Distúrbios do sistema nervoso central (SNC) em ruminantes abrangem um importante grupo de enfermidades responsáveis por grandes perdas econômicas em todo o mundo. As principais doenças neurológicas causadas por bactérias em ruminantes e que envolvem processos inflamatórios incluem listeriose, leptomeningites e meningoencefalites supurativas, abscessos cerebrais e medulares, empiema basilar e neurotuberculose. Esta dissertação teve por objetivo a caracterização epidemiológica, patológica, microbiológica e imuno-histoquímica das doenças inflamatórias de origem bacteriana que afetam o SNC de ruminantes no Rio Grande do Sul. Foi realizado um estudo retrospectivo no período compreendido entre janeiro de 1996 a dezembro de 2015, onde um total de 3.274 bovinos, 596 ovinos e 391 caprinos foram avaliados. Destes, 219 bovinos, 21 ovinos e sete caprinos foram diagnosticados com doenças inflamatórias no SNC. As doenças neurológicas inflamatórias de origem bacteriana totalizaram 60 casos divididos em 34 bovinos, 19 ovinos e sete caprinos, os quais foram subdivididas em: meningoencefalite por L. monocytogenes (oito ovinos, cinco caprinos e quatro bovinos), leptomeningite e meningoencefalite supurativa (14 bovinos, dois caprinos e um ovino), abscessos cerebrais (seis bovinos e dois ovinos) e medulares (sete ovinos), empiema basilar (quatro bovinos e um ovino) e neurotuberculose (seis bovinos). O exame imuno-histoquímica foi realizado em todos os casos diagnosticados com listeriose (anticorpo anti-L. monocytogenes), meningite e meningoencefalite supurativa (anticorpo anti-Escherichia coli) e neurotuberculose (anticorpo anti-Mycobacterium tuberculosis). A meningoencefalite por L. monocytogenes representou a principal enfermidade neurológica em ovinos e caprinos, seguido dos abscessos medulares em ovinos. Nos bovinos, a leptomeningite e meningoencefalite supurativa foi a doença neurológica mais prevalente para a espécie, frequentemente relacionada com a falha na transmissão da imunidade passiva. O empiema basilar, frequentemente diagnosticado em bezerros, está diretamente relacionado com o manejo do desmame interrompido através da utilização de tabuletas nasais. A neurotuberculose causada por Mycobacterium spp. é uma importante doença neurológica em bovinos jovens e deve ser considerada como diagnóstico diferencial de doenças neurológicas. Dos dados analisados neste período, as doenças neurológicas inflamatórias bacterianas representaram um total de 24,3% entre as doenças neurológicas inflamatórias diagnosticadas neste período e, com isso, conclui-se que representam importantes causas de mortalidade para os ruminantes domésticos. / Central nervous system (CNS) diseases are worldwide economically important conditions in ruminants. The main neurological bacterial diseases which involve inflammation in ruminants are listeriosis, suppurative leptomeningitis and meningoencephalitis, brain and spinal cord abscesses, basilar empyema and neurotuberculosis. This study aim to describe the epidemiological, pathological, microbiological and immunohistochemical findings of the bacterial inflammatory diseases that affect the CNS of ruminants in Rio Grande do Sul state. A retrospective study was performed from January 1996 to December 2015, during which samples of 3.274 cattle, 596 sheep and 391 goats were evaluated. Of these, 219 cattle, 21 sheep and seven goats were diagnosed with inflammatory diseases affecting the CNS. The neurological inflammatory bacterial diseases accounted for 60 cases, which corresponded to 34 cases in cattle, 19 in sheep and seven in goats. These were further subdivided in: meningoencephalitis by L. monocytogenes (eigth sheep, five goats and four cattle), suppurative leptomeningitis and meningoencephalitis (14 cattle, two goats and one sheep), brain abscesses (six cattle and two sheep) and spinal cord (seven sheep), basilar empyema (four cattle and one sheep) and neurotuberculosis (six cattle). Immunohistochemical exam was performed in all cases diagnosed as listeriosis (antibody anti-L. monocytogenes), as suppurative leptomeningitis and meningoencephalitis (antibody anti-E. coli), and as neurotuberculosis (antibody anti-Mycobacterium tuberculosis). L. monocytogenes meningoencephalitis was the main neurological disease in sheep and goats, followed by spinal cord abscesses in sheep. In cattle, suppurative leptomeningitis and meningoencephalitis was the most frequent neurological disease, and its ocorrunce is related to the failure in passive immunity transmission. Basilar empyema is frequently diagnosed in calves and is directly related to early weaning handling through the use of nose-flaps. Neurotuberculosis caused by Mycobacterium spp. is an important neurological disease in young cattle and should be consired as a differential diagnosis of granulomatous meningoencephalitis. During the described period, neurological inflammatory bacterial diseases accounted for 24.3% of the neurological inflammatory diseases, and, thus, these are important causes of death in domestic ruminants.

