INTRODUÇÃO: Acidente vascular cerebral (AVC), depressão e prejuízo cognitivo são comorbidades associadas à alta carga mundial de incapacidade. Depressão e prejuízo cognitivo são condições que ocorrem mais frequentemente em pacientes pós-AVC e estão associadas a um aumento da morbimortalidade. OBJETIVO: Investigar potenciais fatores de risco cerebrovasculares associados ao desenvolvimento de depressão pós-AVC (DPA) e prejuízo cognitivo pós-AVC (PC) com base na neuroimagem por ressonância magnética cerebral (RM) e biomarcadores (serotonina, BDNF, IL-6, IL-18) na fase subaguda (1-3 meses) e na fase crônica (até 2 anos de seguimento) após o AVC em sobreviventes do Estudo de Mortalidade e Morbidade do AVC (EMMA), São Paulo, Brasil. MÉTODOS: Amostra de participantes admitidos por AVC no Departamento de Emergências do HU-USP, de abril de 2006 a novembro de 2014, foi submetida a avaliações clínicas e neurológicas. Os principais instrumentos para avaliação de depressão foram: Entrevista Clínica Estruturada para DSM-4 eixo 1 (SCID-I) e Questionário de Saúde do Paciente - versão 9 itens (PHQ-9); e para comprometimento cognitivo: Entrevista Telefônica Modificada para Estado Cognitivo (TICS-M), aplicados em 1-3 meses, 6 meses e anualmente até 2 anos. Além da quantificaçao da DPA e PC e fatores associados em 1-3 meses (fase subaguda), na fase crônica foram realizadas análises de sobrevida pelas curvas de Kaplan-Meier e modelos de regressão logística de Cox (Razão de Risco - RR, interval de confiança- IC95%) para investigar a progressão de DPA ou PC aos 6 meses e 2 anos, de acordo com lateralidade do AVC. RESULTADOS: Dos 103 pacientes elegíveis, 85,4% apresentaram AVC isquêmico e 73,7% foram diagnosticados como primeiro evento. Na fase subaguda, 27,2% apresentaram PC e 13,6% apresentaram DPA (5,8% com \"primeiro episódio\" e 7,8% com depressão \"recorrente\"). DPA e/ou PC foram associados com baixa escolaridade, gênero feminino e idade entre 55 e 74 anos. Em 1-3 meses pós-AVC, a lesão cerebral do hemisfério esquerdo foi mais frequentemente associada ao aumento do PC do que à lesão à direita (71,4% vs. 28,4%, p = 0,005). A DPA não esteve associada à lateralidade do AVC. No geral, os níveis de biomarcadores não apresentaram alterações nos pacientes XX com DPA e PC. No seguimento até 2 anos, foi encontrada uma frequência de 19% de DPA e 38% de PC. A maioria dos participantes (53%) apresentou AVC no hemisfério direito, entretanto o AVC neste hemisfério não esteve associado com DPA ou PC. Confirmando os dados observados em 1-3 meses pós-evento, o AVC do lado esquerdo foi um preditor independente de PC em longo prazo, mas não de DPA. O AVC esquerdo foi associado a uma alta probabilidade de PC (42,6% e 53,2%, respectivamente, aos 6 meses e 2 anos, p-log-rank: 0,002). A RR de PC por AVC à esquerda foi de 3,38 (IC95%, 1,35-8,50) aos 6 meses e foi mantida aos 2 anos (RR 3,38; IC95%, 1,50-7,59). CONCLUSÕES: PC associou-se a uma menor escolaridade, sexo feminino e faixa etária entre 55 a 74 anos. O AVC no hemisfério esquerdo esteve associado a uma maior frequência de PC, apresentando um risco 3 vezes maior para o desenvolvimento de PC ao longo de 2 anos após o AVC / INTRODUCTION: Stroke, depression and cognitive impaiment are comorbidities associated with the high burden of disability worldwide. Depression and cognitive impairment are responsible for increased post-stroke morbidity and mortality. OBJECTIVE: To investigate the cerebrovascular risk factors associated with the development of post-stroke depression (PSD) and post-stroke cognitive impairment (PCI) based on brain magnetic resonance imaging (MRI) and biomarkers (serotonin, BDNF, IL-6, IL-18) in the subacute phase (1-3 months) and in the chronic phase (up to 2 years of follow-up) after stroke in survivors of the Stroke Mortality and Morbidity Study (EMMA), São Paulo, Brazil. METHODS: Stroke participants prospectively admitted at HU-USP Emergency Department from April 2006 to November 2014 underwent clinical and neurological evaluations. The main instruments for evaluation of depression were: Structured Clinical Interview for DSM-4 axis 1 (SCID-I) and Patient Health Questionnaire version 9 items (PHQ-9); and cognitive impairment: Modified Telephone Interview for Cognitive Status (TICS-M), applied in 1-3 months, 6 months and annually up to 2 years. In addition of the quantification of PSD and PCI and associated factors in 1-3 months (subacute phase), survival analyzes were performed on Kaplan-Meier curves and Cox logistic regression models (Hazard Ratio-HR, confidence interval-95% CI) to investigate the progression of PSD or PCI at 6 months and 2 years, according to laterality of the stroke. RESULTS: Of the 103 eligible patients, 85.4% had ischemic stroke and 73.7% had a stroke for the first time. In the subacute phase, 27.2% had PCI and 13.6% had current PSD (5.8% with \"first episode\" and 7.8% with \"recurrent\" depression). PSD and / or PCI were associated with low educational level, female gender and 55-74 years old. In 1-3 months, left-sided stroke was more frequently associated with an increase in PCI than right lesion (71.4% vs. 28.4%, p = 0.005). PSD was not associated with laterality of the stroke. Overall, biomarkers levels did not show changes in patients with PSD and PCI. Up to 2 years follow-up, it was found a frequency of 19% of DPA and 38% of