[pt] O para-raios é o principal equipamento de proteção dos transformadores e linhas de transmissão de energia, que estão presentes em todo território nacional, protegendo-os de descargas atmosféricas e sobretensão, evitando grandes perdas de equipamentos e um custo relativamente alto para as concessionárias de energia. O para-raios precisa obter conformidade e certificação em relação à qualidade do material e a suas características de proteção, e um dos ensaios de verificação de desempenho baseia-se na resposta ao impulso de corrente. Contudo, para a realização destes ensaios de desempenho é necessário que haja um sistema de medição acreditado, apto a realizá-los com precisão e rastreabilidade aos padrões de transdutores, ou seja, com níveis de incerteza dentro dos limites aceitáveis, segundo a norma IEC 62475:2010. O Inmetro, que é o Instituto Nacional de Metrologia do Brasil, ainda não possui um Sistema de Medição de Referência (SMR) que possa ser empregado na fiscalização e acreditação de laboratórios que venham a exercer a função de Sistema de Medição Aprovado (SMA), levando a rastreabilidade e conformidade aos padrões de transdutores de corrente elétrica, de modo a produzir equipamentos com confiabilidade e segurança. Assim, essa dissertação faz um levantamento dos níveis de rastreabilidade e um estudo normativo e estrutural de ensaios de impulso de corrente, à luz da norma IEC 62475:2010. / [en] The surge arrester is the main protection equipment of the power transformers and power transmission lines, which are present throughout the country, protecting them from lightnings and overvoltage, avoiding large equipment failures and a relatively high cost for the power companies. The arrester must obtain conformity and certification regarding the quality of the material and its safety features, and one of the performance verification tests is based on the response to current impulses. However, to realize these performance tests it is necessary to have a measurement system accredited to perform this type of test, with accuracy and traceability of the standard transducers, that is, uncertainty levels within acceptable limits according to IEC 62475:2010. The Brazilian National Institute of Metrology ( INMETRO) does not have a Reference Measuring System (RMS) that can be used in the inspection and accreditation of laboratories that will perform as a Approved Measuring System, giving traceability and conformity to the electrical current transducers standards (Shunts or CTs), so as to produce reliable and safe equipments. Thus, this dissertation surveys the traceability levels and the normative and structural landscape regadring current impulse tests based on IEC 62475:2010.

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INTRODUÇÃO: A despeito das graves consequências comportamentais de indivíduos que sofrem de impulso sexual excessivo (ISE), estudos neuropsicológicos são incipientes e trazem resultados controversos. OBJETIVOS: Por meio de um estudo experimental com sujeitos impulsivos sexuais (pacientes) e não impulsivos sexuais (controles) objetivou-se comparar: a tomada de decisão e a flexibilidade cognitiva no estado basal de vigília (tempo \"0\"); a tomada de decisão e flexibilidade cognitiva no tempo \"0\" e pós-estímulo sexual visual (tempo \"1\") em cada grupo (pacientes e controles) e entre os grupos. MÉTODO: O estudo foi desenvolvido no Ambulatório de ISE do Instituto de Psiquiatria (IPq) do HC-FMUSP. A amostra foi constituída por 30 pacientes e 30 controles recrutados através de divulgação na mídia. Homens, brasileiros, com 18 anos ou mais, que preencheram os critérios diagnósticos para ISE (CID-10 - F 52.7) e os critérios de Goodman para dependência de sexo foram incluídos como pacientes; enquanto participantes assintomáticos e que não preencheram os critérios acima foram incluídos como controles. A investigação neuropsicológica da flexibilidade cognitiva se deu por meio da aplicação Wisconsin Card Sort Test (WCST), enquanto a avaliação da tomada de decisão se deu pela aplicação do Iowa Gambling Task (IGT) no tempo \"0\" e tempo \"1\" (após visualização de vídeo erótico por 20 minutos), respeitando um intervalo mínimo de seis meses entre os tempos. Em ambos os tempos foi aplicada a Escala de Compulsividade Sexual, e no tempo \"1\" foi aplicado o Inventário do Desejo e da Excitação Sexual. RESULTADOS: No estado basal, os pacientes apresentaram maior quantidade de respostas corretas, em relação aos controles, no teste que investiga flexibilidade cognitiva (p = 0,01). Quando comparamos o desempenho de ambos os grupos com eles mesmos entre os tempos, observamos que os controles apresentaram melhor desempenho inicial (Bloco 1) na tomada de decisão (p = 0,01), bem como apresentaram mais acertos no teste que avalia flexibilidade