Introdução: a epilepsia reflexa é uma condição na qual todas as crises são desencadeadas por um estímulo específico e, na grande maioria dos casos, apresenta-se com crises refratárias ao tratamento. São vários os fatores desencadeantes, entre os quais se destaca pela raridade a evacuação. Objetivos: realizar revisão de literatura sobre epilepsia reflexa, identificar a evacuação como possível fator desencadeador de crise epiléptica e relatar o caso de um paciente com crise reflexa evacuatória documentada à monitorização por vídeo-eletroencefalograma Métodos: revisão de literatura acerca de epilepsias reflexas e revisão de prontuário de um paciente com suspeita clínica de epilepsia reflexa evacuatória. Resultados: o paciente deste estudo, um menino de 10 anos de idade, com dominância manual esquerda, iniciou, aos 4 anos, crises associadas à evacuação. Na monitorização por vídeo-eletroencefalograma, durante episódio de evacuação, apresentou parada comportamental, desvio cefálico para a direita, automatismos em membro superior esquerdo e arresponsividade, coçando o nariz tardiamente com a mão esquerda. O EEG ictal demonstrou atividade rítmica teta em região temporal esquerda com posterior envolvimento frontal esquerdo e de áreas homólogas contralaterais. As ressonâncias magnéticas de encéfalo não evidenciaram alterações e o SPECT interictal identificou hipoperfusão discreta na porção anterior do lobo temporal esquerdo. Com uso de ácido valpróico e carbamazepina o paciente segue livre de crises. Avaliações neuropsicológicas e de qualidade de vida sugerem comprometimento global, tanto antes como após o controle da epilepsia. Conclusão: este é apenas o terceiro caso de epilepsia reflexa evacuatória descrito na literatura, e o segundo com crises dessa ordem documentadas por vídeo-eletroencefalograma. Ambos sugeriram lateralização e localização em região temporal esquerda, elegendo esta região como potencial zona epileptogênica. O tratamento com ácido valpróico e carbamazepina mostrou-se eficaz para controle de crises neste paciente, podendo ser uma opção de tratamento em outros pacientes com este tipo de epilepsia. / Background: Reflex epilepsy is a condition in which all seizures are triggered by a specific stimulus. There are many known stimulus, including defecation which has rarely been reported. In the majority of cases, it presents with refractory seizures. Objective: review the literature on reflex epilepsy, as well as identify defecation as a possible trigger and report a case of a patient with reflex seizures triggered by defecation documented by video-electroencephalogram monitoring. Methods: literature review on reflex epilepsies and review of medical records of a patient with reflex epilepsy triggered by defecation. Results: we present a 10-year-old-boy patient, left-handed, whose epilepsy onset was at the age of four. Its seizures were characterized by episodes of loss of consciousness and atonia during defecation. Video-electroencephalogram monitoring had shown a seizure triggered by defecation, characterized by right head deviation, left upper limb automatisms, associated with consciousness impairment and afterwards nose wiping with the left hand. The ictal EEG demonstrated theta rhythmic activity in the left temporal lobe. The brain magnetic resonance was normal. The interictal SPECT identified left anterior temporal lobe mild hypoperfusion. The patient became seizure free after the treatment with valproic acid and carbamazepine. Neuropsychological and quality of life assessments suggested global impairment, before and after seizure control. Conclusion: this is the third case of epilepsy induced by defecation, and the second with seizures documented by videoelectroencephalogram. Similar to this case, both had suggested lateralization and localization over the left temporal region, suggesting this region as a potential epileptogenic zone in patients with this type of reflex epilepsy. In our patient, the treatment with valproic acid and carbamazepine was effective for the seizure control and may be an option to other patients with this condition.

Pacientes com epilepsia do lobo temporal farmacorresistente, frequentemente, possuem esclerose hipocampal como lesão epileptogênica. Muitas vezes, estes pacientes se beneficiam de lobectomia temporal para redução da ocorrência de crises epilépticas. Para que possam se submeter a este procedimento, é necessário o uso da videoeletroencefalografia prolongada para delimitação apurada da zona epileptogênica. Apesar dos avanços dos métodos diagnósticos nesta área, a busca por um instrumento que permita uma avaliação clara da chance de uma vida livre de crises após cirurgia permanece. No presente trabalho, a apresentação do padrão eletroencefalográfico ictal foi estudado, de forma a se pesquisar se existe relação entre a sua ocorrência e permanência em apenas um hemisfério cerebral com um melhor prognóstico pós-cirúrgico. Foram revisados os dados eletroencefalográficos ictais e os prontuários médicos de 284 pacientes. Procedeu-se à classificação de seus padrões eletroencefalográficos ictais em unilaterais ou bilaterais, e seu prognóstico após um, dois e cinco anos após cirurgia em livre de crise ou não livre de crise epiléptica. Apresentavam padrão unilateral 132 pacientes, e 152 apresentavam padrão bilateral. Estavam livres de crises 236 pacientes, e 48 ainda persistiam com crises epilépticas após cirurgia. Não houve associação entre padrões ictais unilaterais e uma vida livre de crises epilépticas após a cirurgia (diferença de 7,5%; p=0,092; chi-quadrado). Dessa forma, não se pode aplicar o padrão ictal eletroencefalográfico como ferramenta para predição de uma vida livre de crises após lobectomia temporal em pacientes com epilepsia da região mesial do lobo temporal associada à esclerose hipocampal. / Patients with drug-resistant temporal lobe epilepsy usually have hippocampal sclerosis as an epileptogenic lesion. Most of the times, these patients are benefited from temporal lobectomy for seizure relief. For this procedure to occur, a long-term videoelectroencephalogram is necessary for the accurate delineation of the epileptogenic zone. Despite the developments in the diagnostic methods on this area, the quest continues for an instrument that allows a clear evaluation of the chance to obtain a seizure-free life after epilepsy surgery. In the present study, the electroencephalographic ictal patterns were evaluated, and the relationship between its occurrence and permanence in one cerebral hemisphere and the possibility of a seizure-free outcome after surgery were compared. The ictal electroencephalografic and medical records of 284 patients were analyzed. A classification of ictal patterns, whether unilateral or bilateral, was issued, and the seizure outcome after one, two, and five years after surgery annotated. Unilateral ictal patterns occurred in 132 patients, and bilateral ictal patterns in 152. Seizure-free status was obtained in 236 patients, and 48 still persisted with seizures. There was no association between a unilateral ictal status and a seizure-free outcome after surgery (difference of 7.5%, p=0.092; chi-square). So, the electroencephalographic ictal pattern is not a valuable tool for predictions regarding seizure outcome in patients with mesial temporal lobe epilepsy associated with hippocampal sclerosis that are submitted to temporal lobectomy.

