O potencial evocado motor facial (PEMF) tem-se mostrado um excelente método de monitorização do nervo facial, gerando resultados bastante confiáveis e reprodutíveis no que tange à predição da função facial pós-operatória. O critério eletrofisiológico mais utilizado até então para tanto tem sido a relação de amplitude do PEMF final-valor de base. Os objetivos deste trabalho foram avaliar as alterações intraoperatórias da amplitude e da complexidade do PEMF, correlacioná-las com o prognóstico facial no pós-operatório imediato e tardio e verificar se amplitude e complexidade constituem variáveis independentes de predição funcional. Os registros dos potenciais intraoperatórios dos músculos orbiculares do olho e da boca de 35 pacientes portadores de schwannoma vestibular (SV) foram coletados e analisados retrospectivamente de acordo com tempos cirúrgicos preestabelecidos: inicial, abertura da dura-máter, dissecação do tumor (TuDis), ressecção do tumor (TuRes) e final. No pós-operatório imediato, a função facial apresentou uma significativa correlação negativa com as relações de amplitude do PEMF durante a TuDis, a TuRes e ao final do procedimento nos músculos orbiculares do olho (p =0,003, 0,055 e 0,028, respectivamente) e da boca (p=0,002, 0,104 e 0,014, respectivamente). No último seguimento, entretanto, a correlação foi significativa apenas para o músculo orbicular da boca, durante a TuDis (p=0,005) e ao final do procedimento (p=0,102). As variações da complexidade dos potenciais alcançaram resultados mais significativos tanto no pós-operatório imediato, quanto no tardio, de forma que houve uma correlação negativa no músculo orbicular do olho apenas nas medidas finais (imediato, p=0;023; seguimento, p=0,116) e no músculo orbicular da boca durante a TuDis, a TuRes e a medida final (imediato, p=0,071, 0,000 e 0,001, respectivamente; seguimento, p=0,015, 0,001 e 0,01, respectivamente). As alterações intraoperatórias das relações de amplitude e de complexidade dos PEMFs parecem representar variáveis independentes, podendo ser utilizadas na predição da função facial pós-operatória durante cirurgias de ressecção de SV. Baseados nos resultados deste trabalho, a monitorização evento-valor de base é bastante útil, justificando mudanças imediatas da estratégia cirúrgica, com o intuito de reduzir as chances de uma lesão definitiva do nervo facial. / Facial motor evoked potential (FMEP) amplitude ratio reduction at the end of the surgery has been identified as a good predictor for postoperative facial nerve outcome. We sought to investigate variations in FMEP amplitude and waveform morphology during vestibular schwannoma (VS) resection and to correlate these measures with postoperative facial function immediately after surgery and at the last follow-up. Besides we analyzed the relationship between quantitative parameters. Intraoperative orbicularis oculi and oris muscles FMEP data from 35 patients undergoing surgery for VS resection were collected, then analyzed by surgical stage: initial, dural opening, tumor dissection (TuDis), tumor resection (TuRes) and final. Immediately after surgery, postoperative facial function correlated significantly with the FMEP amplitude ratio during TuDis, TuRes and final in both the orbicularis oculi (p´s=0.003, 0.055 and 0.028, respectively) and oris muscles (p´s=0.002, 0.104 and 0.014, respectively). At the last follow-up, however, facial function correlated significantly with the FMEP amplitude ratio only during TuDis (p=0.005) and final (p=0.102) for the orbicularis oris muscle. At both time points, postoperative facial paresis correlated significantly with FMEP waveform deterioration in orbicularis oculi during final (immediate, p=0.023; follow-up, p=0.116) and in orbicularis oris during TuDis, TuRes and final (immediate, p´s=0.071, 0.000 and 0.001, respectively; follow-up, p´s=0.015, 0.001 and 0.01, respectively). FMEP amplitude ratio and waveform morphology during VS resection seem to represent independent quantitative parameters that can be used to predict postoperative facial function. Event-to-baseline FMEP monitoring is quite useful to dictate when intraoperative changes in surgical strategy are warranted to reduce chances of facial nerve injury.

