Factors Affecting the Clinical Measurement of Visuo-Spatial Neglect

The present study examined a battery of tests to evaluate unilateral spatial neglect; the tests included different tasks involving several modalities of spatial exploration mapping perceptual, motor, attentional and personal or extrapersonal space dimensions. The subjects, 121 right-brain-damaged patients with unilateral neglect, were studied in seven laboratories in four European countries. Relationships among the various tests were examined by correlations, a cluster analysis and by an analysis of individual cases. Different sensitivity was found among various tests for detecting neglect performances. Both the cluster analysis and the single case analysis clearly showed a segregation between personal and extrapersonal neglect. Analysis of the large cluster, including a variety of tests of extra personal neglect, together with the study of single cases, suggests the possibility of differentiating the various manifestations of spatial neglect which can be interpreted on the basis of the descriptions of other individual cases previously reported in the literature. Finally, the present study indicated the relative stability of neglect following the acute phase and its independence from age

Factors Affecting the Clinical Measurement of Visuo-Spatial Neglect

The present study examined a battery of tests to evaluate unilateral spatial neglect; the tests included different tasks involving several modalities of spatial exploration mapping perceptual, motor, attentional and personal or extrapersonal space dimensions. The subjects, 121 right-brain-damaged patients with unilateral neglect, were studied in seven laboratories in four European countries. Relationships among the various tests were examined by correlations, a cluster analysis and by an analysis of individual cases. Different sensitivity was found among various tests for detecting neglect performances. Both the cluster analysis and the single case analysis clearly showed a segregation between personal and extrapersonal neglect. Analysis of the large cluster, including a variety of tests of extra personal neglect, together with the study of single cases, suggests the possibility of differentiating the various manifestations of spatial neglect which can be interpreted on the basis of the descriptions of other individual cases previously reported in the literature. Finally, the present study indicated the relative stability of neglect following the acute phase and its independence from age

The application of rules in morphology, syntax and number processing: a case of selective deficit of procedural or executive mechanisms?: Deficit of procedural or executive mechanisms

International audienceDeclarative memory is a long-term store for facts, concepts and words. Procedural memory subserves the learning and control of sensorimotor and cognitive skills, including the mental grammar. In this study, we report a single-case study of a mild aphasic patient who showed procedural deficits in the presence of preserved declarative memory abilities. We administered several experiments to explore rule application in morphology, syntax and number processing. Results partly support the differentiation between declarative and procedural memory. Moreover, the patient's performance varied according to the domain in which rules were to be applied, which underlines the need for more fine-grained distinctions in cognition between procedural rules

Using PET with 18F-AV-45 (florbetapir) to quantify brain amyloid load in a clinical environment

International audiencePURPOSE: Positron emission tomography (PET) imaging of brain amyloid load has been suggested as a core biomarker for Alzheimer's disease (AD). The aim of this study was to test the feasibility of using PET imaging with (18)F-AV-45 (florbetapir) in a routine clinical environment to differentiate between patients with mild to moderate AD and mild cognitive impairment (MCI) from normal healthy controls (HC). METHODS: In this study, 46 subjects (20 men and 26 women, mean age of 69.0 ± 7.6 years), including 13 with AD, 12 with MCI and 21 HC subjects, were enrolled from three academic memory clinics. PET images were acquired over a 10-min period 50 min after injection of florbetapir (mean ± SD of radioactivity injected, 259 ± 57 MBq). PET images were assessed visually by two individuals blinded to any clinical information and quantitatively via the standard uptake value ratio (SUVr) in the specific regions of interest, which were defined in relation to the cerebellum as the reference region. RESULTS: The mean values of SUVr were higher in AD patients (median 1.20, Q1-Q3 1.16-1.30) than in HC subjects (median 1.05, Q1-Q3 1.04-1.08; p = 0.0001) in the overall cortex and all cortical regions (precuneus, anterior and posterior cingulate, and frontal median, temporal, parietal and occipital cortex). The MCI subjects also showed a higher uptake of florbetapir in the posterior cingulate cortex (median 1.06, Q1-Q3 0.97-1.28) compared with HC subjects (median 0.95, Q1-Q3 0.82-1.02; p = 0.03). Qualitative visual assessment of the PET scans showed a sensitivity of 84.6% (95% CI 0.55-0.98) and a specificity of 38.1% (95% CI 0.18-0.62) for discriminating AD patients from HC subjects; however, the quantitative assessment of the global cortex SUVr showed a sensitivity of 92.3% and specificity of 90.5% with a cut-off value of 1.122 (area under the curve 0.894). CONCLUSION: These preliminary results suggest that PET with florbetapir is a safe and suitable biomarker for AD that can be used routinely in a clinical environment. However, the low specificity of the visual PET scan assessment could be improved by the use of specific training and automatic or semiautomatic quantification tools

Cada coisa em seu lugar: ensaio de interpretação do discurso de um museu de história

O Museu Histórico Nacional, situado no Rio de Janeiro, foi criado em 1922, como parte das comemorações do Centenário da Independência do Brasil. Ao longo dos seguintes 38 anos, foi dirigido por Gustavo Barroso. Este intelectual, figura bastante típica da “república das letras” brasileira, imprimiu no MHN uma forte marca pessoal, cristalizada no discurso conservador expresso pelas exposições. Baseado nas formulações teóricas de Carlo Ginzburg, conforme apresentadas em um artigo intitulado “Sinais - raízes de um paradigma indiciário”, bem como em diversos textos que abordam museus como discursos, o autor analisa a exposição do MHN nos anos 30, 40 e 50. Apoiando-se também na produção científica dos conservadores, publicada em livros e na revista institucional, os “Anais do Museu Histórico Nacional”, procura ver o circuito como representação das posições ocupadas pelos “agentes ativos da história” - aristocracia, funcionários públicos civis e militares, dentre outras categorias - em relação a uma categoria não claramente definida, o “povo”, que foi representada através da ausência

Some remarks on the chain segment dynamics in confined polymers

Recently, the chain dynamics of molten polymers in confined geometries has been investigated, using NMR. Some of these experiments have been performed on poydimethylsiloxane (PDMS) confined in planar nanolayers involving non-adsorbant solid surfaces. Here the data obtained on various PDMS systems are compared. The common property to these systems is that the local dynamics is anisotropic and the chain segments are undergoing uniaxial fluctuations around the normal $\overrightarrow{\rm n}$ to the layers. Our data clearly show that the sign of the degree of orientational order S (i.e. the direction of the fluctuations around $\overrightarrow{\rm n}$) and the broadening of the order distribution P(S) both result from the relative influence of the impenetrable interfaces and anchoring junctions on the segment behaviour