cognitiva (p = 0,01) no tempo \"1\". O mesmo não foi observado em relação aos pacientes. Quando comparamos as médias da diferença (tempo \"1\" - tempo \"0\"), entre os grupos, observamos também melhor desempenho dos controles em relação à quantidade de acertos (p = 0,02). CONCLUSÕES: Desde onde sabemos, este é o primeiro estudo avaliando funções executivas em impulsivos sexuais, após exposição a estímulo visual sexual. Quanto à avaliação no estado basal, os pacientes apresentaram melhores resultados na flexibilidade cognitiva, contrariando a hipótese inicial. Controles apresentaram melhores desempenhos na flexibilidade cognitiva e tomada de decisão inicial após exposição ao estímulo visual sexual, quando comparados com os resultados no estado basal. Na análise da diferença de desempenho pós-estímulo visual sexual comparado com o estado basal, entre os grupos, os controles novamente apresentaram melhor desempenho cognitivo. Tais resultados indicam escolhas iniciais menos impulsivas, e melhor flexibilidade cognitiva, após exposição ao estímulo erótico, pelos controles, sugerindo dificuldades de modulação inicial do comportamento, bem como de funções cognitivas, pelos pacientes, diante do estímulo sexual, apoiando nossas hipóteses / INTRODUCTION: Despite the serious behavioral consequences of individuals suffering from excessive sexual drive (ESD), neuropsychological studies are incipient and bring controversial results. OBJECTIVES: Through an experimental study of sexually impulsive subjects (patients) and non-sexually impulsive (control group) our aim was to compare: decision making and cognitive flexibility during basal wakefulness (Time \"0\"); decision making and cognitive flexibility at time \"0\" and after visual sexual stimulation (time \"1\") in each group (patients and control group) and among groups. METHOD: The study was developed at the ESD Clinic of the Psychiatry Institute (IPq), HC-FMUSP. The sample consisted of 30 patients and 30 people in the control group recruited through media coverage. Brazilian men, 18 years and older who met the diagnostic criteria for ISE (ICD - 10 - 52.7 F) and the Goodman criteria for addiction to sex were included as patients; while asymptomatic participants and that did not meet the above criteria were included in the control group. The neuropsychological research of the cognitive flexibility was made by applying the Wisconsin Card Sort Test (WCST), while the evaluation of the decision-making was made through the application of the Iowa Gambling Task (IGT) at time \"0\" and time \"1\" (after viewing an erotic video for 20 minutes), subject to a minimum interval of six months between times. In both times, the Sexual Compulsivity Scale was applied and to time \"1\", we applied the Sexual Arousal and Desire Inventory. RESULTS: During basal wakefulness patients presented a higher number of correct responses compared to the control group, in the test that investigates cognitive flexibility (p = 0.01). When comparing the performance of both groups to each other in between times, we found that the control group had a better initial performance (Block 1) in decision making (p = 0.01) as well as provided more correct answers in the test that evaluates cognitive flexibility (p = 0.01) at time \"1\". The same was not observed in the patients group. When comparing the average of the difference (time \"1\" - time \"0\") between the groups, we noted a better performance in the control group in what concerns the amount of correct responses (p = 0.02). CONCLUSION: As far as we know, this is the first study assessing executive functions in sexual impulsive, after exposure to sexual visual stimuli. As for the evaluation at basal wakefulness, patients presented better results regarding cognitive flexibility, opposite to the initial hypothesis. The control group presented a better performance concerning cognitive flexibility and initial decision making after exposure to sexual visual stimuli, when compared with results during basal wakefulness. When analyzing the performance difference after visual sexual stimulation compared with basal wakefulness in the two groups, the control group, once again, showed better cognitive performance. Such results indicate less impulsive initial choices and better cognitive flexibility after exposure to erotic stimulation in the control group, suggesting difficulties in the initial modulation of behavior, as well ass of cognitive functions, by patients before sexual stimulation, supporting our hypothesis