Orientadores: Lília Freire Rodrigues de Souza Li, Marcelo Ananias Teocchi / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T06:18:40Z (GMT). No. of bitstreams: 1 Ferreira_AnaErikaDias_M.pdf: 2703005 bytes, checksum: 3e71e1e36f3b90f6651557533137b593 (MD5) Previous issue date: 2014 / Resumo: Epilepsia do lobo temporal (ELT) é a forma mais comum de epilepsia em adultos. O processo de epileptogênese inclui a morte neuronal, brotamento axonal, inflamação, neurogênese, estresse oxidativo e gliose. No entanto, os mecanismos moleculares subjacentes não são totalmente compreendidos. Os fatores de crescimento de fibroblastos (FGFs) são uma família de proteínas com várias funções no organismo, especialmente no sistema nervoso central. No entanto, o funcionamento dos FGFs no cérebro humano não é totalmente compreendido. O FGF2 é o membro mais estudado dessa família e seu papel na fisiopatologia da epilepsia é controversa. Na tentativa de esclarecer o envolvimento da via de FGF na ELT, nós quantificamos a expressão hipocampal dos seguintes genes: FGF2, FGF8, FGF22, FGFR1, FGFR2, FGFR3, ITPR3, PIK3R3 e PIK3R5 em 10 pacientes resistentes a fármacos e quatro controles post mortem. Além disso, avaliamos a expressão da proteína de FGF2 por imunofluorescência indireta. Apenas para o FGF2, houve aumento do RNAm no hipocampo dos pacientes para os dois genes de referência testados, HPRT1 e ENO2 + TBP em combinação (P = 0,002 e P = 0,036; respectivamente). A porcentagem de células imunomarcadas para FGF2 no giro dentado foi maior nos pacientes do que nos controles (P <0,05), mas nenhuma alteração significativa foi encontrada no Corno de Ammon. O FGF2 pode preservar os neurônios após lesão e atua como um poderoso fator para a proliferação de células-tronco neurais. Assim, o FGF2 poderia aliviar os danos induzidos pelas crises, intensificar a reparação e reduzir a epileptogênese no hipocampo. Por outro lado, evidências têm demonstrado o envolvimento do FGF2 em mecanismos epileptogênicos, como brotamento de fibras musgosas e neurogênese. Nossos resultados sugerem a participação do FGF2 na fisiopatologia da ELT e o indica como um importante alvo para estudos farmacológicos / Abstract: Temporal lobe epilepsy (TLE) is the most common form of epilepsy in adults. The process of epileptogenesis includes neuronal death, axonal sprouting, inflammation, neurogenesis, oxidative stress and gliosis. However, the molecular mechanisms behind them are not fully understood. Fibroblast growth factor (FGF) gene family encodes proteins with several functions in the organism, especially in the central nervous system. FGF family member functions in the human brain are unclear. To shed light on the involvement of the FGF pathway in TLE, we quantified the hippocampal expression of the following genes: FGF2, FGF8, FGF22, FGFR1, FGFR2, FGFR3, ITPR3, PIK3R3 and PIK3R5 in 10 pharmacoresistant patients and four post mortem controls. We also assessed the FGF2 protein expression by indirect immunofluorescence. Only for FGF2, was the mRNA level markedly increased in patients¿ hippocampi for the two reference genes tested, HPRT1 and ENO2+TBP in combination (P = 0.002 and P = 0.036, respectively). The percentage of FGF2 immunostained cells in the dentate gyrus was higher in patients than in the controls (P <0.05), but no significant alteration was found in the Ammon¿s horn. FGF2 preserves neurons from ongoing injury and acts as a powerful proliferation factor for neural stem cells. It could potentially alleviate seizure-induced damage and intensify repair and reduce epileptogenesis in the hippocampus. On the other hand, evidence has shown FGF2¿s involvement in epileptogenic mechanisms, such as axonal sprouting and neurogenesis. Our results clearly suggest the FGF2 participation in TLE physiopathology and point it out as an important target for pharmacological studies / Mestrado / Saude da Criança e do Adolescente / Mestra em Ciências

Orientadores: Iscia Teresinha Lopes Cendes, Vinicius D'Ávila Bitencourt Pascoal / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-22T15:13:21Z (GMT). No. of bitstreams: 1 Matos_AlexandreHilarioBerenguerde_M.pdf: 2928972 bytes, checksum: d4db9f154891dd3379d9e02aacc7279f (MD5) Previous issue date: 2013 / Resumo: Wistar audiogenic rat (WAR) é um modelo genético de epilepsia de crises audiogênicas desencadeadas após alta intensidade de estimulação sonora. Outro modelo genético recentemente identificado é o da epilepsia generalizada com crises de ausência (GEAS). O objetivo do presente estudo foi caracterizar o perfil de expressão gênica destas duas cepas através de uma análise em larga escala. Para os estudos de expressão foi utilizada inicialmente a tecnologia de microarranjos seguida da validação dos resultados por técnica quantitativa de PCR em tempo real. Os resultados foram analisados em ambiente R, utilizando os pacotes AFFY e RankProd do bioconductor, utilizando o algoritmo MAS 5 os array foram normalizados e calculou-se a intensidade do sinal e a detecção (presença ou ausência de expressão). Após a detecção, os transcritos que estavam ausentes foram removidos. Para a análise estatística foi utilizado o teste RankProd, que é biologicamente projetado para testar e detectar genes diferencialmente expressos em experimentos de microarranjos. Foi utilizado um valor de p ? 0,01 e pfp ? 