Distúrbios do sistema nervoso central (SNC) em ruminantes abrangem um importante grupo de enfermidades responsáveis por grandes perdas econômicas em todo o mundo. As principais doenças neurológicas causadas por bactérias em ruminantes e que envolvem processos inflamatórios incluem listeriose, leptomeningites e meningoencefalites supurativas, abscessos cerebrais e medulares, empiema basilar e neurotuberculose. Esta dissertação teve por objetivo a caracterização epidemiológica, patológica, microbiológica e imuno-histoquímica das doenças inflamatórias de origem bacteriana que afetam o SNC de ruminantes no Rio Grande do Sul. Foi realizado um estudo retrospectivo no período compreendido entre janeiro de 1996 a dezembro de 2015, onde um total de 3.274 bovinos, 596 ovinos e 391 caprinos foram avaliados. Destes, 219 bovinos, 21 ovinos e sete caprinos foram diagnosticados com doenças inflamatórias no SNC. As doenças neurológicas inflamatórias de origem bacteriana totalizaram 60 casos divididos em 34 bovinos, 19 ovinos e sete caprinos, os quais foram subdivididas em: meningoencefalite por L. monocytogenes (oito ovinos, cinco caprinos e quatro bovinos), leptomeningite e meningoencefalite supurativa (14 bovinos, dois caprinos e um ovino), abscessos cerebrais (seis bovinos e dois ovinos) e medulares (sete ovinos), empiema basilar (quatro bovinos e um ovino) e neurotuberculose (seis bovinos). O exame imuno-histoquímica foi realizado em todos os casos diagnosticados com listeriose (anticorpo anti-L. monocytogenes), meningite e meningoencefalite supurativa (anticorpo anti-Escherichia coli) e neurotuberculose (anticorpo anti-Mycobacterium tuberculosis). A meningoencefalite por L. monocytogenes representou a principal enfermidade neurológica em ovinos e caprinos, seguido dos abscessos medulares em ovinos. Nos bovinos, a leptomeningite e meningoencefalite supurativa foi a doença neurológica mais prevalente para a espécie, frequentemente relacionada com a falha na transmissão da imunidade passiva. O empiema basilar, frequentemente diagnosticado em bezerros, está diretamente relacionado com o manejo do desmame interrompido através da utilização de tabuletas nasais. A neurotuberculose causada por Mycobacterium spp. é uma importante doença neurológica em bovinos jovens e deve ser considerada como diagnóstico diferencial de doenças neurológicas. Dos dados analisados neste período, as doenças neurológicas inflamatórias bacterianas representaram um total de 24,3% entre as doenças neurológicas inflamatórias diagnosticadas neste período e, com isso, conclui-se que representam importantes causas de mortalidade para os ruminantes domésticos. / Central nervous system (CNS) diseases are worldwide economically important conditions in ruminants. The main neurological bacterial diseases which involve inflammation in ruminants are listeriosis, suppurative leptomeningitis and meningoencephalitis, brain and spinal cord abscesses, basilar empyema and neurotuberculosis. This study aim to describe the epidemiological, pathological, microbiological and immunohistochemical findings of the bacterial inflammatory diseases that affect the CNS of ruminants in Rio Grande do Sul state. A retrospective study was performed from January 1996 to December 2015, during which samples of 3.274 cattle, 596 sheep and 391 goats were evaluated. Of these, 219 cattle, 21 sheep and seven goats were diagnosed with inflammatory diseases affecting the CNS. The neurological inflammatory bacterial diseases accounted for 60 cases, which corresponded to 34 cases in cattle, 19 in sheep and seven in goats. These were further subdivided in: meningoencephalitis by L. monocytogenes (eigth sheep, five goats and four cattle), suppurative leptomeningitis and meningoencephalitis (14 cattle, two goats and one sheep), brain abscesses (six cattle and two sheep) and spinal cord (seven sheep), basilar empyema (four cattle and one sheep) and neurotuberculosis (six cattle). Immunohistochemical exam was performed in all cases diagnosed as listeriosis (antibody anti-L. monocytogenes), as suppurative leptomeningitis and meningoencephalitis (antibody anti-E. coli), and as neurotuberculosis (antibody anti-Mycobacterium tuberculosis). L. monocytogenes meningoencephalitis was the main neurological disease in sheep and goats, followed by spinal cord abscesses in sheep. In cattle, suppurative leptomeningitis and meningoencephalitis was the most frequent neurological disease, and its ocorrunce is related to the failure in passive immunity transmission. Basilar empyema is frequently diagnosed in calves and is directly related to early weaning handling through the use of nose-flaps. Neurotuberculosis caused by Mycobacterium spp. is an important neurological disease in young cattle and should be consired as a differential diagnosis of granulomatous meningoencephalitis. During the described period, neurological inflammatory bacterial diseases accounted for 24.3% of the neurological inflammatory diseases, and, thus, these are important causes of death in domestic ruminants.

