94 research outputs found

    Association of cognitive reserve with stroke outcome: a protocol for a systematic review.

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    INTRODUCTION The concept of cognitive reserve (CR) was introduced to account for individual differences in the clinical manifestation of neurodegenerative diseases. Though several mechanisms and risk factors are shared between neurodegeneration and stroke, the effect of CR on poststroke functional outcome has been poorly addressed. This systematic review aims to synthesise the available research evidence on the association of CR with stroke outcome, in order to implement the understanding of interindividual variability in stroke outcome and to improve its prediction. METHODS AND ANALYSIS Cochrane Library, Embase, PubMed, Web of Science and reference lists of relevant literature will be searched for publications on CR proxies (eg, education, years of education, occupational attainment, premorbid intelligence) and stroke outcome, published between 1 January 1980 and 10 March 2022. Two reviewers will independently perform the study selection, data extraction and quality assessment. Disagreements between reviewers will be resolved by a third independent reviewer. The Quality In Prognosis Studies tool will be used to assess the quality of each included study. The primary outcome will be functional outcome after stroke assessed with modified Rankin Scale, activities of daily living (eg, Barthel Index), National Institute of Health Stroke Scale, dichotomised as favourable versus not favourable as well as reported as continuous or ordinal variables. Qualitative and quantitative findings will be summarised and, if possible, data will be synthesised using appropriate meta-analytical methods. The quality of evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation framework. ETHICS AND DISSEMINATION No ethical approval is required as it is a protocol for a systematic review and the data used will be extracted from published studies. The findings from this systematic review will be disseminated in a peer-reviewed scientific journal and presented at conferences. The data will be made freely available. PROSPERO REGISTRATION NUMBER CRD42021256175

    Estruturas Matriciais – Vantagens E Desvantagens Genéricas De Sua Adoção, E Sua Utilização Para Solucionar Uma Crise De Crescimento Em Uma Instituição Privada De Ensino Superior.

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    Abordada e adotada como novidade e como receita infalível de sucesso, tanto pelo meio acadêmico quanto pelo meio empresarial, em anos recentes, a estrutura matricial não pode ser enquadrada em nenhuma dessas categorias. Primeiro, porque data dos meados da década de 50, quando a indústria aeroespacial florescia nos USA; segundo, porque a opção por uma estrutura matricial irá se mostrar mais ou menos adequada a cada caso específico, dependendo do setor de atividade, do tipo de cultura e do ambiente competitivo em que a empresa atua, entre outros fatores. O principal objetivo deste texto é resgatar a importância das estruturas matriciais para empresas que necessitam de agilidade, compartilhamento de conhecimento e otimização das competências individuais de seus profissionais para poder responder às exigências de mercados cada vez mais competitivos e instáveis. O texto contém uma revisão da abordagem de diferentes autores sobre as principais vantagens e desvantagens que uma empresa pode obter ao implantar uma estrutura matricial. Na seqüência, relata-se e analisa-se, também sinteticamente, um caso real de implantação de estrutura matricial em uma instituição privada de ensino superior, apontando as dificuldades e os benefícios resultantes

    Bayesian lesion-deficit inference with Bayes factor mapping: key advantages, limitations, and a toolbox.

