Effect of probiotics on cognitive function in adults with mild cognitive impairment or Alzheimer's disease: A meta-analysis of randomized controlled trials

BACKGROUND

Recent clinical studies have yielded controversial results regarding the effect of probiotics on cognitive function in Alzheimer's disease (AD) or mild cognitive impairment (MCI) subjects. To clarify the efficacy of probiotics on cognition, we conducted a meta-analysis of randomized controlled trials (RCTs).

METHODS

Instructions of the PRISMA 2020 statement were followed. Literature from the PubMed, Embase and Cochrane databases were systematically searched and manually screened for relevant published RCTs. We performed statistical analysis using RevMan, and assessed the risk of bias using the R software.

RESULTS

A total of 12 studies comprising 852 patients with MCI or AD were identified. The results of meta-analysis showed that probiotics improved global cognitive function (SMD=0.67; 95% CI, 0.32, 1.02), recall/delayed memory (SMD=0.67; 95% CI: 0.32, 1.02), attention (SMD=0.31; 95% CI: 0.04, 0.58) and visuospatial/constructional (SMD=0.24; 95% CI: 0.06, 0.42) cognitive domain.

CONCLUSION

This meta-analysis found that probiotic supplementation is associated with an improvement in cognitive performance among patients with AD and MCI. However, current evidence is limited, and more reliable large-scale RCTs with higher methodological quality are needed.

The association between periodontitis and cerebrovascular disease, and dementia. Scientific report of the working group of the Spanish Society of Periodontology and the Spanish Society of Neurology

OBJECTIVE

This article reviews the scientific evidence on the relationship between periodontitis and neurological disease, and particularly cerebrovascular disease and dementia. We also issue a series of recommendations regarding the prevention and management of periodontitis and these neurological diseases at dental clinics and neurology units.

DEVELOPMENT

In response to a series of questions proposed by the SEPA-SEN working group, a literature search was performed, with no restrictions on study design, to identify the most relevant articles on the association between periodontitis and cerebrovascular disease and dementia from the perspectives of epidemiology, treatment, and the biological mechanisms involved in these associations.

CONCLUSIONS

Periodontitis increases the risk of ischaemic stroke and Alzheimer dementia. Recurrent bacterial infections and increased low-grade systemic inflammation seem to be possible biological mechanisms underlying this association. Limited evidence suggests that various oral health interventions can reduce the future risk of cerebrovascular disease and dementia.

Performance on the Latin American version of the Face-Name Associative Memory Exam (LAS-FNAME) distinguishes individuals with Mild Cognitive Impairment from age-matched controls in a sample from Argentina

INTRODUCTION

The Latin American Spanish version of the Face-Name Associative Memory Exam (LAS-FNAME) has shown promise in identifying cognitive changes in those at risk for Alzheimer's disease (AD). However, its applicability for Mild Cognitive Impairment (MCI) detection in the Latin American population remains unexplored. This study aims to analyze the psychometric properties in terms of validity and reliability and diagnostic performance of the LAS-FNAME for the detection of memory disorders in patients with amnestic MCI (aMCI).

MATERIALS AND METHODS

The study included 31 participants with aMCI, diagnosed by a neurologist according to Petersen's criteria, and 19 healthy controls. Inclusion criteria for the aMCI group were to be 60 years of age or older, report cognitive complaints, have a memory test score (Craft Story 21) below a -1.5 z-score and have preserved functioning in activities of daily living. Participants completed LAS-FNAME and a comprehensive neuropsychological assessment.

RESULTS

LAS-FNAME showed the ability to discriminate against healthy controls from patients with aMCI (AUC= 75) in comparison with a gold-standard memory test (AUC = 69.1). LAS-FNAME also showed evidence of concurrent and divergent validity with a standard memory test (RAVLT) (r = 0.58, p < .001) and with an attention task (Digit Span) (r = -0.37, p = .06). Finally, the reliability index was very high (α = 0.88).

DISCUSSION

LAS-FNAME effectively distinguished aMCI patients from healthy controls, suggesting its potential for detecting early cognitive changes in Alzheimer's prodromal stages among Spanish speakers.

The potential diagnostic accuracy of circulating microRNAs for Alzheimer's disease: A meta-analysis

BACKGROUND & OBJECTIVE

Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative disease that seriously affects cognitive ability and has become a key public health problem. Many studies have identified the possibility of peripheral blood microRNA as effective non-invasive biomarkers for AD diagnosis, but the results are inconsistent. Therefore, we carried out this meta-analysis to evaluate the diagnostic accuracy of circulating microRNAs in the diagnosis of AD patients.

METHODS

We performed a systematic literature search of the following databases: PubMed, EMBASE, Web of Science, Cochrane Library, Wanfang database and China National Knowledge Infrastructure, updated to March 15, 2021. A random effects model was used to pool the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and area under the curve. Meta-regression and subgroup analysis were performed to explore the sources of heterogeneity, and Deeks' funnel plot was used to assess whether there was publication bias.

RESULTS

62 studies from 18 articles were included in this meta-analysis. The pooled sensitivity was 0.82 (95% CI: 0.78-0.85), specificity was 0.80 (95% CI: 0.76-0.83), PLR was 4. 1 (95% CI: 3.4-4.9), NLR was 0.23 (95% CI: 0.19-0.28), DOR was 18 (95% CI: 13-25) and AUC was 0.88 (95% CI: 0.84-0.90). Subgroup analysis shows that the microRNA clusters of plasma type performed a better diagnostic accuracy of AD patients. In addition, publication bias was not found.

CONCLUSIONS

Circulating microRNAs can be used as a promising non-invasive biomarker in AD diagnosis.

[Neuropsychological differences in Alzheimer's disease depending on the age of onset]

INTRODUCTION

Early-onset Alzheimer's disease (EOAD) has been defined as a dementia due to AD presenting before the arbitrarily established age of 65 (as opposed to late-onset Alzheimer's disease or LOAD). There is still little research about other age sub-groups, the use of so-called senile dementia has been banished, usually including it within the late-onset Alzheimer's dementia. To the extent of our knowledge, there are no studies comparing the neuropsychological features of very-late-onset patients with early and late-onset ones.

METHODS

We retrospectively selected 359 patients with a diagnosis of probable AD dementia. We subdivided patients into three groups attending to the age of onset of the disease: early-onset AD (EOAD; younger than 65 years old), late-onset AD (LOAD; between 65 and 80) and very-late-onset AD (VLOAD; defined here as onset age older than 80), and then we compared their neuropsychological results.

RESULTS

AD patients with a younger age at onset scored worse on attention, executive function and visuospatial skills, while older-onset patients scored worse in memory tasks and language. Patients with a very-late-onset differed from the late-onset ones in a greater impairment of semantic fluency and naming.

CONCLUSION

Although the point of separation between EOAD and later-onset forms of EA at the age of 65 is an arbitrary one, our study shows that there are significant differences between these groups from a neuropsychological point of view. However, these differences do seem to follow a linear trend with age, rather than representing fundamentally distinct clinical pictures.

Association between psoriasis and dementia: A systematic review

INTRODUCTION

Risk factors for dementia include genetic factors, aging, environmental factors, certain diseases, and unhealthy lifestyle; most types of dementia share a common chronic systemic inflammatory phenotype. Psoriasis is also considered to be a chronic systemic inflammatory disease. It has been suggested that psoriasis may also contribute to the risk of dementia. The aim of this study was to systematically review the literature on the association between psoriasis and dementia.

DEVELOPMENT

Articles were selected according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched the PubMed and Web of Science databases to identify articles published in peer-reviewed journals and studying the association between psoriasis and dementia. Studies meeting the inclusion criteria were reviewed. We used the Newcastle-Ottawa Scale to assess the quality of each study. After applying the inclusion and exclusion criteria, we included 8 studies for review, 3 of which were found to present a higher risk of bias. Six of the 8 studies supported the hypothesis that prior diagnosis of psoriasis increases the risk of dementia; one study including only a few cases reported that psoriasis decreased the risk of dementia, and one study including relatively young patients found no significant association between psoriasis and the risk of dementia.

