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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. METHODS: A cross-sectional study was conducted with sociodemographic and clinical data of all PT applicants from 1995-2023. Reasons for seeking PT were assessed using a modified questionnaire. In addition, anxiety, and depressive symptoms before and after PT were evaluated with Beck's instruments; cognitive impairment (CI) was assessed with the Mini-Mental State Examination (MMSE) and molecular results. RESULTS: 214 people applied for PT (2.1% of the at-risk population identified in our center); 63% were women (mean age of 37.11 years). 204 (95.3%) were accepted and 190 received results. 70% indicated that the main reason for applying for PT was to inform their offspring about the risk of inheriting HD. Significant differences were observed in the reasons for seeking PT by age group. Although some subjects received treatment, Beck's instrument scores did not indicate special attention or pharmacological treatment. The MMSE showed probable CI in 20 subjects. Of those who received results, 37% were carriers of a full penetrance allele. CONCLUSION: Our center has the only formal PT program for HD in Mexico. The reasons for seeking PT are varied and age-related. Although PT is offered to all subjects at risk for HD, uptake remains low.
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Doença de Huntington , Humanos , Doença de Huntington/genética , Doença de Huntington/diagnóstico , Doença de Huntington/epidemiologia , Feminino , Masculino , Adulto , México/epidemiologia , Estudos Transversais , Pessoa de Meia-Idade , Testes Genéticos , Adulto JovemRESUMO
Objectives: To report the first Mexican case with two novel AARS2 mutations causing primary ovarian failure, uterus infantilis, 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. Neuroimaging studies revealed frontal leukoencephalopathy with hypometabolism at the fronto-cerebellar cortex and caudate nucleus. Uterus infantilis was detected on ultrasound study. Clinical exome sequencing identified two novel variants, NM_020745:c.2864G>A (p.W955*) and NM_020745:c.1036C>A (p.P346T, p.P346Wfs*18), in AARS2. Histopathological and biochemical studies on muscle biopsy revealed mitochondrial disorder with cytochrome C oxidase (COX) deficiency. Conclusions: Several adult-onset cases of leukoencephalopathy and ovarian failure associated with AARS2 variants have been reported. To our best knowledge, none of them showed uterus infantilis. Here we enlarge the genetic and phenotypic spectrum of AARS2-related dementia with leukoencephalopathy and ovarian failure and contribute with detailed clinical, clinometric, neuroimaging, and molecular studies to disease and novel molecular variants characterization.
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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 (n = 6), aMCI subjects without anosognosia (n = 12), AD subjects with anosognosia (n = 6), and AD subjects without anosognosia (n = 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. Furthermore, we identified that the mean hippocampal gray matter density of aMCI subjects with anosognosia was not statistically different than that of AD subjects. The groups of aMCI and AD subjects with anosognosia also displayed a lower GMD in the bilateral cingulum cortex compared to subjects without anosognosia, but these differences were not statistically significant. No statistically significant differences were found in the fractional anisotropy or mean diffusivity of the hippocampus or cingulum between subjects with and without anosognosia in aMCI or AD groups. While these findings are derived from a small population of subjects and are in need of replication, they suggest that anosognosia in aMCI might be a useful clinical marker to suspect brain changes associated with AD neuropathology.
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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). We compared the performance of 21 young adults (YA) and 27 older adults (OA) in Spain, and 34 YA and 36 OA in Mexico. Recall was analyzed using a mixed-model ANOVA including subtest scores as dependent variables, age group as a fixed-factor independent variable, and recall subtest as a three-level repeated-measure independent variable. The rest of the associative memory domains were analyzed through t-tests comparing the performance of YA and OA. RESULTS: In Spain, we found significant effects for age group and recall subtest, with large effect sizes. The recognition subtests (Face Recognition, Name Recognition) displayed ceiling effects in both groups. The new subtests displayed medium-to-large effect sizes when comparing age groups. In Mexico, these results were replicated, additionally controlling for education. In both studies, recall performance improved after repeated exposures and it was sustained after 30 minutes in YA and OA. CONCLUSIONS: We document, in two different countries, a clear aging pattern on the extended FNAME: regardless of education, OA remember fewer stimuli than YA through recall subtests. The new subtests provide evidence on associative memory changes in aging beyond recall.
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Memória , Nomes , Idoso , Humanos , Rememoração Mental , México , Testes Neuropsicológicos , EspanhaRESUMO
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). METHODS: The study protocol consists of a cognitive assessment instrument for the target subject and an informant questionnaire. All cognitive measures were selected and adapted by a team of experts from different ongoing studies following criteria to warrant reliable and comparable cognitive instruments. The informant questionnaire is from the 10/66 Dementia Study in Mexico. RESULTS: A total of 2,265 subjects aged 55-104 years participated, representing a 70% response rate. Validity analyses showed the adequacy of the content validity, proper quality-control procedures that sustained data integrity, high reliability, and internal structure. CONCLUSIONS: The Mex-Cog study provides in-depth cognitive data that enhances the study of cognitive aging in two ways. First, linking to MHAS longitudinal data on cognition, health, genetics, biomarkers, economic resources, health care, family arrangements, and psychosocial factors expands the scope of information on cognitive impairment and dementia among Mexican adults. Second, harmonization with other similar studies around the globe promotes cross-national studies on cognition with comparable data. Mex-Cog data is publicly available at no cost to researchers.