PCI. Most participants (53%) presented right-sided stroke, however, it was not associated with PSD or PCI. Confirming the observed data at 1-3 months post-event, left-sided stroke XXI I was an independent predictor of long-term PCI but not PSD. Left-sided stroke was associated with a high probability of PCI (42.6% and 53.2%, respectively at 6 months and 2 years, p-log rank: 0.002). The risk ratio (RR) of PCI due to left-sided stroke was 3.38 (95% CI, 1.35-8.50) at 6 months and maintained at 2 years (RR 3.38, 95% CI, 1, 50-7.59). CONCLUSIONS: PCI was associated with lower educational level, female gender and age group between 55 and 74 years. Stroke in the left hemisphere was associated with a higher frequency of PCI and the risk of developing cognitive impairment over 2 years after stroke was 3

INTRODUÇÃO: A forma clássica de encefalomiopatia mitocondrial associada à mutação do DNA mitocondrial m.3243A>G é a Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-like episodes (síndrome de MELAS). Entretanto, o espectro de manifestações clínicas dos indivíduos que apresentam essa mutação é bastante amplo. OBJETIVO: Descrever o espectro clínico, laboratorial e de imagem de pacientes com doença mitocondrial decorrente da mutação m.3243A>G. MÉTODOS: Estudo descritivo retrospectivo de uma série de casos de pacientes com a mutação m.3243A>G em seguimento no ANEM/HCFMRP-USP. Os dados clínicos e informações sobre exames complementares foram coletados através de revisão sistemática dos prontuários médicos dos pacientes selecionados. Os exames de neuroimagem foram revisados juntamente com neurorradiologista experiente para descrição das lesões encontradas. RESULTADOS: No período compreendido entre maio de 2000 e maio de 2015, a mutação m.3243A>G foi pesquisada em um total de 817 pacientes, em DNA extraído de células do sangue periférico (n= 441), de fragmentos de biópsia de músculo esquelético (n= 293), de ambos (n= 82) e mais raramente de células do sedimento urinário (n=1). Dentre esses, 16 indivíduos de 12 famílias apresentaram a referida mutação, resultando em uma taxa de detecção da mutação de 1,96% nessa população. Foram incluídos no estudo 12 indivíduos de 9 famílias que estavam em seguimento no nosso serviço. Os achados mais comuns nesta série foram em ordem de frequência: sinais de miopatia, transtornos neurocomportamentais, epilepsia, endocrinopatias, ataxia cerebelar, migrânea, episódios semelhantes a AVC, vômitos recorrentes, distúrbios de condução cardíaca, neuropatia periférica e sinais de disautonomia, mioclonias, surdez neurossensorial, cegueira cortical, comprometimento ocular, e proteinúria. Em nossa série, identificamos que cinco pacientes foram classificados com a forma clássica de MELAS, dois apresentaram CPEO associada a outros sintomas como transtornos psiquiátricos e diabetes mellitus. Os demais pacientes apresentavam características clínicas que não configuravam uma síndrome clinica definida. Além das lesões semelhantes a AVC, as lesões reveladas por neuroimagem mais frequentes nessa população foram alteração de sinal dos núcleos da base, atrofia encefálica e alteração de sinal da substância branca, sendo igualmente prevalentes entre os pacientes com a síndrome clássica de MELAS e os pacientes que não apresentaram lesões semelhantes a AVC. Dos pacientes com MELAS, 100% apresentaram pico anômalo de lactado e 60% redução do NAA à espectroscopia de prótons; enquanto que entre os pacientes sem lesões semelhantes a AVC essas alterações foram encontradas em dois e em um paciente Caracterização clínica, laboratorial e de neuroimagem de pacientes com doença mitocondrial associada à mutação m.3243A>G 8 respectivamente. Nós identificamos o achado inédito de azoospermia associada à mutação m.3243A>G. Essa é a maior série de casos de pacientes brasileiros com a mutação m.3243A>G até o momento. CONCLUSÃO: O amplo espectro de apresentação clínica e de neuroimagem é uma característica notável entre os pacientes com a mutação m.3243A>G do DNAmt. Essa desordem deve ser considerada em pacientes com evidência de sinais e sintomas que sugiram acometimento multissistêmico. / INTRODUCTION: The classic form of mitochondrial encephalomyopathy associated with m.3243A>G mutation is the Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-like episodes (MELAS syndrome). However, the spectrum of clinical manifestations of patients with this mutation is quite wide. OBJECTIVE: To describe the clinical, laboratory and imaging spectrum of patients with mitochondrial disease due to m.3243A>G mutation METHODS: A retrospective descriptive study of a series of cases of patients with the m.3243A>G mutation in follow-up in ANEM/HCFMRP-USP. Clinical data and information about additional tests were collected through systematic review of medical records of selected patients. Neuroimaging studies were reviewed with supervision of experienced neuroradiologist and the lesions were described. RESULTS: Between May 2000 and May 2015, the mutation m.3243A>G was evaluated in a total of 817 patients, on DNA extracted from peripheral blood (n = 441), skeletal muscle biopsy samples (n = 293), both (n = 82) and more rarely urinary sediment cells (n = 1). We founded 16 individuals 12 families with the mutation, resulting in a mutation detection rate of 1.96 % that population. 