Clinical findings of equine leukoencephalomalacia / Achados clínicos de leucoencefalomalácia equina

Equine leukoencephalomalacia (LEM) is a disease caused by the ingestion of food, especially corn, contaminated by fumonisin, a Fusarium verticillioides (synonymous with F. moniliforme) metabolite. The clinical signs of brain injuries have an acute onset and rapid evolution. This study aimed to describe the clinical findings in 11 animals diagnosed with LEM, including cerebrospinal fluid (CSF) analysis. Of these animals, 91% (10/11) were horses, and only 9% (1/11) were asinine. The clinical localization of the lesions was 64% (7/10) cerebral, manifested mainly by altered mental state and behavioral disturbance, and 36% (4/11) were brainstem lesions, manifested by incoordination, head tilt, nystagmus, facial hypoalgesia, difficulty in apprehension, chewing, and swallowing food. Postmortem findings revealed that 82% (9/11) of the lesions were in the cerebrum and 18% (2/11) in the brainstem. CSF findings, such as xanthochromia (43%, 3/7), hyperproteinorrachia (50%, 3/6), and pleocytosis (43%, 3/7) were observed. The affected animals showed neurological signs that were compatible with cerebral and/or brainstem injuries. The CSF from animals with LEM may present with xanthochromia, hyperproteinorrachia, and pleocytosis, reinforcing the fact that this disease should be included in the differential diagnosis of encephalomyelopathies.(AU)

A leucoencefalomalácia (LEM) é uma enfermidade que acomete equídeos causada pela ingestão de milho e seus derivados e feno contaminados pela micotoxina fumonisina, um metabólito do fungo Fusarium verticillioides (sinônimo para F. moniliforme). Os sinais clínicos apresentam início agudo e evolução rápida e são decorrentes de lesões encefálicas. O objetivo deste estudo é descrever os achados clínicos de 11 equídeos diagnosticados com LEM, incluindo a análise do líquido cefalorraquidiano (LCR). 91% dos animais afetados eram equinos e somente 9% (1/11) era asinino. A localização clínica das lesões era 64% (7/10) cerebrais, manifestadas por alterações no estado mental e comportamento e 36% (4/10) no tronco encefálico, manifestadas por incoordenação, desvio lateral de cabeça, nistagmo, hipoalgesia da face e dificuldade de apreensão, mastigação e deglutição de alimentos. Comparativamente, os achados post mortem revelaram que 82% (9/11) das lesões eram no cérebro e 18% (2/11) no tronco encefálico. Alterações no LCR, tais como xantocromia (43%, 3/7), hiperproteinorraquia (50%, 3/6) e pleocitose (43%, 3/7), foram observadas. Os animais afetados apresentaram sinais clínicos compatíveis com lesões encefálicas e/ou de tronco cerebral. O LCR de animais com LEM pode apresentar xantocromia, hiperproteinorraquia, e pleocitose, reforçando que esta doença deve ser incluída como diagnóstico diferencial de encefalomielites.(AU)

Clinical findings of equine leukoencephalomalacia

ABSTRACT: Equine leukoencephalomalacia (LEM) is a disease caused by the ingestion of food, especially corn, contaminated by fumonisin, a Fusarium verticillioides (synonymous with F. moniliforme) metabolite. The clinical signs of brain injuries have an acute onset and rapid evolution. This study aimed to describe the clinical findings in 11 animals diagnosed with LEM, including cerebrospinal fluid (CSF) analysis. Of these animals, 91% (10/11) were horses, and only 9% (1/11) were asinine. The clinical localization of the lesions was 64% (7/10) cerebral, manifested mainly by altered mental state and behavioral disturbance, and 36% (4/11) were brainstem lesions, manifested by incoordination, head tilt, nystagmus, facial hypoalgesia, difficulty in apprehension, chewing, and swallowing food. Postmortem findings revealed that 82% (9/11) of the lesions were in the cerebrum and 18% (2/11) in the brainstem. CSF findings, such as xanthochromia (43%, 3/7), hyperproteinorrachia (50%, 3/6), and pleocytosis (43%, 3/7) were observed. The affected animals showed neurological signs that were compatible with cerebral and/or brainstem injuries. The CSF from animals with LEM may present with xanthochromia, hyperproteinorrachia, and pleocytosis, reinforcing the fact that this disease should be included in the differential diagnosis of encephalomyelopathies.

