Licentiatavhandling (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 2 uppsatser.

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2008. / Härtill 4 uppsatser.

Zugl.: Habil'schrift Bern.

Thesis (M.S.) -- University of Texas Southwestern Medical Center at Dallas, 2006. / Not embargoed. Vita. Bibliography: 62-72.

Orientadores: Fernando Cendes, Íscia Lopes-Cendes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-18T00:02:21Z (GMT). No. of bitstreams: 1 Bilevicius_Elizabeth_D.pdf: 3815616 bytes, checksum: 984636c562a41b059889857b7a8b2037 (MD5) Previous issue date: 2011 / Resumo: O objetivo foi realizar uma análise multifatorial dos aspectos clínicos e de ressonância magnética (quantitativos e qualitativos) relacionados à resistência ao tratamento com drogas anti-epilépticas (DAES) em pacientes com epilepsia de lobo temporal mesial e melhor caracterizar o grupo de resposta intermediário a DAES, aqui denominado remitente-recorrente. Foram incluídos 165 pacientes e divididos em 3 grupos de acordo com a resposta medicamentosa: 50 respondedores (31 mulheres) , 87 não respondedores ao uso de DAES (53 mulheres) e 28 remitentes-recorrentes (17 mulheres) . Estes foram avaliados quanto à idade, freqüência de crises e idade no início destas, presença de crises febris, presença e lateralidade da atrofia hipocampal à análise visual, fatores precipitantes e DAES utilizadas. A quantificação dos volumes hipocampais foi realizada através de volumetria manual pelo software DISPLAY e as comparações dos volumes médios de ambos os hipocampos foi realizada entre os 3 grupos e 30 controles sadios por ANOVA. As imagens de ressonância magnética também foram avaliadas através da técnica de Morfometria Baseada em Voxel (VBM) com o software SPM 5 (Statistical Parametric Mapping)/MATLAB 7.7.0, comparando os três grupos com 75 indivíduos normais e entre si através de Teste -T. Observamos que idade de início das crises foi menor (p=0,005) e a freqüência das crises ao início foi maior (p=0,018) em farmacorresistentes quando comparado aos outros 2 grupos. As DAES mais utilizadas foram a carbamazepina e o clobazam (em associação) em todos os grupos. As doses de carbamazepina utilizadas foram maiores em farmacorresistentes (p<0,001) e remitentes-recorrentes (p=0,02) em comparação aos responsivos. Em relação ao clobazam, observamos dose significativamente maior somente nos farmacorresistentes em comparação aos outros dois grupos (p=0,017). A comparação da média dos volumes hipocampais entre os 3 grupos e controle evidenciou diferenças somente entre farmacorresistentes e controles bilateralmente (esquerda ,p = 0,004; direita, p=0,02). A análise por VBM evidenciou atrofia de substância cinzenta em todos os grupos. No grupo farmacorresponsivo tal atrofia foi mais restrita a áreas ipsilaterais ao foco epileptigênico, ao passo que nos grupos farmacorresistente e remitente-recorrente esta atrofia apresentou-se mais difusa. A comparação entre os grupos evidenciou as seguintes áreas com maior redução de substância cinzenta nos grupos farmacorresistente e remitenterecorrente quando comparados aos farmacorresponsivos: frontal periorbital bilateral (p<0,01), cíngulo (p<0,05) e temporal contralateral ao foco epileptogênico (p<0,05). Desta forma, observamos que embora as características clínicas demonstrassem mais similaridades entre os grupos respondedor e remitente-recorrente, a análise de VBM mostrou redução de substância cinzenta mais difusa em farmacorresistentes e remitentesrecorrentes. Assim pudemos observar que as variáveis clínicas relacionadas ao pior prognóstico foram idade e freqüência de início de crises. Em relação às variáveis estruturais, embora a atrofia de substância cinzenta (SC) se apresentasse mais difusamente em pacientes de pior resposta medicamentosa, também ocorre em áreas extra-hipocampais e mesmo extratemporais em pacientes considerados farmacorresponsivos mesmo que ipsilateralmente ao foco epileptogênico. Por último, conseguimos caracterizar clínica e estruturalmente o grupo remitente-recorrente, observado na prática clínica, porém até então muito pouco reconhecido na literatura / Abstract: The objective of the present work was to investigate the relationship between brain MRI and clinical characteristics and patterns of antiepileptic drug (AED) response in patients with mesial temporal lobe epilepsy (MTLE).In order to do that,one hundred sixty five MTLE patients were divided into seizure-free with AED (50 AEDresponders, 31 women), 87 pharmacoresistants (53 women), and 28 remitting-relapsing seizure control group (17 women). All groups were evaluated regarding age, frequency of seizures and age at epilepsy onset, duration of epilepsy, febrile seizures (FS), presence and side of hippocampal atrophy on visual inspection (HA), initial precipitating injuries (IPIs), type and quantity of AEDS used. The right and left hipoccampi from 99 patients belonging to all three groups (43 pharmacoresistants, 31 pharmacoresponsive and 25 remitting-relapsing subjects). were submitted to manual morphometry by DISPLAY software (Brain Imaging Centre, Montreal, Canada) as well as hipoccampi selected from 30 healthy controls. The calculated mean from those hipoccampi were compared within subjects and with controls. For gray matter (GM) MRI voxel-based morphometry (VBM) we selected only patients with unilateral HA on visual MRI analysis (n=100). Comparisons were made between all groups and 75 healthy controls. Age at epilepsy onset was lower (p=0,005) and initial frequency of seizures was higher in pharmacoresistants compared with the other two groups (p=0,018). The most used AEDS were carbamazepine and clobazam (always in association). The highest carbamazepine dose was observed in pharmacorresistants (p<0,001) and remitting-relapsing group (p=0,02). The highest dose of clobazam occurred only in pharmacoresistant group (p=0,017). The comparison between the mean hippocampi volumes from three groups and controls showed differences only on the pharmacoresistants left (p=0,004) and right(p=0,02) hippocampus comparing to controls. All groups showed GM atrophy compared to controls in ipsilateral hippocampus, bilateral parahippocampal gyri, frontal, occipital, parietal and cerebellar areas. In the AED-responders group such findings were more restricted to areas ipsilateral to the epileptic focus and more widespread in pharmacoresistants and remitting-relapsing groups. VBM pairwise comparisons showed areas with GM volume reduction in pharmacoresistants and remitting-relapsing compared with AED-responders in bilateral periorbital frontal (p< 0,01), cingulum (p<0,05), and temporal lobe contralateral to the epileptic focus (p< 0,05). We may conclude that, pharmacoresistants and remittingrelapsing patients presented a similar pattern of GM atrophy which was more widespread compared with AED-responders on VBM. We could also observe that age at epilepsy onset was lower (p=0,005) and initial seizure frequency was higher in pharmacoresistants / Doutorado / Neurociencias / Doutor em Ciências