CONCLUSION

Most studies included in this review supported the hypothesis that psoriasis constitutes a risk factor for dementia. However, well-designed stratified cohort studies assessing both psoriasis severity and treatment status are still required to determine the real effect of psoriasis on the risk of dementia and its subtypes.

miR-146a aggravates cognitive impairment and Alzheimer disease-like pathology by triggering oxidative stress through MAPK signaling

INTRODUCTION

Mir-146a-5p has been widely recognized as a critical regulatory element in the immune response. However, recent studies have shown that miR-146a-5p may also be involved in the development of Alzheimer disease (AD). Regrettably, the related mechanisms are poorly understood. Here, we investigated the effects of miR-146a in mice models and SH-SY5Y cells treated with amyloid β (Aβ)1-42.

METHODS

To create a model of AD, SH-SY5Y cells were treated with Aβ1-42 and mice received intracerebroventricular injections of Aβ1-42. Then, the transcriptional levels of miR-146a were estimated by real-time PCR. We transiently transfected the miR-146a-5p mimic/inhibitor into cells and mice to study the role of miR-146a. The role of signaling pathways including p38 and reactive oxygen species (ROS) was studied by using specific inhibitors. Aβ and amyloid-beta precursor protein (APP)levels were measured by immunoblotting. Furthermore, Aβ expression was analyzed by immunofluorescence and histochemical examinations.

RESULTS

Aβ1-42-stimulated SH-SY5Y cells displayed increased transcriptional levels of miR-146a and APP. Moreover, the p38 MAPK signaling pathway and ROS production were activated upon stimulation with a miR-146a-5p mimic. However, treatment with a miR-146a-5p inhibitor decreased the levels of APP, ROS, and p-p38 MAPK. A similar phenomenon was also observed in the animals treated with Aβ1-42, in which miR-146a upregulation increased the expression of Aβ, p-p38, and ROS, while the inhibition of miR-146a had the opposite effect. This suggests that miR-146a increases Aβ deposition and ROS accumulation via the p-p38 signaling pathway.

CONCLUSIONS

Our research demonstrates that miR-146a-5pa increases Aβ deposition by triggering oxidative stress through activation of MAPK signaling.

Prognostic value of cerebrospinal fluid biomarkers in mild cognitive impairment due to Alzheimer disease

We performed a retrospective analysis of the patients assessed at our memory unit for whom Alzheimer disease (AD) cerebrospinal fluid biomarker results were available. We selected patients diagnosed with mild cognitive impairment due to AD (National Institute on Aging-Alzheimer's Association clinical criteria), confirmed neuropsychological deficit, a Global Deterioration Scale score of 3, and an abnormal profile of cerebrospinal fluid biomarkers. Of the 588 cases reviewed, 110 met the inclusion criteria. During follow-up, 50 cases (45.45%) progressed to dementia due to AD. Baseline levels of total and phosphorylated tau were higher in the group of patients that progressed to dementia than in those remaining with mild cognitive impairment. After adjusting for age, sex, history of hypertension, diabetes, and educational level, a 10% increase in total tau protein values was associated with a 7.60% increase in the risk of progression to dementia (hazard ratio: 2.22; 95% confidence interval, 1.28-3.84]; P =  .004). Among patients with mild cognitive impairment due to AD and abnormal cerebrospinal fluid biomarker profiles, progressively higher concentrations of total or phosphorylated tau were associated with increased risk of progression to dementia.

The CORCOBIA study: Cut-off points of Alzheimer's disease CSF biomarkers in a clinical cohort

INTRODUCTION

The analysis of the core biomarkers of Alzheimer's Disease (AD) in the cerebrospinal fluid (CSF) is recommended in the clinical units where it is available. Because of the absence of universal validated values, the determination of specific cut-off points for each center and its population is recommended. The main objective of the CORCOBIA study was to determine the cut-off points of core AD CSF biomarkers for several centers (Parc de Salut Mar, Barcelona and Hospital General de Granollers), which work with the same reference laboratory (Laboratori de Referència de Catalunya).

METHODS

Prospective study including cognitively unimpaired individuals (CU, n = 42), subjects with amnestic mild cognitive impairment (aMCI, n = 35) and patients with dementia due to Alzheimer's Disease (AD, n = 48), in whom clinical and neuropsychological assessment, neuroimaging, APOE genotyping and lumbar puncture to analyse amyloid beta peptides (Aβ42, Aβ40), total tau (tTau) and phosphorylated Tau (pTau181) using the Lumipulse G600II (Fujirebio) was performed. The values of sensitivity (SE), specificity (SP), predictive values and area under the curve (AUC) were calculated, determining the cut-off point according to the Youden index by comparing the CU and AD groups.

RESULTS

The resulting cut-offs and their AUC were the following: Aβ42 750 pg/mL (AUC 0.809); Aβ42/Aβ40 0.062 (AUC 0.78); pTau181 69.85 pg/mL (AUC 0.81); tTau 522.0 pg/mL (AUC 0.79); Aβ42/tTau 1.76 (AUC 0.86); Aβ42/pTau181 10.25 (AUC 0.86).

CONCLUSIONS

The determination of cut-off points of core AD CSF biomarkers for the participating centers allows a better diagnostic accuracy. The ratio CSF Aβ42/pTau181 shows the highest AUC and better balance between sensitivity and specificity.

Role of the gut microbiota in the development of various neurological diseases

INTRODUCTION

In recent years, the scientific evidence supporting a relationship between the microbiota and various diseases has increased significantly; this trend has also been observed for neurological diseases. This has given rise to the concept of the gut-brain axis and the idea of a relationship between the gut microbiota and several neurological diseases whose aetiopathogenesis is yet to be clearly defined.

DEVELOPMENT

We review the role of the gut microbiota in the gut-brain axis and analyse those neurological diseases in which alterations in the gut microbiota have been described as a result of human studies: specifically, Parkinson's disease, Alzheimer disease, amyotrophic lateral sclerosis, neuromyelitis optica, and multiple sclerosis.

CONCLUSIONS

The body of evidence linking the gut microbiota to various neurological diseases has grown considerably. Several interesting studies show a relationship between the gut microbiota and Parkinson's disease, Alzheimer disease, neuromyelitis optica, and multiple sclerosis, whereas other controversial studies implicate it in amyotrophic lateral sclerosis. Many of these studies place considerable emphasis on modulation of inflammation, particularly by bacteria capable of producing short-chain fatty acids. Despite these encouraging results, many questions remain, and there is a need to demonstrate causality, determine the role of fungi or viruses, and research possible treatment through diet, probiotics, or faecal microbiota transplantation.

Role of the gut microbiota in the development of various neurological diseases

INTRODUCTION

In recent years, the scientific evidence supporting a relationship between the microbiota and various diseases has increased significantly; this trend has also been observed for neurological diseases. This has given rise to the concept of the gut-brain axis and the idea of a relationship between the gut microbiota and several neurological diseases whose aetiopathogenesis is yet to be clearly defined.

DEVELOPMENT

We review the role of the gut microbiota in the gut-brain axis and analyse those neurological diseases in which alterations in the gut microbiota have been described as a result of human studies: specifically, Parkinson's disease, Alzheimer disease, amyotrophic lateral sclerosis, neuromyelitis optica, and multiple sclerosis.

CONCLUSIONS

The body of evidence linking the gut microbiota to various neurological diseases has grown considerably. Several interesting studies show a relationship between the gut microbiota and Parkinson's disease, Alzheimer disease, neuromyelitis optica, and multiple sclerosis, whereas other controversial studies implicate it in amyotrophic lateral sclerosis. Many of these studies place considerable emphasis on modulation of inflammation, particularly by bacteria capable of producing short-chain fatty acids. Despite these encouraging results, many questions remain, and there is a need to demonstrate causality, determine the role of fungi or viruses, and research possible treatment through diet, probiotics, or faecal microbiota transplantation.

Pharmacogenetic studies in Alzheimer disease

INTRODUCTION

Alzheimer disease (AD) is the most common cause of dementia and is considered one of the main causes of disability and dependence affecting quality of life in elderly people and their families. Current pharmacological treatment includes acetylcholinesterase inhibitors (donepezil, galantamine, rivastigmine) and memantine; however, only one-third of patients respond to treatment. Genetic factors have been shown to play a role in this inter-individual variability in drug response.

