrontal cortex and dorsolateral pre-frontal cortex from 145 individuals in 4 groups: 28 18-50-year-olds with depression, 30 older individuals (ages 51-90) with depression, 28 with early AD (Braak tangle stages III-IV) and 57 matched controls (17 early-life, 42 later-life). Levels of Aβ, phospho-tau and α-synuclein were assessed by immunohistochemistry and ELISA. To quantify chronic ischaemia, VEGF, MAG and PLP1 were measured by ELISA. To assess pericyte damage, PDGFRB was measured by ELISA. For blood-brain barrier leakiness, JAM-A, claudin 5 and fibrinogen were measured by ELISA. To quantity endothelial activation, the ratio of ICAM1:collagen IV was assessed by immunohistochemistry.

RESULTS

There was no evidence of chronic cerebral hypoperfusion or increased Aβ/tau in either depression group. There was also no indication of pericyte damage, increased blood-brain barrier leakiness or endothelial activation in the OFC or DLPFC in the depression groups.

CONCLUSIONS

Contrary to some previous findings, we have not found evidence of impaired vascular function or increased Aβ in LLD. Our study had a relatively small sample size and limitations in the availability of clinical data. These results suggest that depression is a risk factor for dementia rather than an early manifestation of AD or a consequence of cerebral vascular insufficiency.

Benzimidazole-Based Schiff Base Hybrid Scaffolds: A Promising Approach to Develop Multi-Target Drugs for Alzheimer's Disease

A series of benzimidazole-based Schiff base derivatives (1-18) were synthesized and structurally elucidated through 1H NMR, 13C NMR and HREI-MS analysis. Subsequently, these synthetic derivatives were subjected to evaluation for their inhibitory capabilities against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). All these derivatives showed significant inhibition against AChE with an IC50 value in the range of 123.9 ± 10.20 to 342.60 ± 10.60 µM and BuChE in the range of 131.30 ± 9.70 to 375.80 ± 12.80 µM in comparison with standard Donepezil, which has IC50 values of 243.76 ± 5.70 µM (AChE) and 276.60 ± 6.50 µM (BuChE), respectively. Compounds 3, 5 and 9 exhibited potent inhibition against both AChE and BuChE. Molecular docking studies were used to validate and establish the structure-activity relationship of the synthesized derivatives.

The efficacy and practicality of the Neurotrack Cognitive Battery assessment for utilization in clinical settings for the identification of cognitive decline in an older Japanese population

Introduction

Japan has the largest aging population with 33% of the population over the age of 60 years. The number of Japanese adults with dementia is estimated to be approximately 4.6 million, comprising nearly 15% of the older adult population. It is critical to administer cognitive assessments early in the disease state that have high reliability and low user burden to detect negative cognitive changes as early as possible; however, current preclinical AD detection methods are invasive, time-consuming, and expensive. A number of traditional and digital cognitive assessments are also available, but many of these tests are time-consuming, taxing to the user, and not widely scalable. The purpose of this study was to incorporate a digital cognitive assessment battery into a standard clinical assessment performed within a Japanese-based neuropsychology clinic to assess the diagnostic accuracy and the relationship between the digital Neurotrack Cognitive Assessment Battery (N-CAB) to traditional cognitive assessments.

Methods

Healthy individuals and probable Alzheimer's patients completed the N-CAB, as well as two traditional cognitive assessments, the Mini Mental Status Exam (MMSE) and the Revised Hasegawa's Dementia Scale (HDS-R).

Results

Our results demonstrate the Image Pairs hand-response phase of the N-CAB had the highest diagnostic accuracy with 95% sensitivity and 89% specificity to probable Alzheimer's disease. This was closely followed by the Symbol Match assessment, with a 96% sensitivity and 74% specificity to probable Alzheimer's disease. Additionally, Symbol Match and Path Points used in combination resulted in a sensitivity of 94%, specificity of 90%; a model with all N-CAB assessments resulted in a sensitivity and specificity of 100%. All N-CAB assessments had moderate to strong and significant correlations with the MMSE and HDS-R.

Discussion

Together, this suggests that the N-CAB assessment battery may be an appropriate alternative for the clinical screening of cognition for earlier detection of Alzheimer's disease.

Early classification of Alzheimer's disease phenotype based on hippocampal electrophysiology in the TgF344-AD rat model

The hippocampus plays a vital role in navigation, learning, and memory, and is affected in Alzheimer's disease (AD). This study investigated the classification of AD-transgenic rats versus wild-type littermates using electrophysiological activity recorded from the hippocampus at an early, presymptomatic stage of the disease (6 months old) in the TgF344-AD rat model. The recorded signals were filtered into low frequency (LFP) and high frequency (spiking activity) signals, and machine learning classifiers were employed to identify the rat genotype (TG vs. WT). By analyzing specific frequency bands in the low frequency signals and calculating distance metrics between spike trains in the high frequency signals, accurate classification was achieved. Gamma band power emerged as a valuable signal for classification, and combining information from both low and high frequency signals improved the accuracy further. These findings provide valuable insights into the early stage effects of AD on different regions of the hippocampus.

