Made available in DSpace on 2016-04-27T18:47:30Z (GMT). No. of bitstreams: 1 Ana Lucia Marques de Souza Novo.pdf: 654891 bytes, checksum: d755981e503a95db31acb0b11f7f9d00 (MD5) Previous issue date: 2008-09-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study intends to understand how features related to elderly dementia care develop, if grounded on a Homely Gerontology Management (Gestão Gerontológica Domiciliar - GGD). Professional experience incited me to write this study on GGD s building process, within elderly dementia care organization, involving also the family, caregivers and the environment. Research was carried through in the field of private homely care, in São Paulo, along with a team of professionals responsible for the care of an elderly patient with dementia. In a qualitative approach, I employed the participant observation of the care organization, as well as a semi-structured interview with some of the team s members. The study shows that the care organization to dementia subjects yields dynamic features and demands to be constantly re-structured. GGD is part of this complex functioning group and, in this study, seven approaches are described and detailed: 1) clinic evolution s monitoring; 2) the patient s emotional and psychic suffering aspects care; 3) family orientation; 4) recruiting, selection, training and development of professionals involved in elderly care; 5) orientation and management of home employees; 6) environmental adequacy; 7) financial management. The obtained knowledge does not intend to cover all the questions in the field. However, it was presented as a possible therapeutic in care actions carried out in the private health system, and which, therefore, forces us to reflect upon the extension of such experience to the public sphere, in lack of care projects to elderly subjects in fragile situation / O estudo pretende compreender como se desenvolvem os aspectos que abrangem o cuidado no atendimento a idosos com demência, quando parte de um programa de Gestão Gerontológica Domiciliar (GGD). A experiência profissional incitou-me a escrever este estudo sobre o processo de construção da GGD, na organização do cuidado a idosos com demência, familiares, cuidadores envolvidos e o ambiente. A pesquisa foi feita no campo da assistência domiciliar privada, na cidade de São Paulo, com uma equipe de profissionais envolvidos no cuidado a uma idosa com demência. Em abordagem qualitativa, utilizei a observação participante da organização do cuidado e entrevista semi-estruturada com alguns membros da equipe. O estudo constatou que a organização do cuidado nas situações demenciais tem caráter dinâmico e requer constante reestruturação. A GGD faz parte desse grupo de atuação complexa e, nesta pesquisa, estão descritas e detalhadas sete frentes: 1) acompanhamento da evolução clínica; 2) cuidados com os aspectos emocionais e o sofrimento psíquico do paciente; 3) orientação familiar; 4) recrutamento, seleção, treinamento e desenvolvimento dos profissionais envolvidos no atendimento ao idoso; 5) orientação e administração de funcionários domésticos; 6) adequação ambiental; 7) administração financeira. O conhecimento adquirido não pretende ser proposta que abrange a totalidade dos fatores desse cenário. No entanto, apresentou-se como terapêutica possível nas ações de cuidado que ocorrem no sistema privado, e que, consequentemente, nos leva a refletir sobre a extensão da experiência à esfera pública, que tem carência de planos de atendimento aos idosos em situação de fragilidade

[pt] A partir do crescente interesse no estudo da fase pré-clínica das demências possibilitando a identificação clínica precoce do processo de adoecimento, o estudo mais aprofundado do Comprometimento Cognitivo Leve (CCL) torna-se de grande importância. Ele corresponde a uma provável transição para demência e seu diagnóstico pode promover intervenção precoce tanto medicamentosa quanto comportamental. A presente dissertação tem como objetivo investigar as principais questões metodológicas associadas ao uso das medidas neuropsicológicas para definir critérios diagnósticos de CCL, comparando instrumentos cognitivos (Bateria Breve de Rastreio Cognitivo e Escala Mattis de Avaliação de Demência) em uma amostra de idosos assistidos em um ambulatório de geriatria de hospital público do Rio de Janeiro. / [en] The growing interest of preclinical phase of dementia study allow early clinical identification of the disease process, the depth study of Mild Cognitive Impairment (MCI) becomes of great importance. It corresponds to a likely transition to dementia and its diagnosis can promote early both drug and behavior intervention. The present dissertation aims to investigate the main methodological issues associated with the use of neuropsychological measures to establish diagnostics criteria for MCI comparing cognitive instruments (Brief Cognitive Screening Battery and Mattis Dementia Rating Scale) in an elderly sample assisted in a geriatric outpatient clinic of a public hospital in Rio de Janeiro.