12 individuals from nine families, who were following at our service, were included in this study. The most common findings in this series were in order of frequency: myopathy signs, neurobehavioral disorders, epilepsy, endocrine disorders, cerebellar ataxia, migraine, stroke-like episodes, recurrent vomiting, cardiac conduction disorders, peripheral neuropathy and signs of dysautonomia, myoclonus, sensorineural deafness, cortical blindness, uveitis, and proteinuria. In our series, we found that five of the patients were classified with the classical MELAS syndrome, two patients had CPEO associated with other symptoms such as psychiatric disorders and diabetes mellitus. The remaining patients had other features of mitochondrial disease not consistent with another recognised syndrome. In addition to stroke-like lesions, the more frequent lesions revealed in neuroimaging studies were deep gray matter changes, brain atrophy and white matter changes. These changes had similar prevalences between the patients with the classic syndrome of MELAS and patients who did not have stroke-like lesions. All patients with classical MELAS have lactate peak and 60% of them have reduction of NAA at spectroscpopy; while these changes were found in two and one patient respectively, in the group of patients without stroke-like lesions. We identified azoospermia in one paciente with classic MELAS, a finding not previously associated with m.3243A>G. At moment, this is the largest Brazilian case series of patients with the m.3243A>G mutation. Clinical, laboratory and neuroimaging features of patients with mitochondrial disease associated with mutation m.3243A > G 10 CONCLUSION: The wide spectrum of clinical presentation and neuroimaging is a notable feature among patients with the mutation m.3243A> G mtDNA. This disorder should be considered in patients with evidence of signs and symptoms suggestive of multisystem involvement.

INTRODUÇÃO: Acidente vascular cerebral (AVC), depressão e prejuízo cognitivo são comorbidades associadas à alta carga mundial de incapacidade. Depressão e prejuízo cognitivo são condições que ocorrem mais frequentemente em pacientes pós-AVC e estão associadas a um aumento da morbimortalidade. OBJETIVO: Investigar potenciais fatores de risco cerebrovasculares associados ao desenvolvimento de depressão pós-AVC (DPA) e prejuízo cognitivo pós-AVC (PC) com base na neuroimagem por ressonância magnética cerebral (RM) e biomarcadores (serotonina, BDNF, IL-6, IL-18) na fase subaguda (1-3 meses) e na fase crônica (até 2 anos de seguimento) após o AVC em sobreviventes do Estudo de Mortalidade e Morbidade do AVC (EMMA), São Paulo, Brasil. MÉTODOS: Amostra de participantes admitidos por AVC no Departamento de Emergências do HU-USP, de abril de 2006 a novembro de 2014, foi submetida a avaliações clínicas e neurológicas. Os principais instrumentos para avaliação de depressão foram: Entrevista Clínica Estruturada para DSM-4 eixo 1 (SCID-I) e Questionário de Saúde do Paciente - versão 9 itens (PHQ-9); e para comprometimento cognitivo: Entrevista Telefônica Modificada para Estado Cognitivo (TICS-M), aplicados em 1-3 meses, 6 meses e anualmente até 2 anos. Além da quantificaçao da DPA e PC e fatores associados em 1-3 meses (fase subaguda), na fase crônica foram realizadas análises de sobrevida pelas curvas de Kaplan-Meier e modelos de regressão logística de Cox (Razão de Risco - RR, interval de confiança- IC95%) para investigar a progressão de DPA ou PC aos 6 meses e 2 anos, de acordo com lateralidade do AVC. RESULTADOS: Dos 103 pacientes elegíveis, 85,4% apresentaram AVC isquêmico e 73,7% foram diagnosticados como primeiro evento. Na fase subaguda, 27,2% apresentaram PC e 13,6% apresentaram DPA (5,8% com \"primeiro episódio\" e 7,8% com depressão \"recorrente\"). DPA e/ou PC foram associados com baixa escolaridade, gênero feminino e idade entre 55 e 74 anos. Em 1-3 meses pós-AVC, a lesão cerebral do hemisfério esquerdo foi mais frequentemente associada ao aumento do PC do que à lesão à direita (71,4% vs. 28,4%, p = 0,005). A DPA não esteve associada à lateralidade do AVC. No geral, os níveis de biomarcadores não apresentaram alterações nos pacientes XX com DPA e PC. No seguimento até 2 anos, foi encontrada uma frequência de 19% de DPA e 38% de PC. A maioria dos participantes (53%) apresentou AVC no hemisfério direito, entretanto o AVC neste hemisfério não esteve associado com DPA ou PC. Confirmando os dados observados em 1-3 meses pós-evento, o AVC do lado esquerdo foi um preditor independente de PC em longo prazo, mas não de DPA. O AVC esquerdo foi associado a uma alta probabilidade de PC (42,6% e 53,2%, respectivamente, aos 6 meses e 2 anos, p-log-rank: 0,002). A RR de PC por AVC à esquerda foi de 3,38 (IC95%, 1,35-8,50) aos 6 meses e foi mantida aos 2 anos (RR 3,38; IC95%, 1,50-7,59). CONCLUSÕES: PC associou-se a uma menor escolaridade, sexo feminino e faixa etária entre 55 a 74 anos. O AVC no hemisfério esquerdo esteve associado a uma maior frequência de PC, apresentando um risco 3 vezes maior para o desenvolvimento de PC ao longo de 2 anos após o AVC / INTRODUCTION: Stroke, depression and cognitive impaiment are comorbidities associated with the high burden of disability worldwide. Depression and cognitive impairment are responsible for increased post-stroke morbidity and mortality. OBJECTIVE: To investigate the cerebrovascular risk factors associated