Pacientes com epilepsia farmacorresistente, frequentemente, possuem lesões extrahipocampais como etiologia. Muitas vezes, estes pacientes se beneficiam de lesionectomias para redução da ocorrência de crises epilépticas. Para que possam se submeter a este procedimento, atualmente é necessário o uso tanto da videoeletroencefalografia prolongada (VEEG) quanto da imagem de ressonância magnética do encéfalo (IRM) para delimitação apurada da zona epileptogênica, local que deve ser ressecado para controle das crises. No presente trabalho, foi estudada a acurácia diagnóstica da VEEG e da IRM na determinação da zona epileptogênica de pacientes com displasia cortical focal. Comparou-se os locais de ocorrência da zona de início ictal (VEEG) e da lesão epileptogênica (IRM) se concordantes ou discordantes com o local da cirurgia. Foram revisados os prontuários médicos de 209 pacientes, sendo o padrão de referência (local da cirurgia) e tempo de acompanhamento pós-operatório superior a 12 meses disponíveis em 43 pacientes. A VEEG apresentou sensibilidade de 85,7% (IC 95% 62,6-96,2) e especificidade de 41,1% (IC 95% 19,4-66,5), com valor preditivo positivo de 64,2% (IC 95% 44,1-80,6) e valor preditivo negativo de 70% (IC 95% 35,3-91,9). A IRM apresentou sensibilidade de 91,6% (IC 95% 71,5-98,5) e especificidade de 36,8% (IC 95% 17,2-61,3), com valor preditivo positivo de 64,7% (IC 95% 46,4-79,6) e valor preditivo negativo de 77,7% (IC 95% 40,1-96). As diferenças de sensibilidade e especificidade, áreas sob as curvas ROC e os índices de Youden não foram significativas. A concordância dos resultados da VEEG e da IRM foi moderada (k=0,599; p<0,01; IC 95% 0,468-0,730). / Patients with drug-resistant epilepsy frequently have extrahippocampal lesions as etiology. A large proportion of these patients might benefit from lesionectomy for the reduction of seizures. For surgery to be undertaken, it is usually performed both long-term videoelectroencephalography monitoring (VEEG) and magnetic resonance imaging of the brain (MRI) for the precise delimitation of the epileptogenic zone, the region that must be resected for seizure control. In the present study, the diagnostic accuracy of VEEG and MRI were studied in the localization of the epileptogenic zone in patients with focal cortical dysplasia. The seizure-onset zone (VEEG) and the region of epileptogenic lesion (MRI) were compared whereas concordant or discordant regarding surgery region. Medical charts of 209 patients were reviewed, being the reference standard (surgery region) and post-surgical follow-up longer than 12 months available in 43 patients. Videoelectroencephalography has a sensitivity of 85.7% (95% CI 62.6-96.2) and specificity of 41.1% (95% CI 19.4-66.5), with positive predictive value of 64.2% (95% CI 44.1-80.6) and negative predictive value of 70% (95% CI 35.3-91.9). Magnetic resonance imaging has a sensitivity of 91.6% (95% CI 71.5-98.5) and specificity of 36.8% (95% CI 17.2-61.3), with positive predictive value of 64.7% (95% CI 46.4-79.6) and negative predictive value of 77.7% (95% CI 40.1-96). The differences of sensitivity and specificity, areas under the ROC curves and Youden\'s indexes were not significant. The concordance between the results of VEEG and MRI was moderate (k=0.599; p<0.01; 95% CI 0.468-0.730).