Introdução. A estimulação do córtex motor (ECM) tem sido utilizada para o tratamento de pacientes com síndromes neuropáticas dolorosas crônicas e resistentes a tratamentos farmacológicos convencionais. O córtex motor primário pode ser a estrutura mais rostral do neuroeixo relacionada ao sistema de modulação da dor, e a ECM provoca ativação neuronal na substância cinzenta periaquedutal (PAG). A PAG é um dos principais centros do sistema descendente supressor de dor e recebe aferências de diferentes regiões do encéfalo. Esse estudo investiga o efeito da estimulação do córtex motor sobre a liberação de neurotransmissores na PAG em modelo de dor neuropática, com o objetivo de investigar os mecanismos neuroquímicos responsáveis pelo feito terapêutico. Métodos. No primeiro experimento, ratos Wistar machos foram aleatoriamente divididos em três grupos. No primeiro grupo, os animais foram submetidos à indução de dor neuropática através da constrição crônica do nervo ciático, no segundo grupo, os animais foram submetidos apenas à exposição do nervo ciático e no terceiro grupo, nenhuma intervenção para indução de dor neuropática foi realizada. Todos os animais foram submetidos a implante unilateral epidural de eletródios de estimulação sobre a área do córtex motor correspondente a pata posterior e implante de cânula guia direcionada à PAG utilizando coordenadas estereotáxicas. Os animais foram avaliados no teste de hiperalgesia mecânica e uma sonda de microdiálise foi introduzida em direção a PAG. As amotras de microdiálise foram coletadas e a análise dos neurotransmissores foi feita em um sistema de cromatografia líquida de alta eficiência (HPLC). No segundo experimento, ratos Wistar machos com dor neuropática induzida na pata posterior foram submetidos a implante estereotáxico de cânula guia direcionada à PAG, e foi realizada micro-injeção de antagonista de glicina e/ou GABA na PAG, previamente a ECM, para avaliar a influência desses antagonistas no efeito analgésico induzido pela estimulação cortical. Resultados. Animais submetidos à indução de dor neuropática apresentaram reversão da hiperalgesia mecânica após ECM. A estimulação cortical induziu um aumento significativo nos níveis de glicina durante (aumento de 153%) e após MCS (134%). A concentração de GABA aumentou 145% durante a estimulação epidural. Os níveis de glutamato não mostraram alteração no microdialisado da PAG após ECM. Houve uma correlação estatisticamente significativa entre o posicionamento da sonda de microdiálise nas colunas lateral e dorsolateral da PAG e o aumento na liberação do neurotransmissor glicina nos animais do grupo CCI. A administração de antagonista de glicina na PAG reverteu o efeito antinociceptivo da estimulação cortical. A micro-injeção de antagonista de GABA na PAG reverteu parcialmente o efeito da ECM. Conclusões. Nossos resultados sugerem que os neutransmissores glicina e GABA, liberados na PAG durante ECM, contribuem para o efeito antinociceptivo da via analgésica descendente. Os resultados desse projeto poderão contribuir para a elucidação dos mecanismos do efeito antinociceptivo da ECM / Introduction. Motor cortex stimulation (MCS) has been used for the treatment of patients with chronic neuropathic pain syndromes that are resistant to conventional pharmacological treatment. The motor cortex may be the most rostral structure in the neuroaxis responsible for pain modulation, and MCS increase the neuronal activation of periaqueductal gray (PAG). The PAG is one of the main subcortical centers of the descending pain suppressor system, and receives inputs from several brain areas. This study investigates the effects of MCS on the release of neurotransmitters in the PAG in neuropathic pain model, in order to investigate the possible neurochemical mechanisms responsible for this effect. Methods. In the first experiment, Wistar male rats were randomly subdivided into three surgical groups. In the first group, induction of neuropathic pain was performed through chronic constriction injury of the right sciatic nerve, in the second group, the animals were submitted just to exposure of the sciatic nerve and in the third group, no intervention for induction of neuropathic pain was performed. All the rats underwent implantation of unilateral epidural electrodes on the motor area corresponding to the right hind paw. The animals were evaluated for mechanical hyperalgesia test and a microdialysis guide cannula was stereotaxically implanted into the PAG. The microdialysate samples were collected and the neurotransmitters analysis was performed by a high- performance (HPLC). In the second experiment, animals with induced neuropathic pain in the hind paw were submitted to a stereotaxic implantation of