with the development of post-stroke depression (PSD) and post-stroke cognitive impairment (PCI) based on brain magnetic resonance imaging (MRI) and biomarkers (serotonin, BDNF, IL-6, IL-18) in the subacute phase (1-3 months) and in the chronic phase (up to 2 years of follow-up) after stroke in survivors of the Stroke Mortality and Morbidity Study (EMMA), São Paulo, Brazil. METHODS: Stroke participants prospectively admitted at HU-USP Emergency Department from April 2006 to November 2014 underwent clinical and neurological evaluations. The main instruments for evaluation of depression were: Structured Clinical Interview for DSM-4 axis 1 (SCID-I) and Patient Health Questionnaire version 9 items (PHQ-9); and cognitive impairment: Modified Telephone Interview for Cognitive Status (TICS-M), applied in 1-3 months, 6 months and annually up to 2 years. In addition of the quantification of PSD and PCI and associated factors in 1-3 months (subacute phase), survival analyzes were performed on Kaplan-Meier curves and Cox logistic regression models (Hazard Ratio-HR, confidence interval-95% CI) to investigate the progression of PSD or PCI at 6 months and 2 years, according to laterality of the stroke. RESULTS: Of the 103 eligible patients, 85.4% had ischemic stroke and 73.7% had a stroke for the first time. In the subacute phase, 27.2% had PCI and 13.6% had current PSD (5.8% with \"first episode\" and 7.8% with \"recurrent\" depression). PSD and / or PCI were associated with low educational level, female gender and 55-74 years old. In 1-3 months, left-sided stroke was more frequently associated with an increase in PCI than right lesion (71.4% vs. 28.4%, p = 0.005). PSD was not associated with laterality of the stroke. Overall, biomarkers levels did not show changes in patients with PSD and PCI. Up to 2 years follow-up, it was found a frequency of 19% of DPA and 38% of PCI. Most participants (53%) presented right-sided stroke, however, it was not associated with PSD or PCI. Confirming the observed data at 1-3 months post-event, left-sided stroke XXI I was an independent predictor of long-term PCI but not PSD. Left-sided stroke was associated with a high probability of PCI (42.6% and 53.2%, respectively at 6 months and 2 years, p-log rank: 0.002). The risk ratio (RR) of PCI due to left-sided stroke was 3.38 (95% CI, 1.35-8.50) at 6 months and maintained at 2 years (RR 3.38, 95% CI, 1, 50-7.59). CONCLUSIONS: PCI was associated with lower educational level, female gender and age group between 55 and 74 years. Stroke in the left hemisphere was associated with a higher frequency of PCI and the risk of developing cognitive impairment over 2 years after stroke was 3

Les objectifs de cette thèse étaient de caractériser les corrélats neuronaux fonctionnels et structurels de l'abolition de la conscience observés pendant le coma et d'identifier les signatures neuronales précoces de la récupération neurologique à partir de cet état. Pour atteindre ce but, nous avons étudié des patients cérébrolésés, recrutés au stade aigu du coma, à l'aide de l'IRM fonctionnelle au repos et IRM structurale. Nos résultats indiquent une réorganisation topologique globale du cerveau des patients, reflétée par une dédifférenciation et une réduction de la résilience des réseaux fonctionnels au repos d'ordre élevé. Ces anomalies sont accompagnées d'une perte de connexions fronto-pariétales à longue distance. Au niveau régional, nous avons observé un schéma complexe de diminution et d'augmentation de la densité de connexion fonctionnelle entre le cortex postéromédial et le cortex préfrontal médial : régions précédemment décrites pour avoir un rôle critique dans la conscience. De manière intéressante, ces modifications de densité de connexion étaient significativement liées à la récupération des patients trois mois après le coma. Enfin, l'analyse multimodale a permis de démontrer une association significative entre la connectivité fonctionnelle et l'intégrité structurelle cérébrales antéro-postérieure, fournissant des informations importantes sur le lien structure/fonction au décours de ces troubles acquis de la conscience. / The aim of the present thesis was to characterize the functional and structural neural correlates of acute consciousness abolition induced by severe brain injury and identify early neural signatures of long-term neurological recovery. To do so, we studied brain-injured patients, recruited in the acute stage of coma, using resting-state functional and structural MRI. Our findings indicated a global topological brain reorganization in coma patients, reflected in dedifferentiated and less resilient high-order resting-state functional networks, paralleled with a loss of long-range fronto-parietal connections. On a regional level, we found a complex pattern of voxel-wise decrease and increase in functional connection density between the posteromedial cortex and the medial prefrontal cortex, regions previously described to have a critical role in conscious processing. These connection density patterns seemed to permit outcome prediction in patients, assessed three months post-coma. Furthermore, the multi-modal MRI analysis demonstrated a significant association between antero-posterior functional connectivity and structural integrity, providing further insights into the pathological underpinning of conscious processing.