A displasia cortical focal (DCF) é uma das causas mais frequentes de epilepsia refratária. Na clínica, diferentes informações são usadas para localizar o foco epileptogênico, mas nenhum método é autossuficiente para evidenciar o local original das crises, associado com a presença da DCF. Embora haja relatos na literatura indicando alterações no padrão de distribuição de tons de cinza e morfologia dos voxels decorrentes da DCF, algumas limitações dos métodos desenvolvidos ainda impedem a utilização clínica. Nossa proposta foi investigar a capacidade de identificar DCF através de análises de espessura cortical e padrões de textura em imagens estruturais de Ressonância Magnética (RM), validando os métodos desenvolvidos a partir uma base de imagens retrospectiva, cujo tecido epileptogênico já havia sido ressecado e a DCF confirmada em análise histológica. A caracterização das DCF foi feita a partir da segmentação automática de tecido cortical saudável em conjunto com a segmentação manual da DCF feita por um especialista, e consiste na geração de mapas de característica e extração de valores de distribuições para comparação em análise estatística. Investigamos também a eficácia da detecção de DCF através do uso de algoritmos de aprendizado de máquina para classificação automática. Obtivemos precisão 0,81 e sensitividade 0,87, colocando o método desenvolvido em par com outros métodos presentes na literatura. Entretanto, foi identificada uma grande dependência do desempenho de métodos de pré-processamento, como corregistro e segmentação automática. / Focal Cortical Dysplasia (FCD) is one of the most frequent causes of refractory epilepsy. In clinical procedures, the information gathered from different techniques is used in order to locate the epileptogenic focus, associated with the presence of FCD. However, there is no self sufficient method to evidence the presence and location of such lesions and especially its extension. Although there are reports indicating change in gray scale intensity patterns and voxel morphology in the presence of DCF, limitations in developed methods still prevent their clinical use. Our proposal was to investigate the capability of identifying FCD through cortical thickness and texture patter analysis in structural MRI images, validating developed methods by utilizing a retrospective base of images from patients that were subjected to surgery, with the FCD being confirmed in histological analysis. Characterization of FCD was achieved from automatic segmentation of healthy cortex and manual segmentation of FCD tissue made by an specialist, and consists in the generation of texture or structural feature maps and comparison of distribution values in healthy or FCD tissue with statistical analysis. We also investigate the efficiency of FCD detection with Machine Learning automatic classification, obtaining precision of 0,81 and sensitivity of 0,87, placing our method on par with other methods in the literature. However, there is a major performance dependency of proposed method with pre-processing steps, like registration and automatic segmentation.

A displasia cortical focal (DCF) é uma das causas mais frequentes de epilepsia refratária. Na clínica, diferentes informações são usadas para localizar o foco epileptogênico, mas nenhum método é autossuficiente para evidenciar o local original das crises, associado com a presença da DCF. Embora haja relatos na literatura indicando alterações no padrão de distribuição de tons de cinza e morfologia dos voxels decorrentes da DCF, algumas limitações dos métodos desenvolvidos ainda impedem a utilização clínica. Nossa proposta foi investigar a capacidade de identificar DCF através de análises de espessura cortical e padrões de textura em imagens estruturais de Ressonância Magnética (RM), validando os métodos desenvolvidos a partir uma base de imagens retrospectiva, cujo tecido epileptogênico já havia sido ressecado e a DCF confirmada em análise histológica. A caracterização das DCF foi feita a partir da segmentação automática de tecido cortical saudável em conjunto com a segmentação manual da DCF feita por um especialista, e consiste na geração de mapas de característica e extração de valores de distribuições para comparação em análise estatística. Investigamos também a eficácia da detecção de DCF através do uso de algoritmos de aprendizado de máquina para classificação automática. Obtivemos precisão 0,81 e sensitividade 0,87, colocando o método desenvolvido em par com outros métodos presentes na literatura. Entretanto, foi identificada uma grande dependência do desempenho de métodos de pré-processamento, como corregistro e segmentação automática. / Focal Cortical Dysplasia (FCD) is one of the most frequent causes of refractory epilepsy. In clinical procedures, the information gathered from different techniques is used in order to locate the epileptogenic focus, associated with the presence of FCD. However, there is no self sufficient method to evidence the presence and location of such lesions and especially its extension. Although there are reports indicating change in gray scale intensity patterns and voxel morphology in the presence of DCF, limitations in developed methods still prevent their clinical use. Our proposal was to investigate the capability of identifying FCD through cortical thickness and texture patter analysis in structural MRI images, validating developed methods by utilizing a retrospective base of images from patients that were subjected to surgery, with the FCD being confirmed in histological analysis. Characterization of FCD was achieved from automatic segmentation of healthy cortex and manual segmentation of FCD tissue made by an specialist, and consists in the generation of texture or structural feature maps and comparison of distribution values in healthy or FCD tissue with statistical analysis. We also investigate the efficiency of FCD detection with Machine Learning automatic classification, obtaining precision of 0,81 and sensitivity of 0,87, placing our method on par with other methods in the literature. However, there is a major performance dependency of proposed method with pre-processing steps, like registration and automatic segmentation.