The Role of Protein-L-isoaspartyl Methyltransferase (PIMT) in the Suppression of Toxicity of the Oligomeric Form of Aβ42, in Addition to the Inhibition of Its Fibrillization

The oligomeric form of amyloid-β peptide (Aβ42) plays a crucial role in the pathogenesis of Alzheimer's disease (AD) and is responsible for cognitive deficits. The soluble oligomers are believed to be more toxic compared to the fibril form. Protein-L-isoaspartyl methyltransferase (PIMT) is a repair enzyme that converts aberrant isoAsp residues, formed spontaneously on isomerization of normal Asp and Asn residues, back to typical Asp. It was shown to inhibit the fibrillization of Aβ42 (containing three Asp residues), and here, we investigate its effect on the size, conformation, and toxicity of Aβ42 oligomers (AβO). Far-UV CD indicated a shift in the conformational feature of AβOs from the random coil to β-sheet in the presence of PIMT. Binding of bis-ANS to different AβOs (obtained using different concentrations of Aβ42 monomer) indicated the correlation of size of oligomers to hydrophobicity: the smallest AβO having the highest hydrophobicity is the most toxic. Dynamic light scattering showed an increase in size of AβO with the addition of PIMT, a contrasting role to that on Aβ fibril. Assays using PC12-derived neurons showed the neuroprotective role of PIMT against AβO-induced toxicity. Furthermore, we have elaborated on the molecular mechanism of the antifibrillar action of PIMT and how this function is correlated with its enzymatic activity. PIMT has a more pronounced effect on AβO as compared to a small heat shock protein, pointing to its importance for the amelioration of the adverse effect of both Aβ42 oligomers and fibrils.

Exercise therapy to prevent and treat Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease in the elderly with dementia, memory loss, and severe cognitive impairment that imposes high medical costs on individuals. The causes of AD include increased deposition of amyloid beta (Aβ) and phosphorylated tau, age, mitochondrial defects, increased neuroinflammation, decreased synaptic connections, and decreased nerve growth factors (NGF). While in animals moderate-intensity exercise restores hippocampal and amygdala memory through increased levels of p-AKT, p-TrkB, and p-PKC and decreased levels of Aβ, tau phosphorylation, and amyloid precursor proteins (APP) in AD. Aerobic exercise (with an intensity of 50-75% of VO2 max) prevents hippocampal volume reduction, spatial memory reduction, and learning reduction through increasing synaptic flexibility. Exercise training induces the binding of brain-derived neurotrophic factor (BDNF) to TrkB and the binding of NGF to TrkA to induce cell survival and neuronal plasticity. After aerobic training and high-intensity interval training, the increase of VEGF, angiopoietin 1 and 2, NO, tPA, and HCAR1 in cerebral vessels causes increased blood flow and angiogenesis in the cerebellum, motor cortex, striatum, and hippocampus. In the hippocampus, exercise training decreases mitochondrial fragmentation, DRP1, and FIS1, improving OPA1, MFN1, MFN2, and mitochondrial morphology. In humans, acute exercise as an anti-inflammatory condition causes an acute increase in IL-6 and an increase in anti-inflammatory factors such as IL-1RA and IL-10. Moderate-intensity exercise also inhibits inflammatory markers such as IFN-γ, IL-1β, IL-6, CRP, TNF-α, sTNFR1, COX-2, and NF-κB. Aerobic exercise significantly increases plasma levels of BDNF, nerve growth factor, synaptic plasticity, motor activity, spatial memory, and exploratory behavior in AD subjects. Irisin is a myokine released from skeletal muscle during exercise and protects the hippocampus by suppressing Aβ accumulation and promoting hippocampal proliferation through STAT3 signaling. Therefore, combined exercise training such as aerobic training, strength training, balance and coordination training, and cognitive and social activities seems to provide important benefits for people with AD.

Management Practice and Clinical Outcomes of Dementia in Sub-Saharan Africa: A Systematic Review

Background

Dementia is a severe neurodegenerative disorder and it is a group of acquired symptoms associated with impaired cognitive functions. In low-income settings particularly in Sub-Saharan Africa (SSA), it is often seen as part of normal aging. Environmental, behavioral, and lifestyle interventions have the potential to alter the disease course of dementia.

Objective

This study is aimed to synthesize the literature/evidence(s) on the management practice and treatment outcomes of dementia in SSA.

Method

Comprehensive literature was searched in PubMed database, Cochrane Library, and Google Scholar. Eligibility has been set, and based on the criteria, initially, a total of 442 results were obtained, and from those around 183 articles were duplicated. After examining titles and abstracts of records 26 articles were identified. Finally, five randomized clinical trials (RCT) and three prospective cohort studies that were reported on the management practice and treatment outcome of dementia in SSA were eligible for analysis. RCT and prospective cohort studies were used to strengthen the quality of evidence. The quality of the included RCT studies was assessed by using the Cochrane Risk of Bias Tool.

Result

A total of 2781 patient data were included in the final analysis. Of these, 2354 patients were obtained from 5 RCTs and 427 patients from 3 prospective cohort studies, which were conducted in SSA countries. RCT studies were done on the feasibility and clinical effectiveness of cognitive stimulation therapy (CST) showed improvements in language memory domains and physical health. In addition, studies that focus on the management of human immunodeficiency virus-associated dementia (HIVAD) were reported to improve neurocognitively.

Conclusion

CST is applicable in low-resource settings and it shows improvements in cognitive function and quality of life. Early initiation of combination antiretroviral therapy in resource-limited settings has been associated with improvement in the cognitive function of HIVAD.