Browsing by Author "Ibañez, Agustin"
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Publication Biomarkers for dementia in Latin American countries: Gaps andopportunities(2023) Parra, Mario A.; Orellana, Paulina; León, Tomas; Victoria, Cabello G.; Henriquez, Fernando; Gomez, Rodrigo; Avalos, Constanza; Damian, Andres; Slachevsky Chonchol, Andrea; Ibañez, Agustin; Zetterberg, Henrik; Tijms, Betty M.; Yokoyama, Jennifer S.; Piña-Escudero, Stefanie D.; Cochran, Nicholas; Matallana, Diana L.; Acosta, Daisy; Allegri, Ricardo; Arias-Suáres, Bianca P.; Barra, Bernardo; Behrens, María Isabel; Brucki, Sonia M.D.; Busatto, Geraldo; Caramelli, Paulo; Castro-Suarez, Sheila; Contreras, Valeria; Custodio, Nilton; Dansilio, Sergio; De la Cruz-Puebla, Myriam; Cruz de Souza, Leonado; Díaz, Monica M.; Duque, Lissette; Farias, Gonzalo A.; Ferreira, Sergio T.; Magrath Guimet, Nahuel; Kmaid, Ana; Lira, David; Lopera, Francisco; Mar Meza, Beatriz; Miotto, Eliane C.Limited knowledge on dementia biomarkers in Latin American and Caribbean (LAC)countries remains a serious barrier. Here, we reported a survey to explore the ongo-ing work, needs, interests, potential barriers, and opportunities for future studiesrelated to biomarkers. The results show that neuroimaging is the most used biomarker(73%), followed by genetic studies (40%), peripheral fluids biomarkers (31%), and cere-brospinal fluid biomarkers (29%). Regarding barriers in LAC, lack of funding appears toundermine the implementation of biomarkers in clinical or research settings, followedby insufficient infrastructure and training. The survey revealed that despite the abovebarriers, the region holds a great potential to advance dementia biomarkers research.Considering the unique contributions that LAC could make to this growing field,we highlight the urgent need to expand biomarker research. These insights allowedus to propose an action plan that addresses the recommendations for a biomarkerframework recently proposed by regional experts.Publication Dementia prevention requires moving beyond individual choice: the costs of effort and time intersect with social determinants of health(2025) Migeot, Joaquín; Araya, Daniel; Montecinos, Matias; Baez, Sandra; Behrens, Maria Isabel; Castaner, Olga; Cruzat, Josephine; Delgado, Carolina; De Jong- Bambagioni, David; Duran, Claudia; Durón, Dafne; Evans, Tavia; Gonzalez, Raul; Gutiérrez, Myriam; Hayden, Katheen; Hernandez, Hernan; Ibañez, Agustin; Legaz, Agustina; Miller, Johnny; Ma iulskyt, Sonata; Putthinun, Pongpat; Santamaría, Hernando; Slachevsky Chonchol, Andrea; Trépel, DominicSocial determinants of health strongly influence modifiable risk factors for dementia, yet prevention frameworks list only individual-level behaviours and conditions, overlooking the impact of social and environmental factors on the risk of dementia. In this perspective, we introduce the concept of non-monetary costs as a central mechanism through which social determinants shape modifiable risk factors by influencing individuals' ability to adopt healthy behaviours. Drawing from economic theory, we define non-monetary costs as the time and metabolic cost, perceived by individuals as physical and cognitive effort, required to engage in healthy behaviours. Under adverse social determinants of health, individuals effectively lack choice, as the non-monetary costs required to engage in healthy behaviours become prohibitively high. We propose a framework that links social determinants of health adversity to increased dementia risk through non-monetary costs. We apply this framework to each of the fourteen modifiable risk factors for dementia identified by the Lancet Commission, demonstrating how these costs systematically elevate risk in populations facing social adversity. Finally, we explore the implications of incorporating non-monetary cost assessments across research, interventions, clinical care, and public policy. We propose that quantifying and addressing these costs is essential for designing equitable, scalable, and contextually grounded strategies for dementia prevention across socially diverse populations.Publication Educational disparities in brain health and dementia across Latin America and the United States(2024) Gonzalez, Raul; Legaz, Agustina; Moguilner, Sebastián; Cruzat, Josephine; Hernández, Hernán; Baez, Sandra; Cocchi, Rafael; Coronel, Carlos; Medel,Vicente; Tagliazuchi, Enzo; Migeot, Joaquín; Ochoa, Carolina; Maito, Marcelo; Reyes, Pablo; Santamaria, Hernando; Godoy, Maria; Javande, Shireen; García, Adolfo; Matallana, Diana; Avila, José; Slachevsky