Les pathologies du motoneurone sont caractérisées par une atteinte progressive des motoneurones au niveau de la corne antérieur de la moelle épinière. Au delà de cette susceptibilité anatomique commune, qui est responsable d’une atteinte motrice progressive et diffuse dans ces pathologies, d’autres systèmes neurologiques sont touchés. La dégénérescence du faisceau corticospinal est une caractéristique classique dans la sclérose latérale amyotrophique, qui est la maladie du motoneurone la plus commune chez l’adulte. Cependant, il est de plus en plus reconnu que la SLA est une maladie multisystémique. En particulier, une atteinte précoce du système sensoriel a été démontrée dans la modèle animal de la SLA ainsi que dans l’amyotrophie spinal liée à la mutation du gène SMN1 (survival motor neuron 1 en anglais). Chez les patients, l’imagerie par résonance magnétique (IRM) a émergé comme l’approche la plus performant à l’étage cérébral, permettant d’extraire des indices quantitatifs sur la perte neuronale, la dégénérescence axonale et la démyélinisation dans les pathologies neurodégénératives. Cependant, l’investigation de l’étage médullaire dans ces pathologies est difficile à mener à cause des nombreux défis techniques et méthodologiques que représente l’IRM de la moelle épinière.L’objectif de ce projet de thèse a été d’utiliser l’approche IRM multiparamétrique au niveau de la moelle épinière pour analyser les structures de la matière grise et blanche qui sont atteintes dans deux des pathologies du motoneurone les plus répondues, c’est-à-dire la SLA et la SMA, leurs altérations au cours du temps et leurs corrélations fonctionnelles avec les données cliniques et électrophysiologiques. / Degenerative motor neuron diseases (MND) are characterized by a progressive dysfunction and loss of ventral horn motor neurons of the spinal grey matter. Beyond this common anatomical susceptibility, which is responsible for a progressive and diffuse weakness, other neurological systems are also impaired. The corticospinal tract (CST) degeneration is a classical feature of amyotrophic lateral sclerosis (ALS), which is the most common adult onset motor neuron disease, but a more widespread multisystem involvement is now well recognized. In particular, early sensory system involvement has been demonstrated in animal models of ALS and also of survival motor neuron 1 gene linked spinal muscular atrophy (SMN1-linked SMA). In human patients, magnetic resonance imaging (MRI) has emerged as the most powerful approach at the brain level to extract quantitative data on neuronal loss, axonal degeneration and demyelination in degenerative conditions. Studies at the spinal cord levels are scarce mainly because of technical and methodological difficulties. The objective of the present thesis project was to use a multi-parametric MRI approach at the spinal cord level to analyze grey and white matter structures that are impaired in two most common MND, i.e. ALS and SMN1-linked SMA, their temporal alterations during the disease course and the functional correlates, as assessed by clinical and electrophysiological examinations.

Spinal muscular atrophy (SMA) is the leading genetic cause of death of young children. It is an autosomal recessive disease caused by the mutation and/or the deletion within the ubiquitously expressed survival motor neuron 1 (SMN1) gene. SMA pathology is characterized by spinal cord motor neuron degeneration, neuromuscular junction (NMJ) defects and muscular atrophy. Upon disease onset, SMA patients progressively become paralyzed and in the most severe cases, they die due to respiratory complications. Over the years, it has become clear that SMN is a multi-functional protein with important roles in small nuclear ribonucleoprotein (snRNP) assembly, RNA metabolism, axonal outgrowth and pathfinding, mRNA transport as well as in the functional development of NMJs, skeletal muscle and cardiac muscle. However, it remains unclear which of these functions, and the respective perturbed molecular pathways, dictate SMA pathogenesis. Here, we have established Smn-depleted PC12 cells and an intermediate SMA mouse model to characterize a role for Smn in the regulation of actin cytoskeleton dynamics. We find that Smn depletion results in the increased expression of profilin IIa and active RhoA (RhoA-GTP) as well as the decreased expression of plastin 3 and Cdc42. Importantly, the inhibition of rho-kinase (ROCK), a direct downstream regulator of RhoA, significantly increased the lifespan of SMA mice and shows beneficial potential as a therapeutic strategy for SMA. In an addition, we have uncovered a muscle- and motor neuron-independent role for SMN in the regulation of pancreatic development and glucose metabolism in SMA mice and type 1 SMA patients. This finding highlights the importance of combining a glucose tolerance assessment of SMA patients with their existing clinical care management. Thus, our work has uncovered two novel and equally important roles for the SMN protein, both of which contribute significantly to SMA pathogenesis.