Orientador: Fernando Cendes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-13T01:46:44Z (GMT). No. of bitstreams: 1 Campos_BrunoAugustoGoulart_M.pdf: 774663 bytes, checksum: ef708c3035e1e8aaca7bef6613de3b28 (MD5) Previous issue date: 2009 / Resumo: Objetivos: Comparar as medidas relativas de N-Acetil Aspartato (NAA) em pacientes com epilepsia do lobo temporal (ELT) entre aqueles com resposta adequada a primeira droga anti-epiléptica (DAE) com aqueles que não responderam a primeira DAE, requerendo outra monoterapia ou politerapia. Métodos: Nós estudamos 27 indivíduos no grupo-controle, 25 pacientes com ELT com resposta a primeira DAE (grupo-resposta) e 21 que não responderam a primeira DAE (grupo-falência) e que eram regularmente acompanhadas no nosso serviço de epilepsia. Todos foram submetidos a estudo por imagem e espectroscopia pela RNM e a razão NAA/Creatina foi calculada. Resultados: A razão NAA/Creatina foi testada por análise de variância (ANOVA) entre os grupos, mostrando uma significativa redução tanto no hipocampo ipsilateral quanto no contralateral relacionado ao EEG (p<0,001 e p=0,021 respectivamente). A análise post hoc não mostrou diferença significativa entre o grupo-resposta e o grupo-controle, mas com diferença entre o grupo-falência e os outros grupos. A análise individual mostrou uma redução maior que dois desvios-padrão abaixo da média dos controles em nove dos 21 (42,8%) pacientes no grupo-falência, mas em nenhum dos pacientes no grupo-resposta. Discussão: Nosso trabalho mostrou uma redução significativa na razão NAA/Cre no grupo com falência à primeira DAE, mas não no grupo com que apresentou resposta à primeira DAE comparado aos indivíduos do grupo controle. Estes resultados indicam que pacientes com ELT com resposta à primeira DAE têm menos evidência de dano ou disfunção neuronal/axonal comparado a aqueles refratários a primeira DAE. / Abstract: Purpose: To compare relative N-acetylaspartate (NAA) measurements in temporal lobe epilepsy (TLE) patients with good response to the first trial of AED (an important prognostic factor) to TLE patients who failed the first AED trial and required further AED trials with monotherapy or polytherapy. Methods: We studied 27 individuals in control-group, 25 TLE patients who responded to the first AED (response-group) and 21 who did not (failure-group) that were regularly seen at our Epilepsy Service. They were submitted to both MRI and proton spectroscopy, and NAA/Creatine ratio calculated. Results: ANOVA of NAA/Cre demonstrated significant reduction in both ipsilateral and contralateral hippocampus related to EEG focus (p<0.001 and p=0.021), and post hoc analysis of ipsilateral and contralateral hippocampus did not reach statistic significance between response-group and control-group, but we found difference between failuregroup and the others groups. Individual analysis showed NAA/Cre ratios lower than 2 SD below the mean of controls in nine of 21 (42.8%) patients in the first AED failure group (six with unilateral and three with bilateral NAA/Cre reduction) but in none of patients who responded to first AED. Discussion: Our study demonstrated observed in refractory and mild TLE patients with HA. These results indicates that patients with TLE who respond well to first AED have significantly less evidence of neuronal and axonal damage/dysfunction compared to those who are refractory to first AED. / Mestrado / Neurociencias / Mestre em Fisiopatologia Médica