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    Statistical lesion-symptom mapping is largely dominated by frequentist approaches with null hypothesis significance testing. They are popular for mapping functional brain anatomy but are accompanied by some challenges and limitations. The typical analysis design and the structure of clinical lesion data are linked to the multiple comparison problem, an association problem, limitations to statistical power, and a lack of insights into evidence for the null hypothesis. Bayesian lesion deficit inference (BLDI) could be an improvement as it collects evidence for the null hypothesis, i.e. the absence of effects, and does not accumulate α-errors with repeated testing. We implemented BLDI by Bayes factor mapping with Bayesian t-tests and general linear models and evaluated its performance in comparison to frequentist lesion-symptom mapping with a permutation-based family-wise error correction. We mapped the voxel-wise neural correlates of simulated deficits in an in-silico-study with 300 stroke patients, and the voxel-wise and disconnection-wise neural correlates of phonemic verbal fluency and constructive ability in 137 stroke patients. Both the performance of frequentist and Bayesian lesion-deficit inference varied largely across analyses. In general, BLDI could find areas with evidence for the null hypothesis and was statistically more liberal in providing evidence for the alternative hypothesis, i.e. the identification of lesion-deficit associations. BLDI performed better in situations in which the frequentist method is typically strongly limited, for example with on average small lesions and in situations with low power, where BLDI also provided unprecedented transparency in terms of the informative value of the data. On the other hand, BLDI suffered more from the association problem, which led to a pronounced overshoot of lesion-deficit associations in analyses with high statistical power. We further implemented a new approach to lesion size control, adaptive lesion size control, that, in many situations, was able to counter the limitations imposed by the association problem, and increased true evidence both for the null and the alternative hypothesis. In summary, our results suggest that BLDI is a valuable addition to the method portfolio of lesion-deficit inference with some specific and exclusive advantages: it deals better with smaller lesions and low statistical power (i.e. small samples and effect sizes) and identifies regions with absent lesion-deficit associations. However, it is not superior to established frequentist approaches in all respects and therefore not to be seen as a general replacement. To make Bayesian lesion-deficit inference widely accessible, we published an R toolkit for the analysis of voxel-wise and disconnection-wise data

    Stroke lesion size:Still a useful biomarker for stroke severity and outcome in times of high-dimensional models

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    BACKGROUND The volumetric size of a brain lesion is a frequently used stroke biomarker. It stands out among most imaging biomarkers for being a one-dimensional variable that is applicable in simple statistical models. In times of machine learning algorithms, the question arises of whether such a simple variable is still useful, or whether high-dimensional models on spatial lesion information are superior. METHODS We included 753 first-ever anterior circulation ischemic stroke patients (age 68.4±15.2 years; NIHSS at 24 h 4.4±5.1; modified Rankin Scale (mRS) at 3-months median[IQR] 1[0.75;3]) and traced lesions on diffusion-weighted MRI. In an out-of-sample model validation scheme, we predicted stroke severity as measured by NIHSS 24 h and functional stroke outcome as measured by mRS at 3 months either from spatial lesion features or lesion size. RESULTS For stroke severity, the best regression model based on lesion size performed significantly above chance (p < 0.0001) with R2 = 0.322, but models with spatial lesion features performed significantly better with R2 = 0.363 (t(752) = 2.889; p = 0.004). For stroke outcome, the best classification model based on lesion size again performed significantly above chance (p < 0.0001) with an accuracy of 62.8%, which was not different from the best model with spatial lesion features (62.6%, p = 0.80). With smaller training data sets of only 150 or 50 patients, the performance of high-dimensional models with spatial lesion features decreased up to the point of being equivalent or even inferior to models trained on lesion size. The combination of lesion size and spatial lesion features in one model did not improve predictions. CONCLUSIONS Lesion size is a decent biomarker for stroke outcome and severity that is slightly inferior to spatial lesion features but is particularly suited in studies with small samples. When low-dimensional models are desired, lesion size provides a viable proxy biomarker for spatial lesion features, whereas high-precision prediction models in personalised prognostic medicine should operate with high-dimensional spatial imaging features in large samples

    Pediatric Stroke: Clinical Findings and Radiological Approach

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    This paper focuses on radiological approach in pediatric stroke including both ischemic stroke (Arterial Ischemic Stroke and Cerebral Sinovenous Thrombosis) and hemorrhagic stroke. Etiopathology and main clinical findings are examined as well. Magnetic Resonance Imaging could be considered as the first-choice diagnostic exam, offering a complete diagnostic set of information both in the discrimination between ischemic/hemorrhagic stroke and in the identification of underlying causes. In addition, Magnetic Resonance vascular techniques supply further information about cerebral arterial and venous circulation. Computed Tomography, for its limits and radiation exposure, should be used only when Magnetic Resonance is not available and on unstable patients