Les amyotrophies spinales infantiles (ASI) de type 1 (subdivisées en type 1 vrai et 1 bis), sont des maladies neuromusculaires qui paralysent progressivement l’enfant, mettant en jeu son pronostic vital lors de l’atteinte des muscles respiratoires. L’assistance respiratoire invasive par trachéotomie évite son décès, mais soulève un questionnement éthique compte-tenu de la gravité du handicap moteur. L’ASI de type 1 vrai représente la forme la plus grave. Ces enfants étant totalement paralysés et pouvant très difficilement communiquer, ils ne sont pas trachéotomisés et décèdent dans la petite enfance. Le type 1 bis étant un peu moins sévère avec possibilité pour l'enfant de s'exprimer, les équipes médicales françaises se positionnent généralement en faveur de la trachéotomie, ce qui ne fait pas l’unanimité au niveau international. Cette question soulève donc un questionnement éthique, car lorsque les professionnels évaluent la vie qu’elle va imposer à l’enfant ainsi qu’à sa famille, ils redoutent éventuellement qu’elle représente une obstination déraisonnable de soins. Mais qu’ils y soient favorables ou au contraire défavorables, ils ne peuvent décider seuls de la démarche à entreprendre et il leur est impossible d’exclure les parents du processus décisionnel. Au regard de ces problématiques, ce travail porte une attention particulière aux parents de ces enfants avec 2 thématiques de recherche approchées par des études qualitatives : L’une sur leur vécu de la prise de décision de recourir ou non à la trachéotomie, avec la réalisation de deux études phénoménologiques : une auprès de parents dont l’enfant est décédé sans trachéotomie, l’autre auprès de parents ayant un enfant vivant avec une trachéotomie. L’autre sur les conséquences de la trachéotomie pour l’enfant et sa famille, menée auprès de mamans d’enfants trachéotomisés. Les résultats de ces travaux mettent en exergue les difficultés d’être exposé à une telle prise de décision en tant que parent, et le cheminement ainsi que les évènements qui les mènent à un moment ou un autre à se positionner sur la question. Ils interrogent également la place dans la société de l’enfant tétraplégique, trachéotomisé et ventilo-dépendant. Son état représente un paroxystique degré de vulnérabilité physique et sociale, considérablement majoré par le fait qu’il ne peut pas, comme l’adulte, tenter de prendre sa vie en main. Ce sujet n’étant jamais évoqué dans la presse non spécialisée, ces situations restent souvent dans l’ombre alors qu’elles représentent des vies qui ont grandement besoin de tolérance et de solidarités humaines (individuelles et collectives) pour ne pas s’éteindre. Ces dernières déterminent en partie le devenir de l’enfant et favorisent ou au contraire, empêchent la création de sa place légitime au sein de la société / Childhood spinal muscular atrophy (SMA) type 1 (divided into true type 1 and 1a), are progressively paralyzing neuromuscular diseases that afflict children, affecting their prognosis when respiratory muscles are involved. Invasive ventilatory support by tracheotomy prevents death, but raises ethical issues in view of the severity of motor impairment. SMA type 1 represents the most severe form. These children are completely paralyzed and communicate only with great difficulty; they are not tracheotomized and die in infancy. For Type 1a, being somewhat less severe with the possibility for children to express themselves, French medical teams are generally positioned in favor of tracheotomy, which is not an internationally unanimous approach. This question raises an ethical issue because when professionals assess the life that will result for the child and family, they sometimes fear that it represents unreasonable and excessive care. Whether their views are favorable or unfavorable regarding ventilatory support, they cannot decide alone which approach should be undertaken; it is impossible to exclude parents from decision making. Given these issues, this study pays particular attention to parents of children with two research themes through qualitative research : One focus was on parents’ experience of deciding whether or not to accept tracheotomy, which was examined through two phenomenological studies: one with parents whose child died without a tracheotomy, the other with parents with children living with a tracheotomy. The other focus was on the consequences of a tracheotomy for the child and family, conducted among mothers of children with tracheotomies. The results of these studies highlight the difficulties of being faced with such a decision as a parent, and the journey and events that lead to one point or another on this issue. They also question the place in society of the quadriplegic child with a tracheotomy and ventilator dependence. The child’s condition represents a paroxysmal degree of physical and social vulnerability, significantly increased by the fact that he/she cannot, as adults, take his/her life in hand. This subject is never mentioned in the lay press; these situations often remain in the shadows while there are lives that are in dire need of tolerance and human solidarity (individual and collective) to not be extinguished. This partly determines the future of the child and promotes or, on the contrary, prevents the creation of his/her rightful place in society.