a guidewire directed to PAG, and a microinjection of glycine and/or GABA antagonist in the PAG before the ECM was performed, to evaluate the influence of these antagonists on the analgesic effect induced by the cortical stimulation. Results. Animals subjected to induction of neuropathic pain showed reversal of mechanical hyperalgesia after motor cortex stimulation. Cortical stimulation induced a significant increase in glycine levels during (153 % increase) and after MCS (134%). The GABA concentration increases 145 % during transdural stimulation. Glutamate levels showed no change in PAG microdialysate after MCS. There was a statistically significant correlation between the positioning of the microdialysis probe in the lateral and dorsolateral columns of the PAG and the increase in the release of the neurotransmitter glycine in the animals of the CCI group. Administration of glycine antagonist in PAG reversed the antinociceptive effect of cortical stimulation. Microinjection of GABA antagonist in PAG partially reversed the effect of MCS. Conclusions. Our results suggest that the neurotransmitters glycine and GABA, released in PAG during MCS, contribute to descending antinociceptive actions. The results of this project will contribute for the elucidation of the mechanisms of the antinociceptive effect of MCS, a phenomenon that has not been fully understood currently

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-07-01T14:09:17Z No. of bitstreams: 1 lilianafajardooliveira.pdf: 1464132 bytes, checksum: cb16276286fab625982097f92dc374df (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-13T16:01:12Z (GMT) No. of bitstreams: 1 lilianafajardooliveira.pdf: 1464132 bytes, checksum: cb16276286fab625982097f92dc374df (MD5) / Made available in DSpace on 2016-07-13T16:01:12Z (GMT). No. of bitstreams: 1 lilianafajardooliveira.pdf: 1464132 bytes, checksum: cb16276286fab625982097f92dc374df (MD5) Previous issue date: 2012-03-16 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / A enurese é uma perda intermitente e involuntária de urina durante o sono. É classificada como monossintomática, quando apenas há perda urinária noturna e não-monossintomática, que além de perda noturna, ocorrem sintomas urinários durante o dia. Acredita-se que a eletroestimulação nervosa transcutânea parassacral (ENTP) tem um efeito de recondiocionamento fisiológico, possibilitando a remodulação de sinapses através da neuroplasticidade, afim de um recondicionamento neural definitivo. Seu uso em crianças com disfunção do trato urinário inferior (DTUI) é bem conhecido, entretanto, nenhum estudo avaliou seus efeitos sobre a enurese monossintomática. O objetivo do presente estudo foi avaliar a eficácia da ENTP no tratamento da na enurese primária monossintomática associada à terapia comportamental. O desenho do estudo foi um ensaio clínico controlado prospectivo. 45 pacientes, sendo 29 meninas, acima de 6 anos com enurese monossintomática primária, atendidos no ambulatório de Urologia Pediátrica do HU/CAS-UFJF foram divididos aleatoriamente em 2 grupos, controle (GC), tratado com terapia comportamental, e experimental (GE), tratado com terapia comportamental e ENTP. No GE, os eletrodos foram colocados na região sacral (S2/S3) do paciente. A sessão teve sempre o mesmo formato, com duração de 20 minutos, frequência 10Hz, largura de pulso de 700μS e intensidade determinada pelo limiar de sensibilidade da criança. Foram aplicadas 10 sessões, três vezes por semana e em dias alternados. Os pacientes de ambos os grupos foram acompanhados com intervalos de 2 semanas no primeiro mês e mensalmente por 6 meses consecutivos. O percentual de noites secas no início do tratamento foi de 23% no GC e 22% no GE (p=0,82) e ao final do tratamento passou a 51% e 69% (p=0,02) respectivamente. Na estratificação por faixa etária, o GC apresentou uma melhora significativa após a terapia comportamental, passando de 31,4% nas crianças maiores de 10 anos a 67,6% (p=0,108) e de 17,6% nas crianças com idade menor ou igual a 10 anos a 39,7% (p=0,02) após 180 dias. A avaliação por sexo demonstrou que no GE havia uma diferença estatística significativa apenas antes do tratamento (11,9% nos meninos e 27,4% nas meninas p=0,03), o que se tornou semelhante ao final do acompanhamento (63,3% e 71,9%, respectivamente p=0,39). Ao analisar o incremento de noites secas do GE em relação ao gênero, observa-se que não houve diferença significativa entre os sexos. Analisando a quantidade de noites secas em um intervalo de 30 dias, observou-se que houve um aumento significantemente maior no grupo submetido à ENTP quando comparado ao GC (14,11 ± 6,63 noites secas no GE e 8,28 ± 6,42 noites secas no GC por 30 dias p=0,0054). Quando subdividimos o