Objetivo: avaliar as diferenças estruturais e funcionais entre o cérebro de pacientes com tontura postural-perceptual persistente (TPPP) e controles. Método: o estudo foi aprovado pela comissão de ética local. As voluntárias deram consentimento formal. 16 mulheres com TPPP (44.7±8.3 anos) e 16 controles (46.5±8.5 anos) foram pareadas por sexo e idade. Imagens de ressonância magnética funcional (RMf) e estrutural foram adquiridas utilizando sistema 3.0 T durante a visibilização de figuras padronizadas do International Affective Pictures System (IAPS) com valência negativa, positiva e neutra. Realizou-se análise estrutural segmentar e volumétrica com o programa Freesurfer e funcional com o FSL (FMRIB Software Library) usando correção fatia-tempo e de movimento, suavização espacial (5mm FWHM), e normalização no espaço standard MNI (Montreal Neurological Institute). O modelo linear geral (GLM) incluiu regressores por grupo e condições. Adotou-se um limiar de Z = 3.09 (p < 0.001) para cada vóxel, e um nível de significância para correção de clusters de p < 0.05. O Z=2.3 foi utilizado na comparação entre grupos. Resultados: o grupo com TPPP apresentou ativação na região do córtex cingulado anterior na diferença entre contrastes positivos e negativos por queda de sinal na visibilização de estímulos negativos; enquanto o grupo controle teve efeito BOLD (Blood Oxygen Level Dependent) positivo na região amigdaliana bilateralmente na diferença entre contrastes negativos e positivos. Houve ativação em giro angular esquerdo na diferença entre contrastes negativos e positivos e entre grupos (pacientes > controles). Conclusão: ativação em região amigdaliana em resposta a estímulos negativos em relação aos positivos é frequentemente encontrada em pacientes com ansiedade e síndrome do estresse pós-traumático, mas não foi vista no nosso grupo com TPPP, só no controle. Por outro lado, o grupo com TPPP mostrou desativação da região do córtex cingulado anterior, um modelo descrito em algumas, mas não em todas as disfunções ansiosas, e não identificado no grupo controle. Além disto, o efeito BOLD positivo na região do giro angular esquerdo, área não inclusa no sistema límbico, com múltiplas funções, dentre elas a orientação espacial, indicam que mais trabalhos são necessários para elucidar o mecanismo cerebral da TPPP / Objectives: evaluate structural and functional differences in brain among patients with postural perceptual persistent dizziness (PPPD) and controls. Method: The study was approved by local IRB, and volunteers gave their informed consent. Sixteen women with PPPD (44.7 ± 8.3 years-old) were compared to 16 controls (46.5 ± 8.5 years-old) matched by age and gender. Structural and functional brain images were acquired in a 3.0T MRI system while subjects were presented with pictures from a standard reference (International Affective Pictures System - IAPS) with positive, neutral and negative emotional valence stimuli. Structural images were analysed in Freesurfer program and fMRI images in FSL (FMRIB Software Library) using slice-time and motion correction, spatial smoothing (5mm FWHM), and normalized images into MNI standard space. The GLM model included regressors for groups and conditions. A threshold Z-score = 3.09 (p < 0.001) was used for each voxel, and was adopted the correction by clusters at a p < 0.05 significance level. A Z-score = 2.3 was used for comparison between groups. Results: the PPPD group showed increased brain response at anterior cingulate cortex when comparing [positive > negative] stimuli as a result of deactivation during negative stimuli, whereas the control group had positive BOLD when comparing [negative > positive] stimuli at amigdala region in both sides. PPPD group had increased brain response when comparing [negative>positive] stimuli and [patients > controls] in the left angular gyrus. Conclusion: The amygdala region activation in control group in response to negative than positive stimuli is a pattern often found in patients with anxiety and traumatic stress but not was seen in our patient group. In contrast, they showed deactivation of the anterior cingulate cortex in response to negative stimuli, a pattern found in some, but not all anxiety disorders, and not identified in the control group. Otherwise, the positive BOLD in angular gyrus, brain area not included in limbic system, with multiple functions, including spatial orientation, indicate that more work is needed to elucidate brain mechanisms underlying PPPD

INTRODUÇÃO: A forma clássica de encefalomiopatia mitocondrial associada à mutação do DNA mitocondrial m.3243A>G é a Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-like episodes (síndrome de MELAS). Entretanto, o espectro de manifestações clínicas dos indivíduos que apresentam essa mutação é bastante amplo. OBJETIVO: Descrever o espectro clínico, laboratorial e de imagem de pacientes com doença mitocondrial decorrente da mutação m.3243A>G. MÉTODOS: Estudo descritivo retrospectivo de uma série de casos de pacientes com a mutação m.3243A>G em seguimento no ANEM/HCFMRP-USP. Os dados clínicos e informações sobre exames complementares foram coletados através de revisão sistemática dos prontuários médicos dos pacientes selecionados. Os exames de neuroimagem foram revisados juntamente com neurorradiologista experiente para descrição das lesões encontradas. RESULTADOS: No período compreendido entre maio de 2000 e maio de 2015, a mutação m.3243A>G foi pesquisada