Les dysplasies corticales focales de type 2 (DCF2) sont une cause fréquente d’épilepsie partielle pharmacorésistante pouvant bénéficier d’un traitement chirurgical. Leur détection en IRM est un facteur indépendant de bon pronostic. Leur diagnostic reste difficile avec jusqu’à 40% d’IRM négatives. Le travail de cette thèse a pour principal objectif d’améliorer la détection des DCF2 à partir des séquences conventionnelles, d’évaluer la pertinence d’une augmentation de champ magnétique, et de valider de nouveaux outils de détection, en particulier par l’identification d’anomalies des sillons associées aux DCF2 de manière automatique puis visuelles. Cette étude a été réalisée à partir d’une des plus importante cohorte de patients (>80 patients) porteurs de DCF2 prouvée histologiquement. L’évaluation de la fréquence de chacun des signes en IRM nous a permis de démontrer que, bien qu’aucune anomalie ne soit visible dans 41% des cas, les différents signes chez les patients avec une IRM positive n’étaient jamais isolés et que la combinaison des 3 signes les plus évocateurs de DCF2 (épaississement cortical, flou de l'interface blanc-gris et « transmantle sign »), était retrouvée chez 27 patients (64%) suggérant que l’IRM puisse être un examen très caractéristique. En augmentant le champ magnétique de 1,5 à 3T en IRM le taux de détection n’est que peu modifié mais la caractérisation des DCF2 est améliorée en raison d’une meilleure visualisation du « transmantle sign », considéré comme une signature en IRM des DCF2. L’analyse automatisée des sillons basés sur le calcul d’un nouveau paramètre appelé « énergie sulcale » permet d’identifier des motifs sulcaux anormaux chez les patients porteurs de DCF2 dans la région centrale en comparaison aux sujets sains. Ce résultat souligne l'importance d’une étude des sillons et pourrait fournir un critère supplémentaire pour détecter et localiser la lésion chez des patients à IRM négative. Enfin, l’analyse visuelle des sillons par un reformatage 3D du cortex nous a permis de décrire un nouveau marqueur des DCF2 de la région centrale : un motif sulcal dénommé le "Power Button Sign". Compte tenu de son excellente reproductibilité et de sa spécificité, il pourrait être utilisé comme un nouveau critère diagnostic majeur de DCF2 de la région centrale. L’ensemble de ces résultat participe à la meilleure compréhension des phénomènes développementaux impliqués dans la physiopathologie des DCF2 et offre de nombreuses perspectives pour l’amélioration de leur détection en imagerie. / Focal cortical dysplasia type 2 (FCD2) is a common cause of intractable partial epilepsy surgically treatable. Their detection by MRI is an independent factor of good prognosis. The MR imaging diagnosis remains difficult with up to 40% negative MRI. Our main objective is to improve the detection of FCD2from conventional sequences, to assess the relevance of increased magnetic field and validate new tools for detection, in particular by identifying sulcal abnormalities associated with FCD2 automatically and visually. This study was carried out from one of the largest cohort of patients (> 80 patients) with histologically proven FCD2. The evaluation of the frequency of each MR signs showed that, although no abnormality is seen in 41% of cases, the different signs in patients with a positive MRI were never isolated and the combination of the 3 most suggestive signs of FCD2 (cortical thickening, bluring of the gray-white matter interface and "transmantle sign") was found in 27 patients (64%), indicating that MRI can be very suggestive. By increasing the magnetic field from 1.5 to 3T MRI detection rate is only slightly changed but characterization of FCD2 is improved thanks to a better visualization of the " transmantle sign " considered as a MR signature of FCD2. The automated sulcus analysis based on the calculation of a new parameter called "sulcal energy" identifies abnormal sulcal patterns in patients with FCD2 in the central region in comparison to healthy subjects. This result underlines the importance of the identification of sulci and could provide an additional criterion for detecting and locating the lesion in patients with negative MRI. Finally, the visual analysis of sulci by 3D reformatting of the cortex allowed us to describe a new MR sign of FCD2 in the central region: a sulcal pattern called the "Power Button Sign". Given its excellent reproducibility and specificity, it could be used as a new major diagnostic criterion of FCD2 in the central region. All these results contribute to the better understanding of the developmental processes involved in the pathophysiology of FCD2 and offers many opportunities for improving their MR detection.