DEVELOPMENT

We review pharmacogenetic reports of AD-modifying drugs, the pharmacogenetic biomarkers included, and the phenotypes evaluated. We also discuss relevant methodological considerations for the design of pharmacogenetic studies into AD. A total of 33 pharmacogenetic reports were found; the majority of these focused on the variability in response to and metabolism of donepezil. Most of the patients included were from Caucasian populations, although some studies also include Korean, Indian, and Brazilian patients. CYP2D6 and APOE are the most frequently studied biomarkers. The associations proposed are controversial.

CONCLUSIONS

Potential pharmacogenetic biomarkers for AD have been identified; however, it is still necessary to conduct further research into other populations and to identify new biomarkers. This information could assist in predicting patient response to these drugs and contribute to better treatment decision-making in a context as complex as aging.

Polymorphisms of apolipoprotein E in the Afro-descendant population of Buenaventura, Colombia

OBJETIVES

To estimate the frequency distribution, both allelic and genotypic, of the APOE gene in the Afro-descendant population of Buenaventura, Colombia.

METHODS

Three hundred and forty-eight Afro-descendant individuals were analysed and the APOE locus was genotyped by PCR-RFLP. The allelic and genotypic frequencies were established by direct counting and the Hardy-Weinberg equilibrium was evaluated through χ² test. The frequencies obtained in this study were compared with frequencies reported for other Colombian populations through the Fisher's exact test.

RESULTS

The following allelic frequencies were observed: E3, 70.8%; E4, 21.4%, and E2, 7.8%. The genotypic frequencies were: E3/E3, 51.1%; E3/E4, 27.3%; E2/E3, 12.1%; E4/E4, 6%; E2/E4, 3.5%, and E2/E2, 0%. The entire examined population was found in Hardy-Weinberg equilibrium (P=.074), and significant differences were found in the allele E4 when comparing this population with the Amerindian and mestizo populations of Bogotá, Quindío, Centro-Oriente, Valle del Cauca, Barranquilla and Medellín (P≤ 0.0345).

CONCLUSIONS

The allelic frequencies observed in this study were significantly different from the frequencies reported in other Colombian populations. The high representativeness of the E4 and E2 alleles validates the hypothesis that there are micro-evolutionary processes that have been acting on their frequencies and could be associated with susceptibility to neuropsychiatric diseases such as Alzheimer's disease, metabolic alterations of fats and/or coronary artery disease.

Peripheral blood lymphocyte phenotypes in Alzheimer and Parkinson's diseases

INTRODUCTION

Neuroinflammation is involved in the pathophysiology of various neurological disorders, in particular Alzheimer disease (AD) and Parkinson's disease (PD). Alterations in the blood-brain barrier may allow peripheral blood lymphocytes to enter the central nervous system; these may participate in disease pathogenesis.

OBJECTIVE

To evaluate the peripheral blood lymphocyte profiles of patients with AD and PD and their association with the disease and its progression.

METHODS

The study included 20 patients with AD, 20 with PD, and a group of healthy individuals. Ten of the patients with AD and 12 of those with PD were evaluated a second time 17 to 27 months after the start of the study. Lymphocyte subpopulations and their activation status were determined by flow cytometry. All patients underwent neurological examinations using internationally validated scales.

RESULTS

Compared to healthy individuals, patients with AD and PD showed significantly higher levels of activated lymphocytes, lymphocytes susceptible to apoptosis, central memory T cells, and regulatory T and B cells. As the diseases progressed, there was a significant decrease in activated cells (CD4+ CD38+ and CD8+ CD38+ in PD and AD, CD4+ CD69+ and CD8+ CD69+ in PD), T cells susceptible to apoptosis, and some regulatory populations (CD19+ CD5+ IL10+ in PD and AD, CD19+ CD5+ IL10+ FoxP3+, CD4+ FoxP3+ CD25+ CD45RO+ in PD). In patients with AD, disease progression was associated with lower percentages of CD4+ CD38+ cells and higher percentages of effector CD4 cells at the beginning of the study. Significant differences were observed between both diseases.

CONCLUSIONS

This study provides evidence of changes in peripheral blood lymphocyte phenotypes associated with AD and PD and their severity. Considering effective blood-brain communication, our results open new avenues of research into immunomodulation therapies to treat these diseases.

Peripheral blood lymphocyte phenotypes in Alzheimer and Parkinson's diseases

INTRODUCTION

Neuroinflammation is involved in the pathophysiology of various neurological disorders, in particular Alzheimer disease (AD) and Parkinson's disease (PD). Alterations in the blood-brain barrier may allow peripheral blood lymphocytes to enter the central nervous system; these may participate in disease pathogenesis.

OBJECTIVE

To evaluate the peripheral blood lymphocyte profiles of patients with AD and PD and their association with the disease and its progression.

METHODS

The study included 20 patients with AD, 20 with PD, and a group of healthy individuals. Ten of the patients with AD and 12 of those with PD were evaluated a second time 17 to 27 months after the start of the study. Lymphocyte subpopulations and their activation status were determined by flow cytometry. All patients underwent neurological examinations using internationally validated scales.

RESULTS

Compared to healthy individuals, patients with AD and PD showed significantly higher levels of activated lymphocytes, lymphocytes susceptible to apoptosis, central memory T cells, and regulatory T and B cells. As the diseases progressed, there was a significant decrease in activated cells (CD4+ CD38+ and CD8+ CD38 + in PD and AD, CD4+ CD69+ and CD8+ CD69+ in PD), T cells susceptible to apoptosis, and some regulatory populations (CD19+ CD5+ IL10+ in PD and AD, CD19+ CD5+ IL10+ FoxP3+, CD4+ FoxP3+ CD25+ CD45RO+ in PD). In patients with AD, disease progression was associated with lower percentages of CD4+ CD38+ cells and higher percentages of effector CD4 cells at the beginning of the study. Significant differences were observed between both diseases.

CONCLUSIONS

This study provides evidence of changes in peripheral blood lymphocyte phenotypes associated with AD and PD and their severity. Considering effective blood-brain communication, our results open new avenues of research into immunomodulation therapies to treat these diseases.

Comparative study of the word capacity and episodic memory of patients with degenerative dementia

INTRODUCTION

Although the absence of memory impairment was considered among the diagnostic criteria to differentiate Alzheimer's disease (AD) from Behavioural Variant of Frontotemporal Dementia (bvFTD), current and growing evidence indicates that a significant percentage of cases of bvFTD present with episodic memory deficits. In order to compare the performance profile of the naming capacity and episodic memory in patients with AD and bvFTD the present study was designed.

METHODS

Cross-sectional and analytical study with control group (32 people). The study included 42 people with probable AD and 22 with probable bvFTD, all over 60 years old. Uniform Data Set instruments validated in Spanish were used: Multilingual Naming Test (MINT), Craft-21 history and Benson's complex figure, among others.

RESULTS

A higher average age was observed among the patients with AD. The naming capacity was much lower in patients with bvFTD compared to patients with AD, measured according to the MINT and the nouns/verbs naming coefficient. All patients with bvFTD, 73.81% of those with AD and only 31.25% of the control group failed to recognise Benson's complex figure. All differences were statistically significant (p < 0.001).

RESULTS

This study confirms the amnesic profile of patients with AD and reveals the decrease in naming capacity in patients with bvFTD, an area of ​​language that is typically affected early on with executive functions, according to recent findings.

CONCLUSIONS

Patients with AD perform worse in verbal and visual episodic memory tasks, while patients with bvFTD perform worse in naming tasks. These findings open the possibility of exploring the mechanisms of prefrontal participation in episodic memory, typically attributed to the hippocampus.

Etiology, risk factors, treatments and current status of Alzheimer's disease in Mexico

Alzheimer's disease is a neurodegenerative disorder whose etiology continues to be discussed, to the point that there are different hypotheses that seek to clarify it, in addition to the fact that, given its multifactorial nature, there are different risk factors associated with its development. As regards diagnosis, advances in molecule detection techniques at femtomolar scales have allowed to distinguish between healthy and diseased subjects at relatively early stages, although there is still much to be done. Aducanumab is a monoclonal antibody targeted against Aβ, whose marketing approval by the Food and Drug Administration has been questioned by the international medical community, given the controversial results in clinical trials. Approval of this antibody as a disease-modifying treatment for Alzheimer's disease opens the door to continue using this type of treatments, but with different therapeutic targets, such as, for example, tau protein. Finally, given the population tendency towards longevity, conditions such as Alzheimer's disease are gaining epidemiological importance, which is why it is imperative to analyze and link what is being done in the social, familiar, clinical and research fields and, most importantly, to find those areas of opportunity for the benefit of the patient.