O jogo patológico é classificado como um transtorno do controle dos impulsos, que envolve a fissura e a impulsividade para jogar, causando prejuízos sociais. Estudos prévios sugeriram que o topiramato poderia ser mais eficaz do que o placebo no tratamento de alguns transtornos relacionados com impulsividade, tais como transtorno de compulsão alimentar periódico, alcoolismo e dependência de cocaína. O principal objetivo deste estudo foi verificar se o topiramato foi superior ao placebo em controlar fissura e reduzir pensamentos e comportamentos relacionados ao jogo. Método: os jogadores patológicos foram aleatoriamente distribuídos em um de dois grupos: o que recebeu topiramato (n=15) e o que recebeu placebo (n=15) por 12 semanas. Durante o estudo, todos os pacientes participaram de quatro sessões psicoeducacionais, baseadas no programa de 12 passos dos jogadores anônimos. A principal variável de desfecho foi a escala G-SAS. As demais variáveis de desfecho foram consideradas secuindárias, sendo as escalas/entrevista: Escala Yale Brown de obsessão e compulsão adaptada para jogo patológico (PG-YBOCS), Timeline Follow-Back (TFB), questionário de crença de jogadores (GBQ), escala de impulsividade de Barratt (BIS-11), escala de impressão clínica global (CGI), escala de adequação social (EAS). Nos resultados, os pacientes que receberam topiramato obtiveram melhora nos escores das escalas: G-SAS, o que implica em redução dos sintomas de fissura e abstinência; PG-YBOCS, que mostrou redução de comportamentos e obsessões relacionados ao jogo; GBQ, que demonstrou redução de crenças supersticiosas e melhora cognitiva e EAS, que mostrou melhora na qualidade de vida. A entrevista TFB mostrou maiores reduções na média de tempo e quantia de dinheiro gasto em jogo no grupo topiramato em relação ao grupo placebo. Conclusão: o uso de topiramato associado a quatro sessões psicoeducacionais foi superior ao uso de placebo associado a quatro sessões psicoeducacionais, na redução de fissura, freqüência, comportamentos, superstições, quantidade de tempo e dinheiro destinados ao jogo, com melhora na qualidade de vida / Pathological gambling is an impulse control disorder that involves craving and impulsivity to gamble and in which gambling thoughts and behaviors may cause social impairment. Previous studies suggested that topiramate could be effective in the treatment of some disorders related to impulsivity, such as binge eating disorder, alcoholism or cocaine addiction. The studys main goal was to verify if topiramate was superior to placebo in controlling craving and reducing thoughts and behaviors related to gambling. Methods: pathological gamblers were randomized to topiramate (n=15) or placebo (n=15) in a 12-week, double-blind placebo controlled trial. During the 12 weeks the patients had four sessions of a program based on the 12 steps of Anonymous Gamblers. The primary outcome measure was the Gambling Symptom Assessment Scale (G-SAS), which evaluates symptoms related to abstinence. As secondary outcome measures it was used the following scales or interviews: Yale Brown Obsessive Compulsive Scale adapted for Pathological Gambling (PG-YBOCS), Timeline Follow-Back Method (TFB), Gamblers Beliefs Questionnaire (GBQ), Barratt Impulsiveness Scale (BIS-11), Clinical Global Impression (CGI), Social Adjustment Scale (SAS). Results: There were statistic robust findings in some of the scales used in this study. The group of patients who took topiramate had improvement in the scores of the G-SAS, which implies reduction in the symptoms of craving and abstinence; PG-YBOCS, which showed reductions in the behaviors and obsessions related to gambling; GBG, which revealed reduction of superstitious thoughts and cognitive improvement, and EAS that showed improvement in the quality of life. TFB showed that the topiramate group had more reductions in the average of time and money spent on gambling than the placebo group. Conclusions: According to the results, topiramate associated with four sessions based in cognitive restructuring were superior to placebo associated with four sessions based in cognitive restructuring in reducing craving, frequency, behaviors and superstitions related to gambling, and amount of time and money used in gambling. Moreover, according to SAS, the group that took topiramate had better improvement in the quality of life than the placebo group