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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. However, there is no information concerning the behavior and participation of AHR in the human aging brain or in Alzheimer's disease (AD). We evaluated the expression of AHR in human hippocampal post-mortem tissue and its association with reactive astrocytes by immunohistochemistry. Besides this, we analyzed through ELISA the AHR levels in blood serum from young and elder participants, and from AD patients. The levels of AHR and glial fibrillar acid protein were higher in elder than in young post-mortem brain samples. AHR was localized mainly in the cytosol of astrocytes and displayed a pattern that resembles extracellular vesicles; this latter feature was more conspicuous in AD subjects. We found higher serum levels of AHR in AD patients than in the other participants. These results suggest that AHR participates in the aging process, and probably in the development of neurodegenerative diseases like AD.
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Doença de Alzheimer/metabolismo , Astrócitos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/análise , Fatores de Transcrição Hélice-Alça-Hélice Básicos/sangue , Hipocampo/metabolismo , Receptores de Hidrocarboneto Arílico/análise , Receptores de Hidrocarboneto Arílico/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Animais , Ensaio de Imunoadsorção Enzimática , Vesículas Extracelulares/metabolismo , Feminino , Proteína Glial Fibrilar Ácida/análise , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Adulto JovemRESUMO
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. The association between current work status and the presence of an MDE was estimated using binary logistic regression models with country-level fixed effects, and interaction terms between the country and work status. Results showed the odds of presenting an MDE were lower for older adults who were retired with a pension than for those who were currently working, although this protective association was observed only for men in China (OR=0.23; CI 95%:0.08-0.70) and Ghana (OR=0.25; CI 95%:0.07-0.95) and for women in India (OR=0.05; CI 95%:0.01-0.51) and South Africa (OR=0.19; CI 95%:0.04-0.97). For women, being a homemaker also showed a protective association in South Africa (OR=0.09; CI95%:0.01-0.66) and Mexico (OR=0.32; CI95%:0.14-0.76). In the case of being retired without a pension, no significant association was found in any country. The previous indicates that retirement with pension has a protective association with MDE only for men in China and Ghana and women in India and South Africa. The heterogeneity of this association reflects cultural and socioeconomic differences between the analysed countries.
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BACKGROUND: Recent epidemiological research has shown that exposure to fine particulate pollution (PM2.5) 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 PM2.5 and cognitive function in a nationally representative sample of older Mexican adults and the associated effect modifiers. METHODS: Data for this study were taken from the National Survey of Health and Nutrition in Mexico carried out in 2012. A total of 7986 older adults composed the analytical sample. Cognitive function was assessed using two tests: semantic verbal fluency and three-word memory. The annual concentration of PM2.5 was calculated using satellite data. Association between exposure to PM2.5 and cognitive function was estimated using two-level logistic and linear regression models. RESULTS: In adjusted multilevel regression models, each 10⯵g/m3 increase in ambient PM2.5 raised the odds of a poorer cognitive function using the three-word memory test (ORâ¯=â¯1.37, 95% CI: 1.08, 1.74), and reduced the number of valid animal named in the verbal fluency test (ßâ¯=â¯-0.72, 95% CI: -1.05, -0.40). Stratified analyses did not yield any significant modification effects of age, sex, indoor pollution, urban/rural dwelling, education, smoking and other factors. CONCLUSIONS: This study supports an association between exposure to PM2.5 concentrations and cognitive function in older adults. This is particularly relevant to low- and middle-income countries, which are marked by a rapid growth of their aging population and high levels of air pollution.
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Poluentes Atmosféricos/análise , Poluição do Ar , Cognição/fisiologia , Exposição Ambiental , Material Particulado/análise , Idoso , Poluição do Ar/análise , Poluição do Ar/estatística & dados numéricos , Exposição Ambiental/análise , Exposição Ambiental/estatística & dados numéricos , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-IdadeRESUMO
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. In the present article, we present the case of an artist who, after resection of a central neurocytoma that affected the right thalamo-parietal connections, suffered an impairment of the ability to create perspective in his paintings and involuntary omission of only shapes in the left side of his paintings, although colors and contours were preserved.
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Neoplasias Encefálicas/cirurgia , Percepção de Profundidade/fisiologia , Percepção de Forma/fisiologia , Neurocitoma/cirurgia , Pinturas , Transtornos da Percepção/fisiopatologia , Complicações Pós-Operatórias/fisiopatologia , Adulto , Humanos , Imageamento por Ressonância Magnética , Masculino , Procedimentos Neurocirúrgicos , Transtornos da Percepção/diagnóstico por imagem , Complicações Pós-Operatórias/diagnóstico por imagemRESUMO
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. Cognitive function was evaluated by a standardized test, social support was evaluated through latent class analysis (LCA). The LCA was run to obtain three subgroups of different Social Support Levels (SSL): low, medium, and high. Logistic regression models, stratified by age, were performed to analyze the association between SSL and cognitive function. RESULTS: For respondents ages 71-80 y/o, there was an inverse relationship with cognitive impairment for those with medium (OR 0.23, p=0.020) and high (OR 0.07, p=0.000) SSL in comparison with low SSL. While social support helped to improve cognitive function in older adults aged 71-80, this same association was not observed in adults of other ages. Those younger than 70 y/o may not need such a strong support network as a result of being more self-sufficient. After 80, social networks were not enough to help diminish the negative impact of cognitive impairment. CONCLUSION: Social support could improve the cognitive function of adults ages 71 and 80; suggesting there could be a window of opportunity to improve cognitive functioning for this group.