1,720,958 research outputs found
Artifacts
No full textThe term “artifact” refers to any element of extra-cerebral origin which can be recorded in the EEG channels, disturbing the acquisition of the tracing. Artifacts may derive from many sources, internal or external to the patient, and have several characteristics that may suggest their origin. Both the technician and the physician should be able to recognize the artifacts, for the possibility of misinterpreting the examination. As a matter of fact, even though many artifacts are easily detectable, some may remind pathological graphoelements and, therefore, be the cause for incorrect EEG interpretation. However, some artifacts are not considered a disturbance in the EEG recording, and they are instead considered useful for its interpretation. For example, eye movement artifacts, due to their typical morphology and localization, provide immediate information on the correct position of the electrodes, amplification parameters, and the patient’s emotional state and alertness; they are also useful in identifying the sleep stages. Sometimes, the ECG artifact can reveal cardiac arrhythmias. In epileptic patients, the appearance of muscular, ocular, or movement artifacts may indicate the seizure onset. In this chapter, the most common artifacts will be described, to give physicians and technicians the tools to detect and - possibility - to avoid their recording
Neuromonitoring and Emergency EEG
No full textIntraoperative and Intensive Care Unit (ICU) EEG monitoring is very useful in cases of possible brain damage, for example, during carotid endarterectomy, cardiac surgery and neurosurgery, or when subclinical seizures are suspected. Continuous EEG (cEEG) monitoring during surgery is a valid and sensitive instrument for recognizing and/or preventing perioperative ischemic insults or any epileptiform activity responsible for convulsive or nonconvulsive symptoms. Furthermore, it allows brain functions monitoring for anesthetic drug administration, to determine the depth of anesthesia and for adjusting drug levels to achieve a predefined neural effect, such as burst suppression. In ICU, cEEG monitoring is essential to identify electrical discharges that occur frequently in critically ill patients and that are often clinically undetected, but potentially harmful if the diagnosis and the treatment are delayed. In the last years, cEEG monitoring has become a widespread practice, especially because of the use of new digital equipments, which are extremely compact and easy to use, not requiring a constant connection to the power grid and thus avoiding artifacts. EEG tracings can be visualized in real-time or analyzed after acquisition, either online or offline, with qualitative and/or quantitative methods. Finally, it is worth remembering that EEGs can be recorded bedside from a peripheral recording unit and then sent to the central unit, so that neurophysiologists can examine the recordings from distance and process them without interfering with the patients’ management
Scuba Diving Is Not Associated With High Prevalence of Headache: A Cross-Sectional Study in Men
No full textObjective. To study the prevalence of cephalalgia in male divers. Background.-Scuba divers work in stressing environments and have a high cerebrovascular risk, both conditions which are supposed to contribute to the genesis of cephalalgia. However, no study assessed expressly the prevalence of cephalalgia in divers, to date. Methods.-We enrolled 201 professional male scuba divers (41.0 +/- 7.2 years) and controls (41.1 +/- 7.2 years), and the risk ratio and its corresponding 95% confidence of suffering from cephalalgia was calculated. Results.-We found that 16% of divers and 22% of matched controls were affected by cephalalgia (P>.05), accounting for a risk ratio of 0.71 (95% CI 0.47-1.07). Divers reported fewer attacks per month (1.8 +/- 0.7, n = 32) with regard to controls (2.5 +/- 1.8, n = 45) (P=.02), but no differences concerning age at onset and severity were detected (P>.05). Divers suffered from migraine, migraine with aura and tension headache as much as controls. Conclusion.-Scuba diving, an intense physical activity characterized by cerebral micro-vascular distress, is not associated with cephalalgia, as a whole, or migraine, tension headache or migraine with aura, more commonly than in a matched, non-diving, population. A longitudinal study may disclose if diving may act as a protective factor in the occurrence of crises of cephalalgia
Effect of 24-h continuous rotigotine treatment on stationary and non-stationary locomotion in de novo patients with Parkinson disease in an open-label uncontrolled study
No full textThe aim of this study was to investigate the effect of a rotigotine transdermal patch on stationary and non-stationary locomotion in de novo Parkinson disease (PD) patients in an open-label uncontrolled study. A 3-D gait analysis system was used to investigate four different locomotor tasks: steady-state linear walking, gait initiation, gait termination and 180°-turning. A series of gait variables were measured for each locomotor task. PD patients who received rotigotine treatment (4-8 mg) displayed: (1) increased step length, gait speed, cadence and arm oscillations, and reduced double support duration and step asymmetry during steady-state linear gait; (2) increased initial step length during gait initiation; (3) increased final step length and gait speed, and decreased stability index during gait termination; (4) decreased duration of turning and head-pelvis delays during 180°-turning. The main finding that emerges from the present study is that the dopamine agonist rotigotine can improve various aspects of gait in de novo PD patients
Effects of eslicarbazepine acetate on lipid profile and sodium levels in patients with epilepsy
No full textSeveral studies have demonstrated that treatment with enzyme-inducing antiepileptic drugs is associated with increased serum lipid levels. Eslicarbazepine acetate (ESL) is a novel antiepileptic drug specifically designed with the objective to identify carbamazepine and oxcarbazepine analogues with favorable pharmacodynamic and pharmacokinetic profiles. The present study aimed to assess the changes in lipid profile and sodium levels in patients with epilepsy taking ESL as adjunctive therapy
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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