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Scientific knowledge about dementia: From the Global South to the world
(Wiley, 2026-03)
Timothy Daly
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Ignacio López‐Barrenechea
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Paulina Vergara
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Faheem Arshad
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Avanthi Paplikar
<jats:title>Abstract</jats:title> <jats:p>Most people with dementia live in low‐ and middle‐income countries (LMICs), but scientific knowledge about dementia is dominated by Global North perspectives. This interdisciplinary article combines expertise from Latin America, India, and Europe, using a mixed‐methodology approach that incorporates expert discussions, a narrative review, and five illustrative case studies. The review on dementia in the Global South yielded 82 results, highlighting the themes of challenges in diagnosis and assessment, socioeconomic and systemic barriers to cognitive health and care pathways, and the need for local capacity building. Those themes were then used to interpret case studies on functionality assessment, genetic heterogeneity, bilingualism, structural inequalities, and North–South collaborations. These cases highlight the misalignment between Northern frameworks on dementia and the realities of LMICs, and illustrate the potential for locally generated knowledge to enrich global understanding. Through several rounds of expert discussion, we identified priorities for Global South perspectives for dementia research and policy.</jats:p>
2
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Psychiatric genetics in the diverse landscape of Latin American populations
(Springer Science and Business Media LLC, 2025-04-02)
Estela M. Bruxel
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Diego L. Rovaris
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Sintia I. Belangero
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Gabriela Chavarría-Soley
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Alfredo B. Cuellar-Barboza
4
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Comprehensive Analysis of Genetic Contributions to Alzheimer’s Disease and Frontotemporal Dementia in Admixed Latin American Populations
(Wiley, 2024-12)
Juliana Acosta‐Uribe
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Stefanie Danielle Pina Escudero
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J. Nicholas Cochran
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Jared W Taylor
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Caroline Warly Solsberg
<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Most research initiatives have emerged from high‐income countries (HIC), leaving a gap in understanding the disease’s genetic basis in diverse populations like those in Latin American countries (LAC). ReDLat tackles this gap, focusing on LAC’s unique genetics and socioeconomic factors to identify specific Alzheimer’s Disease (AD) and Frontotemporal Dementia (FTD) risk factors in Mexico, Colombia, Peru, Chile, Argentina, and Brazil.</jats:p></jats:sec><jats:sec><jats:title>Method</jats:title><jats:p>We employed a comprehensive genetic analysis approach, integrating Whole Genome Sequencing (WGS), Exome Sequencing, and SNP arrays to understand the cohort’s unique genetic architecture. We conducted ancestry analysis and searched for disease‐causing variants with mendelian inheritance, genome‐wide association studies (GWAS), rare variant enrichment, and evaluation of Polygenic Risk Scores (PRS).</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>We recruited and genotyped an initial cohort of 1046 participants with AD, 423 with FTD, and 855 healthy controls (HC) between 2020 and 2023. Analysis is ongoing, and we expect to sequence ∼600 additional samples in the coming months. Ancestry analysis revealed tri‐continental admixture, except for Brazil, which showed an additional Asian component (Figure 1). Top candidate gene rare variant enrichment associations (SKAT p < 0.05) were <jats:italic>TREM2</jats:italic> for FTD and <jats:italic>ABCA7</jats:italic> and <jats:italic>ABCA1</jats:italic> for AD. GWAS identified a robust association with the <jats:italic>APOE</jats:italic> locus on chromosome 19 in AD vs. HC.. We tested an AD PRS developed in European populations by Bellenguez et al (2020). on our cohort using 83 single‐nucleotide polymorphisms.. The PRS modestly distinguishes between all patients and HC (p = 2.4 × 10^‐12), AD vs. HC (p = 2.2 × 10^‐12), and even FTD vs. HC (p = 4.3 × 10^‐5), albeit with modest separation between groups, as expected for its application in a genetically admixed population.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>Our findings represent a pivotal step in understanding the genetic landscape of AD and FTD in admixed populations. They underscore the importance of including diverse populations in genetic research, paving the way for future studies. These findings have the potential to inform more personalized approaches to the diagnosis and treatment of neurodegenerative diseases in diverse global populations, as well as identify novel targets for therapeutic development.</jats:p></jats:sec>
3
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Author Correction: Neurocognitive correlates of semantic memory navigation in Parkinson’s disease
(2024)
Felipe Diego Toro-Hernández
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Joaquín Migeot
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Nicolás Marchant
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Daniela Olivares
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Franco Ferrante
1
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Neurocognitive correlates of semantic memory navigation in Parkinson’s disease
(2024)
Felipe Diego Toro-Hernández
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Joaquín Migeot