[pt] O presente estudo teve como objetivos determinar os melhores preditores neuropsicológicos de demência e analisar a trajetória cognitiva de idosos com comprometimento cognitivo leve (CCL) em dois anos. Oitenta e sete idosos com CCL foram submetidos a uma bateria de testes neuropsicológicos e 62 foram reavaliados após dois anos. 21,8 por cento converteram para demência. Os resultados revelaram que a memória episódica e a memória de trabalho foram os melhores preditores de conversão de CCL para demência após dois anos e que idosos com declínio em duas ou mais funções cognitivas apresentaram maior prejuízo na funcionalidade e maior porcentagem de conversão para demência que os idosos com declínio apenas nas funções executivas. Além disso, os resultados mostraram que os sintomas de depressão estão mais associados ao perfil de idosos que declinam somente nas funções executivas. / [en] This study aimed to determine the best neuropsychological predictors of dementia and analyze the cognitive trajectory of older adults with mild cognitive impairment (MCI) in a two-year follow-up study. 87 older adults with MCI were submitted to a broad neuropsychological battery and 62 were evaluated two years later. 21.8 percent converted to dementia. The results revealed that episodic memory and working memory are the best predictors of dementia from MCI after two years. Older adults showing decline in two or more cognitive functions showed greater deficits in functionality and higher percentages of conversion to dementia when compared to older adult with executive function decline. In addition, the results showed that depressive symptoms are specifically associated with older adults showing exclusively executive function decline.

[pt] A falta de consciência da doença, também denominada anosognosia, é um sintoma comum da Doença de Alzheimer (DA). Sua estrutura funcional e seus mecanismos subjacentes, contudo, não são inteiramente compreendidos. O nível de consciência possui grande relevância para o sucesso do tratamento e para o fardo do cuidador. Outro fator de considerável impacto nas relações interpessoais e, portanto, no bem-estar dos pacientes e cuidadores, é o processamento emocional. A presente tese explora esses tópicos através de quatro artigos. No Artigo 1, utiliza-se a modelagem de equações estruturais (SEM, do inglês structural equation modeling) em uma grande amostra de pessoas com DA para investigar a natureza da relação entre função cognitiva, estado de humor e funcionalidade na previsão do nível de consciência da condição. Os resultados demonstraram que uma menor funcionalidade cognitiva e um maior nível de estado depressivo de humor influenciaram negativamente a capacidade dos pacientes de realizar atividades da vida cotidiana, o que, por sua vez, se mostrou associada a uma maior consciência da doença. O Artigo 2 investigou as origens executivas e mnemônicas da anosognosia na DA, utilizando uma tarefa de tempo de reação e medindo a consciência a respeito da performance na tarefa. Os dados demonstraram que o monitoramento online dos pacientes estava preservado, enquanto o monitoramento a médio e longo prazo esteve comprometido. Tal achado foi corroborado por resultados de dados eletrofisiológicos. Dessa forma, os resultados fortalecem as evidências favoráveis a uma natureza mnemônica, e não executiva, da anosognosia na DA, o que se mostra de acordo com o Cognitive Awareness Model (CAM). O Artigo 3 investigou a reatividade emocional a imagens negativas, auto-relevantes e neutras utilizando medidas de excitação e valência, gravações de expressões faciais e dados eletrofisiológicos. A reatividade emocional dos pacientes de DA foi similar à de jovens adultos, mas as respostas eletrofisiológicas foram elevadas quando comparadas às de idosos saudáveis, o que pode ser explicado por uma falta de mecanismos de controle cognitivo. A apatia esteve associada a menores respostas eletrofisiológicas a figuras negativas, e a consciência de prejuízos sociais se relacionou com maiores níveis de excitação em imagens auto-relevantes. Por sua vez, o Artigo 4 discutiu como a DA afeta as habilidades emocionais através de uma revisão de literatura sobre a empatia desses pacientes. Os aspectos afetivos da empatia deste grupo clínico estiveram relativamente preservados, enquanto foram apresentados déficits nos componentes cognitivos. Os prejuízos relacionados aos componentes afetivos foram principalmente atribuídos a um declínio cognitivo geral. Nossos achados ressaltam que diferentes fatores influenciam a consciência da doença na DA, enfatizando o papel de sintomas