No description available.

A Amiotrofia Espinhal Progressiva (AEP) é uma doença autossômica recessiva que afeta os motoneurônios do corno anterior da medula espinhal, acarretando hipotonia e fraqueza muscular. A partir do conhecimento do mecanismo molecular da AEP, abriu-se um campo para testes clínicos com agentes farmacológicos que possam aumentar o nível da proteína SMN2. Diversas drogas com esta ação estão sendo testadas na tentativa de encontrar um possível tratamento para esta trágica doença. O ácido valpróico (AV), droga muito utilizada para o tratamento da epilepsia mostrou ter a propriedade de ativar o promotor do gene da proteína SMN2, aumentando a sua produção. Tendo em vista que não há uniformização do sistema de avaliação clínica dos resultados do tratamento em diferentes países, foi elaborado um protocolo selecionando métodos de avaliação fáceis, rápidos e já validados a fim de verificar se o AV é eficaz para manter ou melhorar a força muscular dos pacientes com AEP. Os métodos selecionados foram: escala Medical Research Council (MRC) para força muscular; Hammersmith motor ability score para habilidade motora; goniometria das principais articulações; cronometragem de tempo despendido para deambular, quando possível; índice de Barthel para atividades da vida diária e, por fim, um questionário para verificar as modalidades de fisioterapia e hidroterapia em uso. Vinte e dois pacientes com AEP tipo II e III, com idades variando de 2 a 18 anos, medicados com AV, foram avaliados a cada três meses durante um ano, totalizando cinco visitas, das quais a primeira ocorreu nos dias anteriores ao início do tratamento. Os resultados dos testes demonstraram que, durante o seguimento de um ano, os pacientes obtiveram melhora na habilidade motora, porém não na força muscular, o que é um resultado extremamente positivo. Crianças com idade menor ou igual a 6 anos mostraram melhores ganhos quanto à habilidade motora. / Spinal Muscular Atrophy (SMA) is an autosomal recessive disorder that affects the spinal motoneurons, resulting in hypotonia and muscle weakness. The knowledge of the molecular mechanism of SMA has originated new researches including clinical trials with pharmacological agents that increase SMN2 protein level. Many drugs with this action are being tested with the aim of finding a possible treatment for this severe disease. The valproic acid (VA), a well-known drug used to treat epilepsy has the property of activating the SMN2 gene promoter and then to increase SMN2 protein level. Since there isnt an uniform system for the clinical evaluation of the treatment results, we selected a set of easy, fast and already validated methods to evaluate if the VA is effective to stabilize or improve the motor function in patients with SMA. The selected methods were: Medical Research Council scale (MRC) to muscular strength; Hammersmith motor ability score to motor ability; goniometry of the main joints; time to walk when possible; Barthel índex for daily activities, and a questionnaire to verify the types of physiotherapy and hydrotherapy in use. Twenty two patients with SMA II and III, aged between 2 and 19 years, and treated with VA were evaluated every three months during the period of one year; the first evaluation occurred immediately before the onset of the treatment. The results of the tests demonstrated that along the period of 12 months the patients didnt gain muscle strength but improved their motor ability, that can be considered a positive result. Children aged six years or younger had a higher gain in motor ability along the period of the study.

Les techniques de criblage actuelles (in vitro et in silico) sont dépendantes des efforts menés en biologie médicinale pour identifier des cibles biologiques pertinentes ; cibles difficiles à définir pour les maladies génétiques dites "perte de fonction". De plus, les composés issus de ces cribles s'avèrent souvent inefficaces et/ou toxiques une fois confrontés à la complexité physiologique d'un organisme entier. Pour contourner ce problème, nous proposons d'utiliser le nématode C. elegans, notamment pour des maladies répondant aux critères suivants : i) physiopathologie complexe et/ou mal comprise excluant le développement à court terme de médicaments sur une base rationnelle, ii) peu d'espoir de thérapie génique/cellulaire à court terme, iii) conservation chez C. elegans du gène relié à la maladie humaine et induisant un phénotype exploitable une fois inactivé. Nous démontrons ici que ce petit nématode permet de tester, à moindre coût, un grand nombre de composés chimiques tout en conservant la complexité physiologique d'un animal entier. De plus, la souplesse génétique de cet animal permet d'apporter rapidement des informations sur le mode d'action des composés identifiés. Ainsi, en plus du but initial visant à identifier des molécules bioactives à intérêt thérapeutique, cette approche peut permettre de dégager de nouvelles cibles moléculaires utiles pour l'industrie chimique, et cruciales pour la recherche de traitements contre les maladies perte de fonction. Finalement, nous présentons comment mettre en place une telle stratégie, notamment pour la myopathie de Duchenne, l'amyotrophie spinale et le syndrome de Schwartz-Jampel. Enfin, nous présentons les résultats obtenus lors des différentes campagnes de criblage, les validations des molécules les plus prometteuses et les travaux effectués pour tenter de comprendre leur mode d'action chez le nématode.