Orientadores: Li Li Min, Fernando Cendes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-04T03:09:51Z (GMT). No. of bitstreams: 1 Bonilha_LeonardoFatorGouvea_D.pdf: 8420238 bytes, checksum: 016f0b30e07800517df57c5fc2672c09 (MD5) Previous issue date: 2004 / Resumo: A esclerose hipocampal (EH) é a alteração histológica mais comum em pacientes com epilepsia do lobo temporal medial (ELTM). A Ressonância Magnética (RM) de crânio possibilita a detecção in vivo de sinais associados à EH, permitindo que pacientes com EL TM reftatária à medicação sejam submetidos à ressecção cirúrgica do hipocampo para tratamento de crises epilépticas. As causas de reftatariedade à medicação e ao tratamento cirúrgico ainda são desconhecidas, porém supõe-se que um dos motivos seja a presença de lesão neuronal acometendo outras áreas cerebrais além do hipocampo. O uso da morfometria por RM permite avaliação do dano neuronal tanto no hipocampo como em outras estruturas cerebrais através da avaliação e quantificação da atrofia presente nestas estruturas. Para avaliação pormenorizada das estruturas cerebrais foi realizada a implementação e validação de um protocolo anatômico para mensuração da região mesial do lobo temporal, com uso de RM tridimensional de alta definição. Foi também definido um protocolo para volumetria automatizada baseada em voxel de todo o cérebro. Foi observado que o dano neuronal em pacientes com EL TM se estende além do hipocampo e acomete regiões que se conectam funcionalmente e anatomicamente ao hipocampo. Tál achado sugere que exista lesão abrangendo uma rede neuronal, o que pode ser responsável em conjunto pelas manifestações clínicas observadas nesses pacientes / Abstract: Hippocampal sclerosis (HS) is the most common histological finding in patients with media! temporal lobe epilepsy (MTLE). Magnetic resonance imaging (MRl) permits in vivo detection of signs that are associated to HS, permitting the surgical treatment for these patients. The causes of medical and surgical reftactoriness observed in patients with MTLE are still unknown. One possible explanation is the fact that the neuronalloss encountered in these patients spans over other brain areas beyond the hippocampus. The use of morphometric quantification of brain structures through MRI is a powerful tool to investigate the neuronalloss in the hippocampus and in other areas of the brain. In order to assess the neuronal damage in brain structures of patients with MTLE, we developed a protocol for manual MRI morphometry of the media! temporallobe structures. We also developed an automatic protocol to assess the concentration of gray matter in the whole brain of these patients through the use of Voxel Based Morphometry. We observed that patients with MTLE exhibit neuronal loss that is not restricted to the hippocampus, but affects di:fferent areas throughout the brain that are functionally and anatomica1ly connected to the hippocampus. These findings suggest that a lesion of a network of neural structures may be responsible for the clinical symptomatology exhibited by patients with MTLE / Doutorado / Neurologia / Doutor em Ciências Médicas

