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Neuro-axonal degeneration occurs progressively from the onset of multiple sclerosis and is thought to be a significant cause of increasing clinical disability. Several histopathological studies of multiple sclerosis and experiment...
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Neuro-axonal degeneration occurs progressively from the onset of multiple sclerosis and is thought to be a significant cause of increasing clinical disability. Several histopathological studies of multiple sclerosis and experimental autoimmune encephalomyelitis have shown that the accumulation of sodium in axons can promote reverse action of the sodium/calcium exchanger that, in turn, leads to a lethal overload in intra-axonal calcium. We hypothesized that sodium magnetic resonance imaging would provide an indicator of cellular and metabolic integrity and ion homeostasis in patients with multiple sclerosis. Using a three-dimensional radial gradient-echo sequence with short echo time, we performed sodium magnetic resonance imaging at 3T in 17 patients with relapsing-remitting multiple sclerosis and in 13 normal subjects. The absolute total tissue sodium concentration was measured in lesions and in several areas of normal-appearing white and grey matter in patients, and corresponding areas of white and grey matter in controls. A mixed model analysis of covariance was performed to compare regional tissue sodium concentration levels in patients and controls. Spearman correlations were used to determine the association of regional tissue sodium concentration levels in T_2- and T_1-weighted lesions with measures of normalized whole brain and grey and white matter volumes, and with expanded disability status scale scores. In patients, tissue sodium concentration levels were found to be elevated in acute and chronic lesions compared to areas of normal-appearing white matter (P<0.0001). The tissue sodium concentration levels in areas of normal-appearing white matter were significantly higher than those in corresponding white matter regions in healthy controls (p<0.0001). The tissue sodium concentration value averaged over lesions and over regions of normal-appearing white and grey matter was positively associated with T_2-weighted (P收起
摘要 :
Neuro-axonal degeneration occurs progressively from the onset of multiple sclerosis and is thought to be a significant cause of increasing clinical disability. Several histopathological studies of multiple sclerosis and experiment...
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Neuro-axonal degeneration occurs progressively from the onset of multiple sclerosis and is thought to be a significant cause of increasing clinical disability. Several histopathological studies of multiple sclerosis and experimental autoimmune encephalomyelitis have shown that the accumulation of sodium in axons can promote reverse action of the sodium/calcium exchanger that, in turn, leads to a lethal overload in intra-axonal calcium. We hypothesized that sodium magnetic resonance imaging would provide an indicator of cellular and metabolic integrity and ion homeostasis in patients with multiple sclerosis. Using a three-dimensional radial gradient-echo sequence with short echo time, we performed sodium magnetic resonance imaging at 3T in 17 patients with relapsing-remitting multiple sclerosis and in 13 normal subjects. The absolute total tissue sodium concentration was measured in lesions and in several areas of normal-appearing white and grey matter in patients, and corresponding areas of white and grey matter in controls. A mixed model analysis of covariance was performed to compare regional tissue sodium concentration levels in patients and controls. Spearman correlations were used to determine the association of regional tissue sodium concentration levels in T_2- and T_1-weighted lesions with measures of normalized whole brain and grey and white matter volumes, and with expanded disability status scale scores. In patients, tissue sodium concentration levels were found to be elevated in acute and chronic lesions compared to areas of normal-appearing white matter (P<0.0001). The tissue sodium concentration levels in areas of normal-appearing white matter were significantly higher than those in corresponding white matter regions in healthy controls (p<0.0001). The tissue sodium concentration value averaged over lesions and over regions of normal-appearing white and grey matter was positively associated with T_2-weighted (P收起
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A growing body of research suggests that certain long-latency cognitive-related components of the event-related potential (ERP), in particular the auditory P3(00) and the mismatch negativity (MMN), can offer a valuable adjunct to ...
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A growing body of research suggests that certain long-latency cognitive-related components of the event-related potential (ERP), in particular the auditory P3(00) and the mismatch negativity (MMN), can offer a valuable adjunct to routine clinical examination and neurophysiologic methods in the early assessment and prediction of neurological outcome of comatose states. While certain clinical neurological signs (e.g., absent pupillary light reflexes) and ongoing EEG patterns (e.g., electrocerebral inactivity, burst suppression), as well as abnormality of short-latency sensory-evoked components (e.g., bilateral absence of the N20 somatosen-sory-evoked potential), are well established as early prognostic markers of poor coma outcome (i.e., persistent vegetative state or death) (Wijdicks et al., 2006; Zandbergen et al., 1998), the presence of cognitive-related components has been shown to predict the recovery of consciousness in patients who survive their coma (Dal-trozzo et al., 2007; Fischer et al., 1999;Gott et al., 1991; Kane et al., 1993; Signorino et al., 1995). Indeed, in contrast to standard clinical examination and measurement of short-latency sensory-evoked potentials, the late cognitive-related components enable the assessment of residual higher brain and cognitive functions, such as perception, attention, and memory, which may be more closely linked to the comatose patient's capability to regain consciousness.
