1,721,119 research outputs found
Early recognition of Parkinson's disease. Objectifiable non-motor symptoms and biomarkers
No full textThe clinical diagnosis of Parkinson's disease (PD) according to the UK Brain Bank criteria is based on the presence of motor symptoms and the response to dopaminergic medication. According to these criteria the clinical diagnosis is delineated too late when more than 50 % of the dopaminergic neurons are already degenerated. In recent years interest has shifted increasingly more towards non-motor symptoms (NMS), such as rapid eye movement (REM) sleep behavior disorder (RBD), constipation, hyposmia and neuropsychiatric as well as cognitive symptoms. It was shown that NMS can precede the motor symptoms by some years and may thus possibly enable support of an earlier clinical diagnosis. Furthermore, cerebrospinal fluid or blood biomarkers as well as brain imaging techniques can objectively support an earlier diagnosis of PD. This article reviews important NMSs (e.g. RBD, hyposmia and neuropsychiatric/cognitive symptoms) as well as the current status on biomarkers and brain imaging in early (premotor) phases of PD and their relevance for the early diagnosis
Fatigue and depression predict health-related quality of life in patients with pediatric-onset multiple sclerosis
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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
Cognitive dysfunction in Parkinson's disease: from early symptoms to diagnosis
Full text linkParkinson’s disease (PD) is a chronic neurodegenerative disorder that affects over six million people worldwide. It is classically characterized by the emergence of motor symptoms including bradykinesia/akinesia, rigidity, tremor, and postural instability. In the past decade, PD has increasingly been recognized as a mixed motor, non-motor and multiorgan disorder rather than a pure movement disorder. Cognitive impairment is a common non-motor complication of PD that is associated with significant disability in patients and caregiver burden. The thesis covers three aspects of cognitive dysfunction in PD through three studies.
The first study, “Cognitive dysfunction in prodromal Parkinson’s disease: a qualitative review,” focuses on cognitive symptoms in prodromal PD. Today it is known that, by the time motor symptoms allow for clinical diagnosis, 40-60% of the dopaminergic neurons have already degenerated. The period of time in which neurodegeneration progresses in the absence of classical motor symptoms that allow a clinical diagnosis is termed the “prodromal phase of PD.” While other non-motor symptoms that represent possible prodromal symptoms of PD have been described in some detail, the occurrence and characteristics of cognitive decline in this early phase of the disease are less well understood. The aim of the review was to summarize the current state of research on cognitive changes in prodromal PD. It shows that only a small number of longitudinal studies have been conducted that examine cognitive functions in individuals with a subsequent PD diagnosis. However, when considering data from at-risk groups, the evidence suggests that cognitive decline may occur in a substantial number of individuals who have the potential for developing PD. In terms of specific cognitive domains, executive function in particular and, less frequently, memory scores, were reduced. Prospective, longitudinal studies are thus needed to clarify whether cognitive, and specifically executive, decline might be added to the prodromal non-motor symptom complex that may precede motor manifestation of PD by years. Such information may help in updating the risk scores used for early identification of PD.
The second study, “Verbal Memory Declines More in Female Patients with Parkinson’s Disease: the Importance of Gender-Corrected Normative Data,” concerns gender-specific profiles of cognitive function in patients with PD. So far, little data is available, the findings have been inconsistent, and possible disease-confounding factors have not been adequately considered. The LANDSCAPE study on cognition in PD enrolled 656 PD patients; raw values and age-, education-, and gender-corrected Z-scores were compared between genders. Motor symptoms, disease duration, levodopa equivalent daily dose, depression, and age and education for the raw value analysis were taken as covariates. The raw score analysis replicated the results of previous studies in that female PD patients were superior in terms of verbal memory, while men outperformed women in visuoconstruction and figural memory. In contrast, the gender-corrected Z-scores showed the men to be superior in verbal memory, while no difference was found for the visuospatial tests. It can be concluded that normative data corrected for gender and other sociodemographic variables are relevant, since they may elucidate a markedly different cognitive profile compared to raw scores. Our study also suggests that verbal memory decline is greater in women than in men with PD. Future studies are needed to replicate these findings, to examine the progression of gender-specific cognitive decline in PD, and to define the different underlying mechanisms of this dysfunction.
The third study, “Screening for Cognitive Impairment in Parkinson’s Disease: Improving the Diagnostic Utility of the MoCA through Subtest Weighting,” deals with cognitive screening in PD, which is highly relevant to clinical practice. The Montreal Cognitive Assessment (MoCA) is a screening test that is frequently used in PD to detect mild cognitive impairment (PD-MCI) and Parkinson’s disease dementia (PD-D). However, the subtests’ proportional representation in the MoCA total score does not seem reasonable. An empirically based alternative scoring system of the MoCA that is based on subtests´ individual sensitivity and specificity, and which aims to increase the instrument’s overall diagnostic accuracy, was developed and underwent preliminary evaluation. Diagnostic accuracy increased with the new MoCA scoring algorithm. In the first substudy, the sensitivity of detecting cognitive impairment increased from 62.5% to 92%, while specificity decreased only slightly from 77.7% to 73%; in the second substudy, sensitivity increased from 68.8% to 81.3%, while specificity remained stable at 75%. It can be concluded that the sensitivity of the MoCA can be enhanced substantially by an empirically based weighting procedure, and that the proposed scoring algorithm may better serve the MoCA’s purpose as a screening tool for the detection of cognitive dysfunction in PD patients than the original scoring. Further research with larger sample sizes is necessary to establish the efficacy of the alternate scoring system
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
Intelligence Quotient and Cognitive Fatigue are Independent Predictors of Cognitive Deficit in Pediatric MS Patients
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