Optimizing of Epilepsy Surgery in Paediatric Patients Abstract Epilepsy surgery represents an effective treatment of intractable focal epilepsy. The presented work aims to describe the state of the art and enhance diagnostic and therapeutic algorithm in paediatric patients. The ultimate goal is to improve the outcome of surgeries. The work depicts the evolution of the paediatric epilepsy surgery program in Motol Epilepsy Center over the course of years 2000-2017. Complexity of patients (younger age, epileptogenic zone in proximity of eloquent cortex, multifocal MRI findings) and surgeries (hemispherotomy) alike increased over time. However, the outcomes in terms of postoperative seizure-freedom and complications remained stable. Cognitive abilities of patients improved by 9.1 IQ/DQ points one year after surgery. Patients with preexisting intellectual deficit reached the most significant increase. We developed a novel paradigm of intraoperative cortical electrical stimulation mapping. Furthermore, we introduced a technique employing visual detection of SEEG electrodes during the surgery. These procedures aim to achieve a complete resection while avoiding complications. We developed and standardized Czech versions of questionnaires IPES a QOLIE-AD-48 assessing quality of life in children with epilepsy. We...

Children with focal intractable epilepsy caused by MCD, FCD and TSC are in a high risk of development of cognitive delay, as a result of both drug resistant epilepsy and genetically determined abnormal structure of the neuronal networks. Epilepsy surgery represents an established and safe treatment method of focal drug resistant epilepsy, and increases the chances for these patients to be rid of epileptic seizures, anti-epileptic medication and cognitive comorbidities. Current data on genetic background of focal MCD and FCD and their comorbidities provide space to expand the diagnostic process in epilepsy surgery candidates. However, available information on genetic causes of MCD and FCD do not allow us to infer prognostic estimates on chances of seizure freedom and optimal cognitive development. Future studies should elucidate these uncertainties.

No description available.

No description available.

