Methods for assessing small peripheral nerve fiber function objectively are limited. The cutaneous silent period (CuSP), a transient supression of electromyographic voluntary activity that follows painful stimuli, could serve as an objective functional measure of the A delta fibers. The aim of this study was to evaluate function of small diameter A delta nerve fibers using the CuSP in normals and in patients with both focal (carpal tunnel syndrome - CTS) and generalised (polyneuropathies - PNP) peripheral nerve injuries. The objectives of the study were the following: 1. To determine the CuSP normal values by age, gender, side, height and weight in healthy controls. 2. To study the topography and extension of the CuSP by changing recording and stimulating sites in healthy controls. 3. To evaluate the CuSP in patients with CTS of different severity and to compare these results with those of healthy controls. 4. To estimate the CuSP onset latency and duration in relation with median nerve evoked compound muscle action potential amplitude, distal latency and conduction velocity in patients with CTS. 5. To evaluate the CuSP in patients with PNP of different types and to compare these results with those of healthy controls. 6. To estimate the CuSP onset latency and duration in relation with median nerve evoked compound muscle action potential amplitude, distal latency and conduction velocity in patients with PNP. We investigated the CuSP of the upper and lower limbs of 50 normal... [to full text]

The corpus callosum provides a physical and functional connection between the two hemispheres of the brain allowing interactions between homologous cognitive, sensory and motor areas. In humans, the integrity of transcallosal connections between motor cortices can be evaluated quickly and non-invasively using transcranial magnetic stimulation (TMS) via the ipsilateral silent period (iSP). While the technique has been known for 20 years, many issues remain unsolved regarding which methods are best to elicit the iSP as an index of transcallosal inhibition. In addition, there is still limited information regarding the influence of individualized factors such as age on iSP measurements. This thesis investigates how common physiological and methodological factors influence the iSP in order to establish this method as a reliable index to assess the integrity of the transcallosal pathway linking primary motor cortices. In the first series of experiments, we used a previously described TMS protocol to elicit iSPs [1] to investigate changes in motor transcallosal inhibition in relation to individual factors linked to age, hand preference and history of concussions. A second series of methodological experiments examined the effects of stimulation intensity on the iSP and to determine its inter-session reliability. Our first series of experiments provided evidence that advancing age and history of concussions in young athletes were each independently associated with alterations in transcallosal inhibition. This was evidenced by changes in the duration of transcallosal inhibition (DTI) and in the latency of transcallosal inhibition (LTI) derived from iSP measurements. These experiments also revealed that the degree of hand preference in young adults was reflected in measures of transcallosal inhibition, so that mixed-handed individuals (i.e., ambidextrous) exhibited evidence of more efficient transcallosal transmission than either strong right or left handed individuals. The second series of experiments focusing on methodological aspects showed that the iSP duration (though not its onset) was influenced by stimulation intensity, increasing linearly with intensity up to 140% of the resting motor threshold (RMT). Our analysis further revealed that the probability of eliciting detectable iSP also increased with increasing intensity up to 130% RMT before reaching a plateau. A stimulation intensity of 130% of RMT appears to be optimal to elicit iSPs in healthy participants. In a subsequent study, we showed that iSP elicited at this stimulation intensity (i.e., 130% RMT) had good inter-session reliability. In light of these investigations, we recommend for future studies that, in addition to contraction of the homologous muscles of the opposite hand as proposed by Giovannelli et al 2009, that an intensity of 130% RMT should be used to elicit the iSP when assessing transcallosal inhibition between motor cortices.

No description available.

No description available.