O pensamento de Bergson situa a estética no seio de uma filosofia da natureza, cujo princípio metafísico está longe de qualquer determinismo e do arbítrio do acaso, remetendo-se à irreversibilidade do tempo. Ao invés de disciplina intelectual que busca a natureza da beleza, trata-se, antes, de conduta vital, processo de diferenciação virtual rumo à posição de novidades radicais, podendo ou não desembocar na atividade artística. A arte não é, portanto, um conjunto de atributos atualmente dados ou a prática de habilidades específicas e, sim, um modo de ação que entrelaça os regimes do virtual e do atual sem permitir que a existência se sobreponha à consistência, realizando-se, inclusive, na sua própria abertura. Se o impulso da vida é o que comunica espírito e matéria, inserindo liberdade na necessidade, segue-se que a atividade artística é uma das vias em que desemboca o elã, ao lado dos seres vivos e da expressão mística. A individuação de uma obra implica certos graus de liberdade e níveis de consciência que não se explicam nem pela espécie, nem pelo indivíduo, já que sua contração intuitiva submete a duração do artista a tonalidades não psicológicas e a-subjetivas. Tocado por uma emoção criadora, vai-se realmente do Todo Aberto à colocação de novos mundos. O veículo de ação confunde-se com a própria ação, criatura com criador, de modo que o corpo artístico instaurado é puro transbordamento de vitalidade, consciência de si do tempo. / Bergson's aesthetics lies within a philosophy of nature, whose metaphysical principle is far from any determinism or chance as it refers to the irreversibility of time. Instead of an intellectual discipline that seeks the nature of beauty, it is rather defined by a vital conduct, a process of virtual differentiation towards the position of radical novelties, which may or may not culminate in artistic activity. Therefore, art is not a set of actual attributes or the practice of specific skills; its, on the other hand, a mode of action that interweaves the regimes of the virtual and the actual without allowing its existence to overlap its consistency. Its realization indeed relies in its own opening. If the impulse of life is what communicates spirit and matter, by inserting liberty into necessity, it follows that artistic activity is one of the ways in which the élan flows, alongside living beings and mystical expression. The individuation of a piece involves certain degrees of freedom and levels of consciousness that cannot be explained neither by the species nor by the individual because its intuitive contraction takes the duration of the artist to tones of vitality that are not psychological or subjective. Touched by a creative emotion, one goes from the perspective of the Open Whole to the placement of new worlds. The vehicle of action then merges with the action itself, creature with creator, so that the artistic body is pure overflowing vitality, when time regains consciousness of itself.

Propulsionar cadeira de rodas (CR) está relacionado a altas incidências de dores e lesões em usuários de cadeira de rodas (UCR). Embora seja reconhecida como uma forma de baixa eficiência para se locomover, representa fundamental importância para o desempenho dessas pessoas nas atividades de vida diária, ocupacionais, de lazer e em sua participação social. Ao longo dos estudos sobre a propulsão nas últimas décadas, foi notado recentemente em especial, que a propulsão inicial que retira o sistema usuário-cadeira de rodas do repouso, o colocando em movimento, apresentam a maiores solicitações mecânicas. Considerando que esta situação é executada várias vezes durante o uso típico da cadeira de rodas, torna-a relevante objeto de estudo. Como até o momento, pouco foram os estudos sobre a fase inicial da autopropulsão e que do ponto de vista da neuroativação, esse movimento não foi abordado, este estudo tem como objetivo descrever o gesto da fase inicial da autopropulsão de cadeira de rodas manual de UCR, por meio da eletromiografia, apresentando os níveis atingidos de ativação muscular e o perfil do comportamento de ativação ao longo da execução do gesto da autopropulsão. Para isso foram avaliados oito grupos musculares envolvidos nesse gesto de onze UCR. Os sinais eletromiográficos foram coletados dos oito grupos musculares, simultaneamente, durante a execução de dez propulsões, partindo do repouso, de cada UCR participante da pesquisa. Com relação aos níveis de ativações musculares, foi introduzido um método alternativo de normalização. Esse método consiste na realização do teste de contração isométrica máxima na própria CR. Os resultados foram apresentados em boxplot a fim de demonstrar o pico de ativação bem como a distribuição dos demais níveis de ativação. Como o novo método proposto demonstrou limitações, inviabilizou a interpretação dos resultados quanto as intensidades calculadas. Sobre o perfil de acionamento muscular ao longo da execução da autopropulsão, os resultados foram expostos em gráficos normalizados pelo pico dinâmico e em relação ao período de um ciclo de propulsão, evidenciando o comportamento ativado em cada instante do ciclo. Segundo os resultados dessa segunda metodologia, entre os oito grupos musculares examinados, os que apresentaram os maiores picos de ativação foram: deltoide anterior (80,27%), o peitoral maior (79,27%), os flexores de punho (78,93%) e os extensores de punho (80,65%). Os achados colaboram com estudos anteriores de outros autores de que os principais