Chonchol, Andrea; Behrens, María; Custodio, Nilton; Cardona, Juan; Brusco, Ignacio; Bruno, Martín; Sosa, Ana; Pina, Stefanie; Takada, Leonel; França, Elisa; Valcour, Victor; Possin, Katherine; De Oliveira, Maira; Lopera, Francisco; Lawlor, Brian; Hu, Kun; Miller, Bruce; Yokoyama, Jennifer; Gonzalez, Cecilia; Ibañez, AgustinBackground: 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. We studied the association of education with brain volume and functional connectivity while controlling for imaging quality and variability, age, sex, total intracranial volume (TIV), and recording type. Results: Education influenced brain measures, explaining 24%-98% of the geographical differences. The educational disparities between LA and the US were associated with gray matter volume and connectivity variations, especially in LA and AD patients. Education emerged as a critical factor in classifying aging and dementia across regions. Discussion: The results underscore the impact of education on brain structure and function in LA, highlighting the importance of incorporating educational factors into diagnosing, care, and prevention, and emphasizing the need for global diversity in research. Highlights: Lower education was linked to reduced brain volume and connectivity in healthy controls (HCs), Alzheimer's disease (AD), and frontotemporal lobar degeneration (FTLD). Latin American cohorts have lower educational levels compared to the those in the United States. Educational disparities majorly drive brain health differences between regions. Educational differences were significant in both conditions, but more in AD than FTLD. Education stands as a critical factor in classifying aging and dementia across regions.Publication Qualitative and quantitative educational disparities and brain signatures in healthy aging and dementia across global settings(2025) Gonzalez, Raul; Cruzat, Josephine; Hernández, Hernán; Migeot, Joaquín; Legaz, Agustina; Santamaria, Hernando; Fittipaldi, Sol; Maito, Marcelo; Medel, Vicente; Tagliazucchi, Enzo; Barttfeld, Pablo; Franco-O'Byrne, Daniel; Castro, Ana; Borquez, Patricio; Avila, José; Behrens, Maria Isabel; Custodio, Nilton; Farombi, Temitope; García, Adolfo; Garcia, Indira; Godoy, Maria; Gonzalez, Cecilia; Hu, Kun; Lawlor, Brian; Matallana, Diana; Miller, Bruce; Okada, Maira; Pina, Stefanie; França, Elisa de Paula; Reyes, Pablo; Slachevsky Chonchol, Andrea; Takada, Leonel; Yener, Görsev; Coronel, Carlos; Ibañez, AgustinBackground: While education is crucial for brain health, evidence mainly relies on individual measures of years of education (YoE), neglecting education quality (EQ). The effect of YoE and EQ on aging and dementia has not been compared. Methods: We conducted a cross-sectional assessment of the effect of EQ and YoE on brain health in 7533 subjects from 20 countries, including healthy controls (HCs), Alzheimer's disease (AD), and frontotemporal lobar degeneration (FTLD). EQ was based on country-level quality indicators provided by the programme for international student assessment (PISA). After applying neuroimage harmonization, we examined its effect, along with YoE, on gray matter volume and functional connectivity. Regression models were adjusted for age, sex, and cognition, controlling for multiple comparisons. The influence of image quality was assessed through sensitivity analysis. Data collection was conducted between June 1 and October 30, 2024. Findings: Less EQ and YoE were associated with brain alterations across groups. However, EQ had a stronger influence, mainly targeting the critical areas of each condition. At the whole-brain level, EQ influenced volume (HCs: Δmean = 2·0 [1·9-2·0] × 10-2, p < 10-5; AD: Δmean = 0·1 [-0·0 to 0·3] × 10-2, p = 0·18; FTLD: Δmean = 3·5 [3·0-4·0] × 10-2, p < 10-5; all with 95% confidence intervals) and networks (HCs: Δmean = 13·5 [13·2-13·7] × 10-2, p < 10-5; AD: Δmean = 5·9 [5·2-6·7] × 10-2, p < 10-5; FTLD: Δmean = 13·2 [11·2-13·7] × 10-2, p < 10-5) 1·3 to 7·0 times more than YoE. These effects remain robust despite variations in income and socioeconomic factors at country and individual levels. Interpretation: The results support the need to incorporate education quality into studying and improving brain health, underscoring the importance of country-level measures. Funding: Multi-partner consortium to expand dementia research in Latin America (ReDLat).Publication Social exposome and brain health outcomes of dementia across Latin America(2025) Migeot, Joaquin; Pina, Stefanie; Hernandez, Hernan; Gonzalez, Raul; Legaz, Agustina; Fittipaldi, Sol; Resende, Elisa de Paula França; Duran, Claudia; Avila, Jose; Behrens, Maria