Neurología Cognitiva.artículos

Characterizing circadian rest-activity rhythm patterns across Alzheimer's disease continuum in Down syndrome

Fri, 01 May 2026 00:00:00 GMT

Characterizing circadian rest-activity rhythm patterns across Alzheimer's disease continuum in Down syndrome Giménez, Sandra; Vaqué-Alcázar, Lídia; Clos, Susana; Benejam, Bessy; Carmona-Iragui, María; Maure Blesa, Lucia; Videla, Laura; Zhu, Nuole; Altuna, Miren; Arranz, Javier; Barroeta, Isabel; Rodríguez-Baz, Íñigo; Bejanin, Alexandre; Bueno, Ana; Fernández, Susana; Del Hoyo Soriano, Laura; Pertierra, Lucía; Alcolea, Daniel; Miller, Bruce; Grinberg, Lea T. Introduction: Sleep and circadian rest-activity rhythm (RAR) disruption may bidirectionally relate to Alzheimer's disease (AD). Down syndrome (DS), the most common genetic cause of AD, presents sleep disorders, yet RAR patterns across the DS-associated AD continuum remain uncharacterized. Methods: We analyzed 7-day wrist actigraphy in 140 adults with DS (108 asymptomatic; 32 AD dementia) and 41 unimpaired controls. General linear models, adjusted for age, sex, sleep efficiency, and obstructive sleep apnea (OSA) severity, tested group differences, with interaction terms included to evaluate group-specific associations. Results: DS showed lower relative amplitude and higher nocturnal activity, already in asymptomatic individuals. Rhythm strength declined further with AD progression, while regularity and phase timing remained preserved until dementia. Findings were independent of sleep duration and OSA. Discussion: Adults with DS showed early RAR disturbance that progressed across the AD continuum, paralleling sporadic AD. Circadian RAR features may be scalable biomarkers of AD progression.

Regression-based normative data for neuropsychological assessment in Buenos Aires, Argentina: RAVLT, trail making test, digit span, and verbal fluency

Mon, 11 May 2026 00:00:00 GMT

Regression-based normative data for neuropsychological assessment in Buenos Aires, Argentina: RAVLT, trail making test, digit span, and verbal fluency Corvalán, Nicolás; Morello García, Florentina; Leiva, Samanta; Allegri, Ricardo Francisco; Crivelli, Lucía Objective: To develop regression-based normative data for a set of widely used neuropsychological tests and to provide a freely accessible normative data calculator for use in Buenos Aires, Argentina. Methods: Participants were drawn from a large clinical dataset and selected to reflect preserved global cognition, intact memory performance, and functional independence. Regression-based norms were developed for the Rey Auditory Verbal Learning Test, Verbal Fluency, Trail Making Test, and Digit Span tasks. For each model, predictors included age, sex, and years of education, as well as polynomial terms and interaction effects; final models were obtained via stepwise backward elimination procedures. Model assumptions were evaluated, and predictive performance was estimated using 10-fold cross-validation. Results: 393 participants met inclusion criteria. Age was negatively associated with verbal memory, fluency, and executive function, whereas higher educational attainment was associated with better performance. Women outperformed men in verbal memory and phonological fluency. Demographic variables explained between 2% and 23% of variance across tests. An open-access calculator was developed to facilitate individualized normative estimation in clinical settings. Conclusions: This study provides locally developed, regression-based norms for neuropsychological assessment in Buenos Aires – Argentina, addressing the lack of culturally relevant norms and limitations of traditional methods.