O objetivo deste estudo foi descrever as características demográficas, clínicas, radiológicas e o prognóstico da doença oclusiva da artéria basilar (DOAB), em uma população multiétnica. Foram estudados 40 indivíduos com infartos no território da artéria basilar (AB) confirmados por ressonância magnética, que sobreviveram após 30 dias à fase aguda do acidente vascular cerebral isquêmico (AVCI). Todos os doentes apresentavam estenose ³ 50% ou oclusão da AB, documentada por angiografia por ressonância ou angiografia digital. Foram registrados: idade, sexo, grupo étnico, fatores de risco para doença vascular, quadro clínico na instalação do AVCI, local do infarto, segmento arterial acometido, grau de estenose e presença de circulação colateral. A escala modificada de Rankin (EMR) em 30 dias e após seis meses do evento isquêmico foi avaliada, assim como a taxa de recorrência de eventos vasculares isquêmicos. Associações entre dados demográficos, aspectos clínicos, radiológicos e prognóstico foram analisadas pelo teste da razão de verossimilhança ou pelo teste exato de Fisher. A comparação entre a pontuação na EMR em 30 dias e seis meses foi realizada pelo teste de Wilcoxon. Sessenta por cento dos pacientes eram homens e 33%, afro-brasileiros. A média (± desvio-padrão) de idade foi 55,8 ± 12,9 anos. A maioria (90%) dos pacientes apresentou múltiplos fatores de risco para doença vascular. Ataques isquêmicos transitórios (AIT) precederam os AVCIs em 48% dos casos. Antecedente de hipertensão arterial sistêmica (HAS) esteve presente em 80% dos doentes. O sintoma mais comum foi vertigem/desequilíbrio. A maioria dos infartos localizou-se na ponte (85%) e o terço médio da AB foi o mais freqüentemente afetado (33%). Oclusão arterial esteve presente em 58% dos casos. Lesões mais graves foram observadas em caso de acometimento do terço médio da AB (p=0,001). Aterosclerose de grandes artérias foi a etiologia mais comum do AVCI (88%), sendo mais freqüente nos pacientes acima de 45 anos (p<0,001). Somente um paciente foi tratado com trombólise intra-arterial e a maioria foi tratada com anticoagulação na fase aguda. A pontuação na EMR melhorou significativamente após seis meses (p<0,001). Podemos concluir que obtivemos alguns resultados diferentes de outras séries de países desenvolvidos, como maior proporção de afrodescendentes e oclusão da AB em pouco mais da metade dos casos. Taxas de AIT precedendo o AVCI, freqüência alta de aterosclerose como etiologia e bom prognóstico funcional foram semelhantes a descrições da literatura. Estes resultados representam um avanço no conhecimento da DOAB em nosso meio / The aim of this study was to describe demographical, clinical, radiological findings and outcome in stroke survivors with basilar artery occlusive disease (BAOC). We studied 40 patients with infarcts in the basilar artery (BA) territory confirmed by magnetic resonance imaging (MRI), who survived for at least 30 days after acute stroke. All patients had ³ 50% BA stenosis or occlusion, documented by magnetic resonance or digital subtraction angiography. The following characteristics were registered: age, sex, ethnical group, vascular risk factors, symptoms and signs, infarct location, site and degree of BA stenosis, and presence of collateral circulation. Modified Rankin Scale (MRS) scores at 30 days and six months after the ischemic event were evaluated, as well as transient ischemic attack (TIA) and stroke recurrence rates. Associations between demographical, clinical, radiological features and outcome were analyzed with Likelihoodratio and Fisher´s exact tests. The comparison between MRS scores at 30 days and six months was made with the Wilcoxon test. Sixty percent of the patients were male and 33% were Afro-Brazilian. Mean age was 55.8 ± 12.9 years. Most of the subjects (90%) had multiple vascular risk factors. TIAs preceded strokes in 48% of the patients. Eighty per cent had history of arterial hypertension. The most common neurological symptom was vertigo/dizziness. Most of the infarcts were located in the pons (85%) and the BA middle third was the most frequently affected segment (33%). BA occlusion occurred in 58% of the patients. More severe lesions were present in patients with occlusive disease in the middle third of the BA (p=0.001). Large-artery atherosclerosis was the most common stroke etiology (88%) and was more frequent in patients older than 45 years (p<0.001). Only one patient was treated with intra-arterial thrombolysis and most of the others received anticoagulation. MRS scores improved significantly at six months (p<0.001). In conclusion, we observed different results compared with other series, such as: greater proportion of afrodescendents, higher frequency of atherosclerosis and BA occlusion. Rates of preceding TIAs and good outcome at six months were similar to previously published data. These results represent a step forward towards understanding BAOC in a large Brazilian urban center

