38 research outputs found

    Polarity-Dependent Misperception of Subjective Visual Vertical during and after Transcranial Direct Current Stimulation (tDCS)

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    Pathologic tilt of subjective visual vertical (SVV) frequently has adverse functional consequences for patients with stroke and vestibular disorders. Repetitive transcranial magnetic stimulation (rTMS) of the supramarginal gyrus can produce a transitory tilt on SVV in healthy subjects. However, the effect of transcranial direct current stimulation (tDCS) on SVV has never been systematically studied. We investigated whether bilateral tDCS over the temporal- parietal region could result in both online and offline SVV misperception in healthy subjects. In a randomized, sham-controlled, single-blind crossover pilot study, thirteen healthy subjects performed tests of SVV before, during and after the tDCS applied over the temporal- parietal region in three conditions used on different days: right anode/left cathode; right cathode/left anode; and sham. Subjects were blind to the tDCS conditions. Montage-specific current flow patterns were investigated using computational models. SVV was significantly displaced towards the anode during both active stimulation conditions when compared to sham condition. Immediately after both active conditions, there were rebound effects. Longer lasting after-effects towards the anode occurred only in the right cathode/left anode condition. Current flow models predicted the stimulation of temporal-parietal regions under the electrodes and deep clusters in the posterior limb of the internal capsule. The present findings indicate that tDCS over the temporal-parietal region can significantly alter human SVV perception. This tDCS approach may be a potential clinical tool for the treatment of SVV misperception in neurological patients

    Accuracy of mucocutaneous leishmaniasis diagnosis using polymerase chain reaction : systematic literature review and meta-analysis

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    The diagnosis of mucocutaneous leishmaniasis (MCL) is hampered by the absence of a gold standard. An accurate diagnosis is essential because of the high toxicity of the medications for the disease. This study aimed to assess the ability of polymerase chain reaction (PCR) to identify MCL and to compare these results with clinical research recently published by the authors. A systematic literature review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses: the PRISMA Statement was performed using comprehensive search criteria and communication with the authors. A meta-analysis considering the estimates of the univariate and bivariate models was performed. Specificity near 100% was common among the papers. The primary reason for accuracy differences was sensitivity. The meta-analysis, which was only possible for PCR samples of lesion fragments, revealed a sensitivity of 71% [95% confidence interval (CI) = 0.59; 0.81] and a specificity of 93% (95% CI = 0.83; 0.98) in the bivariate model. The search for measures that could increase the sensitivity of PCR should be encouraged. The quality of the collected material and the optimisation of the amplification of genetic material should be prioritised

    Bayesian methods in meta-analysis: specication of prior distributions for the between-studies variability

