Neurología Cognitiva

Executive Functions in Latin American Older Adults: Exploring the Concept Shifting Test and Its Relationship with the APOE Gene in a Cross‐Sectional Sample from the LatAm‐FINGERS Study

Fri, 26 Dec 2025 00:00:00 GMT

Executive Functions in Latin American Older Adults: Exploring the Concept Shifting Test and Its Relationship with the APOE Gene in a Cross‐Sectional Sample from the LatAm‐FINGERS Study Melillo Cardoso, Davi; Vasconcelos Friedlander, Clarisse; Sanches Yassuda, Monica; Cruz de Souza, Leonardo; Crivelli, Lucía; Kimie Suemoto, Claudia; Martin, Maria Eugenia; Calandri, Ismael Luis; Acosta‐Baena, Natalia; Surace, Ezequiel Ignacio; Damian, Andrés; Da Graça Morais Martin, Maria; Vigil‐Martinez, Ana; Henrique Cançado, Gustavo; Salinas‐Contreras, Rosa Maria; Custodio, Belen; Cusicanqui, María Isabel; Delgado, Carolina; Sevlever, Gustavo Emilio; Allegri, Ricardo Francisco Background Latin America (LA) faces high vulnerability to dementia risk factors. Early detection of cognitive decline, particularly in executive functions (EF), is crucial. The Trail Making Test (TMT) has limitations, while the Concept Shifting Test (CST) offers potential advantages but lacks LA adaptation. This study examines CST's correlation with other EF tests and its relationship with APOE‐ε4 in older adults. Methods Cross‐sectional analysis of LatAm‐FINGERS baseline data, including TMT, CST, Stroop Test, and fluency tasks. APOE genotyping used PCR‐RFLP analysis. Jamovi software (v2.3) analyzed correlations (p < 0.05). Results Sample: 1,143 individuals from 11 LA countries. Mean age = 67.4 years (±4.7), education = 13.2 years (±3.5), 73.9% women, 57.3% mixed‐race. 21.4% carried APOE‐ε4 allele. Mean CST shifting score: 16.0 (±19.3). Significant correlations with age (𝜌=0.085; p = 0.009) and education (𝜌 = ‐0.201; p <0.001). No sex differences (p = 0.172). CST shifting score showed moderate correlation with TMT‐flexibility (𝜌=0.372; p <0.001), weak correlations with Stroop (𝜌=‐0.175; p <0.001), semantic (𝜌=‐0.133; p <0.001) and phonemic fluency (𝜌=‐0.184; p <0.001). No significant differences in CST shifting (p = 0.951) or TMT‐flexibility (p = 0.767) between APOE‐ε4 groups. Conclusions Weak correlations between CST shifting, Stroop‐flexibility, and fluency tasks suggest they assess different EF aspects. The moderate CST‐TMT correlation may indicate refined cognitive flexibility measurement in CST. While useful for EF assessment in LA, CST doesn't replace TMT. Diverse tools are crucial for early dementia detection. The lack of association between APOE‐ε4 and cognitive scores emphasizes the importance of assessment regardless of genetic risk.

Cognitive and neuroimaging trajectories in the behavioral variant of Alzheimer's disease

Fri, 26 Dec 2025 00:00:00 GMT

Cognitive and neuroimaging trajectories in the behavioral variant of Alzheimer's disease Calandri, Ismael Luis; Phillips, Jeffrey S.; Tideman, Pontus; Singleton, Ellen Hanna; La Joie, Renaud; van der Flier, Wiesje M.; Jonkman, Laura E.; Hansson, Oskar; Rabinovici, Gil D.; Pijnenburg, Yolande A. L.; Ossenkoppele, Rik; Mastenbroek, Sophie E. Background The behavioral variant of Alzheimer's disease (bvAD) is a rare atypical presentationcharacterized by early and prominent behavioral changes, clinically akin to the behavioral variant of fronto‐temporal dementia (bvFTD). The natural history of bvAD is poorly understood. This study investigates the progression of bvAD in a multinational cohort, comparing bvAD with matched bvFTD and typical AD (tAD) groups. Method We analyzed 81 bvAD participants from four centers and matched them by age, sex, and education to bvFTD (n = 80), tAD (n = 81), and controls (n = 78). Participants completed longitudinal clinical assessments and underwent repeated structural MRI. We combined neurocognitive variables into domain‐specific composites. Furthermore, we extracted cortical thickness and volumetric MRI data using FreeSurfer andcomputed atemporal AD‐signature and a frontal region‐of‐interest. Linear mixed models were used to evaluate cognitive and neuroimaging trajectories. The model coefficients are presented as standardized (β), and the effect is assessed through estimated marginal means (EMM). Result Demographic features are shown in Table 1. Subjects with bvAD exhibited significant decline in executive function (β=‐0.62, 95%CI[‐1.02, ‐0.22], p = 0.03, EMM=‐0.19), memory (β=‐1.62, 95%CI[‐1.90, ‐1.33], p < 0.001, EMM=‐0.49), language (β=‐0.95, 95%CI[‐1.31, ‐0.59], p < 0.01, EMM=‐0.18), and visuospatial function (β=‐0.80, 95%CI[‐1.31, ‐0.28], p < 0.05) compared to controls. Compared to bvFTD, individuals with bvAD showed relatively greater memory (p = 0.005) and language (p = 0.04) preservation over time, while no significant differences were observed in visuospatial function (p = 0.65) or executive function (p = 0.4). In contrast, bvAD did not differ significantly from tAD in memory (p = 0.1), language (p = 0.6), visuospatial function (p = 0.99), or executive function. Individuals with bvAD exhibited significant decline in the AD‐signature (β=‐0.91, 95%CI[‐1.34, ‐0.48], EMM=‐0.49) and frontal ((β=‐0.66, 95%CI[‐1.16, ‐0.15], EMM=‐0.29) regions‐of‐interest compared to controls. Compared to tAD, no significant differences were found in both regions of interest (p = 0.61, p = 0.91). Compared to bvFTD, individuals with bvAD showed significantly greater atrophy in the AD‐signature regions (p = 0.02) and significantly less atrophy in frontal lobe (p = 0.03). Conclusion The progression of bvAD differs both cognitivelyand anatomically from bvFTD, while showing a progression pattern that is very similar to tAD. These results underscore the importance of investigating AD pathology in the context of cognitive‐behavioral decline.