neuropsiquiátricos, do funcionamento cognitivo e das atividades da vida diária. Além disso, processos executivos pareceram estar preservados, ao passo que dificuldades em atualizar e consolidar esse conhecimento podem ser uma possível causa de anosognosia na DA. Ademais, sugerimos que as habilidades emocionais são amplamente preservadas em pacientes de DA. Tais resultados são de grande importância para a prática clínica. Pesquisas translacionais são necessárias para implementar os achados de pesquisas em abordagens terapêuticas específicas. / [en] Lack of awareness of condition, also termed anosognosia, is a common symptom in Alzheimer s disease (AD). However, its functional structure and underlying mechanisms are not fully understood. Level of awareness has great relevance for treatment success and caregiver burden. Another factor that has considerable impact on interpersonal relationships and thus on well-being of patients and caregivers is emotional processing. The current thesis explores these topics through four articles. In Article 1, structural equation modeling (SEM) was used in a large sample of people with AD (PwAD) to investigate the nature of the relationship between cognitive function, mood state, and functionality in predicting awareness. Results showed that lower cognitive function and higher level of depressive mood state negatively influenced PwAD s ability to perform daily living activities, which in turn were associated with better awareness. Article 2 investigated executive and mnemonic origins of anosognosia in AD, with a reaction time task being applied to examine awareness of task performance. The findings demonstrated that online monitoring was preserved, while medium- and long-term monitoring were impaired. This was supported by results from electrophysiological data. The results strengthen the evidence for a mnemonic rather than executive nature of anosognosia in PwAD in accordance with the Cognitive Awareness Model (CAM). Article 3 investigated emotional reactivity to negative, self-relevant, and neutral pictures using ratings of arousal and valence, facial expression recordings and electrophysiological data. Emotional reactivity of PwAD was similar to young adults, but electrophysiological responses were elevated compared to healthy older adults, which might be explained by a lack of cognitive control mechanisms. Apathy was associated with reduced electrophysiological responses for negative pictures, and awareness of social impairments was linked to higher arousal ratings of self-relevant pictures. Article 4 discussed how higher emotional abilities are affected by AD, through a review of the literature on empathy in this clinical group. PwAD showed a pattern of relatively preserved affective aspects and impairments in cognitive components of empathy, whereby impairments in affective components can mainly be attributed to a general cognitive decline. Our findings highlight that different factors influence awareness in AD, emphasizing the role of neuropsychiatric symptoms (NPS), cognitive functioning and activities of daily living. Moreover, executive processes seem to be preserved, whereas impairments in updating and consolidation of this knowledge seem to be a possible cause for anosognosia in AD. Furthermore, we suggested that emotional abilities are largely preserved in PwAD. Our results have great significance for clinical practice. Translational research is needed to implement research findings into specific therapeutic approaches.

Notre travail s’inscrivant dans le cadre de la psychologie de la santé s’intéresse aux effets de l’annonce d’un diagnostic de trouble démentiel sur la qualité de vie de la personne âgée, au sein d’un service de consultation mémoire à Bourg-en-Bresse (France). Nous posons le postulat que la manière d’annoncer un diagnostic pourrait conditionner le vécu de la maladie. Notre étude traite des réactions des patients à la suite de cette annonce.Nous avons constitué plusieurs groupes de patients permettant d’étudier les effets de l’annonce selon différents critères : le niveau d’atteinte cognitive, le type d’attachement, le type d’annonce faite par le médecin, le temps de l’annonce. Ainsi, un groupe a été constitué de personnes âgées dites transversales (c’est-à-dire rencontré une fois au début, lors de leur annonce ou au cours de leur suivi médical), puis un autre groupe dit longitudinal (rencontré depuis leur annonce puis tous les 3 mois pendant presque 2 ans pour les suivis les plus longs) , et enfin un groupe contrôle , nous permettant de servir de référence afin de comprendre les réactions des patients. Afin de compléter nos données issues des précédents groupes, nous avons également rencontré les aidants de certaines personnes âgées impliquées dans le processus diagnostic afin d’étudier leur réaction face à l’annonce et enfin, avons rencontré 3 groupes de personnes gravitant autour de l’annonce (médecins généralistes, gériatres et un groupe de famille) afin d’étudier leur discours et représentations de l’annonce diagnostic.Les résultats nous montrent:- Au niveau statistique: seules les réactions des aidants sont significatives dans leur utilisation plus prononcée du coping actif : planification et dans l’utilisation de mécanisme défense mature.