Structural inequality linked to brain volume and network dynamics in aging and dementia across the Americas.

Structural inequality, the uneven distribution of resources and opportunities, influences health outcomes. However, the biological embedding of structural inequality in aging and dementia, especially among underrepresented populations, is unclear. We examined the association between structural inequality (country-level and state-level Gini indices) and brain volume and connectivity in 2,135 healthy controls, and individuals with Alzheimer's disease and frontotemporal lobe degeneration from Latin America and the United States.

Brain clocks capture diversity and disparities in aging and dementia across geographically diverse populations.

Brain clocks, which quantify discrepancies between brain age and chronological age, hold promise for understanding brain health and disease. However, the impact of diversity (including geographical, socioeconomic, sociodemographic, sex and neurodegeneration) on the brain-age gap is unknown. We analyzed datasets from 5,306 participants across 15 countries (7 Latin American and Caribbean countries (LAC) and 8 non-LAC countries).

Educational disparities in brain health and dementia across Latin America and the United States.

Background: Education influences brain health and dementia. However, its impact across regions, specifically Latin America (LA) and the United States (US), is unknown.

Methods: A total of 1412 participants comprising controls, patients with Alzheimer's disease (AD), and frontotemporal lobar degeneration (FTLD) from LA and the US were included.

Brain clocks capture diversity and disparity in aging and dementia.

Brain clocks, which quantify discrepancies between brain age and chronological age, hold promise for understanding brain health and disease. However, the impact of multimodal diversity (geographical, socioeconomic, sociodemographic, sex, neurodegeneration) on the brain age gap (BAG) is unknown. Here, we analyzed datasets from 5,306 participants across 15 countries (7 Latin American countries -LAC, 8 non-LAC).

Presymptomatic Testing for Huntington's Disease in Mexico: 28 Years of Experience.

Introduction: Huntington's disease (HD) is a genetic neurodegenerative disorder with dominant inheritance. Our center in Mexico City has offered presymptomatic testing (PT) since 1995.

Objective: To describe the main clinical and demographic characteristics of at-risk HD individuals who applied to the PT program, the reasons for seeking it, and the molecular results.

Uterus a novel phenotype associated with new genetic variants. A case report.

Objectives: To report the first Mexican case with two novel mutations causing primary ovarian failure, uterus , and early-onset dementia secondary to leukoencephalopathy.

Methods: Detailed clinical, clinimetric, neuroimaging features, muscle biopsy with biochemical assays of the main oxidative phosphorylation complexes activities, and molecular studies were performed on samples from a Mexican female.

Results: We present a 41-year-old female patient with learning difficulties since childhood and primary amenorrhea who developed severe cognitive, motor, and behavioral impairment in early adulthood.

Classification of Alzheimer's disease and frontotemporal dementia using routine clinical and cognitive measures across multicentric underrepresented samples: A cross sectional observational study.

Background: Global brain health initiatives call for improving methods for the diagnosis of Alzheimer's disease (AD) and frontotemporal dementia (FTD) in underrepresented populations. However, diagnostic procedures in upper-middle-income countries (UMICs) and lower-middle income countries (LMICs), such as Latin American countries (LAC), face multiple challenges. These include the heterogeneity in diagnostic methods, lack of clinical harmonisation, and limited access to biomarkers.

Extended FNAME performance is preserved in subjective cognitive decline but highly affected in amnestic mild cognitive impairment.

Objective: The cognitive characterization of Alzheimer's disease risk states, such as amnestic mild cognitive impairment (aMCI) and subjective cognitive decline (SCD), is fundamental for timely diagnosis and interventions. The Face Name Associative Memory Exam (FNAME) is sensitive to early Alzheimer's disease brain changes, and an extended version captures a fuller range of associative memory abilities. We aimed to assess group effects in the extended FNAME in older adults with SCD, aMCI, and older adult controls (CON).

Anosognosia in Amnestic Mild Cognitive Impairment Is Related to Diminished Hippocampal Volume Comparable to Alzheimer's Disease Dementia: Preliminary MRI Findings.

