Dementia and Geriatric Cognitive Disorders最新文献

Introduction: Carnosine can suppress secondary complications in diabetes and show robust neuroprotective activity against neurodegenerative diseases. Here, we report that carnosine ameliorates diabetes-associated cognitive decline in vivo through the modulation of autophagy.

Methods: A high-fat diet (HFD) and one intraperitoneal injection of 30 mg/kg streptozotocin (STZ) were used to induce type 2 diabetes mellitus in Sprague-Dawley rats. The rats were randomly divided into five groups: control (CON), HFD/STZ, and three intragastric carnosine treatment groups receiving low (100 mg/kg), medium (300 mg/kg), and high (900 mg/kg) doses over 12 weeks. Body weight, blood glucose levels, and cognitive function were continuously monitored. From excised rat hippocampi, we determined superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels; carnosine concentration; protein expressions of Akt, mTOR and the autophagy markers LC3B and P62 and performed histopathological evaluations of the cornu ammonis 1 region.

Results: The HFD/STZ group showed increased blood glucose levels and decreased body weight compared to the CON group. However, there were no significant differences in body weight and blood glucose levels between carnosine-treated and -untreated HFD-STZ-induced diabetic rats. Diabetic animals showed obvious learning and memory impairments in the Morris water maze test compared to the CON group. Compared to those in the HFD/STZ group, carnosine increased SOD activity and decreased MDA levels, increased hippocampal carnosine concentration, increased p-Akt and p-mTOR expression, decreased LC3B and P62 expression, alleviated neuronal injuries, and improved cognitive performance in a dose-dependent manner.

Conclusion: Independent of any hyperglycemic effect, carnosine may improve mild cognitive impairments by mitigating oxidative stress, activating the Akt/mTOR pathway, and modulating autophagy in the hippocampus of type 2 diabetic rats.

Introduction: Transcranial Doppler (TCD) sonography is a noninvasive tool for measuring cerebrovascular hemodynamics. Studies have reported alterations in cerebrovascular hemodynamics in normal aging, mild cognitive impairment (MCI), and dementia, as well as in different etiologies of dementia. This systematic review and meta-analysis was designed to investigate the relationship between cerebral blood velocity (CBv) and pulsatility index (PI) in the middle cerebral artery (MCA) in persons with MCI and dementia.

Methods: A systematic literature search was conducted in Pubmed, Embase, Cochrane Library, Epistemonikos, PsychINFO, and CINAHL. The search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. After screening of 33,439 articles, 86 were reviewed in full-text, and 35 fulfilled the inclusion criteria.

Results: CBv was significantly lower and PI significantly higher in MCA in vascular dementia (VaD) and Alzheimer's disease (AD) compared to cognitively normal (CN) older persons. Also, CBv was lower in MCI compared to CN. There were no significant differences in CBv in MCA in AD compared with VaD, although PI was higher in VaD compared to AD.

Conclusion: Alterations in cerebrovascular hemodynamics are seen in AD, VaD, and MCI. While PI was slightly higher in VaD compared to AD, the reduction in CBv appears to be equally pronounced across neurodegenerative and vascular etiologies of dementia.

Introduction: Depression is often difficult to detect in long-term care (LTC) patients with major neurocognitive disorders (MNCD), and an observer-rated screening scale could facilitate assessments. This study aimed to establish the external validity and reliability of the Nursing Homes Short Depression Inventory (NH-SDI) in LTC patients with MNCD and to compare its estimates to the Cornell Scale for Depression in Dementia (CSDD), the most used scale for depression in MNCD.

Methods: A focus discussion group of experts assessed the content validity of the NH-SDI. Then, a convenience sample of 93 LTC patients with MNCD was observer-rated by trained nurses with the NH-SDI and CSDD. For 57 patients, a medical assessment of depression was obtained, and screening accuracy estimates were generated.

Results: The prevalence of depression was 8.8% as per reference standard. NH-SDI's content validity was judged acceptable with minor item wording modifications and specifications. The NH-SDI (cut-off ≥3) achieved 100% (95% confidence interval [CI]: 46-100%) sensitivity, 83% (95% CI: 69-91%) specificity, and 36% (95% CI: 14-64%) positive predictive value (PPV). The CSDD (cut-off ≥3) achieved 100% (95% CI: 46-100%) sensitivity, 75% (95% CI: 61-86%) specificity, and 28% (95% CI: 11-54%) PPV. No significant differences in areas under the receiver operating characteristic curve were found between scales. The NH-SDI and CSDD were highly correlated (rs = 0.913; p < 0.001) and reliable (ICC = 0.77; p < 0.001).

Conclusion: The NH-SDI appears valid and reliable in LTC patients with MNCD and quicker than the CSDD to rule out depression in a busy or short-staffed setting.

Introduction: Stem cell-based regenerative medicine has provided an excellent opportunity to investigate therapeutic strategies and innovative treatments for Alzheimer's disease (AD). However, there is an absence of visual overviews to assess the published literature systematically.

Methods: In this review, the bibliometric approach was used to estimate the searched data on stem cell research in AD from 2004 to 2022, and we also utilized CiteSpace and VOSviewer software to evaluate the contributions and co-occurrence relationships of different countries/regions, institutes, journals, and authors as well as to discover research hot spots and encouraging future trends in this field.