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The school nurse has broad competencies regarding the improvement of the health of the educational community. However, in Spain it has low implementation and visibility. The development of nursing research allows us to provide sci...
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The school nurse has broad competencies regarding the improvement of the health of the educational community. However, in Spain it has low implementation and visibility. The development of nursing research allows us to provide scientific evidence that shows the importance it has in improving the quality of life of students and their families. Therefore, the objective has been to know the state of research in Spain, from the study of associations and working groups. The results show that the national panorama is very plural and diverse. There are associations in four communities and working groups in nine provinces. Therefore, continuity in research in school nursing and in the creation of work groups is necessary, since its objective is to implement this figure in their corresponding autonomous communities.
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On the assumption that linguistic faculties reflect both lexical storage in the temporal cortex and combinatorial rules in the striatal circuits, several authors have shown that striatal-damaged patients are impaired with conjugat...
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On the assumption that linguistic faculties reflect both lexical storage in the temporal cortex and combinatorial rules in the striatal circuits, several authors have shown that striatal-damaged patients are impaired with conjugation rules while retaining lexical knowledge of irregular verbs [Teichmann, M., Dupoux, E., Kouider, S., Brugieres, P., Boisse, M. F., Baudic, S., Cesaro, P., Peschanski, M., & Bachoud-Levi, A. C. (2005). The role of the striatum in rule application. The model of Huntington's disease at early stage. Brain, 128, 1155-1167; Ullman, M. T., Corkin, S., Coppola, M., Hickok, G., Growdon, J. H., Koroshetz, W. J., & Pinker, S. (1997). A neural dissociation within language: Evidence that the mental dictionary is part of declarative memory, and that grammatical rules are processed by the procedural system. Journal of Cognitive Neuroscience, 9, 266-276]. Yet, such impairment was documented only with explicit conjugation tasks in the production domain. Little is known about whether it generalizes to other language modalities such as perception and whether it refers to implicit language processing or rather to intentional rule operations through executive functions. We investigated these issues by assessing perceptive processing of conjugated verb forms in a model of striatal dysfunction, namely, in Huntington's Disease (HD) at early stages. Rule application and lexical processes were evaluated in an explicit task (acceptability judgments on verb and nonword forms) and in an implicit task (lexical decision on frequency-manipulated verb forms). HD patients were also assessed in executive functions, and striatal atrophy was evaluated with magnetic resonance imaging (bicaudate ratio). Results from both tasks showed that HD patients were selectively impaired for rule application but lexical abilities were spared. Bicaudate ratios correlated with rule scores on both tasks, whereas executive parameters only correlated with scores on the explicit task. We argue that the striatum has a core function in linguistic rule application generalizing to perceptive aspects of morphological operations and pertaining to implicit language processes. In addition, we suggest that the striatum may enclose computational circuits that underpin explicit manipulation of regularities.
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Insistence on sameness (IS) in individuals with autism spectrum disorder (ASD) and their families may have utility in identifying meaningful subgroups for studying the pathophysiological and genetic pathways affected in ASD. The p...
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Insistence on sameness (IS) in individuals with autism spectrum disorder (ASD) and their families may have utility in identifying meaningful subgroups for studying the pathophysiological and genetic pathways affected in ASD. The primary objectives of the current study were to (1) characterize features of IS in parents of children with ASD and (2) examine their relationships with child IS symptoms. Participants were 2760 families who participated in the Simons Simplex Collection. Levels of parent IS were measured using the Broader Autism Phenotype Questionnaire (BAPQ). A factor analysis generated a BAPQ‐IS scale, consisting of a subset of 11 items from the original BAPQ‐Rigid scale. Correlations were run to examine the relationship between parent BAP and child IS variables. Correlations were found between parent IS and measures of child IS. Although relationships between parent and child IS features were statistically significant in this large sample, effect sizes were small. Results may be reflective of sample design that only included simplex families, where ASD severity may be predominantly driven by spontaneous mutations and less by common inherited risk from parents. In addition, child and parent measures used may have differentially captured features and severity of IS. Further research is needed on how IS can be accurately measured throughout development and across individuals with ASD and their unaffected family members to facilitate future studies on IS as a possible endophenotype for ASD. Autism Res 2018, 11: 1253–1263 . ? 2018 International Society for Autism Research, Wiley Periodicals, Inc. Lay Summary Previous research has suggested that insistence on sameness (IS) may be a heritable trait in autism spectrum disorder (ASD). The study examined whether children with high levels of IS had parents with IS tendencies. A small relationship was found between parent and child measures of IS. Future research is needed on measurement of insistence on sameness across individuals with and without ASD to further examine this relationship and improve understanding of the genetics of ASD.