em um total de 817 pacientes, em DNA extraído de células do sangue periférico (n= 441), de fragmentos de biópsia de músculo esquelético (n= 293), de ambos (n= 82) e mais raramente de células do sedimento urinário (n=1). Dentre esses, 16 indivíduos de 12 famílias apresentaram a referida mutação, resultando em uma taxa de detecção da mutação de 1,96% nessa população. Foram incluídos no estudo 12 indivíduos de 9 famílias que estavam em seguimento no nosso serviço. Os achados mais comuns nesta série foram em ordem de frequência: sinais de miopatia, transtornos neurocomportamentais, epilepsia, endocrinopatias, ataxia cerebelar, migrânea, episódios semelhantes a AVC, vômitos recorrentes, distúrbios de condução cardíaca, neuropatia periférica e sinais de disautonomia, mioclonias, surdez neurossensorial, cegueira cortical, comprometimento ocular, e proteinúria. Em nossa série, identificamos que cinco pacientes foram classificados com a forma clássica de MELAS, dois apresentaram CPEO associada a outros sintomas como transtornos psiquiátricos e diabetes mellitus. Os demais pacientes apresentavam características clínicas que não configuravam uma síndrome clinica definida. Além das lesões semelhantes a AVC, as lesões reveladas por neuroimagem mais frequentes nessa população foram alteração de sinal dos núcleos da base, atrofia encefálica e alteração de sinal da substância branca, sendo igualmente prevalentes entre os pacientes com a síndrome clássica de MELAS e os pacientes que não apresentaram lesões semelhantes a AVC. Dos pacientes com MELAS, 100% apresentaram pico anômalo de lactado e 60% redução do NAA à espectroscopia de prótons; enquanto que entre os pacientes sem lesões semelhantes a AVC essas alterações foram encontradas em dois e em um paciente Caracterização clínica, laboratorial e de neuroimagem de pacientes com doença mitocondrial associada à mutação m.3243A>G 8 respectivamente. Nós identificamos o achado inédito de azoospermia associada à mutação m.3243A>G. Essa é a maior série de casos de pacientes brasileiros com a mutação m.3243A>G até o momento. CONCLUSÃO: O amplo espectro de apresentação clínica e de neuroimagem é uma característica notável entre os pacientes com a mutação m.3243A>G do DNAmt. Essa desordem deve ser considerada em pacientes com evidência de sinais e sintomas que sugiram acometimento multissistêmico. / INTRODUCTION: The classic form of mitochondrial encephalomyopathy associated with m.3243A>G mutation is the Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-like episodes (MELAS syndrome). However, the spectrum of clinical manifestations of patients with this mutation is quite wide. OBJECTIVE: To describe the clinical, laboratory and imaging spectrum of patients with mitochondrial disease due to m.3243A>G mutation METHODS: A retrospective descriptive study of a series of cases of patients with the m.3243A>G mutation in follow-up in ANEM/HCFMRP-USP. Clinical data and information about additional tests were collected through systematic review of medical records of selected patients. Neuroimaging studies were reviewed with supervision of experienced neuroradiologist and the lesions were described. RESULTS: Between May 2000 and May 2015, the mutation m.3243A>G was evaluated in a total of 817 patients, on DNA extracted from peripheral blood (n = 441), skeletal muscle biopsy samples (n = 293), both (n = 82) and more rarely urinary sediment cells (n = 1). We founded 16 individuals 12 families with the mutation, resulting in a mutation detection rate of 1.96 % that population. 12 individuals from nine families, who were following at our service, were included in this study. The most common findings in this series were in order of frequency: myopathy signs, neurobehavioral disorders, epilepsy, endocrine disorders, cerebellar ataxia, migraine, stroke-like episodes, recurrent vomiting, cardiac conduction disorders, peripheral neuropathy and signs of dysautonomia, myoclonus, sensorineural deafness, cortical blindness, uveitis, and proteinuria. In our series, we found that five of the patients were classified with the classical MELAS syndrome, two patients had CPEO associated with other symptoms such as psychiatric disorders and diabetes mellitus. The remaining patients had other features of mitochondrial disease not consistent with another recognised syndrome. In addition to stroke-like lesions, the more frequent lesions revealed in neuroimaging studies were deep gray matter changes, brain atrophy and white matter changes. These changes had similar prevalences between the patients with the classic syndrome of MELAS and patients who did not have stroke-like lesions. All patients with classical MELAS have lactate peak and 60% of them have reduction of NAA at spectroscpopy; while these changes were found in two and one patient respectively, in the group of patients without stroke-like lesions. We identified azoospermia in one paciente with classic MELAS, a finding not previously associated with m.3243A>G. At moment, this is the largest Brazilian case series of patients with the m.3243A>G mutation. Clinical, laboratory and neuroimaging features of patients with mitochondrial disease associated with mutation m.3243A > G 10 CONCLUSION: The wide spectrum of clinical presentation and neuroimaging is a notable feature among patients with the mutation m.3243A> G mtDNA. This disorder should be considered in patients with evidence of signs and symptoms suggestive of multisystem involvement.