    Patient with corticobasal syndrome showing disease-associated biomarkers of dementia with Lewy Bodies: a Treviso Dementia (TREDEM) registry case report

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    Background: An 82-year-old right-handed man, a retired teacher, reported the occurrence, three years earlier, of difficulties in moving his left arm and foot, tremor in his left hand, and gestures of the left upper limb that appeared to be independent of the patient's will.Objective: We describe an unusual case of corticobasal syndrome (CBS) showing disease-associated biomarkers of dementia with Lewy bodies (DLB).Methods: Clinical, neuropsychological, imaging, and biomarker evaluations were conducted, including tau and amyloid-beta levels in the cerebrospinal fluid (CSF) and a RT-QuIC assay for alpha-synuclein both in the CSF and olfactory mucosa (OM), as well as a QEEG assessment.Results: The patient presented resting tremor, mild extrapyramidal hypertonus, mild bradykinesia on the left side, and severe apraxia on the left upper limb. Brain MRI showed a diffuse right hemisphere atrophy which was prominent in the posterior parietal and temporal cortices, and moderate in the frontal cortex and the precuneus area. F-18-FDG PET imaging showed reduced glucose metabolism in the right lateral parietal, temporal, and frontal cortices with involvement of the right precuneus. The putamen did not appear to be pathological at DaTQUANT. Neuropsychological tests showed memory and visual-perceptual deficits. CSF tau and amyloid measurements did not show clear pathological values. RT-QuIC for alpha-synuclein in CSF and OM samples were positive. The QEEG analysis showed a pre-alpha dominant frequency in posterior derivations, typical of early stages of DLB.Conclusion: Although in the present patient the clinical diagnosis was of probable CBS, unexpectedly positive biomarkers for DLB suggested the co-presence of multiple pathologies

    Estrategia metodológica para establecer preferencias de pescadores marítimos deportivos tendientes a mejorar la calidad de la experiencia turística /

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    El presente artículo tiene como objetivo desarrollar un instrumento técnico metodológico que permita establecer preferencias del pescador marítimo deportivo en sus desplazamientos para la práctica de la actividad, de modo tal de generar una herramienta válida para la toma de decisiones en la gestión pública del turismo en espacios litorales a fin de mejorar la calidad de la experiencia turística. Es una investigación de carácter empírico con un enfoque mixto fundamentado en una estrategia cualitativa y cuantitativa. A través de la descomposición analítica del concepto medido, se facilita la identificación de los elementos intervinientes en el problema y de los atributos percibidos como relevantes para los pescadores, importante para orientar las acciones de política turística

    More atypical than atypical Alzheimer's disease phenotypes: a Treviso Dementia (TREDEM) registry case report

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    Background: A 57-year-old right-handed man was admitted to the Treviso Memory Clinic due to the presence of memory forgetfulness, repetition of the same questions, episodes of confusion, initial difficulties in performing complex tasks and easy distraction over the past two years, as well as recurrent and never-happened-before car accidents.Objective: We report a peculiar case of an early onset Alzheimer's disease (AD) with an unusual symptomatology, apparently not fitting in any of the categorized atypical forms of AD nor being representative of a typical amnestic AD.Methods: The patient underwent a neuropsychological, structural, and metabolic cerebral evaluation by MRI and F-18-FDG PET, together with the search for cerebral amyloid (amyloid PET), a genetic testing for dementia related genes and the dosage of CSF protein biomarkers of neurodegenerative conditions.Results: We observed a convergence of predominant frontal (dysexecutive, verbal disinhibition) and posterior (visuospatial) features of cognitive impairment. Structural MRI sequences showed subarachnoid spaces of the vault enlarged in the frontoparietal region with anterior and posterior cortical atrophy. The hippocampus appeared preserved. The 18F-FDG PET scans showed hypometabolism in the prefrontal, lateral temporal, posterior parietal, and occipital regions bilaterally. The F-18-Flutemetamol scan showed a diffused uptake of the amyloid tracer at the cerebral cortex. CSF biomarkers were compatible with Alzheimer's disease (AD).Conclusion: This case report presented with clinical phenotypic aspects atypical of AD, both frontal and posterior, never described as concomitant in the most accredited criteria for atypical AD, and appeared therefore more atypical than each of the atypical AD phenotypes already reported