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Pitch perception is critical for the perception of speech and music, for object identification, and for auditory scene analysis, whereby representations are derived for each sounding object in the environment from the complex soun...
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Pitch perception is critical for the perception of speech and music, for object identification, and for auditory scene analysis, whereby representations are derived for each sounding object in the environment from the complex sound wave that reaches the ears. The perceived pitch of a complex sound corresponds to its fundamental frequency. However, removal of energy at the fundamental does not alter the pitch because adults use the harmonics to derive the pitch (Bendor and Wang, 2005; Trainor, 2008). Although sound frequency is represented subcortically, the integration of harmonics into a representation of pitch does not occur until auditory cortex (Bendor and Wang, 2005). Given that auditory cortex is immature in young infants, we examined the development of cortical representations for pitch by measuring electrophysiological (EEG) responses to pitch changes that required processing the pitch of the missing fundamental. Adults and infants 4 months and older showed a mismatch negativity response to these pitch changes, but 3-month-old infants did not. Thus, cortical representations of the pitch of the missing fundamental emerge between 3 and 4 months of age, indicating that there is a profound change in auditory perception for pitch in early infancy.
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Pitch perception is critical for the perception of speech and music, for object identification, and for auditory scene analysis, whereby representations are derived for each sounding object in the environment from the complex soun...
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Pitch perception is critical for the perception of speech and music, for object identification, and for auditory scene analysis, whereby representations are derived for each sounding object in the environment from the complex sound wave that reaches the ears. The perceived pitch of a complex sound corresponds to its fundamental frequency. However, removal of energy at the fundamental does not alter the pitch because adults use the harmonics to derive the pitch (Bendor and Wang, 2005; Trainor, 2008). Although sound frequency is represented subcortically, the integration of harmonics into a representation of pitch does not occur until auditory cortex (Bendor and Wang, 2005). Given that auditory cortex is immature in young infants, we examined the development of cortical representations for pitch by measuring electrophysiological (EEG) responses to pitch changes that required processing the pitch of the missing fundamental. Adults and infants 4 months and older showed a mismatch negativity response to these pitch changes, but 3-month-old infants did not. Thus, cortical representations of the pitch of the missing fundamental emerge between 3 and 4 months of age, indicating that there is a profound change in auditory perception for pitch in early infancy.
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Initially, pHFOs were recorded with microelectrodes in the hippocampus of rodents and patients with mesial temporal lobe epilepsy (MTLE), but recently pHFOs have also been recorded with clinical depth and grid electrodes in multip...
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Initially, pHFOs were recorded with microelectrodes in the hippocampus of rodents and patients with mesial temporal lobe epilepsy (MTLE), but recently pHFOs have also been recorded with clinical depth and grid electrodes in multiple brain areas including the hippocampus and neocortex of patients with different types of epilepsy. One hypothesis is that pHFOs reflect fields of hypersynchronized action potentials (bursts of population spikes) within small discrete neuronal clusters responsible for seizure generation. Studies suggest that pHFOs can be used as a reliable biomarker for epileptogenesis, epileptogenicity, and the delineation of the epileptogenic region.
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Initially, pHFOs were recorded with microelectrodes in the hippocampus of rodents and patients with mesial temporal lobe epilepsy (MTLE), but recently pHFOs have also been recorded with clinical depth and grid electrodes in multip...
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Initially, pHFOs were recorded with microelectrodes in the hippocampus of rodents and patients with mesial temporal lobe epilepsy (MTLE), but recently pHFOs have also been recorded with clinical depth and grid electrodes in multiple brain areas including the hippocampus and neocortex of patients with different types of epilepsy. One hypothesis is that pHFOs reflect fields of hypersynchronized action potentials (bursts of population spikes) within small discrete neuronal clusters responsible for seizure generation. Studies suggest that pHFOs can be used as a reliable biomarker for epileptogenesis, epileptogenicity, and the delineation of the epileptogenic region.
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