Made available in DSpace on 2016-04-27T19:30:26Z (GMT). No. of bitstreams: 1 Marcia Juliana Santos.pdf: 3771158 bytes, checksum: 4665b58939795b108185e3d3a66f58c0 (MD5) Previous issue date: 2011-10-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this work, researching the1930s and 1940 with the aim to identify in natural films, posed, current affairs, documentaries and newsreels produced or commissioned by government agencies, discourses and understandings that were crucial to building diverse images of the city of São Paulo. We investigated several aspects that permeated the time interval between the crisis of fictional production (posed) in São Paulo, from and dated from the early 1930s, until the rise of the studios in São Paulo, from 1949, with the inauguration of Vera Cruz. An important film experience was done in the meantime, over the city, but not investigated or was questioned by historiography. In the period, non-fiction production has intensified, partly to meet a government demand to register, through film, urban change, social policies and they passed the state capital. We started from the practice of domestic and foreign cameraman to identify different cultural references, steeped in historical and social production. From the methodological point of view, work with sources (movies, newspapers, interviews, magazines, reports etc.) at all times sought to follow the paths of realization of these films. Both the government at the municipal, state and federal governments, as the modernist writers of São Paulo, analyze or produce film or immigrants living orders of the films contributed to the creation of images on the capital city. It has been argued by several sources of confrontation that was this production that started in the cinema, a way of telling a story with official advertisement objectives or documentary about the city / Neste trabalho, pesquisou-se às décadas de 1930 e 1940 com o objetivo de identificar, em filmes naturais, posados, atualidades, cinejornais e documentários, produzidos ou encomendados pelo poder público, discursos e compreensões que foram fundamentais para construir imagens diversas sobre a cidade de São Paulo. Foram investigados os diversos aspectos que permearam o intervalo de tempo, entre a crise da produção ficcional (posados), em São Paulo e datada do início da década de 1930, até a ascensão dos estúdios paulistas, a partir de 1949, com a inauguração da Vera Cruz. Uma importante experiência fílmica foi realizada, nesse meio tempo, sobre a cidade, mas que não foi problematizada ou investigada pela historiografia. No período, a produção não ficcional se intensificou, em parte para atender uma demanda do governo de registrar, por meio do cinema, as transformações urbanas, sociais e políticas pelas quais passavam a capital paulista. Partiu-se da prática do cinegrafista nacional e estrangeiro para identificar os diferentes referenciais culturais, históricos e sociais imersos na produção. Do ponto de vista metodológico, o trabalho com as fontes (filmes, jornais, entrevistas, revistas, relatórios etc.) procurou a todo instante seguir os percursos da realização desses filmes. Tanto o governo em âmbito municipal, estadual e federal, quanto os escritores modernistas de São Paulo, que analisavam ou produziam cinema ou os imigrantes que viviam das encomendas dos filmes, contribuíram para a elaboração de imagens sobre a capital paulista. Defendeu-se por meio da confrontação de fontes diversas que foi essa produção que iniciou, no cinema, um modo de contar uma história oficial com objetivos documentais ou de propaganda sobre a cidade