RESUMO: A leucoencefalomalácia (LEM) é uma enfermidade que acomete equídeos causada pela ingestão de milho e seus derivados e feno contaminados pela micotoxina fumonisina, um metabólito do fungo Fusarium verticillioides (sinônimo para F. moniliforme). Os sinais clínicos apresentam início agudo e evolução rápida e são decorrentes de lesões encefálicas. O objetivo deste estudo é descrever os achados clínicos de 11 equídeos diagnosticados com LEM, incluindo a análise do líquido cefalorraquidiano (LCR). 91% dos animais afetados eram equinos e somente 9% (1/11) era asinino. A localização clínica das lesões era 64% (7/10) cerebrais, manifestadas por alterações no estado mental e comportamento e 36% (4/10) no tronco encefálico, manifestadas por incoordenação, desvio lateral de cabeça, nistagmo, hipoalgesia da face e dificuldade de apreensão, mastigação e deglutição de alimentos. Comparativamente, os achados post mortem revelaram que 82% (9/11) das lesões eram no cérebro e 18% (2/11) no tronco encefálico. Alterações no LCR, tais como xantocromia (43%, 3/7), hiperproteinorraquia (50%, 3/6) e pleocitose (43%, 3/7), foram observadas. Os animais afetados apresentaram sinais clínicos compatíveis com lesões encefálicas e/ou de tronco cerebral. O LCR de animais com LEM pode apresentar xantocromia, hiperproteinorraquia, e pleocitose, reforçando que esta doença deve ser incluída como diagnóstico diferencial de encefalomielites.

Theory of mind complex task: validity based on relationships with external variables / Tarefa complexa de teoria da mente: validade baseada nas relações com variáveis externas / Tarea compleja de la teoría de la mente: validez basada en relaciones con variables externas

Most research on Theory of Mind (ToM) focuses on preschool years, with few studies targeting later years, especially in the national context. This study aimed to investigate evidence of the validity of a Theory of Mind Complex Task from the relationship with the external variables: age, type of school, and vocabulary. Ninety-eight children, aged between 6 and 9, from private and public schools participated. Results showed age and school effect, with better performance of children from private schools. There was a positive, significant, and moderate magnitude correlation with vocabulary. This study provides the first sources of evidence of task validity, indicating that age and type of school were relevant variables for ToM performance, and therefore should be considered in the elaboration of future norms.

A maior parte das pesquisas sobre a teoria da mente (ToM) concentra-se nos anos pré-escolares, sendo poucos os estudos direcionados aos anos posteriores, principalmente em contexto nacional. O objetivo deste estudo foi investigar evidências de validade de uma tarefa complexa de ToM a partir da relação com variáveis externas: idade, tipo de escola e vocabulário. Participaram 98 crianças, entre 6 e 9 anos de idade, de escolas privadas e públicas. Os resultados obtidos mostraram efeito de idade e de escola, com melhor desempenho das crianças de escolas privadas. Houve correlação positiva, significativa e de magnitude moderada com vocabulário. Este estudo disponibiliza as primeiras fontes de evidências de validade da tarefa, indicando que idade e tipo de escola se mostraram variáveis relevantes para o desempenho em ToM, as quais, por isso, devem ser consideradas na elaboração de normas futuras.

Las investigaciones sobre la teoría de la mente (ToM) se centra en los años preescolares, especialmente en el contexto nacional. El objetivo de este estudio fue investigar la evidencia de la validez de una tarea compleja de la ToM a partir de la relación con variables externas: edad, tipo de escuela y vocabulario. Participaron 98 niños, de edades comprendidas entre 6 y 9 años, de escuelas privadas y públicas. Los resultados mostraron efecto de la edad y escolar, con un mejor desempeño de los niños de escuelas privadas. Hubo una correlación de magnitud moderada, positiva y significativa con el vocabulario. Este estudio proporciona las primeras fuentes de evidencia de la validez de la tarea, indicando que la edad y el tipo de escuela son variables relevantes para el desempeño de la ToM y, por lo tanto, deberían considerarse en la elaboración de normas futuras.