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Nicolás Marchant
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Daniela Olivares
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Franco Ferrante
<jats:title>Abstract</jats:title><jats:p>Cognitive studies on Parkinson’s disease (PD) reveal abnormal semantic processing. Most research, however, fails to indicate which conceptual properties are most affected and capture patients’ neurocognitive profiles. Here, we asked persons with PD, healthy controls, and individuals with behavioral variant frontotemporal dementia (bvFTD, as a disease control group) to read concepts (e.g., ‘sun’) and list their features (e.g., <jats:italic>hot</jats:italic>). Responses were analyzed in terms of ten word properties (including concreteness, imageability, and semantic variability), used for group-level comparisons, subject-level classification, and brain-behavior correlations. PD (but not bvFTD) patients produced more concrete and imageable words than controls, both patterns being associated with overall cognitive status. PD and bvFTD patients showed reduced semantic variability, an anomaly which predicted semantic inhibition outcomes. Word-property patterns robustly classified PD (but not bvFTD) patients and correlated with disease-specific hypoconnectivity along the sensorimotor and salience networks. Fine-grained semantic assessments, then, can reveal distinct neurocognitive signatures of PD.</jats:p>
2Scopus© Citations 15
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Automated free speech analysis reveals distinct markers of Alzheimer’s and frontotemporal dementia
(2024)
Pamela Lopes da Cunha
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Fabián Ruiz
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Franco Ferrante
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Lucas Federico Sterpin
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Agustín Ibáñez
<jats:p>Dementia can disrupt how people experience and describe events as well as their own role in them. Alzheimer’s disease (AD) compromises the processing of entities expressed by nouns, while behavioral variant frontotemporal dementia (bvFTD) entails a depersonalized perspective with increased third-person references. Yet, no study has examined whether these patterns can be captured in connected speech via natural language processing tools. To tackle such gaps, we asked 96 participants (32 AD patients, 32 bvFTD patients, 32 healthy controls) to narrate a typical day of their lives and calculated the proportion of nouns, verbs, and first- or third-person markers (via part-of-speech and morphological tagging). We also extracted objective properties (frequency, phonological neighborhood, length, semantic variability) from each content word. In our main study (with 21 AD patients, 21 bvFTD patients, and 21 healthy controls), we used inferential statistics and machine learning for group-level and subject-level discrimination. The above linguistic features were correlated with patients’ scores in tests of general cognitive status and executive functions. We found that, compared with HCs, (i) AD (but not bvFTD) patients produced significantly fewer nouns, (ii) bvFTD (but not AD) patients used significantly more third-person markers, and (iii) both patient groups produced more frequent words. Machine learning analyses showed that these features identified individuals with AD and bvFTD (AUC = 0.71). A generalizability test, with a model trained on the entire main study sample and tested on hold-out samples (11 AD patients, 11 bvFTD patients, 11 healthy controls), showed even better performance, with AUCs of 0.76 and 0.83 for AD and bvFTD, respectively. No linguistic feature was significantly correlated with cognitive test scores in either patient group. These results suggest that specific cognitive traits of each disorder can be captured automatically in connected speech, favoring interpretability for enhanced syndrome characterization, diagnosis, and monitoring.</jats:p>
2Scopus© Citations 22
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Multivariate word properties in fluency tasks reveal markers of Alzheimer's dementia
(2023)
Franco J. Ferrante
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Joaquín Migeot
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Agustina Birba
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Lucía Amoruso
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Gonzalo Pérez
<jats:title>Abstract</jats:title><jats:sec><jats:title>INTRODUCTION</jats:title><jats:p>Verbal fluency tasks are common in Alzheimer's disease (AD) assessments. Yet, standard valid response counts fail to reveal disease‐specific semantic memory patterns. Here, we leveraged automated word‐property analysis to capture neurocognitive markers of AD vis‐à‐vis behavioral variant frontotemporal dementia (bvFTD).</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>Patients and healthy controls completed two fluency tasks. We counted valid responses and computed each word's frequency, granularity, neighborhood, length, familiarity, and imageability. These features were used for group‐level discrimination, patient‐level identification, and correlations with executive and neural (magnetic resonanance imaging [MRI], functional MRI [fMRI], electroencephalography [EEG]) patterns.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>Valid responses revealed deficits in both disorders. Conversely, frequency, granularity, and neighborhood yielded robust group‐ and subject‐level discrimination only in AD, also predicting executive outcomes. Disease‐specific cortical thickness patterns were predicted by frequency in both disorders. Default‐mode and salience network hypoconnectivity, and EEG beta hypoconnectivity, were predicted by frequency and granularity only in AD.</jats:p></jats:sec><jats:sec><jats:title>DISCUSSION</jats:title><jats:p>Word‐property analysis of fluency can boost AD characterization and diagnosis.</jats:p></jats:sec><jats:sec><jats:title>Highlights</jats:title><jats:p><jats:list list-type="bullet"> <jats:list-item><jats:p>We report novel word‐property analyses of verbal fluency in AD and bvFTD.</jats:p></jats:list-item> <jats:list-item><jats:p>Standard valid response counts captured deficits and brain patterns in both groups.</jats:p></jats:list-item> <jats:list-item><jats:p>Specific word properties (e.g., frequency, granularity) were altered only in AD.</jats:p></jats:list-item> <jats:list-item><jats:p>Such properties predicted cognitive and neural (MRI, fMRI, EEG) patterns in AD.</jats:p></jats:list-item> <jats:list-item><jats:p>Word‐property analysis of fluency can boost AD characterization and diagnosis.</jats:p></jats:list-item> </jats:list></jats:p></jats:sec>