Isabel; Bruno, Martin; Cardona, Juan; Custodio, Nilton; García, Adolfo; Godoy, Maria; Hu, Kun; Lanata, Serggio; Lawlor, Brian; Lopera, Francisco; Maito, Marcelo; Matallana, Diana; Miller, Bruce; Miranda, J Jaime; Okada, Maira; Reyes, Pablo; Santamaria, Hernando; Slachevsky Chonchol, Andrea; Sosa, Ana; Takada, Leonel; Torres, Jacqueline; Vanneste, Sven; Valcour, Victor; Wen, Olivia; Yokoyama, Jennifer; Possin, Katherine; Ibañez, AgustinA multidimensional social exposome (MSE)-the combined lifespan measures of education, food insecurity, financial status, access to healthcare, childhood experiences, and more-may shape dementia risk and brain health over the lifespan, particularly in underserved regions like Latin America. However, the MSE effects on brain health and dementia are unknown. We evaluated 2211 individuals (controls, Alzheimer's disease, and frontotemporal lobar degeneration) from a non-representative sample across six Latin American countries. Adverse exposomes associate with poorer cognition in healthy aging. In dementia, more complex exposomes correlate with lower cognitive and functional performance, higher neuropsychiatric symptoms, and brain structural and connectivity alterations in frontal-temporal-limbic and cerebellar regions. Food insecurity, financial resources, subjective socioeconomic status, and access to healthcare emerge as critical predictors. Cumulative exposome measures surpass isolated factors in predicting clinical-cognitive profiles. Multiple sensitivity analyses confirm our results. Findings highlight the need for personalized approaches integrating MSE across the lifespan, emphasizing prevention and interventions targeting social disparities.Item Towards affordable biomarkers of frontotemporal dementia: A classification study via network's information sharing(Nature Publishing Group, 2017) Dottori, Martin; Sedeño, Lucas; Martorell, Miguel; Alifano, Florencia; Hesse, Eugenia; Mikulan, Ezequiel; García, Adolfo; Ruiz-Tagle, Amparo; Lillo, Patricia; Slachevsky, Andrea; Serrano, Cecilia; Fraiman, Daniel; Ibañez, AgustinDeveloping effective and affordable biomarkers for dementias is critical given the difficulty to achieve early diagnosis. In this sense, electroencephalographic (EEG) methods offer promising alternatives due to their low cost, portability, and growing robustness. Here, we relied on EEG signals and a novel information-sharing method to study resting-state connectivity in patients with behavioral variant frontotemporal dementia (bvFTD) and controls. To evaluate the specificity of our results, we also tested Alzheimer’s disease (AD) patients. The classification power of the ensuing connectivity patterns was evaluated through a supervised classification algorithm (support vector machine). In addition, we compared the classification power yielded by (i) functional connectivity, (ii) relevant neuropsychological tests, and (iii) a combination of both. BvFTD patients exhibited a specific pattern of hypoconnectivity in mid-range frontotemporal links, which showed no alterations in AD patients. These functional connectivity alterations in bvFTD were replicated with a low-density EEG setting (20 electrodes). Moreover, while neuropsychological tests yielded acceptable discrimination between bvFTD and controls, the addition of connectivity results improved classification power. Finally, classification between bvFTD and AD patients was better when based on connectivity than on neuropsychological measures. Taken together, such findings underscore the relevance of EEG measures as potential biomarker signatures for clinical settings.Item Using game authoring platforms to develop screen-based simulated functional assessments in persons with executive dysfunction following traumatic brain injury(Elsevier, 2017) Martínez, David; Núñez, Javier; del Blanco, Ángel; Ruiz-Tagle, Amparo; Velásquez, Juan; Gomez, Mariela; Blesius, Carl; Ibañez, Agustin; Fernández, Baltasar; Slachevsky, AndreaThe assessment of functional status is a critical component of clinical neuropsychological evaluations used for both diagnostic and therapeutic purposes in patients with cognitive brain disorders. There are, however, no widely adopted neuropsychological tests that are both ecologically valid and easily administered in daily clinical practice. This discrepancy is a roadblock to the widespread adoption of functional assessments. In this paper, we propose a novel approach using a serious game authoring platform (eAdventure) for creating screen-based simulated functional assessments. We created a naturalistic functional task that consisted of preparing a cup of tea (SBS-COT) and applied the assessment in a