grupos musculares efetores na propulsão de CR são o deltóide anterior (DA) e peitoral maior (PM). / Propelling wheelchair (CR) is related to high incidences of pain and injury in wheelchair users (WCU). Although this locomotion way be known as low efficient locomotion mode, it represents fundamental importance for these people performance in daily living activities, occupational, leisure and in their social participation. Over the studies course on propulsion in recent decades, it has recently been noted, particularly, that the initial stage of wheelchair propulsion which retires the user-wheelchair system from resting, putting it into motion, presents greater mechanical stresses. It considering this situation is executed several times during the typical wheelchair usage, it makes this relevant study object. As until current moment, there are few studies about initial stage of wheelchair propulsion and, from the neuroactivation point of view, this movement was not approached, this study aims to describe the gesture of initial stage of manual wheelchair propulsion from WCU, across electromyography, presenting the muscular activation levels achieved and the recruited behavior profile during the propulsion gesture execution. For this problem, eight muscle groups involved in this gesture were evaluated from eleven WCU. Electromyographic signals were collected from these eight muscle groups, simultaneously, during ten propulsions execution, starting from resting, of each WCU participant of the research. Regarding the muscular activation levels, an alternative normalization method was introduced. This method consists in performing the maximum isometric contraction test on the wheelchair itself. The results were showed in boxplot in order to demonstrate the activation peak as well as the remaining activation levels distribution. As the new method proposed showed limitations, a better results interpretation was not possible on calculated intensities. Regarding the muscular activation profile during the propulsion execution, the results were exposed in graphs normalized by the dynamic peak as well as in relation to a single propulsion cycle, evidencing the activated behavior at each cycle moment. According to the results based on second methodology, among the eight muscle groups examined, the ones which presented the highest activation peaks values were: the anterior deltoid (80.27%), the pectoralis major (79.27%), the wrist flexors (78, 93%) and the wrist extensors (80.65%). The findings agree with previous studies by other authors that the main effector muscle groups in CR propulsion are anterior deltoid (DA) and pectoralis major (PM).

Mon projet de thèse porte sur les altérations de la réponse dopaminergique dans la maladie de Parkinson (MP). Les troubles moteur de la MP sont améliorés par la L-Dopa (précurseur de la dopamine) et/ou les agonistes dopaminergiques. Cependant, ces traitements engendrent des effets secondaires moteurs (les dyskinésies) et non-moteurs. Ainsi, environ 15% des patients atteints de la MP sous agoniste dopaminergique vont présenter des addictions comportementales avec un syndrome de sevrage, et 3 à 4% des patients traités à la L-Dopa ou à l’apomorphine développent une prise compulsive de médicament. Ces complications motrices et non-motrices des thérapies dopaminergiques, font intervenir une dysfonction du réseau des ganglions de la base. Ce travail a exploré le lien entre l’accumulation de la protéine ΔFosB et les modifications des propriétés électriques des neurones impliqués dans l’expression des dyskinésies, en utilisant une technique d’inactivation sélective des neurones exprimant ΔFosB dans le striatum de rat et de singe. Mes travaux ont également évalué chez le singe, comment la L-Dopa modifiait les taux de monoamines pour engendrer les dyskinésies. Ceci m’a permis de montrer que les structures cognitives et limbiques sont elles aussi affectées et qu’elles pourraient être directement impliqués dans les dyskinésies. Sur cette base, j’ai étudié la physiopathologie des troubles du traitement de la récompense et démontré que la L-Dopa, le traitement de référence de la MP, peut acquérir des propriétés récompensantes proches de celles de la cocaïne dans un modèle rat de la MP par surexpression de gène codant pour l’α-synucléine mutée. J’ai également utilisé des procédures d’auto-administration intraveineuse chez le rat pour montrer que le Pramipexole, un agoniste dopaminergique couramment utilisé dans le traitement de la MP, possédait des propriétés renforçantes. Ceci m’a permis de souligner que des susceptibilités individuelles sous-tendraient le développement de ces addictions comportementales. Ces découvertes ont ensuite été complétées par des expériences montrant que les altérations liées à la MP modifiaient le