[Depression and its relationship with mild cognitive impairment and Alzheimer disease: A review study]

The objective of the present study was to determine whether depression precedes Mild cognitive impairment (MCI) as a risk factor or as a predictor in Alzheimer's disease (AD). A systematic review of observational studies (cross-sectional and cohort or follow-up) was carried out using the PRISMA search algorithm, for clinical markers in MCI and AD, in the Science Direct, Springer, Scopus and Proquest databases. The study eligibility criteria included inclusion criteria: of types of documents, articles of primary studies, type of source scientific journals, published in the English language, from January 2010 to April 2020, in patients with MCI and AD and in the group of age included in people with a minimum age range of 45years. Exclusion criteria were: publications older than 10years because the aim of the article was to explore recent studies, secondary research studies, type of report document, languages other than English. 3385 articles were identified, of which 30 articles were finally selected. It was found that there is an association between depression and AD, but properly as a risk factor but not, as a predictor or clinical marker of the development of AD. The degree of association is greater when they present depressive symptoms and simultaneously report subjective memory complaints or the presence of MCI.

Blood biomarkers in Alzheimer's disease

INTRODUCTION

Early diagnosis of Alzheimer disease (AD) through the use of biomarkers could assist in the implementation and monitoring of early therapeutic interventions, and has the potential to significantly modify the course of the disease.

DEVELOPMENT

The classic cerebrospinal fluid and approved structural and functional neuroimaging biomarkers are of limited clinical application given their invasive nature and/or high cost. The identification of more accessible and less costly biomarkers, such as blood biomarkers, would increase their use in clinical practice. We review the available published evidence on the main blood biochemical biomarkers potentially useful for diagnosing AD.

CONCLUSIONS

Blood biomarkers are more cost- and time-effective than CSF biomarkers. However, immediate applicability in clinical practice is relatively unlikely. The main limitations come from the difficulty of measuring and standardising thresholds between different laboratories and the failure to replicate results. Of all the molecules studied, apoptosis and neurodegeneration biomarkers and the biomarker panels obtained through "omics" approaches, such as isolated or combined metabolomics, offer the most promising results.

Nutritional status assessment in Alzheimer disease and its influence on disease progression

INTRODUCTION

Nutritional deficiencies are frequent in Alzheimer disease (AD), even in early stages. Nutritional impairment (NI) may be associated with faster disease progression. The objective of this study was to describe the frequency of NI and the associated risk factors at the time of diagnosis and to analyse its influence on subsequent progression.

METHODS

We performed a prospective, multicentre, observational study of patients recently diagnosed with prodromal AD (pAD) or dementia due to AD (ADd). Two clinical assessments were conducted over a period of 18 months. The Mini Nutritional Assessment test (MNA; score range, 0-30; cut-off point for NI, < 24) was used to estimate nutritional status. Progression was defined as an increase of ≥ 3 points on the Clinical Dementia Rating-sum of boxes test.

RESULTS

The sample included 50 patients with pAD (mean [standard deviation] age, 76.1 [5.3] years; 68% women), and 127 with ADd (80 [5.9] years; 72.4% women). A total of 141 (79.7%) completed both evaluations. The prevalence of NI was 28.2% (24% for pAD, 29.9% for ADd; P = .43), with the majority (92%) at risk of malnutrition. NI was associated with female sex (odds ratio [OR]: 4.2; 95% confidence interval [CI]: 1.7-10.5; P < .001) and greater behavioural involvement (OR: 5.8; 95% CI: 2.6-12.7; P < .001). A larger proportion of patients with progression was observed among those with NI than among those with normal nutritional status (50% vs 28.7%, P < .05; ADd: 53.6% vs 31.8%, P < .05; pAD: 41.7% vs 22.9%, P = .21). Greater cognitive impairment (OR: 2.1; 95% CI: 1.03-4.4; P < .05) and NI (OR: 2.4; 95% CI: 1.1-5.1; P < .05) were independent risk factors for disease progression.

CONCLUSIONS

NI is highly prevalent in patients with AD. Assessing nutritional status at the time of diagnosis may enable identification of patients at greater risk of disease progression.

[Experience with 4 clinical cases. Traumatic encephalopathy may be associated with a single traumatic brain injury?]

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease that affects people who had repetitive head trauma. Also, in single traumatic brain injury (TBI), changes may be found during the follow-up visits. We present four clinical cases of patients visited at the Institut Guttmann clinic between 2017 and 2019. They were affected by mild sequelae of severe and unique TBI who have subsequently developed a neurodegenerative disease without a specific diagnosis, and who could meet clinical criteria for chronic traumatic encephalopathy syndrome. Rehabilitation doctors are the professionals with the greatest possibility of identifying a suggestive clinic of this pathology, they can order the appropriate studies and indicate the new rehabilitation goals according to the new neurological situation.

The potential diagnostic accuracy of circulating microRNAs for Alzheimer's disease: A meta-analysis

BACKGROUND & OBJECTIVE

Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative disease that seriously affects cognitive ability and has become a key public health problem. Many studies have identified the possibility of peripheral blood microRNA as effective non-invasive biomarkers for AD diagnosis, but the results are inconsistent. Therefore, we carried out this meta-analysis to evaluate the diagnostic accuracy of circulating microRNAs in the diagnosis of AD patients.

METHODS

We performed a systematic literature search of the following databases: PubMed, EMBASE, Web of Science, Cochrane Library, Wanfang database and China National Knowledge Infrastructure, updated to March 15, 2021. A random effects model was used to pool the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and area under the curve. Meta-regression and subgroup analysis were performed to explore the sources of heterogeneity, and Deeks' funnel plot was used to assess whether there was publication bias.

RESULTS

62 studies from 18 articles were included in this meta-analysis. The pooled sensitivity was 0.82 (95% CI: 0.78-0.85), specificity was 0.80 (95% CI: 0.76-0.83), PLR was 4. 1 (95% CI: 3.4-4.9), NLR was 0.23 (95% CI: 0.19-0.28), DOR was 18 (95% CI: 13-25) and AUC was 0.88 (95% CI: 0.84-0.90). Subgroup analysis shows that the microRNA clusters of plasma type performed a better diagnostic accuracy of AD patients. In addition, publication bias was not found.

CONCLUSIONS

Circulating microRNAs can be used as a promising non-invasive biomarker in AD diagnosis.

[Effects of the use of 17 β-estradiol and genistein in Alzheimer's disease in women with menopause]

The use of 17 β-estradiol and genistein in women with menopause helps in the reduction of vasomotor symptoms and cognitive improvement. There is evidence on the use of certain flavonoids such as genistein, which has a potentially neuroprotective role in neurodegenerative diseases such as Alzheimer's. Scientific evidence on the effects of phytoestrogens and genistein during menopause and their effect on cognition are scarce, however, in the present review it was found that the intervention with 17 β-estradiol has positive effects on cognition in women with Alzheimer's disease. In addition, the use of genistein, daidzein or any supplement based on isoflavones may influence vasomotor symptoms. 17 β-estradiol supplements in women in early menopause and with some degree of cognitive impairment may have beneficial effects.

Association between psoriasis and dementia: A systematic review

INTRODUCTION

Risk factors for dementia include genetic factors, aging, environmental factors, certain diseases, and unhealthy lifestyle; most types of dementia share a common chronic systemic inflammatory phenotype. Psoriasis is also considered to be a chronic systemic inflammatory disease. It has been suggested that psoriasis may also contribute to the risk of dementia. The aim of this study was to systematically review the literature on the association between psoriasis and dementia.

DEVELOPMENT

Articles were selected according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched the PubMed and Web of Science databases to identify articles published in peer-reviewed journals and studying the association between psoriasis and dementia. Studies meeting the inclusion criteria were reviewed. We used the Newcastle-Ottawa Scale to assess the quality of each study. After applying the inclusion and exclusion criteria, we included 8 studies for review, 3 of which were found to present a higher risk of bias. Six of the 8 studies supported the hypothesis that prior diagnosis of psoriasis increases the risk of dementia; one study including only a few cases reported that psoriasis decreased the risk of dementia, and one study including relatively young patients found no significant association between psoriasis and the risk of dementia.