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on March 10, 2010). Vita. Thesis advisor: Lorson, Christian L. "December 2008" Includes bibliographical references

The scope of this dissertation focuses on issues related to the quality of life of children suffering with spinal muscular atrophy (SMA) and their carers and the associated social impact on families affected by this progressive and incurable disease. It describes ethical aspects of help to families with SMA and serious decisions in relation to the need to connect to artificial ventilation. Spinal Muscular Atrophy - SMA is a motoneuron disease i.e. disease of neurons, which are responsible for conscious movements of muscles e.g. running, head movement and swallowing. The prevalence is approximately 1 newborn for 6000 live births and approximately 1 person of 40 people is the carrier of the disease. SMA affects all the bone muscles i.e. proximal muscles are often affected the most. Everyone affected is in some point in life, depending on stage and type, reliant on mechanical or electrical wheelchair, in many cases also on artificial ventilation and permanent 24hr care. Families affected by this illness accept the fact of this progressive and incurable illness differently, this dissertation reflects upon such different perceptions on quality of life of the affected children, the carers. It forms a contribution in building a foundation for organising multi-discipline teams of experts with sole purpose of therapeutical interventions, to support the child and his/hers family. The World Health Organization (WHO) defines palliative care as "improving quality of life of patients facing life-threatening illnesses, and their families, through the prevention and relief of suffering by early identification and treatment of pain and other problems, whether physical, psychological, social or spiritual." Palliative care prepares families for these situations and should be provided along with whatever treatment options families choose. This dissertation is a comprehensive information base to support children affected by SMA and their families in early care in Czech Republic and in the process of inclusive educational integration into mainstream society.

A Amiotrofia Espinhal Progressiva (AEP) é uma doença autossômica recessiva que afeta os motoneurônios do corno anterior da medula espinhal, acarretando hipotonia e fraqueza muscular. A partir do conhecimento do mecanismo molecular da AEP, abriu-se um campo para testes clínicos com agentes farmacológicos que possam aumentar o nível da proteína SMN2. Diversas drogas com esta ação estão sendo testadas na tentativa de encontrar um possível tratamento para esta trágica doença. O ácido valpróico (AV), droga muito utilizada para o tratamento da epilepsia mostrou ter a propriedade de ativar o promotor do gene da proteína SMN2, aumentando a sua produção. Tendo em vista que não há uniformização do sistema de avaliação clínica dos resultados do tratamento em diferentes países, foi elaborado um protocolo selecionando métodos de avaliação fáceis, rápidos e já validados a fim de verificar se o AV é eficaz para manter ou melhorar a força muscular dos pacientes com AEP. Os métodos selecionados foram: escala Medical Research Council (MRC) para força muscular; Hammersmith motor ability score para habilidade motora; goniometria das principais articulações; cronometragem de tempo despendido para deambular, quando possível; índice de Barthel para atividades da vida diária e, por fim, um questionário para verificar as modalidades de fisioterapia e hidroterapia em uso. Vinte e dois pacientes com AEP tipo II e III, com idades variando de 2 a 18 anos, medicados com AV, foram avaliados a cada três meses durante um ano, totalizando cinco visitas, das quais a primeira ocorreu nos dias anteriores ao início do tratamento. Os resultados dos testes demonstraram que, durante o seguimento de um ano, os pacientes obtiveram melhora na habilidade motora, porém não na força muscular, o que é um resultado extremamente positivo. Crianças com idade menor ou igual a 6 anos mostraram melhores ganhos quanto à habilidade motora. / Spinal Muscular Atrophy (SMA) is an autosomal recessive disorder that affects the spinal motoneurons, resulting in hypotonia and muscle weakness. The knowledge of the molecular mechanism of SMA has originated new researches including clinical trials with pharmacological agents that increase SMN2 protein level. Many drugs with this action are being tested with the aim of finding a possible treatment for this severe disease. The valproic acid (VA), a well-known drug used to treat epilepsy has the property of activating the SMN2 gene promoter and then to increase SMN2 protein level. Since there isnt an uniform system for the clinical evaluation of the treatment results, we selected a set of easy, fast and already validated methods to evaluate if the VA is effective to stabilize or improve the motor function in patients with SMA. The selected methods were: Medical Research Council scale (MRC) to muscular strength; Hammersmith motor ability score to motor ability; goniometry of the main joints; time to walk when possible; Barthel índex for daily activities, and a questionnaire to verify the types of physiotherapy and hydrotherapy in use. Twenty two patients with SMA II and III, aged between 2 and 19 years, and treated with VA were evaluated every three months during the period of one year; the first evaluation occurred immediately before the onset of the treatment. The results of the tests demonstrated that along the period of 12 months the patients didnt gain muscle strength but improved their motor ability, that can be considered a positive result. Children aged six years or younger had a higher gain in motor ability along the period of the study.