grupo experimental por faixa etária (maior e menor que 10 anos), observamos que esse incremento no número de noites secas é semelhante (p=0,971), o mesmo acontece quando o GE é subdividido de acordo com sexo (p=0,312). A aplicação de ENTP por 10 sessões associada ao tratamento comportamental, apesar de não ter levado a cura, mostrou-se eficaz no tratamento da enurese monossintomática quando comparada ao tratamento comportamental. Entretanto, nenhum paciente apresentou remissão completa dos sintomas. / Nocturnal enuresis (NE) is an intermittent and involuntary loss of urine during sleep. It is classified as monosymptomatic, when only nocturnal loss of urine is present and non-monosymptomatic nocturnal, besides nocturnal loss of urine daytime lower urinary tract symptoms occur. It is believed that transcutaneous parasacral electrical stimulation (TCPSE) has a physiological recondition effect redesigning synapses by neuronal plasticity. Its use in children with lower urinary tract dysfunction is well known, however, no study has evaluated its effects on monosymptomatic nocturnal enuresis. To assess the effectiveness of TCPSE in the treatment of primary monosymptomatic enuresis. This prospective controlled clinical trial enrolled 45 children (29 girls) over 6 years of age with primary enuresis treated in the Pediatric Urology Clinic of HU/CAS-UFJF. The children were divided at random into 2 groups, control (GC), treated with behavioral therapy and experimental (GE), treated with behavioral therapy and 10 session of TCPSE. TCPSE were performed with the electrodes placed in the sacral region (S2/S3) of the patient. Sessions had always the same pattern, with 20 minutes duration, frequency of 10 Hz with a generated pulse of 700μs and intensity determined by the child's sensitivity threshold. Sessions were done three times a week on alternate days. Patients of both groups were accompanied with intervals of 2 weeks in the first month and monthly for 6 consecutive months. The percentage of dry nights at the onset of treatment was 23% in GC and 22% in GE (p = 0,82) and 51% and 69% at the end of the treatment, respectively (p = 0,02). Separating the groups in children younger and older than 10 years of age, it was observed a significant improvement in dry nights in children younger than 10 in GC (17,6 to 39.7% p=0,02) and no improvement in the group older than 10 years of age (32,4 to 67,6% - p=0,108) after 6 months follow-up. When we evaluated each gender individually we found a statistical difference in GE just before treatment (11,9% in boys and 27,4% in girls p=0,03), which became similar at the end of follow-up (63.3% and 71,9%, respectively p=0,39). Analyzing the amount of dry nights in an interval of 30 days, it was observed that there was a significantly greater increase in the group undergoing TCPSE when compared to CG (14,11 ± 6,63 dry nights in GE and 8,28 ± 6,42 dry nights in GC for 30 days p = 0.0054). Subdividing the experimental group by age (greater and less than 10 years), we observed that this increase in the number of dry nights was similar (p=0,971), and the same similarity occurred when GE was subdivided according to sex (p=0,312). Treatment of monosymptomatic enuresis with 10 sessions of TCPSE associated with behavioral treatment proved to be effective although no patient was cured after 6 months follow-up. However, no patient had complete remission of symptoms.

This study aims to evaluate the effects of functional electrical stimulation on motor and functional abilities of paretic upper limb in patients after stroke. Specifically detects the immediate effect of functional electrostimulation on the increase of the active range of motion, reduction of the hand spasticity degree and the improvement of functional performance. The research covered a total of 6 patients after first stroke in the basin aretria middle cerebral artery. The research sample had a homogeneous distribution of the paresis heaviness from light, moderate, to severe. The research was conducted in total of three weeks, every working day, 60 minutes a day, with 30 minutes of indicated electrostimulation and 30 minutes of testing of monitored parameters. Patients were evaluated using the Modified Frenchay scale, Modified Tardieu scale and the range of motion goniometer. Research showed in 60 observations that the functional electrical stimulation has immediate and significant effect on increasing the active range of dorsal flexion motion of the wrist (p-value 0.043). The average improvement on 95% interval estimation is 0.08. During the monitoring of the improvement of the active range of wrist dorsal flexion motion between input and output examination there was no statistically significant...