CONCLUSION

Most studies included in this review supported the hypothesis that psoriasis constitutes a risk factor for dementia. However, well-designed stratified cohort studies assessing both psoriasis severity and treatment status are still required to determine the real effect of psoriasis on the risk of dementia and its subtypes.

miR-146a aggravates cognitive impairment and Alzheimer disease-like pathology by triggering oxidative stress through MAPK signaling

INTRODUCTION

Mir-146a-5p has been widely recognized as a critical regulatory element in the immune response. However, recent studies have shown that miR-146a-5p may also be involved in the development of Alzheimer disease (AD). Regrettably, the related mechanisms are poorly understood. Here, we investigated the effects of miR-146a in mice models and SH-SY5Y cells treated with amyloid β (Aβ)1-42.

METHODS

To create a model of AD, SH-SY5Y cells were treated with Aβ1-42 and mice received intracerebroventricular injections of Aβ1-42. Then, the transcriptional levels of miR-146a were estimated by real-time PCR. We transiently transfected the miR-146a-5p mimic/inhibitor into cells and mice to study the role of miR-146a. The role of signaling pathways including p38 and reactive oxygen species (ROS) was studied by using specific inhibitors. Aβ and amyloid-beta precursor protein (APP)levels were measured by immunoblotting. Furthermore, Aβ expression was analyzed by immunofluorescence and histochemical examinations.

RESULTS

Aβ1-42-stimulated SH-SY5Y cells displayed increased transcriptional levels of miR-146a and APP. Moreover, the p38 MAPK signaling pathway and ROS production were activated upon stimulation with a miR-146a-5p mimic. However, treatment with a miR-146a-5p inhibitor decreased the levels of APP, ROS, and p-p38 MAPK. A similar phenomenon was also observed in the animals treated with Aβ1-42, in which miR-146a upregulation increased the expression of Aβ, p-p38, and ROS, while the inhibition of miR-146a had the opposite effect. This suggests that miR-146a increases Aβ deposition and ROS accumulation via the p-p38 signaling pathway.

CONCLUSIONS

Our research demonstrates that miR-146a-5pa increases Aβ deposition by triggering oxidative stress through activation of MAPK signaling.

Polymorphisms of apolipoprotein E in the Afro-descendant population of Buenaventura, Colombia

OBJETIVES

To estimate the frequency distribution, both allelic and genotypic, of the APOE gene in the Afro-descendant population of Buenaventura, Colombia.

METHODS

Three hundred and forty-eight Afro-descendant individuals were analysed and the APOE locus was genotyped by PCR-RFLP. The allelic and genotypic frequencies were established by direct counting and the Hardy-Weinberg equilibrium was evaluated through χ2 test. The frequencies obtained in this study were compared with frequencies reported for other Colombian populations through the Fisher's exact test.

RESULTS

The following allelic frequencies were observed: E3, 70.8%; E4, 21.4%, and E2, 7.8%. The genotypic frequencies were: E3/E3, 51.1%; E3/E4, 27.3%; E2/E3, 12.1%; E4/E4, 6%; E2/E4, 3.5%, and E2/E2, 0%. The entire examined population was found in Hardy-Weinberg equilibrium (P=.074), and significant differences were found in the allele E4 when comparing this population with the Amerindian and mestizo populations of Bogotá, Quindío, Centro-Oriente, Valle del Cauca, Barranquilla and Medellín (P≤ 0.0345).

CONCLUSIONS

The allelic frequencies observed in this study were significantly different from the frequencies reported in other Colombian populations. The high representativeness of the E4 and E2 alleles validates the hypothesis that there are micro-evolutionary processes that have been acting on their frequencies and could be associated with susceptibility to neuropsychiatric diseases such as Alzheimer's disease, metabolic alterations of fats and/or coronary artery disease.

Comparative Study of the Word Capacity and Episodic Memory of Patients with Degenerative Dementia

INTRODUCTION

Although the absence of memory impairment was considered among the diagnostic criteria to differentiate Alzheimer's disease (AD) from Behavioural Variant of Frontotemporal Dementia (bvFTD), current and growing evidence indicates that a significant percentage of cases of bvFTD present with episodic memory deficits. In order to compare the performance profile of the naming capacity and episodic memory in patients with AD and bvFTD the present study was designed.

METHODS

Cross-sectional and analytical study with control group (32 people). The study included 42 people with probable AD and 22 with probable bvFTD, all over 60 years old. Uniform Data Set instruments validated in Spanish were used: Multilingual Naming Test (MINT), Craft-21 history and Benson's complex figure, among others.

RESULTS

A higher average age was observed among the patients with AD. The naming capacity was much lower in patients with bvFTD compared to patients with AD, measured according to the MINT and the nouns/verbs naming coefficient. All patients with bvFTD, 73.81% of those with AD and only 31.25% of the control group failed to recognise Benson's complex figure. All differences were statistically significant (p <0.001).

RESULTS

This study confirms the amnesic profile of patients with AD and reveals the decrease in naming capacity in patients with bvFTD, an area of language that is typically affected early on with executive functions, according to recent findings.

CONCLUSIONS

Patients with AD perform worse in verbal and visual episodic memory tasks, while patients with bvFTD perform worse in naming tasks. These findings open the possibility of exploring the mechanisms of prefrontal participation in episodic memory, typically attributed to the hippocampus.

Prognostic value of cerebrospinal fluid biomarkers in mild cognitive impairment due to Alzheimer disease

We performed a retrospective analysis of the patients assessed at our memory unit for whom Alzheimer disease (AD) cerebrospinal fluid biomarker results were available. We selected patients diagnosed with mild cognitive impairment due to AD (National Institute on Aging-Alzheimer's Association clinical criteria), confirmed neuropsychological deficit, a Global Deterioration Scale score of 3, and an abnormal profile of cerebrospinal fluid biomarkers. Of the 588 cases reviewed, 110 met the inclusion criteria. During follow-up, 50 cases (45.45%) progressed to dementia due to AD. Baseline levels of total and phosphorylated tau were higher in the group of patients that progressed to dementia than in those remaining with mild cognitive impairment. After adjusting for age, sex, history of hypertension, diabetes, and educational level, a 10% increase in total tau protein values was associated with a 7.60% increase in the risk of progression to dementia (hazard ratio: 2.22; 95% confidence interval, 1.28-3.84]; P = .004). Among patients with mild cognitive impairment due to AD and abnormal cerebrospinal fluid biomarker profiles, progressively higher concentrations of total or phosphorylated tau were associated with increased risk of progression to dementia.

Attentional networks in neurodegenerative diseases: anatomical and functional evidence from the Attention Network Test

INTRODUCTION

Understanding alterations to brain anatomy and cognitive function associated with neurodegenerative diseases remains a challenge for neuroscience today. In experimental neuroscience, several computerised tests have been developed to contribute to our understanding of neural networks involved in cognition. The Attention Network Test (ANT) enables us to measure the activity of 3 attentional networks (alertness, orienting, and executive function).

OBJECTIVES

The main aim of this review is to describe all the anatomical and functional alterations found in diverse neurological diseases using the ANT.

MATERIAL AND METHODS

We collected studies published since 2010 in the PubMed database that employed the ANT in different neurological diseases. Thirty-two articles were obtained, addressing multiple sclerosis, epilepsy, and Parkinson's disease, among other disorders.

CONCLUSIONS

Some of the anatomical structures proposed in the 3 attentional networks model were confirmed. The most relevant structures in the alertness network are the prefrontal cortex, parietal region, thalamus, and cerebellum. The thalamus is also relevant in the orienting network, together with posterior parietal regions. The executive network does not depend exclusively on the prefrontal cortex and anterior cingulate cortex, but also involves such subcortical structures as the basal ganglia and cerebellum and their projections towards the entire cortex.

[Pre-death grief in caregivers of Alzheimer patients. A validation of a guide]

INTRODUCTION

The pre-death grief in family caregivers (FC) of people with Alzheimer's disease has not been sufficiently treated in studies on this group. Thus, the design and validation of informative printed materials is relevant due to its important implications for the well-being of these FCs and their training in the proper performance of their role. The objective was to design and validate a booklet aimed at informing FCs about this topic, as well as the procedure for its dissemination and use.