Component mechanisms of executive function in schizophrenia and their contribution to functional outcomes

Objective: In schizophrenia, scores reflecting deficits in different cognitive processes are strongly correlated, making it difficult to establish a solid relationship between different cognitive mechanisms and other features of this disorder. The objective of this study was to explore whether three frequently postulated executive functions (updating, shifting, and inhibition) could be compared between groups and considered independently in terms of their respective roles in functional outcome. Methods: This study relied on confirmatory factor analysis of schizophrenia patients (n=141) and healthy controls (n=119). The main analyses examined the degree to which three executive functions (updating, set-shifting, and inhibition) could be separated in schizophrenia and compared this model among groups. Structural equation modeling analysis was also performed to examine the extent to which executive function components contribute to functional outcome in schizophrenia. Results: Multiple-group confirmatory factor analysis with unconstrained model parameters indicated that the full three-factor model may fit the data in both groups (χ2 = 61.48, degrees of freedom = 34, p < 0.001, comparative fit index = 0.95; standardized root mean square residual = 0.037; root mean square error of approximation = 0.04; Akaike's information criteria = 169.49; normed fit index = 0.90), although there was also a good data fit for the patient group with a two-factor model. In the patient group, structural equation modeling suggested that shifting and (principally) updating were associated with the general measure of functional outcome (regression path coefficients: 0.34, p < 0.005; 0.39, p < 0.005, respectively), although when combined the mechanisms fail to contribute. Conclusion: This data suggests that the factor structure may be similar but not identical between groups, and both updating and shifting may play an important role in functional outcome in schizophrenia.

Component mechanisms of executive function in schizophrenia and their contribution to functional outcomes.

OBJECTIVE: In schizophrenia, scores reflecting deficits in different cognitive processes are strongly correlated, making it difficult to establish a solid relationship between different cognitive mechanisms and other features of this disorder. The objective of this study was to explore whether three frequently postulated executive functions (updating, shifting, and inhibition) could be compared between groups and considered independently in terms of their respective roles in functional outcome. METHODS: This study relied on confirmatory factor analysis of schizophrenia patients (n=141) and healthy controls (n=119). The main analyses examined the degree to which three executive functions (updating, set-shifting, and inhibition) could be separated in schizophrenia and compared this model among groups. Structural equation modeling analysis was also performed to examine the extent to which executive function components contribute to functional outcome in schizophrenia. RESULTS: Multiple-group confirmatory factor analysis with unconstrained model parameters indicated that the full three-factor model may fit the data in both groups (χ2 = 61.48, degrees of freedom = 34, p < 0.001, comparative fit index = 0.95; standardized root mean square residual = 0.037; root mean square error of approximation = 0.04; Akaike's information criteria = 169.49; normed fit index = 0.90), although there was also a good data fit for the patient group with a two-factor model. In the patient group, structural equation modeling suggested that shifting and (principally) updating were associated with the general measure of functional outcome (regression path coefficients: 0.34, p < 0.005; 0.39, p < 0.005, respectively), although when combined the mechanisms fail to contribute. CONCLUSION: This data suggests that the factor structure may be similar but not identical between groups, and both updating and shifting may play an important role in functional outcome in schizophrenia.

Contribution of Word Reading Speed to Reading Comprehension in Brazilian Children: Does Speed Matter to the Comprehension Model?

Studies have suggested that reading speed (RS) or fluency should be a component of reading comprehension (RC) models. There is also evidence of a relationship between RS and RC. However, some questions remain to be explored, as the changes in such a relationship may be a function of development. In addition, while there are studies published with English speakers and learners, less evidence exists in more transparent orthographies, such as Portuguese. This study investigated the relationship between RC and RS in typical readers. Objectives included elucidating the following: (1) the contribution of RS to RC controlling for intelligence, word recognition, and listening and (2) the differential relationships and contributions of RS to comprehension in different school grades. The sample of participants comprised 212 students (M = 8.76; SD = 1.06) from 2nd to 4th grade. We assessed intelligence, word recognition, word RS, listening, and RC. Performance in all tests increased as a function of grade. There were significant connections between RC and all other measures. Nonetheless, the regression analysis revealed that word RS has a unique contribution to RC after controlling for intelligence, word recognition, and listening, with a very modest but significant improvement in the explanatory power of the model. We found a significant relationship between RS and RC only for 4th grade and such relationship becomes marginal after controlling for word recognition. The findings suggest that RS could contribute to RC in Portuguese beyond the variance shared with listening and, mainly, word recognition, but such a contribution was very small. The data also reveal a differential relationship between RS and RC in different school grades; specifically, only for the 4th grade does RS begins to relate to RC. The findings add a developmental perspective to the study of reading models.