convenience sample of eight dyads of therapists/patients with mild executive dysfunction after traumatic brain injury. We had three main aims. First, we performed a comprehensive review of executive function assessment in activities of daily living. Second, we were interested in measuring the feasibility of this technology with respect to staffing, economic and technical requirements. Third, a serious game was administered to patients to study the feasibility of this technology in the clinical context (pre-screening test). In addition, quantitative (Technology Acceptance Model (TAM) questionnaires) and qualitative (semistructured interviews) evaluations were applied to obtain user input. Our results suggest that the staffing, economic and technical requirements of the SBS-COT are feasible. The outcomes of the pre-screening test provide evidence that this technology is useful in the functional assessment of patients with executive dysfunction. In relation to subjective data, the TAM questionnaire showed good user acceptability from a professional perspective. Interview analyses with professionals and patients showed positive experiences related to the use of the SBS-COT. Our work indicates that the use of these types of authoring platforms could have positive long-term implications for neuropsychological research, opening the door to more reproducible, cooperative and efficient research by allowing the facilitated production, reuse and sharing of neuropsychological assessment tools.Publication White matter hyperintensities and their impact in brain structure and function in alzheimer's disease and behavioral variant frontotemporal dementia across Latin America and the United States: a cross-sectional study(2025) Altschuler, Florencia; Canziani, Verónica; Fraile, Matías; Gonzalez, Raul; Hernández, Hernán; Baez, Sandra; Migeot, Joaquín; Fittipaldi, Sol; Maito, Marcelo; Legaz, Agustina; Godoy, Maria; Moguilner, Sebastián; Cruzat, Josephine; Coronel, Carlos; Tagliazucchi, Enzo; Santamaria, Hernando; Reyes, Pablo; Matallana, Diana; Avila, José; Slachevsky Chonchol, Andrea; Behrens, María; Custodio, Nilton; Cardona, Juan; Brusco, Luis; Bruno, Martin; Sosa, Ana; Pina, Stefanie; Takada, Leonel; Franca, Elisa de Paula; Possin, Katherine; De Oliveira, Maira; Hu, Kun; Lawlor, Brian; Yokoyama, Jennifer; Miller, Bruce; Lopera, Francisco; Martin, Adolfo; Medel, Vicente; Ibañez, Agustin; Gonzalez, CeciliaBackground: White matter hyperintensities (WMHs) are a core manifestation of normal and pathological aging and are potentially linked to geographical differences in social and physical exposomes. Previous studies have not examined the impact of WMHs burden on neurodegeneration and cognition in healthy controls (HCs) and patients with Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD) across geographic regions. This study addressed this gap by assessing the impact of WMHs burden on participants with and without dementia from Latin America (LA) and the United States (US). Methods: The study comprised 994 participants, including HCs (n = 402), AD (n = 359), and bvFTD subjects (n = 233) from LA and the US. WMHs and their association with grey matter (GM) atrophy, assessed through GM volume and cortical thickness, were evaluated and compared among groups (HCs, AD, and bvFTD) in LA and the US using a voxel-wise brain imaging approach (p < 0.05 family-wise error-corrected for multiple comparisons, minimum cluster size = 50 voxels). Multiple regressions analysis were employed to examine geographic differences in WMHs burden, WMHs-GM associations, and the effect of WMHs on cognitive performance, as assessed by the Mini-Mental State examination. Results: In the LA cohort only, higher WMHs load was associated with greater GM atrophy across all groups (HCs, AD, bvFTD), with a specific neurodegenerative pattern involving orbitofrontal, cingulate, and temporal areas. HCs from LA showed a greater WMHs load than their US counterparts, and this effect was dependent on GM atrophy. Finally, WMHs burden negatively impacted cognitive performance in dementia subjects, with a greater effect observed in bvFTD subjects from the US. Conclusion: WMHs have a more pronounced impact on neurodegeneration across the LA cohort, with a worse impact on HCs, which also show higher WMHs burden than their US counterparts. This could increase the risk of developing dementia. Moreover, WMHs burden differentially impacts cognition, with a greater negative effect observed in bvFTD subjects from the US. These findings highlight geographic variations in WMHs-related conditions, offering valuable insights for tailored future research.