Can Yerba Mate Reduce the Risk of Cognitive Impairment? A pilot study

Tue, 23 Dec 2025 00:00:00 GMT

Can Yerba Mate Reduce the Risk of Cognitive Impairment? A pilot study Gilbert, Afra; Gatto, Emilia M.; Chocobar, Nicolas; Seguí, Josefina; Crotti, Beatriz; Cubas Guillen, Jonathan Fernando; Merchan del Hierro, Xavier; Bacigalupe, Lucia; Persi, Gabriel; Melcon, Carlos Mario; O'Neill, Santiago; Múnera Martínez, Claudia Patricia; Sierra Sanjurjo, Natalia; Rojas, Galeno J.; Tribbia,Teresita Liliana; Taravini, Irene Background: Yerba mate (YM), an infusion made from Ilex paraguariensis, is widely consumed in Argentina and other South American countries. Experimental studies have shown that YM enhances antioxidant defenses, increases chaperonin expression, and reduces AChE activity and Aβ expression. Our objective is to evaluate the potential association between YM consumption and the risk of developing cognitive impairment (CI). Method: This study was conducted at the Trinidad Mitre Hospital and Favaloro Foundation in Buenos Aires, Argentina, from January 2023 to December 2024. A structured survey was administered to individuals aged ≥50 years who underwent neurocognitive testing. Demographic, epidemiological, and lifestyle data were collected, focusing on YM consumption habits. The control group consisted of individuals with Clinical Dementia Rating (CDR) 0, while the case group included those with CDR ≥0.5 and amnestic profile. Logistic regression was used to analyze the association between the outcome and exposure, adjusted for age and gender. Result: 39 controls‐C‐, mean age 68.9 ±8.5 y.o. and 43 patients‐ P‐, mean age 73.2± 9.87 y.o. were included, (p = NS). The mean years of education are similar in both groups C 14.8±3.24 vs. P: 14.1 ±3.54. This suggest a possible association between regular consumption of YM and a lower risk of CI (OR 0.76, 95% CI 0.20 ‐ 2.73). Regular YM consumers showed better cognitive performance in logical memory (immediate and delayed recall) and serial word learning. Conclusion: This pilot study suggests a possible association between YM consumption and reduced CI risk, consistent with previous research. Larger studies are needed to validate this association and explore underlying mechanisms.

Baseline Results Investigate APOE‐Memory Connection in Latin‐American Population at Risk for Dementia ‐ LatAm‐FINGERS Initial Insights

Sun, 21 Dec 2025 00:00:00 GMT

Baseline Results Investigate APOE‐Memory Connection in Latin‐American Population at Risk for Dementia ‐ LatAm‐FINGERS Initial Insights Vasconcelos Friedlaender, Clarisse; Cruz de Souza, Leonardo; Tonidandel Barbosa, Maira; Braga Gomes, Karina; Gonçalves Tosatti, Jéssica Abdo; de Faria Rocha, João Victor; Melillo Cardoso, Davi; Machado Prates, Marcelo; Lopes, Andre Luis; Silva Vieira, Vitoria; Ribeiro Jeunon, Vinicius; Ferreira de Souza, Letícia Maria; Soares Figueiredo, Lais; Andrades, Andreia; Crivelli, Lucía; Calandri, Ismael Luis; Martin, Maria Eugenia; Allegri, Ricardo Francisco; Sevlever, Gustavo Emilio; Surace, Ezequiel Ignacio Background: Latin America (LA) faces heightened vulnerability to modifiable dementia risk factors. Early identification of at‐risk individuals is crucial for implementing effective preventive strategies. The Free and Cued Selective Reminding Test with Immediate Recall (FCSRT‐IR) is promising in early detection of mnemonic impairment, with high sensitivity and specificity for Alzheimer's Disease (AD) risk. While sociodemographic and genetic factors, including APOE ε4 genotype, are associated with elevated dementia risk, their influence on cognitive performance in LA populations remains unclear. We aim to investigate sociodemographic factors and APOE ε4 genotype influence on mnemonic performance in high‐risk LA individuals. Method: Cross‐sectional analysis of LatAm‐FINGERS baseline data, a randomized, multicenter trial evaluating non‐pharmacological interventions for cognitive decline prevention in LA. Inclusion criteria: age 60‐77 years; CAIDE ≥ 6; ‐1.5 ≤ z score ≤ 0 on MMSE or CERAD word list. Exclusion criteria: MMSE < 20; dementia; illiteracy. Participants from Argentina, Brazil, Chile, and Uruguay were included. Memory assessment used FCSRT‐IR and SOMI (Stages of Objective Memory Impairment) classification. APOE genotyping was performed on blood samples using PCR‐RFLP analysis. Jamovi software (v2.3) analyzed correlations and associations (p < 0.05). Result: Sample (N = 358 participants): age 67.75 ± 4.86 years; education 13.41 ± 3.14 years; 72.3% female; 61.2% white; 22.3% APOE ε4 carriers. FCSRT‐IR scores correlated significantly with sociodemographics (p < .001) and varied among countries (p < .001). SOMI distribution: 58% SOMI‐0 (preserved memory), 27.6% SOMI‐1/2 (mild impairment). Argentina showed 36% in SOMI‐3/4 (severe impairment); Uruguay 75% in SOMI‐0. No significant sociodemographic differences were found between APOE ε4 carriers/non‐carriers. Non‐carriers performed better on FCSRT‐IR, significant only for identification score (p = .017). No significant APOE ε4‐SOMI association. Conclusion: Sociodemographic profile significantly influences memory performance, while APOE ε4 genotype shows limited association. This suggests environmental and social factors may play a more central role in cognitive performance than genetic predisposition in LA populations.