6 research outputs found

    Differential prefrontal-like deficit in children after cerebellar astrocytoma and medulloblastoma tumor

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    Background: This study was realized thanks to the collaboration of children and adolescents who had been resected from cerebellar tumors. The medulloblastoma group (CE+, n = 7) in addition to surgery received radiation and chemotherapy. The astrocytoma group (CE, n = 13) did not receive additional treatments. Each clinical group was compared in their executive functioning with a paired control group (n = 12). The performances of the clinical groups with respect to controls were compared considering the tumor's localization (vermis or hemisphere) and the affectation (or not) of the dentate nucleus. Executive variables were correlated with the age at surgery, the time between surgery-evaluation and the resected volume. Methods: The executive functioning was assessed by means of WCST, Complex Rey Figure, Controlled Oral Word Association Test (letter and animal categories), Digits span (WISC-R verbal scale) and Stroop test. These tests are very sensitive to dorsolateral PFC and/or to medial frontal cortex functions. The scores for the non-verbal Raven IQ were also obtained. Direct scores were corrected by age and transformed in standard scores using normative data. The neuropsychological evaluation was made at 3.25 (SD = 2.74) years from surgery in CE group and at 6.47 (SD = 2.77) in CE+ group. Results: The Medulloblastoma group showed severe executive deficit (</= 1.5 SD below normal mean) in all assessed tests, the most severe occurring in vermal patients. The Astrocytoma group also showed executive deficits in digits span, semantic fluency (animal category) and moderate to slight deficit in Stroop (word and colour) tests. In the astrocytoma group, the tumor's localization and dentate affectation showed different profile and level of impairment: moderate to slight for vermal and hemispheric patients respectively. The resected volume, age at surgery and the time between surgery-evaluation correlated with some neuropsychological executive variables. Conclusion: Results suggest a differential prefrontal-like deficit due to cerebellar lesions and/or cerebellar-frontal diaschisis, as indicate the results in astrocytoma group (without treatments), that also can be generated and/or increased by treatments in the medulloblastoma group. The need for differential rehabilitation strategies for specific clinical groups is remarked. The results are also discussed in the context of the Cerebellar Cognitive Affective Syndrome.4:18; pags: 1-16 doi: 10.1186/1744-9081-4-18

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    Alternate response preparation in a visuomotor serial task

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    The preparation of a particular motor pattern is related to the information available that enables the actor to predict the correct response to a forthcoming stimulus. In many situations, however, prediction is not possible. In such cases, the individual can guess the probable parameters of the next stimulus. The authors attempted to establish the bias in the motor intention for movement and its interaction with a possible memory trace of the stimulus-response mapping produced by the preceding stimulus. Two letters were presented bilaterally, and participants (N=21) had to discriminate the target letter and respond with the compatible hand. The present findings support the existence of a memory trace of the previous stimulus-response mapping.37(2):127-34. doi: 10.3200/JMBR.37.2.127-13

    Potenciales evocados cognitivos en pacientes con esclerosis múltiple remitente-recurrente y benigna

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    Introducción: Conseguir una evaluación mejor del deterioro cognitivo en la esclerosis múltiple es uno de los grandes retos actuales. Un objetivo esencial es obtener, desde diferentes aproximaciones, la valoración objetiva del déficit, y que permitan su correlación con variables fisiológicas. Objetivos: Analizar las posibles modulaciones en componentes fisiológicos del procesamiento de la información relacionados con un déficit atencional en pacientes con diversos tipos de esclerosis múltiple. Sujetos y métodos: Participaron en el presente estudio 17 pacientes con esclerosis múltiple remitente-recurrente, nueve pacientes con esclerosis múltiple benigna y 19 sujetos sanos. Se registraron sus respuestas conductuales en una tarea visuoespacial y, posteriormente, se realizó una prueba oddball auditiva en la que se registró la señal de electroencefalografía para la obtención de los potenciales evocados cognitivos. Se realizaron, asimismo, análisis de correlación entre las variables fisiológicas con variables clínicas propias del paciente. Resultados: Se encontraron un retraso en los tiempos de reacción durante el desarrollo de la tarea de Posner y un retraso en la latencia del componente P3 durante la realización de la tarea oddball en ambos grupos de pacientes con esclerosis múltiple. Conclusión: Los resultados obtenidos en este experimento confirman la presencia de deterioro atencional en ambos grupos de pacientes. La modulación exclusiva de la latencia del componente P3 sugiere que el deterioro atencional en estos pacientes al comienzo de la enfermedad se localiza en el procesamiento cognitivo central y, en principio, es producto de la desmielinización.48(9):453-8
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