L’implant cochléaire (IC) est une prothèse auditive implantée dans l’oreille interne qui a pour fonction de restaurer le sens de l’audition aux personnes atteintes de surdité sévère à profonde lorsque les aides auditives classiques ne leur permettent plus une audition suffisante. Pour pouvoir transmettre les indices provenant des sons extérieurs, l’IC contourne une grande partie du système auditif défaillant et stimule directement les fibres du nerf auditif du patient. En pratique, les électrodes de l’implant émettent des trains d’impulsions électriques modulées en amplitude. Ces trains d’impulsions ont une fréquence de répétition (cadence) constante. Un problème limitant est que nous ne connaissons pas entièrement les effets physiologiques et perceptifs liés à l’augmentation de la cadence de stimulation. Le projet de recherche lié à la présente thèse s’inscrit dans l’optique d’améliorer le codage temporel des futurs ICs. Cette thèse a pour but de mieux comprendre l’influence de la cadence de la stimulation électrique sur la perception des sons avec, comme objectif fondamental, de caractériser les mécanismes physiologiques sollicités lors d’une stimulation électrique. La cadence de la stimulation affecte au moins trois dimensions perceptives distinctes qui sont la hauteur, la durée et la sonie. Les expériences s’intéressent à résoudre des problèmes précis concernant chacune de ces dimensions. Lorsque nous le pouvions, les expériences réalisées chez le sujet IC ont également été réalisées chez des sujets normo-entendants en utilisant des simulations acoustiques d’ICs. / Cochlear implants (CIs) are auditory prostheses directly inserted in the inner ear to partly restore the sense of audition to people suffering from severe to profound deafness. In order to convey environmental sounds, CIs bypass the peripheral auditory system and produce amplitude-modulated electrical pulses that stimulate auditory nerve fibres. In general, pulses are delivered with a constant frequency of occurrence (i.e. rate). Even if CI users reach good performances to understand speech, it roughly diminishes when they are placed more complex audiological environment.A potential problem is that stimulation rates are not the same among subjects while our knowledge concerning the physiological mechanisms provided by rate variations, is limited. This thesis aims to improve temporal coding of CIs by studying the perceptual influence of stimulation rate, and quantify the physiological mechanisms sought by an electrical stimulation. At least, stimulation rate acts on three perceptual dimensions which are pitch, sound duration and loudness. The present experiment solves specific problems concerning each dimension cited previously. In addition to electrical stimulations, acoustical simulations of a CI were conducted to compare normal hearing with hearing-impaired performances.

Orientadores: José Wilson Magalhães Bassani, Rosana Almada Bassani / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-26T11:22:43Z (GMT). No. of bitstreams: 1 Milan_HugoFernandoMaia_M.pdf: 2735459 bytes, checksum: 650eb9ee4f85d8ff73ae612f72ae3534 (MD5) Previous issue date: 2015 / Resumo: Tendo em vista que a estimulação com campos elétricos externos (E) é utilizada na prática clínica para tratamento de arritmias cardíacas, é necessário um melhor entendimento do fenômeno de polarização da membrana plasmática de cardiomiócitos por E. O disparo de potencial de ação, e subsequente contração celular, induzido por E em cardiomiócitos depende da indução de variação do potencial elétrico transmembrana (?Vm) que leve este potencial ao valor limiar. Devido às limitações dos métodos atualmente disponíveis para medir ?Vm e seu valor máximo, ?Vmax, os modelos eletromagnéticos representam uma importante ferramenta para sua estimativa. Porém, os valores calculados dependem de como o fenômeno de polarização da membrana é modelado. Os modelos eletromagnéticos encontrados na literatura aproximam a forma irregular do cardiomiócito a formas geométricas regulares. Entretanto, até o momento, não se sabe qual destes modelos é o mais adequado para se estimar ?Vm. As células miocárdicas apresentam irregularidades em sua forma e, tanto a forma quanto as dimensões das células alteram-se com o desenvolvimento pós-natal. Neste trabalho, foi desenvolvido um modelo numérico tridimensional (MN3D) da forma irregular da célula, e comparou-se as estimativas de ?Vm induzida por E limiar (?VL) feitas com este modelo e com modelos simplificados, entre estes o modelo numérico bidimensional (MN2D) e os modelos analíticos para cilindro (MACil), esfera (MAEsf), esferóide prolato (MAEsPr) e elipsóide (MAElip). Para estimar ?VL, E limiar e as dimensões celulares foram medidos em células cardíacas isoladas de ratos neonatos (5-7 dias), infantes (28-32 dias) e adultos (4-6 meses), em 6 faixas de ângulos entre a direção de aplicação do campo e o eixo maior da célula. Os modelos foram calibrados do ponto de vista eletromagnético, o que mostrou que, MN2D e MACil são inadequados para estimar ?Vmax. Enquanto as estimativas de ?VL com MN3D e MAEsPr não variaram com o ângulo, mas sim com a idade, o oposto ocorreu com as estimativas feitas com o MAElip. Dentro de certas condições, as estimativas de ?VL feitas com MAEsPr foram as mais próximas daquelas feitas com MN3D. Conclui-se que o MAEsPr, menos complexo tecnicamente, pode fornecer estimativas confiáveis de ?VL, desde que o ângulo de aplicação de E seja pequeno (até 30º) / Abstract: Considering that stimulation with external electrical fields (E) is clinically used for arrhythmia treatment, it is important to understand the phenomenon of membrane polarization by E. Action potential and contraction triggering by E in cardiomyocytes depends on the induction of a transmembrane potential variation (?Vm) sufficient for the attainment of the excitation threshold. Due to the limitations of the methods currently available for measurement of ?Vm and its maximum value, ?Vmax, electromagnetic models represent an important tool for this purpose. However, the calculated values depend on how the membrane polarization phenomenon is modeled. The electromagnetic models available in the literature approximate the cardiomyocyte irregular shape to regular geometries. Nevertheless, it has not been ascertained yet which model is the most appropriated to estimate ?Vmax in these cells, of which both dimensions and shape vary markedly during postnatal development, and often present geometric irregularities. Thus, approximation of the cell shape to regular geometries may result in a considerable error in the ?Vm estimation. The aim of this study was to develop a three-dimensional numerical model (MN3D) based on the irregular cell shape and to compare the values of ?Vmax induced by the threshold E (?VL) estimated with this model with those calculated with simplified models, such as the twodimensional numerical model (MN2D) and the analytical models for cylinder (MACil), sphere (MAEsf), prolate spheroid (MAEsPr), and ellipsoid (MAElip). To estimate ?VL, the threshold E and cell dimensions were measured in cardiomyocytes isolated from neonatal (5-7 days), weaning (28-32 days) and adult (4-6 months) rats, for 6 ranges of the angle between the directions of E and the cell major axis. Electromagnetic calibration of the models showed that MN2D and MACil were not suitable for ?Vmax estimation in these cells. While ?VL estimated with MN3D and MAEsPr were angle-independent, but dependent on the animal's age, the opposite was observed regarding the estimates made with MAElip. Under certain conditions, ?VL values estimated with MAEsPr were the closest to those obtained with MN3D. It is concluded that MAEsPr, a less technically complex model, can provide reliable ?VL estimates provided that the angle between the directions of E and the cell major axis is small (up to 30º) / Mestrado / Engenharia Biomedica / Mestre em Engenharia Elétrica

Submitted by Nadir Basilio (nadirsb@uninove.br) on 2016-05-25T18:06:07Z No. of bitstreams: 1 Roberta Delasta Lazzari.pdf: 2200811 bytes, checksum: 37290c6b343d6e2ca53090aceb0d4682 (MD5) / Made available in DSpace on 2016-05-25T18:06:07Z (GMT). No. of bitstreams: 1 Roberta Delasta Lazzari.pdf: 2200811 bytes, checksum: 37290c6b343d6e2ca53090aceb0d4682 (MD5) Previous issue date: 2015-02-26 / Purpose: To investigate the effects of transcranial direct current stimulation in the primary motor cortex, associated with mobility training with virtual reality on the static and functional balance of children with cerebral palsy (CP). Materials and Methods: The population sample that was part of this project consisted of 24 children with CP between 4 and 12 years old. The children were divided randomly into two groups (control group: mobility training with virtual reality and use transcranial stimulation placebo; Experimental Group: mobility training using virtual reality and transcranial stimulation active) and evaluated at four different times (pre -intervention, immediately after the first session, after the intervention and one month after intervention). The static balance was evaluated by force platform in four conditions: feet flat on the platform with open eyes, feet on