Investigation of cognition in schizophrenia: psychometric properties of instruments for assessing working memory updating / Investigação da cognição na esquizofrenia: propriedades psicométricas de instrumentos para avaliação de atualização da memória de trabalho

Objective This study describes the development of two updating measures of working memory (WM): Letter Updating Test (LUT) and Word Updating Test (WUT). Methods In stage 1, items were created and the instruments were assessed by experts and laymen. In stage 2, tests were given to 15 patients with schizophrenia and 15 paired controls. All were able to understand and respond to the instruments. In stage 3, 141 patients with schizophrenia and 119 healthy controls aged 18 to 60 took part; they were assessed on WM, processing speed (PS) and functional outcome. Results The results showed adequate rates of internal consistency for both measures developed, for both the total sample and each group separately, as well as evidence of convergent validity, discriminant validity and sensitivity to differentiate performance among the groups. Principal component analysis yielded two components, one for updating tests and other for PS measures, indicating factorial validity. Positive and significant, yet low, correlations were found with functionality measures. Conclusion These results provide adequate psychometric parameters for the measures developed, applicable to cognitive research settings in schizophrenia.

Objetivo O estudo descreve o desenvolvimento de duas medidas de atualização da memória de trabalho (MT): Teste de Atualização de Letras (TAL) e Teste de Atualização de Palavras (TAP). Métodos Na etapa 1 foram criados itens e os instrumentos foram analisados por experts e leigos. Na etapa 2, os testes foram aplicados em 15 pacientes com esquizofrenia e 15 controles pareados. Todos foram capazes de compreender e responder aos instrumentos. Na etapa 3, participaram 141 pacientes com esquizofrenia e 119 controles saudáveis com idades entre 18 e 60 anos, avaliados em MT, velocidade de processamento (VP) e funcionalidade. Resultados Os resultados revelaram bons índices de consistência interna para ambas as medidas desenvolvidas, tanto para a amostra total como para cada grupo separadamente, bem como evidências de validade convergente com medidas de MT, validade discriminante com medidas de VP e sensibilidade para discriminar o desempenho entre os grupos. Análise de componentes principais revelou que os testes de atualização apresentaram altas cargas e um fator separado das medidas de VP. Relações positivas, significativas, porém baixas, foram encontradas com medidas de funcionalidade. Conclusão Esses resultados fornecem bons parâmetros psicométricos para as medidas desenvolvidas, aplicáveis em contextos de pesquisa cognitiva da esquizofrenia.

Reading component skills in dyslexia: word recognition, comprehension and processing speed.

The cognitive model of reading comprehension (RC) posits that RC is a result of the interaction between decoding and linguistic comprehension. Recently, the notion of decoding skill was expanded to include word recognition. In addition, some studies suggest that other skills could be integrated into this model, like processing speed, and have consistently indicated that this skill influences and is an important predictor of the main components of the model, such as vocabulary for comprehension and phonological awareness of word recognition. The following study evaluated the components of the RC model and predictive skills in children and adolescents with dyslexia. 40 children and adolescents (8-13 years) were divided in a Dyslexic Group (DG; 18 children, MA = 10.78, SD = 1.66) and control group (CG 22 children, MA = 10.59, SD = 1.86). All were students from the 2nd to 8th grade of elementary school and groups were equivalent in school grade, age, gender, and IQ. Oral and RC, word recognition, processing speed, picture naming, receptive vocabulary, and phonological awareness were assessed. There were no group differences regarding the accuracy in oral and RC, phonological awareness, naming, and vocabulary scores. DG performed worse than the CG in word recognition (general score and orthographic confusion items) and were slower in naming. Results corroborated the literature regarding word recognition and processing speed deficits in dyslexia. However, dyslexics can achieve normal scores on RC test. Data supports the importance of delimitation of different reading strategies embedded in the word recognition component. The role of processing speed in reading problems remain unclear.