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    MAZIN, S. C.Metodos Bayesianos em Metanalise: Especicac~ao da Distribuic~ao a Priori para a Variabilidade entre os Estudos. 2009. 175f. Dissertac~ao (mestrado) - Faculdade de Medicina de Ribeir~ao Preto, Universidade de S~ao Paulo, Ribeir~ao Preto, 2009. Prossionais da saude, pesquisadores e outros responsaveis por polticas de saude s~ao frequentemente inundados com quantidades de informac~oes nem sempre manejaveis, o que torna a revis~ao sistematica uma maneira eciente de integrar o conhecimento existente gerando dados que auxiliem a tomada de decis~ao. Em uma revis~ao sistematica os dados dos diferentes estudos podem ser quantitativamente combinados por metodos estatsticos chamados metanalise. A metanalise e uma ferramenta estatstica utilizada para combinar ou integrar os resultados dos diversos estudos independentes, sobre o mesmo tema. Entre os estudos que comp~oem a metanalise pode existir uma variabilidade que n~ao e devida ao acaso, chamada heterogeneidade. A heterogeneidade e geralmente testada pelo teste Q ou quanticada pela estatstica I2. A investigac~ao da heterogeneidade na metanalise e de grande import^ancia pois a aus^encia ou a presenca indica o modelo estatstico mais adequado. Assim, na aus^encia desta variabilidade utilizamos um modelo estatstico de efeito xo e na presenca utilizamos um modelo de efeitos aleatorios que incorpora a variabilidade entre os estudos na metanalise. Muitas metanalises s~ao compostas por poucos estudos, e quando isso acontece, temos diculdades de estimar as medidas de efeito metanalticas atraves da teoria classica, pois esta e dependente de pressupostos assintoticos. Na abordagem bayesiana n~ao temos esse problema, mas devemos ter muito cuidado com a especicac~ao da distribuic~ao a priori. Uma vantagem da infer^encia bayesiana e a possibilidade de predizer um resultado para um estudo futuro. Neste trabalho, conduzimos um estudo sobre a especicac~ao da distribuic~ao a priori para o par^ametro que expressa a vari^ancia entre os estudos e constatamos que n~ao existe uma unica escolha que caracterize uma distribuic~ao a priori que possa ser considerada ~ao informativa\"em todas as situac~oes. A escolha de uma distribuic~ao a priori ~ao informativa\"depende da heterogeneidade entre os estudos na metanalise. Assim a distribuic~ao a priori deve ser escolhida com muito cuidado e seguida de uma analise de sensibilidade, especialmente quando o numero de estudos e pequeno.MAZIN, S. C. Bayesian methods in meta-analysis: specication of prior distributions for the between-studies variability. 2009. 175s. Dissertation (master degree) - Faculty of Medicine of Ribeir~ao Preto, University of S~ao Paulo, Ribeir~ao Preto, 2009. Health professionals, researchers and others responsible for health policy are often overwhelmed by amounts of information that can not always be manageable, which makes the systematic review an ecient way to integrate existing knowledge generating information that may help decision making. In a systematic review, data from dierent studies can be quantitatively combined by statistical methods called meta-analysis. The meta-analysis is a statistical tool used to combine or integrate the results of several independent studies on the same topic. Among the studies that comprise the meta-analysis we have a variability that does not yield from the chance, called the heterogeneity. Heterogeneity is usually tested by Q or quantied by the statistic I2. The investigation of heterogeneity in meta-analysis has a great importance because the absence or presence indicates the most appropriate statistical model. In the absence of this variability we used a xed eect statistical model and a random eects model was used to incorporate the variability between studies in the meta-analysis. Many meta-analysis are composed of few studies, and in those cases, it is dicult to estimate the eect of meta-analytic measures by the classical theory because the asymptotic assumptions. In the Bayesian approach we do not have this problem, but we must be very careful about the specication of prior distribution. One advantage of Bayesian inference is the ability to predict an outcome for a future study. In this work, carried out a study about the specication of prior distribution for the parameter that expresses of the variance between studies and found that there is no single choice that features a prior distribution that would be considered uninformative at all times. The choice of a prior distribution uninformative depend heterogeneity among studies in the meta-analysis. Thus, the prior distribution should be examined very carefully and followed by a sensitivity analysis, especially when the number of studies is small

    Questionário de Avaliação da Sobrecarga do Cuidador Informal: validação para o Brasil

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    RESUMOObjetivo:analisar a dimensionalidade, validade de constructo convergente e consistência interna do Questionário de Avaliação da Sobrecarga do Cuidador Informal (QASCI) após sua adaptação semântica para o Brasil.Método:este estudo metodológico foi realizado com 132 cuidadores informais de idosos com dependência nas atividades básicas ou instrumentais de vida diária, em uma capital do Nordeste. Para análise da validade de constructo convergente do QASCI foram utilizadas medidas de qualidade de vida relacionada à saúde, ansiedade e depressão.Resultados:no geral, os resultados da validação de constructo do instrumento evidenciaram correlações estatisticamente significantes com as três medidas. A análise fatorial confirmatória evidenciou um bom ajuste do modelo teórico de sete fatores (domínios) da versão utilizada no grupo estudado. O alfa de Cronbach para o total da escala foi 0,92.Conclusão:a versão brasileira do QASCI mostrou-se válida e confiável na mensuração da sobrecarga de cuidadores informais de idosos

    Normative data for human postural vertical: A systematic review and meta-analysis.

