Browsing by Author "Duro, D"
Now showing 1 - 6 of 6
Results Per Page
Sort Options
- Association between Adipokines and Biomarkers of Alzheimer's Disease: A Cross-Sectional StudyPublication . Letra, L; Matafome, P; Rodrigues, T; Duro, D; Lemos, R; Baldeiras, I; Patrício, M; Castelo-Branco, M; Caetano, G; Seiça, R; Santana, IBACKGROUND: Adipose tissue dysfunction has been implicated in the pathophysiology of Alzheimer's disease. However, the involvement of adipokines, particularly adiponectin, remains unclear. OBJECTIVE: To compare serum and cerebrospinal fluid (CSF) levels of adiponectin, leptin and leptin-to-adiponectin ratio in patients within the spectrum of Alzheimer's disease and evaluate their relationship with classical biomarkers and their value as markers of progression. METHODS: Amnestic mild cognitive impairment (MCI, n = 71) and Alzheimer's dementia (AD, n = 53) subjects were consecutively recruited for serum and CSF adiponectin and leptin determination using an analytically validated commercial enzyme-linked immunosorbent assay (ELISA). Correlations were explored using adjusted Spearman's correlation coefficients. A logistic regression model and ROC analysis were performed to evaluate the staging predictive value of adipokines. RESULTS: Serum adiponectin was 33% higher in AD when compared to MCI patients. Adiponectin CSF levels, similar in both groups, were positively correlated with Aβ42 and cognitive function, though only in women. The area under the ROC curve was 0.673 (95% CI:0.57-0.78) for serum adiponectin as predictor of dementia stage and the cut-off 10.85μg/ml maximized the sum of specificity (87%) and sensitivity (44%). CONCLUSION: Although longitudinal studies are required, we hypothesize that higher serum adiponectin in AD patients constitutes a strategy to compensate possible central signaling defects. In addition, adiponectin might be specifically assigned to neuroprotective functions in women and eventually involved in the female-biased incidence of Alzheimer's disease.
- Discriminative capacity and construct validity of the Clock Drawing Test in Mild Cognitive Impairment and Alzheimer's diseasePublication . Duro, D; Freitas, S; Tábuas-Pereira, M; Santiago, B; Botelho, MA; Santana, IOBJECTIVES: The aim of this study was to analyze the psychometric and diagnostic properties of the Clock Drawing Test (CDT), scored according to the Babins, Rouleau, and Cahn scoring systems, for Mild Cognitive Impairment (MCI) and Alzheimer's disease (AD) screening, and develop corresponding cutoff scores. Additionally, we assessed the construct validity of the CDT through exploratory and confirmatory factor analysis. METHODS: We developed a cross-sectional study of ambulatory MCI and AD patients, divided in two clinical groups (450 MCI and 250 mild AD patients) and a normal control group (N = 400). All participants were assessed with the CDT, Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) for convergent validity. RESULTS: The selected scoring systems presented adequate validity and reliability values. The proposed cutoff scores showed 60 to 65% sensitivity and 58 to 62% specificity to identify MCI patients. The corresponding values for AD were 84 to 90% sensitivity and 76 to 78% specificity. Exploratory and confirmatory factor analysis revealed that the Babins scoring system had good construct validity and allowed us to propose a three-factor model for this system. CONCLUSIONS: Our results confirmed the complexity of the CDT and support it as a cognitive screening instrument particularly sensitive to AD. The use of the CDT with MCI patients should be interpreted with more caution due to the lower sensitivity and specificity for milder forms of cognitive impairment.