    A typology of cerebral small vessel disease based on imaging markers.

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    BACKGROUND Lacunes, microbleeds, enlarged perivascular spaces (EPVS), and white matter hyperintensities (WMH) are brain imaging features of cerebral small vessel disease (SVD). Based on these imaging markers, we aimed to identify subtypes of SVD and to evaluate the validity of these markers as part of clinical ratings and as biomarkers for stroke outcome. METHODS In a cross-sectional study, we examined 1207 first-ever anterior circulation ischemic stroke patients (mean age 69.1 ± 15.4 years; mean NIHSS 5.3 ± 6.8). On acute stroke MRI, we assessed the numbers of lacunes and microbleeds and rated EPVS and deep and periventricular WMH. We used unsupervised learning to cluster patients based on these variables. RESULTS We identified five clusters, of which the last three appeared to represent distinct late stages of SVD. The two largest clusters had no to only mild or moderate WMH and EPVS, respectively, and favorable stroke outcome. The third cluster was characterized by the largest number of lacunes and a likewise favorable outcome. The fourth cluster had the highest age, most pronounced WMH, and poor outcome. Showing the worst outcome, the fifth cluster presented pronounced microbleeds and the most severe SVD burden. CONCLUSION The study confirmed the existence of different SVD types with different relationships to stroke outcome. EPVS and WMH were identified as imaging features of presumably early progression. The number of microbleeds and WMH severity appear to be promising biomarkers for distinguishing clinical subgroups. Further understanding of SVD progression might require consideration of refined SVD features, e.g., for EPVS and type of lacunes

    Comparison of intranasal versus intravenous midazolam for management of status epilepticus in dogs : a multi‐center randomized parallel group clinical study

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    Background: The intranasal (IN) route for rapid drug administration in patients with brain disorders, including status epilepticus, has been investigated. Status epilepticus is an emergency, and the IN route offers a valuable alternative to other routes, especially when these fail. Objectives: To compare IN versus IV midazolam (MDZ) at the same dosage (0.2 mg/kg) for controlling status epilepticus in dogs. Animals Client-owned dogs (n = 44) with idiopathic epilepsy, structural epilepsy, or epilepsy of unknown origin manifesting as status epilepticus. Methods: Randomized parallel group clinical trial. Patients were randomly allocated to the IN-MDZ (n = 21) or IV-MDZ (n = 23) group. Number of successfully treated cases (defined as seizure cessation within 5 minutes and lasting for >= 10 minutes), seizure cessation time, and adverse effects were recorded. Comparisons were performed using the Fisher's exact and Wilcoxon rank sum tests with statistical significance set at alpha < .05. Results: IN-MDZ and IV-MDZ successfully stopped status epilepticus in 76% and 61% of cases, respectively (P = .34). The median seizure cessation time was 33 and 64 seconds for IN-MDZ and IV-MDZ, respectively (P = .63). When the time to place an IV catheter was taken into account, IN-MDZ (100 seconds) was superior (P = .04) to IV-MDZ (270 seconds). Sedation and ataxia were seen in 88% and 79% of the dogs treated with IN-MDZ and IV-MDZ, respectively. Conclusions and Clinical Importance: Both routes are quick, safe, and effective for controlling status epilepticus. However, the IN route demonstrated superiority when the time needed to place an IV catheter was taken into account
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