Thesis (Ed.D.)--Boston University.

O objetivo deste estudo foi examinar os efeitos de dois manuseios por meiodo pontochave de controle na articulação do cotovelo, de acordo com o tratamento neuroevolutivo (TND),em comparação ao repouso, na atividade eletromiográfica dos músculos extensores do tronco em crianças com paralisia cerebral (PC). O ponto-chave na articulação do cotovelo pode conduzir a facilitação da atividade muscular quando utilizado em rotação externa (RE) umeral, ou produzir a inibição, quando utilizado em rotação interna (RI) umeral, com aumento e redução do sinal eletromiográfico (EMG), respectivamente, nos músculos extensores de tronco. Foi realizado um experimento cruzado randomizado para três seqüências de intervenções, envolvendo 40 crianças com PC. A eletromiografia (EMG) foi utilizada para mensurar a atividade muscular dos participantes, em repouso (R), durante o manuseio em RI e RE, utilizando o ponto-chave de controle na articulação do cotovelo, com o participante em sedestação. A atividade muscular foi registrada na região da quarta vértebra cervical (C4) e décima vértebra torácica (T10). Um intervalo de um minuto foi fornecido entre cada modo de manuseio. A função motora das crianças foi avaliada por meio do Gross Motor Function System (GMFCS). Um modelo linear misto para análise estatística demonstrou que o manuseio em RE causou um aumento no sinal EMG dos músculos extensores do tronco nas regiões da vértebra C4 (P = 0,007) e na vértebra T10 (P <0,001). Não houve diminuição na atividade muscular durante o manuseio em RI em qualquer ponto avaliado. O manuseio em RE provocou diferentes respostas no sinal EMG na região de T10, de acordo com o nível de GMFCS (P = 0,017), provocando aumento no nível 1 e 2 e queda gradual nos níveis seguintes (3-5). Na população deste estudo, o manuseio em RE facilitou a atividade dos músculos extensores de tronco nos níveis cervical e torácico. Por outro lado, o manuseio em RI não produziu a inibição com redução da atividade muscular, em qualquer dos segmentos analisados. Os efeitos do manuseio em RE de acordo com os níveis de classificação conforme o GMFCS deve ser futuramente explorado, com número amostral adequado para cada nível motor. / The aim of this study was to examine the effects of two handlings through the elbow joint key point according to the neurodevelopmental treatment (NDT), compared to the rest, on the electromyographic activity of trunk extensors muscles in children with cerebral palsy (CP). Elbow key point can lead to facilitation of muscle activity when used in humeral external rotation, or inhibition when used in humeral internal rotation, would result in an increase and a decrease of EMG signal, respectively, in the trunk extensor muscles. The experiment consisted on controlled 3-way crossover design involving 40 CP children. Electromyography (EMG) was used to measure the muscular activity at the rest (R) and during humeral internal rotation (IR) and humeral external rotation (ER) handling through the elbow joint key point, with children sitting. EMG recordings from trunk extensors muscles were performed at the fourth cervical (C4) vertebra and tenth thoracic (T10) vertebra levels. A one-minute interval for washout was provided between each mode of handling. Gross motor function was evaluated by means of the Gross Motor Function Classification System (GMFCS). Using a linear mixed model for statistical analysis, we found that humeral ER handling caused an increase on EMG signal of trunk extensor muscles at the C4 vertebra (P = 0.007) and T10 vertebrae (P < 0.001). There was no decrease on muscular activity during the humeral IR handling at any evaluated point. Humeral ER handling caused different responses on EMG signal at the T10 vertebra level, according to the GMFCS level (P = 0.017) with a gradual increase in 1-2 GMFCS levels, and a considerable drop from 3-5 GMFCS levels. In the target population of this study, humeral ER handling facilitated the trunk’s extensor muscle activity at cervical and thoracic levels. Humeral IR did not produce was not able to inhibit the muscle activity in any of the segments analyzed. Humeral ER handling effects on GMFCS levels should be explored further with sample size more adequate for each motor level.