Les dysplasies corticales (FCD) sont une cause fréquente d’épilepsie lésionnelle requérant un traitement chirurgical, caractérisées par l’association de troubles de l’architecture corticale et la présence de cellules neuronales et/ou gliales anormales Les FCD restent parfois difficiles à identifier / localiser et la physiopathologie des activités épileptiques qu’elles produisent reste mal connue. L’objectif de ce travail est d’optimiser la localisation anatomique et fonctionnelle des FCD chez l’enfant et d’étudier leur épileptogénicité par une double approche, in vivo en imagerie de perfusion IRM-ASL (Arterial Spin Labeling), et in vitro par enregistrements de tissus humains post-opératoires sur matrice de micro électrodes. L’intérêt de l’étude de ces dysplasies chez l’enfant est majeure à un âge où la récurrence des crises n’a pas encore modifié le réseau … Tout d’abord, nous avons montré une hypoperfusion focale des dysplasies corticales focales de type II colocalisée à l’hypo métabolisme en 18FDG-PET scan et au défect histologique. Nous avons développé une méthode d’analyse statistique du signal ASL permettant l’intégration des données objectives de l’imagerie dans une approche multimodale des anomalies interictales associant ASL et IRM fonctionnelle-EEG. Ensuite, nous avons exploré in vitro des tranches de cortex humain dysplasique post-opératoire. La présence d’activités épileptiques interictales spontanées témoignait de la persistance des caractéristiques épileptogéniques des FCD, variables selon les sous types histologiques. L’étude de la signalisation GABAergique et de la régulation du chlore a montré que le co transporteur du chlore NKCC1 chargeait excessivement les neurones en chlore alors que son concurrent KCC2, extrudant normalement ces anions, était down-régulé. La dérégulation neuronale du chlore qui en résulte est à l’origine d’effets paradoxalement dépolarisants du GABA, rendant compte non pas d’une perte d’inhibition GABAergique mais de son implication active dans les processus épileptiques. Enfin, nous avons contribué à mettre en évidence le rôle des hémicanaux Pannexines1, et de la transmission purinergique dans l’initiation et la maintenance des activités ictales, ouvrant une nouvelle piste thérapeutique chez les patients présentant ces épilepsies pharmaco résistantes. / Focal cortical Dysplasias (FCD) are a frequent etiology of lesional epilepsy, requiring surgical treatment. They are defined by abnormalities of cortical architecture intermixed with the presence of abnormal neuronal or glial cells. Imaging FCD remains challenging, both to detect and map the lesion, and the pathophysiology of the epileptic discharges they produce is incompletely understood. The aim of this PhD is to improve in vivo FCD mapping in children with perfusion MRI, and to study in vitro their epileptogenicity with human postoperative cortical slices electrophysiological recordings on micro electrode arrays. First, we showed with ASL MRI (Arterial Spin Labeling) a focal hypoperfusion in type II FCD, colocalized with 18FDG-PET hypo metabolism and histological defects. We developed a statistical analysis of ASL under SPM integrated in a multimodal approach of FCD with EEG-fMRI and ASL-MRI. Second, we studied in vitro slices of human postoperative dysplastic cortex. We could record reliable spontaneous inter ictal discharges, specific of the histological subtype, showing that tissues retain epileptogenic features. We focused our study on GABAergic signaling and neuronal chloride regulation. We have identified an excessive chloride load in neurons by the co transporter NKCC1 whereas chloride extrusion was deficient because of KCC2 down regulation. The consequent chloride dysregulation resulted in paradoxical GABAergic depolarization, responsible for a loss of inhibitory processes but also a shift to excitatory effects of GABAergic signals. Third, we also contributed to a study on Pannexin hemichannels, revealing that Pannexin1 channels sustain initiation and maintenance of ictal activity though purinergic neurotransmission in human cortical slices, supporting new anti epileptic targets in human pharmaco resistant epilepsies.