Results: From 2004 to 2022, a total of 3,428 publications were retrieved. The number of publications and citations on stem cell research in AD has increased dramatically in the last nearly 20 years, especially since 2016. North America and Asia were the top 2 highest output regions. The leading country in terms of publications and access to collaborative networks was the USA. Centrality analysis revealed that the UCL (0.05) was at the core of the network. The Journal of Alzheimer's Disease (n = 102, 2.98%) was the most productive academic journal. The analyses of keyword burst detection indicated that exosomes, risk factors, and drug delivery only had burst recently. Citations and co-citation achievements clarified that cluster #0 induced pluripotent stem cells, #2 mesenchymal stem cells, #3 microglia, and #6 adult hippocampal neurogenesis persisted to recent time.

Conclusion: This bibliometric analysis provides a comprehensive guide for clinicians and scholars working in this field. These analysis and results hope to provide useful information and references for future understanding of the challenges behind translating underlying stem cell biology into novel clinical therapeutic potential in AD.

Introduction: Hearing loss (HL) is considered a potentially modifiable risk factor for dementia. We aimed to examine the relationship between HL and incident dementia diagnosis in a province-wide population-based cohort study with matched controls.

Methods: Administrative healthcare databases were linked to generate a cohort of patients who were aged ≥40 years at their first claimed hearing amplification devices (HAD) between April 2007 and March 2016 through the Assistive Devices Program (ADP) (257,285 with claims and 1,005,010 controls). The main outcome was incident dementia diagnosis, ascertained using validated algorithms. Dementia incidence was compared between cases and controls using Cox regression. Patient, disease, and other risk factors were examined.

Results: Dementia incidence rates (per 1,000 person-years) were 19.51 (95% confidence interval [CI]: 19.26-19.77) and 14.15 (95% CI: 14.04-14.26) for the ADP claimants and matched controls, respectively. In adjusted analyses, risk of dementia was higher in ADP claimants compared with controls (hazard ratio [HR]: 1.10 [95% CI: 1.09-1.12, p < 0.001]). Subgroup analyses showed a dose-response gradient, with risk of dementia higher among patients with bilateral HADs (HR: 1.12 [95% CI: 1.10-1.14, p < 0.001]), and an exposure-response gradient, with increasing risk over time from April 2007-March 2010 (HR: 1.03 [95% CI: 1.01-1.06, p = 0.014]), April 2010-March 2013 (HR: 1.12 [95% CI: 1.09-1.15, p < 0.001]), and April 2013-March 2016 (HR: 1.19 [95% CI: 1.16-1.23, p < 0.001]).

Conclusion: In this population-based study, adults with HL had an increased risk of being diagnosed with dementia. Given the implications of HL on dementia risk, understanding the effect of hearing interventions merits further investigation.

Introduction: This paper provides a summary of findings on the public's knowledge and attitudes towards dementia. We aim to investigate if the attitudes of Singaporeans towards dementia have changed over the years by adopting a questionnaire used in a similar study in 2012.

Methods: A cross-sectional, descriptive study was conducted through the dissemination of an existing, online questionnaire to participants above 16 years of age. Out of 1,500 subjects, results from 1,373 participants were analysed. Descriptive statistics were used to analyse and compare results from the 2012 study while a latent class analysis was performed to understand the categories of study participants based on varying levels of attitudes, knowledge and stigma.

Results: The mean age of study participants was 43.8 (SD = 15.7). Majority of the participants were females (76.5%), between 51 and 60 years of age (29.6%) and belonged to the Chinese ethnic group (77.8%). Results demonstrated that there were significant differences in attitudes towards dementia between 2012 and 2021. There was a 70.2% improvement in stigma-associated attitudes and an increase in correct responses to 4 out of 5 questions in the knowledge section.

Conclusion: Findings of this study suggest that the general public has a better knowledge and more positive attitude towards dementia. This could have been attributed to higher literacy levels of the current study population and effectiveness of established outreach initiatives in Singapore. However, further research with a more balanced representation of ethnic and cultural groups would offer more comprehensive insights into dementia health literacy.

Introduction: The study aimed to explore longitudinal cognitive outcomes and to ascertain predictors of conversion to dementia in a hospital-based mild cognitive impairment (MCI) cohort classified according to the neuropsychological phenotype at baseline.

Materials and methods: Subjects aged >55 years who had a clinical diagnosis of MCI at initial visit between 2010 and 2018, with at least one formal neuropsychological assessment at baseline and follow-up of a minimum of 2 years were included. The prospective study was completed based on evaluation at last follow-up to gauge conversion to dementia, quantification of performance on activities of daily living and when available, longitudinal neuropsychological test scores.

Results: Ninety-five patients with MCI met the inclusion criteria with a mean age of 68.4 ± 6.4 years at baseline and a mean duration of follow-up for 6.4 ± 3.2 years. The cumulative conversion rate to dementia was 22.2% (21/95) and the annualized conversion rate was 3.3% per year of follow-up. The majority of subjects who had converted had multidomain MCI (66%). Only white matter changes on MRI brain revealed correlation with baseline neuropsychology tests. The multivariate logistic regression analysis revealed the utility of lower baseline list recognition (adjusted odds ratio: 0.735 [95% confidence interval: 0.589-0.916]; p 0.006), lower immediate logical memory (0.885 [0.790-0.990]; p 0.03), and high perseverative error scores on set shifting (3.116 [1.425-6.817]; p 0.004) as predictors of conversion. A model score of +2.615 could predict conversion with sensitivity of 72% and specificity of 98% over 6.4 years follow-up.

Conclusion: There was a higher risk of conversion associated with multidomain MCI. Logistic regression-based estimations of dementia risk utilizing domain-based neuropsychology test scores in MCI have high specificity for diagnosis at baseline.