MATERIALS AND METHODS

After a review of the literature, a booklet and a questionnaire were designed to determine the acceptability and dissemination procedure and use of the booklet by 73 professionals working with FCs. With the suggestions made, modifications were made to both the content and format of the booklet.

RESULTS

The questionnaire used presented adequate content validity and reliability in its different sections (α=0.793 and α=0.888). The level of acceptability of the booklet was high by professionals (83.85% of total score). Its dissemination was especially valued in the initial stages of the disease, and its use in therapeutic and supportive group contexts, with professional advice.

CONCLUSIONS

The study made it possible to verify the relevance and acceptability of a booklet as a training resource for FCs about pre-death grief, making it a useful tool for professionals that work in this area of great relevance.

[The cognitive-behavioural impact of hypertension]

Arterial hypertension is considered the main modifiable vascular risk factor that causes silent damage to brain vessels. This vascular brain injury could be the common nucleus that justifies the cognitive (cognitive impairment, dementia and Alzheimer's disease) and behavioural symptoms (late-life depression) of target organ damage mediated-hypertension. Incomplete knowledge about the complex pathophysiology that links hypertension with cognitive-behavioural changes is overlooking brain involvement and underestimating cardio and cerebrovascular risk. The confluence of cognitive impairment, depression and arterial hypertension in elderly adults, warns of the need for a comprehensive evaluation to plan treatment, improve prognosis and contribute to reducing the risk of dementia and its incidence.

Association between benzodiazepine use and development of dementia

OBJECTIVE

To evaluate the association between use of benzodiazepines and incident dementia.

METHODS

Analytical prospective nested case-control study for which the Spanish database for pharmacoepidemiological research in primary care (BIFAP) of the Spanish Agency of Medicines and Medical Devices (AEMPS) was used. A total of 15,212 subjects diagnosed with dementia of the Alzheimer type and 62,397 controls were identified. Exposure was retrieved retrospectively with a 3-year lag time before the index date. Adjusted odd ratios (OR) were calculated.

RESULTS

Benzodiazepines use increased the risk of suffering Alzheimer's disease (OR=1.05, 95% CI, 1.01-1.10). No statistical differences were shown between short-acting and long-acting drugs. The risk is more evident with longer exposure times.

CONCLUSIONS

There seems to be a weak association between benzodiazepine use and the development of dementia, the risk increases with greater exposure.

Validity of a computerised population registry of dementia based on clinical databases

INTRODUCTION

The handling of information through digital media allows innovative approaches for identifying cases of dementia through computerised searches within the clinical databases that include systems for coding diagnoses. The aim of this study was to analyse the validity of a dementia registry in Gipuzkoa based on the administrative and clinical databases existing in the Basque Health Service.

METHODS

This is a descriptive study based on the evaluation of available data sources. First, through review of medical records, the diagnostic validity was evaluated in two samples of cases identified and not identified as dementia. The sensitivity, specificity and positive and negative predictive value of the diagnosis of dementia were measured. Subsequently, the cases of living dementia in December 31, 2016 were searched in the entire Gipuzkoa population to collect sociodemographic and clinical variables.

RESULTS

The validation samples included 986 cases and 327 no cases. The calculated sensitivity was 80.2% and the specificity was 99.9%. The negative predictive value was 99.4% and positive value was 95.1%. The cases in Gipuzkoa were 10 551, representing 65% of the cases predicted according to the literature. Antipsychotic medication were taken by a 40% and a 25% of the cases were institutionalised.

CONCLUSIONS

A registry of dementias based on clinical and administrative databases is valid and feasible. Its main contribution is to show the dimension of dementia in the health system.

Nutritional status assessment in Alzheimer disease and its influence on disease progression

INTRODUCTION

Nutritional deficiencies are frequent in Alzheimer disease (AD), even in early stages. Nutritional impairment (NI) may be associated with faster disease progression. The objective of this study was to describe the frequency of NI and the associated risk factors at the time of diagnosis and to analyse its influence on subsequent progression.

METHODS

We performed a prospective, multicentre, observational study of patients recently diagnosed with prodromal AD (pAD) or dementia due to AD (ADd). Two clinical assessments were conducted over a period of 18months. The Mini Nutritional Assessment test (MNA; score range, 0-30; cut-off point for NI, <24) was used to estimate nutritional status. Progression was defined as an increase of ≥3points on the Clinical Dementia Rating-sum of boxes test.

RESULTS

The sample included 50 patients with pAD (mean [standard deviation] age, 76.1 [5.3] years; 68% women), and 127 with ADd (80 [5.9] years; 72.4% women). A total of 141 (79.7%) completed both evaluations. The prevalence of NI was 28.2% (24% for pAD, 29.9% for ADd; P=.43), with the majority (92%) at risk of malnutrition. NI was associated with female sex (odds ratio [OR]: 4.2; 95% confidence interval [CI]: 1.7-10.5; P<.001) and greater behavioural involvement (OR: 5.8; 95%CI: 2.6-12.7; P<.001). A larger proportion of patients with progression was observed among those with NI than among those with normal nutritional status (50% vs 28.7%, P<.05; ADd: 53.6% vs 31.8%, P<.05; pAD: 41.7% vs 22.9%, P=.21). Greater cognitive impairment (OR: 2.1; 95%CI: 1.03-4.4; P<.05) and NI (OR: 2.4; 95%CI: 1.1-5.1; P<.05) were independent risk factors for disease progression.

CONCLUSIONS

NI is highly prevalent in patients with AD. Assessing nutritional status at the time of diagnosis may enable identification of patients at greater risk of disease progression.

[Mobile applications in alzheimer's disease. A systematic review of the literature]

INTRODUCTION

New treatment options are emerging to treat Alzheimer's disease (AE) within the field of smartphone technologies.

OBJECTIVE

To carry out a systematic review of the literature on the use of mobile applications in AE and to review the app markets in order to extract the main apps, with a view to classifying the describing them in the context of AE.

MATERIAL AND METHODS

A systematic review was carried out from 2000 until 2018 on apps for AE. At the same time, a search for mobile applications was conducted in the main mobile application markets.

RESULTS

A total of 294 mobile applications were found, which were classified as follows: 178 with potential utility for AE and 116 with a specific design for AE (73 information apps, 8 assessment apps, 31 treatment apps, 3 information and assessment and one assessment and treatment app).

CONCLUSIONS

There are multiple apps with potential utility or a specific design for AE. However, the limited number of scientific articles and their poor quality make it impossible to generalise their use. Consequently, future research is needed by health agencies in the context of AE.

Retinal glial changes in Alzheimer's disease - A review

Alzheimer's disease (AD) is a neurodegenerative dementia characterized by the deposition of extracellular β-amyloid (Aβ) plaques and the presence of neurofibrillary tangles. Until now, the techniques used to analyze these deposits have been difficult to access, invasive, and expensive. This leads us to consider new access routes to the central nervous system (CNS), allowing us to diagnose the disease before the first symptoms appear. Recent studies have shown that microglial and macroglial cell activation could play a role in the development of this disease. Glial cells in the CNS can respond to various damages, such as neurodegenerative pathologies, with morphological and functional changes. These changes are a common feature in neurodegenerative diseases, including AD. The retina is considered an extension of the CNS and has a population of glial cells similar to that of the CNS. When glial cells are activated, various molecules are released and changes in glial cell expression occur, which can be indicators of neuronal damage. The objective of this review is to compile the most relevant findings in the last 10 years relating to alterations in the eye in AD, and the role that glial cells play in the degenerative process in the retina in the context of neurodegeneration.

Association between white matter lesions and the cerebral glucose metabolism in patients with cognitive impairment

AIM

White matter lesions (WMLs), detected as hyperintensities on T2-weighted MRI, represent small vessel disease in the brain and are considered a potential risk factor for memory and cognitive impairment. It has not been sufficiently evident that cognitive impairment in patients with Alzheimer's disease is caused by WMLs as well as β-amyloid (Aβ) pathology. The aim of this study was to evaluate relationship between WMLs and cerebral glucose metabolism in patients with cognitive impairment after adjustment of cerebral Aβ burden.