- D’un point de vue statistique descriptif et qualitatif, on observe que des indicateurs de processus résilients (estime de soi et qualité de vie) sont présents chez nos sujets ayant reçu un diagnostic de trouble démentiel lorsque leur déclin cognitif était mesuré au-dessus de 24/30 au MMS et que leur déclin cognitif n’est pas trop rapide. Nos sujets longitudinaux nous apprennent qu’il est important pour développer un processus résilient après une annonce diagnostique d’un trouble démentiel de pouvoir avoir :- La perception de se sentir utile pouvant être reliée en partie au regard que perçoit la personne de ‘l’autre sur son trouble démentiel.Le couple aidant patient nous apporte l’information qu’il est important d’accompagner les remaniements d’attachement qui peuvent s’effectuer à la suite de l’annonce et au cours de l’évolution de la maladie afin de sécuriser l’aidant, ce qui aidera à sécuriser le patientNotre étude conclut qu’un parcours résilient est possible malgré le trouble démentiel et peut être entravé ou favorisé par le parcours diagnostic. L’éducation thérapeutique ( ETP) qui se développe depuis quelques années dans le cadre des maladies chroniques comme le diabète et de manière plus timide et peu structurée, dans le domaine des troubles démentiels ; pourrait au regard des indicateurs de résilience identifiés dans notre étude , servir de tuteur de résilience au couple patient-aidant. L’ETP par un accompagnement multidisciplinaire, permettrait de développer une autonomie relative du patient face à sa maladie en le rendant plus acteur de son parcours et cela offrirait un cadre sécurisant pour les différents acteurs du processus diagnostic et pour l’aidant. / Our work in the field of health psychology focuses on the effects of the announcement of a diagnosis of dementia on the quality of life of the elderly in Bourg en Bresse ( France). We postulate that the manner in which announcement is made,could influence people’sexperience of the disease. Our study tries to examine the reactions of patients following this announcement.Several patient groups were developed for the study the effects of the announcement based on several criteria : cognitive impairment levels, attachment type, physician announcement style, timing of the announcement.Thus, a first group consisted of elderly people, referred to as the cross-sectional group ( that is to say, they were met once at the beginning at the time of their announcement or during their medical follow-up). A second group was the longitudinal group ( met at their announcement and then met every 3 months for almost 2 years for the longest follow-up) and the final control group, serving as a reference in order to understand the reactions of the patients.In order to complement the data from the previous groups, we also the caregivers of certain elderly people involved in the diagnostic process in order to study their reactions facing the announcement. Finally, we met with 3 groups of people also implicated in the announcement ( general practitioners, geriatricians and a family group) to study their language and impressions concerning the diagnostic announcement.The results show :- From a statistical point of vie, only the reactions of caregivers are significant in their more prevalent use of active coping : planning and in the use of mature defense mechanisms- Frome a statistical, descriptive and qualitative point of view, we observe that resilience indicators ( self-esteem and quality of life) are present in our subjects diagnosed with dementia when their cognitive decline is measured above 24/30 on the MMS and their cognitive decline is not too rapid.- Our longitudinal subjects show us that in order to be able to develop resilience after a diagnostic announcement of dementia, it is important to have :- A feeling of usefulness which can be linked, in part, to the way the person thinks other perceive his or her dementia disorder.