3Scopus© Citations 10
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The limitations and challenges in the assessment of executive dysfunction associated with real-world functioning: The opportunity of serious games
(2023)
David Martínez-Pernía
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Loreto Olavarría
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Baltasar Fernández-Manjón
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Victoria Cabello
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HENRIQUEZ, FERNANDO
Scopus© Citations 5 2
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Moral Emotions and Their Brain Structural Correlates Across Neurodegenerative Disorders
(2023)
Sandra Baez
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Catalina Trujillo-Llano
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Leonardo Cruz de Souza
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Patricia Lillo
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Gonzalo Forno
<jats:p>Background: Although social cognition is compromised in patients with neurodegenerative disorders such as behavioral variant frontotemporal dementia (bvFTD) and Alzheimer’s disease (AD), research on moral emotions and their neural correlates in these populations is scarce. No previous study has explored the utility of moral emotions, compared to and in combination with classical general cognitive state tools, to discriminate bvFTD from AD patients. Objective: To examine self-conscious (guilt and embarrassment) and other-oriented (pity and indignation) moral emotions, their subjective experience, and their structural brain underpinnings in bvFTD (n = 31) and AD (n = 30) patients, compared to healthy controls (n = 37). We also explored the potential utility of moral emotions measures to discriminate bvFTD from AD. Methods: We used a modified version of the Moral Sentiment Task measuring the participants’ accuracy scores and their emotional subjective experiences. Results: bvFTD patients exhibited greater impairments in self-conscious and other-oriented moral emotions as compared with AD patients and healthy controls. Moral emotions combined with general cognitive state tools emerged as useful measures to discriminate bvFTD from AD patients. In bvFTD patients, lower moral emotions scores were associated with lower gray matter volumes in caudate nucleus and inferior and middle temporal gyri. In AD, these scores were associated with lower gray matter volumes in superior and middle frontal gyri, middle temporal gyrus, inferior parietal lobule and supramarginal gyrus. Conclusion: These findings contribute to a better understanding of moral emotion deficits across neurodegenerative disorders, highlighting the potential benefits of integrating this domain into the clinical assessment.</jats:p>
24Scopus© Citations 3
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Multidimensional inhibitory signatures of sentential negation in behavioral variant frontotemporal dementia
(2022)
Mariano N Díaz-Rivera
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Agustina Birba
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Sol Fittipaldi
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Débora Mola
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Yurena Morera
<jats:title>Abstract</jats:title> <jats:sec> <jats:title>Background</jats:title> <jats:p>Processing of linguistic negation has been associated to inhibitory brain mechanisms. However, no study has tapped this link via multimodal measures in patients with core inhibitory alterations, a critical approach to reveal direct neural correlates and potential disease markers.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>Here we examined oscillatory, neuroanatomical, and functional connectivity signatures of a recently reported Go/No-go negation task in healthy controls and behavioral variant frontotemporal dementia (bvFTD) patients, typified by primary and generalized inhibitory disruptions. To test for specificity, we also recruited persons with Alzheimer's disease (AD), a disease involving frequent but nonprimary inhibitory deficits.</jats:p> </jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>In controls, negative sentences in the No-go condition distinctly involved frontocentral delta (2–3 Hz) suppression, a canonical inhibitory marker. In bvFTD patients, this modulation was selectively abolished and significantly correlated with the volume and functional connectivity of regions supporting inhibition (e.g. precentral gyrus, caudate nucleus, and cerebellum). Such canonical delta suppression was preserved in the AD group and associated with widespread anatomo-functional patterns across non-inhibitory regions.</jats:p> </jats:sec> <jats:sec> <jats:title>Discussion</jats:title> <jats:p>These findings suggest that negation hinges on the integrity and interaction of spatiotemporal inhibitory mechanisms. Moreover, our results reveal potential neurocognitive markers of bvFTD, opening a new agenda at the crossing of cognitive neuroscience and behavioral neurology.</jats:p> </jats:sec>
Scopus© Citations 18 4

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