1,720,986 research outputs found
Working memory, attention and planning abilities in NKX2.1-related chorea
No full textBackground: Although NKX 2.1 related chorea has been considered benign due to the favourable course of motor phenotype during life, the neurological condition is not limited to chorea, including non-motor symptoms in the developmental, cognitive and psychiatric domain. Aim of our study was to test working memory, attention and planning abilities of a cohort of NKX2.1 choreic patients compared to healthy controls. Methods: patients and healthy controls were assessed for working memory (Visual Digit Span test), response inhibition and sustained attention (Cued Go/No-Go test), and spatial problem-solving and planning task (Tower of London test). For experimental protocol, we used a computer based tool for neuropsychological experiments, Inquisit 5.0 software (Millisecond Software®). Non-parametric tests were performed for statistical analysis. Results: six patients and fifteen healthy paediatric controls were recruited. In the Digit Span test, both in forward and backward recall, patients showed statistically significant lower scores than controls. In the Cued Go/No-Go test as well as in the Tower of London, NKX 2.1 patients showed similar scores in the error rate and total score respectively, whereas in both tests they appeared to be slower than controls suggesting a poor performance in the execution of the tests. Conclusions: our findings demonstrate that patients with NKX2.1-related chorea show a selective impairment in working memory with increased latencies in both planning and attention. A developmental alteration of the cholinergic neurotransmission in the basal forebrain and the disruption of striatal networks could explain, at least in part, this neuropsychological profile
Alternating hemiplegia of childhood: Understanding the genotype–phenotype relationship of ATP1A3 variations
No full textAlternating hemiplegia of childhood (AHC) is a rare neurological disorder affecting children with an onset before 18 months. Diagnostic clues include transient episodes of hemiplegia alternating in the laterality or quadriparesis, nystagmus and other paroxysmal attacks as tonic and dystonic spells. Epilepsy is also a common feature. In the past, a great effort has been done to understand the genetic basis of the disease leading to the discovery of mutations in the ATP1A3 gene encoding for the alpha3 subunit of Na+/ K+ATPase, a protein already related to another disease named Rapid Onset Dystonia Parkinsonism (RDP). ATP1A3 mutations account for more than 70% of cases of AHC. In particular, three hotspot mutations account for about 60% of all cases, and these data have been confirmed in large population studies. Specifically, the p.Asp801Asn variant has been found to cause 30–43% of all cases, p.Glu815Lys is responsible for 16–35% of cases and p. Gly947Arg accounts for 8–15%. These three mutations are associated with different clinical phenotype in terms of symptoms, severity and prognosis. In vitro and in vivo models reveal that a crucial role of Na+ /K+ ATPase pump activity emerges in maintaining a correct membrane potential, survival and homeostasis of neurons. Herein, we attempt to summarize all clinical, genetic and molecular aspects of AHC considering ATP1A3 as its primary disease-causing determinant
Acute movement disorders in childhood
No full textAcute-onset movement disorders (MDs) are an increasingly recognized neurological emergency in both adults and children. The spectrum of possible causes is wide, and diagnostic work-up is challenging. In their acute presentation, MDs may represent the prominent symptom or an important diagnostic clue in a broader constellation of neurological and extraneurological signs. The diagnostic approach relies on the definition of the overall clinical syndrome and on the recognition of the prominent MD phenomenology. The recognition of the underlying disorder is crucial since many causes are treatable. In this review, we summarize common and uncommon causes of acute-onset movement disorders, focusing on clinical presentation and appropriate diagnostic investigations. Both acquired (immune-mediated, infectious, vascular, toxic, metabolic) and genetic disorders causing acute MDs are reviewed, in order to provide a useful clinician’s guide to this expanding field of pediatric neurology
Cognitive assessment in GNAO1 neurodevelopmental disorder using an eye tracking system
No full textGNAO1 gene mutations are associated with a neurodevelopmental disorder characterized by developmental delay, epilepsy, and movement disorder. Eye tracking and eye movement analysis are an intriguing method to assess cognitive and language function and, to the best of our knowledge, it has never been tested in a standardized way in GNAO1. GNAO1 children are usually wheelchair-bound and with numerous motor constrains, including dystonic movements and postures, heterotropia, and hypotonia, making the cognitive assessment arduous. These contribute to the burden and disability, with a high level of frustration of caregivers and patients. We have herein demonstrated that, through an eye tracking system, six GNAO1 patients evaluated showed variable degrees of communicative intent through intentionally directed gaze. Moreover, three of these were able to complete a cognitive evaluation, and showed normal fluid intelligence and lexical comprehension. In conclusion, in GNAO1-related disorders, the degree of cognitive development is underestimated; eye tracking technologies may help in overcome these boundaries
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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