the platform with eyes closed, feet in the open foam eyes, feet foam eyes closed for 30 seconds each. The Functional Balance was measured by Pediatric Balance Scale(PBS) and Timed Up and Go(TUG). Results: The analysis of the immediate effect of treatment with transcranial Direct Current Stimulation (tDCS) only sway velocity showed a significant interaction. In the analysis of the effects of the training area, Center of Pressure (COP) speed and frequency presented significatia interaction as well as the EEP and TUG Conclusion: It is suggested that tDCS interferes with the static and functional balance of children with CP. / Objetivo: Verificar os efeitos da estimulação transcraniana por corrente contínua no córtex motor primário, associada ao treino mobilidade com realidade virtual sobre o equilíbrio estático e funcional de crianças com paralisia cerebral (PC). Materiais e Métodos: A amostra populacional que fez parte deste projeto foi composta de 24 crianças com PC entre 4 e 12 anos de idade. As crianças foram alocadas aleatoriamente em dois grupos (Grupo Controle: treino de mobilidade com uso de realidade virtual e estimulação transcraniana placebo; Grupo Experimental: treino de mobilidade com o uso de realidade virtual e estimulação transcraniana ativa) e avaliadas em quatro momentos distintos (pré-intervenção,imediatamente após a primeira sessão, pós-intervenção e um mês após as intervenções). O equilíbrio estático foi avaliado através da plataforma de força em quatro condições: pés apoiados na plataforma com olhos abertos, pés na plataforma com olhos fechados, pés na espuma olhos abertos, pés espuma olhos fechados, por 30 segundos cada. O Equilíbrio Funcional foi medido por meio da Escala de Equilíbrio Pediátrica (EEP) e Timed Up and Go (TUG). Resultados: Na Análise do Efeito imediato do tratamento com Estimulação Transcraniana por Corrente Contínua(ETCC) somente a velocidade de oscilação apresentou interação significativa. Já na análise dos efeitos do Treinamento a área, velocidade e frequência do Centro de Pressão (CoP) apresentaram interação significatia, bem como o EEP e TUG Conclusão: Sugere-se que a ETCC interfere sobre o equilíbrio estático e funcional de crianças com PC.

La pratique d’exercices intenses répétés, entrecoupés de faibles temps de récupération, est susceptible d’engendrer une altération de l’homéostasie et une diminution de la performance chez les sportifs soumis à ce type de contraintes. Dans ce contexte, l’optimisation des processus de récupération est une possibilité forte d’amélioration de la performance et de sa reproduction. Une des principales limites au maintien de la performance de type haute intensité, répété à court terme, est attribuée à la fatigue périphérique, inhérente à l’ensemble des mécanismes de l’excitabilité et de la contraction du muscle squelettique. Cette fatigue périphérique engendre une inadéquation entre les apports et les besoins cellulaires, en oxygène et en nutriments, ainsi qu’une incapacité à éliminer et/ou recycler les produits métaboliques issus de la contraction musculaire. Afin de limiter ces effets, l’augmentation du flux sanguin lors de l’exercice et de la récupération apparaît indispensable au bon rétablissement de l’état d’équilibre de l’organisme et au maintien de la performance sportive. A ce titre, l’électrostimulation neuromusculaire semble être un mode de récupération théoriquement efficace pour augmenter le flux sanguin. Cette présente thèse, comprenant trois études, visait à connaître précisément les effets de l’électrostimulation neuromusculaire - par l’utilisation d’un nouvel appareil issu du domaine médicale - sur la cinétique de récupération de marqueurs de performance, de marqueurs physiologiques et de perception, dans le contexte d’exercices intenses, répétés à court terme. Nous avons émis l’hypothèse qu’une stimulation efficace, induisant une augmentation du flux sanguin, permettrait d’optimiser la récupération à court terme, entre deux exercices de haute intensité. Ces résultats devraient permettre d’optimiser, dans le futur, les stratégies de récupération mises en place après un exercice intense, répété dans de brefs délais / The practice of intense and repeated exercises, interrupted with short recovery times, may induce alterations in homeostasis and a decrease of the performance for athletes who are subject to this type of constraints. In this context, the optimization of the recovery processes is a strong possibility to improve performance and the maintain of it all along the competitive period. One of the main limits in the preservation of performance in type