H TMS διακρίνεται έναντι άλλων εργαλείων απεικόνισης λόγω της ικανότητάς της να ενεργοποιεί νευρώνες σε επιλεγμένες φλοιϊκές περιοχές. Η παρούσα μελέτη προσπαθεί να διερευνήσει το νευροφυσιολογικό προφίλ της μυικής προκλητής απάντησης διάμεσου διακρανιακής μαγνητικής διέγερσης (TMS) σε ένα σεβαστό αριθμό ασθενών με σχιζοφρένεια υπό φαρμακευτική αγωγή. Σε 51 ασθενείς υπό φαρμακευτική αγωγή και διάγνωση σχιζοφρένειας και 51 υγιείς μάρτυρες απόλυτα σύμφωνους ως προς το φύλο, το ύψος και την ηλικία με τους ασθενείς που συμμετείχαν καταγράφηκαν κινητικά προκλητά δυναμικά (ΜΕΡ) από τον απαγωγό μυ του αντίχειρα μετά τον ερεθισμό του αντίπλευρου κινητικού φλοιού με ένα κυκλικό πηνίο. Μετρήθηκαν: w RMTh (resting motor threshold): Ο ουδός κινητικής ηρεμίας w SI-max (stimulus intensity for maximum MEP): Η ένταση ερεθίσματος που χρειάζεται για την καταγραφή του μέγιστου κινητικού προκλητού δυναμικού w Post-stimulus silent period: Την ανερέθιστη περίοδο που επάγεται μετά από ένα ερέθισμα που προκαλεί συγκεκριμένη μυική δραστηριότητα w MEP Latency: Λανθάνον χρόνος των κινητικών προκλητών δυναμικών MEP amplitude: Το εύρος των κινητικών προκλητών δυναμικών. Τα βασικά ευρήματα είναι η σαφώς υψηλότερη από τις φυσιολογικές τιμές, τιμή των RMTh και SI-max και τα δύο, ενδείξεις νευρωνικής ευοδωτικής δραστηριότητας στους ασθενείς σε σύγκριση με τους μάρτυρες. Ειδικότερα στην ομάδα των ασθενών που βρίσκονται σε θεραπεία με ζιπρασιδόνη παρουσιάστηκε το υψηλότερο SI-max και στα δύο ημισφαίρια και το υψηλότερο RMTh στο αριστερό ημισφαίριο. Οι ασθενείς στην ομάδα που ελάμβαναν ολανζαπίνη παρουσίασαν το χαμηλότερο RMTh για το αριστερό ημισφαίριο και αυτοί σε θεραπεία με κουατιεπίινη παρουσίασαν τιμές ανάμεσα στις τιμές των δύο προηγούμενων ομάδων. Όταν χρησιμοποιήθηκε ένταση ερεθίσματος (SI) σχετικής τιμής με το RMTh, η ανερέθιστη περίοδος βρέθηκε μεγαλύτερη στους ασθενείς από ότι στους μάρτυρες ενώ δεν παρατηρήθηκε καμία διαφορά ανάμεσα στις δύο μεγάλες ομάδες ασθενών και μαρτύρων όταν χρησιμοποιήθηκε σταθερής έντασης ερέθισμα (SI). Συμπεράναμε, ότι οι αλλαγές στις παραμέτρους που μετρήθηκαν, μπορούν να εξηγηθούν από βασικές μεταβολές της ενδοφλοιϊκής ευοδωτικής κινητικής δραστηριότητας που ακολουθείται από διαφοροποιήσεις της φλοιϊκής αναστολής, οι οποίες μπορούν να αποδοθούν είτε στην σχιζοφρένεια είτε στην φαρμακευτική αγωγή ή στην αλληλεπίδρασή τους. / Trancranial magnetic stimulation (TMS) provides a non-invasive means for exploring physiological alterations of central motor control in a variety of neuropsychiatric diseases. The present study aimed to assess the neurophysiological profile of muscle evoked responses to a standard TMS procedure in a considerable number of medicated patients with schizophrenia. Fifty-one patients with diagnosis of schizophrenia and 51 sex- and age-matched healthy subjects were enrolled in the study. Motor evoked potential (MEP) from abductor pollicis brevis muscle was elicited by stimulation of the contralateral motor cortex with a circular coil. The hot-spot was marked. Were measured: ¨ the resting motor threshold (RMTh), ¨ the stimulus intensity for maximum MEP (SI-max), ¨ the post-stimulus silent period of voluntary muscle activity and ¨ MEP latency and amplitude. The main findings were the significantly higher than normal values for RMTh and SI-max, which are both indices of neuronal excitability. In particular, patients who had ziprasidone in their therapeutic regimen demonstrated the highest SI-max for both hemispheres and highest RMTh for left hemisphere, patients receiving olanzapine demonstrated the lowest RMTh for left hemisphere and those on quetiapine showed intermediate values. Silent period was longer in the patients as opposed to controls when a RMTh-related SI was used and did not differ between the two groups when a fixed SI was used. We concluded that the observed TMS changes could be interpreted by primary alterations of intracortical motor excitability followed by defects of cortical inhibition and should be attributed to schizophrenia, antipsychotic medication or the interaction between both factors.

