Risk of New-Diagnosed Atrial Fibrillation After Transient Ischemic Attack.

Background: Transient ischemic attack (TIA) provides a unique opportunity to optimize secondary preventive treatments to avoid subsequent ischemic stroke (SIS). Although atrial fibrillation (AF) is the leading cause of cardioembolism in IS and anticoagulation prevents stroke recurrence (SR), limited data exists about the risk of new-diagnosed AF (NDAF) after TIA and the consequences of the diagnostic delay. The aim of our study was to determine this risk in a cohort of TIA patients with long-term follow-up. Methods: We carried out a prospective cohort study of 723 consecutive TIA patients from January 2006 to June 2010. Median follow-up was 6.5 (5.0-9.6) years. In a subgroup of 204 (28.2%) consecutive patients, a panel of biomarkers was assessed during the first 24 h of the onset of symptoms. Multivariate analyses were performed to find out the associated factors of NDAF. Kaplan-Meier analysis was also performed to analyzed risk of SIS. Results: NDAF was indentified in 116 (16.0%) patients: 42 (36.2%) during admission, 18 (15.5%) within first year, 29 (25%) between one and five years and 27 (23.3%) beyond 5 years. NDAF was associated with sex (female) [hazard ratio (HR) 1.61 (95% CI, 1.07- 2.41)], age [[HR 1.05 (95% CI, 1.03-1.07)], previous ischemic heart disease (IHD) [HR 1.84, (95% CI 1.15-2.97)] and cortical DWI pattern [HR 2.81 (95% CI, 1.87-4.21)]. In the Kaplan-Meier analysis, NT-proBNP ≥ 218.2 pg/ml (log-rank test P < 0.001) was associated with significant risk of NDAF during the first 5 years of follow-up. Patients with NDAF after admission and before 5 years of follow-up had the highest risk of SIS (P = 0.002). Conclusion: The risk of NDAF after TIA is clinically relevant. We identified clinical and neuroimaging factors of NDAF. In addition, NT-proBNP was related to NDAF. Our results can be used to evaluate the benefit of long-term cardiac monitoring in selected patients.

Region-specific vulnerability to lipid peroxidation and evidence of neuronal mechanisms for polyunsaturated fatty acid biosynthesis in the healthy adult human central nervous system.

Lipids played a determinant role in the evolution of the brain. It is postulated that the morphological and functional diversity among neural cells of the human central nervous system (CNS) is projected and achieved through the expression of particular lipid profiles. The present study was designed to evaluate the differential vulnerability to oxidative stress mediated by lipids through a cross-regional comparative approach. To this end, we compared 12 different regions of CNS of healthy adult subjects, and the fatty acid profile and vulnerability to lipid peroxidation, were determined by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS), respectively. In addition, different components involved in PUFA biosynthesis, as well as adaptive defense mechanisms against lipid peroxidation, were also measured by western blot and immunohistochemistry, respectively. We found that: i) four fatty acids (18.1n-9, 22:6n-3, 20:1n-9, and 18:0) are significant discriminators among CNS regions; ii) these differential fatty acid profiles generate a differential selective neural vulnerability (expressed by the peroxidizability index); iii) the cross-regional differences for the fatty acid profiles follow a caudal-cranial gradient which is directly related to changes in the biosynthesis pathways which can be ascribed to neuronal cells; and iv) the higher the peroxidizability index for a given human brain region, the lower concentration of the protein damage markers, likely supported by the presence of adaptive antioxidant mechanisms. In conclusion, our results suggest that there is a region-specific vulnerability to lipid peroxidation and offer evidence of neuronal mechanisms for polyunsaturated fatty acid biosynthesis in the human central nervous system.

Sixty years old is the breakpoint of human frontal cortex aging.

Human brain aging is the physiological process which underlies as cause of cognitive decline in the elderly and the main risk factor for neurodegenerative diseases such as Alzheimer's disease. Human neurons are functional throughout a healthy adult lifespan, yet the mechanisms that maintain function and protect against neurodegenerative processes during aging are unknown. Here we show that protein oxidative and glycoxidative damage significantly increases during human brain aging, with a breakpoint at 60 years old. This trajectory is coincident with a decrease in the content of the mitochondrial respiratory chain complex I-IV. We suggest that the deterioration in oxidative stress homeostasis during aging induces an adaptive response of stress resistance mechanisms based on the sustained expression of REST, and increased or decreased expression of Akt and mTOR, respectively, over the adult lifespan in order to preserve cell neural survival and function.

Utilidad de los nuevos criterios diagnósticos y la introducción de los biomarcadores en el continuum de la enfermedad de Alzheimer / Usefullness of new diagnosis criteria and introduction of biomarkers in Alzheimer’s disease continuum

Objetivos: los nuevos criterios diagnósticos de enfermedad de Alzheimer (EA) y deterioro cognitivo leve (DCL) apoyan la utilización de los biomarcadores. Valoramos la utilidad de añadir los biomarcadores en la práctica clínica habitual para confirmar y/o modificar el grado de certeza en el diagnóstico de EA y DCL. Pacientes y métodos: presentamos 40 pacientes en los que de forma consecutiva se realizó la determinación de biomarcadores en líquido cefalorraquídeo (LCR) (amilode, tau y p-tau) y evaluación neuropsicológica según los criterios establecidos en nuestra unidad. Resultados: presentamos las características demográficas de los pacientes. En el 52 % de los pacientes los biomarcadores permitieron modificar el grado de certeza del diagnóstico. La mayor aportación es poder reclasificar a los pacientes con DCL en pacientes con DCL y alto riesgo de EA (7), riesgo intermedio (6) o riesgo bajo (12). En dos casos de inicio rápidamente progresivo, los biomarcadores fueron compatibles con EA. Además, su determinación basal ayuda a predecir el riesgo de progresión a EA tras 2 años de seguimiento. Conclusiones: la utilización de los biomarcadores en la práctica clínica habitual ayuda a modificar el grado de certeza del diagnóstico clínico y, por tanto, el pronóstico de los pacientes, especialmente en fase prodrómica y en presentaciones atípicas (AU)

Background: The new diagnostic criteria for Alzheimer's disease (AD) and mild cognitive impairment (MCI) supports the use of biomarkers. We appreciate the value of adding biomarkers to routine clinical practice to confirm and/or modify the degree of certainty in the diagnosis of AD and MCI. Methods: We present 40 patients consecutively determining CSF biomarkers (amyloid, tau and p-tau) and neuropsychological evaluation was performed according to the criteria set out in our unit. Results: We present the demographic characteristics of the patients. In 52% of patients allowed biomarkers modify the degree of certainty of the diagnosis. The greatest contribution is to reclassify patients with MCI in MCI patients at high risk of AD (7), intermediate risk (7) or low risk of AD (12). In both cases of rapidly progressive onset biomarkers were consistent with AD. Besides, basal CSF biomarkers are useful to predict progression to AD after two years follow-up. Conclusion: The use of biomarkers in clinical practice helps to modify the degree of certainty of the clinical diagnosis, and therefore the prognosis of patients, especially in prodromal phase and atypical presentations (AU)