Sensory information is represented in cortex by cascades of excitation, the patterns of which are constrained and biased by anatomical connections between neurons. Additionally, in the living animal, functional connectivity is dynamically adjusted by internally generated background activity, which varies by arousal state and behavioral context. Therefore, to understand how excitation propagates through the cortex, it is necessary to characterize the laminar flow of signal propagation as well as spontaneous network activity, which will constrain that propagation. This thesis characterizes the nature and mechanisms of awake cortical network dynamics, as well as the sources of sensory inputs in different cortical layers of the rat somatosensory system. Mammalian brains generate internal activity independent of environmental stimuli. Internally generated states may bring about distinct cortical processing modes. To investigate how brain state impacts cortical circuitry, we recorded intracellularly from the same neurons, under anesthesia and subsequent wakefulness, in the rat barrel cortex. In every cell examined throughout layers 2-6, wakefulness produced a temporal pattern of synaptic inputs differing markedly from those under anesthesia. Recurring periods of synaptic quiescence, prominent under anesthesia, were abolished by wakefulness, which produced instead a persistently depolarized state. This switch in dynamics was unaffected by elimination of afferent synaptic input from thalamus, suggesting that arousal alters cortical dynamics by neuromodulators acting directly on cortex. Indeed, blockade of noradrenergic, but not cholinergic, pathways induced synaptic quiescence during wakefulness. This thesis shows that subcortical inputs from the locus coeruleus-noradrenergic system can switch local recurrent networks into different regimes via direct neuromodulation. Having characterized the nature of wakeful dynamics, I next sought to characterize how sensory information propagates through the cortex. The thalamocortical projection to layer 4 (L4) of primary sensory cortex is thought to be the main route by which information from sensory organs reaches the neocortex. Sensory information is believed to then propagate through the cortical column along the L4→L2/3→L5/6 pathway. This thesis shows that sensory-evoked responses of L5/6 neurons derive from direct thalamocortical synapses, rather than the intracortical pathway. A substantial proportion of L5/6 neurons exhibit sensory-evoked postsynaptic potentials and spikes with the same latencies as L4. Paired in vivo recordings from L5/6 neurons and thalamic neurons revealed significant convergence of direct thalamocortical synapses onto diverse types of infragranular neurons. Pharmacological inactivation of L4 had no effect on sensory-evoked synaptic input to L5/6 neurons, and responsive L5/6 neurons continued to discharge spikes. In contrast, inactivation of thalamus suppressed sensory-evoked responses. This thesis shows that L4 is not an obligatory distribution hub for cortical activity, contrary to long-standing belief, and that thalamus activates two separate, independent "strata" of cortex in parallel.

A derivação ventricular externa (DVE) é usada em neurocirurgia para drenagem de liquor em pacientes com aumento da pressão intracraniana (PIC) em várias patologias (tumores, trauma, meningite e hemorragias intracranianas espontâneas), podendo servir como tratamento ou como forma de monitorização da variação da PIC. A principal complicação desse procedimento é a infecção (meningite e/ou ventriculite). Fatores de risco para o aumento da taxa de infecção em DVE incluem hemorragias intracranianas espontâneas. Neste estudo, analisamos as taxas de infecção em uma série de pacientes com hemorragia intracraniana espontânea que necessitaram de procedimento cirúrgico com DVE. Estudamos prospectivamente todos os 94 casos consecutivos de pacientes que necessitaram de DVE devido a hemorragia cerebral espontânea entre 2010 e julho de 2011 no Serviço de Neurocirurgia do Hospital Cristo Redentor, pertencente ao Grupo Hospitalar Conceição, localizado em Porto Alegre, Rio Grande do Sul, Brasil. A nossa série foi composta de 43 homens (45,7%) e 51 mulheres (54,3%). A média de idade de toda a amostra foi de 56,1 anos. O tempo médio de permanência com DVE foi de 7 dias. Foi observada uma taxa de mortalidade de 45% e uma taxa de infecção geral de 36%. Quando avaliamos a variável “Dias de DVE >10”, encontramos diferença significativa entre os grupos, ou seja, os pacientes que utilizaram DVE por mais de 10 dias apresentaram uma chance maior de infecção do que os pacientes que utilizaram DVE por um tempo menor ou igual a 10 dias (odds ratio = 3,1; IC 95%: 1,1–8,7). As demais variáveis avaliadas se mostraram sem significância estatística para esta amostra. Encontramos uma taxa de cultura positiva de 5,3%. Os dados do presente trabalho sugerem que a infecção relacionada à DVE foi uma complicação muito frequente, ocorrendo em 36,2 % dos casos. Porém, adotamos ventriculite como padrão de diagnóstico, conforme preconiza o Centers for Disease Control and Prevention (CDC). Considerando a alta mortalidade associada a hemorragias intracranianas espontâneas, talvez a adoção de um protocolo mais agressivo para essa população de pacientes possa melhorar as taxas de morbimortalidade desse tipo de doença. / External ventricular drainage (EVD) is used in neurosurgery to drain cerebrospinal fluid from patients with increased intracranial pressure (ICP) in a variety of conditions (tumors, trauma, meningitis, spontaneous intracranial hemorrhage). EVD can serve both as a therapeutic measure and as a tool for ICP monitoring. The major complication of this procedure is infection (meningitis and/or ventriculitis). Risk factors for EVD infection include spontaneous intracranial hemorrhage. This Study analyze infection rates in a series of patients with spontaneous intracranial hemorrhage who underwent surgical EVD placement. This prospective study included all patients who required EVD for spontaneous intracranial hemorrhage from January 2010 to July 2011 at the Neurosurgery Department of Hospital Cristo Redentor (HCR), Porto Alegre, Rio Grande do Sul, Brazil. Overall, 94 consecutive patients were included. The series comprised 43 men (45.7%) and 51 women (54.3%). Mean age across the sample was 56.1 years. The mean duration of EVD use was7 days. Overall sample mortality was 45%, and the overall infection rate was 36%. Assessment of the variable “EVD days >10” revealed a significant difference between groups: patients who had an EVD in place for longer than 10 days had higher odds of infection than patients in whom EVD was used for 10 days or fewer (odds ratio = 3.1; 95%CI 1.1–8.7) The other variables of interest were not statistically significant in this sample. We found a culture positivity rate of 5.3%. The findings of this study suggest that EVD infection was a very common complication, occurring in 36.2% of cases. However, we adopted ventriculitis as the standard diagnosis, as advocated by the Centers for Disease Control and Prevention. Considering the high lethality associated with intracranial hemorrhage, the adoption of a more aggressive treatment protocol for this patient population might improve morbidity and mortality rates.