Os fatores de risco cardiovascular (FRCV) podem estar associados com pior funcionamento cognitivo em idosos e afetar a estrutura cerebral. Usando ressonância magnética (RM) e morfometria baseada em voxel (voxel-based morphometry; VBM), foram avaliados neste estudo volumes regionais de substância branca (SB) cerebral em uma amostra de base populacional de indivíduos saudáveis com idades entre 65-75 anos (n = 156). Usando o escore de risco de Framingham (ERF) como índice de risco cardiovascular, subdividimos a amostra total em três subgrupos de acordo com a gravidade de FRCV. Comparamos os volumes regionais cerebrais de SB entre estes grupos, e investigamos a relação entre volume de SB e desempenho cognitivo. Por fim, dada a possível influência de variações no gene que codifica a apoliproteína E (APOE) sobre cognição, anatomia cerebral e FRCV, avaliamos possíveis mudanças nos resultados das análises volumétricas cerebrais dependendo da presença do alelo APOE?4. No subgrupo de alto risco, detectamos clusteres com volume significativamente menor de SB na região pré-frontal direita dorsolateral juxtacortical em comparação com ambos os subgrupos de baixo e médio risco cardiovascular. Estes achados permaneceram os mesmos quando a análise estatística levou em conta a presença do alelo APOE?4 como covariável de confusão. O desempenho em tarefa cognitiva de controle inibitório foi inversamente correlacionado com o volume de SB pré-frontal direita, em proporção direta com o grau de risco cardiovascular. Redução significativa na SB parietal profunda também foi detectada bilateralmente no subgrupo de alto RCV em comparação com os outros dois subgrupos. Este é o primeiro estudo de VBM usando amostra grande de idosos a documentar a topografia de déficits volumétricos de SB associados com alto ERF em todo o cérebro. A associação significativa entre menor volume de SB e pior desempenho cognitivo em termos de resposta inibitória indica que as mudanças de volume de SB pré-frontal relacionadas com FRCV são clinicamente significativas, uma vez que o controle inibitório é uma operação cognitiva amplamente reconhecida por depender da integridade cortical pré-frontal / Cardiovascular risk factors (CVRF) may be associated with poor cognitive functioning in elderlies and affect brain structure. Using magnetic resonance imaging (MRI) and voxel-based morphometry (VBM), we assessed regional white matter (WM) volumes in a population-based sample of healthy individuals aged 65-75 years (n=156). Using the Framingham Risk Score (FRS) to assess the severity of CVRF, we subdivided the sample in three subgroups. We compared regional WM volumes in the brain between these subgroups, and investigated the relationship between WM volumes and cognitive performance. Also, given the possible influence of variations in the gene that code the apoliprotein E (APOE) on cognition, brain anatomy and CVRF, we evaluate changes in the results of our volumetric analysis depending on the presence of the APOE?4 allele. In the high-risk subgroup, we detected one cluster of significantly reduced WM volume in the right juxtacortical dorsolateral prefrontal region compared to both low- and intermediate-risk subgroups. This finding remained unchanged when the analysis was repeated taking into account the presence of the APOE?4 allele as a confounding covariate. Inhibitory control performance was negatively related to right prefrontal WM volume, in direct proportion to the degree of CVRF. Significantly reduced deep parietal WM was also detected bilaterally in the high-risk CVRF subgroup. This is the first large VBM study documenting the topography of WM volume deficits associated with high FRS across the whole brain. The significant association regarding poor response inhibition indicates that prefrontal WM volume changes related to CVR are clinically meaningful, since inhibitory control is a cognitive operation widely known to rely on prefrontal cortical integrity

A neuroimaging feature extraction model is designed to extract region-based image features whose values are predicted by base learners trained on raw neuroimaging morphological variables. The main objectives are to identify Alzheimer’s disease (AD) in its earliest manifestations, and be able to predict and gauge progression of the disease through the stages of mild cognitive impairment (EMCI), late MCI (LMCI) and AD. The model was evaluated on the ADNI database and showed 75.26% accuracy for the challenging EMCI diagnosis based on the 10-fold cross-validation. Our approach also performed well for the other binary classifications: EMCI vs. LMCI (72.3%), EMCI vs. AD (95%), LMCI vs. AD (84.3%), CN vs. LMCI (77.5%), and CN vs. AD (96.5%). By applying the model to the Genome-wide Association Study, along with the sparse Partial Least Squares regression method, we successfully detected risk genes such as the APOE, TOMM40, RVRL2 and APOC1 along with the new finding of rs917100. Moreover, the research aimed to investigate the relationship of different biomarkers; especially the imaging biomarkers to better understand the precise biologic changes that characterize Alzheimer’s disease. The unique and independent contribution of APOE4 allele status (E4+\E4-), amyloid (Aβ) load status (Amy+\Amy-) and combined APOE4 and Aβ status on regional cortical thickness (CTh) and cognition were evaluated via a series of two-way ANCOVAs with post-hoc Tukey HSD tests. Results showed that decreased CTh is independently associated with Amy+ status in many brain regions, but with E4+ status in very restricted number of brain regions. Among CN and EMCI participants, E4+ status is associated with increased CTh, in medial and inferior temporal regions. Diverging association patterns of global and regional Aβ load with cortical volume were found in the entorhinal, temporal pole and parahippocampal regions, which were positively associated with regional Aβ load, but with a negative correlation for global Aβ load in MCI stages. In addition, strong positive correlations were shown between baseline regional CTh and the difference of CTh in each region between the CN and AD, even after adjusting for the regional Aβ and APOE genotype (E4+: r = 0.521 and E4-: r = 0.694).