MATERIALS AND METHODS

Eighty-three subjects with cognitive performance ranging from normal to dementia, who underwent brain MRI and ¹⁸F-florbetaben positron emission tomography (PET) and ¹⁸F-fluorodeoxyglucose PET, were included in this cross-sectional study. The Fazekas scale was used to quantify WMLs on brain T2-weighted MRI. The cerebral Aβ burden and cerebral glucose metabolism were quantitatively estimated using volume-of-interest analysis. Differences in the regional cerebral glucose metabolism were evaluated between low-WML (Fazekas scale<2) and high-WML (Fazekas scale≥2) groups. Multiple linear regression analysis adjusted for age, sex and cerebral Aβ burden was performed to evaluate the relationship between the Fazekas scale score and cerebral glucose metabolism.

RESULTS

The regional cerebral glucose metabolism for the bilateral frontal, temporal, and parietal cortices, and limbic lobes in the high-WML group were significantly lower than those in the low-WML group. There were significant negative correlations between the Fazekas scale score and regional cerebral glucose metabolism in the bilateral frontal, bilateral temporal and left parietal cortices, and bilateral limbic lobes. Multiple linear regression analysis revealed that the Fazekas scale score was an independent determinant of the glucose metabolism in the bilateral frontal and temporal cortices and limbic lobes.

CONCLUSIONS

WMLs are associated with decreased cerebral glucose metabolism. Our findings suggest that small vessel disease, as well as Aβ pathology, may contribute to cognitive impairment in patients with Alzheimer's disease.

[Alzheimer's disease and the quality of life of the informal caregiver]

BACKGROUND

Along with an ageing population, a higher incidence of chronic diseases leads to increasingly complex health profiles. The relationship between survival, dependence, and social and demographic trends affecting caregiving, has led to an increase in the negative consequences associated with care provision. In this context, an assessment needs to be made on the impact that caregiving has on the well-being of the caregivers. The main aim of this article is to study the factors that determine the Quality of Life (QoL) of those who provide informal care to people suffering from Alzheimer's disease (AD).

METHODS

A total of 175 caregivers of people with AD were recruited through the Galician Association for Relatives with Alzheimer. These caregivers completed a questionnaire (EQ-5D) that gathered sociodemographic and health variables, QoL, and care characteristics. Multiple regression models were calculated to explain the QoL of the caregivers.

RESULTS

Of the five dimensions that the EQ-5D used to describe health, anxiety/depression was the one that concerned the largest percentage of caregivers who declared the highest levels of severity. The key variables for explaining QoL are those related to caregiver health status, periods of rest during caregiving, and the presence of a second caregiver.

CONCLUSIONS

Maintaining a minimal QoL among the caregivers not only has repercussions on the caregivers themselves, but also has an impact on those receiving care and the entire health system, which would have to find replacements for those informal caregivers.

[Mortalidad por enfermedad de Alzheimer en México de 1980 a 2014]

Background

Dementias are rarely considered to be a main cause of death; therefore there are only few studies on Alzheimer's mortality covering long periods.

Objective

To describe mortality from Alzheimer's disease in México for the period from 1980 to 2014.

Method

Cross-sectional study where, with official mortality data in Mexico according to codes 331.0 and G30, respectively, of the 9^th and 10^th revisions of the International Statistical Classification of Diseases and Related Health Problems, crude and standardized Alzheimer's disease mortality rates were obtained, both nationally and by states.

Results

From almost being inexistent, deaths from Alzheimer's disease went to a rate of 65.12 per 1000 females and 43.66 per 1000 males in the 2010-2014 five-year period. Throughout the study period, the age group with highest mortality rates for this cause were those older than 80 years, with 0.29 per 100,000 population in 1980-1984 and 55.02 in 100,000 in the 2010-2014 period. The region with the highest mortality was the northwest, with rates higher than 2.28 per 100,000 population.

Conclusions

Mortality from Alzheimer's disease is a public health problem in Mexico with a growing trend, especially among women and older adults. Early diagnostic measures and opportune treatment are required in primary care in order to reduce this problem.

Magnetic resonance imaging in dementia

OBJECTIVE

To describe and illustrate the key findings on structural magnetic resonance imaging (MRI) in the most common dementias of neurodegenerative origin: Alzheimer's disease, vascular dementia, dementia with Lewy bodies, variants of frontotemporal dementia, progressive supranuclear palsy, variants of multiple system atrophy, Parkinson dementia, and corticobasal degeneration.

CONCLUSION

Today the role of MRI is no longer limited to ruling out underlying causes of cognitive deterioration. MRI can show patterns of atrophy with a predictive value for certain dementias which, although not specific or unique to each disease, can help to confirm diagnostic suspicion or to identify certain processes. For this reason, it is important for radiologists to know the characteristic findings of the most common dementias.

Amyloid PET in neurodegenerative diseases with dementia

Alzheimer's disease (AD) is a neurodegenerative condition characterized by progressive cognitive decline and memory loss, and is the most common form of dementia. Amyloid plaques with neurofibrillary tangles are a neuropathological hallmark of AD that produces synaptic dysfunction and culminates later in neuronal loss. Amyloid PET is a useful, available and non-invasive technique that provides in vivo information about the cortical amyloid burden. In the latest revised criteria for the diagnosis of AD biomarkers were defined and integrated: pathological and diagnostic biomarkers (increased retention on fibrillar amyloid PET or decreased Aβ_1-42 and increased T-Tau or P-Tau in CSF) and neurodegeneration or topographical biomarkers (temporoparietal hypometabolism on ¹⁸F-FDG PET and temporal atrophy on MRI). Recently specific recommendations have been created as a consensus statement on the appropriate use of the imaging biomarkers, including amyloid PET: early-onset cognitive impairment/dementia, atypical forms of AD, mild cognitive impairment with early age of onset, and to differentiate between AD and other neurodegenerative diseases that occur with dementia. Amyloid PET is also contributing to the development of new therapies for AD, as well as in research studies for the study of other neurodegenerative diseases that occur with dementia where the deposition of Aβ amyloid is involved in its pathogenesis. In this paper, we review some general concepts and study the use of amyloid PET in depth and its relationship with neurodegenerative diseases and other diagnostic techniques.

Level of understanding of Alzheimer disease among caregivers and the general population

INTRODUCTION

Understanding of Alzheimer disease is fundamental for early diagnosis and to reduce caregiver burden. The objective of this study is to evaluate the degree of understanding of Alzheimer disease among informal caregivers and different segments of the general population through the Alzheimer's Disease Knowledge Scale.

PATIENTS AND METHODS

We assessed the knowledge of caregivers in different follow-up periods (less than one year, between 1 and 5 years, and over 5 years since diagnosis) and individuals from the general population. Alzheimer's Disease Knowledge Scale scores were grouped into different items: life impact, risk factors, symptoms, diagnosis, treatment, disease progression, and caregiving.

RESULTS

A total of 419 people (215 caregivers and 204 individuals from the general population) were included in the study. No significant differences were found between groups for overall Alzheimer's Disease Knowledge Scale score (19.1 vs. 18.8, P = .9). There is a scarce knowledge of disease risk factors (49.3%) or the care needed (51.2%), while symptoms (78.6%) and course of the disease (77.2%) were the best understood aspects. Older caregiver age was correlated with worse Alzheimer's Disease Knowledge Scale scores overall and for life impact, symptoms, treatment, and disease progression (P < .05). Time since diagnosis improved caregivers' knowledge of Alzheimer disease symptoms (P = .00) and diagnosis (P = .05).

CONCLUSION

Assessing the degree of understanding of Alzheimer disease is essential to the development of health education strategies both in the general population and among caregivers.

Development, equivalence study, and normative data of version B of the Spanish-language Free and Cued Selective Reminding Test

INTRODUCTION

The Free and Cued Selective Reminding Test (FCSRT) is widely used for the assessment of verbal episodic memory, mainly in patients with Alzheimer disease. A Spanish version of the FCSRT and normative data were developed within the NEURONORMA project. Availability of alternative, equivalent versions is useful for following patients up in clinical settings. This study aimed to develop an alternative version of the original FCSRT (version B) and to study its equivalence to the original Spanish test (version A), and its performance in a sample of healthy individuals, in order to develop reference data.