Although the presence of anosognosia in amnestic mild cognitive impairment (aMCI) may be predictive of conversion to Alzheimer's disease (AD), little is known about its neural correlates in AD and aMCI. Four different groups were compared using volumetric and diffusion magnetic resonance imaging metrics in regions of interest (hippocampus and cingulum cortex gray matter, cingulum bundle white matter): aMCI subjects with anosognosia ( = 6), aMCI subjects without anosognosia ( = 12), AD subjects with anosognosia ( = 6), and AD subjects without anosognosia ( = 9). aMCI subjects with anosognosia displayed a significantly lower gray matter density (GMD) in the bilateral hippocampus than aMCI subjects without anosognosia, which was accounted for by bilateral hippocampal differences.

Worse associative memory recall in healthy older adults compared to young ones, a face-name study in Spain and Mexico.

Introduction: The Face Name Associative Memory Exam (FNAME) is sensitive to associative memory changes early in the Alzheimer's disease spectrum, but little is known about how healthy aging affects FNAME performance. We aimed to assess aging effects on an extended version of the test, which captures further associative memory abilities beyond the recall and recognition domains measured in the original version.

Method: We adapted FNAME versions in Spain and Mexico, adding new subtests (Spontaneous Name Recall, Face-Name Matching).

The Multi-Partner Consortium to Expand Dementia Research in Latin America (ReDLat): Driving Multicentric Research and Implementation Science.

Dementia is becoming increasingly prevalent in Latin America, contrasting with stable or declining rates in North America and Europe. This scenario places unprecedented clinical, social, and economic burden upon patients, families, and health systems. The challenges prove particularly pressing for conditions with highly specific diagnostic and management demands, such as frontotemporal dementia.

Serum Repressor Element-1 Silencing Transcription Factor Levels in Alzheimer's Patients from a National Institute of Health in Mexico City, Elderly and Young Controls.

Background: Decreased levels of repressor element-1 silencing transcription (REST) factor in the brain, plasma, and neuronderived exosomes are associated with Alzheimer's disease (AD).

Objective: The objective of the study was to test the viability of serum REST as a possible blood-based biomarker for AD, comparing serum REST levels in AD patients from a National Institute of Health in Mexico City (with different levels of severity and comorbidities), with elderly controls (EC) and young controls (YC).

Methods: We used an enzyme-linked immunosorbent assay to determine serum REST levels in AD patients (n = 28), EC (n = 19), and YC (n = 24); the AD patients were classified by dementia severity and comorbidities (depression and microangiopathy) using clinimetric tests and magnetic resonance imaging.

The Mexican Cognitive Aging Ancillary Study (Mex-Cog): Study Design and Methods.

Objective: Describe the protocol sample and instruments of the Cognitive Aging Ancillary Study in Mexico (Mex-Cog). The study performs an in-depth cognitive assessment in a subsample of older adults of the ongoing Mexican Health and Aging Study (MHAS). The Mex-Cog is part of the Harmonized Cognitive Assessment Protocol (HCAP) design to facilitate cross-national comparisons of the prevalence and trends of dementia in aging populations around the world, funded by the National Institute on Aging (NIA).

Aryl Hydrocarbon Receptor in Post-Mortem Hippocampus and in Serum from Young, Elder, and Alzheimer's Patients.

One of the characteristics of the cerebral aging process is the presence of chronic inflammation through glial cells, which is particularly significant in neurodegeneration. On the other hand, it has been demonstrated that the aryl hydrocarbon receptor (AHR) participates in the inflammatory response. Currently, evidence in animal models shows that the hallmarks of aging are associated with changes in the AHR levels.

Autonomic Dysfunction in α-Synucleinopathies.