Barn med Spinal muskelatrofi lever ett liv med begränsad rörlighet. Deras vardag innehåller att mycket träning med syfte att kunna leva ett bättre liv. I vår digitala värld finns det idag många digitala spel som syftar till träning, exempelvis Nintendo Wii-spel och det populära spelet Just Dance. Utan att vi tänker på det, tränar vi kroppen medan vi utför spelets olika moment. Men hur kan barn bibehålla motivation och hur kan immersion uppstå för att barn ska glömma rum och tid när dem tränar? Vi har i vår studie samarbetat med företaget Nordic Forest Games, som på uppdrag av ett läkemedelsföretag, utvecklar ett mobilspel för barn med Spinal muskelatrofi. Vi har undersökt vilka egenskaper ett digitalt spel bör ha för att inte upplevs som enbart träning. I studien deltar två fysioteraputer och fyra föräldrar med syfte att beskriva sina upplevelser kring deras barns vardag och hur träning och motivation upplevs. Vid analys av data har teorin Hedonic Motivation System Adoption Model (HMSAM) tillämpats för att kunna ringa in vilka olika områden som är central hos barnen för att uppleva immersion och motivation. Resultatet i studien är inte generaliserbart på grund av dels det låga antalet deltagare i studien och dels med tanke på att Spinal muskelatrofi är en ovanlig sjukdom av stor variation och mycket individuell. Utan att kunna dra någon generell slutsats har vi kunnat urskilja delar som är intressanta att studera vidare när det gäller tävlingsmoment och inkludering. Av företaget fick vi även tillgång till en prototyp av spelet. För att utvärdera prototypen gjordes en heuristisk utvärdering i enlighet med att finna användbarhetsproblem genom att se på prototypen genom Nielsens tio heuristiska riktlinjer. Med dessa två kvalitativa metoder har studien antagit en kvalitativ ansats där resultaten sedan kopplats samman med teorin HMSAM. / Children with spinal muscular atrophy live a life of limited mobility. Their everyday life includes a lot of exercise with the goal of being able to live a better life. In our digital world today, there are many digital games aimed at training, such as Nintendo Wii games and the popular game Just Dance. Without thinking about it, we train the body while performing the various steps of the game. But how can children maintain motivation and how can immersion occur for children to forget space and time when they exercise? In our study, we collaborated with the company Nordic Forest Games, which on behalf of a pharmaceutical company, develops a mobile game for children with spinal muscular atrophy. We have investigated what qualities a digital game should have in order not to be perceived as just training. Two physiotherapists and four parents participate in the study with the aim of describing their experiences of their children's everyday life and how exercise and motivation are experienced. When analyzing data, the Hedonic Motivation System Adoption Model (HMSAM) theory has been applied in order to be able to delineate which different areas are central to children in order to experience immersion and motivation. The result of the study is not generalizable due partly to the low number of participants in the study and partly given that Spinal muscular atrophy is an unusual disease of great variety and very individual. Without being able to draw any general conclusions, we have been able to distinguish parts that are interesting to study further in terms of competition elements and inclusion. The company also gave us access to a prototype of the game. To evaluate the prototype, an heuristic evaluation was made in accordance with finding usability problems by looking at the prototype through Nielsen's ten heuristic guidelines. With these two qualitative methods, the study has adopted a qualitative approach where the results are then linked to the theory HMSAM.