La investigación pertenece al paradigma sociocrítico y abordaje de investigación acción participación OPS (1999), tuvo como objetivos: conocer, analizar y modificar el afrontamiento de las madres con hijos que padecen parálisis cerebral en la Clínica San Juan de Dios. El referencial teórico estuvo sustentado en los conceptos de afrontamiento de madres, Badia (2009), parálisis cerebral infantil, NINDES (2007) y modelo de atención de Callista Roy, Marriner (1999); los sujetos de investigación fueron 9 madres con niños entre 2 a 5 años de edad, que padecen parálisis cerebral de tipo espástica. La técnica de recolección de datos fue la entrevista semiestructurada, la muestra se obtuvo por saturación recolectándose datos antes y después de la intervención, luego se utilizó el análisis de contenido temático. Se tomó en cuenta los criterios de rigor científico y ético. Surgieron 3 categorías: De la incapacidad de afrontar de la enfermedad a afrontar los conflictos externos e internos a través del amor maternal y la fe en Dios, De las secuelas físicas propias de la enfermedad a mejorar la calidad de vida de los niños con parálisis cerebral infantil y como último Del abandono paterno al apoyo familiar en el cuidado compartido de un niño con parálisis cerebral infantil; cada una de ellas respectivamente analizadas y confrontadas de acuerdo a la realidad vivida. Finalmente, con el Programa Educativo “Afrontando Nuevos Desafíos” se logró, que muchas de las madres, alcancen condiciones satisfactorias que conlleven a un cuidado de calidad en su hijo con parálisis cerebral infantil. / Tesis

No description available.

This thesis examines the dynamical behaviour of incorporating NMDA (an excitatory neurotransmitter) for the electrodynamic model of the cerebral cortex. The model used is the mean-field model developed by Steyn-Ross et al. (2005) which describes the behaviour of the cortex in terms of parameters averaged over spatially localised populations. The behaviour of the model is determined by the four control parameters: inhibitory effect li, subcortical drive s, and NMDA neurotransmitter e ect set by an excitatory factor le and the magnesium concentration C. Adopting this model could give a better understanding of the cortex functionality and the anaesthetic mechanism. The model predicts that there are either one or three stationary states available to the cortex. We identify two of these with highly activated state and a quiescent state and focus on the transition between the two. Theoretical stability predictions (eigenvalue analysis) verified by a numerical simulation show that the system is unstable between the two Hopf bifurcations. In addition, in the stable region the steady states remains stable under a small perturbation, while in the unstable region either a transition between states or a limit cycle (oscillation) occurs depending on the position of the steady state.

Thesis (Ph.D.) -- University of Texas at Dallas, 2006 / Includes vita. Includes bibliographical references (leaves 135-148)

Systems biologists use interaction graphs to model the behaviour of biological systems at the molecular level. In an iterative process, such biologists observe the reactions of living cells under various experimental conditions, view the results in the context of the interaction graph, and then propose changes to the graph model. These graphs represent dynamic knowledge of the biological system being studied and evolve as new insight is gained from the experimental data. While numerous graph layout and drawing packages are available, these tools did not fully meet the needs of our immunologist collaborators. In this thesis, we describe the data display needs of these immunologists and translate these needs into visual encoding decisions. These decisions led us to create Cerebral, a system that uses a biologically guided graph layout and incorporates experimental data directly into the graph display. Our graph layout algorithm uses simulated annealing with constraints, optimized with a uniform grid to have an expected runtime of o(E/V). Small multiple views of different experimental conditions and a measurement-driven parallel coordinates view enable correlations between experimental conditions to be analyzed at the same time that the measurements are viewed in the graph context. This combination of coordinated views allows the biologist to view the data from many different perspectives simultaneously. To illustrate the typical analysis tasks performed, we analyze two datasets using Cerebral. Based on feedback from our collaborators, we conclude that Cerebral is a valuable tool for analyzing experimental data in the context of an interaction graph model.

Thesis (M.A.) - Simon Fraser University, 2005. / Theses (Dept. of Psychology) / Simon Fraser University. Also issued in digital format and available on the World Wide Web.