0,05, a fim de considerar os transcritos diferencialmente expressos. No geral, nossos resultados mostram uma assinatura molecular similar nos dois modelos de ratos genéticos analisados. Houve uma sobreposição na lista de genes diferencialmente expressos encontrados em ambos os modelos, quando comparado com controles. Além disso, descobrimos que duas importantes vias moleculares para epileptogênese: neurotransmissão GABAérgica e potencialização de longo prazo pós-sináptica NMDA-dependente, foram encontrados em ambos os modelos, quando combinamos os dados dos animais WAR e GEAS. No entanto, algumas diferenças nas vias de sinalização expressas nos dois modelos também foram identificadas. Portando os resultados mostram claramente a natureza heterogênea e complexa dos mecanismos moleculares envolvidos na epileptogênese / Abstract: Wistar audiogenic rat (WAR) is a genetic epilepsy model susceptible to audiogenic seizures, after high-intensity sound stimulation. Another genetic model we have recently identified is the generalized epilepsy with absence seizures (GEAS) rat. The aim of the present study was to characterize and compare the genetic profile of these two strains using gene expression analysis. Experiments were performed initially using microarray technology followed by quantitative real-time PCR. Results were analyzed in R environment using the Affy and RankProd packages from Bioconductor, using the algorithm MAS 5 we normalized the arrays and calculated the signal intensity and the detection (presence or absence of expression), after the detection, transcripts which were absent in all samples were removed. For statistical analysis we used the Rank Product test, which is biologically motivated and designed to test and detect differentially expressed genes in replicated microarray experiments. This is a simple non-parametric statistical method based on ranks of fold changes. We used a p-value ? 0.01 and a pfp ? 0.05 in order to consider a given transcript to be differentially expressed Overall, the results show a different molecular signature in the two genetic rat models analyzed, since different enriched gene ontology categories were found. However, there was some overlap in the list of genes differentially expressed found in both models when comparing to controls. In addition, we found that two important molecular pathways for epileptogenesis: GABAergic neurotransmission and: Neurophysiological process NMDA-dependent postsynaptic long-term potentiation in CA1 hippocampal neurons, were found to be present in both models when combining data from WAR and GEAS animals. In conclusion, our results clearly show the heterogeneous and intricate nature of the molecular mechanisms involved in epileptogenesis as well as the importance of studies looking at different regulatory pathways at once, in order to better appreciate this complexity / Mestrado / Neurociencias / Mestre em Ciências

Orientadores: Marilisa Mantovani Guerreiro, Catarina Abrão Guimarães / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-19T22:11:29Z (GMT). No. of bitstreams: 1 Neri_MarinaLiberalesso_D.pdf: 1266603 bytes, checksum: 21ed75ba94dfafe79f7d15127e020891 (MD5) Previous issue date: 2012 / Resumo: A epilepsia benigna da infância com pontas centrotemporais (EBIPCT) ou rolândica (ER) é a forma mais freqüente de epilepsia na infância e é classificada como sendo focal, genética e de evolução benigna. Apesar de não haver déficit intelectual, essas crianças podem apresentar alterações cognitivas específicas. O presente estudo teve como objetivos: identificar e descrever alterações de funções executivas em crianças com ER e verificar a influência de variáveis clínicas da epilepsia nas funções executivas. Os participantes foram submetidos à aplicação de testes de funções executivas. Foram incluídas crianças com diagnóstico clínico e eletroencefalográfico de ER. A maioria dos pacientes estava controlada e muitos deles encontravam-se sem medicação. Os resultados obtidos foram comparados com os de um grupo de crianças de um grupo-controle (GC) constituído de indivíduos normais, com idade e nível sócio-educacional semelhantes ao das crianças com epilepsia. Os dados coletados nos dois grupos foram analisados e comparados através dos testes estatísticos: Mann-Whitney, teste Qui-quadrado e teste Exato de Fisher. Os resultados mostraram que quanto aos dados numéricos crianças com ER obtiveram pior desempenho em cinco das seis categorias consideradas do Wisconsin Card Sorting Test (WCST): nº de erros, nº de erros perseverativos, nº de respostas perseverativas, nº de categorias completadas e nº de fracassos em manter o set. Considerando-se resultados categóricos crianças com ER obtiveram pior desempenho no Trail Making Test (TMT) parte B, no Teste de fluência verbal FAS e em três categorias do WCST: nº de erros, nº de erros perseverativos e nº de respostas perseverativas. Em relação à variável idade de início da epilepsia, crianças com início mais precoce apresentaram pior desempenho em um dos instrumentos utilizados quando comparadas com crianças com início mais tardio da epilepsia; em relação às demais variáveis da epilepsia, não foi possível qualquer tipo de análise; quanto às variáveis das crises, não houve diferença nos resultados obtidos pelos pacientes divididos em grupos. Diante desses resultados concluímos que: as crianças com ER apresentaram déficit em funções executivas quando comparadas com o grupo-controle; a bateria utilizada mostrou-se adequada para detecção das disfunções apresentadas pelas crianças com ER; em relação à variável da epilepsia idade de início, crianças com início mais precoce apresentaram pior desempenho do que crianças com início mais tardio da epilepsia; em relação às demais variáveis da epilepsia e às variáveis das crises, não houve diferença entre os dois grupos. Assim, nosso estudo segue a linha de raciocínio de que o termo benigno deve ser usado com cautela uma vez que nossos pacientes apresentaram déficits neuropsicológicos em funções executivas, independentemente da fase ativa da epilepsia e do uso de medicações / Abstract: The benign childhood epilepsy with centrotemporal spikes (EBIPCT) or rolandic epilepsy (RE) is the most common type of childhood epilepsy and is considered to be a focal, genetic and benign epilepsy. Although there is no intellectual deficit, these children may have specific cognitive impairments. This study aimed: to identify and describe changes in executive functions in children with RE and to verify the influence of clinical variables of epilepsy in executive functions. Participants were evaluated with tests to assess executive functions. We included children with clinical and EEG features of RE. Most patients were controlled and several were without medication. The results were compared with those of a control group (CG) comprised of normal subjects with age and socioeconomic level similar to that of the RE group. The data collected from both groups were analyzed and compared using statistical tests: Mann-Whitney, Chi-square and Fisher exact tests. The results showed that concerning the numerical data, children with RE had the worst performance in five of the six categories of the WCST: number of errors, number of perseverative errors, number of perseverative answers, number of completed categories and number of failures to maintain the set. Considering categorical results, children with RE had worse performance in Trail Making Test part B, Verbal fluency test FAS and three categories of the WCST: number of errors, number of perseverative errors and number of perseverative answers. Concerning the variable age of onset of epilepsy, children with earlier onset of epilepsy had a worse performance in one of the tools when compared with children with later onset of epilepsy; the other variables of epilepsy did not allow any analysis; considering seizure variables, there was no difference between the two groups. We conclude that: children with RE showed deficits in executive functions when compared with the control group; the set of tests was adequate to detect the dysfunctions presented by children with RE; in relation to the variable age of onset of epilepsy, children with earlier onset had a worse performance than children with later onset of epilepsy; concerning other epilepsy and seizure variables, there was no difference between the two groups. Thus, our study is in keeping with the idea that the term benign should be cautiously used since our patients had neuropsychological deficits in executive functions regardless of the active phase of epilepsy and the use of medications / Doutorado / Ciencias Biomedicas / Doutor em Ciências Médicas

Ph.D. / Epilepsy is a multidimensional disorder that extends beyond the medical implications to impact nearly every aspect of the person's life, as well as the lives of the people in the surrounding environment. Intractable epilepsy has a poor prognosis with possible worsening of seizures and cognitive decline over time. Anterior temporal lobe surgery for epilepsy provides an opportunity for the alleviation of seizures; however there are potential risks, to memory in particular. Research on surgery outcome thus far has evaluated outcome from a linear paradigm and has studied impact of surgery on isolated areas of function, the results derived from this have been largely inconsistent. So far, there has been very little research that focuses on the person as a whole, and as yet there has been no integrated approach to studying surgical outcome. The aim of the current study was therefore to investigate the impact of anterior temporal lobe surgery, specifically the symptomatic and functional surgical outcomes, in an integrated and holistic manner. This was done in accordance with the paradigm of complex systems theory as a critique of the previous literature in this field, and to gain a more holistic understanding of surgical outcome. A combination of methodologies was employed in order to achieve this. The sample consisted of male (n=10) and female (n=24) patients with intractable epilepsy undergoing left-sided (n=13) and right-sided (n=21) temporal lobe surgery at the Milpark Hospital Johannesburg between the ages of 14 and 58 (mean = 39 years), over a period of seven years. A pretest-posttest design was employed to obtain quantitative data (n=34). Post surgical assessments were conducted up to seven years post surgery (mean=3.6 years). Pre and post surgery assessment included neurocognitive functioning, particularly memory and language functions, by means of the Rey Complex Figure Test, Wechsler Memory Scale-Ill, and Controlled Oral Word Association Test; as well as emotional functioning, particularly depression and anxiety, by means of the Beck Depression lnventory-11 and Beck Anxiety lnventory-11. The quantitative data was subjected to statistical analysis of the sample as a whole, as well as gender and side of surgery comparisons, and included tests of normality of distribution of the data; the paired samples t-test; the independent samples t-test; the Wilcoxon Signed Ranks test; the Mann-Whitney U test; and the Wilks' Lambda test. A semi-structured interview was also conducted (n=30) in order to obtain qualitative data on the functional (psychosocial) aspects of outcome. The interview included an assessment of postoperative seizure outcome; changes in daily activity functions; the client's report on positive and negative outcomes of surgery; quality of life changes and satisfaction with surgery. The qualitative data was analysed using the methods of open coding and axial coding. The results for neuropsychological function reflected known lateralization effects with memory showing auditory-verbal memory deficits after left-sided surgery; and visual (figural) memory deficits after right-sided