The α-synucleinopathies are a group of neurodegenerative diseases characterized by abnormal accumulation of insoluble α-synuclein in neurons and glial cells, comprising Parkinson's disease (PD), dementia with Lewy bodies (DLB) and multiple system atrophy (MSA). Although varying in prevalence, symptom patterns, and severity among disorders, all α-synucleinopathies have in common autonomic nervous system dysfunctions, which reduce quality of life. Frequent symptoms among α-synucleinopathies include constipation, urinary and sexual dysfunction, and cardiovascular autonomic symptoms such as orthostatic hypotension, supine hypertension, and reduced heart rate variability.

Work status, retirement, and depression in older adults: An analysis of six countries based on the Study on Global Ageing and Adult Health (SAGE).

The aim of the present study was to analyse the association between the occurrence of a major depressive episode among older adults and work status in low- and medium-income countries. A cross-sectional study was conducted with people 60 years of age and older from the six countries (Mexico, India, China, Russian Federation, Ghana and South Africa) included in the Study on Global Ageing and Adult Health (SAGE) and who participated in its first wave (2009-2010). The occurrence of a major depressive episode (MDE) over the previous 12 months was determined based on an adaptation of the ICD-10 diagnostic criteria.

Exposure to ambient PM concentrations and cognitive function among older Mexican adults.

Background: Recent epidemiological research has shown that exposure to fine particulate pollution (PM) is associated with a reduction in cognitive function in older adults. However, primary evidence comes from high-income countries, and no specific studies have been conducted in low and middle-income countries where higher air pollution levels exist.

Objectives: To estimate the association between the exposure to PM and cognitive function in a nationally representative sample of older Mexican adults and the associated effect modifiers.

The painter from Sinaloa: artistic analysis of a case of spatial agnosia and neglect of visual shapes.

Paintings produced spontaneously by patients with neurological lesions represent a fascinating opportunity to analyze some aspects of the underlying disease and involved brain mechanisms. Many cases of artists who have suffered spatial neglect following a neurological disease have been reported in the literature. However, only a few studies evaluating the different subtypes of graphic neglect and aspects related to the construction of perspective (three dimensionality) in works of art have been published.

Effective connectivity during successful and unsuccessful recollection in young and old adults.

Aging effects on regional brain activation have been studied extensively to explain the gradual recollection failure that occurs with advancing age. However, little is known about the consequence of aging on the interaction among brain regions that support recollection. The purpose of this study was to examine effective connectivity at encoding and retrieval during successful and unsuccessful recollection in young and old adults.

The association between social support and cognitive function in Mexican adults aged 50 and older.

Unlabelled: Social support networks are crucial for the health of older adults; however, personal characteristics and time of life may diminish the protective effect of social support.

Objective: to determine if the presence of social support networks were associated with cognitive impairment among Mexican adults aged 50 or older and if this relationship was different based on age.

Method: This study analyzed data from the National Representation Survey performed in Mexico, Study on Global Ageing (SAGE) wave 1.

Factors associated with cognitive function in older adults in Mexico.

Background: As populations age, cognitive decline and dementia pose significant burdens for societies and health care systems, including low- and middle-income countries such as Mexico. Minor age-related declines in cognitive function appear to represent a stable but heterogeneous phase in the continuum between normal cognitive ageing and dementia. Loss of cognitive function has impacts at societal and individual levels and understanding the risk factors can help provide a framework for health policies and interventions to target at-risk groups.

Brain activity during source memory retrieval in young, middle-aged and old adults.

We investigated neurofunctional changes associated with source memory decline across the adult life span using functional magnetic resonance imaging (fMRI). Young, middle-aged and old adults carried out a natural/artificial judgment of images of common objects that were randomly presented in one of the quadrants of the screen. At retrieval, the images were displayed at the center of the screen and the participants judged whether each image was new or old and, if old, they indicated in which quadrant of the screen the image had originally been presented.

fMRI subsequent source memory effects in young, middle-aged and old adults.

The ability to remember the spatial context in which our experiences occur declines linearly across the adult lifespan. However, little is known about whether this source memory decline is associated with neural activity changes. In the present study, functional magnetic resonance imaging (fMRI) scans were recorded in young, middle-aged and old adults to investigate brain activity variations across the adult lifespan during encoding of subsequent spatial source memory retrieval.