This thesis aims to verify the function of the cochlea as a spectrum analyzer based on computational modeling of macro-mechanics of the cochlea using FEM. I aim to identify the spectrum of the basilar membrane, which is dependent on the variability of geometry, material characteristics and the presence of liquid environments. Interactions between liquid and solid phases is described by fluid-structure interaction in the system ANSYS. The model is linear and does not pursue an active policy of metabolic processes. Further the work focuses on the decomposition of the sound and check of two best known hypotheses about the transmission frequency of the sound to the brain.

Différents éléments vasculo-nerveux participent à la constitution de l'angle ponto-cérébelleux. Dans certaines conditions pathologiques dont la genèse est encore imparfaitement connue actuellement, des conflits peuvent apparaître entre des vaisseaux battants autour du tronc cérébral et des nerfs crâniens. L'objectif de ce travail en trois parties distinctes est consacré à certaines bases anatomiques et physiologiques permettant de mieux appréhender ces conflits vasculo-nerveux. La première partie s'intéresse à la morphogenèse du système vertébrobasilaire. La conception d'un logiciel original de reconstruction tridimensionnelle a permis la modélisation de quatre embryons à partir de coupes histologiques. Les images obtenues permettent de confirmer la morphogenèse décrite dans la littérature et jette les bases d'une étude plus exhaustive. La deuxième partie démontre pour la première fois la mobilité physiologique du nerf vestibulo-cochléaire au niveau de l'angle ponto-cérébelleux, par l'utilisation d'une séquence IRM en contraste de phase. Les directions crânio-caudale et antéro-postérieure et leur amplitude ont été étudiées. Ces mouvements sont dépendants de l'onde de pouls. De façon plus générale, ils peuvent être modélisés sous la forme d'une corde oscillant entre le tronc cérébral et le fond du méat acoustique interne. La troisième partie traite d'une étude de faisabilité qui jette les bases informatiques permettant d'apprécier le vieillissement artériel par la variabilité morphologique du point de confluence des artères vertébrales. Au laboratoire, nous avons conçu un programme de normalisation à partir des scanographies de neuf patients. Il autorise ainsi la création d'un tronc cérébral moyen, et la comparaison de la topographie de ces points de confluence. / Several vascular and nervous structures are located within the cerebello-pontine angle. In certain pathological conditions, microvascular compression syndroms may occur, where an artery or a vein is compressing a cranial nerve. The purpose of this work in three parts is to investigate some anatomical and physiological bases of these microvascular compression syndroms. The first part focuses on the vertebrobasilar system morphogenesis. A special designed 3D reconstruction original software allowed us to reformate four human embryos from histological serial sections. The three-dimensional views are confirming the classical features thus creating the basis of a larger study based on multiple embryos. The second part shows for the first time the physiological motion of the vestibulo-cochlear nerve at the level of the cerebello-pontine angle, with the help of a phase-contrast MRI sequence. The cranio-caudal and antero-posterior directions and their amplitudes have been studied. These motions are cardiac-cycle-dependant. We used an "oscillating string" model to explain the VCN motion between the brain stem and the fundus of the internal acoustic meatus. The third part of this work is focused on a preliminary study of the variability of the vertebro-basilar arterial fusion along the lifetime. An original software has been designed and allowing the normalisation from nine post-contrast cerebral CT scanners. A ?mean? brain stem was obtained and visualized in front of nine arterial fusion points.