surgery. Gender differences reflected known neuropsychological differences with female superiority in verbal fluency and a male advantage on visual-spatial tasks. Importantly, there was no relationship between neuropsychological deficit and decrements in daily activity functions, emotional functioning or quality of life. This indicates little impact of neuropsychological deficit post surgery and may be an indication of the effectiveness of the preoperative screening procedures. The results for emotional functioning showed a statistically significant improvement in the 'moderate/severe' depression and anxiety groups from pre to post surgery. This indicates a substantial improvement in both depression and anxiety for this severity group. The qualitative results showed that surgery rendered 74% of the sample seizure free, 15% showing worthwhile improvement, and 11% no change or worse seizures. Seizure outcome however did not determine quality of life changes, even those with some improvement or no change still reported an improvement in quality of life post surgically. The functional outcomes showed little postoperative change in daily activity functions (driving, occupational functioning and marital status) but still a reported improvement in quality of life. There were far more reports on perceived positive than negative outcomes. The most positive benefit of surgery, as reported by participants, was that of increased feelings of control, decreased helplessness, and less anxiety and worry of having seizures. The overwhelming majority of participants reported improved quality of life (90%) and satisfaction with surgery (93%).

The mechanisms underlying the generation and spread of seizure activity have remained elusive despite a considerable research effort over the last two decades. Most of this work has concentrated on the characteristics of neuronal excitability and burst discharge at the single cell level. These studies have provided some understanding of the possible abnormalities of neurons within an epileptic focus, but little direct insight into the factors responsible for the striking synchronization of action potentials during interictal discharge or in the spread of synchronous activity across apparently normal brain tissue. Although synaptic activation probably plays a role in the generation of seizure activity, recent evidence indicates that seizure-like discharge can occur during chemical blockade of synaptic transmission (Jefferys and Haas 1982; Taylor and Dudek 1982). This rather surprising result emphasizes the importance of considering non-synaptic mechanisms for both the synchronization and spread of abnormal neuronal activity in the central nervous system. One important non-synaptic mechanism to consider is ephaptic interactions. This term refers to the direct electrical influence of extracellular field potentials on neuronal excitability. It is possible that ephaptic interactions, generated during seizure activity, simultaneously depolarize an entire population of neurons leading to both recruitment and synchronization of action potential discharge. This thesis investigates ephaptic interactions during evoked potentials in the hippocampal formation. The hippocampus is one of the most seizure-prone regions of the brain and its anatomical structure is ideal for the generation of field effects. Evoked potentials were used as "models" of synchronous neuronal discharge since they are more reproducible, easier to control, and better understood than seizure activity. This initial investigation of ephaptic interactions lays the foundation for further studies involving the complexities of epileptic activity. The first phase of this project examined the spatial characteristics of field potentials evoked in the hippocampus and the dentate gyrus. Current source density (CSD) analysis and voltage gradient determinations obtained from these fields were used to characterize the pattern of current flow within the neuropil and to predict the polarity and relative intensity of ephaptic influences on neuronal excitability. The detailed characteristics of extracellular voltage gradients varied between CAl and the dentate gyrus, and also between anti- and orthodromic responses. In general, voltage gradients during the positive components of a somatic population spike predicted ephaptic hyperpolarization of the neuronal population, whereas gradients observed during the negative component predicted depolarization. They were often an order of magnitude greater than the smallest gradient known to influence granule cell activity. An exception to this rule was the minimal gradient observed during the negative component of the dentate response. In the second phase of the study, extracellular voltage gradients were experimentally applied to the dentate gyrus to determine the sensitivity of granule cells to ephaptic interactions. The magnitude of the applied gradients were in the range observed during the evoked potentials studied in the first phase. These experiments demonstrated a remarkable sensitivity of granule cells to the applied fields. The fields could alter the population spike from near minimal to near maximal. Surprisingly, even antidromic potentials were influenced by the gradients. On the other hand, the EPSP phase of the population spike was not influenced. These findings established that extracellular currents can influence the excitability within a neuronal population without altering synaptic drive. The final phase of the project investigated the transmembrane potential (TMP) of pyramidal and granule cells during applied fields and evoked potentials. The TMP was calculated by subtracting the extracellular from the intracellular response. This