high-intensity, repeated at small interval of time, is attributed to the peripheral fatigue, inherent to all the mechanisms implied in the skeletal muscle excitability and contraction. This peripheral fatigue induces an inadequacy between the contributions and the cellular needs of oxygen and nutrients, and also a disability for disposal or recycling the metabolic by-products stemming from the muscular contraction. In order to limit these effects, the increase in blood flow during exercise and recovery seems essential for the good restoring of the state of physiological balance for the body and the preservation of sport performance. Therefore, the neuromuscular electrical stimulation seems to be, in theory, an effective recovery mode to improve the blood flow. This present thesis, comprising three studies, aimed to know precisely the effects of the neuromuscular electrical stimulation - by the use of a new device stemming from the medical field - on the kinetics of recovery of performance, physiological and perceptual markers, in the context of intense exercises repeated in the short terms. We hypothesized that an effective stimulation, increasing the blood flow would allow to optimize short-term recovery between two high-intensity exercises. These results should contribute to optimize, in the future, the strategies of recovery organized after an intense exercise

Background: Vagus nerve stimulation is increasingly applied to treat epilepsy, psychiatric conditions and potentially chronic heart failure. After implanting vagus nerve electrodes to the cervical vagus nerve, side effects such as voice alterations and dyspnea or missing therapeutic effects are observed at different frequencies. Cervical vagus nerve branching might partly be responsible for these effects. However, vagus nerve branching has not yet been described in the context of vagus nerve stimulation. Materials and methods: Branching of the cervical vagus nerve was investigated macroscopically in 35 body donors (66 cervical sides) in the carotid sheath. After X-ray imaging for determining the vertebral levels of cervical vagus nerve branching, samples were removed to confirm histologically the nerve and to calculate cervical vagus nerve diameters and cross-sections. Results: Cervical vagus nerve branching was observed in 29%of all cases (26% unilaterally, 3% bilaterally) and proven histologically in all cases. Right-sided branching (22%) was more common than left-sided branching (12%) and occurred on the level of the fourth and fifth vertebra on the left and on the level of the second to fifth vertebra on the right side. Vagus nerves without branching were significantly larger than vagus nerves with branches, concerning their diameters (4.79mm vs. 3.78mm) and cross-sections (7.24 mm2 vs. 5.28mm2). Discussion: Cervical vagus nerve branching is considerably more frequent than described previously. The side-dependent differences of vagus nerve branching may be linked to the asymmetric effects of the vagus nerve. Cervical vagus nerve branching should be taken into account when identifying main trunk of the vagus nerve for implanting electrodes to minimize potential side effects or lacking therapeutic benefits of vagus nerve stimulation.

<div>Cochlear implants (CI) are sensory neuroprostheses capable of partially restoring hearing loss by electrically stimulating the auditory nerve to mimic normal hearing conditions. Despite their success and ongoing advances in both hardware and software, CI patients can still struggle to understand speech, most notably in complex auditory settings, also referred to as the cocktail party problem. Efforts to develop new CI algorithms to overcome this challenge rely on CI simulators and vocoders to test with normal hearing (NH) patients. However, recent studies have suggested that these tools fail to reproduce the stimuli perceived by CI patients. It is therefore critical to develop tools capable of producing better representations of the stimuli as perceived by CI patients. Thus, this work proposes a framework that incorporates physiological models of the peripheral auditory nerve. Using these models, the framework generates stimulations that elicit a neural response at the auditory nerve closer to that observed in NH conditions. Stimulations generated by the framework were evaluated by performing a vowel identification task. However, the task was performed by a classifier trained using deep learning techniques instead of a CI patient. These results give insight into how the framework could be applied for the development and validation of CI stimulation strategies.</div>