1,720,964 research outputs found
Automatic detection of cataplexy
Full text linkObjective: Although being the most specific symptom of narcolepsy type 1 (NT1), cataplexy is currently investigated by clinical interview only, with potential diagnostic pitfalls. Our study aimed at testing the accuracy of an automatic video detection of cataplexy in NT1 patients vs. non-cataplectic subjects undergoing a standardized test with emotional stimulation. Methods: Fifteen drug-naive NT1 patients and 15 age- and sex-balanced non-cataplectic subjects underwent a standardized video recording procedure including emotional stimulation causing laughter. Video recordings were visually inspected by human scorers to detect three typical cataplexy facial motor patterns (ptosis, mouth opening and head drop), and then analysed by SHIATSU (Semantic-based HIearchical Automatic Tagging of videos by Segmentation using cUts). Expert-based and automatic attack detection was compared in NT1 patients and non-cataplectic subjects. Results: All NT1 patients and none of the non-cataplectic subjects displayed cataplexy during emotional stimulation. Automatic detection correlated well with experts’ assessments in NT1 with an overall accuracy of 81%. In non-cataplectic subjects, automatic detection falsely identified cataplexy in two out of 15 (13.3%) subjects who showed active eyes closure during intense laughter as a confounder with ptosis. Conclusions: Automatic cataplexy detection by applying SHIATSU to a standardized test for video documentation of cataplexy is feasible, with an overall accuracy of 81% compared to human examiners. Further studies are warranted to enlarge the range of elementary motor patterns detected, analyse their temporal/spatial relations and quantify cataplexy for diagnostic purposes
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
A standardized test to document cataplexy
No full textObjective/Background: Cataplexy is the pathognomonic symptom of narcolepsy type 1 (NT1). Since it is considered difficult to be directly observed or documented by clinicians, its diagnosis relies mainly on history taking. Our study aimed at testing the feasibility of a standardized video recording procedure under emotional stimulation to document cataplexy in the diagnostic work-up of suspected hypersomnia of central origin. Patients/Methods: Two-hundred-eight consecutive patients underwent the diagnostic work-up and reached the final diagnosis of NT1 (n = 133), idiopathic hypersomnia or narcolepsy type 2 (IH/NT2 group, n = 33), or subjective excessive daytime sleepiness (sEDS group, n = 42). All subjects underwent a standardized video recording procedure while watching funny movies selected according to individual preferences, and a technician blind to clinical features reviewed the recordings to identify hypotonic phenomena that were finally confirmed by patients. Results: The video recording under emotional stimulation captured hypotonic phenomena in 72.2%, 9.1% and 4.8% of NT1, IH/NT2, and sEDS subjects (p < 0.0001), respectively. When tested against CSF hypocretin deficiency, the documentation of a hypotonic episode at the test showed an area under the ROC curve of 0.823 ± 0.033 (p < 0.0001). NT1 patients under anticataplectic medications showed less frequently hypotonic episodes than untreated ones (48.0% vs 77.8%, p = 0.003). Conclusions: A standardized video recording procedure under emotional stimulation can help in the characterization of suspected hypersomnia of central origin. Further multi-center studies are warranted to extend the present findings and integrate a shared procedure for the laboratory work-up of narcolepsy
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
The spectrum of REM sleep-related episodes in children with type 1 narcolepsy
Full text linkType 1 narcolepsy is a central hypersomnia due to the loss of hypocretin-producing neurons and characterized by cataplexy, excessive daytime sleepiness, sleep paralysis, hypnagogic hallucinations and disturbed nocturnal sleep. In children, close to the disease onset, type 1 narcolepsy has peculiar clinical features with severe cataplexy and a complex admixture of movement disorders occurring while awake. Motor dyscontrol during sleep has never been systematically investigated. Suspecting that abnormal motor control might affect also sleep, we systematically analysed motor events recorded by means of video polysomnography in 40 children with type 1 narcolepsy (20 females; mean age 11.8 ± 2.6 years) and compared these data with those recorded in 22 age- and sex-matched healthy controls. Motor events were classified as elementary movements, if brief and non-purposeful and complex behaviours, if simulating purposeful behaviours. Complex behaviours occurring during REM sleep were further classified as 'classically-defined' and 'pantomime-like' REM sleep behaviour disorder episodes, based on their duration and on their pattern (i.e. brief and vivid-energetic in the first case, longer and with subcontinuous gesturing mimicking daily life activity in the second case). Elementary movements emerging either from non-REM or REM sleep were present in both groups, even if those emerging from REM sleep were more numerous in the group of patients. Conversely, complex behaviours could be detected only in children with type 1 narcolepsy and were observed in 13 patients, with six having 'classically-defined' REM sleep behaviour disorder episodes and seven having 'pantomime-like' REM sleep behaviour disorder episodes. Complex behaviours during REM sleep tended to recur in a stereotyped fashion for several times during the night, up to be almost continuous. Patients displaying a more severe motor dyscontrol during REM sleep had also more severe motor disorder during daytime (i.e. status cataplecticus) and more complaints of disrupted nocturnal sleep and of excessive daytime sleepiness. The neurophysiological hallmark of this severe motor dyscontrol during REM sleep was a decreased atonia index. The present study reports for the first time the occurrence of a severe and peculiar motor disorder during REM sleep in paediatric type 1 narcolepsy and confirms the presence of a severe motor dyscontrol in these patients, emerging not only from wakefulness (i.e. status cataplecticus), but also from sleep (i.e. complex behaviours during REM sleep). This is probably related to the acute imbalance of the hypocretinergic system, which physiologically acts by promoting movements during wakefulness and suppressing them during sleep
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
Phenomenology and psychiatric correlates of pseudocataplexy
Full text linkStudy objectives: Pseudocataplexy is a rare functional neurological disorder that mimics cataplexy, pathognomonic for narcolepsy type 1 (NT1). We describe the psychiatric comorbidity and personality traits of patients with pseudocataplexy versus NT1 cases. Methods: The case-control observational study enrolled consecutive patients with pseudocataplexy and a control group of age-matched consecutive NT1 patients. The diagnostic work-up included a structured interview, 48-hour polysomnography, multiple sleep latency test, cataplexy provoking test, and hypocretin-1 measurement in cerebrospinal fluid.All participants were administered Beck Depression Inventory, State-Trait Anxiety Inventory, Patient Health Questionnaire-15 (PHQ-15), Personality Inventory for DSM-5 brief form, and quality of life (QoL) measurement by 36-item Short Form health survey (SF-36). Results: Fifteen patients with pseudocataplexy and 30 with NT1 were included. Despite the suspicion of possible cataplexy, none of the pseudocataplexy participants fulfilled international diagnostic criteria for NT1. Pseudocataplexy patients presented higher rates of moderate state anxiety (40% vs. 10%, p=0.018), medium level of somatic symptoms, defined by PHQ-15 score >10 (66.7% vs. 16.7%, p=0.003), and a trend towards moderate-to-severe depressive symptoms (33.3% vs. 10%, p=0.054) compared to NT1. No significant differences in personality traits emerged. Pseudocataplexy patients had worse QoL profile in almost all SF-36 domains including physical (mean±SD: 37.7±9.88 vs. 51.13±7.81, p<0.001) and mental (mean±SD: 33.36±12.69 vs.42.76±11.34, p=0.02) summary scores. Conclusions: Patients with pseudocataplexy present more severe psychiatric symptoms and a lower QoL profile in comparison with patients with NT1. The severe somatoform and affection impairment in pseudocataplexy may explain the poorer QoL and should require a tailored therapeutic approach
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