p83 é uma proteína com massa molecular aparente de 83 kDa, supostamente ainda não descrita, específica de sistema nervoso, e desenvolvimento regulada. p83 interage fortemente com laminina, Tau, tubulina e heat shock protein 90. p83 foi inicialmente detectada por imunohistoquímica e western blot usando-se um anticorpo anti-lectina KM+ purificado por afinidade. Sua purificação a partir de cérebro de rato está em progresso. Identificar o envolvimento de p83 em processos do Sistema Nervoso Central humano é um passo necessário em direção à compreensão de sua função biológica. Uma biblioteca de expressão de cDNA de cerebelo de rato (Lambda ZAP II, Stratagene) foi submetida ao screening, usando-se um anticorpo específico para isolar o cDNA de p83. O anticorpo anti-KM+ foi pré-adsorvido contra proteínas de E. coli XL1 Blue MRF, antes de ser usado no screening. As membranas foram reveladas por imunodetecção cromogênica (fosfatase alcalina e NBT/BCIP). A análise de todos os clones Lambda ZAP II foi feita por excisão in vivo do fagomídeo pBluescript, subclonagem em E. coli XL1 Blue MRF, purificação do DNA plasmidial e digestão com Eco RI. A seqüência correspondente ao clone isolado foi analisada usando-se ferramentas e bancos de dados do NCBI. A seqüência nucleotídica mostrou identidade com as isoformas A e E de drebrina. As isoformas A e E de drebrina foram detectadas em adulto e embrião, respectivamente. Drebrina A é uma proteína sistema nervoso-específica, desenvolvimento regulada e associa-se com F-actina. Embora drebrina e p83 compartilhem propriedades em comum, nossos dados de western blot indicaram que parecem não se tratar da mesma proteína. Nós investigamos a expressão de drebrina em Displasia Cortical Focal tipo IIB, comparando com córtex normal. As secções de tecido foram coradas com hematoxilina-eosina e prata (Bielchowsky). Secções foram processadas por imunohistoquímica usando-se os anticorpos anti-drebrina M2F6 e o DAS2, e recuperação antigênica. A detecção foi feita usando-se um anticorpo biotinilado, e DAB como cromógeno. Os tecidos displásicos (13 casos) foram obtidos cirurgicamente de tecidos exibindo epilepsia droga-resistente. Os controles foram obtidos de necrópsia de 15 pacientes sem história prévia de doenças neurológicas ou alterações patológicas. Nossos resultados sugerem uma associação entre drebrina e DCF IIB, um distúrbio do desenvolvimento cortical. / p83 is 83 kDa protein supposedly not yet described, nervous system specific, and developmentally regulated. p83 strongly interacts with laminin, Tau, tubulin and heat shock protein 90. It was initially detected by immunohistochemistry and western blot using an affinity-purified anti-lectin KM+ antibody. Its purification from rat brain is in progress. Identifying the involvement of p83 in human Central Nervous System processes is a required step towards understanding its biological roles. A premade cDNA rat cerebellum expression library (Lambda ZAP II, Stratagene) has been screened, using a specific antibody to isolate p83 cDNA. Anti-KM+ antibody was pre-adsorbed against E. coli XL1 Blue MRF proteins, before using in screening. Membranes were revealed by cromogenic immunodetection (alcaline fostase and NBT/BCIP). The analysis of all positive Lambda ZAP II clones was carried out by in vivo excision of pBluescript, subcloning in E. coli XL1 Blue MRF, plasmidial DNA purification and Eco RI digestion. The sequence corresponding to the clone isolated was analyzed using the NCBI tools and database. The nucleotide sequence showed identity with drebrin A and E isoforms. Drebrin A and E isoforms were detected in adults and embryos. Drebrin A is a neuron-specific, development-regulated F-actin-binding protein. It participates in growth cone extension and dendritic spine formation. Although have same drebrin and p83 properties in common, they not seem to be the same protein. We have investigated the expression of drebrin in Focal Cortical Dysplasia type IIB (FCD IIB) as compared to normal cortex. Tissue sections were stained with hematoxylin-eosin and silver (Bielchowsky). Sections were processed for immunohistochemistry using anti-drebrin antibodies M2F6 and DAS2, and an antigen retrieval technique. Detection was carried out using a biotinylated antibody, using DAB as chromogen. Dysplastic tissues (13 cases) were obtained at surgery for drug-resistant epilepsy. Controls were obtained at autopsy from 15 patients without history of neurological disorder and gross pathological changes. A specific drebrin labeling in dysplastic tissue was more intense than in controls. Indeed, most control cases exhibited at most a slightly higher staining than the background. Balloon, clear and undetermined cells, and giant, dysmorphic neurons, showed a conspicuous labeling by anti-drebrin. These cells showed a thin rim labeling of the nuclear membrane, and a finely punctate nuclear labeling. In contrast, a coarse nuclear, but a faint cytoplasm labeling was observed in autopsy cases. Our data suggest an association between Drebrin expression and the FCD IIB, a disturbance of cortical development.