potential ultimately determines the voltage dependent behavior of a neuron and gives a direct measure of any ephaptic interactions. In order to measure the intracellular influences of applied fields, the TMP was monitored while the impaled cell was exposed to extracellular voltage gradients spanning the same range as used in phase two of the project. The TMP shifted by as much as plus or minus 5 mV, depending on the amplitude and polarity of the gradient. This large shift in TMP accounts for the observed influence of the applied field potentials, and suggests that the voltage gradients associated with evoked potentials should also have a marked effect on the TMP. A depolarizing wave of the TMP occurred during the negative component of anti- and orthodromic CA1 responses. This depolarization was capable of initiating action potentials, and decreased the latency to discharge during orthodromic responses. During epileptiform discharge, a similar depolarizing wave was associated with each negative component of the burst. These depolarizations recruit and synchronize neuronal discharge by simultaneously increasing the excitability within an entire population of cells. These data support the hypothesis that ephaptic interactions in the hippocampal formation influence the pattern of cell discharge during evoked potentials. It is postulated that similar ephaptic interactions may contribute to recruitment and synchronization during seizure activity. / Medicine, Faculty of / Cellular and Physiological Sciences, Department of / Graduate

Orientador: Fernando Cendes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T20:41:16Z (GMT). No. of bitstreams: 1 Barbosa_PatriciaHorn_D.pdf: 4694168 bytes, checksum: 4b2bdfa4847274a2d3a88005c77669d2 (MD5) Previous issue date: 2015 / Resumo: Epilepsia de lobo temporal resulta com freqüência em refratariedade ao tratamento medicamentoso. Alguns fatores prognósticos da epilepsia focal e seu tratamento já foram descritos, mas outros ainda estão por ser melhor conhecidos. Nosso objetivo foi investigar associação entre alterações no EEG pré e pós-operatório e na ressonância de crânio pré-operatória com o resultado cirúrgico de pacientes com epilepsia de lobo temporal. Pacientes com epilepsia focal refratária submetidos a cirurgia após investigação não invasiva foram reavaliados. Calculamos o período livre de crises até a recorrência. Realizamos análise visual da RM crânio pré-operatória buscando sinais de atrofia hipocampal e alterações sutis no hipocampo contralateral. Revisamos exames de EEG pré e pós-operatórios buscando inicialmente a presença ou ausência de descargas epileptiformes. Posteriormente, quantificamos atividade epileptiforme interictal e buscamos associação com recorrência de crises. Utilizamos os testes estatísticos qui-quadrado e Fisher, quando adequados, e construímos curvas de sobrevivência de Kaplan-Meier, considerando recorrência de crises como desfecho, com comparação pelo método de Mantel. Na primeira parte do estudo foram incluídos 86 pacientes com atrofia hipocampal. EEG pré-operatório unilateral não se associou a resultado cirúrgico favorável; EEG pós-operatório com presença de atividade epileptiforme interictal não se associou a resultado cirúrgico desfavorável; RM cranio com hipocampo contralateral alterado se associou tanto a resultado cirúrgico desfavorável, quanto com bilateralidade nos EEGs pré-operatórios. Na segunda parte do estudo, com 129 pacientes incluídos, não encontramos associação significativa entre presença de atividade epileptiforme interictal no EEG pós-operatório e resultado cirúrgico. As curvas de sobrevivência dos grupos com descargas epileptiformes presentes versus ausentes não foram estatisticamente diferentes (p=0,09), porem observamos uma tendência, o que motivou a terceira parte. Desta forma, demonstramos, através da quantificação da atividade epileptiforme, associação entre descargas pouco frequentes no EEG pós-operatório com resultado cirúrgico favorável. Finalmente, na tentativa de estabelecer o EEG pós-operatório como preditor de recorrência de crises, não encontramos, com a amostra disponível, associação entre EEG pós-operatório com atividade epileptiforme pouco frequente e resultado cirúrgico favorável. Estes resultados demonstram que é importante valorizar alterações sutis no volume, conformação, eixo e sinal do hipocampo menos afetado na indicação de cirurgia de pacientes com epilepsia de lobo temporal e atrofia hipocampal. O resultado cirúrgico dos pacientes com hipocampo contralateral normal é mais favorável. Alteração eletrográfica bitemporal no EEG pré-operatório, em geral, está associada a alteração estrutural sutil no hipocampo contralateral, que muitas vezes não é valorizada. Tal achado corrobora evidências previamente descritas de que pacientes com EEG pré-operatório bitemporal tem prognóstico cirúrgico menos favorável. Os dados relacionados à análise quantitativa de descargas epileptiformes no EEG pós-operatório mostraram associação entre atividade epileptiforme e resultado cirúrgico. Tal achado sugere que o EEG pode ser uma ferramenta útil no seguimento clínico pós-operatório. Em conclusão, nossos resultados indicaram dois fatores importantes no prognóstico de controle de crises após cirurgia em ELT: presença de alteração hipocampal contralateral mesmo que sutil, e espículas em uma frequência maior que 4 por um período de 15 minutos / Abstract: Temporal lobe epilepsy is frequently linked to medical refractoriness. Many clinical prognostic data on focal epilepsy have repeatedly been described, while surgical outcome factors are yet to be fully known. We presently look into an association between interictal epileptiform discharges in pre and