trait d’impulsivité des rats et que les traitements dopaminergiques pouvaient empirer ces changements. / My PhD focused on the alterations of the dopaminergic response in Parkinson’s disease (PD). Motor impairments in PD are reduced by the dopamine precursor L-Dopa and/or dopamine agonists. However, these medications elicit motor (dyskinesia) and non-motor side-effects. Up to 15% of PD patients under dopamine agonists experience behavioral addictions and withdrawal syndrome, and 3-4% of patients treated with L-Dopa or apomorphine exhibit compulsive medication intake. Both motor and non-motor complications of dopaminergic therapies involve dysfunctions in the basal ganglia network. I explored the link between deltaFosB protein accumulation and the cellular electrical properties that trigger dyskinesia by using a cell-type specific inactivation of FosB expressing neurons of the striatum in rats and monkeys. I have also investigated in monkeys how L-Dopa modifies monoaminergic functions to mediate dyskinesia and demonstrated that limbic/cognitive structures are identically affected providing a basis for a non-motor component involved in motor side effects in PD. From this, I studied the pathophysiology of addiction-like disorders by revealing that L-Dopa, the most widely-used treatment for PD, can acquire rewarding properties similar to cocaine in a viral-mediated rat model of PD. I also used self-administration procedures in rats to demonstrate the rewarding properties of Pramipexole, a dopamine agonist commonly use in the treatment of PD, and identified individual susceptibilities in the development of addiction-like disorders. These findings were followed by additional work showing that PD alterations modify the impulsivity trait of rats and that medication might worsen these changes.

ContexteAu cours de la maladie de Parkinson, les agonistes dopaminergiques sont associés à la survenue de troubles du contrôle des impulsions (TCI). Leur physiopathologie est supposée liée à une dérégulation du circuit dopaminergique méso-limbique, impliqué dans l’intégration des conséquences d’une action afin d’adapter les comportements ultérieurs. Les agonistes dopaminergiques, par la stimulation tonique qu’ils entrainent, conduiraient à une surestimation des conséquences positives des actions antérieures et la poursuite de comportements aux conséquences néfastes.Nous avons exploré (i) la connectivité fonctionnelle striato-corticale en IRM fonctionnelle de repos, (ii) des marqueurs électro-encéphalographiques (EEG) d’intégration du feedback au cours d’une tache de pari : feedback-related negativity (FRN), feedback-related positivity (FRP) et oscillations dans la bande de fréquence thêta (4-7 Hz) chez 20 patients parkinsoniens avec TCI actif, 19 patients parkinsoniens sans TCI et 19 contrôles sains.IRM fonctionnelle : Le striatum ventral, le noyau caudé dorsal, le putamen antérieur et postérieur étaient segmentés semi-automatiquement. Pour chaque région d’intérêt, une analyse de connectivité fonctionnelle était réalisée sur les données d’IRM fonctionnelle projetées sur la surface corticale.Approche neurophysiologique : les sujets réalisaient une tâche composée de paris répétés, couplée à un enregistrement EEG. Le signal EEG était moyenné pour chaque condition et pour chaque sujet. L’amplitude de la FRP était mesurée en Cz et l’amplitude de la FRN en Fz sur la courbe de différence entre les potentiels évoqués par les pertes et les potentiels évoqués par les gains. Les spectres de puissance ont été calculés en utilisant une transformation en ondelettes sinusoïdales de Morlet et moyennés par condition. La puissance maximale du signal, dans la bande de fréquence thêta, entre 200 et 500 millisecondes après l’affichage du feedback était mesurée.Analyse de la connectivité striato-corticale : Chez les patients parkinsoniens, l’existence d’un TCI était associée à une déconnexion fonctionnelle entre le putamen antérieur gauche et les gyrus cingulaire antérieur et temporal inférieur gauche. Il existait chez ces patients une tendance à une déconnexion fonctionnelle entre (i) le putamen antérieur gauche et le gyrus frontal inférieur, (ii) le putamen postérieur et les gyrus temporal inférieur, frontal supérieur, cingulaire postérieur et frontal médial à gauche, ainsi que les gyrus frontal médial, cingulaire et frontal moyen à droite, (iii), le noyau caudé dorsal et le gyrus rectus, le gyrus frontal moyen et le gyrus temporal inférieur à gauche.Potentiels évoqués : Chez les patients parkinsoniens sans TCI et chez les contrôles, mais pas chez les patients parkinsoniens avec TCI, la FRP était plus ample après les gains qu’après les pertes suite à un choix peu risqué.Analyse temps-fréquence : En Cz, les gains étaient associés à une augmentation plus importante de la