METHODS

We evaluated 232 healthy participants of the NEURONORMA-Plus project, aged between 18 and 90. Thirty-three participants were assessed with both versions using a counterbalanced design.

RESULTS

High intra-class correlation coefficients (between 0.8 and 0.9) were observed in the equivalence study. While no significant differences in performance were observed in total recall scores, free recall scores were significantly lower for version B.

CONCLUSIONS

These preliminary results suggest that the newly developed FCSRT version B is equivalent to version A in the main variables tested. Further studies are necessary to ensure interchangeability between versions. We provide normative data for the new version.

Blood biomarkers in Alzheimer's disease

INTRODUCTION

The early diagnosis of Alzheimer's disease (AD) via the use of biomarkers could facilitate the implementation and monitoring of early therapeutic interventions with the potential capacity to significantly modify the course of the disease.

DEVELOPMENT

Classic cerebrospinal fluid biomarkers and approved structural and functional neuroimaging have a limited clinical application given their invasive nature and/or high cost. The identification of more accessible and less costly biomarkers, such as blood biomarkers, would facilitate application in clinical practice. We present a literature review of the main blood biochemical biomarkers with potential use for diagnosing Alzheimer's disease.

CONCLUSIONS

Blood biomarkers are cost and time effective with regard to cerebrospinal fluid biomarkers. However, the immediate applicability of blood biochemical biomarkers in clinical practice is not very likely. The main limitations come from the difficulties in measuring and standardising thresholds between different laboratories and in failures to replicate results. Among all the molecules studied, apoptosis and neurodegeneration biomarkers and the biomarker panels obtained through omics approaches, such as isolated or combined metabolomics, offer the most promising results.

Validity of a computerized population registry of dementia based on clinical databases

INTRODUCTION

The handling of information through digital media allows innovative approaches for identifying cases of dementia through computerized searches within the clinical databases that include systems for coding diagnoses. The aim of this study was to analyze the validity of a dementia registry in Gipuzkoa based on the administrative and clinical databases existing in the Basque Health Service.

METHODS

This is a descriptive study based on the evaluation of available data sources. First, through review of medical records, the diagnostic validity was evaluated in 2 samples of cases identified and not identified as dementia. The sensitivity, specificity and positive and negative predictive value of the diagnosis of dementia were measured. Subsequently, the cases of living dementia in December 31, 2016 were searched in the entire Gipuzkoa population to collect sociodemographic and clinical variables.

RESULTS

The validation samples included 986 cases and 327 no cases. The calculated sensitivity was 80.2% and the specificity was 99.9%. The negative predictive value was 99.4% and positive value was 95.1%. The cases in Gipuzkoa were 10,551, representing 65% of the cases predicted according to the literature. Antipsychotic medication were taken by a 40% and a 25% of the cases were institutionalized.

CONCLUSIONS

A registry of dementias based on clinical and administrative databases is valid and feasible. Its main contribution is to show the dimension of dementia in the health system.

[Patterns of detection of mild cognitive impairment in nursing]

Mild cognitive impairment (MCI) is characterized by an acquired cognitive loss that places individuals, mainly older adults, in an intermediate stage between normal cognitive functioning and dementia. This impairment has a high risk of progression to dementia and is suitable for screening, which allows more effective early intervention. Nursing professionals, especially community-based primary care nurses, play an important role in the detection and follow-up of MCI and in interventions for this condition. The first step should be to take a thorough history from both the patient and his or her carers, which should assess the changes occurring in the patient's daily, family and social life through functional patterns. In subsequent assessment of cognitive function, brief screening tests can be used such as the Mini Mental State Examination (MMSE) or other similar tests. Special attention should be paid to the presence of affective or depressive symptoms, sensory deficits, polypharmacy, decompensated cardiovascular risk factors, and rapid functional deterioration, given their particular influence on MCI. Finally, various nurse-led, non-pharmacological interventions that are effective in MCI can be recommended, based on cardiovascular risk factor control, physical exercise, and cognitive and psychosocial interventions.

[Mild behavioral impairment: a new concept for the prodromic phases of dementia]

Neuropsychiatric symptoms (NPS) are frequent in dementia. These symptoms are also present in patients with mild cognitive impairment (MCI) and can even constitute the first manifestations of a neurodegenerative process, preceding the development of cognitive symptoms. The presence of NPS is associated with higher rates of conversion to dementia in healthy persons and patients with MCI. Recognizing the importance of NPS, the Alzheimer Association created a working group that has designed the ISTAART criteria for mild behavioral impairment (MBI), including the following areas of assessment: motivation, affect, impulse control, social appropriateness and thoughts/perception. The ISTAART criteria allow identification of NPS to prospectively assess the risk of a person developing dementia. The Mild Behavioral Impairment-Checklist (MBI-C) has subsequently been developed, which allows the MBI construct to be specifically assessed by quantifying the distinct symptoms, thus enhancing the clinical utility of this construct in clinical practice and research.

Report by the Spanish Foundation of the Brain on the social impact of Alzheimer disease and other types of dementia

INTRODUCTION

Knowledge of the socioeconomic impact of dementia-related disorders is essential for appropriate management of healthcare resources and for raising social awareness.

METHODS

We performed a literature review of the published evidence on the epidemiology, morbidity, mortality, associated disability and dependence, and economic impact of dementia and Alzheimer disease (AD) in Spain.

CONCLUSIONS

Most population studies of patients older than 65 report prevalence rates ranging from 4% to 9%. Prevalence of dementia and AD is higher in women for nearly every age group. AD is the most common cause of dementia (50%-70% of all cases). Dementia is associated with increased morbidity, mortality, disability, and dependence, and results in a considerable decrease in quality of life and survival. Around 80% of all patients with dementia are cared for by their families, which cover a mean of 87% of the total economic cost, resulting in considerable economic and health burden on caregivers and loss of quality of life. The economic impact of dementia is huge and difficult to evaluate due to the combination of direct and indirect costs. More comprehensive programmes should be developed and resources dedicated to research, prevention, early diagnosis, multidimensional treatment, and multidisciplinary management of these patients in order to reduce the health, social, and economic burden of dementia.

[Map of Alzheimer's disease and other dementias in Spain. MapEA Project]

INTRODUCTION

In the current context of increased life expectancy and progressive aging of the population a very significant increase in the number of people with cognitive impairment and dementia is expected. Consequently, Spain will face an enormous social and health problem in the next decades. The Mapa de la enfermedad de Alzheimer y otras demencias en España project aims to analyse plans, prevention and early diagnosis activities, process of care and resources available across the 17 Spanish regions for the management of cognitive impairment and dementia in order to identify improvement areas, as well as to provide a list of recommendations.

METHODS

The working group consisted of an Advisory Committee of 5 national experts and a Committee of Experts from each region made up of professionals in the field of Neurology, Geriatrics, Psychiatry, and Primary Care, as well as representatives of Family Associations of People with Alzheimer's and other dementias. The Expert Committee of each region held meetings in which the current situation of care was reviewed.

RESULTS

Plans available in Spain for dementia management are mostly obsolete or have not been implemented. Prevention and early detection activities are generally not carried out. There is great variability of care process that patients must follow for the diagnosis, treatment, and follow-up of the disease, and not all diagnostic test are available in different regions. In general, resources are considered scarce and unknown.

CONCLUSIONS

The Mapa de la enfermedad de Alzheimer y otras demencias en España study has been able to detect the main points that require changing n the management, organisation, and coordination of resources, such as information and training of the personnel involved. Furthermore, the study has revealed that, in Spain, the necessary conditions are in place in Spain, such as the availability and capacity of professionals involved, as well as there being the potential diagnostic and health care resources to address this room for improvement through the approval and development of a National Alzheimer's Plan, supported by a deep and truthful political commitment, which will be the ideal framework for the development of these possibilities.

[Diagnostic criteria. Benefits of early diagnosis]

Almost 36 million persons live with dementia worldwide. This figure is set to double by 2030, with 66 million patients, and by 2050 there will be 116 million affected persons. Dementia has an economic impact on individuals and health services and affects the global economy. It is important to evaluate costs to plan social services and healthcare and to provide information on the cost-effectiveness of treatments. The economic cost of dementia was around 604 billion dollars in 2010 and estimates are obviously set to rise.