[pt] No Brasil, há uma falta de investimento em tratamentos psicossociais para demência. A Terapia de Estimulação Cognitiva (CST) é uma intervenção psicossocial baseada em evidências para pessoas que vivem com demência (PvcD) que foi adaptada e validada para vários países. Desenvolvida no Reino Unido, a CST envolve 14 sessões que acontecem ao longo de sete semanas. Seu objetivo é melhorar a função cognitiva por meio de atividades em grupo temáticas, que estimulam implicitamente as habilidades, incluindo memória, função executiva e linguagem. As sessões seguem um conjunto de princípios básicos que incluem estimulação mental, novas ideias, pensamentos e associações e opiniões em vez de fatos. Estudos sugerem que a CST pode melhorar a cognição, o humor, a qualidade de vida e as atividades de vida diária em PvcD leve a moderada. No Brasil, um ensaio controlado randomizado (RCT) buscou investigar a viabilidade da CST no país. Os resultados sugerem que aqueles que participaram dos grupos da CST apresentaram melhora significativa nas medidas relativas ao humor e às atividades de vida diária. Devido à pandemia COVID-19, foram feitas adaptações para que a CST pudesse ser oferecida virtualmente (vCST). O primeiro estudo foi realizado juntamente com o RCT para acessar a perspectiva dos participantes do grupo e explorar os efeitos da CST. Foram realizadas entrevistas individuais semiestruturadas com as PvcD que participaram dos grupos e seus cuidadores (n = 23). As transcrições das entrevistas foram analisadas por meio da Framework Analysis. A partir da análise, dois temas gerais, Benefícios pessoais de fazer parte do grupo e Mudanças na vida diária e sete subtemas, Benefícios para cuidadores, Benefícios para pessoas com demência, Memória, Sociabilidade, Linguagem, Humor, Orientação, Atividades cotidianas e Sintomas comportamentais e psicológicos. Os resultados indicam que a CST traz benefícios pessoais percebidos às PvcD e aos cuidadores, e há muitas melhorias percebidas, que são consistentes com achados qualitativos anteriores e apoiadas por achados empíricos de ensaios da CST. O segundo estudo teve como objetivo acessar a experiência e as perspectivas das PvcD que participaram de grupos da vCST e seus cuidadores (n =25), durante a pandemia do COVID-19. As informações qualitativas que surgiram da análise serão comparadas com dados quantitativos para entender a eficácia e a viabilidade do vCST. As transcrições das entrevistas foram analisadas por meio daFramework Analysis. A partir da análise, dois temas gerais, Benefícios pessoais defazer parte do grupo e Design da vCST e 12 subtemas, Prazer, Estimulação mental, Estimulação contínua, Ocupação, Cognição, Humor, Sociabilidade, On-line, Duração, Estrutura de sessões, Centrada na pessoa e Baseada em evidências. Os achados indicam que a VCST levou a melhorias percebidas para a PvcD e trouxe benefícios pessoais para aqueles que participaram dos grupos. Resultados semelhantes são encontrados em estudos da CST, que sugerem que a vCST é viável, como a intervenção presencial. / [en] In Brazil, there is a lack of investment in psychosocial treatments for dementia. Cognitive Stimulation Therapy (CST) is an evidence-based psychosocial intervention for people living with dementia (PlwD) that has been adapted and validated to several countries. Developed in the UK, it involves 14 sessions over seven weeks. It aims to improve cognitive function through themed group activities, which implicitly stimulate skills including memory, executive function and language. Sessions follow a set of guiding principles which include mental stimulation, new ideas, thoughts and associations and opinions rather than facts. Studies suggest that CST can improve cognition, mood, quality of life and activities of daily living in mild to moderate dementia. In Brazil, a randomized controlled trial (RCT) sought to investigate the feasibility of CST in the country. The results suggest that those who took part in the CST groups had a significant improvement in measures relative to mood and activities of daily living. Due to the COVID-19 pandemic, adaptations were made for virtual delivery, and virtual CST (vCST) groups are being conducted. The first study was conducted alongside the randomized RCT to explore the real-life effectiveness of CST and to access the perspective of group participants. Individual semi-structured interviews were applied to PlwD who took part in the groups and their care partners (n = 23). The transcripts of interviews were analysed using Framework Analysis. From the analysis, two general themes, Personal benefits of being part of the group and Changes to daily living and 7 subthemes, Benefits for caregivers, Benefits por people with dementia, Memory, Sociability, Language, Mood, Orientation, Everyday activities and Behavioural and psychological symptoms have emerged. Results indicate that CST brings perceived personal benefits to PlwD and caregivers, and there are many perceived improvements, which are consistent with previous qualitative findings and supported by empirical findings from CST trials. The second study aimed to access the experience and perspectives of Plwd who have participated in vCST groups and their care partners (n = 25), during the COVID-19 pandemic. Qualitative information that has emerged from the analysis will be compared with quantitative data to understand the effectiveness and feasibility of vCST. The transcripts of interviews were analysed using Framework Analysis. From the analysis, two general themes, Personal benefits of being part of the group and Design of vCST and 12 subthemes, Enjoyment, Mental stimulation, Continued stimulation, Occupation, Cognition, Mood, Sociability, Online, Duration, Structure of sessions, Person-centred and Evidence-based have emerged. The findings indicate that vCST led to perceived improvements for PlwD and personal benefits for those who took part in the groups. Similar results are found in CST studies, which suggest that vCST is viable as studies have suggested with the face-to-face intervention.