- Erlangen Score as a tool to predict progression from mild cognitive impairment to dementia in Alzheimer's diseasePublication . Baldeiras, I; Santana, I; Leitão, MJ; Vieira, D; Duro, D; Mroczko, B; Kornhuber, J; Lewczuk, PBACKGROUND: The previously described and validated Erlangen Score (ES) algorithm enables interpretation of the cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD), ordering them on an ordinal scale: from neurochemically normal (ES = 0) through improbable AD (ES = 1), possible AD (ES = 2 or 3), to probable AD (ES = 4). Here we assess the accuracy of the ES in predicting hazards of progression from the mild cognitive impairment (MCI) stage of AD to the dementia stage of the disease (Alzheimer's disease dementia (ADD)) in a novel, single-center cohort. METHODS: Baseline CSF biomarkers (amyloid beta (Aβ) 1-42, Aβ42/40, Tau, and pTau181), interpreted according to the ES, were used to estimate time to progression from the MCI stage of AD to ADD, conditional on age, gender, APOE ε4 genotype, and Mini Mental State Examination score in 144 MCI subjects, using the Extended Cox Model; the subjects were followed-up until they developed dementia or until they had been cognitively stable for at least 2 years. In addition, ES distributions were studied in 168 ADD cases and 66 neurologic controls. Further, we stratified MCI patients into those who progressed to ADD faster (within 3 years, n = 47) and those who progressed slower (n = 74). RESULTS: The distributions of the ES categories across the four diagnostic groups (Controls, MCI-Stable, MCI-AD, and ADD) were highly significantly different (Kruskal-Wallis χ2(df = 3) = 151.4, p < 0.001), with significant contrasts between each pair (p < 0.005), except between the ADD and the MCI-AD groups (p = 1.0). MCI patients with ES = 2 or 3 had 6-8 times higher hazards to progress to ADD compared to patients with ES = 0 or 1 in the first 3 follow-up years, and then their hazards decreased to those of the group with ES = 0 or 1. Patients with ES = 4 had hazards 8-12 times higher compared to the ES = 0 or 1 group. Faster progressors with ES = 2 or 3 had, in comparison to slower progressors, significantly lower Aβ1-42, Aβ1-40, and Aβ42/40, but comparable Tau and pTau181. A highly significant difference of the ES distributions between these two groups was observed (p < 0.001). CONCLUSIONS: Our current results reconfirm and extend the conclusions of the previously published report that the Erlangen Score is a useful tool facilitating interpretation of a complex pattern of the CSF AD biomarkers.
- Frontotemporal dementia: neuroanatomical correlates of an atypical presentationPublication . Felix-Morais, R; Letra, L; Duro, D; Santana, IFrontotemporal dementia (FTD) is a heterogeneous group of disorders characterised by frontal and temporal lobes atrophy. Three different clinical subtypes are recognised: behavioural variant, progressive non-fluent aphasia and semantic dementia. Neuroanatomical associations in a diffuse neurodegenerative disease such as FTD should be interpreted carefully; however, each FTD subtype has provided a clinical model that has contributed immensely to our understanding of clinical/neuroanatomical relationships. This case report and recent studies suggest that neuroanatomical findings concerning face-processing mechanisms in FTD can identify the brain regions that are critical for face processing. As seen in this case, right fusiform gyrus atrophy seems to be implied in the aetiology of prosopagnosia.
- MicroRNA deregulation and chemotaxis and phagocytosis impairment in Alzheimer's diseasePublication . Guedes, JR; Santana, I; Cunha, C; Duro, D; Almeida, MR; Cardoso, AM; Pedroso de Lima, MC; Cardoso, ALINTRODUCTION: Mononuclear phagocytes play a critical role during Alzheimer's disease (AD) pathogenesis due to their contribution to innate immune responses and amyloid beta (Aβ) clearance mechanisms. METHODS: Blood-derived monocytes (BDMs) and monocyte-derived macrophages (MDMs) were isolated from blood of AD, mild cognitive impairment (MCI) patients, and age-matched healthy controls for molecular and phenotypic comparisons. RESULTS: The chemokine/chemokine receptor CCL2/CCR2 axis was impaired in BDMs from AD and MCI patients, causing a deficit in cell migration. Changes were also observed in MDM-mediated phagocytosis of Aβ fibrils, correlating with alterations in the expression and processing of the triggering receptor expressed on myeloid cells 2 (TREM2). Finally, immune-related microRNAs (miRNAs), including miR-155, -154, -200b, -27b, and -128, were found to be differentially expressed in these cells. DISCUSSION: This work provides evidence that chemotaxis and phagocytosis, two crucial innate immune functions, are impaired in AD and MCI patients. Correlations with miRNA levels suggest an epigenetic contribution to systemic immune dysfunction in AD.
- Multiple Dural Arteriovenous Fistulas Presenting as Rapidly Progressive DementiaPublication . Mendonça, N; Santos, G; Duro, D; Machado, E; Goulão, A; Santana, IINTRODUCTION:Dural arteriovenous fistulas (DAVFs) are important causes of neurological dysfunction and are many times misdiagnosed. Particularly in older populations, DAVFs may present with a selective cognitive dysfunction. CASE REPORT: The authors describe a 70-year-old woman presenting with a rapidly progressive dementia, very similar in presentation to prion disease. Neuroimaging showed multifocal DAVFs associated with venous thrombosis and white matter changes, suggesting that impaired cerebral circulation due to venous hypertensive encephalopathy caused the patient's dementia. Prompt treatment of some of the abnormal shunts with endovascular embolization resulted in a clinically relevant improvement. Subsequent clinical improvement was achieved with anticoagulation, although no cause or predisposing factor was documented that could have led to the development of the venous thrombosis. CONCLUSIONS:Neurologists should maintain a high degree of suspicion to avoid missing the diagnosis of DAVFs that are potentially treatable lesions.