<p>The central theme of the present thesis revolves around the exploration of similarities and differences in brain activity patterns invoked by the component processes underlying mnemonic, executive and attentional functions. The primary aim was to identify and functionally characterize commonly recruited brain regions in terms of shared component processes, which has been a largely neglected area of research in cognitive neuroscience. The vast majority of functional brain imaging investigations of cognition has focused on delineating differences between cognitive functions or processes, with the purpose of isolating the unique functional neuroanatomy that underlies specific cognitive domains. By contrast, the present thesis builds on the results from three imaging studies that focused primarily on detecting commonalities in functional brain activity across different forms of memory processes. In study I, the imaging data from two positron emission tomography (PET) experiments were re-analyzed to identify common activation patterns associated with nine different memory tasks incorporated across the experiments, three each separately indexing working memory, episodic memory, and semantic memory. A generic prefrontal cortex (PFC) network involving discrete subregions of the left hemisphere located in ventrolateral (BA 45/47), dorsolateral (BA 9/44/46), and frontopolar (BA 10) sectors of PFC, as well as a midline portion of the frontal lobes, encompassing the dorsal part of the anterior cingulate cortex (ACC) (BA 24/32), was conjointly recruited across all tasks. In study II, we used a novel mixed blocked/event-related functional magnetic resonance imaging (fMRI) design, which enables separation of brain responses associated with different temporal dynamics to further investigate commonalities of neural activation across working memory, episodic memory, semantic memory, and attention/vigilance. A similar set of common PFC regions, as that discovered in Study I, was found to elicit overlapping brain activity across all memory tasks, with a subset of regions also activated in the attention/vigilance task. Furthermore, the task-induced brain activity was dissociated in terms of the temporal profiles of the evoked neural responses. A common pattern of sustained activity seen across all memory tasks and the attention task involved bilateral (predominantly right-lateralized) ventrolateral PFC (BA 45/47), and the dorsal ACC (BA 24/32), which was assumed to reflect general processes of attention/vigilance. A pattern of sustained activity elicited in all memory tasks, in the absence of attention-related activity, involved the right frontopolar cortex (BA 10), which was assumed to reflect control processes underlying task set maintenance. In addition, common transient activation evoked in the memory tasks relative to the attention task was found in the dorsolateral (BA 9/44) and ventrolateral (BA 47) PFC, the superior parietal cortex (BA 7), and cerebellum. In study III, a mixed fMRI design was used to assess the degree of common brain activity associated with increased executive demand, which was independently manipulated within episodic and working memory. Unitary control modulations involved a shared tonic executive component subserved by fronto-striatal-cerebellar circuitry, assumed to govern top-down context processing throughout task periods, and a stimulus-synchronous phasic component mediated by the intraparietal sulcus (BA 7), assumed to support dynamic shifting of the ‘focus of attention’ among internal representations. Collectively, the theoretical implications of shared neural mechanisms are discussed, with a special focus on human memory and its multifaceted relationships with attention and executive control functions. Finally, the presented imaging data are used to outline a tentative hierarchical neurocognitive model that attempts to give an account of how different unitary component processes might work together during cognitive task performance.</p>

<p>The present thesis investigated family history and neurobiology of social phobia. Social phobia is a disabling disorder characterized by a marked fear of scrutiny in a variety of social situations. By using a validated questionnaire, study I related family history of excessive social anxiety to social phobia and avoidant personality disorder in epidemiologically identified probands in the Swedish general population. A two- to threefold increased relative risk of social anxiety was observed for both diagnostic groups. Thus, having an affected family member is associated with approximately a doubled risk for both social phobia and avoidant personality disorder.</p><p>The neurobiological studies explored situational and anticipatory elicited anxiety by means of positron emission tomography and 15O-water. Study II examined the functional neuroanatomy of social anxiety provocation in social phobics and a healthy comparison group during a public speaking task. Social phobia symptomatology was associated with higher neural activity in the amygdaloid complex, i.e. "the alarm system" of the brain, and lower activity in the prefrontal cortex. Study III examined the neural correlates of anxiety elicited by the anticipation of public speaking in individuals with social phobia. Anticipatory anxiety was accompanied by enhanced regional cerebral blood flow in the dorsolateral prefrontal and inferior temporal cortices as well as in the amygdaloid-hippocampal region. Brain blood flow was lower in the temporal pole and in the cerebellum. These results suggest that social phobia has a neuroanatomical basis in a highly sensitive fear network centered in the amygdaloid-hippocampal region and encompassing the prefrontal cortex.</p>