postoperative EEG, as well as preoperative brain magnetic resonance imaging, and surgical outcome of temporal lobe epilepsy. Patients with medically refractory focal epilepsy submitted to surgery following non invasive investigation were reassessed. We calculated time until seizure recurrence. We visually analysed preoperative MRI searching for signs of hipoccampal atrophy, as well as subtle contralateral hipoccampal changes. We reviewed pre and postoperative EEGs concerning presence or absence of interictal epileptiform discharges. Later on, we quantified interictal discharges and tested association with seizure freedom. We used chi square or Fisher¿s exact test, when most adequate. We also built Kaplan-Meier¿s survival curves setting seizure recurrence as endpoint, and compared curves by Mantel method. We initially included 86 patients with hipoccampal atrophy. Preoperative unilateral EEG was not associated with favorable surgical outcome; presence of IED in postoperative EEG was not associated with unfavorable outcome; contralateral hipoccampal changes on preoperative MRI was strongly associated with unfavorable surgical outcome, as well as with bilateral preoperative EEGs. We then studied postoperative EEGs of 129 individuals. There was not a significant association between postoperative EEG and surgical outcome. Survival curves of group of patients with interictal discharges present and absent were not statistically different (p=0.09), but we observed a tendency in that direction. Therefore, we were able to demonstrate through manual quantification of epileptiform discharges that postoperative EEG direct association with surgical outcome. Our ultimate goal was to establish postoperative EEG as predictor of seizure recurrence. Unfortunately we were not able to demonstrate it with data available on our sample. These results highlight importance of assessing subtle changes in volume, form, axis and signal intensity on contralateral hipoccampus prior to indication of surgery in patients with temporal lobe epilepsy with hipoccampal atrophy. Surgical outcome is more favorable when contralateral hipoccampus is normal. Bilateral discharges over temporal electrodes in pre-operative EEG are associated with subtle structural changes on contralateral hipoccampus, which may be underestimated. Such findings is in agreement with previously described evidence of bitemporal preoperative EEG associated with less favorable surgical outcome. Quantification data on postoperative EEG sets forth direct association with epileptiform discharges and surgical outcome. Such finding suggests EEG may be a useful tool in postoperative followup. In conclusion, our results indicate two important prognostic factors for seizure control in surgically treated temporal lobe epilepsy patients: presence of contralateral signs of hipoccampal sclerosis, even if subtle, and interictal epileptiform discharges occuring in a frequency higher than 4 at 15 minutes period / Doutorado / Neurociencias / Fisiopatologia Médica

Orientadores: IÍscia Teresinha Lopes Cendes, Cláudia Vianna Maurer-Morelli / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-27T14:57:39Z (GMT). No. of bitstreams: 1 Santos_RenatoOliveirados_D.pdf: 1790615 bytes, checksum: 5e996ae5810a67103c553e7bdc08ecc8 (MD5) Previous issue date: 2015 / Resumo: As epilepsias formam um grupo de doenças neurológicas crônicas caracterizadas por crises epilépticas, as quais podem ser definidas como um distúrbio intermitente do sistema nervoso causado por descarga elétrica anormal, súbita e sincronizada dos neurônios cerebrais. A epilepsia de lobo temporal (ELT) é a mais frequente, representando aproximadamente 50% dos casos em adultos e tem como manifestação típica, a crise parcial complexa. Além disso, é frequentemente refratária ao tratamento medicamentoso. Os principais sintomas gerados pela ELT são predominantemente pelo acometimento das estruturas mediais do lobo temporal, sendo a ELT mesial (ELTM), a forma mais comum de ELT. Atualmente é ainda controversa a participação de fatores genéticos contribuindo na etiologia das epilepsias, principalmente da ELTM, que não teve até hoje nenhum gene inequivocamente associado a sua predisposição. O objetivo deste trabalho foi investigar o papel de dois genes candidatos: o PTPRM e o IL1B na predisposição à ELTM. Para tanto utilizamos as seguintes modalidades de estudo em pacientes com ELTM (i) estudo de associação genética através da genotipagem de polimorfismos de nucleotídeo único (SNPs) localizados nos referidos genes candidatos (esta etapa do estudo foi realizada durante o mestrado); (ii) quantificação dos transcritos de ambos os genes, por PCR em tempo real em tecido das estruturas mediais do lobo temporal (principalmente hipocampo) que foi obtido através da realização de cirurgia para tratamento das crises refratárias. (iii) Para o PTPRM, foi também realizada a localização do transcrito pela técnica de hibridação "in situ" em tecido hipocampal de pacientes e de controle. Além disso, como existem evidências do envolvimento do PTPRM em etapas importantes do desenvolvimento cerebral, e pouco se conhece da função específica desse gene no cérebro realizamos (iv) a quantificação do transcrito de PTPRM durante o desenvolvimento em cérebro de camundongos. (v) Finalmente, com o objetivo específico de avaliar se o aumento de expressão de IL1B no tecido hipocampal se refletia também na circulação realizamos a quantificação do transcrito e proteica do IL1B no plasma de pacientes com ELTM. Nossos resultados revelaram associação genética entre SNPs localizados em ambos os genes investigados e o fenótipo estudado. No entanto, em nenhum dos estudos uma variante funcional pode ser identificada. A