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    Perception of verticality is required for normal daily function, yet the typical human detection error range has not been well characterized. Vertical misperception has been correlated with poor postural control and functionality in patients after stroke and after vestibular disorders. Until now, all the published studies that assessed Subjective Postural Vertical (SPV) in the seated position used small groups to establish a reference value. However, this sample size does not represent the healthy population for comparison with conditions resulting in pathological vertical. Therefore, the primary objective was to conduct a systematic review with meta-analyses of Subjective Postural Vertical (SPV) data in seated position in healthy adults to establish the reference value with a representative sample. The secondary objective was to investigate the methodological characteristics of different assessment protocols of SPV described in the literature. A systematic literature search was conducted using Medline, EMBASE, and Cochrane libraries. Mean and standard deviation of SPV in frontal and sagittal planes were considered as effect size measures. Sixteen of 129 identified studies met eligibility criteria for our systematic review (n = 337 subjects in the frontal plane; n = 187 subjects in sagittal plane). The meta-analyses measure was estimated using the pooled mean as the estimator and its respective error. Mean reference values were 0.12°±1.49° for the frontal plane and 0.02°±1.82° for the sagittal plane. There was a small variability of the results and this systematic review resulted in representative values for SPV. The critical analysis of the studies and observed homogeneity in the sample suggests that the methodological differences used in the studies did not influence SPV assessment of directional bias in healthy subjects. These data can serve as a reference for clinical studies in disorders of verticality

    Survival after radiation therapy for high-grade glioma

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    BackgroundHigh-grade gliomas (HGGs) are a heterogeneous disease group, with variable prognosis, inevitably causing deterioration of the quality of life. The estimated 2-year overall survival is 20%, despite the best trimodality treatment consisting of surgery, chemotherapy, and radiotherapy.AimTo evaluate long-term survival outcomes and factors influencing the survival of patients with high-grade gliomas treated with radiotherapy.Materials and methodsData from 47 patients diagnosed with high-grade gliomas between 2009 and 2014 and treated with three-dimensional radiotherapy (3DRT) or intensity-modulated radiotherapy (IMRT) were analyzed retrospectively.ResultsMedian survival was 16.6 months; 29 patients (62%) died before the time of analysis. IMRT was employed in 68% of cases. The mean duration of radiotherapy was 56 days, and the mean delay to the start of radiotherapy was 61.7 days (range, 27–123 days). There were no statistically significant effects of duration of radiotherapy or delay to the start of radiotherapy on patient outcomes.ConclusionsAge, total amount of gross resection, histological type, and use of adjuvant temozolomide influenced survival rate (

    Intravenous rtPA versus mechanical thrombectomy in acute ischemic stroke: A historical cohort in Joinville, Brazil

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    Groundbreaking results concerning ischemic stroke (IS) hyperacute treatment worldwide were published in 2014 and 2015. We aimed to compare functional status after 3 months in patients treated with intra-arterial thrombectomy (IAT) and those treated with intravenous thrombolysis (IVT) alone in Joinville, Brazil.From the Joinville Stroke Registry, we extracted and compared all consecutive IVT patients treated with r-tPA within 4.5 h in the period 2009–2011 versus all consecutive IAT treated within 6 h with the Solitaire FR device plus IVT in the period 2012–2014.We registered 82 patients in the IVT group and 31 patients in the IAT group. At hospital admission, patients in the IAT group were significantly younger (p < 0.001), had a higher educational level (p = 0.001), had a slightly higher prevalence of atrial fibrillation (p = 0.057) and had more severe strokes measured by the NIH stroke scale (p = 0.011). After 90 days, 45% of patients in the IAT group and 27% in the IVT group were independent (0–1 points) according to the modified Rankin scale (adjusted odds ratio: 4.53; 95% CI: 1.22 to 16.75). Symptomatic hemorrhage was diagnosed in 10% of patients in both groups (p = 1.0). The 90-day case-fatality was 39% (32/82) in the IVT group and 26% (8/31) in the IAT group (p = 0.27). In this small cohort, a greater rate of functional independence was achieved in patients treated with IAT plus IVT, compared with patients treated with IVT lysis alone. Our “real-world” findings are consistent with results of controlled, randomized clinical trials. Keywords: Ischemic stroke, Stroke thrombolysis, Mechanical thrombectomy, Cohor
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