Made available in DSpace on 2016-06-02T20:25:11Z (GMT). No. of bitstreams: 1 3882.pdf: 2333238 bytes, checksum: 163f8e99897c5680633e31a2687b2553 (MD5) Previous issue date: 2010-10-19 / The aim of this work was to investigate factors that could be related to the silence (in the classroom) of students of English as a foreign language at advanced levels of study, a phenomenon that we will call prolonged silence period, based on Krashen‟s silent period concept. According to this concept, it is natural that students at the beginning of the learning process of a new language go through a period in which they remain silent, just receiving linguistic input, until they have acquired some knowledge and the necessary confidence to start talking. Some students, however, tend to remain silent in class, even at higher levels of language study. In this investigation, we focus on how these students act in class. This work is based on studies about affective factors involved in the language teaching and learning process carried out by Brown (2000), Almeida Filho (1993) and Krashen & Terrell (1998), on studies about students beliefs regarding this process, carried out by Vieira-Abrahão and Barcelos (2006), Barcelos (2001) and Almeida Filho (1993), among others. The methodology of the research involves interviews, field notes, questionnaires, student´s retrospective selfevaluation, and audio and video recordings with students from two intermediateadvanced level groups and three advanced level groups of a private language institute. The goal is to identify and discuss possible factors that contribute to the lack of oral participation of these students in class, as well as their beliefs regarding the foreign language teaching and learning process, especially as it is related to oral practice. Through this work we verified, for example, the existence of a belief according to which being at an advanced level of learning of the target language means not being allowed to make mistakes, due to the thought that at this level of studies the oral production must be free from errors. Consequently, to avoid making such errors, some students opt to remain silent in class. / O foco deste trabalho está voltado para a investigação de fatores que possam estar relacionados ao silêncio (em sala de aula) de alunos de língua inglesa de níveis intermediário-avançado e avançado, fenômeno que denominaremos período silencioso prolongado, a partir do conceito de silent period (período silencioso) de Krashen. De acordo com esse conceito, é natural que alunos no início do processo de aprendizagem de uma nova língua vivenciem um período no qual permaneçam em silêncio, apenas recebendo insumo lingüístico, até que tenham adquirido certo conhecimento e a confiança necessária para começarem a falar. Alguns alunos, no entanto, tendem a permanecer em silêncio durante as aulas, mesmo já em estágios mais avançados de estudos da língua. Focalizamos, em nossa análise, a atuação desses alunos. O trabalho baseia-se em estudos sobre fatores afetivos envolvidos no processo de ensino e aprendizagem de línguas realizados por Brown (2000), Almeida Filho (1993) e Krashen e Terrell (1998), em estudos sobre crenças de alunos a respeito desse processo, realizados por Vieira-Abrahão e Barcelos (2006), Barcelos (2001) e Almeida Filho (1993), entre outros. A metodologia da pesquisa envolve entrevistas, notas de campo, questionários, auto-avaliação retrospectiva de aprendizes e gravações em áudio e vídeo com alunos de duas turmas de nível intermediário-avançado e três turmas de nível avançado em um instituto privado de idiomas. O objetivo é identificar e discutir possíveis motivos que levam alguns desses alunos a não interagir em sala de aula, assim como suas crenças a respeito do processo de ensino e aprendizagem de língua estrangeira, notadamente no que se refere à prática da oralidade. Por meio deste estudo, constatamos, por exemplo, a existência de uma crença segundo a qual estar em nível avançado de aprendizagem da língua significa a impossibilidade de que erros sejam cometidos, em virtude da expectativa de que nesse nível de estudos a produção oral deve estar isenta de erros. Consequentemente, para evitar que tais erros ocorram, alguns aprendizes optam por ficar em silêncio em sala de aula.