The perirhinal cortex (PER), which is critical for associative memory and stimulus discrimination, has been described as a wall of inhibition between the neocortex and hippocampus. With advanced age, rats show deficits on PER-dependent behavioral tasks and fewer PER principal neurons are activated by stimuli, but the role of PER interneurons in these altered circuit properties in old age has not been characterized. In the present study, PER neurons were recorded while rats traversed a circular track bidirectionally in which the track was either empty or contained eight novel objects evenly spaced around the track. Putative interneurons were discriminated from principal cells based on the autocorrelogram, waveform parameters, and firing rate. While object modulation of interneuron firing was observed in both young and aged rats, PER interneurons recorded from old animals had lower firing rates compared with those from young animals. This difference could not be accounted for by differences in running speed, as the firing rates of PER interneurons did not show significant velocity modulation. Finally, in the aged rats, relative to young rats, there was a significant reduction in detected excitatory and inhibitory monosynaptic connections. Together these data suggest that with advanced age there may be reduced afferent drive from excitatory cells onto interneurons that may compromise the wall of inhibition between the hippocampus and cortex. This circuit dysfunction could erode the function of temporal lobe networks and ultimately contribute to cognitive aging.

No description available.

The research of my thesis focused on the use of transcriptomic open discovery approaches to interrogate the molecular basis of two distinct yet related neurological disorders that are both associated with cognitive decline, Temporal Lobe Epilepsy and Alzheimer’s Disease. Interestingly, a potential role for compromised synaptogenesis early in disease was common to both, as was the direct role that neurons may play in brain inflammatory processes involving glia. Temporal lobe epilepsy (TLE) is a progressive disorder mediated by pathological changes in molecular cascades and hippocampal neural circuit remodeling that results in spontaneous seizures and cognitive dysfunction. Targeting these cascades may provide disease-modifying treatments for TLE patients. Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) inhibitors have emerged as potential disease-modifying therapies; however, a more detailed understanding of the contribution of JAK/STAT signaling to epileptogenesis is required to increase the potential therapeutic efficacy and reduce adverse effects associated with un-targeted JAK/STAT inhibition. With our collaborators, my lab developed a mouse line in which tamoxifen treatment conditionally abolishes STAT3 signaling from forebrain excitatory neurons (nSTAT3KO). Seizure frequency (continuous in vivo electroencephalography) and memory (contextual fear conditioning and motor learning) were analyzed in wildtype (Wt) and nSTAT3KO mice after intrahippocampal kainate (IHKA) injection as a model of TLE. Selective STAT3 KO in excitatory neurons reduced seizure progression and hippocampal memory deficits without reducing the extent of cell death or mossy fiber sprouting induced by IHKA injection. In my thesis, RNA was extracted from harvested hippocampi 24 h after IHKA and libraries were prepared for bulk RNA-sequencing (70–80 million reads/sample) using the NextSeq 500 Illumina system. 3190 genes were differentially expressed in Wt mice injected with KA vs saline (fold change |1.5|, FDR=<0.05). Ingenuity Pathway Analysis (IPA) revealed significant enrichment in 2 overarching sets of pathways: 1) those related to synaptic signaling and 2) those related to inflammation. As expected, many of the IHKA-induced genes were previously associated with epilepsy or seizure disorders (260 for Seizure Disorder, 267 for Epilepsy or Neurodevelopmental Disorder), and Seizure Disorder had the highest activation score in Neurological Disease based on gene expression patterns. Interestingly, a closer analysis of the IHKA-induced gene set revealed an enrichment of STAT3-associated genes (216), most of which were upregulated by IHKA. Compared to the 3190 Differentially Expressed Genes (DEGs) between IHKA and saline-injected Wt