Au niveau du cerveau et dans le plasma de malades atteints de maladie d’Alzheimer (MA), l’accumulation de C22:0 et d’acides gras à très longue chaîne (C24:0 ; C26:0), la diminution d’acide docosahexaenoique (C22:6 n-3) et les modifications quantitatives et qualitatives de plasmalogènes suggèrent l’implication de dysfonctions peroxysomales. En fonction de ces constatations, les activités biologiques de C22:0, C24:0 et C26:0 ont été recherchées sur des cellules neuronales humaines SK-N-BE. La lipotoxicité des acides gras (C22:0, C24:0 et C26:0) induit divers effets au niveau des mitochondries (modifications topographiques, morphologiques et fonctionnelles), conduit à une rupture de l’équilibre RedOx (surproduction d’espèces radicalaires de l’oxygène, modification de l’activité des enzymes anti-oxydantes : catalase, SOD, GPx), à une peroxydation lipidique et à une désorganisation du cytosquelette (microfilaments d’actine, tubuline, neurofilaments). Ces acides affectent aussi l’amyloïdogenèse et la tauopathie. L’amyloïde béta favorise aussi l’accumulation intracellulaire de C22:0, C24:0 et C26:0. A fortes concentrations, ces acides gras induisent une mort cellulaire non apoptotique. Par ailleurs, les données immunohistochimiques en relation avec l’expression de marqueurs peroxysomaux (ABCD1, ABCD2, ABCD3, ACOX1 et catalase) au niveau du cerveau de souris transgéniques APP PS1 ΔE9 ainsi que les profil d’acide gras obtenus sur le cerveau et le sang de ces souris suggèrent qu’elles pourraient constituer un bon modèle pour l’étude des relations entre MA et métabolisme peroxysomal. L’étude clinique réalisée sur plasma et érythrocytes de malades déments (MA, démences vasculaires, autres démences) montre une forte accumulation de C22:0, C24:0 et C26:0. Le C26:0 pourrait constituer un excellent biomarqueur de la MA. Le C18:0 à est aussi augmenté ainsi que les acides gras n-6. De forts indices de stress oxydant sont aussi révélés. Dans son ensemble, le travail réalisé suggère que les acides gras (C22:0, C24:0 et C26:0) ainsi que le métabolisme des acides gras en relation avec le métabolisme peroxysomal pourraient contribuer à la neurodégénéréscence associée aux démences incluant la MA / In the brain and in the plasma of patients with Alzheimer’s disease (AD), marked accumulation of C22:0 and of very long chain fatty acids (C24:0 ; C26:0) have been reported. Important decreases of docosahexaenoic acid (DHA; C22:6 n-3) have also been described as well as quantitative and qualitative modifications of plasmalogens. Altogether, these lipid modifications suggest an implication of peroxisomal metabolism disorders in the physiopathology of AD. Therefore, the biological activities of C22:0, C24:0 and C26:0 have been studied on human neuronal cells SK-N-BE. On these cells, the lipotoxicity of fatty acids (C22:0, C24:0 and C26:0) leads to various cellular modifications: topographical, morphological and functional changes at the mitochondrial level, rupture of RedOx equilibrium (overproduction of reactive oxygen species, modification of the activity of enzymes involved in anti-oxidant defenses: catalase, SOD, GPx), lipid peroxidation, cytoskeleton disorganization (actin microfilaments, tubulin, neurofilaments). These fatty acids also favor amyloidogenesis and tauopathy. At elevated concentrations, these fatty acids trigger a non apoptotic mode of cell death. Moreover, data obtained by immunohistochemistry with antibodies raised against peroxisomal components (ABCD1, ABCD2, ABCD3, ACOX1 and catalase) on histological tissue sections of the brain of transgenic mice APP PS1 ΔE9 as well as lipidomic analysis performed on the blood and the brain of these mice suggest that they could constitute interesting model to study the relationships between AD and peroxisomal metabolism. The clinical study performed on the plasma and on the erythrocytes of patients with dementia (AD, vascular dementia, other dementia) revealed an important accumulation of C22:0, C24:0 and C26:0. Hexacosanoic acid (C26:0) might constitute an excellent biomarker of AD. The fatty acid C18:0 and (n-6) fatty acids have also been found at increased concentrations. A strong oxidative stress has also been revealed. Altogether, our data support that the fatty acids (C22:0, C24:0 and C26:0) as well as the fatty acid metabolism depending on the peroxisome might contribute to neurodegeneration leading to various types of dementia including AD