CADASIL Argentine Registry: Study Design and Preliminary Data

Mon, 01 Jan 2024 00:00:00 GMT

CADASIL Argentine Registry: Study Design and Preliminary Data Ardohain Cristalli, Carolina Agata; Rosales, Julieta Soledad; Gonzalez, Fabio; Selvaggi, Valentin; Alonso, Julián Martín; López, Juan Ignacio; Aguilar, Martín Santiago; Kauffman, Marcelo; Saks, Danit G.; Allegri, Ricardo Francisco; Sevlever, Gustavo Emilio; Chaves, Hernán; Cristalli, Diana Olga; Calandri, Ismael Luis Background: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), the most common hereditary small vessel disease, leads to early-onset stroke and vascular cognitive impairment (VCI). Despite its importance, data from Latin America remain scarce. The CADASIL Argentine registry (CADASILAr) was created to harmonize clinical data, promote international collaboration, and provide a reproducible, longitudinal framework to study disease progression and expand to neighboring countries. This study aims to present the cohort design and preliminary results from the cross-sectional phase. Method: CADASILAr was developed to document demographic, clinical, imaging, and genetic features of CADASIL patients and to explore factors associated with disease progression and cognitive decline in an Argentinian multisite cohort. The study includes two phases: (1) a cross-sectional phase (CADASILAR-C) and (2) a longitudinal phase (CADASILAR-Long), following adults aged ≥18 years with genetically confirmed or suspected CADASIL. Variables collected include demographics, symptom onset, clinical features, neuroimaging, genetic data, and vascular risk factors. The study also examines socio-economic disparities, integrates biobanks, and harmonizes data collection with international CADASIL and dementia registries. Longitudinal followups are planned annually over 5 years (Figure 1), with cognitive batteries aligned with international cohorts and a brain donation program to establish a CADASIL brain bank in Argentina. Result: Preliminary data from 90 patients (50% female) show a mean age of 43.8±11.9 years, with family history in 91.6% (Figure 2). The most common clinical presentations were cerebrovascular events (72.9%), cognitive impairment (56.7%), and migraine (69%). The most frequent comorbidities included hypertension (64%) and dyslipidemia (55%). Among 86 confirmed cases, 63 were diagnosed through genetic testing and 20 through skin biopsy. Genetic analysis identified cysteine-altering NOTCH3 mutations in all confirmed cases, predominantly affecting epidermal growth factor-like repeats (Figure 3). Of the 33 patients assessed with the MMSE, the median score was 28 (IQR: 22–29). Conclusion: CADASILAr is the first systematic effort to study this disease in Latin America and the twelfth global CADASIL registry. By integrating baseline and longitudinal data, it offers a robust platform to investigate genetic, neuroimaging, and cognitive outcomes while fostering international collaborations to advance research and understanding of CADASIL.

Clinical Validation of the SECONDs Tool for Evaluating Disorders of Consciousness in Argentina

Tue, 07 Oct 2025 00:00:00 GMT

Clinical Validation of the SECONDs Tool for Evaluating Disorders of Consciousness in Argentina Russo, María Julieta; Sampayo, María de la Paz; Arias, Paula; García, Vanina; Gambero, Yanina; Maiarú, Mariano; Deschle, Florencia; Pavón, Hernán Background: The Coma Recovery Scale-Revised (CRS-R) is the gold standard for diagnosing chronic disorders of consciousness (DoC); however, its clinical utility is limited by lengthy administration and the need for specialized training. The Simplified Evaluation of Disorders of Consciousness (SECONDs) provides a faster and more user-friendly alternative. Objective: This study aims to evaluate the validity and reliability of the Argentine adaptation of the SECONDs scale in adults with chronic DoC due to acquired brain injury. Methods: Twenty-nine patients were evaluated over two consecutive days by three blinded raters. On day one, rater A administered the SECONDs (A1) and rater B administered the CRS-R (B) to assess concurrent validity. On day two, rater A repeated the SECONDs (A2), and rater C performed an additional SECONDs assessment (C), permitting evaluation of intra-rater (A1 vs. A2) and inter-rater (A vs. C) reliability. Results: The SECONDs demonstrated excellent intra-rater (ICC = 0.98) and inter-rater (ICC = 0.86) reliability. Concurrent validity with the CRS-R was strong (r = 0.73, p < 0.001). Diagnostic agreement was high between A1 and B (κ = 0.75) and between both A1-A2 and A1-C (κ = 0.82). The median administration time was significantly shorter for the SECONDs (10 vs. 15 min; p < 0.001). Conclusion: The Argentine SECONDs is a valid, reliable, and efficient tool for the clinical assessment of DoC patients in rehabilitation settings.