mice 24 hours after SE, more than half of these DEGs (1609) were rescued when comparing IHKA-injected nSTAT3KO mice and saline-injected Wt mice, indicating a significant rescue of gene expression when nSTAT3 is absent in excitatory neurons. While nSTAT3 KO influences the expression of genes in many different pathways, including the reversal of genes whose expression was inhibited in pathways of learning and memory by IHKA, the greatest surprise came from the predicted regulatory control over microglial function. nSTAT3KO mice displayed the greatest number of rescued DEGs compared to IHKA-injected WT mice in pathways that regulate inflammation and ion transport, and while inflammation was an expected response to IHKA, we were surprised to find evidence for its rescue in nSTAT3 KO mice. We also interrogated the expression of the Alzheimer’s disease genome as modeled using a rat model (TgF344-AD ) of familial AD that allows for behavioral and molecular characterization of AD, and expresses an endogenous pathogenic form of tau in addition to Abeta oligomers and plaques. AD is a neuropsychiatric disorder characterized initially by short term memory loss and disorientation, followed by declining cognitive functioning, and eventually, death. Widespread failure of 99% of AD drugs that make it to clinical trials has led to renewed interest in early signatures of disease in hopes of altering disease trajectory through early intervention. Key to such efforts is capturing a molecular window into AD at its earliest stages. The TgF344-AD rat shows overt pathology (including Aβ plaques, frank neuronal loss, and endogenous tau pathology) at 16 and 26 mo, but only to a very limited extent at 6 mo (Towne, 2013). Thus, in my thesis research, we set out to uncover any cell-type specific transcriptomic alterations that may be present in advance of major behavioral deficits or appearance of pathology, given that a strong body of literature suggests a long pre-symptomatic stage of illness in which subtle abnormalities may be present. 10x Genomics’ v3 gene expression assays were used to perform snRNA-seq on freshly dissected hippocampi from 6 mos, 9 mos and 19 mos littermate pairs of Tg and Wt rats (n=16 for 6 months and 9 months, with 8 for 19 months). ~2000 cells/subject were collected, and cDNA libraries were sequenced to a depth of ~120k reads/nuclei. Interestingly, data analysis revealed wide-scale gene changes in dentate granule cells (DGCs) and non-DGC excitatory neurons (Excit Ns) at 6 mos, suggestive of a significant decrease in synaptogenesis in Tg vs their Wt littermates, as well as small increases in cholesterol biosynthesis in the Tg rats in these cell types. By 9 months, some differentially expressed genes were observed across genotype in classes of glial cells, but the strongest impact on gene expression could still be seen in Excit Ns and DGCs, which continued to display evidence of decreased synaptogenesis, though to a lesser extent than at 6 mos. Interestingly, 9 mos Tg rats displayed an even stronger upregulation in genes related to cholesterol biosynthesis than 6 mos for both DGCs and Excit Ns. At 19 months, cholesterol and steroid biosynthesis were amongst the top biological pathways enriched for in Excit Ns and Inhibitory neurons of the Tg, to an even greater extent than changes in synaptogenesis. Altogether, our results suggest the transcriptional basis for a profound suppression of synapse formation or maintenance during early stages of illness in the TgF344-AD rat model, as well as abnormalities in neuronal cholesterol biosynthesis. Given that cholesterol is a key component of plasma membranes and lipid rafts, structures needed for the generation of new synapses and the stability of their receptor populations, it may be that deficiencies in the available cholesterol of Tg neuronal cells is leading to the impaired synaptogenesis in these cell types. Future work will focus on identifying whether these transcriptional alterations can be detected at even earlier time points, whether they are prescient for changes at the membrane in vivo that are correlated with memory impairment, and whether they are related to the alterations in the genome seen in our acquired epilepsy models, suggesting a common theme for the brain’s genomic response to injury of the hippocampus. / 2025-02-12T00:00:00Z