puissance thêta que les pertes chez les patients parkinsoniens sans TCI et chez les contrôles, mais pas chez les patients parkinsoniens avec TCI. Il existait une augmentation de la puissance thêta après un résultat ample inattendu (boost), en Fz chez les contrôles et en FCz chez les parkinsoniens avec TCI, mais pas chez les patients parkinsoniens sans TCI.Il existe chez les patients parkinsoniens ayant un TCI une altération de marqueurs EEG d’intégration de la récompense compatible avec une moins bonne discrimination des gains et des pertes et une plus grande sensibilité aux résultats amples, inattendus (boost), supposés entrainer une activation importante des voies dopaminergiques méso-limbiques. Il semble donc bien exister, chez les patients ayant un TCI une dysfonction des mécanismes d’intégration du feedback. Cette dysfonction s’associe, au repos, à une altération de la connectivité striato-corticale qui va au-delà du seul système limbique. / BackgroundIn Parkinson’s disease, dopamine agonists are associated with an increased risk of impulse control disorders (ICD). Their occurrence is supposed to be related with a deregulation of the dopaminergic meso-limbic pathway, involved in the processing of the consequences of previous action to adapt future behaviors. Dopamine agonists, through a tonic stimulation of the dopamine receptors would lead to an overestimation of the positive consequences of actions, and therefore, continuation of a harmful behavior.Method:We investigated (i) the resting-state striato-cortical functional connectivity using functional MRI, and (ii) electro-encephalographic (EEG) markers of feedback processing during a gambling task : the feedback related negativity (FRN), the feedback related positivity, (FRP), and the theta band oscillations (4-7 Hz) in 20 Parkinson’s disease patients with an active ICD, 19 Parkinson’s disease patients without ICD, and 19 healthy subjects.Functional MRI: The ventral striatum, dorsal caudate, and anterior and posterior putamen were semi-automatically segmented. For each region of interest, a seed-based connectivity analysis was performed on preprocessed fMRI data mapped on the ipsilateral cortical surface.Neurophysiological approach: The subjects underwent an EEG while performing a gambling task. The EEG was averaged for each condition and each subject. The FRP amplitude was measured in Cz, and the FRN amplitude was measured in Fz on the difference wave between the potential evoked by losses and by gains. The power spectra were computed by using a sinusoidal Morlet wavelet transform and averaged by condition. The maximum power in the theta frequency band was computed for each participant and each condition.Results:Cortico-striatal connectivity analysis: The presence of an ICD in patients with PD was associated with functional disconnection between the left anterior putamen and both the left inferior temporal and anterior cingulate gyrus. ICD patients also displayed a trend toward a functional disconnection between (i) the left anterior putamen and the inferior frontal gyrus, (ii) the posterior putamen and the inferior temporal gyrus, superior frontal gyrus, posterior cingulate, and medial frontal gyrus on the left, as well as the medial frontal gyrus, middle frontal gyrus, and cingulate gyrus on the right, (iii) the dorsal caudate and the gyrus rectus and orbitofrontal cortex, and the middle frontal and inferior temporal gyrus on the left.Evoked potentials: In Parkinson’s disease patients without ICD and healthy controls, the FRP was greater after gains that after losses following a non-risky choice. There was no difference in FRP amplitude after losses and gains in Parkinson’s disease patients with ICD.Time-frequency analysis: At Cz, positive outcomes (gains) were associated with greater theta power than negative outcomes (losses) in Parkinson’s disease patients without ICD and in healthy controls, but not in Parkinson’s disease patients with ICD. There was an increase in theta power after unexpectedly high outcomes, at Fz in healthy controls and in FCz in Parkinson’s disease patients with ICD, whereas theta power was not modulated by the magnitude of the outcome in PD patients without ICDs.Conclusions:Parkinson’s disease patients with ICD have an alteration in EEG markers of reward in line with an altered discrimination of gains and losses and a greater sensitivity to unexpectedly high outcomes, supposed to lead to a significant activation in the dopaminergic meso-limbic pathways. These findings are in line with a dysfunction in reward processing in ICD in Parkinson’s disease. This dysfunction is associated, at rest, with an alteration in striato-cortical connectivity that goes beyond a pure dopaminergic meso-limbic dysfunction.

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