quantificação dos transcritos em tecido hipocampal dos pacientes com ELTM indicou que ambos os genes PTPRM e IL1B estão hiper-regulados em pacientes quando comparados ao tecido controle. Não identificamos variação significativa na expressão do transcrito de PTPRM no cérebro de camundongos nas diferentes etapas de desenvolvimento. Não identificamos variação significativa na quantificação do transcrito e proteica de IL1B no plasma dos pacientes com ELTM quando comparados aos controles. Em conclusão, nossos resultados dos estudos de associação indicam um papel de PTPRM e de IL1B na predisposição à ELTM, porém não fomos capazes de encontrar uma variante funcional associada ao fenótipo. Corroborando o papel de ambos os genes nosso estudo de expressão gênica no tecido acometido indicou um aumento de expressão de ambos os genes. No entanto, o aumento de expressão de IL-1beta no tecido hipocampal não se traduziu pelo aumento no plasma dos pacientes. Finalmente, nosso estudo do perfil de expressão de PTPRM durante o desenvolvimento cerebral não aponta para um papel desse gene em etapas específicas do desenvolvimento / Abstract: The epilepsies are a group of chronic neurological disorders characterized by seizures, which can be defined as an intermittent disorder caused by an abnormal and sudden electrical discharge of neurons in the brain. Temporal lobe epilepsy (TLE) is the most frequent form, representing approximately 50% of cases in adults, and it is often refractory to drug treatment. The main symptoms in TLE are generated by the involvement of the medial temporal lobe structures, characterizing mesial TLE (MTLE). The contribution of genetic factor to MTLE it is still controversial and to date, no gene has been unequivocally associated with the predisposition to MTLE. Therefore, the aim of this study was to investigate the role of two candidate genes: PTPRM and IL1B in the predisposition to MTLE. To achieve this we use the following type study modalities in patients with MTLE (i) genetic association study by genotyping of single nucleotide polymorphisms (SNPs) located in these two candidate genes; (ii) quantification of the transcripts of both genes by real-time PCR in hippocampal tissue obtained from epilepsy surgery for the treatment of refractory seizures. (iii) For PTPRM we also performed in situ hybridization experiments in order to localize the transcript in hippocampal tissue from patients and controls. Furthermore, since there is evidence that PTPRM could be involved in key stages of brain development and little is known about the specific role of this gene in the brain, we performed (iv) quantification of its transcript during development in mouse brain. (v) Finally, with the specific objective of assessing whether the increase of IL1B expression in hippocampal tissue was also seen outside the central nervous system we quantified IL1B transcript and protein in plasma of patients with MTLE. Our results revealed genetic association between SNPs located in both genes and the phenotype. The quantification of transcripts in hippocampal tissue of patients with MTLE indicated that both genes are hyper-regulated when compared to control tissue. We did not find any significant variation in transcript expression of PTPRM in mouse brain during developed. In addition, no difference in transcript expression and protein levels of IL1B was observed in plasma of patients with MTLE. In conclusion, our results indicate an involvement of PTPRM and IL1B in the predisposition to MTLE; however, we are unable to find a functional variant associated with the phenotype. Corroborating the role of both genes in MTLE gene expression in affected tissue (hippocampus) indicated an up-regulation of both genes. However, the increase in IL1B expression in hippocampal tissue was not reflected by an increase of transcript or protein in plasma of patients with MTLE. Finally, our expression profile of PTPRM during brain development does not point to a role for this gene in specific stages of development / Doutorado / Fisiopatologia Médica / Doutora em Ciências

The human neocortex is a highly sophisticated and organized brain structure that is thought to mediate some of the most complex cognitive functions in humans including language and abstract thought. As such, environmental and genetic insults to its normal structure or function can result in devastating neurological conditions including severe epilepsy and intellectual disability. Malformations of cortical development are an increasing collection of disorders that cause neocortical abnormalities due to impaired developmental processes. One recently identified disorder in this class is a thin lissencephaly variant (TLIS) associated with several mutations in the C-terminus death domain of the caspase-2 activation adaptor CRADD (also known as RAIDD). Beyond this, little is known about the mechanism underlying TLIS pathophysiology despite an increasing number of identified individuals suffering from it. In order to better understand this disorder, as well as the normal developmental mechanisms that are impaired in its pathogenesis, I have developed and characterized three murine models by introducing one of a number of different genetic perturbations associated with TLIS. These animal models show behavioral and biochemical abnormalities similar to those seen in human TLIS subjects. Focusing future studies on the developmental processes that underlie differences seen in these mouse models could greatly inform understanding of disease mechanism in humans and assist in the development in therapeutic interventions. My work presented in this dissertation thus effectively establishes a translationally relevant animal model of TLIS.